3,814 research outputs found

    An evaluation of the ATM man/machine interface. Phase 3: Analysis of SL-3 and SL-4 data

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    The functional adequacy of human factored crew operated systems under operational zero-gravity conditions is considered. Skylab ATM experiment operations generated sufficient telemetry and voice transcript data to support such an assessment effort. Discussions are presented pertaining to the methodology and procedures used to evaluate the hardware, training and directive aspects of Skylab 3 and Skylab 4 manned ATM experiment operations

    CMOS imager for pointing and tracking applications

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    Systems and techniques to realize pointing and tracking applications with CMOS imaging devices. In general, in one implementation, the technique includes: sampling multiple rows and multiple columns of an active pixel sensor array into a memory array (e.g., an on-chip memory array), and reading out the multiple rows and multiple columns sampled in the memory array to provide image data with reduced motion artifact. Various operation modes may be provided, including TDS, CDS, CQS, a tracking mode to read out multiple windows, and/or a mode employing a sample-first-read-later readout scheme. The tracking mode can take advantage of a diagonal switch array. The diagonal switch array, the active pixel sensor array and the memory array can be integrated onto a single imager chip with a controller. This imager device can be part of a larger imaging system for both space-based applications and terrestrial applications

    Anemia in Antiretroviral Naïve HIV/AIDS Patients: A Study from Eastern India

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    Background: Hematological manifestations are common throughout the course of HIV infection. Impact of anemia is the most significant among them. The present study was undertaken to evaluate the etiologies underlying anemia in HIV/AIDS. Methods This was a non randomized cross sectional observational study conducted in a tertiary care hospital of India over a period of 2 years. One hundred and fifty HIV patients were screened. Thorough clinical and laboratory evaluation was done in 50 randomly selected anemic cases. Results: Proper etiological diagnosis could be reached in 46 patients. Among them correlation between Hb% and CD4 count was statistically insignificant (p = 0.074, r = 0.47) whereas it was significant with absolute lymphocyte and CD4 count (p = 0.006, r = 0.41). There was better correlation of bone marrow iron status with percent saturation of transferrin (p = 0.003, r = 0.54) than with serum ferritin (p = 0.055, r = 0.09). Bone marrow iron status did not have any relationship with CD4 count. Anemia of chronic disease was the commonest etiology (37%) followed by HIV related myelodysplastic syndrome (31%), iron deficiency anemia (13%), bone marrow suppression due to direct involvement by some infective process (7%). Aplastic anemia, multiple myeloma, Hodgkin’s disease, pure red cell aplasia, hemophagocytic lymphohistiocytosis and vitamin B12 deficiency were detected in one case (2%) each. Conclusions: Etiologies of anemia in HIV/AIDS are multifactorial with anemia of chronic disease being the commonest. For screening of iron deficiency in this group, percent saturation is a better tool than serum ferritin. Absolute lymphocyte count can sometimes be used as a surrogate marker of immunological status in antiretroviral naïve HIV patients, particularly in resource poor areas

    Isobaric multiplet mass equation in the A=31A=31 T=3/2T = 3/2 quartets

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    The observed mass excesses of analog nuclear states with the same mass number AA and isospin TT can be used to test the isobaric multiplet mass equation (IMME), which has, in most cases, been validated to a high degree of precision. A recent measurement [Kankainen et al., Phys. Rev. C 93 041304(R) (2016)] of the ground-state mass of 31^{31}Cl led to a substantial breakdown of the IMME for the lowest A=31,T=3/2A = 31, T = 3/2 quartet. The second-lowest A=31,T=3/2A = 31, T = 3/2 quartet is not complete, due to uncertainties associated with the identity of the 31^{31}S member state. Using a fast 31^{31}Cl beam implanted into a plastic scintillator and a high-purity Ge γ\gamma-ray detection array, γ\gamma rays from the 31^{31}Cl(βγ)(\beta\gamma)31^{31}S sequence were measured. Shell-model calculations using USDB and the recently-developed USDE interactions were performed for comparison. Isospin mixing between the 31^{31}S isobaric analog state (IAS) at 6279.0(6) keV and a nearby state at 6390.2(7) keV was observed. The second T=3/2T = 3/2 state in 31^{31}S was observed at Ex=7050.0(8)E_x = 7050.0(8) keV. Isospin mixing in 31^{31}S does not by itself explain the IMME breakdown in the lowest quartet, but it likely points to similar isospin mixing in the mirror nucleus 31^{31}P, which would result in a perturbation of the 31^{31}P IAS energy. USDB and USDE calculations both predict candidate 31^{31}P states responsible for the mixing in the energy region slightly above Ex=6400E_x = 6400 keV. The second quartet has been completed thanks to the identification of the second 31^{31}S T=3/2T = 3/2 state, and the IMME is validated in this quartet

    Rape and respectability: ideas about sexual violence and social class

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    Women on low incomes are disproportionately represented among sexual violence survivors, yet feminist research on this topic has paid very little attention to social class. This article blends recent research on class, gender and sexuality with what we know about sexual violence. It is argued that there is a need to engage with classed distinctions between women in terms of contexts for and experiences of sexual violence, and to look at interactions between pejorative constructions of working-class sexualities and how complainants and defendants are perceived and treated. The classed division between the sexual and the feminine, drawn via the notion of respectability, is applied to these issues. This piece is intended to catalyse further research and debate, and raises a number of questions for future work on sexual violence and social class

    Beta-delayed gamma decay of 26P: Possible evidence of a proton halo

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    Background: Measurements of β\beta decay provide important nuclear structure information that can be used to probe isospin asymmetries and inform nuclear astrophysics studies. Purpose: To measure the β\beta-delayed γ\gamma decay of 26^{26}P and compare the results with previous experimental results and shell-model calculations. Method: A 26^{26}P fast beam produced using nuclear fragmentation was implanted into a planar germanium detector. Its β\beta-delayed γ\gamma-ray emission was measured with an array of 16 high-purity germanium detectors. Positrons emitted in the decay were detected in coincidence to reduce the background. Results: The absolute intensities of 26^{26}P β\beta-delayed γ\gamma-rays were determined. A total of six new β\beta-decay branches and 15 new γ\gamma-ray lines have been observed for the first time in 26^{26}P β\beta-decay. A complete β\beta-decay scheme was built for the allowed transitions to bound excited states of 26^{26}Si. ftft values and Gamow-Teller strengths were also determined for these transitions and compared with shell model calculations and the mirror β\beta-decay of 26^{26}Na, revealing significant mirror asymmetries. Conclusions: A very good agreement with theoretical predictions based on the USDB shell model is observed. The significant mirror asymmetry observed for the transition to the first excited state (δ=51(10)%\delta=51(10)\%) may be evidence for a proton halo in 26^{26}P.Comment: 15 pages, 10 figures, 7 table

    Cosmology from Type Ia Supernovae

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    This presentation reports on first evidence for a low-mass-density/positive-cosmological-constant universe that will expand forever, based on observations of a set of 40 high-redshift supernovae. The experimental strategy, data sets, and analysis techniques are described. More extensive analyses of these results with some additional methods and data are presented in the more recent LBNL report #41801 (Perlmutter et al., 1998; accepted for publication in Ap.J.), astro-ph/9812133 . This Lawrence Berkeley National Laboratory reprint is a reduction of a poster presentation from the Cosmology Display Session #85 on 9 January 1998 at the American Astronomical Society meeting in Washington D.C. It is also available on the World Wide Web at http://supernova.LBL.gov/ This work has also been referenced in the literature by the pre-meeting abstract citation: Perlmutter et al., B.A.A.S., volume 29, page 1351 (1997).Comment: 9 pages, 8 color figs. Presented at Jan '98 AAS Meeting, also cited as BAAS,29,1351(1997). Archived here in response to requests; see more extensive analyses in ApJ paper (astro-ph/9812133

    24^{24}Mg(pp, α\alpha)21^{21}Na reaction study for spectroscopy of 21^{21}Na

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    The 24^{24}Mg(pp, α\alpha)21^{21}Na reaction was measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to better constrain spins and parities of energy levels in 21^{21}Na for the astrophysically important 17^{17}F(α,p\alpha, p)20^{20}Ne reaction rate calculation. 31 MeV proton beams from the 25-MV tandem accelerator and enriched 24^{24}Mg solid targets were used. Recoiling 4^{4}He particles from the 24^{24}Mg(pp, α\alpha)21^{21}Na reaction were detected by a highly segmented silicon detector array which measured the yields of 4^{4}He particles over a range of angles simultaneously. A new level at 6661 ±\pm 5 keV was observed in the present work. The extracted angular distributions for the first four levels of 21^{21}Na and Distorted Wave Born Approximation (DWBA) calculations were compared to verify and extract angular momentum transfer.Comment: 11 pages, 6 figures, proceedings of the 18th International Conference on Accelerators and Beam Utilization (ICABU2014
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