34 research outputs found

    Behaviour and effects of fluorine in annealed n+ polycrystalline silicon layers on silicon wafers

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    A comprehensive study is made of the behaviour and effects of fluorine in n+ polysilicon layers. Sheet resistance, TEM and SIMS are used to obtain quantitative data for the breakup of the interfacial oxide, the epitaxial regrowth of the polysilicon and the fluorine and arsenic distributions. The fluorine significantly increases both the initial oxide breakup and the initial polysilicon regrowth. It also produces inclusions in the layer which can affect the subsequent polysilicon regrowth and the arsenic distributions. Three regrowth stages and two regrowth mechanisms are distinguished and interpreted and a value of approximately 6x1011cm2s-1 is deduced for the effective diffusivity of fluorine in polysilicon at 950°C

    Timber Talk, Vol. 47, No. 3, September 1, 2009

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    Lumber Market News ; Hardwood Lumber Price Trends—Green; Hardwood Lumber Price Trends—Kiln Dried; Softwood Lumber Price Trends; Timber Stumpage Prices; Logger Safety Training Sept. 5; Nebraska Timber Industry; Nebraska Wood Waste; Nebraska Forestry Industry Spotlight; Timberland Investment Outputs; The Trading Post

    Revenu, caractéristiques sociodémographiques et dépenses des ménages au Canada en 1978 et 1982

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    Ce texte examine, à l’aide de micro-données sur les dépenses des ménages canadiens en 1978 et 1982, comment leur revenu, leur taille et composition, leur participation au marché du travail, leur lieu de résidence et divers autres caractéristiques socio-démographiques (âge, scolarité, langue, …) expliquent leurs dépenses pour quatorze agrégats (aliments à la maison, logement, vêtements, …). Les résultats indiquent que des facteurs économiques tels le cycle de vie et la rareté du temps permettent d’expliquer ces dépenses.This paper examines, using micro-data on the expenditures of Canadian households for 1978 and 1982, how their income, their size and make-up, their labour force participation, their place of residence and other sociodemographic characteristics (age, schooling, language, …) explain their expenditures on fourteen aggregates (food at home, housing, clothing …). The results show that economic factors such as the life cycle and the scarcity of time allow us to explain these expenditures

    Classification of La3+ and Gd3+ rare earth ions using surface-enhanced Raman scattering

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    In this study, surface-enhanced Raman scattering (SERS) spectra of different rare earth (RE) ion-citrate complexes were investigated for the first time for the qualitative classification of RE3+ ions. With the addition of RE3+ ions to citrate-capped silver nanoparticles in aqueous solutions, the Raman signals of RE-citrate complexes were enhanced, and characteristic peaks appeared near 1065 cm-1 and 1315 cm-1. The I1065/I1315 ratios of La-citrate and Gd-citrate were approximately 1 and 0.5, respectively. Thus, different RE3+ ions were classified based on the ratio of characteristic SERS peaks near 1065 cm-1 and 1315 cm-1. In addition, the effects of RE3+ ions in the RE-citrate complexes were analyzed based on density functional theory (DFT) calculations. Calculation results show that these characteristic peaks are attributed to the coordination of carboxyl and hydroxyl groups of citrates with the RE3+ ions, suggesting that these are spin-related bands of the RE-citrate complexes

    Public Opinions of Unmanned Aerial Technologies in 2014 to 2019: A Technical and Descriptive Report

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    The primary purpose of this report is to provide a descriptive and technical summary of the results from similar surveys administered in fall 2014 (n = 576), 2015 (n = 301), 2016 (ns = 1946 and 2089), and 2018 (n = 1050) and summer 2019 (n = 1300). In order to explore a variety of factors that may impact public perceptions of unmanned aerial technologies (UATs), we conducted survey experiments over time. These experiments randomly varied the terminology (drone, aerial robot, unmanned aerial vehicle (UAV), unmanned aerial system (UAS)) used to describe the technology, the purposes of the technology (for economic, environmental, or security goals), the actors (public or private) using the technology, the technology’s autonomy (fully autonomous, partially autonomous, no autonomy), and the framing (promotion or prevention) used to describe the technology’s purpose. Initially, samples were recruited through Amazon’s Mechanical Turk, required to be Americans, and paid a small amount for participation. In 2016 we also examined a nationally representative samples recruited from Qualtrics panels. After 2016 we only used nationally representative samples from Qualtrics. Major findings are reported along with details regarding the research methods and analyses

    Characterization of small RNA populations in non-transgenic andaflatoxin-reducing-transformed peanut

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    Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumula-tion of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNApopulations in a control line and in two transformed peanut lines that expressed an inverted repeattargeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was to determine the putative involvement of the smallRNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins
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