9,097 research outputs found

    Single action separation mechanism Patent

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    Separation mechanism for use between stages of multistage rocket vehicle

    Electrical characterization Of SiGe thin films

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    An apparatus for measuring electrical resistivity and Hall coefficient on both thin films and bulk material over a temperature range of 300K to 1300K has been built. A unique alumina fixture, with four molybdenum probes, allows arbitrarily shaped samples, up to 2.5 cm diameter, to be measured using van der Pauw's method. The system is fully automated and is constructed with commercially available components. Measurements of the electrical properties of doped and undoped Si-Ge thin films, grown by liquid phase epitaxy reported here, are to illustrate the capabilities of the apparatus

    Controls on Cyclic Formation of Quaternary Early Diagenetic Dolomite

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    The origin of sedimentary dolomite and the factors that control its formation within the geological record remain speculative. In most models, dolomite formation is linked to evaporative conditions, high water temperature, increasing Mg/Ca ratio, increasing alkalinity, and high amounts of biomass. Here we challenge these archetypal views, by documenting a case example of Quaternary dolomite which formed in Lake Van at constantly low temperature (<4°C) and without direct control of the latter conditions. Dolomite occurs within highstand sediments related to suborbital climate variability (Dansgaard‐Oeschger cycles). We propose that dolomite precipitation is a product of a microbially influenced process, triggered by ecological stress, resulting from reventilation of the water‐sediment interface. Independently from the validity of this hypothesis, our results call for a reevaluation of the paleoenvironmental conditions often invoked for early diagenetic dolomite‐rich intervals within sedimentary sequences and for caution when interpreting time series of subrecent lacustrine carbonates

    Networks among British Immigrants and Accomodation to Canadian Society: Winnipeg, 1900-1914

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    Recently scholars have begun to explain migration in terms of the mechanisms which immigrants employ as groups to accommodate to new societies. Upon arrival in Canada, British immigrants established a new set of social relationships still strongly informed by their pre-emigration culture. The most important social institution facilitating accommodation was the nuclear family. Families were the basis for networks providing reliable information, emotional solace and material support. Other institutions flourishing in British immigrant communities — churches, benefit societies and boarding-houses — functioned as surrogate families. Networks gave the British a competitive advantage in Canada's heterogeneous society. On a commencĂ© Ă  expliquer la migration en terme de mĂ©canismes d’adaptation des groupes d'immigrants. À leur arrivĂ©e au Canada, les immigrants britanniques y ont Ă©tabli un nouveau mode de relations sociales fondĂ© en grande partie, en fait, sur leur culture d’origine. La famille nuclĂ©aire fut la plus importante des institutions sociales facilitant l’adaptation des immigrants. Elle leur fournit des informations provenant de sources fiables, un rĂ©confort affectif et un support matĂ©riel. D’autres institutions fleurissant dans la communautĂ© britannique — les Ă©glises, les sociĂ©tĂ©s de bienfaisance et les maisons d’accueil — fonctionnĂšrent comme des substituts aux familles. Ces rĂ©seaux mirent les britanniques dans une position plus compĂ©titive Ă  l’intĂ©rieur de la sociĂ©tĂ© hĂ©tĂ©rogĂšne canadienne

    Effect of Small Monetary Incentive and Demographic Characteristics on Response Rate of Self-Administered Questionnaire Mailed to Rural Women

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    Objectives: The National Children’s Study (NCS) is a longitudinal observational study that will examine the effects of genetics and environment on the health and development of children in the United States. The NCS is in a Vanguard, or pilot phase, so it is important to determine the feasibility, acceptability and cost of different data collection methods. The purpose of this study was to determine whether demographic characteristics differed in self-administered questionnaire (SAQ) completion rates, and to examine response rates when a 2incentivewasincludedwiththemailedquestionnaire.Methods:Subjectsforthestudy( 500)werebeingfollowedbyalocalcallcenterandweremailedSAQs.Womenwhodidnotcompletetheirlasttelephoneeventwereeligible.Womenwererandomizedtoreceivea2 incentive was included with the mailed questionnaire. Methods: Subjects for the study (~500) were being followed by a local call center and were mailed SAQs. Women who did not complete their last telephone event were eligible. Women were randomized to receive a 2 bill incentive with their SAQ (approximately 250 women in each group). Results: Approximately 450 women comprised the final sample. In the incentive group, 35% of SAQs were returned, which was significantly higher than the 27% returned in the non-incentive group (p\u3c0.001). No significant differences in completion rates based on demographic characteristics were seen, except in divorced women. The final cost per completed SAQ was 12.51intheincentivegroupcomparedto12.51 in the incentive group compared to 7.57 for the non-incentive group. Conclusions: Adding a $2 bill as an incentive significantly increased response rates of hard-to-reach rural women completing mailed questionnaires about pregnancy information. Future research should focus on different incentive amounts and types and how they influence response rates
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