640 research outputs found

    Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

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    Major effort during this reporting period was devoted to two tasks: improvement of the electrical measurement instrumentation through the design and construction of a microcomputer controlled short interval tester, and better understanding of second quadrant behavior by developing a mathematical model relating cell temperature to electrical characteristics. In addition, some preliminary work is reported on an investigation into color changes observed after stressing

    A Comparison of the Diurnal Variation in Lake Surface Temperature for the Five Major Lakes of the Savannah River Basin

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    Satellite measurements of lake surface temperature can benefit several environmental applications such as estimation of lake evaporation, predictions of lake overturning, and meteorological forecasts. Using a one-dimensional lake simulation that incorporates satellite measurements of lake surface temperature, the average diurnal variation in lake surface temperature was obtained. The satellite measurements were obtained from the MODIS instrument aboard the Aqua and Terra satellites. Herein the functional form for the diurnal variation in surface temperature is presented for each of the five major lakes in the Savannah River Basin, which are located in South Carolina and Georgia: Lakes Jocassee, Keowee, Hartwell, Russell, and Thurmond. Differences in the diurnal variation in surface temperature between each of these lakes are identified and potential explanations for these differences are presented

    Martian spectral units derived from ISM imaging spectrometer data

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    Based on results of the Viking mission, the soil layer of Mars has been thought to be fairly homogeneous and to consist of a mixture of as few as two components, a 'dark gray' basaltic material and a 'bright red' altered material. However, near-infrared reflectance spectra measured recently both telescopically and from spacecraft indicate compositional heterogeneity beyond what can be explained by just two components. In particular, data from the ISM imaging spectrometer, which observed much of the equatorial region at a spatial resolution of approximately 22 km, indicate spatial differences in the presence and abundance of Fe-containing phases, hydroxylated silicates, and H2O. The ISM data was used to define, characterize, and map soil 'units' based on their spectral properties. The spatial distribution of these 'units' were compared to morphologic, visible color, and thermal inertia features recognized in Viking data

    Prostate Cancer Survivorship: Prevention and Treatment of the Adverse Effects of Androgen Deprivation Therapy

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    BACKGROUND: More than one-third of the estimated 2 million prostate cancer survivors in the United States receive androgen deprivation therapy (ADT). This population of mostly older men is medically vulnerable to a variety of treatment-associated adverse effects. MEASUREMENTS AND RESULTS: Androgen-deprivation therapy (ADT) causes loss of libido, vasomotor flushing, anemia, and fatigue. More recently, ADT has been shown to accelerate bone loss, increase fat mass, increase cholesterol and triglycerides, and decrease insulin sensitivity. Consistent with these adverse metabolic effects, ADT has also recently been associated with greater risks for fractures, diabetes and cardiovascular disease. CONCLUSION: Primary care clinicians and patients should be aware of the potential benefits and harms of ADT. Screening and intervention to prevent treatment-related morbidity should be incorporated into the routine care of prostate cancer survivors. Evidence-based guidelines to prevent fractures, diabetes, and cardiovascular disease in prostate cancer survivors represent an important unmet need. We recommend the adapted use of established practice guidelines designed for the general population

    Raman effect in AlGaAs waveguides for subpicosecond pulses

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    The Raman effect in semiconductor waveguides below half‐gap is studied both experimentally and numerically. We report the depolarized Raman gain spectra up to 300 cm−1 in Al0.24Ga0.76As at pump wavelengths of 0.515 and 1.55 μm from the measurement of the absolute Raman scattering cross sections using GaAs as a reference scatterer. In addition, the coupled propagation equations for the AlGaAs waveguides are modified to include the Raman effect. By solving the coupled propagation equations numerically, we verify that the energy transfer between two orthogonally polarized pulses demonstrated in previous pump‐probe experiments [M. N. Islam et al., J. Appl. Phys. 71, 1927 (1992)] is caused by Raman effect. We also show numerically that the Raman effect induces spectral distortions on the pulses, and the energy transfer is inversely proportional to the pulse widths. The energy transfer results in a severe cross‐talk problem for sub‐picosecond pulses in AlGaAs waveguides. For example, the energy exchange is about 30% for 300 fs pulses under π phase shift conditions. Therefore, the Raman effect limits the performance of semiconductor waveguides in optical switching applications for sub‐picosecond pulses. © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71265/2/JAPIAU-78-4-2198-1.pd

    Emotional expression during attention-deficit/hyperactivity disorders treatment: initial assessment of treatment effects.

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    OBJECTIVE: The purpose of this research was to provide an initial examination of the effects of atomoxetine and stimulants on emotional expression using a newly developed scale for assessing emotional expression in children with attention-deficit/hyperactivity disorder (ADHD). METHOD: The parent-rated Expression and Emotion Scale for Children (EESC) was collected during two studies. During a cross-sectional validation study, the EESC was completed to assess the child\u27s current treatment and retrospectively for previous medication. In a randomized, placebo-controlled trial of atomoxetine, the EESC was collected at baseline and endpoint. RESULTS: In the validation study, no statistically significant differences in EESC scores were found between groups taking atomoxetine (n = 74) and stimulants (n = 105). Patients who switched from a stimulant to atomoxetine (n = 40) had greater improvement in emotional expression than those switched to another stimulant (n = 21) (p = 0.008). In the clinical trial, no difference in rates of worsening of emotional expression were observed (atomoxetine 8.8%, placebo 12.3%; p = 0.440). CONCLUSION: No treatment differences in emotional expression were observed based on current medications. However, stimulant patients needing to switch medications may have greater improvements in emotional expression by switching to atomoxetine
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