Lead-oxygen closed-loop battery system

Calculations show that battery can deliver up to 35 watt-hours per pound, conventional lead-acid batteries deliver 10 to 15 watt-hours per pound. Weight reduction is due to replacement of solid lead-peroxide electrodes with metal current-collector screen, catalyst, and Teflon membrane

Semiconductor process chamber coatings: Improving performance and uptime

Corrosion resistance is a critical property for semiconductor processing chamber components. Corrosive plasmas are omnipresent is semiconductor deposition processes, including plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), and etching. Process chamber cleanliness during plasma processing is becoming increasingly important as device feature sizes shrink. Particles that originate from erosion of the chamber components can lead to device yield losses, and eventually will result in the process chamber requiring the replacement of chamber components that are exposed to such plasmas. Thus the chamber components coatings are critical for tool performance and uptime. Please click Additional Files below to see the full abstract

Crystal field states of Kondo lattice heavy fermions CeRuSn3 and CeRhSn3

Inelastic neutron scattering experiments have been carried out to determine the crystal field states of the Kondo lattice heavy fermions CeRuSn3 and CeRhSn3. Both the compounds crystallize in LaRuSn3-type cubic structure (space group Pm-3n) in which the Ce atoms occupy two distinct crystallographic sites with cubic (m-3) and tetragonal (-4m.2) point symmetries. The INS data of CeRuSn3 reveal the presence of a broad excitation centered around 6-8 meV which is accounted by a model based on crystal electric field (CEF) excitations. On the other hand, the INS data of isostructural CeRhSn3 reveal three CEF excitations around 7.0, 12.2 and 37.2 meV. The neutron intensity sum rule indicates that the Ce ions at both cubic and tetragonal Ce sites are in Ce3+ state in both CeRuSn3 and CeRhSn3. The CEF level schemes for both the compounds are deduced. We estimate the Kondo temperature T_K = 3.1(2) K for CeRuSn3 from neutron quasielastic linewidth in excellent agreement with that determined from the scaling of magnetoresistance which gives T_K = 3.2(1) K. For CeRhSn3 the neutron quasielastic linewidth gives T_K = 4.6 K. For both CeRuSn3 and CeRhSn3, the ground state of Ce3+ turns out to be a quartet for the cubic site and a doublet for the tetragonal site.Comment: 12 pages, 13 figures, 2 tables, to appear in Phys. Rev.

Physical properties of noncentrosymmetric superconductor LaIrSi3: A {\mu}SR study

The results of heat capacity C_p(T, H) and electrical resistivity \rho(T,H) measurements down to 0.35 K as well as muon spin relaxation and rotation (\muSR) measurements on a noncentrosymmetric superconductor LaIrSi3 are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal BaNiSn3-type structure (space group I4\,mm) of LaIrSi3. The bulk superconductivity is observed below T_c = 0.72(1) K. The intrinsic \Delta C_e/\gamma_n T_c = 1.09(3) is significantly smaller than the BCS value of 1.43, and this reduction is accounted by the \alpha-model of BCS superconductivity. The analysis of the superconducting state C_e(T) data by the single-band \alpha-model indicates a moderately anisotropic order parameter with the s-wave gap \Delta(0)/k_B T_c = 1.54(2) which is lower than the BCS value of 1.764. Our estimates of various normal and superconducting state parameters indicate a weakly coupled electron-phonon driven type-I s-wave superconductivity in LaIrSi3. The \muSR results also confirm the conventional type-I superconductivity in LaIrSi3 with a preserved time reversal symmetry and hence a singlet pairing superconducting ground state.Comment: 11 pages, 8 figures, 2 table

The life history responses of the abalone pest, Terebrasabella heterouncinata, under natural and aquaculture conditions

The sabellid, Terebrasabella heterouncinata, is a small (<5 mm) intratubular brooder that lives in burrows within the host s shell matrix. It is a semi-continuous breeder and despite producing small numbers of large eggs, infestation by this animal has reached epidemic proportions on local abalone farms. The present study compared the morphometrics and reproductive characteristics of worms from farmed and wild abalone, in the Walker Bay area of the south Western Cape Province of South Africa, to gain insights into why this animal has become so successful under aquaculture conditions. The farms designated farm A and farm B each had one on-farm site, and two wild sites, while farm C had two on-farm sites and two wild sites. The wild sites were natural abalone habitats located within 2.5 km of the farms. Our results conclusively showed that environmental conditions prevalent on the farms enhanced the reproductive success of these worms relative to that observed in its natural environment. At farms B and C, worms occurred in significantly higher densities at the on-farm sites than in the corresponding wild samples, but at farm A, density was equally low at the three sites. At all three farms, a greater proportion of the population was reproductively active in the on-farm samples than in the wild samples. Worms on farmed abalone had a higher instantaneous fecundity, brooded more clutches simultaneously and were larger than their conspecifics from the wild. There was a positive correlation between adult size and brood size and the number of clutches brooded simultaneously. Within the three on-farm sites there was a negative correlation between egg volume and brood size, indicating a trade-off between these traits. However, such a trade-off was not apparent between sites, with brood size being higher at the on-farm sites than at the wild sites, irrespective of egg size. This suggests that the stable nutrient-enriched environment on the farm led to an increase in fecundity without compromising the size (and implicitly the quality) of the eggs. Worm density did not have a significant effect on body size or any other reproductive traits at most sites, and the density of T. heterouncinata was unaffected by the density of other shell-infesting polychaetes. The results suggest that the farm environment has selected for larger, more fecund worms that breed rapidly with high recruitment success as a consequence of abundant nutrients, high host density, habitat stability and a possible lack of predation and interspecific competition

Molecular detection of carbapenemase-producing genes in referral Enterobacteriaceae in South Africa: A short report

Molecular confirmation of carbapenemase-producing Enterobacteriaceae (CPE) was introduced in South Africa (SA) at the end of 2011. We report on the detection of these resistance genes based on referral isolates. Enterobacteriaceae with non-susceptibility to any of the carbapenems according to defined criteria for antimicrobial susceptibility testing results were sent to a reference laboratory. A proportion of isolates had limited demographic, epidemiological and clinical data available. Organism identification was reconfirmed using reference laboratory methods, and the presence of carbapenemases was confirmed with a real-time polymerase chain reaction. We analysed 1 503 significant isolates received for confirmation from the National Health Laboratory Service and some private laboratories during 2012 - 2015 and confirmed one or more carbapenemase-producing genes in 68% of isolates, the most common organism being Klebsiella pneumoniae (60%). The most common carbapenemase genes were blaNDM, followed by blaOXA-48 and its variants. BlaOXA-48 and its variants demonstrated non-susceptibility to ertapenem in 89% of the isolates when analysed by the phenotypic method, and to ceftazidime in 34%. Overall, the detection rate for carbapenemases in K. pneumoniae blood isolates in the public sector was 1.9% during the 4-year period. This report indicates the presence of CPE in SA, and it is important for all healthcare workers to be aware of this major public health threat so that infection prevention and control measures can be implemented to prevent the spread of CPE in healthcare facilities

Group divisible designs with block size 4 and group sizes 4 and 7

In this paper, we consider the existence of group divisible designs (GDDs) with block size $4$ and group sizes $4$ and $7$. We show that there exists a 4-GDD of type $4^t 7^s$ for all but a finite specified set of feasible values for $(t, s)$.Comment: arXiv admin note: substantial text overlap with arXiv:2109.1122

Linking an economic model for European agriculture with a mechanistic model to estimate nitrogen losses from cropland soil in Europe

International audienceFor the comprehensive assessment of the policy impact on greenhouse gas emissions from agricultural soils both socio-economic aspects and the environmental heterogeneity of the landscape are important factors that must be considered. We developed a modelling framework that links the large-scale economic model for agriculture CAPRI with the bio-geochemistry model DNDC to simulate greenhouse gas fluxes, carbon stock changes and the nitrogen budget of agricultural soils in Europe. The framework allows the ex-ante simulation of agricultural or agri-environmental policy impacts on wide range of environmental problems such as climate change (greenhouse gas emissions), air pollution and groundwater pollution. Those environmental impacts can be analysed in the context of economic and social indicators as calculated by the economic model. The methodology consists in four steps (i) the definition of appropriate calculation units that can be considered as homogeneous in terms of economic behaviour and environmental response; (ii) downscaling of regional agricultural statistics and farm management information from a CAPRI simulation run into the spatial calculation units; (iii) setting up of environmental model scenarios and model runs; and finally (iv) aggregating results for interpretation. We show first results of the nitrogen budget in cropland for the area of fourteen countries of the European Union. These results, in terms of estimated nitrogen fluxes, must still be considered as illustrative as needs for improvements in input data (e.g. the soil map) and management data (yield estimates) have been identified and will be the focus of future work. Nevertheless, we highlight inter-dependencies between farmer's choices of land uses and the environmental impact of different cultivation systems