646 research outputs found

    Growth of single-crystal gallium nitride

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    Use of ultrahigh purity ammonia prevents oxygen contamination of GaN during growth, making it possible to grow the GaN at temperatures as high as 825 degrees C, at which point single crystal wafers are deposited on /0001/-oriented sapphire surfaces

    P-n junctions formed in gallium antimonide

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    Vapor phase deposition process forms a heavily doped n-region on a melt-grown p-type gallium antimonide substrate. HCl transports gallium to the reaction zone, where it combines with antimony hydride and the dopant carrier, hydrogen telluride. Temperatures as low as 400 degrees C are required

    Controlled substrate cooling improves reproducibility of vapor deposited semiconductor composites

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    Improved substrate holder preferentially provides more uniform substrate cooling and increases the proportion of vapor flowing over the substrate during growth. Nitrogen gas is constricted in the substrate holder to cool the substrate

    Vapor Phase Growth Technique and System for Several III-V Compound Semiconductors Interim Scientific Report

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    Vapor phase crystal growth and preparation of gallium, indium, arsenic, phosphorous, and antimony alloy semiconductor material

    Vapor phase growth technique and system for several 3-5 compound semiconductors Quarterly technical report

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    Vapor phase growth technique and system for group 3A and 5A compound semiconductor

    Vapor-phase growth technique and system for several III-V compound semiconductors Interim scientific report

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    Vapor phase growth technique for III-V compound semiconductors containing aluminu

    Vapor phase growth technique and system for several III-V compound semiconductors Interim scientific report

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    Vapor phase growth method for single crystalline preparation of gallium nitride, gallium arsenide alloy, and gallium antimonide allo

    Migraine and vascular disease biomarkers: A population-based case-control study.

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    Background The underpinnings of the migraine-stroke association remain uncertain, but endothelial activation is a potential mechanism. We evaluated the association of migraine and vascular disease biomarkers in a community-based population. Methods Participants (300 women, 117 men) were recruited as a part of the Dutch CAMERA 1 (Cerebral Abnormalities in Migraine, an Epidemiologic Risk Analysis) study. Participants were aged 30-60 (mean 48) years, 155 migraine had with aura (MA), 128 migraine without aura (MO), and 134 were controls with no severe headaches. Plasma concentrations of fibrinogen, Factor II, D-dimer, high sensitivity C-reactive protein (hs-CRP), and von Willebrand factor antigen were compared between groups, also stratifying by sex. Results Fibrinogen and hs-CRP were elevated in migraineurs compared to controls. In logistic regression analyses, MO and MA had increased likelihood of elevated fibrinogen, and MA had increased likelihood of elevated Factor II and hs-CRP. Fibrinogen and Factor II were associated with MA in women but not men. In the migraine subgroup, the total number of years of aura, but not headache, predicted elevated hs-CRP, and the average number of aura, but not headache, attacks predicted all biomarkers but Factor II. Conclusions Elevated vascular biomarkers were associated with migraine, particularly MA, as well as with years of aura and number of aura attacks

    Benthic enrichment in the Georgia Bight related to Gulf Stream intrusions and estuarine outwelling

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    The distribution patterns of benthic biomass (microbiota, meiofauna, and macrofauna) over the expansive continental shelf of the Georgia Bight suggest nutrient inputs from intrusions of deep Gulf Stream waters at the shelf break…
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