1,037 research outputs found

    Photovoltaic power systems workshop

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    Discussions are presented on apparent deficiencies in NASA planning and technology development relating to a standard power module (25-35 kW) and to future photovoltaic power systems in general. Topics of discussion consider the following: (1) adequate studies on power systems; (2) whether a standard power system module should be developed from a standard spacecraft; (3) identification of proper approaches to cost reduction; (4) energy storage avoidance; (5) attitude control; (6) thermal effects of heat rejection on solar array configuration stability; (7) assembly of large power systems in space; and (8) factoring terrestrial photovoltaic work into space power systems for possible payoff

    Time-dependent gravity in southern California, May 1974 - Apr 1979

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    Gravity measurements were coordinated with the long baseline three dimensional geodetic measurements of the Astronomical Radio Interferometric Earth Surveying project which used radio interferometry with extra-galactic radio sources. Gravity data from 28 of the stations had a single reading standard deviation of 11 microgal which gives a relative single determination between stations a standard deviation of 16 microgal. The largest gravity variation observed, 80 microgal, correlated with nearby waterwell variations and with smoothed rainfall. Smoothed rainfall data appeared to be a good indicator of the qualitative response of gravity to changing groundwater levels at other suprasediment stations, but frequent measurement of gravity at a station was essential until the quantitative calibration of the station's response to groundwater variations was accomplished

    Emotion Regulation and Perceptions of Illness Coherence and Controllability on Regimen Adherence and Negative Cardiac Health Events in African American Women With Heart Failure

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    Background: African American women with heart failure (HF) have stressors that negatively impact HF self-management adherence and heighten the occurrence of negative cardiac health events. Perceptions of illness coherence and controllability and emotion regulation are known to facilitate self-management in the face of stressors. Objective: The aim of this study was to determine whether difficulties with emotion regulation and negative perceptions of illness coherence and controllability are detrimental to adherence and increase negative cardiac health events in this patient population. Methods: African American women (n = 54) with HF, aged 49 to 84 years, participated in this longitudinal descriptive correlational study. Using convenience sampling, we recruited patients from hospitals and HF clinics. They completed interviews at intake and 30 days, and their medical records were reviewed at 90 days. Linear and logistic regression models were used to assess predictors of general adherence and negative cardiac health events. Results: Of 54 patients who participated in the study, 28 experienced a negative health event during 90 days, and 57% of these events were cardiac related. The only clear predictor of these events was greater New York Heart Association functional classification (β = 1.47, P = .027). No associations were found between predictors (emotion regulation, controllability, coherence, age, education) and general adherence. Conclusions: Emotion regulation showed a possible greater impact on negative cardiac health events than on general adherence. Perceived illness coherence showed less impact on negative cardiac health events than on general adherence

    Emotion Regulation in Chronic Disease Populations: An Integrative Review

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    Background and Purpose: Emotion regulation, the experiencing, processing, and modulating of emotional response, is necessary to manage the emotional stressors common in patients with chronic illness. Overwhelming emotional demands deplete the resources needed for everyday self-care management of chronic disease, contributing to poor health outcomes. Emotion regulation is shown to impact behaviors in healthy individuals; yet, a review of literature examining evidence of associations in chronically ill populations is lacking. The purpose of this article is to examine the state of the science relative to the impact of emotion regulation on health outcomes in chronic illness populations. Methods: Articles were reviewed (N = 14) that focused on emotion regulation and outcomes of patients with chronic illness. Results: Indicate that most of the studies focused on these concepts are cross-sectional and measure emotion regulation using various surveys. Potential relationships exist with increased age, male gender, higher education, decreased stress, depressive, and anxiety symptoms being associated with more adaptive emotion regulation. Of primary importance to patients with chronic illnesses is the potential link between greater difficulties with emotion regulation and the presence of chronic disease as well as poorer physical function. Implications for Practice: Care should include attention to affective regulation as well as physiologic responses of chronic illness

    An evaluation of preoperative CA 15-3 measurement in primary breast carcinoma.

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    In this study of 500 patients with breast carcinoma, we have prospectively assessed the role of preoperative CA 15-3 as a marker of disease burden over a 7 year period. CA 15-3 levels at presentation correlate with stage of disease, tumour size, lymph node status, the presence of metastases and lymphocyte infiltration into the tumour. CA 15-3 alone is not an independent prognostic indicator, although a serum level of > 40 U ml-1 has a positive predictive value of 83% for the presence of advanced disease. We recommend the routine use of this marker in the preoperative assessment of primary breast carcinoma

    Theory of continuum percolation III. Low density expansion

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    We use a previously introduced mapping between the continuum percolation model and the Potts fluid (a system of interacting s-states spins which are free to move in the continuum) to derive the low density expansion of the pair connectedness and the mean cluster size. We prove that given an adequate identification of functions, the result is equivalent to the density expansion derived from a completely different point of view by Coniglio et al. [J. Phys A 10, 1123 (1977)] to describe physical clustering in a gas. We then apply our expansion to a system of hypercubes with a hard core interaction. The calculated critical density is within approximately 5% of the results of simulations, and is thus much more precise than previous theoretical results which were based on integral equations. We suggest that this is because integral equations smooth out overly the partition function (i.e., they describe predominantly its analytical part), while our method targets instead the part which describes the phase transition (i.e., the singular part).Comment: 42 pages, Revtex, includes 5 EncapsulatedPostscript figures, submitted to Phys Rev

    Electromechanical forces acting on bio-membranes in external electric fields

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    Membranes of microorganisms stressed with electric field can be deformed and ruptured due to unbalanced electro-mechanical forces. The paper provides an analytical analysis of the forces acting on bio-membranes in liquid and gaseous environment. This model can help in optimisation and further development of novel field and plasma based decontamination methods

    Mental Health Outcomes during Colorectal Cancer Survivorship: A Review of the Literature

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    Objective This article reviews literature on adults’ mental health outcomes during acute and long-term colorectal cancer (CRC) survivorship. Methods We identified articles that included at least one measure of psychological symptoms or mental quality of life or well-being through a search of databases (CINAHL, MEDLINE, PsycINFO, and PsycARTICLES). Articles were published between January 2004 and April 2015. Results A significant proportion of CRC survivors experience clinically meaningful levels of anxiety and depressive symptoms or reduced mental well-being across the trajectory of the illness. Demographic, medical, and psychosocial predictors of mental health outcomes were identified. However, few studies were theory-driven, and gaps remain in our understanding of risk and protective factors with respect to mental health outcomes, especially during long-term CRC survivorship. Conclusions Theory-driven longitudinal research with larger samples is required to identify subgroups of CRC survivors with different trajectories of psychological adjustment. Such research would assess adjustment as a function of internal resources (e.g., personality, coping) and external resources (e.g., finances, social support) to inform future interventions for CRC survivors

    Green Function on the q-Symmetric Space SU_q(2)/U(1)

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    Following the introduction of the invariant distance on the non-commutative C-algebra of the quantum group SU_q(2), the Green function and the Kernel on the q-homogeneous space M=SU(2)_q/U(1) are derived. A path integration is formulated. Green function for the free massive scalar field on the non-commutative Einstein space R^1xM is presented.Comment: Plain Latex, 19
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