318 research outputs found

    Clamping assembly for inertial components Patent

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    Inertial component clamping assembly design for spacecraft guidance and control system mountin

    Fertilizer production functions for corn and oats; Including an analysis of irrigated and residual response

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    This study includes predictions of fertilizer production functions for four experiments. The experiments on Clarion and McPaul soils contain predictions of total and marginal yields, isoquants and marginal rates of substitution, isoclines and economic optima. Similar analyses for the other two experiments, conducted on Carrington soil during successive growing seasons, were not warranted because insufficient rainfall limited yield responses. The experiments included in this study were based on partially replicated factorial designs. The experiment with corn on Clarion silt loam in 1954 included nitrogen, phosphorus and potash as variable nutrients. The production function, isoquants and isoclines are represented by equations a, b, c, d, e, f and g. In these equations (and equations listed below), N, P and K denote the pounds per acre of nitrogen, P2O5 and K20, respectively. Isoquant and isocline equations were derived for each pair of nutrients. Hence, there are three of each of these equations. The α in the isocline equations represents a constant price or substitution ratio

    Production surfaces and economic optima for corn yields with respect to stand and nitrogen levels

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    This study presents production functions for three experiments on corn in Iowa. It is fourth in a series of studies designed to derive corn response surfaces, yield isoquants and economic optima in fertilizer use.:! It differs from previous studies in that, for the first time, stand (plant population) is included as a variable input along with a plant nutrient (nitrogen). The analysis permits estimation of yield response to stand and to nitrogen as well as to the interaction between stand and nitrogen. Knowledge of this type is relevant, not only for farm recommendations, but also for improved planning of fertilization experiments. The first experiment reported involved stand levels on Shelby loam and was conducted in Ringgold County in 1956. The other two experiments reported were conducted in 1953, with variable stand and nitrogen levels on Marshall and Seymour silt loams, respectively, and were located in Fremont and Wayne counties.3 Each of these experiments included an early and an adapted variety of corn (Iowa 4297 or Iowa 4397 and A.E.S. 801, respectively)

    Demonstration of a Hybrid FSO/VLC Link for the Last Mile and Last Meter Networks

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    OAPA In this paper, a hybrid free-space optical and visible light communication (FSO/VLC) system was experimentally demonstrated as a solution to overcome the last mile and last meter access networks bandwidth bottleneck. We evaluate the system performance of a multiband carrier-less amplitude and phase (m\textit{m}-CAP) modulation scheme for a range of FSO/VLC link lengths and m\textit{m}-CAP parameters (i.e., the roll-off factor of the filters and a number of subcarriers) in terms of the data rate RbR_b (i.e., spectral efficiency). We show that for the configuration with a 1 m VLC link the \mbox{10-CAP} offers more than a 40% improvement in the measured RbR_b compared to 2-CAP for the same bit error rate target. The RbR_b penalty due to the extension of a VLC link span from 1 m to 3 m reaches to 12.6 Mb/s for the \mbox{10-\text{CAP}} scheme (i.e., \sim39% degradation in RbR_b). To fully cover all aspects of the hybrid FSO/VLC system, we also investigate the atmospheric turbulence effect on the 500 m FSO link where RbR_b is decreased by 30% for the refractive index structure parameter Cn2C_n^2 of \mbox{2.4\times10^{\minus15} m^{\minus2/3}} compared to a clear channel condition

    Interplay among transversity induced asymmetries in hadron leptoproduction

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    In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.Comment: 6 figure

    Interplay among transversity induced asymmetries in hadron leptoproduction

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    In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.Comment: 6 figure

    The Spin Structure Function g1pg_1^{\rm p} of the Proton and a Test of the Bjorken Sum Rule

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    New results for the double spin asymmetry A1pA_1^{\rm p} and the proton longitudinal spin structure function g1pg_1^{\rm p} are presented. They were obtained by the COMPASS collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3_3 target. The data were collected in 2011 and complement those recorded in 2007 at 160\,GeV, in particular at lower values of xx. They improve the statistical precision of g1p(x)g_1^{\rm p}(x) by about a factor of two in the region x0.02x\lesssim 0.02. A next-to-leading order QCD fit to the g1g_1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ\Delta \Sigma ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1pg_1^{\rm p}. The uncertainty of ΔΣ\Delta \Sigma is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g1NS(x,Q2)g_1^{\rm NS}(x,Q^2) yields as ratio of the axial and vector coupling constants gA/gV=1.22±0.05 (stat.)±0.10 (syst.)|g_{\rm A}/g_{\rm V}| = 1.22 \pm 0.05~({\rm stat.}) \pm 0.10~({\rm syst.}), which validates the sum rule to an accuracy of about 9\%.Comment: 19 pages, 8 figures and table

    Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

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    A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality Q2>1Q^{2}>1 (GeV/cc)2^2, invariant mass of the hadronic system W>5W > 5 GeV/c2c^2, Bjorken scaling variable in the range 0.003<x<0.40.003 < x < 0.4, fraction of the virtual photon energy carried by the hadron in the range 0.2<z<0.80.2 < z < 0.8, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/c)2<PhT2<3c)^2 < P_{\rm{hT}}^{2} < 3 (GeV/cc)2^2. The multiplicities are presented as a function of PhT2P_{\rm{hT}}^{2} in three-dimensional bins of xx, Q2Q^2, zz and compared to previous semi-inclusive measurements. We explore the small-PhT2P_{\rm{hT}}^{2} region, i.e. PhT2<1P_{\rm{hT}}^{2} < 1 (GeV/cc)2^2, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger PhT2P_{\rm{hT}}^{2}, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small PhT2P_{\rm{hT}}^{2} to study the dependence of the average transverse momentum PhT2\langle P_{\rm{hT}}^{2}\rangle on xx, Q2Q^2 and zz. The power-law behaviour of the multiplicities at large PhT2P_{\rm{hT}}^{2} is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Comment: 28 pages, 20 figure

    Novel baseline predictors of adverse events during oral immunotherapy in children with peanut allergy

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    Though peanut oral immunotherapy (OIT) is a promising investigational therapy, its potential is limited by substantial adverse events (AEs), which are relatively understudied
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