2,060 research outputs found
On the Use of a Magnetometer to Determine the Angular Motion of a Spinning Body in Regular Precession
Magnetometer for determination of angular motion of spinning body in regular precessio
A method for determining nodal arrival times at the moon from precessing near-earth parking orbits having various inclinations
Effect of precession of near-earth orbits on timing of inplane launching for nodal encounter with moo
Radiation resistance of Ge, Ge0.93Si0.07, GaAs and Al0.08Ga0.92 as solar cells
Solar cells made of Ge, Ge(0.93)Si(0.07) alloys, GaAs and Al(0.08)Ga(0.92)As were irradiated in two experiments with 1-meV electrons at fluences as great as 1 x 10(exp 16) cm(exp-2). Several general trends have emerged. Low-band-gap Ge and Ge(0.93)Si(0.07) cells show substantial resistance to radiation-induced damage. The two experiments showed that degradation is less for Al(0.08)Ga(0.92)As cells than for similarly irradiated GaAs cells. Compared to homojunctions, cells with graded-band-gap emitters did not show the additional resistance to damage in the second experiment that had been seen in the first. The thickness of the emitter is a key parameter to limit the degradation in GaAs devices
Biomarkers of browning of white adipose tissue and their regulation during exercise- and diet-induced weight loss
Background: A hypothesis exists whereby an exercise- or dietary-induced negative energy balance reduces human subcutaneous white adipose tissue (scWAT) mass through the formation of brown-like adipocyte (brite) cells. However, the validity of biomarkers of brite formation has not been robustly evaluated in humans, and clinical data that link brite formation and weight loss are sparse. Objectives: We used rosiglitazone and primary adipocytes to stringently evaluate a set of biomarkers for brite formation and determined whether the expression of biomarker genes in scWAT could explain the change in body composition in response to exercise training combined with calorie restriction in obese and overweight women (n = 79). Design: Gene expression was derived from exon DNA microarrays and preadipocytes from obesity-resistant and -sensitive mice treated with rosiglitazone to generate candidate brite biomarkers from a microarray. These biomarkers were evaluated against data derived from scWAT RNA from obese and overweight women before and after supervised exercise 5 d/wk for 16 wk combined with modest calorie restriction (∼0.84 MJ/d). Results: Forty percent of commonly used brite gene biomarkers exhibited an exon or strain-specific regulation. No biomarkers were positively related to weight loss in human scWAT. Greater weight loss was significantly associated with less uncoupling protein 1 expression (P = 0.006, R(2) = 0.09). In a follow-up global analysis, there were 161 genes that covaried with weight loss that were linked to greater CCAAT/enhancer binding protein α activity (z = 2.0, P = 6.6 × 10(−7)), liver X receptor α/β agonism (z = 2.1, P = 2.8 × 10(−7)), and inhibition of leptin-like signaling (z = −2.6, P = 3.9 × 10(−5)). Conclusion: We identify a subset of robust RNA biomarkers for brite formation and show that calorie-restriction–mediated weight loss in women dynamically remodels scWAT to take on a more-white rather than a more-brown adipocyte phenotype
Recovery of Point-Injected Labeled Nitrogen by Corn as Affected by Timing, Rate, and Tillage
Point-injection technology is being developed to improve fertilizer management, particularly N management. This study was conducted to evaluate the effects of the rate (number) and timing of point-injections of an ammonium nitrate (NH4NO3) solution on N uptake and corn growth and to measure any differences due to tillage. Nitrogen-15 depleted NH4NO3 (AN) was hand-injected beside individual plants at the V1, V5, and/or V9 growth stages at rates of 50, 100, and/or 200 kg N ha−1 with fall moldboard plow (MP), fall chisel plow (CP), and ridge-till (RT) systems. While MP had the highest grain and total dry matter production (but with the lowest N concentrations in those materials), tillage was not a significant factor in either the percentage of the total plant N derived from labeled AN (NF) or its recovery (NR) for any stage sampled. Generally the year (i.e. different environmental conditions) and application timing or a timing-by-year interaction had the greatest influence on NF and NR. Although plants sampled at the V9 stage on the average recovered more N from the V1 application (39%) vs the V5 application (27%), at maturity NR values for grain (35%) and total dry matter (47%) were the same for both V1 or V5 applications (when only two applications were made). However when three applications were made (at the V1, V5, and V9 stages), NR values decreased with time of application for both grain (38, 31, and 26%, respectively) and total dry matter (53, 43, and 33%, respectively). Across application timing, grain NR values were 34 and 31%, respectively, for MP and RT. Compared with preplant knifed-in labeled N for MP and RT systems in an adjacent simultaneous study, grain NRvalues for point-injected N in this study were 16 and 6% greater, respectively, indicating that multiple injections of fertilizer N improved N-use efficiency
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US and UK Routes to Employment: Strategies to Improve Integrated Service Delivery to People with Disabilities
In this report, the authors examine the experience of the United States and United Kingdom in developing effective strategies for providing integrated service delivery. The report examines what works and what doesn't work, and provides a roadmap to improving services for individuals with disabilities. While more research is needed, the report identifies 12 strategies to strengthen integrated service delivery systems, and to assist individuals with disabilities in gaining and maintaining productive employment. Implementing these strategies can benefit clients, who have the opportunity to realize their potential more fully; the taxpayer, who is paying less for disability assistance; and society at large, which gains the productive skill of talented individuals
Soil erosion and some means for its control
The control of soil erosion on the many farms where it is still a problem would not be difficult if it required only an understanding of the critical physical relationships between climate, topography, plant cover, water and soil as well as an ability to prescribe the proper engineering and agronomic measures for each situation. Soil losses, when greatly in excess of those produced by natural geological processes, result from the use of particular farming practices and cropping systems. While an understanding of the physical conditions which produce this erosion is essential, so is an understanding of the reasons that farmers choose the methods of farming which expose their soil to the hazard of heavy erosion losses.https://lib.dr.iastate.edu/specialreports/1027/thumbnail.jp
Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFeAs
The iron-based high temperature superconductors exhibit a rich phase diagram
reflecting a complex interplay between spin, lattice, and orbital degrees of
freedom [1-4]. The nematic state observed in many of these compounds epitomizes
this complexity, by entangling a real-space anisotropy in the spin fluctuation
spectrum with ferro-orbital order and an orthorhombic lattice distortion [5-7].
A more subtle and much less explored facet of the interplay between these
degrees of freedom arises from the sizable spin-orbit coupling present in these
systems, which translates anisotropies in real space into anisotropies in spin
space. Here, we present a new technique enabling nuclear magnetic resonance
under precise tunable strain control, which reveals that upon application of a
tetragonal symmetry-breaking strain field, the magnetic fluctuation spectrum in
the paramagnetic phase of BaFeAs also acquires an anisotropic
response in spin-space. Our results unveil a hitherto uncharted internal spin
structure of the nematic order parameter, indicating that similar to liquid
crystals, electronic nematic materials may offer a novel route to
magneto-mechanical control.Comment: 11 pages, 5 figure
Graded-bandgap AlGaAs solar cells for AlGaAs/Ge cascade cells
Some p/n graded-bandgap Al(x)Ga(1-x)As solar cells were fabricated and show AMO conversion efficiencies in excess of 15 percent without antireflection (AR) coatings. The emitters of these cells are graded between 0.008 is less than or equal to x is less than or equal to 0.02 during growth of 0.25 to 0.30 micron thick layers. The keys to achieving this performance were careful selection of organometallic sources and scrubbing oxygen and water vapor from the AsH3 source. Source selection and growth were optimized using time-resolved photoluminescence. Preliminary radiation-resistance measurements show AlGaAs cells degraded less than GaAs cells at high 1 MeV electron fluences, and AlGaAs cells grown on GaAs and Ge substrates degrade comparably
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