282 results on '"part 1"'
Search Results
2. Towards constraints on fossil fuel emissions from total column carbon dioxide
- Author
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Keppel-Aleks, G., Wennberg, P. O, O'Dell, C. W, and Wunch, D.
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Co2 Emissions ,Atmospheric Co2 ,Part 1 ,Space ,Surface ,Trends ,Sinks ,Consumption ,Sciamachy ,Transport - Published
- 2013
3. Explicit modeling of organic chemistry and secondary organic aerosol partitioning for Mexico City and its outflow plume
- Author
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Lee-Taylor, J., Madronich, S., Aumont, B., Baker, A., Camredon, M., Hodzic, A., Tyndall, G. S, Apel, E., and Zaveri, R. A
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vapor-pressure estimation ,milagro 2006 campaign ,mcma-2006 field campaign ,wrf-chem model ,atmospheric chemistry ,mass-spectrometry ,air-quality ,mirage-mex ,part 1 ,aromatic-hydrocarbons - Published
- 2011
4. Annual exposure to polycyclic aromatic hydrocarbons in urban environments linked to wintertime wood-burning episodes
- Author
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I. Tsiodra, G. Grivas, K. Tavernaraki, A. Bougiatioti, M. Apostolaki, D. Paraskevopoulou, A. Gogou, C. Parinos, K. Oikonomou, M. Tsagkaraki, P. Zarmpas, A. Nenes, and N. Mihalopoulos
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Atmospheric Science ,long-term measurements ,010504 meteorology & atmospheric sciences ,Physics ,QC1-999 ,source apportionment ,010501 environmental sciences ,01 natural sciences ,3. Good health ,part 1 ,carbonaceous aerosol ,Chemistry ,fine particulate matter ,13. Climate action ,11. Sustainability ,positive matrix factorization ,air-pollution ,chemical-composition ,biomass combustion ,QD1-999 ,0105 earth and related environmental sciences ,organic molecular markers - Abstract
Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants in fine particulate matter (PM) long known to have mutagenic and carcinogenic effects, but much is unknown about the importance of local and remote sources for PAH levels observed in population-dense urban environments. A year-long sampling campaign in Athens, Greece, where more than 150 samples were analyzed for 31 PAHs and a wide range of chemical markers, was combined with positive matrix factorization (PMF) to constrain the temporal variability, sources, and carcinogenic risk associated with PAHs. It was found that biomass burning (BB), a source mostly present during wintertime intense pollution events (observed for 18 % of measurement days in 2017), led to wintertime PAH levels that were 7 times higher than in other seasons and was as important for annual mean PAH concentrations (31 %) as diesel and oil (33 %) and gasoline (29 %) sources. The contribution of non-local sources, although limited on an annual basis (7 %), increased during summer, becoming comparable to that of local sources combined. The fraction of PAHs (12 members that were included in the PMF analysis) that was associated with BB was also linked to increased health risk compared to the other sources, accounting for almost half the annual PAH carcinogenic potential (43 %). This can result in a large number of excess cancer cases due to BB-related high PM levels and urges immediate action to reduce residential BB emissions in urban areas facing similar issues.
- Published
- 2021
5. Representation of precipitation and top-of-atmosphere radiation in a multi-model convection-permitting ensemble for the Lake Victoria Basin (East-Africa)
- Author
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Nicole P. M. van Lipzig, Jonas Van de Walle, Danijel Belušić, Ségolène Berthou, Erika Coppola, Matthias Demuzere, Andreas H. Fink, Declan L. Finney, Russell Glazer, Patrick Ludwig, John H. Marsham, Grigory Nikulin, Joaquim G. Pinto, David P. Rowell, Minchao Wu, and Wim Thiery
- Subjects
Kilometer-scale resolution ,Atmospheric Science ,ENVIRONMENT SIMULATOR JULES ,MODEL DESCRIPTION ,Science & Technology ,SIMPLE PARAMETERIZATION ,RWENZORI MOUNTAINS ,REGIONAL CLIMATE ,COSMO-CLM ,SCHEME ,Tropical deep convection ,Equatorial Africa ,Extreme weather events ,Convection permitting simulations ,PASSIVE MICROWAVE ,CLOUD ,Earth sciences ,Physical Sciences ,ddc:550 ,CORDEX Flagship Pilot Study ,Regional climate models ,Lake Victoria basin ,Meteorology & Atmospheric Sciences ,PART 1 - Abstract
The CORDEX Flagship Pilot Study ELVIC (climate Extremes in the Lake VICtoria basin) was recently established to investigate how extreme weather events will evolve in this region of the world and to provide improved information for the climate impact community. Here we assess the added value of the convection-permitting scale simulations on the representation of moist convective systems over and around Lake Victoria. With this aim, 10-year present-day model simulations were carried out with five regional climate models at both PARameterized (PAR) scales (12-25km) and Convection-Permitting (CP) scales (2.5-4.5km), with COSMO-CLM, RegCM, AROME, WRF and UKMO. Most substantial systematic improvements were found in metrics related to deep convection. For example, the timing of the daily maximum in precipitation is systematically delayed in CP compared to PAR models, thereby improving the agreement with observations. The large overestimation in the total number of rainy events is alleviated in the CP models. Systematic improvements were found in the diurnal cycle in Top-Of-Atmosphere (TOA) radiation and in some metrics for precipitation intensity. No unanimous improvement nor deterioration was found in the representation of the spatial distribution of total rainfall and the seasonal cycle when going to the CP scale. Furthermore, some substantial biases in TOA upward radiative fluxes remain. Generally our analysis indicates that the representation of the convective systems is strongly improved in CP compared to PAR models, giving confidence that the models are valuable tools for studying how extreme precipitation events may evolve in the future in the Lake Victoria basin and its surroundings.
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- 2022
- Full Text
- View/download PDF
6. Comprehensive detection of analytes in large chromatographic datasets by coupling factor analysis with a decision tree
- Author
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Kim, Sungwoo, Lerner, Brian M., Sueper, Donna T., Isaacman-VanWertz, Gabriel, Kim, Sungwoo, Lerner, Brian M., Sueper, Donna T., and Isaacman-VanWertz, Gabriel
- Abstract
Environmental samples typically contain hundreds or thousands of unique organic compounds, and even minor components may provide valuable insight into their sources and transformations. To understand atmospheric processes, individual components are frequently identified and quantified using gas chromatography-mass spectrometry. However, due to the complexity and frequently variable nature of such data, data reduction is a significant bottleneck in analysis. Consequently, only a subset of known analytes is often reported for a dataset, and large amounts of potentially useful data are discarded. We present an automated approach of cataloging and potentially identifying all analytes in a large chromatographic dataset and demonstrate the utility of our approach in an analysis of ambient aerosols. We use a coupled factor analysis-decision tree approach to deconvolute peaks and comprehensively catalog nearly all analytes in a dataset. Positive matrix factorization (PMF) of small subsections of multiple chromatograms is applied to extract factors that represent chromatographic profiles and mass spectra of potential analytes, in which peaks are detected. A decision tree based on peak parameters (e.g., location, width, and height), relative ratios of those parameters, peak shape, noise, retention time, and mass spectrum is applied to discard erroneous peaks and combine peaks determined to represent the same analyte. With our approach, all analytes within the small section of the chromatogram are cataloged, and the process is repeated for overlapping sections across the chromatogram, generating a complete list of the retention times and estimated mass spectra of all peaks in a dataset. We validate this approach using samples of known compounds and demonstrate the separation of poorly resolved peaks with similar mass spectra and the resolution of peaks that appear in only a fraction of chromatograms. As a case study, this method is applied to a complex real-world dataset of th
- Published
- 2022
7. Second-Trimester Constituents of the Metabolic Syndrome and Pregnancy Outcome: An Observational Cohort Study
- Author
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Jonas Ellerbrock, Esmee Hubers, Chahinda Ghossein-Doha, Veronique Schiffer, Robert-Jan Alers, Laura Jorissen, Jolijn van Neer, Maartje Zelis, Emma Janssen, Sabine Landewé-Cleuren, Annemie van Haarlem, Boris Kramer, Marc Spaanderman, RS: GROW - R4 - Reproductive and Perinatal Medicine, Obstetrie & Gynaecologie, MUMC+: MA Med Staf Artsass Cardiologie (9), MUMC+: MA Arts Assistenten Obstetrie Gynaecologie (9), RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy, MUMC+: MA Medische Staf Obstetrie Gynaecologie (9), MUMC+: TPZ Diabetes Zorg (9), RS: MHeNs - R3 - Neuroscience, Kindergeneeskunde, and MUMC+: MA Medische Staf Kindergeneeskunde (9)
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obesity ,hypertension ,BLOOD-PRESSURE ,DIAGNOSIS ,metabolic syndrome ,CLASSIFICATION ,Cohort Studies ,preeclampsia ,Pre-Eclampsia ,Pregnancy ,Risk Factors ,HYPERGLYCEMIA ,Humans ,PART 1 ,gestational diabetes ,dyslipidemia ,preterm birth ,RISK ,Nutrition and Dietetics ,Infant, Newborn ,Pregnancy Outcome ,PROTEINURIA ,WOMEN ,DIABETES-MELLITUS ,ASSOCIATION ,Diabetes, Gestational ,Diabetes Mellitus, Type 2 ,Pregnancy Trimester, Second ,Premature Birth ,Female ,Food Science - Abstract
Background: Gestational diabetes mellitus (GDM) increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) shows identical associations. The aim of this study was to evaluate the association between GDM, constituents of MetS and pregnancy outcomes. Methods: Of 2041 pregnant women undergoing an oral glucose tolerance test (OGTT) between 22 and 30 weeks of gestation, data were collected to evaluate the constituents of MetS. Odds ratios (ORs) were calculated to determine the associations between MetS and pregnancy outcomes. Results: GDM and obesity did not affect the risk of fetal growth abnormalities (SGA/LGA), preterm birth or preeclampsia (PE). Hypertension significantly increased the risk of SGA (OR—1.59), PE (OR—3.14), and preterm birth
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- 2022
8. Mechanistic modelling of two-phase slug flows with deposition
- Author
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Gabriel F.N. Gonçalves, Omar K. Matar, and Engineering & Physical Science Research Council (EPSRC)
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Wax ,Technology ,Engineering, Chemical ,PARAFFIN DEPOSITION ,PREDICTION ,General Chemical Engineering ,PIPELINES ,0904 Chemical Engineering ,WAX DEPOSITION ,Industrial and Manufacturing Engineering ,Mechanistic modelling ,Engineering ,HEAT-TRANSFER ,PRESSURE-DROP ,PART 1 ,Deposition ,Science & Technology ,MULTIPHASE FLOW ,Applied Mathematics ,0914 Resources Engineering and Extractive Metallurgy ,General Chemistry ,Slug flow ,Chemical Engineering ,SINGLE ,GAS ,Multiphase ,CFD ,0913 Mechanical Engineering - Abstract
Despite the large quantity of works dedicated to the analysis and modelling of deposition in single-phase flows, very few models have been proposed for deposition of solids in two-phase pipe flows of gas and liquid. A comprehensive mechanistic model for transient, multiphase pipe flow with phase change is proposed, which takes into account effects of deposition by mass diffusion, ageing, and shearing of the deposit layer. Validation is performed with an exhaustive database of experimental data from the literature, for steady and transient flows without deposition, and deposit thickness measurements for single-phase, slug and stratified flows. Most of the predictions are within a 20% error band from the experimental data, with slightly worse performance in the case of deposition in slug flows. A surrogate model is also developed based on active-learning sampling of the simulator results, demonstrating a technique that could be used for optimization or design of engineering devices.
- Published
- 2022
9. Pan-Arctic surface ozone: modelling vs. measurements
- Author
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Mika Vestenius, Sara Morris, Xiaoyi Zhao, Kimberly Strong, Irina Petropavlovskikh, Taneil Uttal, Xin Yang, Anne-M. Blechschmidt, Audra McClure-Begley, Andreas Richter, Kristof Bognar, Henrik Skov, and David W. Tarasick
- Subjects
Atmospheric Science ,TROPOSPHERIC BRO COLUMNS ,010504 meteorology & atmospheric sciences ,BROMINE EXPLOSION EVENT ,SEA-SALT AEROSOL ,010501 environmental sciences ,CHEMICAL-COMPOSITION ,Atmospheric sciences ,01 natural sciences ,lcsh:Chemistry ,Atmosphere ,Troposphere ,DRY DEPOSITION ,DEPLETION EPISODES ,Sea ice ,PART 1 ,Blowing snow ,0105 earth and related environmental sciences ,TROPICAL DEEP CONVECTION ,ATMOSPHERIC BOUNDARY-LAYER ,VERTICAL-DISTRIBUTION ,geography ,geography.geographical_feature_category ,Differential optical absorption spectroscopy ,Sea spray ,Ozone depletion ,lcsh:QC1-999 ,lcsh:QD1-999 ,Arctic ,13. Climate action ,lcsh:Physics - Abstract
Within the framework of the International Arctic Systems for Observing the Atmosphere (IASOA), we report a modelling-based study on surface ozone across the Arctic. We use surface ozone from six sites – Summit (Greenland), Pallas (Finland), Barrow (USA), Alert (Canada), Tiksi (Russia), and Villum Research Station (VRS) at Station Nord (North Greenland, Danish realm) – and ozone-sonde data from three Canadian sites: Resolute, Eureka, and Alert. Two global chemistry models – a global chemistry transport model (parallelised-Tropospheric Offline Model of Chemistry and Transport, p-TOMCAT) and a global chemistry climate model (United Kingdom Chemistry and Aerosol, UKCA) – are used for model data comparisons. Remotely sensed data of BrO from the GOME-2 satellite instrument and ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) at Eureka, Canada, are used for model validation. The observed climatology data show that spring surface ozone at coastal sites is heavily depleted, making ozone seasonality at Arctic coastal sites distinctly different from that at inland sites. Model simulations show that surface ozone can be greatly reduced by bromine chemistry. In April, bromine chemistry can cause a net ozone loss (monthly mean) of 10–20 ppbv, with almost half attributable to open-ocean-sourced bromine and the rest to sea-ice-sourced bromine. However, the open-ocean-sourced bromine, via sea spray bromide depletion, cannot by itself produce ozone depletion events (ODEs; defined as ozone volume mixing ratios, VMRs, < 10 ppbv). In contrast, sea-ice-sourced bromine, via sea salt aerosol (SSA) production from blowing snow, can produce ODEs even without bromine from sea spray, highlighting the importance of sea ice surface in polar boundary layer chemistry. Modelled total inorganic bromine (BrY) over the Arctic sea ice is sensitive to model configuration; e.g. under the same bromine loading, BrY in the Arctic spring boundary layer in the p-TOMCAT control run (i.e. with all bromine emissions) can be 2 times that in the UKCA control run. Despite the model differences, both model control runs can successfully reproduce large bromine explosion events (BEEs) and ODEs in polar spring. Model-integrated tropospheric-column BrO generally matches GOME-2 tropospheric columns within ∼ 50 % in UKCA and a factor of 2 in p-TOMCAT. The success of the models in reproducing both ODEs and BEEs in the Arctic indicates that the relevant parameterizations implemented in the models work reasonably well, which supports the proposed mechanism of SSA production and bromide release on sea ice. Given that sea ice is a large source of SSA and halogens, changes in sea ice type and extent in a warming climate will influence Arctic boundary layer chemistry, including the oxidation of atmospheric elemental mercury. Note that this work dose not necessary rule out other possibilities that may act as a source of reactive bromine from the sea ice zone.
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- 2020
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10. On the Calibration of Spatially Distributed Hydrologic Models for Poorly Gauged Basins: Exploiting Information from Streamflow Signatures and Remote Sensing-Based Evapotranspiration Data
- Author
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Tadesse Alemayehu, Hoshin V. Gupta, Ann van Griensven, Willy Bauwens, Hydrology and Hydraulic Engineering, Vriendenkring VUB, and Earth System Sciences
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Geography, Planning and Development ,evapotranspiration ,Environmental Sciences & Ecology ,flow duration curve ,Aquatic Science ,Biochemistry ,remote sensing ,hydrologic modeling ,MULTIPLE ,poorly gauged basin ,SWAT ,multi-objective and multi-variable calibration ,PART 1 ,RAINFALL ,Water Science and Technology ,Science & Technology ,CLIMATE-CHANGE ,FRAMEWORK ,SOIL ,Physical Sciences ,WATER-BALANCE ,Water Resources ,Life Sciences & Biomedicine ,LAND-USE DATA ,Environmental Sciences ,MARA RIVER-BASIN ,BEHAVIOR - Abstract
Spatially distributed hydrologic models are useful for understanding the water balance dynamics of catchments under changing conditions, thereby providing important information for water resource management and decision making. However, in poorly gauged basins, the absence of reliable and overlapping in situ hydro-meteorological data makes the calibration and evaluation of such models quite challenging. Here, we explored the potential of using streamflow signatures extracted from historical (not current) streamflow data, along with current remote sensing-based evapotranspiration data, to constrain the parameters of a spatially distributed Soil and Water Assessment Tool (SWAT) model of the Mara River Basin (Kenya/Tanzania) that is forced by satellite-based rainfall. The result is a reduced bias of the simulated estimates of streamflow and evapotranspiration. In addition, the simulated water balance dynamics better reflect underlying governing factors such as soil type, land cover and climate at both annual and seasonal time scales, indicating the structural and behavioral consistency of the calibrated model. This study demonstrates that the judicious use of available information can help to facilitate meaningful calibration and evaluation of hydrologic models to support decision making in poorly gauged river basins around the world.
- Published
- 2022
11. Comprehensive detection of analytes in large chromatographic datasets by coupling factor analysis with a decision tree
- Author
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Sungwoo Kim, Brian M. Lerner, Donna T. Sueper, and Gabriel Isaacman-VanWertz
- Subjects
mass-spectral deconvolution ,Atmospheric Science ,model ,2-dimensional gas-chromatography ,aerosol ,positive matrix factorization ,identification system ,instrument ,resolution ,organic-compounds ,part 1 - Abstract
Environmental samples typically contain hundreds or thousands of unique organic compounds, and even minor components may provide valuable insight into their sources and transformations. To understand atmospheric processes, individual components are frequently identified and quantified using gas chromatography-mass spectrometry. However, due to the complexity and frequently variable nature of such data, data reduction is a significant bottleneck in analysis. Consequently, only a subset of known analytes is often reported for a dataset, and large amounts of potentially useful data are discarded. We present an automated approach of cataloging and potentially identifying all analytes in a large chromatographic dataset and demonstrate the utility of our approach in an analysis of ambient aerosols. We use a coupled factor analysis-decision tree approach to deconvolute peaks and comprehensively catalog nearly all analytes in a dataset. Positive matrix factorization (PMF) of small subsections of multiple chromatograms is applied to extract factors that represent chromatographic profiles and mass spectra of potential analytes, in which peaks are detected. A decision tree based on peak parameters (e.g., location, width, and height), relative ratios of those parameters, peak shape, noise, retention time, and mass spectrum is applied to discard erroneous peaks and combine peaks determined to represent the same analyte. With our approach, all analytes within the small section of the chromatogram are cataloged, and the process is repeated for overlapping sections across the chromatogram, generating a complete list of the retention times and estimated mass spectra of all peaks in a dataset. We validate this approach using samples of known compounds and demonstrate the separation of poorly resolved peaks with similar mass spectra and the resolution of peaks that appear in only a fraction of chromatograms. As a case study, this method is applied to a complex real-world dataset of the composition of atmospheric particles, in which more than 1100 unique chromatographic peaks are resolved, and the corresponding peak information along with mass spectra are cataloged. National Oceanic and Atmospheric Administration Small Business Innovative Research Program [WC133R18CN0064, NA21OAR0210294] Published version This work was supported by the National Oceanic and Atmospheric Administration Small Business Innovative Research Program (WC133R18CN0064 and NA21OAR0210294). We thank Chenyang Bi for assistance with generating laboratory data and Allen Goldstein for sharing ambient data.
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- 2022
12. Performance Characteristics in Textile Application of Photochromic Dye Capsules
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Seniha MORSÜMBÜL and Emriye Perrin AKÇAKOCA KUMBASAR
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Polyamide Fibers ,Malzeme Bilimleri, Tekstil ,Fabric Porosity ,Exhaustion ,Direct Coloration ,Uv-Protection ,Polyester ,fatigue resistance ,Part 1 ,Photochromism ,cotton ,Industrial and Manufacturing Engineering ,Ultraviolet Protection ,Photochromism,cotton,UV protection,washing durability,fatigue resistance ,General Materials Science ,Materials Science, Textiles ,UV protection ,washing durability - Abstract
Photochromic dyes which change their color with UV light, are water insoluble and sensitive to the environmental conditions. In order to be able to use these dyes in textile industry, the dyes are encapsulated with a polymer, and then the encapsulated photochromic dyes are applied onto the textile materials. The encapsulated photochromic dyes can show different properties according to the photochromic dye and polymer type, capsule size and the encapsulation method applied. In this study, the performance characteristics of different commercial photochromic dye capsules were investigated after the application onto cotton fabrics by pad-cure process. It was observed that the fabrics still provide UV protection at 50 + UPF level even after 20 washing cycles. The photochromic fabrics lost their color and UV protective properties at most 16% and 4%, respectively after 20 UV on-off cycles., 18-TKUAM-003, The authors would like to gratefully acknowledge Ege University, scientific research projects through the project no. 18-TKUAM-003 for financial support to this research project.
- Published
- 2022
13. Bioaerosols in the atmosphere at two sites in Northern Europe in spring 2021: Outline of an experimental campaign
- Author
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Mikhail Sofiev, Svetlana Sofieva, Julia Palamarchuk, Ingrida Šaulienė, Evgeny Kadantsev, Nina Atanasova, Yalda Fatahi, Rostislav Kouznetsov, Joel Kuula, Auste Noreikaite, Martina Peltonen, Timo Pihlajamäki, Annika Saarto, Julija Svirskaite, Linnea Toiviainen, Svyatoslav Tyuryakov, Laura Šukienė, Eija Asmi, Dennis Bamford, Antti-Pekka Hyvärinen, Ari Karppinen, Molecular and Integrative Biosciences Research Programme, Aerovirology Research Group, Department of Microbiology, Molecular Principles of Viruses, Biosciences, Institute of Biotechnology, General Microbiology, Structure of the Viral Universe, Ilmatieteen laitos, and Finnish Meteorological Institute
- Subjects
PANDA PREDICTION SYSTEM ,climate changes ,bioaerosols ,pollen ,fungal spores ,automatic pollen monitoring ,metagenomics ,eDNA ,3rd generation DNA sequencing ,ilman saastuminen ,air pollution ,MULTIMODEL ENSEMBLE SIMULATIONS ,AIR-QUALITY ,ALLERGENIC POLLEN ,Northern Europe ,Biochemistry ,DISPERSION ,Fungal spores ,PART 1 ,atmosphere (earth) ,sampling (inspection) ,Helsinki ,EASTERN CHINA ,näytteenotto ,1172 Environmental sciences ,General Environmental Science ,aerosolit ,ilmakehä ,Aerosols ,Air Pollutants ,DNA-analyysi ,Atmosphere ,Automatic pollen monitoring ,DNA ,ilmastonmuutokset ,3142 Public health care science, environmental and occupational health ,AIRBORNE BACTERIA ,Europe ,MODEL ,ilman epäpuhtaudet ,Pohjois-Eurooppa ,Pollen ,DNA analysis ,Seasons ,Bioaerosols ,Metagenomics ,ENVIRONMENTAL DNA ,air impurities and contaminants ,Environmental Monitoring - Abstract
A coordinated observational and modelling campaign targeting biogenic aerosols in the air was performed during spring 2021 at two locations in Northern Europe: Helsinki (Finland) and Siauliai (Lithuania), approximately 500 km from each other in north-south direction. The campaign started on March 1, 2021 in Siauliai (12 March in Helsinki) and continued till mid-May in Siauliai (end of May in Helsinki), thus recording the transition of the atmospheric biogenic aerosols profile from winter to summer. The observations included a variety of samplers working on different principles. The core of the program was based on 2- and 2.4--hourly sampling in Helsinki and Siauliai, respectively, with sticky slides (Hirst 24-h trap in Helsinki, Rapid-E slides in Siauliai). The slides were subsequently processed extracting the DNA from the collected aerosols, which was further sequenced using the 3-rd generation sequencing technology. The core sampling was accompanied with daily and daytime sampling using standard filter collectors. The hourly aerosol concentrations at the Helsinki monitoring site were obtained with a Poleno flow cytometer, which could recognize some of the aerosol types. The sampling campaign was supported by numerical modelling. For every sample, SILAM model was applied to calculate its footprint and to predict anthropogenic and natural aerosol concentrations, at both observation sites. The first results confirmed the feasibility of the DNA collection by the applied techniques: all but one delivered sufficient amount of DNA for the following analysis, in over 40% of the cases sufficient for direct DNA sequencing without the PCR step. A substantial variability of the DNA yield has been noticed, generally not following the diurnal variations of the total-aerosol concentrations, which themselves showed variability not related to daytime. An expected upward trend of the biological material amount towards summer was observed but the day-to-day variability was large. The campaign DNA analysis produced the first high-resolution dataset of bioaerosol composition in the North-European spring. It also highlighted the deficiency of generic DNA databases in applications to atmospheric biota: about 40% of samples were not identified with standard bioinformatic methods.
- Published
- 2022
14. Separation of isomeric cereal-derived arabinoxylan-oligosaccharides by collision induced dissociation-travelling wave ion mobility spectrometry-tandem mass spectrometry (CID-TWIMS-MS/MS)
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Henk A. Schols, Maija Tenkanen, Edwin J. Bakx, Minna Juvonen, Department of Food and Nutrition, and Carbohydrate Chemistry and Enzymology
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Collision-induced dissociation ,Ion-mobility spectrometry ,Tandem mass spectrometry ,116 Chemical sciences ,Analytical chemistry ,STRUCTURAL-ANALYSIS ,Oligosaccharides ,010402 general chemistry ,01 natural sciences ,Analytical Chemistry ,Ion ,CROSS-SECTIONS ,Fragmentation (mass spectrometry) ,Ionization ,Levensmiddelenchemie ,LINKAGE ,Tetrasaccharide ,PART 1 ,SPECTRA ,Arabinoxylan ,Trisaccharide ,VLAG ,chemistry.chemical_classification ,IDENTIFICATION ,Food Chemistry ,010401 analytical chemistry ,General Medicine ,Ion mobility spectrometry ,ANOMERS ,0104 chemical sciences ,DISACCHARIDES ,DIFFERENTIATION ,chemistry ,416 Food Science ,Xylans ,FRAGMENTATION ,Edible Grain ,Food Science - Abstract
The potential of travelling wave ion mobility spectroscopy in combination with collision induced dissociation tandem mass spectrometry (CID-TWIMS-MS/MS) to separate cereal-derived isomeric arabinoxylanoligosaccharides (A)XOS was investigated. Three trisaccharide, four tetrasaccharide, and four pentasaccharide (A)XOS isomers were analyzed by positive and negative ionization TWIMS-MS and CID-TWIMS-MS/MS. The triand pentasaccharide isomers were distinguishable by the ATDs of the precursor ions. The CID-TWIMS-MS/MS could separate most of the isomeric fragment ions produced from tetra- and pentasaccharide (A)XOS. Finally, the base peak mobility spectrum is introduced as a practical tool for (A)XOS fingerprinting.
- Published
- 2022
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15. Impact of type of tooth on outcome of non-surgical root canal treatment
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Anja Kotiranta, Erika Laukkanen, Miira M. Vehkalahti, Department of Oral and Maxillofacial Diseases, University of Helsinki, HUS Head and Neck Center, Clinicum, and Miira M Vehkalahti / Principal Investigator
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Male ,Molar ,Root canal ,Radiography ,Dentistry ,law.invention ,0302 clinical medicine ,Randomized controlled trial ,law ,Tooth type ,Outcome ,Permanent teeth ,Tooth, Nonvital ,Endodontic ,SUCCESS ,Middle Aged ,Root Canal Therapy ,Treatment Outcome ,medicine.anatomical_structure ,OF-THE-LITERATURE ,030220 oncology & carcinogenesis ,Retreatment ,Female ,TORONTO ,03 medical and health sciences ,stomatognathic system ,Root canal treatment ,medicine ,PART 1 ,Humans ,General Dentistry ,Anterior teeth ,Retrospective Studies ,Periodontitis ,GENERAL DENTAL PRACTITIONERS ,business.industry ,APICAL PERIODONTITIS ,Mean age ,030206 dentistry ,medicine.disease ,TREATED TEETH ,313 Dentistry ,Periapical index (PAI) ,stomatognathic diseases ,ENDODONTIC TREATMENT ,Dental Pulp Cavity ,PERIAPICAL STATUS ,FOLLOW-UP ,business ,Periapical Periodontitis - Abstract
Objectives We assessed the impact of type of tooth on the outcome of root canal treatment (RCT) according to factors potentially weakening the prognosis such as preoperative apical periodontitis (AP) and treatment modality (primary or secondary RCT). Materials and methods We scrutinized patient documents including pre- and postoperative radiographs of 640 permanent teeth receiving non-surgical RCT at Helsinki University Clinic in 2008–2011. Of teeth, 44% were molars, 32% premolars, and 24% anterior teeth. Patients’ mean age was 51.5 years; 51% were male. AP was present in 60.5% of teeth preoperatively. We used the periapical index (PAI) to assess the radiographs and defined radiographically “healthy” and “healing” cases as successful. Statistical evaluation included chi-squared tests, Fisher’s exact tests, t tests, and logistic regression modeling. Results The overall success rate (SR) was 84.1%; 88.3% for primary and 75.5% for secondary RCT (p
- Published
- 2019
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16. Diagnosis and Surgical Treatment of Idiopathic Primary Sino-Nasal Obstruction in Miniature Horse Breeds: Long-Term Follow-Up of Seven Cases
- Author
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Elke Pollaris, Lieven Vlaminck, Katrien Vanderperren, Els Raes, and W. Henry Tremaine
- Subjects
miniature horse breed ,medicine.medical_specialty ,040301 veterinary sciences ,Long term follow up ,bilateral sinus disease ,Nostril ,Radiography ,medicine.medical_treatment ,Veterinary medicine ,Perforation (oil well) ,Osteotomy ,DISEASE ,0403 veterinary science ,03 medical and health sciences ,0302 clinical medicine ,PARANASAL SINUS TUMORS ,SF600-1100 ,medicine ,otorhinolaryngologic diseases ,PART 1 ,FRONTONASAL BONE FLAP ,Veterinary Sciences ,030223 otorhinolaryngology ,Sinus (anatomy) ,Fixation (histology) ,Original Research ,General Veterinary ,business.industry ,idiopathic sinus pathology ,04 agricultural and veterinary sciences ,respiratory system ,EQUINE NASAL ,Surgery ,Ostium ,medicine.anatomical_structure ,idiopathic sino-nasal obstruction ,single caudally based front-nasal bone flap ,MUCOCELES ,Veterinary Science ,business - Abstract
Idiopathic sino-nasal obstruction resulting in retention of large amounts of liquid in the paranasal sinus compartments was diagnosed in seven young (2. 2 ± 0.7 years) miniature-breed horses based on clinical, endoscopic, radiographic, and CT scan examinations. The most prevalent clinical signs included decreased or no airflow from the nostril(s) (7/7) and nasal discharge (6/7). The problem presented bilaterally in six of seven cases. An alternative sino-nasal communication was created through bone flap osteotomy surgery and perforation of the ventromedial floor of the dorsal conchae in all cases, followed by fixation of silicone irrigation tubes/Foley catheters in six of seven cases to keep the newly created ostium patent. This resulted in long-term resolution of the problem with good cosmetic appearance in all animals following a median period of 19 months. Premature loss of fixed tubes was reported in three cases.
- Published
- 2021
17. Monitoring established Crohn's disease with pan-intestinal video capsule endoscopy in Europe: clinician consultation using the nominal group technique
- Author
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Lucian Negreanu, Nancy van Lent, Cristina Carretero, Marc Ferrante, Alan J Lobo, Salvatore Oliva, Ana Vojvodic, Franck Carbonnel, and Torben Knudsen
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2019-20 coronavirus outbreak ,medicine.medical_specialty ,COLONOSCOPY ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,BIOMARKERS ,Disease ,030204 cardiovascular system & hematology ,Research & Experimental Medicine ,DIAGNOSIS ,Capsule Endoscopy ,Video capsule endoscopy ,Crohn’s disease monitoring ,03 medical and health sciences ,Crohn's disease monitoring ,0302 clinical medicine ,Medicine, General & Internal ,FECAL CALPROTECTIN ,Crohn Disease ,Internal medicine ,General & Internal Medicine ,Nominal group technique ,EVIDENCE-BASED CONSENSUS ,MANAGEMENT ,Medicine ,Humans ,PART 1 ,EPIDEMIOLOGY ,030212 general & internal medicine ,Referral and Consultation ,Crohn's disease ,Science & Technology ,business.industry ,General Medicine ,medicine.disease ,digestive system diseases ,Europe ,Intestines ,Medicine, Research & Experimental ,nominal group technique ,pan-intestinal video capsule endoscopy ,business ,Life Sciences & Biomedicine ,PRIORITIES ,INFLAMMATORY-BOWEL-DISEASE - Abstract
OBJECTIVE: Monitoring established Crohn's disease (CD) through a "treat-to-target" strategy aims to reduce and prevent long-term bowel damage and disability. Despite the availability of different monitoring techniques, there is a current lack of integrated evidence to guide optimal monitoring in terms of appropriate tools and timing. Pan-intestinal video capsule endoscopy (PCE) enables non-invasive and direct visualization of the entire intestinal tract with proven safety and efficacy. This study aims to generate insights on the value of PCE for monitoring established CD from the physician's perspective. METHODS: The Nominal Group Technique (NGT) was used to create discussion around pre-defined research questions aimed at identifying target patient populations for PCE, benefits of PCE in terms of improving disease management, comparative benefits of PCE over standard of care, research priorities to ratify the use of PCE, and hurdles to PCE utilization. A NGT panel was held in Brussels, Belgium in October 2018 with 9 gastroenterology experts. Data were collected from multiple rankings of statements to the research questions and analyzed descriptively. RESULTS: Consensus indicated that PCE is differentiated from other diagnostic tools, allowing for non-invasive and direct visualization of the luminal intestinal tract in one single procedure. Participants agreed that PCE is beneficial for mapping and grading established CD in all patients, enabling individual and tailored treatment decision-making. Time required to read PCE results was identified as the main utilization hurdle by participants. Well-designed studies are needed to confirm improved outcomes amongst patients with CD managed through a PCE-guided approach. CONCLUSIONS: This study, using the NGT, generated expert opinion on the value of PCE for monitoring established CD in terms of target patient populations and benefits compared to other diagnostic modalities. Participants perceived PCE to facilitate a "treat-to-target" strategy for CD management. Further research is needed to support this value perception. ispartof: CURRENT MEDICAL RESEARCH AND OPINION vol:37 issue:9 pages:1547-1554 ispartof: location:England status: published
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- 2021
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18. LCA Practices of Plastics and Their Recycling: A Critical Review
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Timothy M. Kousemaker, Antonis I. Vakis, and Gerald H. Jonker
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Computer science ,0211 other engineering and technologies ,WASTE ,Context (language use) ,02 engineering and technology ,010501 environmental sciences ,Space (commercial competition) ,Dynamic modelling ,recycling ,01 natural sciences ,lcsh:Technology ,lcsh:Chemistry ,dynamic LCA ,multi method ,Order (exchange) ,dynamic modeling ,COMPOSITES ,PART 1 ,General Materials Science ,021108 energy ,Instrumentation ,Life-cycle assessment ,SUSTAINABILITY ASSESSMENT ,lcsh:QH301-705.5 ,0105 earth and related environmental sciences ,Fluid Flow and Transfer Processes ,lcsh:T ,Process Chemistry and Technology ,LCA ,General Engineering ,FRAMEWORK ,PACKAGING SYSTEMS ,lcsh:QC1-999 ,Computer Science Applications ,System dynamics ,LIFE-CYCLE ASSESSMENT ,Risk analysis (engineering) ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,Sustainability ,END ,Multi method ,IMPACT ASSESSMENT ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Physics ,policy - Abstract
In a bid to help address the environmental footprints associated with products and services, life cycle assessment (LCA) applications have become increasingly popular throughout the years. This review summarizes some important methodological developments in recent years, such as the advent of dynamic LCA, as well as highlighting recent LCA applications in the context of plastics/recycling with a focus on their methodological choices. Furthermore, this review aims to offer a set of possible research lines to improve the gap between LCA and decision-making (policy). It was found that the majority of reviewed papers are mostly conservative in their methodological practice, employing mostly static analyses and making little use of other methods. In order to bridge the gap between LCA and policy, it is suggested to broaden system boundaries through the integration of dynamic modelling methods, incorporating interactions between fore- and background systems, and including behavioral components where relevant. In addition, advanced sampling routines to further explore and assess the policy space are recommended. This is of paramount importance when dealing with recycling processes as the molecules/polymers constituting the output of those processes have to be benchmarked in terms of costs and, crucially, their sustainability character against virgin ones.
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- 2021
19. LCA Practices of Plastics and Their Recycling
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LCA ,WASTE ,recycling ,FRAMEWORK ,PACKAGING SYSTEMS ,LIFE-CYCLE ASSESSMENT ,dynamic LCA ,multi method ,dynamic modeling ,DYNAMIC LCA ,END ,COMPOSITES ,PART 1 ,IMPACT ASSESSMENT ,SUSTAINABILITY ASSESSMENT ,policy - Abstract
In a bid to help address the environmental footprints associated with products and services, life cycle assessment (LCA) applications have become increasingly popular throughout the years. This review summarizes some important methodological developments in recent years, such as the advent of dynamic LCA, as well as highlighting recent LCA applications in the context of plastics/recycling with a focus on their methodological choices. Furthermore, this review aims to offer a set of possible research lines to improve the gap between LCA and decision-making (policy). It was found that the majority of reviewed papers are mostly conservative in their methodological practice, employing mostly static analyses and making little use of other methods. In order to bridge the gap between LCA and policy, it is suggested to broaden system boundaries through the integration of dynamic modelling methods, incorporating interactions between fore- and background systems, and including behavioral components where relevant. In addition, advanced sampling routines to further explore and assess the policy space are recommended. This is of paramount importance when dealing with recycling processes as the molecules/polymers constituting the output of those processes have to be benchmarked in terms of costs and, crucially, their sustainability character against virgin ones.
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- 2021
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20. Fracture resistance of equine cheek teeth with and without occlusal fissures : a standardized ex vivo model
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Elke Pollaris, Rita Cauwels, Bart J. G. Broeckx, Sivaprakash Rajasekharan, and Lieven Vlaminck
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SURFACE ,medicine.medical_treatment ,Veterinary medicine ,cheek tooth ,PULPAR EXPOSURE ,HORSES ,Crown (dentistry) ,stomatognathic system ,Cheek teeth ,SF600-1100 ,THICKNESS ,medicine ,Periodontal fiber ,PART 1 ,Maxillary central incisor ,Veterinary Sciences ,APICAL INFECTIONS ,Original Research ,equine ,Orthodontics ,General Veterinary ,business.industry ,fracture resistance ,medicine.disease ,PERIODONTAL-LIGAMENT ,Masticatory force ,stomatognathic diseases ,MASTICATORY FORCES ,fracture ,Tooth pathology ,Fracture (geology) ,Pulp (tooth) ,MORPHOLOGY ,Veterinary Science ,fissure ,SECONDARY DENTIN ,business - Abstract
Background:Ex vivo fracture models are frequently used in human dentistry to provide insights in the fracture mechanisms of teeth. Equine cheek teeth fractures are an important dental pathology, but there has been no research performed to examine the fracture resistance ex vivo.Objective: To evaluate the fracture resistance of equine cheek teeth and identify anatomical predictors that might influence fracture resistance in healthy teeth. It was further evaluated if the presence of a fissure caused a decrease in fracture resistance.Study design:Ex vivo experimental design.Methods: Individual cheek teeth were subjected to a compression load in a universal testing machine until fracture occurred. Testing was performed in two study groups. A first group of healthy cheek teeth was tested to examine anatomical predictors on fracture resistance. A second group comprised cheek teeth with occlusal fissures and an equal number of age- and size-matched fissure-free teeth as controls. The effect of possible predictors on fracture resistance was investigated by regression analysis.Results: In the first group, fracture resistance was significantly influenced by the location on the tooth where testing was performed in both maxillary (p < 0.001) and mandibular teeth (p < 0.001). Additional significantly associated factors were Triadan number in mandibular (p = 0.009) and the mesiodistal length of the occlusal surface of maxillary teeth (p = 0.01). Experimentally induced crown fractures that extended below the simulated bone level were more frequently associated with pulp horn exposure (p < 0.001). In the second group, significant lower fracture loads were recorded in teeth with fissures (mandibular p = 0.006; maxillary p < 0.001), compared to fissure-free teeth.Main limitations: This ex vivo model does not imitate the in vivo masticatory forces and lacks the shock-absorbing properties of the periodontal ligament.Conclusions: The methodology used in this study provides an ex vivo experimental set-up to test fracture resistance of equine cheek teeth enabling evidence-based research to examine the potentially weakening effects of tooth pathology and its treatments. Crown resistance to fracture differed along the occlusal surface of healthy equine cheek teeth, and the presence of fissures further decreased fracture resistance.
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- 2021
21. Şizofreni Tedavisinde Akut ve Sürdürüm Döneminde İlaç Tedavisi
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Kirli, Umut and Alptekin, Koksal
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Biological-Psychiatry Wfsbp ,Clinical-Practice Guidelines ,World-Federation ,psychotic disorders ,Schizoaffective Disorder ,Update 2012 ,Schizophrenia ,Part 1 ,Remitted 1st-Episode Psychosis ,Negative Symptoms ,Pharmacological-Treatment ,Long-Term Treatment ,drug therapy - Abstract
Schizophrenia is one of the leading disorders causing impairment in society. Therefore, it is crucial to review evidence-based treatment approaches which are both effective and causing minimum side effects. In this paper, treatment recommendations for first episode schizophrenia, patients in acute phase with a history of multiple episodes, and patients in the maintenance phase will be discussed in light of the Psychiatric Association of Turkey Guideline for Treatment of Schizophrenia, other recent national and international guidelines as well as expert consensus reports in the literature. Finally, practical considerations will be suggested.
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- 2021
22. ISB recommendations for skin-marker-based multi-segment foot kinematics
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Paolo Caravaggi, Julie Stebbins, Alberto Leardini, Howard J. Hillstrom, Kevin Deschamps, and Anton Arndt
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Technology ,Kinematics ,ANKLE KINEMATICS ,MOTION ,Computer science ,0206 medical engineering ,Biomedical Engineering ,Biophysics ,JOINT COORDINATE SYSTEM ,02 engineering and technology ,Skin markers ,NORMAL GAIT ,Motion (physics) ,Multi-segment models ,Terminology ,Foot joints ,Set (abstract data type) ,03 medical and health sciences ,Engineering ,0302 clinical medicine ,Foot Joints ,SYSTEMS METHOD REPEATABILITY ,PART 1 ,Orthopedics and Sports Medicine ,Engineering, Biomedical ,Gait ,IN-VIVO ,Skin ,Foot (prosody) ,Protocol (science) ,Science & Technology ,STANCE PHASE ,Information retrieval ,Data collection ,Foot ,Rehabilitation ,020601 biomedical engineering ,Biomechanical Phenomena ,MODEL ,MULTISEGMENT FOOT ,Gait analysis ,Life Sciences & Biomedicine ,030217 neurology & neurosurgery - Abstract
The foot is anatomically and functionally complex, and thus an accurate description of intrinsic kinematics for clinical or sports applications requires multiple segments. This has led to the development of many multi-segment foot models for both kinematic and kinetic analyses. These models differ in the number of segments analyzed, bony landmarks identified, required marker set, defined anatomical axes and frames, the convention used to calculate joint rotations and the determination of neutral positions or other offsets from neutral. Many of these models lack validation. The terminology used is inconsistent and frequently confusing. Biomechanical and clinical studies using these models should use established references and describe how results are obtained and reported. The International Society of Biomechanics has previously published proposals for standards regarding kinematic and kinetic measurements in biomechanical research, and in this paper also addresses multi-segment foot kinematics modeling. The scope of this work is not to prescribe a particular set of standard definitions to be used in all applications, but rather to recommend a set of standards for collecting, calculating and reporting relevant data. The present paper includes recommendations for the overall modeling and grouping of the foot bones, for defining landmarks and other anatomical references, for addressing the many experimental issues in motion data collection, for analysing and reporting relevant results and finally for designing clinical and biomechanical studies in large populations by selecting the most suitable protocol for the specific application. These recommendations should also be applied when writing manuscripts and abstracts. ispartof: JOURNAL OF BIOMECHANICS vol:125 ispartof: location:United States status: published
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- 2020
23. Occlusal Fissures in Equine Cheek Teeth: A Prospective Longitudinal in vivo Study
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Elke Pollaris, Lieven Vlaminck, and Bart J. G. Broeckx
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040301 veterinary sciences ,Tooth Fracture ,Dentistry ,Equine dentistry ,HORSES ,DISEASE ,equine dentistry ,0403 veterinary science ,03 medical and health sciences ,INFUNDIBULAE ,FRACTURES ,stomatognathic system ,Cheek teeth ,Medicine ,PART 1 ,LOCATION ,Significant risk ,Veterinary Sciences ,APICAL INFECTIONS ,030304 developmental biology ,0303 health sciences ,LESIONS ,lcsh:Veterinary medicine ,General Veterinary ,Mandibular teeth ,business.industry ,crown fracture ,04 agricultural and veterinary sciences ,Cheek ,idiopathic cheek teeth fractures ,PREVALENCE ,stomatognathic diseases ,medicine.anatomical_structure ,Pulp (tooth) ,lcsh:SF600-1100 ,ETIOPATHOLOGICAL FINDINGS ,fissure ,Partial Crown ,business ,cheek teeth - Abstract
Background: It has been suggested that fissures of the occlusal surface of equine cheek teeth may develop into crown fractures. Objectives: To examine the evolution of fissures present on the occlusal surface of cheek teeth. Furthermore, to investigate the presence of a fissure as a risk factor for the development of a subsequent crown fracture. Study Design: Observational longitudinal study. Methods: Bi-annual dental examinations were performed on 36 horses for 3 years. Video-recordings were made to evaluate the evolution of detected fissures. The effect of possible predictors on the development of tooth fractures was investigated by regression analysis. Results: The evolution of 785 fissures (467 type 1a, 271 type 1b, 47 type 2) was recorded. Fissure characteristics were observed to remain unchanged, disappear, become longer, shorter, change in configuration or change in color. Partial crown fractures (22 maxillary, 50 mandibular) were recorded in 52 cheek teeth in 22/36 horses. Fifty-nine of these fractures evolved from previously observed fissures (24 type 1a, 29 type 1b, 6 type 2). All fissure types proved to be a significant risk factor for the development of a crown fracture (p < 0.001), with the highest odds for type 2 fissures (OR = 14.27; 95% CI = 4.88-41.71). Other significant risk factors were the time of follow-up (p < 0.001), mandibular teeth (p < 0.001) and the lingual side of a tooth (p < 0.001). All fractures were non-complicated. Main Limitations: Some horses were prematurely lost for follow-up, which perhaps influenced the results. A longer follow-up period would have also allowed an evaluation of the risk for pulp disease on the long term subsequent to partial crown fractures. Conclusions: The presence of a fissure of any type, mandibular cheek teeth, the lingual side of cheek teeth, and time of follow-up proved to be significant risk factors for development of a cheek tooth crown fracture. Type 2 fissures showed the highest odds followed by type 1b fissures. The observed partial crown fractures demonstrated a low clinical impact whereby no tooth showed signs of development of endodontal disease.
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- 2020
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24. Coupling interactive fire with atmospheric composition and climate in the UK Earth System Model
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Joao C. Teixeira, Nadine Unger, Gerd A. Folberth, Apostolos Voulgarakis, and Fiona M. O'Connor
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ENVIRONMENT SIMULATOR JULES ,Peat ,SAVANNA ,TRACE GASES ,AIR-QUALITY ,04 Earth Sciences ,UK's Earth System Model (UKESM1) ,Atmospheric sciences ,Carbon cycle ,CHEMISTRY ,PART 1 ,Geosciences, Multidisciplinary ,FOREST-FIRE ,QE1-996.5 ,Science & Technology ,LAND-USE ,INteractive Fires and Emissions algoRithm for Natural envirOnments (INFERNO) fire model ,AEROSOL ,Geology ,Radiative forcing ,Fire–composition–climate Earth system (ES) model ,AERONET ,Aerosol ,Earth system science ,Atmospheric chemistry ,Physical Sciences ,Environmental science ,Moderate-resolution imaging spectroradiometer ,BIOMASS-BURNING EMISSIONS - Abstract
Summarization: Fire constitutes a key process in the Earth system (ES), being driven by climate as well as affecting the climate by changing atmospheric composition and impacting the terrestrial carbon cycle. However, studies on the effects of fires on atmospheric composition, radiative forcing and climate have been limited to date, as the current generation of ES models (ESMs) does not include fully atmosphere–composition–vegetation coupled fires feedbacks. The aim of this work is to develop and evaluate a fully coupled fire–composition–climate ES model. For this, the INteractive Fires and Emissions algoRithm for Natural envirOnments (INFERNO) fire model is coupled to the atmosphere-only configuration of the UK's Earth System Model (UKESM1). This fire–atmosphere interaction through atmospheric chemistry and aerosols allows for fire emissions to influence radiation, clouds and generally weather, which can consequently influence the meteorological drivers of fire. Additionally, INFERNO is updated based on recent developments in the literature to improve the representation of human and/or economic factors in the anthropogenic ignition and suppression of fire. This work presents an assessment of the effects of interactive fire coupling on atmospheric composition and climate compared to the standard UKESM1 configuration that uses prescribed fire emissions. Results show a similar performance when using the fire–atmosphere coupling (the “online” version of the model) when compared to the offline UKESM1 that uses prescribed fire. The model can reproduce observed present-day global fire emissions of carbon monoxide (CO) and aerosols, despite underestimating the global average burnt area. However, at a regional scale, there is an overestimation of fire emissions over Africa due to the misrepresentation of the underlying vegetation types and an underestimation over equatorial Asia due to a lack of representation of peat fires. Despite this, comparing model results with observations of CO column mixing ratio and aerosol optical depth (AOD) show that the fire–atmosphere coupled configuration has a similar performance when compared to UKESM1. In fact, including the interactive biomass burning emissions improves the interannual CO atmospheric column variability and consequently its seasonality over the main biomass burning regions – Africa and South America. Similarly, for aerosols, the AOD results broadly agree with the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic Network (AERONET) observations. Presented on: Geoscientific Model Development
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- 2020
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25. A Review on Finite Element Modeling and Simulation of the Anterior Cruciate Ligament Reconstruction
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L. A. Spyrou, Konstantinos Moustakas, Dimitar Stanev, Lefteris Benos, and Dimitrios Tsaopoulos
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0301 basic medicine ,Histology ,Anterior cruciate ligament reconstruction ,current trends ,Computer science ,Anterior cruciate ligament ,medicine.medical_treatment ,lcsh:Biotechnology ,graft type ,Biomedical Engineering ,Patellofemoral joint ,Bioengineering ,02 engineering and technology ,screw fixation ,Review ,finite element analysis ,Knee Joint ,part 1 ,03 medical and health sciences ,graft stiffness ,Double bundle ,lcsh:TP248.13-248.65 ,medicine ,graft modeling ,knee-joint ,Orthodontics ,graft fixation ,graft pretension ,human patellar tendon ,Multidisciplinary Collaboration ,Soft tissue ,Bioengineering and Biotechnology ,021001 nanoscience & nanotechnology ,Finite element method ,ACL reconstruction ,030104 developmental biology ,medicine.anatomical_structure ,biomechanical evaluation ,double-bundle ,hamstring tendons ,0210 nano-technology ,Biotechnology - Abstract
The anterior cruciate ligament (ACL) constitutes one of the most important stabilizing tissues of the knee joint whose rapture is very prevalent. ACL reconstruction (ACLR) from a graft is a surgery which yields the best outcome. Taking into account the complicated nature of this operation and the high cost of experiments, finite element (FE) simulations can become a valuable tool for evaluating the surgery in a pre-clinical setting. The present study summarizes, for the first time, the current advancement in ACLR in both clinical and computational level. It also emphasizes on the material modeling and properties of the most popular grafts as well as modeling of different surgery techniques. It can be concluded that more effort is needed to be put toward more realistic simulation of the surgery, including also the use of two bundles for graft representation, graft pretension and artificial grafts. Furthermore, muscles and synovial fluid need to be included, while patellofemoral joint is an important bone that is rarely used. More realistic models are also required for soft tissues, as most articles used isotropic linear elastic models and springs. In summary, accurate and realistic FE analysis in conjunction with multidisciplinary collaboration could contribute to ACLR improvement provided that several important aspects are carefully considered.
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- 2020
26. Hip Joint Torsional Loading Before and After Cam Femoroacetabular Impingement Surgery
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Ferdinando Rodriguez y Baena, Marcus J K Bankes, Hadi El Daou, Jonathan R.T. Jeffers, K. C. Geoffrey Ng, Engineering & Physical Science Research Council (EPSRC), and Engineering & Physical Science Research Council (E
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Male ,MOTION ,medicine.medical_treatment ,1106 Human Movement and Sports Sciences ,0302 clinical medicine ,0903 Biomedical Engineering ,Femoracetabular Impingement ,Medicine ,Orthopedics and Sports Medicine ,Range of Motion, Articular ,030222 orthopedics ,OUTCOMES ,T-CAPSULOTOMY ,in vitro ,Articles ,Robotics ,Middle Aged ,Biomechanical Phenomena ,Cam deformity ,Capsulotomy ,Hip Joint ,Life Sciences & Biomedicine ,0913 Mechanical Engineering ,musculoskeletal diseases ,medicine.medical_specialty ,cam ,Rotation ,capsule ,Movement ,Physical Therapy, Sports Therapy and Rehabilitation ,03 medical and health sciences ,Cadaver ,PART 1 ,Humans ,RECONSTRUCTION ,Joint (geology) ,Femoroacetabular impingement ,femoroacetabular impingement ,CAPSULAR REPAIR ,Science & Technology ,business.industry ,Hip and Thigh ,robot ,medicine.disease ,Surgery ,Orthopedics ,PROSPECTIVE COHORT ,Torque ,OSTEOARTHRITIS ,business ,ARTHROSCOPIC TREATMENT ,DEFORMITY ,Sport Sciences ,Joint Capsule - Abstract
Background:Surgical management of cam femoroacetabular impingement (FAI) aims to preserve the native hip and restore joint function, although it is unclear how the capsulotomy, cam deformity, and capsular repair influence joint mechanics to balance functional mobility.Purpose:To examine the contributions of the capsule and cam deformity to hip joint mechanics. Using in vitro, cadaveric methods, we examined the individual effects of the surgical capsulotomy, cam resection, and capsular repair on passive range of motion and resistance of applied torque.Study Design:Descriptive laboratory study.Methods:Twelve cadaveric hips with cam deformities were skeletonized to the capsule and mounted onto a robotic testing platform. The robot positioned each intact hip in multiple testing positions: (1) extension, (2) neutral 0°, (3) flexion 30°, (4) flexion 90°, (5) flexion-adduction and internal rotation (FADIR), and (6) flexion-abduction and external rotation. Then the robot performed applicable internal and external rotations, recording the neutral path of motion until a 5-N·m of torque was reached in each rotational direction. Each hip then underwent a series of surgical stages (T-capsulotomy, cam resection, capsular repair) and was retested to reach 5 N·m of internal and external torque again after each stage. During the capsulotomy and cam resection stages, the initial intact hip’s recorded path of motion was replayed to measure changes in resisted torque.Results:Regarding changes in motion, external rotation increased substantially after capsulotomies, but internal rotation only further increased at flexion 90° (change +32%, P = .001, d = 0.58) and FADIR (change +33%, P < .001, d = 0.51) after cam resections. Capsular repair provided marginal restraint for internal rotation but restrained the external rotation compared with the capsulotomy stage. Regarding changes in torque, both internal and external torque resistance decreased after capsulotomy. Compared with the capsulotomy stage, cam resection further reduced internal torque resistance during flexion 90° (change −45%, P < .001, d = 0.98) and FADIR (change −37%, P = .003, d = 1.0), where the cam deformity accounted for 21% of the intact hip’s torsional resistance in flexion 90° and 27% in FADIR.Conclusion:Although the capsule played a predominant role in joint constraint, the cam deformity provided 21% to 27% of the intact hip’s resistance to torsional load in flexion and internal rotation. Resecting the cam deformity would remove this loading on the chondrolabral junction.Clinical Relevance:These findings are the first to quantify the contribution of the cam deformity to resisting hip joint torsional loads and thus quantify the reduced loading on the chondrolabral complex that can be achieved after cam resection.
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- 2018
27. A generic tool for quantifying the energy requirements of glasshouse food production
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Christos N. Markides, Solomos Georgiou, Salvador Acha, Nilay Shah, Natural Environment Research Council, Engineering & Physical Science Research Council (EPSRC), and Sainsbury's Supermarkets Ltd
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Technology ,Food industry ,DEMAND ,020209 energy ,Strategy and Management ,Supply chain ,Environmental Sciences & Ecology ,02 engineering and technology ,Agricultural engineering ,0915 Interdisciplinary Engineering ,Industrial and Manufacturing Engineering ,CARBON ,Engineering ,Food production ,DESIGN ,Energy forecasting ,SYSTEMS ,0202 electrical engineering, electronic engineering, information engineering ,PART 1 ,GREENHOUSE TOMATO PRODUCTION ,Green & Sustainable Science & Technology ,OPTIMIZATION ,0505 law ,General Environmental Science ,Science & Technology ,Renewable Energy, Sustainability and the Environment ,business.industry ,05 social sciences ,Engineering, Environmental ,Glasshouse operation ,LIFE-CYCLE ,0910 Manufacturing Engineering ,Heated production ,MODEL ,0907 Environmental Engineering ,Greenhouse gas ,Sustainability ,050501 criminology ,Carbon footprint ,Food processing ,Science & Technology - Other Topics ,OPERATION ,Food systems ,Environmental science ,Energy requirements ,business ,Energy source ,Life Sciences & Biomedicine ,Environmental Sciences - Abstract
Quantifying the use of resources in food production and its environmental impact is key to identifying distinctive measures which can be used to develop pathways towards low-carbon food systems. In this paper, a first-principle modelling approach is developed, referred to as gThermaR (Glasshouse-Thermal Requirements). gThermaR is a generic tool that focuses on the energy requirements of protected heated production, by integrating holistic energy, carbon, and cost modelling, food production, data analytics and visualization. The gThermaR tool employs historic data from weather stations, growing schedules and requirements specific to grower and product needs (e.g. set-point temperatures, heating periods, etc.) in order to quantify the heating and cooling requirements of glasshouse food production. In the present paper, a case study is reported that employs a database compiled for the UK. Another relevant feature of the tool is that it can quantify the effects that spatial and annual weather trends can have on these heating and cooling requirements. The main contribution of this work, therefore, concerns the development a tool that can provide a simple integrated approach for performing a wide range of analyses relevant to the thermal requirements of heated glasshouses. The tool is validated through collaborations with industrial partners and showcased in a case study of a heated glasshouse in the UK, offering the capacity to benchmark and compare different glasshouse types and food growth processes. Results from the case study indicate that a significant reduction in the heating requirement and, therefore, carbon footprint, of the facility can be achieved by improving key design and operational parameters. Results indicate savings in the peak daily and annual heating requirements of 44–50% and 51–57% respectively, depending on the region where the glasshouse is located. This improvement is also reflected in the carbon emissions and operating costs for the different energy sources considered. Furthermore, the temporal variability/uncertainty of the annual energy requirements and of the peak daily energy requirements are found to be considerably lowered through improvements to the glasshouse attributes. Overall, gThermaR proves its value in quantifying and identifying key factors that have a significant impact on energy requirements of heated glasshouses. Such valuable outputs are invaluable for stakeholders in the food industry that have an interest in mapping the sustainability and mitigating the carbon footprint of their supply chain processes.
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- 2018
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28. On the fate of oxygenated organic molecules in atmospheric aerosol particles
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Felipe D. Lopez-Hilfiker, André S. H. Prévôt, Liine Heikkinen, I. El Haddad, Urs Baltensperger, Wei Huang, Jay G. Slowik, Josef Dommen, Mao Xiao, Veronika Pospisilova, Claudia Mohr, David M. Bell, and INAR Physics
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,ALPHA-PINENE ,PEROXIDES ,OZONOLYSIS ,010501 environmental sciences ,OXIDATION ,Mass spectrometry ,complex mixtures ,114 Physical sciences ,01 natural sciences ,Organic molecules ,CHEMISTRY ,PARTICULATE MATTER ,ddc:550 ,PART 1 ,Molecule ,AUTOXIDATION ,Research Articles ,0105 earth and related environmental sciences ,Multidisciplinary ,SPECTROMETER EESI-TOF ,Autoxidation ,Chemistry ,Extractive electrospray ionization ,SciAdv r-articles ,MASS-SPECTROMETRY ,respiratory system ,Particulates ,Aerosol ,Earth sciences ,13. Climate action ,Environmental chemistry ,Volatility (chemistry) ,Research Article - Abstract
Real-time investigation of the intraparticle reactions in secondary organic aerosol., Highly oxygenated organic molecules (HOMs) are formed from the oxidation of biogenic and anthropogenic gases and affect Earth’s climate and air quality by their key role in particle formation and growth. While the formation of these molecules in the gas phase has been extensively studied, the complexity of organic aerosol (OA) and lack of suitable measurement techniques have hindered the investigation of their fate post-condensation, although further reactions have been proposed. We report here novel real-time measurements of these species in the particle phase, achieved using our recently developed extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF). Our results reveal that condensed-phase reactions rapidly alter OA composition and the contribution of HOMs to the particle mass. In consequence, the atmospheric fate of HOMs cannot be described solely in terms of volatility, but particle-phase reactions must be considered to describe HOM effects on the overall particle life cycle and global carbon budget.
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- 2020
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29. Quantifying the Contribution of Crystallographic Texture and Grain Morphology on the Elastic and Plastic Anisotropy of bcc Steel
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Enrico Bruder, Martin Diehl, and Jörn Niehuesbernd
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lcsh:TN1-997 ,Technology ,Yield (engineering) ,Materials science ,HOMOGENIZATION ,AUTOMATED-ANALYSIS ,EBSD ,Materials Science ,Modulus ,Materials Science, Multidisciplinary ,anisotropy ,02 engineering and technology ,01 natural sciences ,DEFORMATION ,0103 physical sciences ,PART 1 ,General Materials Science ,Texture (crystalline) ,Representation (mathematics) ,Anisotropy ,lcsh:Mining engineering. Metallurgy ,linear flow splitting ,crystal plasticity ,DAMASK ,texture ,010302 applied physics ,Science & Technology ,STRESS-STRAIN FIELDS ,Orientation (computer vision) ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Microstructure ,SIMULATIONS ,MODEL ,Crystallography ,POLYCRYSTALLINE MICRO STRUCTURES ,ebsd ,damask ,Metallurgy & Metallurgical Engineering ,CONSTRAINED SURFACE MICROSTRUCTURE ,0210 nano-technology ,Electron backscatter diffraction - Abstract
The influence of grain shape and crystallographic orientation on the global and local elastic and plastic behaviour of strongly textured materials is investigated with the help of full-field simulations based on texture data from electron backscatter diffraction (EBSD) measurements. To this end, eight different microstructures are generated from experimental data of a high-strength low-alloy (HSLA) steel processed by linear flow splitting. It is shown that the most significant factor on the global elastic stress−strain response (i.e., Young’s modulus) is the crystallographic texture. Therefore, simple texture-based models and an analytic expression based on the geometric mean to determine the orientation dependent Young’s modulus are able to give accurate predictions. In contrast, with regards to the plastic anisotropy (i.e., yield stress), simple analytic approaches based on the calculation of the Taylor factor, yield different results than full-field microstructure simulations. Moreover, in the case of full-field models, the selected microstructure representation influences the outcome of the simulations. In addition, the full-field simulations, allow to investigate the micro-mechanical fields, which are not readily available from the analytic expressions. As the stress−strain partitioning visible from these fields is the underlying reason for the observed macroscopic behaviour, studying them makes it possible to evaluate the microstructure representations with respect to their capabilities of reproducing experimental results.
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- 2019
30. Wave propagation analysis for a second strain gradient rod theory
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Abdelmalek Zine, Guang Zhu, C. Droz, Mohamed Ichchou, Modélisation mathématique, calcul scientifique (MMCS), Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS)
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Technology ,REFLECTION ,0209 industrial biotechnology ,Work (thermodynamics) ,Energy flow ,TRANSMISSION ,Wave propagation ,MODELS ,Aerospace Engineering ,Wave propagation features ,02 engineering and technology ,Dynamic behavior ,Enriched rod model ,[MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA] ,01 natural sciences ,010305 fluids & plasmas ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Reflection and transmission ,Engineering ,020901 industrial engineering & automation ,Planar ,GRANULAR MATERIAL ,Dispersion relation ,0103 physical sciences ,PART 1 ,[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP] ,Boundary value problem ,Engineering, Aerospace ,ComputingMilieux_MISCELLANEOUS ,Motor vehicles. Aeronautics. Astronautics ,Physics ,[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph] ,Science & Technology ,Continuum mechanics ,Second strain gradient theory ,SURFACES ,Mechanical Engineering ,[SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment ,ELASTICITY ,Mathematical analysis ,TL1-4050 ,BEAMS ,Reflection (physics) ,BEHAVIOR ,Longitudinal wave ,[MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA] - Abstract
International audience; In this work, an enriched model describing the longitudinal wave propagation is established based on Mindlin’s Second Strain Gradient (SSG) theory, which can describe the heterogeneity caused by the micro-structure interactions in the frame of continuum mechanics. The governing equation and associated boundary conditions are derived based on Hamilton's principle, then the dispersion relation of non-classical longitudinal wave together with the extra-waves appearing exclusively in SSG theory model are investigated. The investigations are based on the modal density, energy flow, and forced response of the rod. Wave transmission and reflection through planar interfaces based on the proposed model have been calculated. Finally, the results of the enriched model are well interpreted by comparing with the classical theory results, and some useful conclusions are derived on the SSG theory based model in the wave propagation characterization.
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- 2019
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31. Sea Spray Aerosol Formation: Laboratory Results on the Role of Air Entrainment, Water Temperature, and Phytoplankton Biomass
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Quynh T. Nguyen, Sigurd Christiansen, Matthew Salter, Elena Gorokhova, and Merete Bilde
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010501 environmental sciences ,Atmospheric sciences ,CHEMICAL-COMPOSITION ,01 natural sciences ,Phytoplankton biomass ,OCEAN ,Environmental Chemistry ,PART 1 ,Seawater ,Biomass ,Biological sciences ,0105 earth and related environmental sciences ,PRIMARY MARINE AEROSOL ,Aerosols ,SALT ,Temperature ,Water ,General Chemistry ,Laboratory results ,Sea spray ,THERMOPHYSICAL PROPERTIES ,Aerosol ,BREAKING-WAVE ,ORGANIC-MATTER ,Water temperature ,Scientific method ,Phytoplankton ,GAS ENTRAINMENT ,Environmental science ,Air entrainment ,ENRICHMENT - Abstract
Sea spray aerosol (SSA) emission is a complex process affected by various controlling factors. This work seeks to deconvolute some of this complexity in a controlled laboratory setting using a plunging jet by varying three key parameters, one at a time: (1) air entrainment rate, (2) seawater temperature, and (3) biomass of phytoplankton. The production of SSA is found to vary linearly with air entrainment rate. By normalizing the production flux to air entrainment rate, we observe nonlinear variation of the production efficiency of SSA with seawater temperature with a minimum around 6-10 °C. For comparison, SSA was also generated by detraining air into artificial seawater using a diffuser demonstrating that the production efficiency of SSA generated using a diffuser decreases almost linearly with increasing seawater temperature, and the production efficiency is significantly higher than that for SSA generated using a plunging jet. Finally, by varying the amount of phytoplankton biomass we demonstrate that SSA particle production varies nonlinearly with the amount of biomass in seawater.
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- 2019
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32. Identification and structural analysis of cereal arabinoxylan-derived oligosaccharides by negative ionization HILIC-MS/MS
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Päivi Tuomainen, Markus Kotiranta, Jouni Jokela, Minna Juvonen, Maija Tenkanen, Department of Food and Nutrition, Department of Microbiology, Cyanobacteria research, Carbohydrate Chemistry and Enzymology, and Food Sciences
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Spectrometry, Mass, Electrospray Ionization ,Tandem mass spectrometry ,ASSISTED-LASER-DESORPTION/IONIZATION ,HUMAN-MILK OLIGOSACCHARIDES ,Oligosaccharides ,Glucuronates ,01 natural sciences ,Analytical Chemistry ,Ion ,ION MODE ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Ionization ,Arabinoxylan ,XYLO-OLIGOSACCHARIDES ,Carbohydrate Conformation ,PART 1 ,SPECTRA ,MSN ,UNDERIVATIZED OLIGOSACCHARIDES ,Residue (complex analysis) ,Chromatography ,Hydrophilic interaction chromatography ,010401 analytical chemistry ,04 agricultural and veterinary sciences ,General Medicine ,040401 food science ,0104 chemical sciences ,Hilic ms ms ,chemistry ,416 Food Science ,Xylans ,ELECTROSPRAY MASS-SPECTROMETRY ,LIQUID-CHROMATOGRAPHY ,Edible Grain ,Negative ionization ,Xylooligosaccharide ,Linkage analysis ,Food Science ,Chromatography, Liquid - Abstract
Recent works provide evidence of the prebiotic potential of arabinoxylan-derived oligosaccharides (A)XOS. In this study, we developed a structural analysis for cereal-derived (A)XOS by negative ionization HILIC-MS/MS. Initially, we assessed twelve (A)XOS samples of known structures with different linkage positions and branching points by direct-infusion negative ESI-MSn. We subsequently developed the negative ion HILIC-MS/MS with a post-column addition of ammonium chloride. The selected (A)XOS represented both linear (arabinofuranosyl residue linked to the non-reducing end of xylooligosaccharide) and branched structures. Each (A)XOS sample produced a specific spectrum in negative ion ESI-MSn. By analyzing cross-ring fragment ions, we determined the linkage positions of linear (A)XOS. The presence or absence of diagnostic ions in the MS3 allowed us to detect different branches (O-2- or/and O-3-linked arabinofuranosyl with/or without O-4-linked xylopyranosyl at the non-reducing end). Furthermore, we could identify all analyzed samples by HILIC-MS/MS, based on the formed spectral library and chromatographic retention times.
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- 2019
33. Prediction Methods and Experimental Techniques for Chatter Avoidance in Turning Systems: A Review
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Ingeniería mecánica, Ingeniaritza mekanikoa, Urbicain Pelayo, Gorka, Olvera Trejo, Daniel, López de Lacalle Marcaide, Luis Norberto, Beranoagirre Imaz, Aitor, Elías Zuñiga, Alex, Ingeniería mecánica, Ingeniaritza mekanikoa, Urbicain Pelayo, Gorka, Olvera Trejo, Daniel, López de Lacalle Marcaide, Luis Norberto, Beranoagirre Imaz, Aitor, and Elías Zuñiga, Alex
- Abstract
The general trend towards lightweight components and stronger but difficult to machine materials leads to a higher probability of vibrations in machining systems. Amongst them, chatter vibrations are an old enemy for machinists with the most dramatic cases resulting in machine-tool failure, accelerated tool wear and tool breakage or part rejection due to unacceptable surface finish. To avoid vibrations, process designers tend to command conservative parameters limiting productivity. Among the different machining processes, turning is responsible of a great amount of the chip volume removed worldwide. This paper reports some of the main efforts from the scientific literature to predict stability and to avoid chatter with special emphasis on turning systems. There are different techniques and approaches to reduce and to avoid chatter effects. The objective of the paper is to summarize the current state of research in this hot topic, particularly (1) the mechanistic, analytical, and numerical methods for stability prediction in turning; (2) the available techniques for chatter detection and control; (3) the main active and passive techniques.
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- 2019
34. In vitro hip testing in the International Society of Biomechanics coordinate system
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van Arkel, Richard J., Jeffers, Jonathan R.T., Wellcome Trust, Engineering & Physical Science Research Council (EPSRC), and Engineering and Physical Sciences Research Council
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Models, Anatomic ,Technology ,MOTION ,Short Communication ,Biophysics ,Biomedical Engineering ,CAPSULAR LIGAMENTS ,Engineering ,In vitro ,0903 Biomedical Engineering ,Humans ,PART 1 ,Orthopedics and Sports Medicine ,Range of Motion, Articular ,Reference frame ,ARTHROPLASTY ,POSITION ,Engineering, Biomedical ,1106 Human Movement And Sports Science ,Science & Technology ,Hip ,STABILITY ,JOINT ,RANGE ,Coordinate system ,Rehabilitation ,Bone pots ,CONSTRAINTS ,Biomechanical Phenomena ,Hip Joint ,ACETABULAR LABRUM ,Life Sciences & Biomedicine ,0913 Mechanical Engineering - Abstract
Many innovative experiments are designed to answ er research questions about hip biomechanics, however many fail to define a coordinate system. This makes comparisons between studies unreliable and is an unnecessary hurdle in extrapolating experimental results to clinical reality. The aim of this study was to present a specimen mounting protocol which aligns and registers hip specimens in the International Society of Biomechanics (ISB) coordinate system, which is defined by bony landmarks that are identified by palpation of the patient’s body. This wou ld enable direct comparison between experimental testing and clinical gait analysis or radiographic studies. To represent the intact hip, four intact synthetic full - pelves with 8 full - length articulating femora were assembled and digitised to define the IS B coordinate system. Using our proposed protocol, pelvis specimens were bisected into left and right hemi - pelves and femora transected at the mid - shaft, and then mounted in bone pots to represent a typical experimental setup. Anatomical landmarks were re - digitised relative to mechanical features of the bone pots and the misalignment was calculated. The mean misalignment was found to be less than 1.5° flexion/extension, ab/adduction and internal/external rotation for both the pelves and femora; this equate s to less than 2.5 % of a normal range of hip motion. The proposed specimen mounting protocol provides a simple method to align in vitro hip specimens in the ISB coordinate system which enables improved comparison between laboratory testing and clinical s tudies. Engineering drawings are provided to allow others to replicate the simple fixtures used in the protocol.
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- 2016
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35. Behaviour and design of stainless steel SHS and RHS beam-columns
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Leroy Gardner, Ou Zhao, and Ben Young
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Technology ,Engineering, Civil ,Engineering ,COMBINED AXIAL LOAD ,CONTINUOUS STRENGTH METHOD ,020101 civil engineering ,02 engineering and technology ,Bending ,Mechanics ,Civil Engineering ,0901 Aerospace Engineering ,0905 Civil Engineering ,CROSS-SECTIONS ,0201 civil engineering ,0203 mechanical engineering ,TUBULAR MEMBERS ,PART 1 ,Civil and Structural Engineering ,Science & Technology ,business.industry ,Mechanical Engineering ,Building and Construction ,Structural engineering ,Strain hardening exponent ,Steel square ,Engineering, Mechanical ,Moment (mathematics) ,CIRCULAR HOLLOW SECTIONS ,020303 mechanical engineering & transports ,Buckling ,Bending moment ,STRUCTURAL PERFORMANCE ,COMPRESSION ,Deformation (engineering) ,business ,Beam (structure) ,0913 Mechanical Engineering - Abstract
Previous studies on stainless steel tubular section beam-columns have revealed shortcomings in established codified design methods. These shortcomings stem principally from inaccurate predictions of the bending and column buckling end points of the design interaction curves, where the bending moment end points are tied to the elastic or plastic moment capacities without considering strain hardening, while the column buckling end points are often over-predicted. Inaccuracies also arise due to the adopted interaction factors, which do not fully capture the structural response of the stainless steel members under combined loading. These observations prompted the present research, which is aimed at developing more efficient design rules for stainless steel tubular section beam-columns. In the presented design proposals, the deformation-based continuous strength method (CSM), allowing for strain hardening, was used to determine the bending moment capacities (i.e. the bending end points), while the column buckling strengths (i.e. the column end points) were calculated according to recently proposed buckling curves. Based on these more accurate end points, new interaction factors were derived following a comprehensive numerical simulation programme. The accuracy of the new proposals was assessed through comparisons against over 3000 experimental and numerical results. Compared to the current design standards, the new proposal yields a higher level of accuracy and consistency in the prediction of stainless steel square and rectangular hollow section (SHS and RHS) beam-column strengths. Use of the proposed interaction factors but with the Eurocode bending moment capacities and revised column buckling strengths as the end points was also assessed and shown to result in more accurate and less scattered strength predictions than the current Eurocode provisions. The reliability of the proposals has been confirmed by means of statistical analyses according to EN 1990, demonstrating its suitability for incorporation into future revisions of international design codes for stainless steel structures.
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- 2016
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36. The effect of natural zeolite on microstructure, mechanical and heavy metals adsorption properties of metakaolin based geopolymers
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João Rocha, Alcina Johnson Sudagar, W. Hajjaji, Ana Velosa, Carla Patinha, Fernando Rocha, E. Ferreira da Silva, and Slavka Andrejkovičová
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Materials science ,Sodium silicate ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,THERMAL TRANSFORMATION ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,SI-29 ,Geochemistry and Petrology ,PART 1 ,AL-27 ,Zeolite ,Metakaolin ,0105 earth and related environmental sciences ,Clinoptilolite ,Langmuir adsorption model ,Geology ,KAOLINITE ,021001 nanoscience & nanotechnology ,ALKALI-ACTIVATED BINDERS ,NMR ,ACID ATTACK ,PRODUCTS ,Geopolymer ,Compressive strength ,chemistry ,symbols ,0210 nano-technology ,Nuclear chemistry - Abstract
This work investigates the effect of clinoptilolite, a natural zeolite, as filler on the mechanical performance and heavy metal's adsorption capacity of the metakaolin-based geopolymers. Clinoptilolite was chosen as an inexpensive additive with high adsorption capacity, replacing metakaolin (0, 25, 50 and 75%) in the synthesis of four different geopolymers (MK100, MK75, MK50 and MK25, respectively). To produce geopolymers with low environmental impact, during the geopolymerization processes the SiO2/Al2O3 and Na2O/Al2O3 molar ratios were kept constant at 1, to reduce sodium silicate and sodium hydroxide to a minimum. The final products were studied by powder X-ray diffraction, Al-27 and Si-29 solid-state NMR and Scanning electron microscopy. Moreover, strength parameters and heavy metals Pb2+, Zn2+, Cu2+, Cd2+ and Cr3+ adsorption tests were performed. The results show that geopolymerization in the presence of zeolite leads to an increase of the compressive strength of all blended geopolymers, with an optimal metakaolin precursor/zeolite filler ratio of 50:50, affording the highest strength (8.8 MPa at 28 days). The adsorption of metal cations on geopolymers was well fitted using the Langmuir model (0.97 < R-2 < 0.99). The geopolymers adsorbed heavy metals in the order Pb2+ > Cd2+ > Zn2+, Cu2+ > Cr3+ The maximum adsorption capacity of Cu2+ and Cr3+ was highest for geopolymer with 100% of metakaolin (MK100), while for Pb2+, Cd2+ and Zn2+ the highest adsorption capacity is for geopolymers with 75% of metakaolin (MK75), indicating that 25% zeolite addition to geopolymers has efficiently improved the adsorption capacity. (C) 2016 Elsevier B.V. All rights reserved.
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- 2016
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37. Porous biomass fly ash-based geopolymers with tailored thermal conductivity
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Rui M. Novais, João A. Labrincha, Maria Paula Seabra, L.H. Buruberri, and G. Ascensão
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Materials science ,METAKAOLIN-BASED GEOPOLYMERS ,COST-ANALYSIS ,Strategy and Management ,WASTE ,0211 other engineering and technologies ,ENERGY-CONSUMPTION ,Biomass ,02 engineering and technology ,CHEMICAL-COMPOSITION ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Thermal conductivity ,Thermal insulation ,021105 building & construction ,PART 1 ,RED MUD ,SODIUM-HYDROXIDE ,Hydrogen peroxide ,Porosity ,General Environmental Science ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,Building and Construction ,021001 nanoscience & nanotechnology ,Geopolymer ,chemistry ,Volume (thermodynamics) ,Chemical engineering ,CO2 EMISSIONS ,Fly ash ,MICROSTRUCTURE ,0210 nano-technology ,business - Abstract
In this work novel, porous biomass fly ash-based-geopolymers were produced by using hydrogen peroxide as pore forming agent. This innovative material can help to mitigate the energy losses inside buildings, while simultaneously reducing the volume of generated wastes, thus contributing towards sustainable construction. Results demonstrate that the content of hydrogen peroxide controls the geopolymer physical properties such as porosity, mechanical resistance and thermal conductivity. The latter allows the production of geopolymers displaying suitable properties for thermal insulation applications. Geopolymers exhibiting thermal conductivity as low as 0.107 W/m K and a density of 560 kg/m(3) were produced, showing the potential of these materials in applications requiring lightweight and low thermal conductivity materials. Besides this material is produced using a simple and cost effective approach, promoting waste valorization by reuse of biomass fly ash, which further demonstrates its potential. (C) 2016 Elsevier Ltd. All rights reserved.
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- 2016
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38. Discriminant validity of 3D joint kinematics and centre of mass displacement measured by inertial sensor technology during the unipodal stance task
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J Malcorps, Mariska Wesseling, L. De Baets, Benedicte Vanwanseele, Johan Bellemans, Amber K B D Bruijnes, R. van der Straaten, Jan Truijen, Annick Timmermans, Ilse Jonkers, Malcorps, Jan, Jonkers, Ilse, Wesslink, Mariska, VAN DER STRAATEN, Rob, BELLEMANS, Johan, Van Wanseele, Benedicte, BRUIJNES, Amber, TRUIJEN, Jan, DE BAETS, Liesbet, TIMMERMANS, Annick, Vesalius College, and Physiotherapy, Human Physiology and Anatomy
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Male ,System ,Kinematics ,Knee Joint ,Inertia ,Measurement Units ,Knees ,Knee Joints ,Part 1 ,02 engineering and technology ,Osteoarthritis ,medicine.disease_cause ,Weight-bearing ,0302 clinical medicine ,Skeletal Joints ,Validation ,Medicine and Health Sciences ,Prevalence ,Risk-Factors ,Range of Motion, Articular ,Postural Balance ,Musculoskeletal System ,Multidisciplinary ,Osteoarthritis, Knee/physiopathology ,Physics ,Classical Mechanics ,Osteoarthritis, Knee ,Middle Aged ,Sensory Systems ,Biomechanical Phenomena ,Lower Extremity ,Knee Joint/physiology ,Physical Sciences ,Limitations ,Legs ,Medicine ,Female ,Anatomy ,Lower Extremity/physiology ,Research Article ,musculoskeletal diseases ,Postural Balance/physiology ,Range of Motion, Articular/physiology ,medicine.medical_specialty ,Science ,0206 medical engineering ,Case-control studies ,Statistical parametric mapping ,Pelvis ,Motion ,03 medical and health sciences ,Imaging, Three-Dimensional ,Physical medicine and rehabilitation ,medicine ,Humans ,Displacement (orthopedic surgery) ,Aged ,030203 arthritis & rheumatology ,Hip ,business.industry ,Discriminant validity ,Biology and Life Sciences ,Construct validity ,medicine.disease ,020601 biomedical engineering ,Trunk ,Body Limbs ,Remote Sensing Technology ,Reported Knee Instability ,reproducibility of results ,business ,Neuroscience - Abstract
BackgroundThe unipodal stance task is a clinical task that quantifies postural stability and alignment of the lower limb joints, while weight bearing on one leg. As persons with knee osteoarthritis (KOA) have poor postural and knee joint stability, objective assessment of this task might be useful.ObjectiveTo investigate the discriminant validity of three-dimensional joint kinematics and centre of mass displacement (COM) between healthy controls and persons with knee KOA, during unipodal stance using inertial sensors. Additionally, the reliability, agreement and construct validity are assessed to determine the reproducibility and accuracy of the discriminating parameters.MethodsTwenty healthy controls and 19 persons with unilateral severe KOA were included. Five repetitions of the unipodal stance task were simultaneously recorded by an inertial sensor system and a camera-based system (gold standard). Statistical significant differences in kinematic waveforms between healthy controls and persons with severe knee KOA were determined using one-dimensional statistical parametric mapping (SPM1D).ResultsPersons with severe knee KOA had more lateral trunk lean towards the contralateral leg, more hip flexion throughout the performance of the unipodal stance task, more pelvic obliquity and COM displacement towards the contralateral side. However, for the latter two parameters the minimum detectable change was greater than the difference between healthy controls and persons with severe knee KOA. The construct validity was good (coefficient of multiple correlation 0.75, 0.83 respectively) and the root mean squared error (RMSE) was low (RMSE
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- 2020
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39. Spontaneous realigning of a displaced equine premolar post extraction of an adjacent supernumerary tooth - two cases = Spontane repositie van een equiene premolaar na extractie van eenaanpalende polydonte tand – twee casussen
- Author
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Pollaris, Elke, Vanderperren, Katrien, De Pauw, Guy, and Vlaminck, Lieven
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stomatognathic diseases ,TEETH ,stomatognathic system ,LONG-TERM ,DISORDERS ,ORAL-EXTRACTION ,POLYODONTIA ,PART 1 ,Veterinary Sciences ,CHEEK TOOTH ,POSITION ,ROOT RESORPTION ,ORTHODONTICS - Abstract
Two horses were presented with problems during ridden exercise due to a firm, sensitive swelling at the level of the cheek adjacent to an upper Triadan 06. Oral, radiographic and computed tomographic examinations (n=1) identified the presence of a palatal supernumerary tooth being the causing factor of a buccally displaced 06. In both cases, the supernumerary tooth was extracted on the standing sedated horse. A couple of months following extraction, the buccally displaced tooth had spontaneously moved into a more physiological position due to orthodontic forces of the cheek and masticatory forces. Both horses uneventfully returned to ridden work without further problems.
- Published
- 2019
40. Extensive Soot Compaction by Cloud Processing from Laboratory and Field Observations
- Author
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Paulo Fialho, Giulia Pavese, Maria Cristina Facchini, Janarjan Bhandari, Timothy B. Onasch, Manvendra K. Dubey, Will Cantrell, Raymond A. Shaw, Greg Kinney, Stefania Gilardoni, Kyle Gorkowski, Swarup China, Rajan K. Chakrabarty, Francesco Esposito, Allison C. Aiken, Kamal Kant Chandrakar, Barbara V. Scarnato, Claudio Mazzoleni, Hans Moosmüller, Rahul A. Zaveri, Noopur Sharma, Nicola Zanca, Stefano Decesari, Lynn Mazzoleni, Giulia Girotto, Department, Institute for Atmospheric and Earth System Research (INAR), and Department of Chemistry
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Materials science ,010504 meteorology & atmospheric sciences ,Field (physics) ,DROPLET ACTIVATION ,116 Chemical sciences ,Compaction ,Evaporation ,lcsh:Medicine ,BLACK CARBON PARTICLES ,010501 environmental sciences ,Combustion ,medicine.disease_cause ,01 natural sciences ,114 Physical sciences ,soot ,Article ,FRACTAL DIMENSION ,AEROSOL LIGHT-ABSORPTION ,morphology ,Radiative transfer ,medicine ,Atmospheric science ,Climate change ,Cloud condensation nuclei ,PART 1 ,cloud ,lcsh:Science ,Air quality index ,ORGANIC-COMPOUNDS ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Multidisciplinary ,electron microscopy ,MIXING STATE ,lcsh:R ,aging ,cloud computing ,humidity ,OPTICAL-PROPERTIES ,Soot ,SIZE ,Chemical engineering ,13. Climate action ,lcsh:Q - Abstract
Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after evaporating the cloud droplets, are significantly more compact than freshly emitted and interstitial soot, confirming that cloud processing, not just exposure to high humidity, compacts soot. Our findings have implications for how the radiative, surface, and aerodynamic properties, and the fate of soot particles are represented in numerical models.
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- 2019
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41. Standardised material properties for numerical parametric studies of stainless steel structures and buckling curves for tubular columns
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Leroy Gardner, Sheida Afshan, Ou Zhao, School of Civil and Environmental Engineering, and Commission of the European Communities
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Technology ,Engineering, Civil ,Materials science ,Parametric study ,Civil Engineering ,0905 Civil Engineering ,Stainless steel ,Engineering ,DESIGN ,Ultimate tensile strength ,PART 1 ,Civil and Structural Engineering ,Parametric statistics ,Material modelling ,Austenite ,HOLLOW SECTIONS ,Science & Technology ,Buckling Curves ,Civil engineering [Engineering] ,business.industry ,Metals and Alloys ,Buckling curves ,Building and Construction ,Structural engineering ,Compression (physics) ,Reliability ,Steel square ,Columns ,Buckling ,Mechanics of Materials ,TESTS ,Construction & Building Technology ,STRESS-STRAIN CURVES ,STRENGTH ENHANCEMENTS ,COMPRESSION ,Material properties ,business ,MEMBERS ,BEHAVIOR ,RESISTANCE ,Test data - Abstract
While the nominal material properties given in material specifications are suitable for design purposes, for the generation of realistic numerical parametric results that are ‘equivalent’ to physical experiments, material properties that are representative of actual structural members are required. Standardised values for these properties are proposed herein. Following analysis of a comprehensive database of material test data from different stainless steel products, values for the yield stress fy, the ultimate tensile stress fu, the strain at ultimate tensile stress εu and the Ramberg-Osgood parameters n and m are proposed. This enables the generation of standardised stress-strain curves for typical austenitic, duplex and ferritic stainless steel sections. Following this, an extensive numerical modelling study, incorporating the proposed standardised material parameters, was carried out to investigate the effect of production route (cold-formed and hot-finished) and material grade (austenitic, duplex and ferritic) on the flexural buckling behaviour and design of stainless steel square, rectangular and circular hollow section compression members. The FE generated flexural buckling data, combined with column test data from the literature, were used to derive a series of buckling curves for the design of stainless steel compression members. The suitability of the proposals was confirmed by means of reliability analysis.
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- 2019
42. Prediction Methods and Experimental Techniques for Chatter Avoidance in Turning Systems: A Review
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Gorka Urbikain, L.N. López de Lacalle, Daniel Olvera, Alex Elías-Zúñiga, and A. Beranoagirre
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chatter ,0209 industrial biotechnology ,Process (engineering) ,Computer science ,Stability (learning theory) ,02 engineering and technology ,stability analysis ,lcsh:Technology ,part 1 ,lcsh:Chemistry ,vibrations ,020901 industrial engineering & automation ,Machining ,regenerative chatter ,Prediction methods ,General Materials Science ,turning ,Tool wear ,lcsh:QH301-705.5 ,Instrumentation ,spindle speed variation ,Fluid Flow and Transfer Processes ,flexible workpiece ,lcsh:T ,Process Chemistry and Technology ,General Engineering ,machine-tool chatter ,lathe tools ,Limiting ,dynamics ,stability ,021001 nanoscience & nanotechnology ,lcsh:QC1-999 ,Computer Science Applications ,Reliability engineering ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,boring operations ,vibration ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,lcsh:Physics - Abstract
The general trend towards lightweight components and stronger but difficult to machine materials leads to a higher probability of vibrations in machining systems. Amongst them, chatter vibrations are an old enemy for machinists with the most dramatic cases resulting in machine-tool failure, accelerated tool wear and tool breakage or part rejection due to unacceptable surface finish. To avoid vibrations, process designers tend to command conservative parameters limiting productivity. Among the different machining processes, turning is responsible of a great amount of the chip volume removed worldwide. This paper reports some of the main efforts from the scientific literature to predict stability and to avoid chatter with special emphasis on turning systems. There are different techniques and approaches to reduce and to avoid chatter effects. The objective of the paper is to summarize the current state of research in this hot topic, particularly (1) the mechanistic, analytical, and numerical methods for stability prediction in turning; (2) the available techniques for chatter detection and control; (3) the main active and passive techniques. Thanks are addressed to Basque country university excellence group IT1337-19. The authors wish to acknowledge also the financial support received from HAZITEK program, from the Department of Economic Development and Infrastructures of the Basque Government and from FEDER funds. This research was funded by Tecnologico de Monterrey through the Research Group of Nanotechnology for Devices Design, and by the Consejo Nacional de Ciencia y Tecnologia (CONACYT), Project Numbers 242269, 255837, 296176, and the National Lab in Additive Manufacturing, 3D Digitizing and Computed Tomography (MADiT) LN299129.
- Published
- 2019
43. Validation of a model-based inverse kinematics approach based on wearable inertial sensors
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Tagliapietra, L., Modenese, L., Ceseracciu, E., Mazzà, C., and Reggiani, M.
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Technology ,Inertial frame of reference ,Computer science ,inverse kinematics ,GAIT ANALYSIS ,02 engineering and technology ,Kinematics ,Engineering ,0302 clinical medicine ,0903 Biomedical Engineering ,Computer vision ,POSITION ,Range of Motion, Articular ,CALIBRATION PROCEDURE ,Noise (signal processing) ,General Medicine ,IMU ,Computer Science Applications ,Biomechanical Phenomena ,HUMAN MOVEMENT ,Computer Science, Interdisciplinary Applications ,Computer Vision and Pattern Recognition ,LOWER-LIMB ,KNEE KINEMATICS ,0206 medical engineering ,Biomedical Engineering ,JOINT COORDINATE SYSTEM ,1105 Dentistry ,Bioengineering ,global optimization ,Inertial and magnetic measurement units ,joint kinematics ,OpenSim ,Human-Computer Interaction ,Computer Science::Robotics ,03 medical and health sciences ,Motion ,Wearable Electronic Devices ,Position (vector) ,Robustness (computer science) ,Inertial measurement unit ,PART 1 ,Humans ,OPTIMIZATION ,Engineering, Biomedical ,Science & Technology ,Inverse kinematics ,business.industry ,Reproducibility of Results ,030229 sport sciences ,Models, Theoretical ,020601 biomedical engineering ,Computer Science ,Robot ,Artificial intelligence ,ORIENTATION ,business - Abstract
Wearable inertial measurement units (IMUs) are a promising solution to human motion estimation. Using IMUs 3D orientations, a model-driven inverse kinematics methodology to estimate joint angles is presented. Estimated joint angles were validated against encoder-measured kinematics (robot) and against marker-based kinematics (passive mechanism). Results are promising, with RMS angular errors respectively lower than 3 and 6 deg over a minimum range of motion of 50 deg (robot) and 160 deg (passive mechanism). Moreover, a noise robustness analysis revealed that the model-driven approach reduces the effects of experimental noises, making the proposed technique particularly suitable for application in human motion analysis.
- Published
- 2018
44. Multi-site evaluation of the JULES land surface model using global and local data
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Darren Slevin, Simon F. B. Tett, and Mathew Williams
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ENVIRONMENT SIMULATOR JULES ,CLIMATE-CHANGE ,NET ECOSYSTEM EXCHANGE ,Phenology ,lcsh:QE1-996.5 ,Climate change ,WATER FLUXES ,Forcing (mathematics) ,Data set ,lcsh:Geology ,CARBON-DIOXIDE ,FluxNet ,VEGETATION MODELS ,Climatology ,Environmental science ,PART 1 ,Climate model ,Satellite ,ENERGY-BALANCE ,Leaf area index ,ELEVATED CO2 ,TERRESTRIAL BIOSPHERE - Abstract
Changes in atmospheric carbon dioxide and water vapour change the energy balance of the atmosphere and thus climate. One important influence on these greenhouse gases is the land surface. Land Surface Models (LSMs) represent the interaction between the atmosphere and terrestrial biosphere in Global Climate Models (GCMs). As LSMs become more advanced, there is a need to test their accuracy. Uncertainty from LSMs contributes towards uncertainty in carbon cycle simulations and thus uncertainty in future climate change. In this study, we evaluate the ability of the JULES LSM to simulate photosynthesis using local and global datasets at 12 FLUXNET sites. Model parameters include site-specific (local) values for each flux tower site and the default parameters used in the Hadley Centre Global Environmental Model (HadGEM) climate model. Firstly, we compare Gross Primary Productivity (GPP) estimates from driving JULES with data derived from local site measurements with driving JULES with data derived from global parameter and atmospheric reanalysis (on scales of 100 km or so). We find that when using local data, a negative bias is introduced into model simulations with yearly GPP underestimated by 16% on average compared to observations while when using global data, model performance decreases further with yearly GPP underestimated by 30% on average. Secondly, we drive the model using global meteorological data and local parameters and find that global data can be used in place of FLUXNET data with only a 7% reduction in total annual simulated GPP. Thirdly, we compare the global meteorological datasets, WFDEI and PRINCETON, to local data and find that the WATCH dataset more closely matches the local meteorological measurements (FLUXNET). Finally, we compare the results from forcing JULES with the remote sensing product MODIS Leaf Area Index (LAI). JULES was modified to accept MODIS LAI at daily timesteps. We show that forcing the model with daily satellite LAI results in only small improvements in predicted GPP at a small number of sites compared to using the default phenology model.
- Published
- 2018
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45. A 5-year randomized clinical trial comparing minimally with moderately rough implants in patients with severe periodontitis
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Magalie Raes, Marc Quirynen, Wim Teughels, Rutger Dhondt, and Wim Coucke
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Male ,Peri-implantitis ,Alveolar Bone Loss ,Dentistry ,02 engineering and technology ,SURFACE-ROUGHNESS ,Polymerase Chain Reaction ,law.invention ,0302 clinical medicine ,Randomized controlled trial ,law ,Medicine ,IN-VIVO ,surface characteristics ,Jaw, Edentulous, Partially ,Dental Implantation, Endosseous ,Attachment level ,Middle Aged ,PERI-IMPLANTITIS ,Treatment Outcome ,implant failures ,Periodontics ,Female ,PARTIALLY EDENTULOUS PATIENTS ,medicine.symptom ,Periodontal Index ,Life Sciences & Biomedicine ,Surface Properties ,0206 medical engineering ,Bleeding on probing ,Cumulative Survival Rate ,implant surface roughness ,Severe periodontitis ,03 medical and health sciences ,bone loss ,PORPHYROMONAS-GINGIVALIS ,Dentistry, Oral Surgery & Medicine ,PART 1 ,Humans ,Jaw, Edentulous ,In patient ,Periodontitis ,Aged ,Dental Implants ,Science & Technology ,business.industry ,OSSEOINTEGRATED IMPLANTS ,030206 dentistry ,TITANIUM IMPLANTS ,020601 biomedical engineering ,Dental Prosthesis Design ,SUBGINGIVAL PLAQUE ,business ,FOLLOW-UP - Abstract
AIM: To compare the clinical and microbiological performance of minimally and moderately rough implants in patients with a history of severe periodontitis. MATERIAL AND METHODS: Forty-eight minimally (Turned surface [Tur]) and moderately (TiUnite surface [TiU]) rough implants were placed in eighteen patients according to a split-mouth protocol. Marginal bone loss, probing pocket depth (PPD), clinical attachment level (CAL), and bleeding on probing (BoP) were recorded, and microbial samples were analysed by means of quantitative PCR. RESULTS: The amount of bone loss over the 5-year period tended to be lower along Tur when compared with that of TiU surfaces (1.0 versus 1.7 mm, p = .06). Although the clinical outcomes tended to be better for Tur surfaces, there were no significant differences between both surfaces in mean PPD (Tur: 3.1 versus TiU: 4.2 mm, p = .09) or CAL (Tur: 0.5 versus TiU: 1.7 mm, p = .06). More bone loss and deeper pockets were recorded for partially than for fully edentulous patients. The cumulative survival rate at 5-year follow-up was 95.8% for Tur, and 100% for TiU surface implants. No significant differences were found between the surfaces in counts for key pathogens. CONCLUSION: In patients with a history of severe periodontitis minimally rough implants showed more favourable clinical parameters after 5 years of loading, when compared with moderately rough implants. ispartof: JOURNAL OF CLINICAL PERIODONTOLOGY vol:45 issue:6 pages:711-720 ispartof: location:United States status: published
- Published
- 2018
46. A retrospective intercenter comparison of two surgical protocols through the dental arch relationship of 5- to 6-year-old unilateral cleft patients
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Laurent A M Thierens, Guy De Pauw, Noëmi M C De Roo, Liesbeth Temmerman, Guy Willems, Maria Cadenas de Llano Perula, Arianne Lewyllie, and An Verdonck
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Male ,Intraclass correlation ,Overjet ,5-YEAR-OLD CHILDREN ,Dental Occlusion ,0302 clinical medicine ,Cleft lip and palate ,Occlusion ,Child ,INDEX ,Orthodontics ,OUTCOMES ,Modified Huddart ,Plaster Casts ,Models, Dental ,Cleft Palate ,HUDDART/BODENHAM SCORING SYSTEM ,medicine.anatomical_structure ,Treatment Outcome ,Equivalence Trial ,030220 oncology & carcinogenesis ,Child, Preschool ,Female ,Early treatment outcome ,Life Sciences & Biomedicine ,CARE UK ,Cleft Lip ,GOSLON YARDSTICK ,Overbite ,Bodenham scoring system ,03 medical and health sciences ,Dental Arch ,Dentistry, Oral Surgery & Medicine ,medicine ,PART 1 ,Humans ,5-Year-Olds' Index ,General Dentistry ,Retrospective Studies ,Science & Technology ,business.industry ,Reproducibility of Results ,030206 dentistry ,medicine.disease ,LIP ,Sagittal plane ,Dental arch ,PALATE ,business - Abstract
OBJECTIVES: The objectives of this retrospective equivalence trial were to assess the dental arch relationship of 5- to 6-year-old patients with unilateral cleft lip and palate (UCLP) treated in two specialized cleft centers with a different surgical protocol using the 5-Year-Olds' Index and the modified Huddart/Bodenham scoring system, and to determine the correlation between these two scoring indices. MATERIALS AND METHODS: The dental arch relationship of seventy-three 5- to 6-year-old patients with complete UCLP was evaluated on plaster casts using the 5-Year-Olds' Index and the modified Huddart/Bodenham scoring system. The sagittal occlusion, overbite, and overjet were also recorded. Inter- and intra-examiner agreement was determined using Intraclass Correlation Coefficients. RESULTS: A good to very good inter- and intra-examiner agreement was found. No significant mean difference in outcome based on the 5-Year-Olds' Index, the modified Huddart/Bodenham scoring system, overjet, or overbite was detected. For mean difference in sagittal occlusion, the hypothesis that both centers are clinically equivalent was confirmed. A strong negative correlation (rs = - 0.832) between the 5-Year-Olds' Index and the modified Huddart/Bodenham scoring system was found. CONCLUSIONS: The dental arch relationship of 5- to 6-year-old unilateral cleft patients treated in two Belgian cleft centers is clinically equivalent based on sagittal occlusion, despite substantial differences in their treatment protocol. Clinical equivalence for other parameters was not confirmed. There is a strong correlation between the 5-Year-Olds' Index and the modified Huddart/Bodenham scoring system. CLINICAL RELEVANCE: A well-implemented treatment protocol for cleft patients is of the utmost importance, but case load and skill of the surgeon are also important factors for the quality of the results. ispartof: CLINICAL ORAL INVESTIGATIONS vol:23 issue:4 pages:1777-1784 ispartof: location:Germany status: published
- Published
- 2018
47. Immunologic, reproductive, and carcinogenic risk assessment from POP exposure in East Greenland polar bears (Ursus maritimus) during 1983-2013
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Jean-Pierre Desforges, Christian Sonne, Erik W. Born, Frank Rigét, Robert J. Letcher, Kim Gustavson, and Rune Dietz
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Critical body residue ,Reproductive toxicity ,CONTAMINANT TRENDS ,010504 meteorology & atmospheric sciences ,Ursus maritimus ,Population ,Zoology ,Context (language use) ,Organohalogen contaminants ,010501 environmental sciences ,Biology ,01 natural sciences ,Risk Assessment ,POLYCHLORINATED-BIPHENYLS ,biology.animal ,Immune suppression ,PART 1 ,Animals ,PERSISTENT ORGANIC POLLUTANTS ,education ,lcsh:Environmental sciences ,SUPPRESSION ,0105 earth and related environmental sciences ,General Environmental Science ,Trophic level ,lcsh:GE1-350 ,education.field_of_study ,CLIMATE-CHANGE ,Environmental exposure ,Environmental Exposure ,Polar bear ,PERFLUORINATED COMPOUNDS ,TEMPORAL TRENDS ,Arctic ,PBPK modelling ,Risk quotient ,BALTIC SEA ,Environmental Pollutants ,Risk assessment ,RESISTANCE ,Ursidae - Abstract
Polar bears (Ursus maritimus) are among the world's highest trophic level marine predators and as such have some of the highest tissue concentrations of organohalogen contaminants (OHCs) among Arctic biota. In this paper we present the results of a three decade (1983–2013) risk assessment of OHC exposure and effects on reproduction, immunity, and cancer (genotoxicity) in polar bears from Central East Greenland. Risk of adverse effects are evaluated using a risk quotient (RQ) approach with derivation from measured OHC concentrations in polar bear tissue and critical body residues (CBR) extrapolated for polar bears using physiologically-based pharmacokinetic modelling (PBPK). The additive RQs for all OHCs in polar bears were above the threshold for all effect categories (RQ > 1) in every year, suggesting this population has been at significant and continuous risk of contaminant-mediated effects for over three decades. RQs peaked in 1983 (RQ > 58) and again in 2013 (RQ > 50) after a period of decline. These trends follow ΣPCB levels during that time, and contributed almost all of the risk to immune, reproductive, and carcinogenic effects (71–99% of total RQ). The recent spike in RQs suggests a major shift in polar bear contaminant exposure from climate related changes in food composition and hereby the increased risk of adverse health effects. In the context of lifetime exposure ΣPCB and PFOS levels showed the interactive importance of year of birth, age, and emission history. In conclusion, the results indicate that East Greenland polar bears have been exposed to OHC levels over the period of 1983–2013 that potentially and continuously affected individual and theoretically also population health, with a peaking risk in the more recent years. Keywords: Polar bear, Ursus maritimus, Organohalogen contaminants, PBPK modelling, Critical body residue, Immune suppression, Reproductive toxicity, Risk quotient
- Published
- 2018
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48. Diagnosing hydrological limitations of a land surface model: application of JULES to a deep-groundwater chalk basin
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Adrian P. Butler, N. Le Vine, Christopher R. Jackson, and Neil McIntyre
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ENVIRONMENT SIMULATOR JULES ,Environmental Engineering ,0208 environmental biotechnology ,Drainage basin ,UNSATURATED ZONE ,02 engineering and technology ,lcsh:Technology ,0905 Civil Engineering ,lcsh:TD1-1066 ,Water balance ,Hydrology (agriculture) ,Vadose zone ,PART 1 ,WATER ,UK ,Geosciences, Multidisciplinary ,lcsh:Environmental technology. Sanitary engineering ,Water cycle ,RAINFALL-RUNOFF MODEL ,lcsh:Environmental sciences ,lcsh:GE1-350 ,Hydrology ,geography ,Science & Technology ,geography.geographical_feature_category ,lcsh:T ,lcsh:Geography. Anthropology. Recreation ,Geology ,Groundwater recharge ,SOLUTE TRANSPORT ,020801 environmental engineering ,CLIMATE ,Water resources ,0907 Environmental Engineering ,lcsh:G ,Physical Sciences ,Water Resources ,RECHARGE ,SYSTEM ,Groundwater ,0406 Physical Geography And Environmental Geoscience - Abstract
Land surface models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy, and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation and improvement is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution, and spatial water redistribution over the catchment's groundwater and surface-water systems. Three types of information are utilized to improve the model's hydrology: (a) observations, (b) information about expected response from regionalized data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.
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- 2016
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49. On the determination of local residual stress gradients by the slit milling method
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Diego Martinez-Martinez, Vaclav Ocelik, C. Mansilla, and J.Th.M. De Hosson
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COATINGS ,Digital image correlation ,Materials science ,business.industry ,Mechanical Engineering ,Linear elasticity ,Bending ,Residual ,Finite element method ,eye diseases ,Stress (mechanics) ,DIGITAL IMAGE CORRELATION ,Optics ,THIN-FILMS ,Materials Science(all) ,RESOLUTION ,Mechanics of Materials ,Residual stress ,Stress relaxation ,PART 1 ,General Materials Science ,sense organs ,FOCUSED ION-BEAM ,business - Abstract
This paper concentrates on an extension of a rather new methodology to determine local residual gradients at an enhanced lateral resolution using the so-called slit milling technique. The method is based on stress relaxation by making a slit using a focused ion beam and the displacements are measured through digital image correlation so as to calculate the residual stress. Our novel approach consists of a multiple fitting procedure along the length of the slit instead of the commonly applied averaging method. The applicability of our approach is demonstrated when stress gradients exist. In accordance to the Saint-Venant principle in linear elasticity, longer slits are better than shorter slits because of end effects. The proof-of-principle is supported by measurements on steel under controlled bending and by finite element modeling.
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- 2015
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50. Simulating the fluid forces and fluid-elastic instabilities of a clamped–clamped cylinder in turbulent axial flow
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Katrien Van Tichelen, Paul Schuurmans, Jan Vierendeels, Joris Degroote, Jeroen De Ridder, Olivier Doaré, UNIV DE GAND, Unité de Mécanique (UME), École Nationale Supérieure de Techniques Avancées (ENSTA Paris), Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Centre d'Etude de l'Energie Nucléaire (SCK-CEN), Universiteit Gent = Ghent University (UGENT), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D)
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Technology and Engineering ,axial flow ,Water flow ,fluid-structure interaction ,Numerical simulation ,Flow-induced vibrations ,[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] ,Cylinder (engine) ,law.invention ,Physics::Fluid Dynamics ,VISCOUS FLUIDS ,Axial flow ,flow-induced vibrations ,law ,FLEXIBLE CYLINDERS ,Fluid-structure interaction ,Fluid–structure interaction ,PART 1 ,Potential flow around a circular cylinder ,EQUATIONS ,Physics ,CANTILEVERED CYLINDERS ,Turbulence ,Mechanical Engineering ,NONLINEAR DYNAMICS ,Mechanics ,eigenmode ,Classical mechanics ,Axial compressor ,ENDS ,Flow (mathematics) ,Flow velocity ,[SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph] ,numerical simulation ,Eigenmode - Abstract
International audience; In this article, the fluid forces and the dynamics of a flexible clamped-clamped cylinder in turbulent axial flow are computed numerically. In the presented numerical model, there is no need to tune parameters for each specific case or to obtain coefficients from experiments. The results are compared with the dynamics measured in experiments available in literature. The specific case studied here consists of a silicone cylinder mounted in axial water flow. Computationally it is found that the cylinder loses stability first by buckling. The threshold for buckling is in quantitative agreement with experimental results and weakly-nonlinear theory. At higher flow speed a fluttering motion is predicted, in agreement with experimental results. It is also shown that even a small misalignment between the flow and the structure can have a significant impact on the dynamical behavior. To provide insight in the results of these fluid-structure interaction simulations, forces are computed on rigid inclined and curved cylinders, showing the existence of two different flow regimes. Furthermore it is shown that the inlet turbulence state has a non-negligible effect on these forces and thus on the dynamics of the cylinder.
- Published
- 2015
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