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The following review article attempts to compare the antioxidant activity of the compounds. For this purpose, density functional theory/Becke three-parameter Lee–Yang–Parr (DFT/B3LYP) methodology was carried out instead of using pharmacological methodologies because of economic benefits and high accuracy. This methodology filtrates the compounds with the lowest antioxidant activity. At first, the Koopmans’ theorem was carried out to calculate some descriptors to compare antioxidants. The energy of the highest occupied molecular orbitals (HOMO) was accepted as the best indicator, and then some studies confirmed that the highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO–LUMO) energy gap is the more precise descriptor. Although it would be better to compare spin density distribution (SDD) on the oxygen of the corresponding radical in the polarizable continuum model (PCM) to evaluate their capability to chain reaction inhibition. Next, it was mentioned that in the multi-target directed ligands (MTDLs), the antioxidant is connected to other moieties in para positions to create better antioxidants or novel hybrid compounds. Indeed, SDD was introduced as a descriptor for MTDL antioxidant effectiveness. Then, the relation between antioxidants and aromaticity was investigated. The more the aromaticity of an antioxidant, the more stable the corresponding radical is. Subsequently, in preferred antioxidant activity, it was defined that the hydrogen atom transfer (HAT) mechanism is more favored in metabolism phase I. It has been seen that the solvent model can change the antioxidant mechanism. Therefore, the solvent model is more important than the chemical structure of antioxidants, and an ideal antioxidant should be evaluated in PCM for pharmacological evaluations.

We present a newly developed empirical model of the plasma density in the plasmasphere. It is based on more than 700 density profiles along field lines derived from active sounding measurements made by the radio plasma imager on IMAGE between June 2000 and July 2005. The measurements cover all magnetic local times and vary from L = 1.6 to L = 4 spatially, with every case manually confirmed to be within the plasmasphere by studying the corresponding dynamic spectrogram. The resulting model depends not only on L‐shell but also on magnetic latitude and can be applied to specify the electron densities in the plasmasphere between 2000 km altitude and the plasmapause (the plasmapause location itself is not included in this model). It consists of two parts: the equatorial density, which falls off exponentially as a function of L‐shell; and the field‐aligned dependence on magnetic latitude and L‐shell (in the form of invariant magnetic latitude). The fluctuations of density appear to be greater than what could be explained by a possible dependence on magnetic local time or season, and the dependence on geomagnetic activity is weak and cannot be discerned. The solar cycle effect is not included because the database covers only a fraction of a solar cycle. The performance of the model is evaluated by comparison to four previously developed plasmaspheric models and is further tested against the in situ passive IMAGE RPI measurements of the upper hybrid resonance frequency. While the equatorial densities of different models are mostly within the statistical uncertainties (especially at distances greater than L = 3), the clear latitudinal dependence of the RPI model presents an improvement over previous models. The model shows that the field‐aligned density distribution can be treated neither as constant nor as a simple diffusive equilibrium distribution profile. This electron density model combined with an assumed model of the ion composition can be used to estimate the time for an Alfven wave to propagate from one hemisphere to the other, to determine the plasma frequencies along a field line, and to calculate the raypaths for high frequency waves propagating in the plasmasphere. Key Points Improved empirical model of the Earth's plasmasphere Realistic description of the field‐aligned electron density distribution Possible applications in studies of the inner magnetosphere and wave propagation

The mechanical quality of trabecular bone is influenced by its mineral content and spatial distribution, which is controlled by bone remodelling and mineralisation. Mineralisation kinetics occur in two phases: a fast primary mineralisation and a secondary mineralisation that can last from several months to years. Variations in bone turnover and mineralisation kinetics can be observed in the bone mineral density distribution (BMDD). Here, we propose a statistical spatio-temporal bone remodelling model to study the effects of bone turnover (associated with the activation frequency Ac . f ) and mineralisation kinetics (associated with secondary mineralisation T sec ) on BMDD. In this model, individual basic multicellular units (BMUs) are activated discretely on trabecular surfaces that undergo typical bone remodelling periods. Our results highlight that trabecular BMDD is strongly regulated by Ac . f and T sec in a coupled way. Ca wt% increases with lower Ac . f and short T sec . For example, a Ac . f = 4 BMU/year/mm 3 and T sec = 8 years result in a mean Ca wt% of 25, which is in accordance with Ca wt% values reported in quantitative backscattered electron imaging (qBEI) experiments. However, for lower Ac . f and shorter T sec (from 0.5 to 4 years) one obtains a high Ca wt% and a very narrow skew BMDD to the right. This close link between Ac . f and T sec highlights the importance of considering both characteristics to draw meaningful conclusion about bone quality. Overall, this model represents a new approach to modelling healthy and diseased bone and can aid in developing deeper insights into disease states like osteoporosis.

Even though information on global biodiversity trends becomes increasingly available, large taxonomic and spatial data gaps persist at the scale relevant to planning conservation interventions. This is because data collectors are hesitant to share data with global repositories due to workload, lack of incentives, and perceived risk of losing intellectual property rights. In contrast, due to greater conceptual and methodological proximity, taxon-specific database initiatives can provide more direct benefits to data collectors through research collaborations and shared authorship. The IUCN SSC Ape Populations, Environments and Surveys (A.P.E.S.) database was created in 2005 as a repository for data on great apes and other primate taxa. It aims to acquire field survey data and make different types of data accessible, and provide up-to-date species status information. To support the current update of the conservation action plan for western chimpanzees (Pan troglodytes verus) we compiled field surveys for this taxon from IUCN SSC A.P.E.S., 75% of which were unpublished. We used spatial modeling to infer total population size, range-wide density distribution, population connectivity and landscape-scale metrics. We estimated a total abundance of 52 800 (95% CI 17 577-96 564) western chimpanzees, of which only 17% occurred in national parks. We also found that 10% of chimpanzees live within 25 km of four multi-national 'development corridors' currently planned for West Africa. These large infrastructure projects aim to promote economic integration and agriculture expansion, but are likely to cause further habitat loss and reduce population connectivity. We close by demonstrating the wealth of conservation-relevant information derivable from a taxon-specific database like IUCN SSC A.P.E.S. and propose that a network of many more such databases could be created to provide the essential information to conservation that can neither be supplied by one-off projects nor by global repositories, and thus are highly complementary to existing initiatives.

Estimating and mapping population distributions dynamically at a city-wide spatial scale, including those covering suburban areas, has profound, practical, applications such as urban and transportation planning, public safety warning, disaster impact assessment and epidemiological modelling, which benefits governments, merchants and citizens. More recently, call detail record (CDR) of mobile phone data has been used to estimate human population distributions. However, there is a key challenge that the accuracy of such a method is difficult to validate because there is no ground truth data for the dynamic population density distribution in time scales such as hourly. In this study, we present a simple and accurate method to generate more finely grained temporal-spatial population density distributions based upon CDR data. We designed an experiment to test our method based upon the use of a deep convolutional generative adversarial network (DCGAN). In this experiment, the highest spatial resolution of every grid cell is 125125 square metre, while the temporal resolution can vary from minutes to hours with varying accuracy. To demonstrate our method, we present an application of how to map the estimated population density distribution dynamically for CDR big data from Beijing, choosing a half hour as the temporal resolution. Finally, in order to cross-check previous studies that claim the population distribution at nighttime (from 8 p.m. to 8 a.m. on the next day) mapped by Beijing census data are similar to the ground truth data, we estimated the baseline distribution, first, based upon records in CDRs. Second, we estimate a baseline distribution based upon Global Navigation Satellite System (GNSS) data. The results also show the Root Mean Square Error (RMSE) is about 5000 while the two baseline distributions mentioned above have an RMSE of over 13,500. Our estimation method provides a fast and simple process to map people’s actual density distributions at a more finely grained, i.e., hourly, temporal resolution.

In this research work, BaZr 0.85 Ho 0.10 Y 0.025 Nd 0.025 O 3-δ (BZHYN) electrolyte ceramic was synthesized through a cost-effective flash pyrolysis route followed by conventional sintering for intermediate-temperature solid oxide fuel cells. The calcined powder and sintered pellet were characterized through various techniques like high-resolution X-ray diffraction (HRXRD), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), and Raman spectroscopy. The HRXRD pattern of calcined and sintered pellet shows the pure cubic phase with P m 3 ¯ m space group symmetry through the Rietveld refinement. The study of the electron-density distribution of calcined powder and sintered pellet calculated by the maximum entropy method reveals the presence of oxygen vacancies at the octahedral site in the sintered sample. The microstructure of the fracture surface of the sintered sample indicates two types of grain with a relative density of 93.7% through FESEM. The Raman analysis confirms the distortion along the c-axis and oxygen vacancies in the octahedral site of BZHYN ceramic. Impedance spectroscopy measurement was conducted in the temperature range of 50 to 700 °C and frequency range of 1 Hz to 10 MHz. The Nyquist plots obtained in the temperature range of 350–700 °C reveal three distinct relaxation processes attributed to grain, grain boundary, and electrode effect. The temperature-dependent exponent (n) associated with grain and grain boundary decreases with the increase in temperature, indicating that large polaron hopping is involved in the electrical conduction mechanism.

The abundance of low-density species like carnivores is logistically difficult to directly estimate at a meaningful scale. Predictive distribution models are often used as a surrogate for density estimation. But because density can continue to increase as occupancy asymptotes at 1, occupancy may have little value as an index, and home range expansion in marginal habitat may further confound the association. We sought to estimate bobcat population size at a landscape scale (14,286 km2) in central Wisconsin, which provided an opportunity to relate predicted occurrence to individual space use and population density. We sampled bobcats using motion-sensitive trail cameras at 9 arrays across central Wisconsin. We estimated bobcat site-specific occupancy, and regressed these estimates as linear or asymptotic functions of site-specific density to determine the strength and shape of their association. We subsequently modeled both parameters relative to habitat covariates and repeated the regression process. A linear functional relationship between density and occupancy was most supported when detection parameters were held constant (wi=0.97, R2 = 0.72) and when detection, occurrence, and density were modeled as a function of habitat covariates (wi=0.99, R2 = 0.95). This suggests that repeated presence-absence data alone may be an efficient and reliable method for inferring spatial patterns in bobcat density or identifying habitat types with greater density potential in the northern parts of its range. Bobcat occupancy and density were both positively associated with surrounding woody cover and wetland edge density. Our most supported spatially explicit capture-recapture model estimated bobcat abundance as 362 adult individuals (95% CI 272–490) across the study area. © 2015 The Wildlife Society.

Welding fault detection in the industry of hot water tanks remains typically conducted visually or with the assistance of None Destructive Examination, such as X-ray, ultrasound, and penetrant testing. However, this leads to high consumption of time and resources. We propose in this paper a two-level method for automatic welding defect detection and localization. The method is based on the classification of the probability density distributions of the voltage signals underlying the generated stochastic process from the welding operation. In the main phase, we apply a passband filter to the raw signals and use the Kernel Density Estimation to measure the distribution of the filtered signal. The probability density distributions are processed as functional data and classified employing a functional non-parametric kernel classifier. In the second phase, the signal of nonconforming welding is split into segments and their probability density distributions are classified in order to extract the precise location of the defect in the whole signal. The proposed method allows to detect and localize welding defects with high accuracy.

Bamboo fiber composite (BFC) is a unidirectional and continuous bamboo fiber composite manufactured by consolidation and gluing of flattened, partially separated bamboo culm strips into thick and dense panels. The composite mechanical properties are primarily influenced by panel density, its variation and uniformity. This paper characterized the horizontal density distribution (HDD) within BFC panels and its controlling factors. It revealed that HDD follows a normal distribution, with its standard deviation (SD) strongly affected by sampling specimen size, panel thickness and panel locations. SD was lowest in the thickest (40 mm) panel and largest-size (150 × 150-mm2) specimens. There was also a systematic variation along the length of the BFC due to the tapering effect of bamboo culm thickness. Density was higher along panel edges due to restraint from the mold edges during hot pressing. The manual BFC mat forming process is presented and found to effectively minimize the density variation compared to machine-formed wood composites. This study provides a basic understanding of and a quality control guide to the formation uniformity of BFC products.

Bulk heterojunction (BHJ) organic solar cells (OSCs) represent a class of thin-film photovoltaic devices that harness the unique properties of organic semiconductors. Despite remarkable progress, BHJ OSCs still face challenges related to stability, scalability, and long-term performance. This paper presents a thorough and comprehensive computational exploration of the potential viability of tetraazapentacene (TAP) as an active material in BHJ solar cells, utilizing a synergistic approach that combines density functional theory (DFT) and TD-DFT calculations. Our study is centered on investigating the impact of molecular modifications by exchanging CH with nitrogen in the pentacene framework on the overall performance as well as electrical and optoelectronic properties. This approach provides meaningful design recommendations for TAP's usage in OSC applications. The series of TAP structures (with and without inversion symmetry) were analyzed to see the effect of nitrogen incorporation on energy levels, bandgap, reorganization energy, electron and hole delocalization, charge transfer, and charge carrier mobility. Our findings, as revealed by the electron density distribution map, electron delocalization analysis e.g., electron localization function, local orbital locator, transition density matrix, and frontier molecular orbital analysis, suggest that the TAP may allow easier electron injection owing to its lower LUMO level and high EA value. TDM analysis reveals that TAPs lacking inversion symmetry exhibit higher electron–hole coherence across the structure, resulting in efficient electron transport. Applying the Scharber model formalism and utilizing TAPs as donors and PCBM as acceptors in BHJ solar cells, the power conversion efficiency was estimated to be approximately ~ 28%. Graphical abstract This study explores the potential of Tetraazapentacene (TAP) as an active material in bulk heterojunction (BHJ) organic solar cells through Density Functional Theory (DFT) and TD-DFT analyses. By substituting CH groups with nitrogen in the pentacene framework, the impact on optoelectronic and electrical properties is examined. TAP structures lacking inversion symmetry demonstrate enhanced electron delocalization, increased electron affinity, and stronger electron–hole coherence, which collectively improve electron transport. Utilizing the Scharber model, with TAP as the donor and PCBM as the acceptor, the estimated power conversion efficiency (PCE) reaches approximately 28%.