48,187 research outputs found
Quasiparticle cooling of a single-Cooper-pair-transistor
A superconducting tunnel junction is used to directly extract quasiparticles
from one of the leads of a single-Cooper-pair-transistor. The consequent
reduction in quasiparticle density causes a lower rate of quasiparticle
tunneling onto the device. This rate is directly measured by radio-frequency
reflectometry. Local cooling may be of direct benefit in reducing the effect of
quasiparticles on coherent superconducting nanostructures.Comment: 4 figure
Low energy activation analysis for geochemical exploration
Low energy activation analysis for geochemical exploratio
Characterization of low intensity X-ray imaging devices (Lixiscope)
Radioisotopic sources were used to excite the LIXISCOPE in preliminary experimental attempts to evaluate the usefulness of this instrument for industrial and medical applications. The characteristics of the LIXISCOPE when excited by x-ray produced by conventional electrically powered x-ray generators were studied. The optimum x-ray spectrum was determined and the mode of operation of the generator, which yields satisfactory LIXISCOPE images of medical and industrial specimens was investigated
Evaluation of the advance/anticipatory care planning (ACP) facilitators training programme
This report presents an overview of the findings of the three phases of the study and assesses the degree to which the Facilitator Training Programme and Resource Pack have prepared the cohort of facilitators with the knowledge, skills and tools to deliver training initiatives in ACP to address local and regional needs
Effects of starvation on energy density of juvenile chum salmon (Oncorhynchus keta) captured in marine waters of Southeastern Alaska
We conducted laboratory starvation experiments on juvenile
chum salmon (Oncorhynchus keta) captured in the neritic marine waters of northern Southeast Alaska in June and July 2003. Temporal changes in fish energy density (whole body energy content [WBEC], cal/g dry weight), percent moisture content, wet weight (g), length (mm), and size-related condition residuals were measured in the laboratory and were then compared to long-term field data. Laboratory
water temperatures and salinities averaged 9°C and 32 psu in both months. Trends in response variables were similar for both experimental groups, although sampling intervals
were limited in July because fewer fish were available (n= 54) than in June (n=101). Overall, for June (45-d experimental period, 9 intervals), WBEC, wet weight, and condition residuals decreased and percent moisture content increased, whereas fork length did not change. For July
(20-d experimental period, 5 intervals), WBEC and condition residuals decreased, percent moisture content and fork length increased, and wet weight did not change. WBEC, percent moisture content, and condition residuals fell outside the norm of longterm data ranges within 10–15 days
of starvation, and may be more useful than fork length and wet weight for detecting fish condition responses to
suboptimal environments
Nanoindentation of bone: Comparison of specimens tested in liquid and embedded in polymethylmethacrylate
Elastic modulus of bone was investigated by nanoindentation using common methods of sample preparation, data collection, and analysis, and compared to dynamic mechanical analysis (DMA: three-point bending) for the same samples. Nanoindentation (Berkovich, 5 μm and 21 μm radii spherical indenters) and DMA were performed on eight wet and dehydrated (100% ethanol), machined equine cortical bone beams. Samples were embedded in polymethylmethacrylate (PMMA) and mechanical tests repeated. Indentation direction was transverse to the bone long axis while DMA tested longitudinally, giving approximately 12% greater modulus in DMA. For wet samples, nanoindentation with spherical indenters revealed a low modulus surface layer. Estimates of the volume of material contributing to elastic modulus measurement showed that the surface layer influences the measured modulus at low loads. Consistent results were obtained for embedded tissue regardless of indenter geometry, provided appropriate methods and analysis were used. Modulus increased for nanoindentation (21 μm radius indenter) from 11.7 GPa ± 1.7 to 15.0 GPa ± 2.2 to 19.4 GPa ± 2.1, for wet, dehydrated in ethanol, and embedded conditions, respectively. The large increases in elastic modulus caused by replacing water with ethanol and ethanol with PMMA demonstrate that the role of water in fine pore space and its interaction with collagen strongly influence the mechanical behavior of the tissue
Development of hazard analysis and critical control points (HACCP) procedures to control organic chemical hazards in the agricultural production of raw food commodities
Hazard Analysis by Critical Control Points (HACCP) is a systematic approach to the identification, assessment and control of hazards in the food chain. Effective HACCP requires the consideration of all possible hazards, i.e., chemical, microbiological and physical. However, current procedures focus primarily upon microbiological and physical hazards, and, to date, chemical aspects of HACCP have received relatively little attention. Consequently, this report discusses the application of HACCP to organic chemical contaminants and the particular problems that are likely to encounter within the agricultural sector. It also presents generic templates for the development of organic chemical contaminant HACCP procedures for selected raw food commodities, i.e., cereal crops, raw meats and milk
- …