Search

The determination of water hardness is performed by EDTA complexometric titration, in the presence of Eriochrome Black T (EBT) as a visual end point indicator. EBT is an azo dye that can be an environmental problem. Therefore, the present work investigated the possibility of using the solar photo-Fenton system as a treatment to remove EBT from the wastewater of hardness determination process. The solar photo-Fenton reagents were potassium ferrioxalate, at 1 mmol L−1, as the catalyst and the source of iron, and hydrogen peroxide, at 10 mmol L−1. The efficiency of the treatment was monitored by COD, BOD, TOC, HPLC, and ecotoxicological analyses. Organic matter removal values higher than 60% were obtained in all the experiments carried out under 30 min of solar irradiation (7.313 J cm−2). The ecotoxicity of the treated effluents decreased by an average of 75%, which was in accordance with Brazilian regulations. The results indicated that the solar photo-Fenton process could be an attractive option for treating the effluent from water hardness determination, using solar radiation, presenting low risk to the environment and using low concentrations of reagents, including those required to decrease the system pH for process application and increase it to neutral pH before wastewater disposal. [ABSTRACT FROM AUTHOR]

Quercus suber woodlands are widely distributed around the Western Mediterranean basin. Although assumed well-adapted to recurrent seasonal droughts, water availability during critical phases can limit Q. suber crown development and, consequently, photoassimilate production and growth. This work aims to assess the relationships between climate conditions and seasonal and interannual variation of multiple vegetative and reproductive growth traits in Q. suber and identify possible mechanisms governing within-tree competition for resources and trade-offs between vegetative and reproductive growth. Data collection occurred between 2010 and 2019 and involved the monthly monitoring of reproductive and vegetative phenology, stem radial growth, and litterfall collection in a Q. suber woodland in central Portugal. Winter and autumn precipitation reductions (20 and 30%, respectively) during 2015–2019 resulted in a 23% decrease in leaf biomass production (compared to 2010–2014). Results show that mean March temperatures have a pivotal role in balancing vegetative/reproductive biomass investment, being positively correlated with the growth of vegetative structures (r = 0.81) and negatively correlated with acorn production (r=-0.83). PCA results also confirm the existence of competitive interaction between reproductive and vegetative growth in Q. suber trees, with mast cropping years resulting in reductions in annual leaf biomass production (26%). Dry years affected annual stem radial growth negatively (ca. 48%), reducing the period of phellogen activity and anticipating annual radial growth peaks by two months, consequently shortening the window for a safe cork extraction. Our results provide valuable information to adapt the management of Q. suber woodlands to ongoing environmental changes and contribute to ecosystem sustainability. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the functions of the stomatognathic system in children with or without molar-incisor hypomineralization (MIH). Methods: For this cross-sectional study, 72 children aged 6–12 years were recruited and divided in two groups: with MIH (G1) and without MIH (G2). T-SCAN was used to verify the distribution of occlusal contacts, gnathodynamometer to measure maximum molar bite force, and Iowa Oral Pressure Instrument (IOPI) to assess the strength of facial expression muscles. The t test and paired t test (p ≤ 0.05) were used for statistical comparisons. Results: The molars affected by MIH exhibited lower distribution of occlusal forces (p < 0.001) and lower maximum molar bite force (p < 0.05) compared to the molars in the control group. However, there was no difference between the MIH-affected sides compared to the unaffected side, nor between the molars affected by MIH and their antagonists (p > 0.05). There were no differences in the forces of the facial expression muscles between the groups. Conclusions: These findings suggest that MIH significantly impacts occlusal force distribution and bite force, but not facial expression musculature. [ABSTRACT FROM AUTHOR]

The CMS detector, including its muon system, has been operating at the CERN LHC in increasingly challenging conditions for about 15 years. The muon detector was designed to provide excellent triggering and track reconstruction for muons produced in proton–proton collisons at an instantaneous luminosity (L ) of 1 × 10 34 cm - 2 s - 1 . During the Run 2 data-taking period (2015–2018), the LHC achieved an instantaneous luminosity of twice its design value, resulting in larger background rates and making the efficient detection of muons more difficult. While some backgrounds result from natural radioactivity, cosmic rays, and interactions of the circulating protons with residual gas in the beam pipe, the dominant source of background hits in the muon system arises from proton–proton interactions themselves. Charged hadrons leaving the calorimeters produce energy deposits in the muon chambers. In addition, high-energy particles interacting in the hadron calorimeter and forward shielding elements generate thermal neutrons, which leak out of the calorimeter and shielding structures, filling the CMS cavern. We describe the method used to measure the background rates in the various muon subsystems. These rates, in conjunction with simulations, can be used to estimate the expected backgrounds in the High-Luminosity LHC. This machine will run for at least 10 years starting in 2029 reaching an instantaneous luminosity of L = 5 × 10 34 cm -2 s -1 and increasing ultimately to L = 7.5 × 10 34 cm -2 s -1 . These background estimates have been a key ingredient for the planning and design of the muon detector upgrade. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the effect of copper powder oxidation on the deposition efficiency, microstructure, wear and corrosion resistance. The gas-atomized copper powders in the as-received (Cu-Safina and Cu-FST) and oxidized states (Cu-treat, oxidized in air, 25 °C for 5 months; Cu-treat1, oxidized at 100 °C for 1 h; and Cu-treat2, oxidized at 200 °C for 1 h) were used to prepare the coatings by cold gas spray (CGS). XPS analysis detected Cu2O and CuO for all feedstock powders, increasing for oxidized ones. The deposition efficiency and thickness of the coatings followed the order: Cu-Safina > Cu-FST > Cu-treat1 > Cu-treat > Cu-treat2. For oxidized coatings, SEM images showed more defected microstructure, increase in pores, and microcracks. Cu-FST coating showed a sliding wear rate of (0.13 ± 0.01) × 10-4 mm3 N−1 m−1), and abrasive wear rate of (3.2 ± 0.2) × 10−4 mm3 N−1 m−1. Gas-atomized powder coatings showed a better corrosion resistance performance. The electrolyte did not reach the substrate/coating interface for t ≥ 700 h and the coatings resisted for 2000 h in salt fog tests. However, oxidized coatings showed low corrosion resistance due to the presence of cracks and defects, and the coating/substrate was severely damaged after ≈100 h in 3.5wt.%NaCl solution. [ABSTRACT FROM AUTHOR]

Data collection by citizen scientists is emerging as an important practice for biodiversity detection, mapping, and compilation of big data in open online platforms such as iNaturalist, acting as a source of biodiversity discovery. However, the validation of species identification is a central issue for the scientific use of these data. Here we compared the list of marine species in the Western Atlantic Ocean obtained in iNaturalist with that generated from scientific collections to understand whether there are taxonomic bias favoring some types of organisms, and to understand the amount of trustful information at the species level in iNaturalist. We also present the first bioblitz results of marine biodiversity in Brazil, an iNaturalist Citizen Science campaign advertised by social media, as a case study. We found that marine taxa with higher richness were well represented in iNaturalist (Arthropoda, Mollusca and Chordata), nonetheless Annelida, Bryozoa, Nematoda, Nemertea, Platyhelminthes, Porifera, Chlorophyta, and Rhodophyta were under-represented. Taxa with small, cryptic, parasitic and/or sessile organisms were poorly represented. According to the methods applied in this study, we showed that 72% of the records are probably well identified, except for Bryozoa and Platyhelminthes. Brazilian marine records in iNaturalist add up to only 1/30 of the total West Atlantic records analyzed but there was a steep increase from 2021 to 2022, as a possible contribution of our bioblitz campaign especially for Arthropoda, Echinodermata, and Annelida. We conclude that the record of marine biodiversity by citizen scientists is a valuable tool, but the engagement of taxonomists is strongly recommended to increase the correct identification of species. [ABSTRACT FROM AUTHOR]

This research aims to identify critical contamination points by nutrients, their possible origin (point and nonpoint sources), their spatial distribution, and possible attenuation by natural and anthropogenic processes. The study area is the Velhas River Basin, located in the Southeast Region of Brazil (17.0°–20.5° S; 43.5°–45.0°W). A historical series of water quality monitoring, land cover map, demographic and agricultural censuses, sewage treatment diagnostics, and local hydrographic networks were used to achieve the objectives. In addition, the regions were divided into incremental areas, enabling individualized analyses of each sub-basin. Descriptive statistics, seasonality, categorized data tests, agglomerative hierarchical cluster analysis, and principal component analysis were used. There was a significant contribution of nutrients in the most important urban agglomeration of the basin, resulting in peak concentrations measured at that place. Although the values were reduced by the mouth (650 km), the percentage of legislation violations remained high. The effects of punctual contamination were intensified by the low percentage of treated sewage in the basin, the absence of adequate treatment technologies to remove nutrients, and the disorderly urbanization. Furthermore, it was estimated that the nutrient load from animal husbandry is approximately 75% of the load from domestic effluents due to the high number of cattle in the basin and the low percentage of forests. [ABSTRACT FROM AUTHOR]

Coordination compounds are formed by the reaction between ligands in the presence of one or more metal centers. In the present work, a copper(II) complex (CuL) was synthesized and evaluated as a catalyst in a Fenton-like reaction for the degradation of organic pollutants, using the reactive dye Drimaren Red X-6BN (DRX-6BN) as a model substrate, in the absence of light. Kinetic studies with DRX-6BN and soluble chemical oxygen demand removal were developed under the condition of a face-centered cube central composite design (CCD) (CCDoptimum) and its variations. The model obtained by CCD proved to be reliable for predicting the results in the studied ranges. The highest reaction rate (kapp = 4.05 × 10–2 min−1) and DRX-6BN removal (90.17 ± 0.52%) were reached at pH 8.82 ± 0.05 and initial hydrogen peroxide (H2O2) and CuL concentrations of 1.17 × 10–2 and 2.67 × 10–4 mol L−1, respectively. Concerning the mechanism, degradation involves dye adsorption onto CuL and oxidation by hydroxyl radicals (·OH) mainly. Mineralization after 60 min was around 50 and 60% under various conditions. The catalyst was significantly stable after storage and could be reused for three cycles, losing about 20% of the total activity. These results suggest that CuL is a promising catalyst for Fenton-like reactions for the degradation of pollutants. [ABSTRACT FROM AUTHOR]

Insight into the plasma properties of high-speed ionized flows is key for the validation of predictive aerothermodynamic tools for atmospheric entry applications, namely plasma radiation which will be highly dependent on the flow electron densities, which accordingly need to be accurately estimated. We performed an extensive review on past re-entry microwave diagnostics, including both in-flight and ground-test experiments. This work assesses the peculiar characteristics of entry plasmas, and derives functional requirements for microwave diagnostics tailored for such applications. A preliminary analysis, including a simulation of electromagnetic environment for the RAM-C II flight experiment, obtained through a CFD code coupled to an electromagnetic propagation code, is presented. The obtained results outline the adequacy of such diagnostics for improving verification and validation for high-speed entry plasma flows. [ABSTRACT FROM AUTHOR]

This work studies the dielectric properties in the microwave region (MW) of the Ba2TiSi2O8 (BTS) ceramic with TiO2 additions and its applications as a dielectric resonator antenna (DRA). In this study, structural characterization through x-ray diffraction (XRD) is performed and the Rietveld refinement is used to confirm the phases formed. Analysis of the morphology of the materials is performed using scanning electron microscopy (SEM). The resonant frequency temperature coefficient (τf) reveals a variation from − 47.0 ppm°C−1 to + 16.5 ppm°C−1. The dielectric properties in the MW region reveal an increase in the dielectric permittivity (εr) and a decrease in the loss tangent (tanδ) of the samples. Numerical simulation shows good fits of the experimental data, with gain and directivity standing out, ranging from 4 dBi to 6 dBi and radiation efficiency below 80%. The results demonstrate that the samples can operate in C-band electronics, Wi-Fi devices, meteorological radar systems, etc. [ABSTRACT FROM AUTHOR]

Cellulose-based materials have been extensively investigated due to their abundance, renewable nature, and low abrasiveness and density. Cellulose nanocrystals (CNCs) stand out as nanometric particles of increasing technological interest, and also due to their potential use as nano-reinforcements to polymer composites. Since the effect of ultrasonic treatment on the structure and properties of CNCs is not yet fully understood, in this study the effect of ultrasonic output and hydrolysis time on yield and morphological, structural, and thermal properties of nanocrystals from microcrystalline cellulose (MCC) was studied. CNCs were prepared by conventional hydrolysis and compared to sonochemical extraction using 64 vol% H2SO4 at 45 °C. Sonication power varied from 50, 70 and 90%, and for each value a kinetic study was performed as a function of hydrolysis time until a colloidal gel suspension was obtained. Results showed that it was possible to obtain CNCs from MCC with reduced extraction time, whose thermal stability, aspect ratio and crystallinity index are comparable to those obtained by conventional acid hydrolysis. The ultrasound power intensity was the most important parameter to increase CNC sonochemical extraction productivity. The optimal CNC yield occurred at predetermined hydrolysis time intervals for each set of variables of low-intensity ultrasound-assisted hydrolysis. The disaggregation of freshly produced CNCs from MCC particles occurred simultaneously to size reduction of previously produced CNCs and conversion of amorphous phase into sugars. Due to the non-selective nature of sonochemical hydrolysis, it was proposed that hydrolysis proceeds regardless of the size and crystallinity degree of cellulose particles dispersed in the acidic medium. Therefore, there was an optimal hydrolysis time as a function of CNC yield for each set of hydrolysis parameters, since prolonged extraction times leaded to deterioration of the morphological and structural properties of CNCs. [ABSTRACT FROM AUTHOR]

We obtain new exact solutions for the gravitational field equations in the context of f(R, T) gravity, thereby obtaining different classes of black holes surrounded by fluids, taking into account some specific values of the parameter of the equations of state, w. In order to obtain these solutions in the context of f(R, T) gravity, we consider viable particular choices of the f(R, T). Considering an anisotropic energy-momentum tensor, we write the field equations with the required symmetries for this type of solution. Then, we analyze the conditions of energy in a general way and also for particular values of the parameter w of the equation of state. In addition, thermodynamic quantities, such as Hawking temperature and mass associated to the horizons of solutions, are taken into account in our analysis. [ABSTRACT FROM AUTHOR]

Aim: The objective of this study was to investigate whether dental hypersensitivity and dental fear were linked to the presence and severity of MIH. Methods: For this cross-sectional study, 1830 students between the ages of 6 and 12 years were recruited from four randomly selected schools. The Children's Fear Survey Schedule-Dental Subscale questionnaire was used to assess dental anxiety and fear. The children's self-reported dental hypersensitivity resulting from MIH was evaluated using the Wong-Baker Facial Scale and the Visual Analog Scale (VAS). Results: MIH was correlated with tooth hypersensitivity, particularly in severe cases. Dental fear was present in 17.4% of the children with MIH, but it was not associated with dental hypersensitivity, gender, or age. Conclusion: No association was found between dental fear and dental hypersensitivity in children with MIH. [ABSTRACT FROM AUTHOR]

The demand for sea cucumbers from the NE-Atlantic is increasing as a consequence of the depletion of stocks that historically supplied Asian markets. Some species from the NE-Atlantic are already showing overfishing signs due to either inefficient policies or their total absence, and they do not offer any margins of sustainability to sea cucumber fisheries. The current lack of knowledge of biological and ecological traits has led to ineffective protection of those species. Holothuria arguinensis is a good example of a temperate sea cucumber species suffering from the effects of unregulated and illegal harvest. This study aims to determine the temporal and spatial distribution patterns of H. arguinensis, assessing density and size-class structure in a NE-Atlantic population, in SW Portugal, as a function of environmental conditions. Sampling was done every 1.5 months at 6 stations defined according to habitat heterogeneity, following the coastline from the mouth of the Sado estuary to marine coastal areas. At each station, there were two habitats (rocky substrate and sandy areas) sampled through SCUBA diving along 30-m random transects, each with three replicates. Individuals were counted and measured (total length) and individual behavioural parameters, such as sheltering and settlement surface, were recorded. Water column parameters, sediment composition, and substrate cover were also recorded. Generalised Linear Models were fit to the data, modelling density and size distribution of the species with respect to environmental conditions. The results indicate that the distribution of H. arguinensis was mainly determined by its ability to deal with physical environmental stressors (current), rather than the chemical properties of the water column or sediment composition. The hydrodynamic features of the region exert the greatest impact on this species' distribution and help shape habitat usage by different size class groups. [ABSTRACT FROM AUTHOR]

Multi-material structures make it possible to obtain effective solutions to engineering problems by combining the benefits of different materials to meet the requirements of different working conditions. The aim of this multifunctional 420 stainless steel-copper structure is to create a hybrid solution in which copper acts as heat-transfer enhancer (through cooling channels) while maintaining the required mechanical properties of the steel matrix. This work focuses on a combined engineering process consisting of CNC machining through holes on a 420 stainless steel surface substrate and subsequent filling with copper by hot pressing. The influence of the copper filling on the physical, chemical, microstructural, mechanical, and thermal properties of this multi-material solution was analysed. The machined area (5% of the total surface area) consisted of nine holes with a diameter of approximately 1 mm. The multi-material samples showed high densification, homogeneous microstructures, and a well-defined and sharp interface between the two materials. The microhardness values measured for the 420 stainless steel and copper were 759 and 57 HV, respectively, and the thermal conductivity of the multi-material was ≅ 59% higher than the 420 stainless steel (39.74 and 16.40 W/m K, respectively). [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic has negatively disrupted the way our economy and society functions. Nonetheless, there have also been some positive externalities of the pandemic on the environment. This paper aims to evaluate the concentration of nitrogen dioxide in Brazilian metropolitan regions after the policies adopted to confront Covid-19. In terms of methodological approach, the study employs cross-sectional quantitative analyses to compare the period of 36 days, i.e., 12 March to 16 April—before (in 2019) and after (in 2020) the pandemic declaration. The data were obtained from the Sentinel 5-P low-Earth polar satellite concerning Brazilian metropolitan regions (n = 24). Thorough spatial and statistical analyses were undertaken to identify the pre- and during pandemic nitrogen dioxide concentrations. Complementarily, Spearman's correlation test was performed with variables that impact air quality. The study results a fall in nitrogen dioxide concentration levels in 21 of the 24 metropolitan regions which was observed. The Spearman's correlation coefficient between the nitrogen dioxide variation and the vehicle density was 0.485, at a significance level of 0.05. With these findings in mind, the paper advocates that while the pandemic has a significant negative consequence on the health of population globally, a series of measures that result in a new social organization directly interfere in the reduction of air pollution that contributes to the quality of the air we breathe. [ABSTRACT FROM AUTHOR]

The increasing usage of hybrid cable-overhead lines raises concerns over the protection of short cable sections against lightning surges, because of voltage build-up in the cable section. To set a simulation model of the phenomenon is time consuming, with numerous parameters impacting the overvoltage. This paper (Part I) presents formulas able to perform a fast estimation of the maximum overvoltage at a cable-overhead line transition point in the event of shielding failure. The formulas estimate the overvoltage with and without surge arrester, as well as the energy absorbed by the surge arrester. These formulas do not require an electromagnetic transients software and they can be implemented as a script, requiring solely the geometric data of the cable and overhead line, information available in the respective datasheets. The main usefulness is a tool for a fast screening of the overvoltages and a fast evaluation of the impact of different parameters such as cable length, lightning waveform and grounding impedance. [ABSTRACT FROM AUTHOR]

This paper (Part II) continues the study from Part I by presenting formulas able to do a fast estimation of the voltage at an underground cable sheath for lightning surges striking an earth wire, with and without back-flashover. Similar to Part I, these formulas do not require an electromagnetic transients (EMT) software and can be implemented as scrip for a fast screening of potential issues, requiring solely the geometric data of the cable and the overhead line. The potential impact and limitations of the simplifications are evaluated. [ABSTRACT FROM AUTHOR]

Recent years saw increasing of harmonic distortion at transmission grids caused partly by a growing system undergrounding, leading to resonances at lower frequencies. Presently, the estimation of the harmonic distortion through simulations after significant grid changes is not sufficiently accurate, and the understanding of harmonics propagation is a topic under research. This hinders grid development by system operators, as it is not possible to assess fully the impact of new lines. This paper presents and analyses four harmonic-related phenomena: (1) impact of line asymmetry in long HVAC cables; (2) harmonic peak voltage/current along a line; (3) harmonic propagation between voltage levels; (4) fillter location. The paper summarizes the root causes and consequences of each phenomenon, together with tools and recommendations that can ease the assessment of harmonic propagation. [ABSTRACT FROM AUTHOR]

Diabetes Mellitus (DM) is both, correlated and a known risk factor for colorectal cancer (CRC). Besides favoring the incidence of CRC, DM also accelerates its progression, worsening its prognosis. Previously, hyperglycemia, the DM hallmark, has been shown to lead to aberrant glycosylation of CRC cells, heightening their malignancy both in vivo and in vitro. Here we use mass spectrometry to elucidate the composition and putative structures of N-glycans expressed by MC38 cultured in normoglycemic (LG) and hyperglycemic-like conditions (HG). N-glycans, 67, were identified in MC38 cells cultured in LG and HG. The cells grown in HG showed a greater abundance of N-glycans when compared to LNG cells, without changes in the proportion of sialylated, fucosylated and mannosylated N-glycans. Among the identified N-glycans, 16 were differentially expressed, mostly mannosylated and fucosylated, with a minority of them being sialylated. Metabolomics analysis indicates that the alterations observed in the N-glycosylation may be mostly due to increase of the activated monosaccharides pool, through an increased glucose entrance into the cells. The alterations found here corroborate data from the literature regarding the progression of CRC, advocating for development or repositioning of effective treatments against CRC in diabetic patients. [ABSTRACT FROM AUTHOR]

Selection of sewage treatment systems for protecting water resources within a watershed is a complex problem. It involves environmental, technological, operational and social aspects joint analysis associated with the treatment systems, in addition to raw or treated sewage final disposal receiving watercourses support capacities assessments. The present work proposes a methodology that could help the sewage treatment systems selection process through the combined application of water quality mathematical model, metaheuristic optimization technique (genetic algorithm) and multicriteria analysis method (theory of multi-attribute utility). The study area is the hydrographic basin Benevente River, an important watercourse located in the Espírito Santo state South region, in Brazil. Minimum efficiencies for removing organic matter and nutrients were considered in the sewage treatment systems pre-selection. For the most populous districts, such as Jabaquara, Alfredo Chaves and Alto Pongal, the ordering process, supported by multicriterial analysis, led to the selection of mechanized technologies—activated sludge processes. For all other locations, stabilization pond systems were selected. The methodology described in this work can be generally applied to the planning of wastewater treatment and final disposal in watersheds and subsidize effluents discharge and dilution in watercourses environmental licensing and granting processes. [ABSTRACT FROM AUTHOR]

Background: In automotive engineering, the piston ring-cylinder liner pair is among the most studied contacts. From the three piston rings of a conventional internal combustion engine, the top compression ring has a crucial role. The main challenge is to prevent that during the engine lifecycle, the degradation of the piston ring surface might limit the engine's durability. Objective: However, a reliable evaluation of the piston rings tribological response requires a steady method. To test and study the tribological performance of the ring-liner pair, the development of a customized test rig is presented in this work. Methods: The new oscillating tribometer will test and study the performance of new and commercial piston rings and cylinder liner solutions. According to the foreseen engine operation, four conditions were appointed to perform the control tests, and a testing protocol was established. The selected stainless-steel piston rings were coated with a diamond-like carbon layer, and the cylinder liner parts had the typical plateau honed texture in the contact surface. The friction force measures were recorded. It was also investigated the influence of distinct parameters (such as temperature and contact pressure) in the friction coefficient of this pair. Results: According to the exploratory tests, the major COF was registered for the testing condition with a lower load. In contrast, the lower COF values were recorded for those conditions with superior normal loads and temperatures. Conclusions: The functionality of the developed test rig was verified to evaluate the ring's performance and the liner contact. [ABSTRACT FROM AUTHOR]

We provide a photographic guide and taxonomic diagnosis of Chironomidae larval remains obtained from surface sediments and short cores of 92 waterbodies situated on the Yucatan Peninsula and in Central America, namely Mexico, Belize, Guatemala, El Salvador and Honduras. A total of 101 morphotypes belonging to 64 genera were identified. Chironominae was the most species-rich subfamily represented by 57 morphotypes of 34 genera. The most widespread and abundant genus was Goeldichironomus followed by Chironomus and Polypedilum. Orthocladiinae were represented by 26 morphotypes and 17 genera, with the most common one being Cricotopus. Remains of this subfamily were recorded in only 1 5 of the surveyed lakes. Tanypodinae included 17 morphotypes belonging to 12 genera. Labrundinia along with Ablabesmyia and Coelotanypus were the most common genera. Subfamily Podonominae was represented by the genus Parochlus. We believe that our study includes most of the Chironomidae genera of Central America and will have broad applicability for both paleolimnologists and aquatic ecologists. [ABSTRACT FROM AUTHOR]

Cork oak woodlands are highly biodiverse silvopastoral systems, economically and socially relevant to rural communities in many Mediterranean areas. The installation of legume-rich pasture mixtures became a common practice in these woodlands aiming to obtain higher productivity, to improve soil fertility, and to increase the amount of protein for forage. The predicted impacts of climate change will affect pasture productivity either by altering the biomass total amount or its seasonal productivity. We analysed an 8-years data series of meteorological variables and herbaceous biomass productivity collected in a certified cork oak ecosystem with a moderate tree density (177 trees ha−1) to investigate how understorey herbaceous biomass is affected by inter annual and seasonal climate variability. The field collections were carried out in two contrasting understorey management systems: a natural understorey vegetation (NU) subject to shrub clearing every 5 years, without grazing; and a sown improved pasture, installed in 2009, grazed by cattle (IP). Results have shown that herbaceous biomass productivity was on average 8 times higher in IP than in the NU most likely due to the positive effects of the initial fertilization and the legume rich seed composition which increased N soil availability. The main climatic driver explaining the biomass productivity was the cumulative precipitation from February to May. The proportion of grasses increased in response to drought with a pronounce decrease in legumes, regardless of the management system. Nonetheless, the NU system was more resilient to drought compared to IP suggesting a need to better understand the role and contribution of each native species to resistance, resilience and recovery to drought in order to improve future forage mixtures. These results may support better management decisions by forest producers which are mostly based on empirical procedures and might provide some directions for further studies. [ABSTRACT FROM AUTHOR]

Electron-driven reactions of CF 3 CH 2 F have been studied focusing on the formation of the parent cation, CF 3 + and CH 2 F + (C–C bond cleavage) fragments as a function of the electron energy. For the three referred cations, an unpredicted shoulder structure is observed in the ion yield between 12 and 20 eV, indicating a resonant process (electron attachment). Viewing the observations as the result of a competition between the expected dissociative electron ionization and a dissociative electron attachment, we propose a new route where the formation of the transient anion, under two autodetachments, ultimately triggers the formation of positively charged fragments. The reaction e - + AB → AB - ∗ → AB ∗ + e - → A + + B + 2 e - is supported by both experimental data and scattering calculations. [ABSTRACT FROM AUTHOR]

The Altitudinal Atlantic Forest is comprised of humid forest enclaves on top of the mountains surrounded by the Caatinga's xeric shrubland vegetation. It is considered a humidity refuge of endemism in semi-arid regions, and it is under intense anthropogenic pressure. Dung beetle communities are widely used as an ecological indicator of environmental conservation. However, dung beetle communities of the Altitudinal Atlantic Forest are poorly studied, and their value for biodiversity conservation in semi-arid regions is unknown. We describe and compare dung beetle communities of Altitudinal Atlantic Forest remnants located in the Brazilian Northeast semi-arid region to evaluate whether diversity patterns and species composition differ among the remnants. We captured 1,333 beetles belonging to 24 species. Only one remnant showed a statistically significant difference in diversity based on species richness and abundance, and beta diversity showed a high dissimilarity among remnants. The remnants had in common only one species, and the dominant species were distinct among them. Species composition was 16% similar among the sampled remnants, and we registered species commonly found in the Atlantic Forest, the Caatinga, and Amazonia. The structure of the dung beetle community in each remnant could be related to the historical origin and maintenance of the Altitudinal Atlantic Forest. Species compositions changed as a result of geographic location and surrounding environments, which act as filters to dung beetle species flow and establishment. We highlight the importance of the Altitudinal Atlantic Forest for the conservation and maintenance of biodiversity in the semi-arid region. [ABSTRACT FROM AUTHOR]

The low velocity impact response of the epoxy composite materials, which were reinforced with various hybrid contents, such as plain pure or hybrid fabrics (carbon, aramid and glass fibers and copper wires) and filler mixtures into the epoxy matrix (aramid powder, potatoes starch, barium ferrite and carbon black) was investigated using a drop weight impact machine. The aim of this study was to characterize and assess the effects of fiber orientation at various angles and filler mixtures into epoxy matrix on the impact response. All the tests were carried out at constant impact energy, namely 90.629 J. Results indicated that the fiber orientation at various angles has a positive effect on impact response, mainly in the case of aramid fabric reinforced composites. In terms of influence of fillers addition into matrix, it was obtained an improvement on the impact response of hybrid fabric reinforced composite as compared to the pure fabric reinforced composites. [ABSTRACT FROM AUTHOR]

Marine sponges from the Plakinidae family are well known for hosting cytotoxic secondary metabolites and the Brazilian Atlantic coast and its oceanic islands have been considered as a hotspot for the discovery of new Plakinidae species. Herein, we report the chemical profile among cytotoxic extracts obtained from four species of Plakinidae, collected in Fernando de Noronha Archipelago (PE, Northeastern Brazil). Crude organic extracts of Plakinastrella microspiculifera, Plakortis angulospiculatus, Plakortis insularis, and Plakortis petrupaulensis showed strong antiproliferative effects against two different cancer cell lines (HCT-116: 86.7–100%; MCF-7: 74.9–89.5%) at 50 μg/mL, by the MTT assay. However, at a lower concentration (5 μg/mL), high variability in inhibition of cell growth was observed (HCT-116: 17.3–68.7%; MCF-7: 0.00–55.5%), even within two samples of Plakortis insularis which were collected in the west and east sides of the Archipelago. To discriminate the chemical profile, the samples were investigated by UHPLC-HRMS under positive ionization mode. The produced data was uploaded to the Global Natural Products Social Molecular Networking and organized based on spectral similarities for purposes of comparison and annotation. Compounds such as dipeptides, nucleosides and derivatives, polyketides, and thiazine alkaloids were annotated and metabolomic differences were perceived among the species. To the best of our knowledge, this is the first assessment for cytotoxic activity and chemical profiling for Plakinastrella microspiculifera, Plakortis insularis and Plakortis petrupaulensis, revealing other biotechnologically relevant members of the Plakinidae family. [ABSTRACT FROM AUTHOR]

This paper investigates whether the framework of fractional quantum mechanics can broaden our perspective of black hole thermodynamics. Concretely, we employ a space-fractional derivative (Riesz in Acta Math 81:1, 1949) as our main tool. Moreover, we restrict our analysis to the case of a Schwarzschild configuration. From a subsequently modified Wheeler–DeWitt equation, we retrieve the corresponding expressions for specific observables. Namely, the black hole mass spectrum, M, its temperature T, and entropy, S. We find that these bear consequential alterations conveyed through a fractional parameter, α . In particular, the standard results are recovered in the specific limit α = 2 . Furthermore, we elaborate how generalizations of the entropy-area relation suggested by Tsallis and Cirto (Eur Phys J C 73:2487, 2013) and Barrow (Phys Lett B 808:135643, 2020) acquire a complementary interpretation in terms of a fractional point of view. A thorough discussion of our results is presented. [ABSTRACT FROM AUTHOR]

Holothuria arguinensis, Holothuria mammata and Holothuria forskali are three common sea cucumber species found in the NE Atlantic, traded in international markets and susceptible to capture. Allometric relationships reveal if the scaling relationships between biometric characters are proportional with growth, being a useful tool to understand species growth strategies. Allometric relationships of the three species were estimated and compared between them and with populations from different regions. These allometric relationships revealed that the three species have negative allometric growth. However, they have different growth strategies between them and reveal different regional intra-specific growth strategies when compared to other populations, suggesting ontogenetic adaptation as a consequence of external factors. [ABSTRACT FROM AUTHOR]

Transformer insulation aging is a critical issue for both reliable and economic operations, and for planning of electrical systems. As insulation aging depends on the hottest-spot temperature, transformer management can be improved with a suitable model for temperature estimation and prediction. However, the temperature inside transformers varies dynamically because of changes in both the cooling conditions and the load cycles. Hence, this paper presents an algorithm to estimate and predict the hottest-spot in dry-type distribution transformers, so that their capability and insulation life can be assessed. This procedure is focused on transformers used to directly connect PV-inverters to the grid in order to consider the uncontrolled power generation of distribution PV-systems. To implement the algorithm, it is assumed that records of ambient temperature, PV-system power generation cycle and winding temperature are available. With these data, the parameters of an equivalent thermal circuit are fitted in order to dynamically model the transformer hottest-spot. The method was validated using twelve-day records of a 70 kW p PV-generation system connected to a 75 kVA dry-type transformer. Results show that an enhancement in the hot-spot estimation is reached, and an assessment of the performance in real-time monitoring of the transformer capacity is achieved employing the proposed algorithm. [ABSTRACT FROM AUTHOR]

Exchange bias properties of MnFe 2 O 4 @ γ –Fe 2 O 3 core–shell nanoparticles are investigated. The measured field and temperature dependencies of the magnetization point out a well-ordered ferrimagnetic core surrounded by a layer with spin glass-like arrangement. Quasi-static SQUID magnetization measurements are presented along with high-amplitude pulse ones and are cross-analyzed by comparison against ferromagnetic resonance experiments at 9 GHz. These measurements allow one to discern three types of magnetic anisotropies affecting the dynamics of the magnetic moment of the well-ordered ferrimagnetic NP's core viz. the easy-axis (uniaxial) anisotropy, the unidirectional exchange-bias anisotropy and the rotatable anisotropy. The uniaxial anisotropy originates from the structural core–shell interface. The unidirectional exchange-bias anisotropy is associated with the spin-coupling at the ferrimagnetic/spin glass-like interface; it is observable only at low temperatures after a field-cooling process. The rotatable anisotropy is caused by partially-pinned spins at the core/shell interface; it manifests itself as an intrinsic field always parallel to the external applied magnetic field. The whole set of experimental results is interpreted in the framework of superparamagnetic theory, i.e., essentially taking into account the effect of thermal fluctuations on the magnetic moment of the particle core. In particular, it is found that the rotatable anisotropy of our system is of a uniaxial type. [ABSTRACT FROM AUTHOR]

Biomass burning in the Brazilian Amazon is modulated by climate factors, such as droughts, and by human factors, such as deforestation, and land management activities. The increase in forest fires during drought years has led to the hypothesis that fire activity decoupled from deforestation during the twenty-first century. However, assessment of the hypothesis relied on an incorrect active fire dataset, which led to an underestimation of the decreasing trend in fire activity and to an inflated rank for year 2015 in terms of active fire counts. The recent correction of that database warrants a reassessment of the relationships between deforestation and fire. Contrasting with earlier findings, we show that the exacerbating effect of drought on fire season severity did not increase from 2003 to 2015 and that the record-breaking dry conditions of 2015 had the least impact on fire season of all twenty-first century severe droughts. Overall, our results for the same period used in the study that originated the fire-deforestation decoupling hypothesis (2003–2015) show that decoupling was clearly weaker than initially proposed. Extension of the study period up to 2019, and novel analysis of trends in fire types and fire intensity strengthened this conclusion. Therefore, the role of deforestation as a driver of fire activity in the region should not be underestimated and must be taken into account when implementing measures to protect the Amazon forest. [ABSTRACT FROM AUTHOR]

Despite significant research advances on the seismic response analysis, there is still an urgent need for validation of numerical simulation methods for prediction of earthquake response and damage. In this respect, seismic monitoring networks and proper modelling can further support validation studies, allowing more realistic simulations of what earthquakes can produce. This paper discusses the seismic response of the "Pietro Capuzi" school in Visso, a village located in the Marche region (Italy) that was severely damaged by the 2016–2017 Central Italy earthquake sequence. The school was a two-story masonry structure founded on simple enlargements of its load-bearing walls, partially embedded in the alluvial loose soils of the Nera river. The structure was monitored as a strategic building by the Italian Seismic Observatory of Structures (OSS), which provided acceleration records under both ambient noise and the three mainshocks of the seismic sequence. The evolution of the damage pattern following each one of the three mainshocks was provided by on-site survey integrated by OSS data. Data on the dynamic soil properties was available from the seismic microzonation study of the Visso village and proved useful in the development of a reliable geotechnical model of the subsoil. The equivalent frame (EF) approach was adopted to simulate the nonlinear response of the school building through both fixed-base and compliant-base models, to assess the likely influence of soil–structure interaction on the building performance. The ambient noise records allowed for an accurate calibration of the soil–structure model. The seismic response of the masonry building to the whole sequence of the three mainshocks was then simulated by nonlinear time history analyses by using the horizontal accelerations recorded at the underground floor as input motions. Numerical results are validated against the evidence on structural response in terms of both incremental damage and global shear force–displacement relationships. The comparisons are satisfactory, corroborating the reliability of the compliant-base approach as applied to the EF model and its computational efficiency to simulate the soil–foundation–structure interaction in the case of masonry buildings. [ABSTRACT FROM AUTHOR]

The number of patients undergoing joint replacement surgery has progressively increased worldwide due to world population ageing. In the Unites States, for example, the prevalence of hip and knee replacements has increased more than 6 and 10 times, respectively, since 1980. Despite advances in orthopaedic implant research, including the development of novel implantable biomaterials, failures are still observed due to inadequate biomechanical compliance at the bone-implant interface. This comprises static and dynamic mechanical mismatch between the bone and the implant surface. The importance and robustness of biomechanical cues for controlling osteogenic differentiation of mesenchymal stem cells (MSC) have been highlighted in recent studies. However, in the context of bone regenerative medicine, it remains elusive how mechanobiological signals controlling MSC osteogenic differentiation dynamics are modulated in their interaction with the bone and with implants. In this review, we highlight recent technological advances aiming to improve host bone-implant interactions based on the osteogenic and mechanoresponsive potential of MSC, in the context of joint replacement surgery. First, we discuss the extracellular and intracellular mechanical forces underlying proper receptivity and stimulation of physiological MSC differentiation and linked osteogenic activity. Second, we provide a critical overview on how this knowledge can be integrated towards the development of biomaterials for improved bone-implant interfaces. Third, we discuss cross-disciplinarily which contributes to the next generation design of novel pro-active orthopaedic implants and their implantation success. [ABSTRACT FROM AUTHOR]

The paper presents the results of 5 case studies on complex site effects selected within the project for the level 3 seismic microzonation of several municipalities of Central Italy damaged by the 2016 seismic sequence. The case studies are characterized by different geological and morphological configurations: Monte San Martino is located along a hill slope, Montedinove and Arquata del Tronto villages are located at ridge top whereas Capitignano and Norcia lie in correspondence of sediment-filled valleys. Peculiarities of the sites are constituted by the presence of weathered/jointed rock mass, fault zone, shear wave velocity inversion, complex surface and buried morphologies. These factors make the definition of the subsoil model and the evaluation of the local response particularly complex and difficult to ascertain. For each site, after the discussion of the subsoil model, the results of site response numerical analyses are presented in terms of amplification factors and acceleration response spectra in selected points. The physical phenomena governing the site response have also been investigated at each site by comparing 1D and 2D numerical analyses. Implications are deduced for seismic microzonation studies in similar geological and morphological conditions. [ABSTRACT FROM AUTHOR]

α-Ag2WO4 nanocrystals, mesoporous silica (SBA-15), and α-Ag2WO4/SBA-15 as a nanocomposite were prepared by sonochemical, hydrothermal, and in situ sonochemical methods respectively. Samples were characterized by X-ray diffraction (XRD), Rietveld refinement, micro-Raman, Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption, ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy, and Zeta potential. XRD patterns, Rietveld refinement, and XPS spectra confirmed the formation of α-Ag2WO4, SBA-15, and α-Ag2WO4/SBA-15. XPS spectra evidenced the formation of metallic silver during analysis. FE-SEM images illustrated the deposition of α-Ag2WO4 nanocrystals mainly on the external surface of SBA-15. N2 adsorption data showed that the textural properties of α-Ag2WO4/SBA-15 were similar to pure SBA-15. Zeta potential data demonstrated that all samples synthetized have negatively charged surface. The materials were tested as adsorbents for the dye cationic rhodamine B. The adsorption behavior of rhodamine B onto α-Ag2WO4, SBA-15, and α-Ag2WO4/SBA-15 correspond to Langmuir adsorption isotherm and pseudo-second-order kinetics. The maximum adsorption capacity of α-Ag2WO4/SBA-15 was up to 150 mg g−1 and 99% removal efficiency for RhB 20 mg L−1 in 15 min. Furthermore, 80% of RhB could be recuperated from adsorbents at pH 7. [ABSTRACT FROM AUTHOR]

Neoadjuvant chemotherapy has been established as the standard of care for HER2-positive breast cancer since it allows cancer down-staging, up to pathological complete response. The standard of care in the neoadjuvant setting for HER2-positive breast cancer is a combination of highly cytotoxic drugs such as anthracyclines and the anti-HER2 monoclonal antibody. Despite this cocktail allows a pathological complete response in up to 50%, their co-administration is strongly limited by intrinsic cardiotoxicity. Therefore, only a sequential administration of anthracyclines and the anti-HER2 treatment is allowed. Here, we propose the anthracycline formulation in H-Ferritin nanocages as promising candidate to solve this unmet clinical need, thanks to its capability to increase anthracyclines efficacy while reducing their cardiotoxicity. Treating a murine model of HER2-positive breast cancer with co-administration of Trastuzumab and H-Ferritin anthracycline nanoformulation, we demonstrate an improved tumor penetration of drugs, leading to increased anticancer efficacy and reduced of cardiotoxicity. [ABSTRACT FROM AUTHOR]

The corrosion of AA 7075-T6 aluminum alloy is a critical issue for many industries. In this study, aluminum coatings were deposited onto AA 7075-T6 by cold gas spray and the effect of the porous outer layer on different properties of the coating, including corrosion–resistance was investigated. As-prepared and polished samples were used to study the microstructure, morphology, mechanical properties and corrosion resistance of the coating in 3.5 wt.% NaCl solution. Cross-sectional analysis showed a dense structure, low porosity (0.8%) and thickness up to 300 µm (~ 100 µm for the porous outer layer and ~ 200 µm for the compact inner layer). The sliding wear test resulted in a volume loss of 3.2 × 10−4 mm3/Nm with an adhesive wear mechanism. The abrasive wear test showed a wear rate of 1.1 × 10−4 mm3/Nm for the as-prepared coating and 0.8 × 10−4 mm3/Nm for the polished coating. The as-prepared coating pores and interparticle spacing in the outer layer were mostly responsible for the increase in wear rate. For the polished coating immersed in 3.5 wt.% NaCl solution during 900 h, the electrolyte reached some specific points of the substrate as revealed by the cross-sectional analysis. Inspection of the as-prepared coating demonstrated that the coating/substrate interface was completely damaged after long immersion times (~ 900 h). [ABSTRACT FROM AUTHOR]

This work discusses the effects of soluble mineral salts on ceramic brick masonry walls at Petrolina, Pernambuco, Brazil, located 780 km from the ocean. To understand this phenomenon, a mapping of the pathologies originating from the effects of soluble mineral salts in Petrolina was carried out and wells were implemented to monitor the underground water supply in five points considered to be where the most frequent occurrence of the phenomenon takes place. Samples of soil, groundwater, bricks affected by the phenomenon and the level of chloride in the atmosphere of these localities were collected and analysed in the laboratory in order to characterize their properties. The results obtained indicate that the building pathological manifestations present in ceramic block walls, located in the study areas, are strongly correlated with the high content of soluble salts observed in the soil and groundwater samples collected than by the amount of chloride content in the atmosphere soluble salt levels. Clay sands are a type of soil more prone to underground water runoff and, because of this feature, provide a more favourable environment for rising moisture that transports soluble mineral salts to the masonry walls accelerating their degradation process. [ABSTRACT FROM AUTHOR]

Nowadays, boron nitride has attracted a great deal of attention due to its physical (chemical) properties, facile synthesis, and experimental characterization, indicating great potential for industrial application. Based on this, we develop here a theoretical study on boron nitride nanoflakes built-up from hexagonal boron nitride nanosheets exhibiting hexagonal, rectangular, and triangular shapes. In order to investigate geometry effects such as those due to the presence of armchair and zigzag edges and distinct shapes, we analyzed their properties from both classical and quantum viewpoints. Using classical molecular dynamics calculations, we show that the nanosheets preserve their structural stability at high temperatures, while DFT calculations demonstrate HOMO–LUMO energy gap variation within the theoretical energy gaps of h-BN in bulk and 2D crystals. Besides that, we have also found that boron nitride nanoflakes structures have spatially symmetrical spin densities. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the role of different welding techniques: laser and tungsten inert gas (TIG) on the corrosion behavior of commercially pure titanium (cp-Ti) frameworks in dentistry. Electrochemical tests were conducted in artificial saliva at pH 7.2, 37°C. The surfaces were examined using scanning electron microscopy. The received data were analyzed by one-way ANOVA followed by Tukey's test for multiple comparisons (α = 0.05). Cp-Ti frameworks welded by TIG were found to be more susceptible to corrosion, where defects in the weld region appeared to be the most important factor for the corrosion behavior. These findings suggested a better corrosion behavior for the laser welding procedure. [ABSTRACT FROM AUTHOR]