Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing

The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes

Development and testing of impregnated La0.20Sr0.25Ca0.45TiO3 anode microstructures for solid oxide fuel cells

Funding: EPSRC project EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes”, the University of St Andrews and HEXIS AG.The A-site deficient perovskite: La0.20Sr0.25Ca0.45TiO3 (LSCTA-) is a mixed ionic and electronic conductor (MIEC) which shows promising performance as a Solid Oxide Fuel Cell (SOFC) anode ‘backbone’ material, when impregnated with metallic and oxide-ion conducting electrocatalysts. Here, we present data on the complete ceramic processing and optimisation of the LSCTA- ‘backbone’ microstructure, in order to improve current distribution throughout the anode. Through control of ink rheology, screen printing parameters and sintering protocol an advantageous LSCTA- microstructural architecture was developed, exhibiting an ‘effective’ conductivity of 21 S cm-1. Incorporation of this LSCTA- anode microstructure into SOFC and impregnation with Ce0.80Gd0.20O1.9 and either Ni, Ru, Rh, Pt or Pd resulted in promising initial performances during fuel cell testing in a fuel stream of 97% H2:3% H2O. Area Specific Resistances of 0.41 Ω cm2 and 0.39 Ω cm2 were achieved with anodes containing Rh/CGO and Pd/CGO, respectively.Postprin

Development and testing of impregnated La0.20Sr0.25Ca0.45TiO3 anode microstructures for solid oxide fuel cells

Funding: EPSRC project EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes”, the University of St Andrews and HEXIS AG.The A-site deficient perovskite: La0.20Sr0.25Ca0.45TiO3 (LSCTA-) is a mixed ionic and electronic conductor (MIEC) which shows promising performance as a Solid Oxide Fuel Cell (SOFC) anode ‘backbone’ material, when impregnated with metallic and oxide-ion conducting electrocatalysts. Here, we present data on the complete ceramic processing and optimisation of the LSCTA- ‘backbone’ microstructure, in order to improve current distribution throughout the anode. Through control of ink rheology, screen printing parameters and sintering protocol an advantageous LSCTA- microstructural architecture was developed, exhibiting an ‘effective’ conductivity of 21 S cm-1. Incorporation of this LSCTA- anode microstructure into SOFC and impregnation with Ce0.80Gd0.20O1.9 and either Ni, Ru, Rh, Pt or Pd resulted in promising initial performances during fuel cell testing in a fuel stream of 97% H2:3% H2O. Area Specific Resistances of 0.41 Ω cm2 and 0.39 Ω cm2 were achieved with anodes containing Rh/CGO and Pd/CGO, respectively.Postprin

An Azide-Functionalized Nitronyl Nitroxide Radical: Synthesis, Characterization and Staudinger-Bertozzi Ligation Reactivity

An azide-functionalized nitronyl nitroxide was successfully synthesized and its reactivity towards the Staudinger-Bertozzi ligation was explored. While a model reaction in solution showed the conversion of the nitronyl nitroxide to an imino nitroxide radical, the same reaction at the interface of gold nanoparticles allowed for successful covalent incorporation of the nitronyl nitroxide radical onto the nanoparticles

Integrating Aircraft Cost Modeling into Conceptual Design

The article presents cost modeling results from the application of the Genetic-Causal cost modeling principle. Industrial results from redesign are also presented to verify the opportunity for early concept cost optimization by using Genetic-Causal cost drivers to guide the conceptual design process for structural assemblies. The acquisition cost is considered through the modeling of the recurring unit cost and non-recurring design cost. The operational cost is modeled relative to acquisition cost and fuel burn for predominately metal or composites designs. The main contribution of this study is the application of the Genetic-Causal principle to the modeling of cost, helping to understand how conceptual design parameters impact on cost, and linking that to customer requirements and life cycle cost

The CBLAST-Hurricane program and the next-generation fully coupled atmosphere–wave–ocean models for hurricane research and prediction

Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 88 (2007): 311-317, doi:10.1175/bams-88-3-311.The record-setting 2005 hurricane season has highlighted the urgent need for a better understanding of the factors that contribute to hurricane intensity, and for the development of corresponding advanced hurricane prediction models to improve intensity forecasts. The lack of skill in present forecasts of hurricane intensity may be attributed, in part, to deficiencies in the current prediction models—insufficient grid resolution, inadequate surface and boundary-layer formulations, and the lack of full coupling to a dynamic ocean. The extreme high winds, intense rainfall, large ocean waves, and copious sea spray in hurricanes push the surface-exchange parameters for temperature, water vapor, and momentum into untested regimes. The Coupled Boundary Layer Air–Sea Transfer (CBLAST)-Hurricane program is aimed at developing improved parameterizations using observations from the CBLAST-Hurricane field program that will be suitable for the next generation of hurricane-prediction models. The most innovative aspect of the CBLAST-Hurricane modeling effort is the development and testing of a fully coupled atmosphere–wave–ocean modeling system that is capable of resolving the eye and eyewall at ~1-km grid resolution, which is consistent with a key recommendation for the next-generation hurricane-prediction models by the NOAA Science Advisor Board Hurricane Intensity Research Working Group. It is also the National Centers for Environmental Prediction (NCEP) plan for the new Hurricane Weather Research and Forecasting (HWRF) model to be implemented operationally in 2007–08.The CBLAST-Hurricane is a research program supported by a departmental research initiative at the Office of Naval Research (ONR). The research is supported by ONR Research Grants N00014-01-1-0156, N00014-04-1-0109, N00014-01-F-0052, and SBIR for the EM-APEX development and deployment

Durability of La0.20Sr0.25Ca0.45TiO3-based SOFC anodes : identifying sources of degradation in Ni and Pt/ceria co-impregnated fuel electrode microstructures

Funding from the University of St Andrews and HEXIS AG is acknowledged, in addition to the EPSRC Grants: EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes” and EP/L017008/1 “Capital for Great Technologies”.Solid oxide fuel cells (SOFC) comprising LSM-YSZ/LSM composite cathodes, 6ScSZ electrolytes and La0.20Sr0.25Ca0.45TiO3 (LSCTA−) anode ‘backbone’ microstructures were prepared using thick-film ceramic processing techniques. Activation and decoration of the LSCTA− anode ‘backbone’ with electrocatalytic coatings of cerium-based oxides and metallic Ni or Pt particles was achieved using the technique of catalyst co-impregnation. SOFC containing Ni/CGO, Ni/CeO2 and Pt/CGO impregnated LSCTA anodes were tested up to ∼1000 hours by the Swiss SOFC manufacturer: HEXIS, under realistic operating conditions, including 15 redox, thermo and thermoredox cycles. The voltage degradation rates observed over the entire test period for the SOFC containing the Ni/CGO, Ni/CeO2 and Pt/CGO impregnated LSCTA− anodes were 14.9%, 7.7% and 13.4%, respectively. Post-mortem microscopic analyses indicated that CeO2 formed ubiquitous coatings upon the LSCTA− anode microstructure, allowing retention of a high population density of metallic (Ni) particles, whilst CGO formed ‘islands’ upon the microstructure and some agglomerates within the pores, leading to more facile agglomeration of metallic (Ni and Pt) nanoparticles. Correlation of the post-mortem microscopy with AC impedance analysis revealed that the agglomeration of metallic catalyst resulted in an increase in the high-frequency anode polarisation resistance, whilst agglomeration of the ceria-based component directly resulted in the development of a low-frequency process that may be attributed to combined contributions from gas conversion and chemical capacitance.PostprintPostprintPeer reviewe

Tracing melioidosis back to the source: using whole-genome sequencing to investigate an outbreak originating from a contaminated domestic water supply

Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillus Burkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic. B. pseudomallei is classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure. B. pseudomallei isolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir of B. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens