889 research outputs found

    European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0

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    The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with speciïŹ c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of speciïŹ cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and speciïŹ c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag

    A Geology Sampling System for Small Bodies

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    Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are being discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a small body. Currently, the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution

    Underascertainment of radiotherapy receipt in Surveillance, Epidemiology, and End Results registry data

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    BACKGROUND: Surveillance, Epidemiology, and End Results (SEER) registry data have been used to suggest underuse and disparities in receipt of radiotherapy. Prior studies have cautioned that SEER may underascertain radiotherapy but lacked adequate representation to assess whether underascertainment varies by geography or patient sociodemographic characteristics. The authors sought to determine rates and correlates of underascertainment of radiotherapy in recent SEER data. METHODS: The authors evaluated data from 2290 survey respondents with nonmetastatic breast cancer, aged 20 to 79 years, diagnosed from June of 2005 to February 2007 in Detroit and Los Angeles and reported to SEER registries (73% response rate). Survey responses regarding treatment and sociodemographic factors were merged with SEER data. The authors compared radiotherapy receipt as reported by patients versus SEER records. The authors then assessed correlates of radiotherapy underascertainment in SEER. RESULTS: Of 1292 patients who reported receiving radiotherapy, 273 were coded as not receiving radiotherapy in SEER (underascertained). Underascertainment was more common in Los Angeles than in Detroit (32.0% vs 11.25%, P < .001). On multivariate analysis, radiotherapy underascertainment was significantly associated in each registry (Los Angeles, Detroit) with stage ( P = .008, P = .026), income ( P < .001, P = .050), mastectomy receipt ( P < .001, P < .001), chemotherapy receipt ( P < .001, P = .045), and diagnosis at a hospital that was not accredited by the American College of Surgeons ( P < .001, P < .001). In Los Angeles, additional significant variables included younger age ( P < .001), nonprivate insurance ( P < .001), and delayed receipt of radiotherapy ( P < .001). CONCLUSIONS: SEER registry data as currently collected may not be an appropriate source for documentation of rates of radiotherapy receipt or investigation of geographic variation in the radiation treatment of breast cancer. Cancer 2011;. © 2011 American Cancer Society. This study found that the Los Angeles Cancer Surveillance Program, among the largest Surveillance, Epidemiology, and End Results (SEER) registries, coded that radiation was not received in nearly a third of cases in which breast cancer patients themselves reported radiation receipt, whereas ascertainment of radiation receipt was much more complete in another large SEER registry, that of the Metropolitan Detroit Cancer Surveillance System. SEER registry data as currently collected may not be an appropriate source for documentation of rates of radiotherapy receipt or geographic disparities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90319/1/26295_ftp.pd

    Towards an Architectural Definition of Normalization: Design Principles for Housing Severely and Profoundly Retarded Adults.

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    Center for Urban and Regional Affairs, School of Architecture and Landscape Architecture, Department of Psychology, and the Graduate School, University of Minnesota

    Social Media Use: Attitudes, "Detox," and Craving in Typical and Frequent Users

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    Social media has become a core feature of daily life, with 4.8 billion users worldwide. Research on individual differences in social media use has tended to focus on the effect of differing levels of engagement on specific mental health outcomes. In contrast, few studies have directly investigated users’ own perceptions of the impact of their social media use, attempts to regulate their behavior through periods of “detox,” and the drivers that compel them to return to these platforms. Therefore, in this study, we examined users’ current attitudes toward their social media use, their awareness of the impact it had on other aspects of their lives, their experiences of self-initiated periods of “detox,” and their reasons for reengagement. A sample of 208 U.K. social media users (aged 18–28), partitioned into typical and frequent user groups using the Social Media Addiction Questionnaire and the Social Media Engagement Questionnaire, were tested on all measures. The findings, derived from both quantitative and qualitative data, showed that users across both groups were aware of the impact of overuse, and they were able to successfully engage in sustained periods of social media detox, from which they derived positive effects (e.g., on sleep, mood, productivity), and the primary driver for continued use was a desire for social connectedness and information rather than a “craving” for social media per se. Taken together, these findings provide novel data on users’ perceptions of their social media use and, in particular, evidence in support of the positive benefits of periods of social media “detox.

    Visible and Near-IR Reflectance Spectra of Smectite Acquired Under Dry Conditions for Interpretation of Martian Surface Mineralogy

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    Visible and near-IR (VNIR) spectra from the MEx OMEGA and the MRO CRISM hyper-spectral imaging instruments have spectral features associated with the H2O molecule and M OH functional groups (M = Mg, Fe, Al, and Si). Mineralogical assignments of martian spectral features are made on the basis of laboratory VNIR spectra, which were often acquired under ambient (humid) conditions. Smectites like nontronite, saponite, and montmorillionite have interlayer H2O that is exchangeable with their environment, and we have acquired smectite reflectance spectra under dry environmental conditions for interpretation of martian surface mineralogy. We also obtained chemical, Moessbauer (MB), powder X-ray diffraction (XRD), and thermogravimetric (TG) data to understand variations in spectral properties. VNIR spectra were recorded in humid lab air at 25-35C, in a dynamic dry N2 atmosphere (50-150 ppmv H2O) after exposing the smectite samples (5 nontronites, 3 montmorillionites, and 1 saponite) to that atmosphere for up to approximately l000 hr each at 25-35C, approximately 105C, and approximately 215C, and after re-exposure to humid lab air. Heating at 105C and 215C for approximately 1000 hr is taken as a surrogate for geologic time scales at lower temperatures. Upon exposure to dry N2, the position and intensity of spectral features associated with M-OH were relatively insensitive to the dry environment, and the spectral features associated with H2O (e.g., approximately 1.90 micrometers) decreased in intensity and are sometimes not detectable by the end of the 215C heating step. The position and intensity of H2O spectral features recovered upon re-exposure to lab air. XRD data show interlayer collapse for the nontronites and Namontmorillionites, with the interlayer remaining collapsed for the latter after re-exposure to lab air. The interlayer did not collapse for the saponite and Ca-montmorillionite. TG data show that the concentration of H2O derived from structural OH was invariant to the dry N2 treatment for saponite and the montmorillionites, but the nontronites had additional structural OH after treatment. Upon exposure to dry N2, the VNIR spectra also acquired a red slope with decreasing albedo between approximately 0.4 and approximately 2.0 micrometers. The magnitude of the effects covaries with exposure time to dry N2 and heating temperature. Upon re-exposure to lab air, the slope and albedo do not completely recover to pre-exposure values. MB data show that these effects do not result from partial reduction of ferric to ferrous iron, and TG data show they do not result from loss of structural OH. Possible explanations include formation of small clusters of (superparamagnetic) ferric oxide and reduced smectite crystallinity. The difference in spectral properties between spectra acquired in humid lab air and under dry conditions are consequential for interpretation of CRISM and OMEGA spectra. For example, nontronite by itself and not nontronite plus ferrihydrite can account for the red spectral slope in martian spectra where nontronite is indicated by the Fe-OH spectral features
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