Search

Thermal diffusivity is an essential thermophysical factor for designing thermal protection materials. At present, the laser flash method is widely employed for measuring thermal diffusivity, and reasonable determination of experimental parameters is a prerequisite for accurate measurement. In this paper, high-purity graphite is used as the reference specimen, and measurement temperature ranges from 25 °C to 1500 °C. Besides, experimental investigations on the influence of the laser flash method such as specimen thickness, laser pulse energy, and temperature increase rate on the measurement of thermal diffusivity for high-purity graphite are carried out. The results indicate that for high-purity graphite samples, a sample thickness of 3 mm is more appropriate. Additionally, the setting of laser pulse voltage and width is related to the measurement temperature, and the measurement results are more easily affected by the laser pulse width. When measuring temperatures below 600 °C, it is necessary to set both the laser pulse width and voltage to the smallest possible values, provided that a stable signal can be collected. When the temperature is above 600 °C, the laser pulse voltage does not affect the measurement results, but the influence of laser pulse width still needs to be considered to a certain extent. It is only when the measured temperature exceeds 900 °C that neither the laser pulse voltage nor the laser pulse width influences the measurement results. Furthermore, the temperature increase rate has a relatively small impact on the measurement results and can be adjusted according to the measured temperature. The research results can provide a basis for the calibration of experimental parameters in the high-temperature flash method measuring instrument. [ABSTRACT FROM AUTHOR]

Based on the laser flash method, the selection of experimental parameters on the accuracy of measurement results for measuring thermal diffusivity is investigated in this paper. High purity graphite is employed as the experimental material. Three experimental parameters are taken into consideration, including specimen thickness, laser pulse power, and laser pulse width. Firstly, the principle of the laser flash method is introduced. Then, a numerical simulation model is established and independence tests are performed. In order to investigate the impact of different experimental parameters to the precision of the measurement results using the laser flash method, six thicknesses of the specimens, five laser pulse powers, and five laser pulse widths are selected for numerical simulation and LFA 427 measurement experiments. Finally, an orthogonal design method with three-factor and three-level is constructed to investigate the influence degree of these three factors on the measurement results. It is found that the laser pulse width has the most significant influence, while the laser pulse power has the least impact. For high purity graphite specimens, it is required to choose a thicker specimen, a lower laser pulse power, and a smaller laser pulse width to ensure better measurement accuracy. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the synthesis of iron oxide nanoparticles under two different conditions, namely high and low gas flow rates, using laser pyrolysis and to examine the influence of laser power. The attained nanoparticles have been characterised regarding their stability and hydrodynamic dimensions by dispersive light scattering analysis (DLS), structure–X-ray diffraction (XRD), elemental composition–energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and morpho-structural characterisation achieved by transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). For a better understanding of the laser power influence, the residence time was also calculated. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the synthesis of iron oxide nanoparticles under two different conditions, namely high and low gas flow rates, using laser pyrolysis and to examine the influence of laser power. The attained nanoparticles have been characterised regarding their stability and hydrodynamic dimensions by dispersive light scattering analysis (DLS), structure–X-ray diffraction (XRD), elemental composition–energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and morpho-structural characterisation achieved by transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). For a better understanding of the laser power influence, the residence time was also calculated.

This study proposes and applies a systematic data analysis methodology to analyse experimental data for high-performance concrete (HPC) samples with different admixtures for offshore fan foundation grouting materials uses. In contrast with other relevant research, including experimental studies, the materials physics and chemistry studies, or cementitious material portfolio determination studies, this data-driven analysis provides a deep exploration of the experimental variables associated with the test data. To offer complete and in-depth perspectives, several methods are employed for the data analyses, including correlation analysis, cosine similarity analysis, simple linear regression (SLR) modelling, and heat map and heat-based tabularised visualisations; the outcome is a proposed methodology that is easily implementable. The results from these methods are validated using a pairwise comparison approach (PCA) to avoid unnecessary interference between data variables. There are several potential contributions from this work, including insights for cohered groups of variables, techniques for double check and 'third check', an established 'knowledge base' consisting of 504 SLR predictive models with their effectiveness (significance) and prediction accuracy (data-model fitness) used in practical applications, an alternative visualisations of the results, three data transforms which can be omitted in a future analysis, and three valuable theory-linking perspectives (e.g., for the relationships between destructive and non-destructive tests with respect to the variable categories). The implication that some variables are interchangeable will make future experiments less labour intensive and time consuming for pre-project HPC material testing. [ABSTRACT FROM AUTHOR]

Ice adhesion behavior plays a crucial role in assessing ice-phobic materials. However, the variation of ice-adhesion strength across different laboratories is attributed to the neglect of ice/substrate characteristics. In this work, ice-adhesion strength under different geometric parameters of ice/substrate on asphalt surfaces was examined through an optimized methodology. Additionally, a theoretical model was developed based on the energy balance principle to analyze the influence of various parameters on ice-adhesion strength and to make predictions. The results suggested that the ice-adhesion strength was positively correlated with the substrate thickness and negatively correlated with both the asphalt thickness and the ice diameter. The detachment process of the ice-asphalt interface was divided into two regions, the non-linear mechanical response region, and the linear damage region. The slope of the linear damage region can be defined as the interfacial stiffness of the ice-asphalt system, which was the main reason leading to the change in ice adhesion strength. The increase in ice-adhesion strength was observed as the interfacial stiffness increased. Moreover, the theoretical model of ice-adhesion strength illustrated the effect of ice/substrate geometric characteristics on ice-adhesion strength and was verified by the experiments. This study may provide some new references and a theoretical basis for further research on ice adhesion behavior in different laboratories. [Display omitted] • An optimized methodology was adopted to measure ice-asphalt adhesion strength. • Investigating the effect of experimental parameters on ice-asphalt adhesion strength. • Theoretical model was established to predict ice-asphalt adhesion strength. [ABSTRACT FROM AUTHOR]

This study proposes and applies a systematic data analysis methodology to analyse experimental data for high-performance concrete (HPC) samples with different admixtures for offshore fan foundation grouting materials uses. In contrast with other relevant research, including experimental studies, the materials physics and chemistry studies, or cementitious material portfolio determination studies, this data-driven analysis provides a deep exploration of the experimental variables associated with the test data. To offer complete and in-depth perspectives, several methods are employed for the data analyses, including correlation analysis, cosine similarity analysis, simple linear regression (SLR) modelling, and heat map and heat-based tabularised visualisations; the outcome is a proposed methodology that is easily implementable. The results from these methods are validated using a pairwise comparison approach (PCA) to avoid unnecessary interference between data variables. There are several potential contributions from this work, including insights for cohered groups of variables, techniques for double check and ‘third check’, an established ‘knowledge base’ consisting of 504 SLR predictive models with their effectiveness (significance) and prediction accuracy (data-model fitness) used in practical applications, an alternative visualisations of the results, three data transforms which can be omitted in a future analysis, and three valuable theory-linking perspectives (e.g., for the relationships between destructive and non-destructive tests with respect to the variable categories). The implication that some variables are interchangeable will make future experiments less labour intensive and time consuming for pre-project HPC material testing.

• This article uses solid waste materials to replace Portland cement in material selection, which is green and low-carbon. • In this study, no additional strong alkali activator was added during the foaming process, but rather the alkalinity of the alkaline solid waste itself was used for excitation. Flammable conventional organic foam materials imply fire hazards to constructions and buildings. Given that the accumulated alkaline solid wastes, such as red mud (RM) and carbide slag (CS), seriously damage the ecology, their safe utilization in developing nonflammable inorganic foam building materials is very lucrative. This study produced whole solid waste inorganic foam materials through chemical foaming, with aluminum powder used as a foaming agent. This preparation process was optimized by studying the effects of aluminum powder content, water-binder ratio, and stirring water temperature(Water temperature used in the experiment) on the absolute dry density, compressive strength, porosity, pore morphology, and pore size distribution of the specimens. The increase in aluminum powder content and water-binder ratio lead to a decrease in density and compressive strength, while the rising stirring water temperature resulted in opposite trends in porosity and compressive strength. The optimal experimental parameters (aluminum powder content of 1 %, water-binder ratio of 0.7 wt%, and stirring water temperature of 40℃) provide the foam specimen's porosity of 33.2 %, compressive strength of 0.41 MPa after 28 days, and a dry density below 0.5 g/cm3. [ABSTRACT FROM AUTHOR]

Large muscle defect negatively influences people's life, the common treatment is muscle transplantation but limited by donor source, large area wound, etc. Therefore, a muscle tissue scaffold with superimposed vascular network was developed. For ensuring the performance of fascia layer which alternated by poly(ethylene-co-vinyl alcohol) (EVOH) nanofiber mats encapsulated with Ag, the mechanical properties and water vapor transmission of different samples (7.5%, 10%, 12.5% EVOH solution densities with 0.02, 0.05, 0.08 g/ml of Ag, respectively) were mainly discussed. Meanwhile, the main parameters (voltage, tip-to-collector distance, solution density, concentration of Ag) were compared to find their influence on fabricating nanofibers. [ABSTRACT FROM AUTHOR]

The interactions of nanomedicines with biological environments is heavily influenced by their physicochemical properties. Formulation design and optimization are therefore key steps towards successful nanomedicine development. Unfortunately, detailed assessment of nanomedicine formulations, at a macromolecular level, in rodents is severely limited by the restricted imaging possibilities within these animals. Moreover, rodent in vivo studies are time consuming and expensive, limiting the number of formulations that can be practically assessed in any one study. Consequently, screening and optimisation of nanomedicine formulations is most commonly performed in surrogate biological model systems, such as human-derived cell cultures. However, despite the time and cost advantages of classical in vitro models, these artificial systems fail to reflect and mimic the complex biological situation a nanomedicine will encounter in vivo. This has acutely hampered the selection of potentially successful nanomedicines for subsequent rodent in vivo studies. Recently, zebrafish have emerged as a promising in vivo model, within nanomedicine development pipelines, by offering opportunities to quickly screen nanomedicines under in vivo conditions and in a cost-effective manner so as to bridge the current gap between in vitro and rodent studies. In this review, we outline several advantageous features of the zebrafish model, such as biological conservation, imaging modalities, availability of genetic tools and disease models, as well as their various applications in nanomedicine development. Critical experimental parameters are discussed and the most beneficial applications of the zebrafish model, in the context of nanomedicine development, are highlighted. Unlabelled Image [ABSTRACT FROM AUTHOR]

Copyright of Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara Ion Ionescu de la Brad Iasi, Seria Horticultura is the property of University of Agricultural Sciences and Veterinary Medicine (Editura Ion Ionescu de la Brad) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recycling and reuse of automotive plastics have elicited global attention due to the increasing number of end-of-life vehicles. Through the single-factor experiment, a high-voltage triboelectrostatic sorting device was developed to separate polypropylene (PP), polyurethane (PU), and polyvinylchloride (PVC) in a plastic mixture commonly used in exterior and interior parts of passenger vehicles. Products of PP, PU, and PVC were obtained after two-stage separation; their purity exceeded 95%, and their productivities were 74%, 94%, and 41%, respectively. The appropriate experimental parameters for high voltage level and rotational speed of the friction drum and cylinder electrode for the first stage of separation were 35 kV, 30 rpm, and 35 rpm, respectively, and the parameters for the second stage of separation were 35 kV, 30 rpm, and 25 rpm, respectively. Results showed that hybrid materials should be selected based on the triboelectric series to separate three-component plastic mixtures feasibly. [ABSTRACT FROM AUTHOR]

Co-synthesis of hydrogen and nanocarbon via methane cracking is a single step technique which meets ever growing need of greenhouse gas (GHG) free energy. Additionally, as produced multifunctional nano-carbon that have a variety of technological applications reduces the process cost. This review is intended to provide a critical and wide-ranging assessment of impact of metal catalyst characteristics and methane decomposing parameters on hydrogen and nanocarbon yield, as well as the alteration of characteristic properties of as-produced nanocarbon. The major factors influencing thermocatalytic decomposition of methane (TCD) includes catalyst support, porosity, surface area, particle size, metal loading, calcination temperature, feed flow rate, partial pressure, and reaction temperature. Literature survey emphasizes that higher temperature and partial pressure together with lower feed flow is the reliable experimental condition to yield high purity hydrogen. Furthermore, initial catalytic activity resembles to the chemical structure of the catalyst and long term activity corresponds to the physical characteristics of catalyst. The structural features of as-produced nanocarbon have inevitable association with catalytic characteristics, such as textural supporters, particle size and material dispersion by physical interactions or chemical interaction. The interaction of metal and support results in modification of electronic properties of metal particles and subsequently influence their catalytic characteristics. In addition to investigation of one-factor-at-a-time experiments, the latest studies with Design of Experiment are also thoroughly reviewed, which analyze the influence of each process variables and their interactions simultaneously. The manuscript, then, extended to the microscopic level understandings on TCD for synthesis of nanocarbon and hydrogen via computational study in the finishing section. [ABSTRACT FROM AUTHOR]

The use of atom probe tomography (APT) for mineral analysis is contributing to fundamental studies in Earth Sciences. Meanwhile, the need for standardization of this technique is becoming evident. Pending the use of mineral standards, the optimization of analysis parameters is needed to facilitate the study of different mineral groups in terms of data collection and quality. The laser pulse rate and energy are variables that highly affect the atom evaporation process occurring during APT analysis, and their testing is important to forecast mineral behavior and obtain the best possible data. In this study, five minerals representative of major groups (albite, As-pyrite, barite, olivine, and monazite) were analyzed over a range of laser pulse energies (10-50 pJ) and rates (100-250 kHz) to assess output parameter quality and evaluate compositional estimate stoichiometry. Among the studied minerals, As-pyrite, with the higher thermal conductivity and lower band gap, was the most affected by the laser pulse variation. Chemical composition estimates equal or close to the general chemical formula were achieved for monazite and As-pyrite. The analysis of multihit events has proved to be the best strategy to verify the efficacy of the evaporation process and to evaluate the best laser pulse setting for minerals., Competing Interests: Conflict of Interest The authors declare that they have no competing interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Microscopy Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

A description is given of the traveling solvent technique, which has been used for the crystal growth of both congruently and incongruently melting materials of many classes of intermetallic, chalcogenide, semiconductor and oxide materials. The use of a solvent, growth at lower temperatures and the zoning process, that are inherent ingredients of the method, can help to grow large, high structural quality, high purity crystals. In order to optimize this process, careful control of the various growth variables is imperative; however, this can be difficult to achieve due to the large number of independent experimental parameters that can be grouped under the broad headings ‘growth conditions’, ‘characteristics of the material being grown’, and ‘experimental configuration, setup and design’. This review attempts to describe the principles behind the traveling solvent technique and the various experimental variables. Guidelines are detailed to provide the information necessary to allow closer control of the crystal growth process through a systematic approach. Comparison is made between the traveling solvent technique and other crystal growth methods, in particular the more conventional stationary flux method. The use of optical heating is described in detail and successful traveling solvent growth by optical heating is reported for the first time for crystals of Tl 5 Te 3 , Cd 3 As 2 , and FeSc 2 S 4 (using Te, Cd and FeS fluxes, respectively). [ABSTRACT FROM AUTHOR]

In this paper, two types of melanoma and glioblastoma cancer cell lines are treated with cold atmospheric plasma to assess the effect of several parameters on the cell viability. The cell viability decreases with treatment duration and time until analysis in all cell lines with varying sensitivity. The majority of dead cells stains both AnnexinV (AnnV) and propidium iodide, indicating that the plasma-treated non-viable cells are mostly late apoptotic or necrotic. Genetic mutations might be involved in the response to plasma. Comparing the effects of two gas mixtures, as well as indirect plasma-activated medium versus direct treatment, gives different results per cell line. In conclusion, this study confirms the potential of plasma for cancer therapy and emphasizes the influence of experimental parameters on therapeutic outcome. [ABSTRACT FROM AUTHOR]

Characterizing the micropore and mesopore structure of organic shale is critical for understanding the storage state and flow mechanism of shale gas. In comparison with microscopic observation and radiation detection methods, up to now, N 2 physisorption has been widely used for quantitatively analyzing the mesopores in organic shale. Use of this method is rare for micropores. It is well known that the effectiveness of N 2 physisorption in pore structure analysis is mostly influenced by both its experimental procedure and the interpretation models. This paper explores the effect of experimental preparation process, including sample size, outgassing temperature, vacuum pump, and equilibrium time threshold, on N 2 physisorption. Within, a standard experimental procedure for organic shale sample preparation was recommended. Moreover, a comprehensive validation was performed on the most available interpretation models for characterizing and comparing micropore and mesopore structures. According to the CO 2 adsorption results, the Horvath–Kawazoe (HK) model worked best for organic shale micropore analysis, especially when carbon and aluminosilicate oxide ion were used as the adsorbents to represent organic matter and inorganic minerals, respectively. The Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) models worked well for characterizing mesopores in organic shale, but methods based on density functional theory lost their effectiveness for organic shale due to the lack of a suitable kernel. [ABSTRACT FROM AUTHOR]

Properties of methyl orange (MO) degradation and their dependence on experimental parameters such as electrical polarity, pulse frequency, the material, and thickness of the discharge electrode, as well as electrode gap distance were investigated in a laboratory scale pulsed corona discharge system. The MO degradation and H2O2 generation were significantly enhanced by positive polarity than negative polarity because of the numerous micro-discharges that were generated by the space charge effect induced by positive polarity. The increase of pulse frequency reduced the MO degradation even though it enhanced the number of streamers produced. An electrode material having low electrical and thermal conductivities resulted in more MO degradation. The smaller the curvature radius of the discharge electrode, the more efficient the MO degradation was. The number of electrode needles and the electrode gap distance also affected MO degradation during the discharge process. [ABSTRACT FROM AUTHOR]

Electrospinning is a highly versatile technique to prepare continuous fibers with diameters of the order of nanometers. The remarkable high aspect ratio and high porosity bring electrospun nanofibers highly attractive to various nanotechnological applications such as filtration membranes, protective clothing, drug delivery, tissue-engineering, biosensors, catalysis, fuel cells and so on. In this review, we collectively summarized the recent progress in developments of the electrospun ultrafine polyamide-6 based nanofibers preparation, characterization and their applications. Information of this polyamide-6 and composites together with their processing conditions for electrospinning of ultrafine nanofibers has been summarized in this review. The recent developments made during last few years on these materials are addressed in this review. We are anticipating that this review certainly drive the researchers for developing more intensive investigation for exploring in many technological areas. [ABSTRACT FROM AUTHOR]

Abstract: Acoustic cavitation plays an important role in sonochemical processes and the rate of sonochemical reaction is influenced by sonication parameters. There are several methods to evaluate cavitation activity such as chemical dosimetry. In this study, to comparison between iodide dosimetry and terephthalic acid dosimetry, efficacy of sonication parameters in reactive radical production has been considered by iodide and terephthalic acid dosimetries. For this purpose, efficacy of different exposure parameters on cavitations production by 1MHz ultrasound has been studied. The absorbance of KI dosimeter was measured by spectrophotometer and the fluorescence of terephthalic acid dosimeter was measured using spectrofluorometer after sonication. The result of experiments related to sonication time and intensity showed that with increasing time of sonication or intensity, the absorbance is increased. It has been shown that the absorbance for continuous mode is remarkably higher than for pulsing mode (p-value<0.05). Also results show that with increasing the duty cycles of pulsed field, the inertial cavitation activity is increased. With compensation of sonication time or intensity in different duty cycles, no significant absorbance difference were observed unless 20% duty cycle. A significant correlation between the absorbance and fluorescence intensities (count) at different intensity (R =0.971), different sonication time (R =0.999) and different duty cycle (R =0.967) were observed (p-value<0.05). It is concluded that the sonication parameters having important influences on reactive radical production. These results suggest that there is a correlation between iodide dosimetry and terephthalic acid dosimetry to examine the acoustic cavitation activity in ultrasound field. [Copyright &y& Elsevier]

Nano-sized AgNbTaO (x = 0.4) ceramic powders were synthesized by a modified citrate sol-gel route. Homogeneous Ag-Nb-Ta precursor gel was prepared with silver citrate, niobium citrate, and tantalum citrate as source of Ag, Nb and Ta, respectively. Citrate acid and ethylene glycol were used as the complexing agents. The structural variation of the AgNbTaO powder with annealing temperature was studied by TG-DTA and X-ray diffraction. The precursor gel calcinated at 680 °C produced a pure perovskite phase. The effects of experimental parameters including pH value of the solution and the proportion of citric acid to the metal ions on the formation of homogeneous and microstructure of the powders were also investigated. The results indicated that a homogeneous Ag-Nb-Ta precursor gel with no precipitate was formed at about pH = 6 and the optimum molar ratio of citric acid and the metal ions were 2:1-3:1. The XRD data was analysis and the correlation between dielectric properties and (Nb,Ta)O octahedra was discussed. [ABSTRACT FROM AUTHOR]

A data-analysis methodology is presented for the characterization of three-dimensional microstructures of polycrystalline materials from data acquired using three-dimensional X-ray diffraction (3DXRD). The method is developed for 3DXRD microscopy using a far-field detector and yields information about the centre-of-mass position, crystallographic orientation, volume and strain state for thousands of grains. This first part deals with pre-processing of the diffraction data for input into the algorithms presented in the second part [Sharma, Huizenga & Offerman (2012). J. Appl. Cryst. 45, 705-718] for determination of the grain characteristics. An algorithm is presented for accurate identification of overlapping diffraction peaks from X-ray diffraction images, which has been an issue limiting the accuracy of experiments of this type. The algorithm works in two stages, namely the identification of overlapping peaks using a seeded watershed algorithm, and then the fitting of the peaks with a pseudo-Voigt shape function to yield an accurate centre-of-mass position and integrated intensity for the peaks. Regions consisting of up to six overlapping peaks can be successfully fitted. Two simulations and an experiment are used to verify the results of the algorithms. An example of the processing of diffraction images acquired in a 3DXRD experiment with a sample consisting of more than 1600 grains is shown. Furthermore, a procedure for the determination of the parameters of the experimental setup (global parameters) without the need for a calibration sample is presented and validated using simulations. This is immensely beneficial for simplifying experiments and the subsequent data analysis. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we investigated the influence of experimental parameters on the assembly of single-walled carbon nanotubes (SWNTs) by dielectrophoresis (DEP) process. Designed experimental parameters were adopted to assemble SWNTs by DEP. I-V characteristics were measured and the assembled number of electrodes was enumerated by scanning electron microscopy (SEM). The results show that there was an ohmic contact formed between the assembled metallic SWNTs and the electrode. The variation of experimental parameters such as the SWNT solution concentration, deposition time, voltage magnitude and frequency can have significant impacts on the assembly productivity. Optimum for high assembly productivity of single-bundle of SWNTs was discussed and proposed at last. [Copyright &y& Elsevier]

Abstract: A mechanically stabilized earth (MSE) wall behaves as a flexible coherent block able to sustain significant loading and deformation due to the interaction between the backfill material and the reinforcement elements. The internal behaviour of a reinforced soil mass depends on a number of factors, including the soil, the reinforcement and the soil/structure interaction and represents a complex interaction sol/structure problem. The use of parameters determined from experimental studies should allow more accurate modelling of the behaviour of the MSE structures. In this article, a reference MSE wall is modelled from two points of view: serviceability limit state “SLS” and ultimate limit state “ULS”. The construction of the wall is simulated in several stages and the soil/interface parameters are back analysed from pullout tests. An extensive parametric study is set up and permits to highlight the influence of the soil, the reinforcement and the soil/structure parameters. The behaviour of MSE walls with several geosynthetic straps is compared with the metallic one. Several constitutive models with an increasing complexity have been used and compared. The results obtained from stress-deformation analyses are presented and compared. The use of geosynthetic straps induces more deformation of the wall but a higher safety factor. To design theses walls the important parameters are: the soil friction, the cohesion, the interface shear stiffness and the strip elastic modulus. It is shown that for wall construction that involves static loading conditions, the modified Duncan–Chang model is a good compromise but induces slightly lower strip tensile forces due to the fact that it do not take into account of dilatancy before failure. [Copyright &y& Elsevier]

Abstract: Central events of the ultrasonic action are the cavitation bubbles that can be considered as microreactors. Adiabatic collapse of cavitation bubbles leads to the formation of reactive species such as hydroxyl radicals (ogen peroxide (H2O2) and hydroperoxyl radicals (HOOl chemical methods were used to detect the production of these reactive moieties in sonochemistry. In this work, the influence of several operational parameters on the sonochemistry dosimetries namely KI oxidation, Fricke reaction and H2O2 production using 300kHz ultrasound was investigated. The main experimental parameters showing significant effect in KI oxidation dosimetry were initial KI concentration, acoustic power and pH. The solution temperature showed restricted influence on KI oxidation. The acoustic power and liquid temperature highly affected Fricke reaction dosimetry. Operational conditions having important influence on H2O2 formation were acoustic power, solution temperature and pH. For the three tested dosimetries, the sonochemical efficiency was independent of liquid volume. [Copyright &y& Elsevier]

Abstract: This paper presents the results of investigations related to the development of a mediated electrochemical oxidation (MEO) process-based wet scrubbing method for NO and NO2 abatement from a simulated NO-air flue gas mixture. The Ag(II) redox mediator in nitric acid medium generated in an electrochemical cell was circulated continuously through a packed-bed column by a closed loop, and the NO x gas was oxidatively removed by absorption/oxidation. The outlet gas from scrubber-I was subsequently admitted into scrubber-II for further continuous washings by 3molL−1 HNO3. Numerous experimental runs were carried out in order to observe the performance of the wet scrubber-electrochemical cell integrated system as a function of the operating conditions: the initial NO concentration in the feed (100–400mgL−1), gas flow rate (0.061–0.243ms−1), liquid flow rate (0.012–0.049ms−1), concentration of silver ion mediator (0.01–0.1molL−1), nitric acid concentration (3–6molL−1), and the temperature (15–45°C). Low initial NO feed, low gas flow rates, high liquid flow rates, high HNO3 acid concentration, Ag(I) concentration as low as 0.05molL−1 and low temperatures were most suitable for high removal performance. Total removal (100%) of NO and 80% removal of NO x were achieved in the oxidation with electrogenerated Ag(II) in a single stage gas scrubbing in scrubber-I. But, interestingly, a second stage gas scrubbing by a simple HNO3 (3molL−1) wash in scrubber-II led to a better removal of NO x with overall efficiency reaching 90% as well. This is an alternative green treatment process for zero emission of waste gases. Some NO x removal studies were also performed using Ce(IV)/Ce(III) redox mediator system, and the effect of nitric acid concentration and temperature examined, for a comparison with Ag(II)/Ag(I). [Copyright &y& Elsevier]

This study reports the effect of heat input (21.3–41.3 J/mm) on the microstructure and mechanical properties of pulsed Nd: YAG laser butt welded UNS N10276 (Hastelloy C-276) and UNS N4400 (Monel 400) sheets. The different heat input was achieved by changing the experimental parameters viz., welding speed (350, 400, 450 mm/min), pulse energy (8, 10, 12 J) and pulse width (5, 6, 7 ms). Though the weld macrostructure exhibit full penetration, the morphology and top weld width differs for the attempted conditions. Weld zone microstructures at lower, medium and higher heat input conditions display unmixed islands, dendrite grains with a slender heat affected zones (HAZ) and Cr-carbide rich reaction compounds respectively. Highest micro-hardness is witnessed for a heat input of 30 J/mm. The tensile strength of the weld joints reaches a maximum and tends to decrease with the increasing heat input. [ABSTRACT FROM AUTHOR]

Abstract: In this communication, the experimental parameters and sorption isotherms of CO2 on moisture-equilibrated Argonne premium coal samples provided by Goodman et al. [Goodman, A.L., Busch, A., Bustin, R.M., Chikatamarla, L., Day, S., Duffy, G.J., Fitzgerald, J.E., Gasem, K.A.M., Gensterblum, Y., Hartman, C., Jing, C., Kross, B.M., Mohammed, S., Pratt, T., Robinson Jr., R.L., Romanov, V., Sakurovs, R., Schroeder, K., White, C.M., 2007. Inter-laboratory comparison II: CO2 isotherms measured on moisture-equilibrated Argonne premium coals at 55°C and up to 15 MPa. International Journal of Coal Geology 72, 153–164] were used to investigate the reasons that CO2 sorption on coal diverged significantly among the laboratories at high pressure. We demonstrate that the experimental parameters for manometric equipment affect the CO2 isotherms at high pressure. High adsorption values may be obtained with a higher volume in the reference cell or a lower void volume in the sample cell. Although the impact of experimental parameters for manometric equipment on CO2 sorption on coals is not clear, the investigation of the equation of the Gibbs excess adsorption used to obtain incremental adsorption shows that higher sorption of CO2 can be obtained with a higher ratio of the volume of the reference cell to the void volume of the sample cell for manometric equipment. On the other hand, higher adsorption is difficult to obtain at high pressure with a smaller volume ratio. [Copyright &y& Elsevier]

The present research is a study of experimental parameters that affect the resolution of a test mixture of estrogens by packed column supercritical fluid chromatography. The parameters that were evaluated included fluid flow rate, effect on resolution and retention times of the type and concentration of four organic modifiers, namely methanol, ethanol, isopropanol, and acetonitrile. Also, the effect of column type on the resolution of a mixture of estrogen metabolites was studied. Two packing materials cyanopropyl silica and Betasil diol silica were selected for this study. The following percentages of each of the packing materials were used in columns connected in series for the separation of the test mixture:100.0% CPS, 37.5% CPS/62.5% Diol, 50% CPS/50% Diol, 62.5 CPS/32.5% Diol, and 100.0% Diol. The results indicated that connecting two columns having the same dimensions (a ratio of one-to-one CPS/Diol) in series gave the best resolution. There was no effect on retention times or resolution when the two columns were reversed, i.e., column order has no effect. Also, retention times were a function of the organic modifier; methanol gave the shortest retention times, with approximately the same separation factor as the other three modifiers. [ABSTRACT FROM AUTHOR]

Abstract: In this letter we specify the scaling laws of the physical parameters necessary to operate a SASE FEL in the quantum regime with a laser wiggler. We also show that this is more feasible in the quantum regime than in the classical one. Specific examples are given. [Copyright &y& Elsevier]

A 3D simulation tool for solid oxide fuel cells is presented. The aim of this work is to predict current density, flow, temperature and concentration fields in order to compare and optimize repeat element geometry for a whole stack. A commercial CFD tool was used, solving mass, momentum and energy equations; whereas chemical kinetic equations are computed from external sub-routines. A steady-state case is presented, fed with hydrogen. The flow is laminar for both air and fuel. Radiative heat transfer is taken into account between inner surfaces. On boundaries, convective and radiative heat transfers are assumed at external surfaces between repeat element and oven. Due to the large range of dimensions (cells: 300 μm thick, gas channels: 1 mm height, whole cell: 80 mm×80 mm) a fine mesh was needed. Data for conductivities and kinetics were estimated from experiments performed in-house. Simulation results are presented and compared to real repeat element test measurements for the current-potential characteristics. [Copyright &y& Elsevier]