163,955 research outputs found
Current economic and sensitivity analysis for ID slicing of 4 inch and 6 inch diameter silicon ingots for photovoltaic applications
The economics and sensitivities of slicing large diameter silicon ingots for photovoltaic applications were examined. Current economics and slicing add on cost sensitivities are calculated using variable parameters for blade life, slicing yield, and slice cutting speed. It is indicated that cutting speed has the biggest impact on slicing add on cost, followed by slicing yield, and by blade life as the blade life increases
Domino Waves
Motivated by a proposal of Daykin (Problem 71-19*, SIAM Review 13 (1971)
569), we study the wave that propagates along an infinite chain of dominoes and
find the limiting speed of the wave in an extreme case.Comment: 10 pages, 5 figure
Coulomb-Modified Fano Resonance in a One-Lead Quantum Dot
We investigate a tunable Fano interferometer consisting of a quantum dot
coupled via tunneling to a one-dimensional channel. In addition to Fano
resonance, the channel shows strong Coulomb response to the dot, with a single
electron modulating channel conductance by factors of up to 100. Where these
effects coexist, lineshapes with up to four extrema are found. A model of
Coulomb-modified Fano resonance is developed and gives excellent agreement with
experiment.Comment: related papers available at http://marcuslab.harvard.ed
Management of invasive Allee species
In this study, we use a discrete, two-patch population model of an Allee species to examine different methods in managing invasions. We first analytically examine the model to show the presence of the strong Allee effect, and then we numerically explore the model to test the effectiveness of different management strategies. As expected invasion is facilitated by lower Allee thresholds, greater carrying capacities and greater proportions of dispersers. These effects are interacting, however, and moderated by population growth rate. Using the gypsy moth as an example species, we demonstrate that the effectiveness of different invasion management strategies is context-dependent, combining complementary methods may be preferable, and the preferred strategy may differ geographically. Specifically, we find methods for restricting movement to be more effective in areas of contiguous habitat and high Allee thresholds, where methods involving mating disruptions and raising Allee thresholds are more effective in areas of high habitat fragmentation
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Relationships between estimated autozygosity and complex traits in the UK Biobank
<div><p>Inbreeding increases the risk of certain Mendelian disorders in humans but may also reduce fitness through its effects on complex traits and diseases. Such inbreeding depression is thought to occur due to increased homozygosity at causal variants that are recessive with respect to fitness. Until recently it has been difficult to amass large enough sample sizes to investigate the effects of inbreeding depression on complex traits using genome-wide single nucleotide polymorphism (SNP) data in population-based samples. Further, it is difficult to infer causation in analyses that relate degree of inbreeding to complex traits because confounding variables (e.g., education) may influence both the likelihood for parents to outbreed and offspring trait values. The present study used runs of homozygosity in genome-wide SNP data in up to 400,000 individuals in the UK Biobank to estimate the proportion of the autosome that exists in autozygous tracts—stretches of the genome which are identical due to a shared common ancestor. After multiple testing corrections and controlling for possible sociodemographic confounders, we found significant relationships in the predicted direction between estimated autozygosity and three of the 26 traits we investigated: age at first sexual intercourse, fluid intelligence, and forced expiratory volume in 1 second. Our findings corroborate those of several published studies. These results may imply that these traits have been associated with Darwinian fitness over evolutionary time. However, some of the autozygosity-trait relationships were attenuated after controlling for background sociodemographic characteristics, suggesting that alternative explanations for these associations have not been eliminated. Care needs to be taken in the design and interpretation of ROH studies in order to glean reliable information about the genetic architecture and evolutionary history of complex traits.</p></div
High Efficiency Large Area Polysilicon Solar Cells
Large area (100 sq cm) polysilicon solar cells having efficiencies of up to 14.1% (100 mW/sq cm, 25 C) were fabricated and a detailed analysis was performed to identify the efficiency loss mechanisms. The 1-5 characteristics of the best cell were dominated by recombination in the quasi-neutral base due to the combination of minority carrier diffusion length and base resistivity. An analysis of the microstructural defects present in the material and their effect on the electrical properties is presented
Two systems developed for purifying inert atmospheres
Two systems, one for helium and one for argon, are used for purifying inert atmospheres. The helium system uses an activated charcoal bed at liquid nitrogen temperature to remove oxygen and nitrogen. The argon system uses heated titanium sponge to remove nitrogen and copper wool beds to remove oxygen. Both use molecular sieves to remove water vapor
Topological gravity localization on a delta-function like Brane
Besides the String Theory context, the quantum General Relativity can be
studied by the use of constrained topological field theories. In the celebrated
Plebanski formalism, the constraints connecting topological field theories and
gravity are imposed in space-times with trivial topology. In the braneworld
context there are two distinct regions of the space-time, namely, the bulk and
the braneworld volume. In this work we show how to construct topological
gravity in a scenario containing one extra dimension and a delta-function like
3-brane which naturally emerges from a spontaneously broken discrete symmetry.
Starting from a D=5 theory we obtain the action for General Relativity in the
Palatini form in the bulk as well as in the braneworld volume. This result is
important for future insights about quantum gravity in brane scenarios.Comment: 4 page
Four-dimensional worldwide atmospheric models: ANYPT and ANYRG
Computer programs read magnetic-tape data bases and computer meteorological profiles for any position, time, and height (from zero to 25 km). System assists in analyses of distortion of information obtained from aircraft-mounted or spacecraft-mounted electromagnetic sensors
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