Absorption of gamma-emitting fission products and activation products by rice under flooded and unflooded conditions from two tropical soils

The absorption of gamma-emitting fission products 106Ru,125Sb,137Cs and144Ce and activation products59Fe,58Co.54Mn and65Zn by rice plants grown on two contrasting tropical soils, namely, a blak soil (pellustert) and a laterite (oxisol), and the effects of flooding were studied under controlled conditions. Results indicated greater uptake of 106Ru and 125Sb from the black soil than from the laterite. In contrast, the uptake of 144Ce and 137Cs was greater in the laterite than in the black soil. Flooding treatment enhanced the uptake of all these fission products by rice plants in the laterite soil whereas this effect was observed only for 125Sb and 137Cs in the black soil. The plant uptake of activation products from the two soil types showed maximum accumulation of 65Zn followed by 54Mn,59Fe and 58Co in both soil types. Besides, uptake of these nuclides was greater from the laterite soil than from the black soil. Flooding treatment for rice while showing a reduction of 59Fe uptake, showed an increase in plant uptake of 58Co,54Mn and 65Zn in both soil types

Population-weighted degree-days: The global shift between heating and cooling

Anthropogenic greenhouse gas emissions are driving global increases in temperature. This rise will likely lead to an increase in demand for cooling in the coming years. However, increasing temperatures are not the main explanatory factor for why the world is moving towards more cooling. This paper compares population and area-weighted cooling and heating degree-days derived using ERA5-Land reanalysis temperature, to show that population growth in warmer parts of the world drives cooling demand globally. The analysis shows that mean global area-weighted heating degree-days have fallen 8.46 °C days/year, whereas population-weighted heating degree-days have fallen by 12.5 °C days/year. At the same time, mean global area-weighted cooling degree-days have risen by 3.0 °C days/year, while population-weighted cooling degree-days have risen at 6.0 °C days/year. By using sub-country analysis, this paper shows that population-weighted degree-days can substantially differ from area-weighted degree-days. Finally, the findings highlight that the choice of heating and cooling degree-day base temperature is the most important parameter in the variability of degree-days and will need to be understood better in order to accurately account for future heating and cooling energy demand

Asphericity Can Cause Nonuniform Lithium Intercalation in Battery Active Particles

Uniform intercalation is desired to enable next-generation Li-ion batteries. While we expect nonuniformity in materials undergoing a phase change, single-phase intercalation materials such as nickel manganese cobalt oxide are believed to lithiate uniformly at the particle/electrolyte interface. However, recent imaging reveals nonuniform lithiation. Motivated by this discrepancy, we examine if aspherical particle shape can cause such nonuniformity since the conventional belief is based on spherical particle theory. We obtain real particle geometries using rapid lab-based X-ray computed tomography and subsequently perform physics-based calculations accounting for electrochemical reactions at the particle/electrolyte interface and lithium transport inside the particle bulk. The aspherical geometry breaks the symmetry and causes nonuniform reaction distribution. Such nonuniformity is exacerbated as the particle becomes more aspherical. The proposed mechanism represents a fundamental limit on achievable lithiation uniformity in aspherical particles in the absence of other mechanisms causing inhomogeneity, such as grain structure, nonuniform carbon-binder coating, etc

Abusive supervision in commercial kitchens:Insights from the restaurant industry

This mixed-method study investigates how abusive supervision and bullying impact job satisfaction and turnover intentions among employees in an environment plagued by ingrained incivility: commercial kitchens. Underpinned by social learning theory, we draw from 832 survey responses and 20 in-depth interviews to explore the extent to which supervisory abuse and workplace bullying negatively impact employee perceptions of their working environment while also investigating positive alternatives therein (e.g., authentic leadership and encouragement of creativity). Results suggest that, despite day-to-day challenges posed by abusive leadership, a strong sense of camaraderie and passion for kitchen work stimulated a commitment to the job. Accordingly, the study concludes that the inherently creative nature of commercial kitchen work and the personalities of fellow staff played a significant role in retaining employees. It thus highlights the complexity of food service employee retention and suggests that a holistic understanding of both leadership dynamics and intrinsic motives is essential

A Snapshot of Chemistry Teaching and Learning Practices in UK Higher Education as It Emerges from the COVID-19 Pandemic

The start of the COVID-19 pandemic saw a change in the way chemistry education was delivered across the globe. As we emerge from the pandemic we can start to assess the medium to long-term impact it has had. In this study, we evaluated the teaching methods used by the UK Higher Education chemistry community over the past two years through the perspectives of students and instructors at UK institutions. We report how online and face-to-face teaching methods have evolved for both the teaching of chemical theory and practical work. We also present insights from instructors and students on how teaching through the pandemic has impacted their perception of students grades, knowledge, skills, and future plans

Origin of trap assisted tunnelling in ammonia annealed SiC trench MOSFETs

The interface between silicon carbide (SiC) and silicon dioxide (SiO2) is of considerable importance for the performance and reliability of 4H-SiC (trench) metal oxide semiconductor field effect transistors (MOSFETs) and various different post oxidation anneals (POAs) have been used to optimize its quality. Whereas nitric oxide (NO) POA leads to very reliable and well performing MOSFETs, ammonia (NH3) can further improve the device performance, however, at the cost of the gate oxide (GOX) reliability, e.g. leading to trap assisted tunneling (TAT). We investigate the origin of TAT and GOX leakage in differently annealed gate oxides experimentally, using 4H-SiC trench MOSFETs, and theoretically, using Density Functional Theory (DFT) simulations. Our findings reinforce the view that the NO anneal for SiC devices results in the best overall quality as devices annealed in NH3 and nitrogen N2 show higher oxide charge density and leakage currents. DFT simulations demonstrate that, contrary to what has often been assumed so far, NH3 annealing leads to the formation of additional hydrogen related defects, which open leakage paths in the oxide otherwise not present in NO treated oxides

Isotropic Liquid Crystal Elastomers as Exceptional Photoelastic Strain Sensors

A family of acrylate-based isotropic Liquid Crystal Elastomers (LCEs) exhibit stress- and strain-optic coefficients orders of magnitude greater than conventional polymeric and photoelastic materials. The three materials, composed of liquid crystalline and nonliquid crystalline monomers, show no nematic phase at any temperature. One of the materials has previously been synthesized with nematic symmetry, but here is instead templated with isotropic symmetry, demonstrating a previously unrealized idea proposed by de Gennes in 1969. Uniaxial strains applied to each material induce nematic ordering which we quantify using dye-absorption spectra and polarized Raman Spectroscopy. We deduce the coupling constants between the nematic liquid crystal order parameter and applied strain varies between 0.37 ± 0.02 and 0.66 ± 0.02—values large compared to other LCE systems. The combination of high strain-optic coefficients (0.048 ± 0.003 to 0.11 ± 0.01) and high compliances (245 ± 18 to 1900 ± 100 GPa–1) demonstrates that isotropic LCEs are exciting candidates for photoelastic coatings for assessing deformations across soft devices and biomaterials