Particle Motion and Scalar Field Propagation in Myers-Perry Black Hole Spacetimes in All Dimensions

We study separability of the Hamilton-Jacobi and massive Klein-Gordon equations in the general Myers-Perry black hole background in all dimensions. Complete separation of both equations is carried out in cases when there are two sets of equal black hole rotation parameters, which significantly enlarges the rotational symmetry group. We explicitly construct a nontrivial irreducible Killing tensor associated with the enlarged symmetry group which permits separation. We also derive first-order equations of motion for particles in these backgrounds and examine some of their properties.Comment: 16 pages, LaTeX2

Mixed Alcohol Synthesis Catalyst Screening

National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs

Structure of the Hemagglutinin Precursor Cleavage Site, a Determinant of Influenza Pathogenicity and the Origin of the Labile Conformation

AbstractThe membrane fusion potential of influenza HA, like many viral membrane-fusion glycoproteins, is generated by proteolytic cleavage of a biosynthetic precursor. The three-dimensional structure of ectodomain of the precursor HA0 has been determined and compared with that of cleaved HA. The cleavage site is a prominent surface loop adjacent to a novel cavity; cleavage results in structural rearrangements in which the nonpolar amino acids near the new amino terminus bury ionizable residues in the cavity that are implicated in the low-pH-induced conformational change. Amino acid insertions at the cleavage site in HAs of virulent avian viruses and those of viruses isolated from the recent severe outbreak of influenza in humans in Hong Kong would extend this surface loop, facilitating intracellular cleavage

InGaP/GaAsHBTsにおける表面欠陥の及ぼす信頼性の問題

電気通信大学200

Analysis of the Effects of Compositional and Configurational Assumptions on Product Costs for the Thermochemical Conversion of Lignocellulosic Biomass to Mixed Alcohols -- FY 2007 Progress Report

The purpose of this study was to examine alternative biomass-to-ethanol conversion process assumptions and configuration options to determine their relative effects on overall process economics. A process-flow-sheet computer model was used to determine the heat and material balance for each configuration that was studied. The heat and material balance was then fed to a costing spreadsheet to determine the impact on the ethanol selling price. By examining a number of operational and configuration alternatives and comparing the results to the base flow sheet, alternatives having the greatest impact the performance and cost of the overall system were identified and used to make decisions on research priorities

Evaluation of Promoters for Rhodium-Based Catalysts for Mixed Alcohol Synthesis

Pacific Northwest National Laboratory (PNNL) and National Renewable Energy Laboratory (NREL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially-available catalysts or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially-available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. A total of 28 tests were conducted to evaluate 22 different promoters as well as an unpromoted catalyst. The following general trends were observed for the test results: • The highest carbon selectivity to C2+ oxygenates occurred at the lowest reaction temperatures and accompanying lowest space time yields (STYs). • The lowest carbon selectivity to C2+ oxygenates occurred at the highest reaction temperatures because of high carbon conversion to hydrocarbons. • The highest C2+-oxygenate STYs occurred between 300°C and 325°C, with the gas hourly space velocity (GHSV) adjusted when necessary to maintain carbon conversion ranges between ~ 30 and 40 percent. Higher carbon selectivity to hydrocarbons at higher temperatures resulted in lower C2+-oxygenate STYs. • When catalysts were heated to between 300°C and 325°C the catalysts showed evidence of some deactivation with respect to C2+ oxygenate productivity, accompanied by reduced chain growth for the hydrocarbon products. The degree of deactivation and the temperature at which it occurred varied between the different catalysts tested. Of all of the catalysts evaluated, the Li-promoted catalysts had the highest carbon selectivity to C2+ oxygenates (47 percent) under the conditions at which the maximum C2+-oxygenate STYs were obtained

Mixed Alcohol Synthesis Catalyst Screening 2007 Progress Report

Pacific Northwest National Laboratory (PNNL) and National Renewable Energy Laboratory (NREL) are researching the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is obtaining commercially available mixed alcohol or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. The most promising catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. After a review of the literature in 2006 and conversations with companies that produce catalysts, it was determined that no commercial mixed-alcohol synthesis catalysts were available. One manufacturer supplied a modified methanol catalyst that was tested in the PNNL laboratory-scale system and provided to NREL for further testing. PNNL also prepared and tested the behavior of 10 other catalysts representing the distinct catalyst classes for mixed alcohol syntheses. Based on those results,testing in 2007 focused on the performance of the rhodium-based catalysts. The effects of adding promoters to the rhodium catalysts in addition to the manganese already being used were examined. The iron and rhenium promoters both stood out as achieving higher carbon selectivities , followed by Cu. Iridium and Li, on the other hand, had low carbon selectivity ratios of 0.27 and 0.22, respectively. Although testing of candidate promoters is not complete, it appears that Ir and Li promoters warrant further optimization and possibly combination to further improve STYs and carbon selectivities to C2+ oxygenates. However, using these promoters, it will be necessary to incorporate a separate hydrogenation catalyst to improve the yield of C2+ alcohols with respect to the other oxygenates. Fe, Re, and Cu stand out as possible candidates in this respect, but additional research is needed to examine whether they can be combined with the other promoters on the Rh-based catalyst or need to be optimized on a separate catalyst support that is either physically mixed or used in series with the promoted Rh-based catalyst

Optimization of Rhodium-Based Catalysts for Mixed Alcohol Synthesis -- 2009 Progress Report

Pacific Northwest National Laboratory (PNNL) has been conducting research for the United States Department of Energy, Energy Efficiency Renewable Energy, Biomass Program to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). This research has involved the screening of potential catalysts, and optimization of the more promising ones, using laboratory scale reactors. During 2009, the main goal of the testing program focused on optimizing selected supported catalysts containing rhodium (Rh) and manganese (Mn). Optimization involved examining different total concentrations and atomic ratios of Rh and Mn as well as that of the more promising promoters (Ir and Li) identified in the earlier screening studies. Evaluation of catalyst performance focused on attaining improvements with respect to the space-time-yield and converted carbon selectivity to C2+ oxygenates, with additional consideration given to the fraction of the oxygenates that were C2+ alcohols

Ecology of Feral Pigeons: Population Monitoring, Resource Selection, and Management Practices

Feral pigeons (Columba livia) are typically ignored by ornithologists but can be found roosting in the thousands within cities across the world. Pigeons have been known to spread zoonoses, through ectoparasites and excrement they produce. Along with disease, feral pigeons have an economic impact due to the cost of cleanup and maintenance of human infrastructure. Many organizations have tried to decrease pigeon abundances through euthanasia or use of chemicals that decrease reproductive output. However, killing pigeons has been unsuccessful in decreasing abundance, and chemical inhibition can be expensive and must be used throughout the year. A case study at Texas Tech University has found that populations fluctuate throughout the year, making it difficult to manage numbers. To successfully decrease populations, it is important to have a multifaceted approach that includes removing necessary resources (i. e. nest sites and roosting areas) and decreasing the number of offspring through humane techniques

The use of different 16S rRNA gene variable regions in biogeographical studies

DATA AVAILABILITY STATEMENT : All Illumina sequences generated and analyzed in this study were deposited into the European Nucleotide Archive (accession number PRJEB55051).SUPPORTING INFORMATION 1 : FIGURE S1. Samples located in four inland areas of the Prince Charles Mountains (ME1 from Mount Rubin, ME2 and ME3 from Mawson Escarpment, MM1 and MM2 from Mount Menzies, LT1 and LT2 from Lake Terrasovoje), in the Reinbolt Hills (RH1), and in coastal sites in proximity of the Prince Charles Mountains (C1 and C2; see Table S1). Map was produced using MODIS mosaic (125 m) imagery distributed by Quantarctica (https://cmr.earthdata.nasa.gov/; https://www.npolar.no/quantarctica/). FIGURE S2. Pearson's pairwise correlations between Bray–Curtis dissimilarity matrices calculated on relative abundance taxonomic dataset (genus level; A), and between Jaccard dissimilarity matrices calculated on presence/absence taxonomic dataset (genus level; B). Correlations were calculated for all the variable region datasets (V1–V3, V3–V4, V4, V4–V5 and V8–V9), and the mixed datasets (Mix 1, Mix 2 and Mix 3) constituted by randomly picked samples from V1–V3, V3–V4, V4, V4–V5 and V8–V9 (Table S4). Pearson's correlation coefficients (r) are reported only in case of significant correlation (p < 0.05).SUPPORTING INFORMATION 2 : TABLE S1. Sample specifics. TABLE S2. Geochemical data. TABLE S3. Relative abundance (%) of the taxonomic domains Bacteria and Archaea in sample (i.e., ME1, ME2, ME3, MM1, MM2, LT1, LT2, RH1, C1 and C2) for each variable region dataset (i.e., V1–V3, V3–V4, V4, V4–V5 and V8–V9). TABLE S4. Composition of mixed communities. TABLE S5. Number of reads at each step of the 16S rRNA gene processing pipeline. *counts reported as read pairs. TABLE S6. Number and percentage of unknown amplicon sequence variants (ASVs) at genus level for each phylum. TABLE S7. Relative abundance associated to unknown amplicon sequence variants at genus-level for each phylum. TABLE S8. Pearson's correlations from pairwise comparisons of variable region datasets performed on number of genera (A), dominant genera (i.e., genera represented by a relative abundance higher than 1% in at least one sample) (B), rare genera (i.e., genera represented by a relative abundance lower than 0.1% in all samples (C), Shannon index (D) and unique genera (E).16S rRNA gene amplicon sequencing is routinely used in environmental surveys to identify microbial diversity and composition of the samples of interest. The dominant sequencing technology of the past decade (Illumina) is based on the sequencing of 16S rRNA hypervariable regions. Online sequence data repositories, which represent an invaluable resource for investigating microbial distributional patterns across spatial, environmental or temporal scales, contain amplicon datasets from diverse 16S rRNA gene variable regions. However, the utility of these sequence datasets is potentially reduced by the use of different 16S rRNA gene amplified regions. By comparing 10 Antarctic soil samples sequenced for five different 16S rRNA amplicons, we explore whether sequence data derived from diverse 16S rRNA variable regions can be validly used as a resource for biogeographical studies. Patterns of shared and unique taxa differed among samples as a result of variable taxonomic resolutions of the assessed 16S rRNA variable regions. However, our analyses also suggest that the use of multi-primer datasets for biogeographical studies of the domain Bacteria is a valid approach to explore bacterial biogeographical patterns due to the preservation of bacterial taxonomic and diversity patterns across different variable region datasets. We deem composite datasets useful for biogeographical studies.Australian Antarctic Division, Australian Research Council and NRF SANAP.http://wileyonlinelibrary.com/journal/emi4hj2023BiochemistryGeneticsMicrobiology and Plant Patholog