7,299 research outputs found

    An Analysis of Kinetic Response Variability

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    Studies evaluating variability of force as a function of absolute force generated are synthesized. Inconsistencies in reported estimates of this relationship are viewed as a function of experimental constraints imposed. Typically, within-subject force variability increases at a negative accelerating rate with equal increments in force produced. Current pulse-step and impulse variability models are unable to accommodate this description, although the notion of efficiency is suggested as a useful construct to explain the description outlined

    Cruise aerodynamics of USB nacelle/wing geometric variations

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    Experimental results are presented on aerodynamic effects of geometric variations in upper surface blown nacelle configurations at high speed cruise conditions. Test data include both force and pressure measurements on two and three dimensional models powered by upper surface blowing nacelles of varying geometries. Experimental results are provided on variations in nozzle aspect ratio, nozzle boattail angle, and multiple nacelle installations. The nacelles are ranked according to aerodynamic drag penalties as well as overall installed drag penalties. Sample effects and correlations are shown for data obtained with the pressure model

    Exploratory studies of the cruise performance of upper surface blown configurations: Experimental program, high-speed pressure tests

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    Basic pressure data are presented which was obtained from an experimental study of upper-surface blown configurations at cruise. The high-speed (subsonic) experimental work, studying the aerodynamic effects of wing-nacelle geometric variations, was conducted around semi-span model configurations composed of diversified, interchangeable components. Power simulation was provided by high-pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Both 3-D force and 2-D pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first-order power effects. Results are also presented from a compatibility study in which a short-haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High-lift test data are used to substantiate the projected performance of the selected transport design

    Exploratory studies of the cruise performance of upper surface blown configuration: Experimental program, high-speed force tests

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    The work to develop a wing-nacelle arrangement to accommodate a wide range of upper surface blown configuration is reported. Pertinent model and installation details are described. Data of the effects of a wide range of nozzle geometric variations are presented. Nozzle aspect ratio, boattail angle, and chordwise position are among the parameters investigated. Straight and swept wing configurations were tested across a range of nozzle pressure ratios, lift coefficients, and Mach numbers

    Exploratory studies of the cruise performance of upper surface blown configurations. Experimental program: Test facilities, model design instrumentation, and lowspeed, high-lift tests

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    The model hardware, test facilities and instrumentation utilized in an experimental study of upper surface blown configurations at cruise is described. The high speed (subsonic) experimental work, studying the aerodynamic effects of wing nacelle geometric variations, was conducted around semispan model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Three dimensional force and two dimensional pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first order power effects. Results are also presented from a compatibility study in which a short haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High lift test data are used to substantiate the projected performance of the selected transport design

    Exploratory studies of the cruise performance of upper surface blown configurations

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    The data and major conclusions obtained from an experimental/analytical study of upper-surface blown (USB) configurations at cruise are summarized. The high-speed (subsonic) experimental work, studying the aerodynamic effects of wing-nacelle geometric variations, was conducted around semi-span model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Both 3-D force and 2-D pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first-order power effects. Results are also presented from a compatibility study in which a short-haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High-lift test data are used to substantiate the projected performance of the selected transport design

    Mitoxantrone is superior to doxorubicin in a multiagent weekly regimen for patients older than 60 with high-grade lymphoma: results of a BNLI randomized trial of PAdriaCEBO versus PMitCEBO

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    A prospective, multicenter, randomized trial was undertaken to compare the efficacy and toxicity of adriamycin with mitoxantrone within a 6-drug combination chemotherapy regimen for elderly patients (older than 60 years) with high-grade non-Hodgkin lymphoma (HGL) given for a minimum of 8 weeks. A total of 516 previously untreated patients aged older than 60 years were randomized to receive 1 of 2 anthracycline-containing regimens: adriamycin, 35 mg/m2 intravenously (IV) on day 1 (n = 259), or mitoxantrone, 7 mg/m2 IV on day 1 (n = 257); with prednisolone, 50 mg orally on days 1 to 14; cyclophosphamide, 300 mg/m2 IV on day 1; etoposide, 150 mg/m2 IV on day 1; vincristine, 1.4 mg/m2 IV on day 8; and bleomycin, 10 mg/m2 IV on day 8. Each 2-week cycle was administered for a minimum of 8 weeks in the absence of progression. Forty-three patients were ineligible for analysis. The overall and complete remission rates were 78% and 60% for patients receiving PMitCEBO and 69% and 52% for patients receiving PAdriaCEBO (P = .05, P = .12, respectively). Overall survival was significantly better with PMitCEBO than PAdriaCEBO (P = .0067). However, relapse-free survival was not significantly different (P = .16). At 4 years, 28% of PAdriaCEBO patients and 50% of PMitCEBO patients were alive (P = .0001). Ann Arbor stage III/IV, World Health Organization performance status 2-4, and elevated lactate dehydrogenase negatively influenced overall survival from diagnosis. In conclusion, the PMitCEBO 8-week combination chemotherapy regimen offers high response rates, durable remissions, and acceptable toxicity in elderly patients with HGL

    Soliton response to transient trap variations

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    The response of bright and dark solitons to rapid variations in an expulsive longitudinal trap is investigated. We concentrate on the effect of transient changes in the trap frequency in the form of temporal delta kicks and the hyperbolic cotangent functions. Exact expressions are obtained for the soliton profiles. This is accomplished using the fact that a suitable linear Schrodinger stationary state solution in time can be effectively combined with the solutions of non-linear Schrodinger equation, for obtaining solutions of the Gross-Pitaevskii equation with time dependent scattering length in a harmonic trap. Interestingly, there is rapid pulse amplification in certain scenarios

    Sensation Seeking and Perceived Need for Structure Moderate Soldiers’ Well-Being Before and After Operational Deployment

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    This study examined associations between sensation seeking and perceived need for structure, and changes in reported well-being among deployed soldiers. Participants (n = 167) were assessed before and after a six-month deployment to south Afghanistan. Results indicated that although well-being declined in the soldier sample as a whole following deployment, the degree of decrease was significantly different among soldiers with different personality profiles. Differences were moderated by soldiers’ level of sensation seeking and perceived need for structure. Results are discussed in terms of a person-environment fit theory in the context of preparation and rehabilitation of deployed military personnel

    Self-estimation of Body Fat is More Accurate in College-age Males Compared to Females

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    Objective: To determine the effect of gender on the ability to accurately estimate one’s own body fat percentage. Participants: Fifty-five college-age males and 99 college-age females Methods: Participants estimated their own body fat percent before having their body composition measured using a BOD POD. Participants also completed a modified Social Physique Anxiety Scale (SPAS). Results: Estimated body fat was significantly lower compared to measured body fat percent in females (26.8±5.6% vs. 30.2±7.0%, p\u3c0.001) but not in males (16.8±6.8% vs. 18.1±8.3%, p=0.09). The mean difference between estimated and measured body fat was significantly higher for females compared to males (p\u3c0.001). There was a moderate, significant correlation found between measured body fat percent and SPAS score for males (r=0.331, p=0.014) and females (r=.427, p\u3c0.001). Conclusions: Males estimated their body fat percent more accurately than females. Despite these findings, 62% of males and 76% of females underestimated their body fat
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