296 research outputs found

    Pressurized 1U CubeSat Propulsion System

    Get PDF
    Since the advent of CubeSats, the demand to push mission capabilities of the form-factor has steadily increased. Propulsion systems are one of the driving factors pushing CubeSats towards increasingly complex missions. One propulsion device, an electrothermal plasma thruster known as Pocket Rocket strikes a balance between performance and cost efficiency, in line with the spirit of the CubeSat standard. The thruster has previously been integrated and tested within a 1U CubeSat form factor. However, while functional, the design lacked sufficient propellant storage capability for most missions. To increase propellant storage capability, a 1U CubeSat form factor where the structure itself is a pressure vessel is developed. The Pocket Rocket thruster is embedded into the structure, with batteries, power processing unit (PPU), and propellant regulation and delivery system contained within the pressure vessel. Containing electronic components inside the pressure vessel assists with radiation and thermal protection systems. When used as part of a generic 3U CubeSat mission, the pressurized 1U form factor is capable of producing between 5 and 50 m/s of Δv

    Aquilegia, Vol. 11 No. 5, September 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1036/thumbnail.jp

    Aquilegia, Vol. 11 No. 3, May 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1034/thumbnail.jp

    Aquilegia, Vol. 11 No. 6, November-December 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1037/thumbnail.jp

    Aquilegia, Vol. 11 No. 4, July 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1035/thumbnail.jp

    Aquilegia, Vol. 11 No. 2, March 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1033/thumbnail.jp

    Colorado Native Plant Society Newsletter, Vol. 10 No. 5, November 1986

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1031/thumbnail.jp

    Aquilegia, Vol. 11 No. 1, January 1987: Newsletter of the Colorado Native Plant Society

    Get PDF
    The Colorado Native Plant Society Newsletter will be published on a bimonthly basis. The contents will consist primarily of a calendar of events, notes of interest, editorials, listings of new members and conservation news. Until there is a Society journal, the Newsletter will include short articles also. The deadline for the Newsletter is one month prior to its release.https://epublications.regis.edu/aquilegia/1032/thumbnail.jp

    Dietary Intake and Rural-Urban Migration in India: A Cross-Sectional Study

    Get PDF
    BACKGROUND: Migration from rural areas of India contributes to urbanisation and lifestyle change, and dietary changes may increase the risk of obesity and chronic diseases. We tested the hypothesis that rural-to-urban migrants have different macronutrient and food group intake to rural non-migrants, and that migrants have a diet more similar to urban non-migrants. METHODS AND FINDINGS: The diets of migrants of rural origin, their rural dwelling sibs, and those of urban origin together with their urban dwelling sibs were assessed by an interviewer-administered semi-quantitative food frequency questionnaire. A total of 6,509 participants were included. Median energy intake in the rural, migrant and urban groups was 2731, 3078, and 3224 kcal respectively for men, and 2153, 2504, and 2644 kcal for women (p<0.001). A similar trend was seen for overall intake of fat, protein and carbohydrates (p<0.001), though differences in the proportion of energy from these nutrients were <2%. Migrant and urban participants reported up to 80% higher fruit and vegetable intake than rural participants (p<0.001), and up to 35% higher sugar intake (p<0.001). Meat and dairy intake were higher in migrant and urban participants than rural participants (p<0.001), but varied by region. Sibling-pair analyses confirmed these results. There was no evidence of associations with time in urban area. CONCLUSIONS: Rural to urban migration appears to be associated with both positive (higher fruit and vegetables intake) and negative (higher energy and fat intake) dietary changes. These changes may be of relevance to cardiovascular health and warrant public health interventions

    X-Ray Spectroscopy of Stars

    Full text link
    (abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag
    • …
    corecore