381 research outputs found

    Hydrodynamic and Aerodynamic Tests of a Family of Models of Seaplane Floats with Varying Angles of Dead Rise - N.A.C.A. Models 57-A, 57-B, and 57-C

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    Three models of V-bottom floats for twin-float seaplanes (N.A.C.A. models 57-A, 57-B, and 57-C) having angles of dead rise of 20 degrees, 25 degrees, and thirty degrees, respectively, were tested in the N.A.C.A. tank and in the N.A.C.A. 7- by 10-foot wind tunnel. Within the range investigated, the effect of angle of dead rise on water resistance was found to be negligible at speeds up to and including the hump speed, and water resistance was found to increase with angle of dead rise at planing speeds. The height of the spray at the hump speed decreased with increase in angle of dead rise and the aerodynamic drag increased with dead rise. Lengthening the forebody of model 57-B decreased the water resistance and the spray at speeds below the hump speed. Spray strips provided an effective means for the control of spray with the straight V sections used in the series but considerably increased the aerodynamic drag. Charts for the determination of the water resistance and the static properties of the model with 25 degrees dead rise and for the aerodynamic drag of all the models are included for use in design

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    Development and feasibility testing of a remote support application for adherence to home exercise programs: a randomized pilot study

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    Objectives: Poor adherence to home exercise programs (HEPs) is a significant barrier to continuity of care and eventual outcomes, thus requiring innovative mitigating approaches. This study aimed to develop and test the feasibility of a remote support application (RSA) designed to encourage adherence to HEPs. Methods: Using standard computer programing, an RSA with administrator and user interfaces was developed for mobile phone or tablet. Consenting patients receiving physiotherapy for musculoskeletal conditions (n=19) were randomly assigned into the experimental group (n=10) or the control group (n=9). The experimental group received their customized HEP reminders via the RSA, whereas the control group used conventional paper handouts for HEPs. Adherence to HEPs was assessed over 4 weeks. The feasibility of the RSA was assessed using the Mobile Application Rating Scale and System Usability Scale (SUS) questionnaires. Data were summarized using descriptive and inferential statistics. Results: The adherence rate of patients in experimental group was significantly higher than that of patients in the control group after 2 weeks [median diff.=−6.0, 95% confidence interval (CI): −8.0 to −5.0; U=5.00; Z=−3.304; P=0.001; r=0.75] and 4 weeks (median diff.=−7.0, 95% CI: −8.0 to −5.0; U=0; Z=−3.695; P<0.001; r=0.84) of intervention. The RSA had a mean SUS score of 82.53±9.04 (out of 100) and a mean app quality rating score of 75.95±4.98 (out of 95). Conclusions: The use of an RSA to improve adherence to HEPs is feasible for patients with musculoskeletal conditions

    Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 120 (2015): 2600–2615, doi:10.1002/2014JB011579.The Salton Sea Geothermal Field is one of the most geothermally and seismically active areas in California and presents an opportunity to study the effect of high-temperature metamorphism on the properties of seismogenic faults. The area includes numerous active tectonic faults that have recently been imaged with active source seismic reflection and refraction. We utilize the active source surveys, along with the abundant microseismicity data from a dense borehole seismic network, to image the 3-D variations in seismic velocity in the upper 5 km of the crust. There are strong velocity variations, up to ~30%, that correlate spatially with the distribution of shallow heat flow patterns. The combination of hydrothermal circulation and high-temperature contact metamorphism has significantly altered the shallow sandstone sedimentary layers within the geothermal field to denser, more feldspathic, rock with higher P wave velocity, as is seen in the numerous exploration wells within the field. This alteration appears to have a first-order effect on the frictional stability of shallow faults. In 2005, a large earthquake swarm and deformation event occurred. Analysis of interferometric synthetic aperture radar data and earthquake relocations indicates that the shallow aseismic fault creep that occurred in 2005 was localized on the Kalin fault system that lies just outside the region of high-temperature metamorphism. In contrast, the earthquake swarm, which includes all of the M > 4 earthquakes to have occurred within the Salton Sea Geothermal Field in the last 15 years, ruptured the Main Central Fault (MCF) system that is localized in the heart of the geothermal anomaly. The background microseismicity induced by the geothermal operations is also concentrated in the high-temperature regions in the vicinity of operational wells. However, while this microseismicity occurs over a few kilometer scale region, much of it is clustered in earthquake swarms that last from hours to a few days and are localized near the MCF system.This work was funded by USGS NEHRP proposal G10AP00101 and NSF proposal 0943906.2015-10-2

    Effects of artemether on biochemical markers of liver function in Plasmodium berghei-infected and non-infected rats

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    This study aimed at determining changes in plasma activities of some enzymes and concentrations of plasma organic constituents which are often used in the assessment of liver functions in uninfected rats (UNR) and Plasmodium berghei infected rats (INR), following a week of intramuscular administration of artemether (12.5 to 50.0 mg/kg/day). The observed changes were related to the effects of artemether on the liver of the rats. At all the doses tested, the plasma concentrations of total and conjugated bilirubin increased significantly in both INR and UNR. A significant decrease in the plasma concentrations of glucose was also observed in UNR. The levels of cholesterol were significantly higher in INR than UNR. Plasma glutamate oxaloacetate transaminase (GOT) activity was significantly increased in both categories of rats, but more significantly in INR. The activity of plasma glutamate pyruvate transaminase (GPT) increased significantly at 12.5 and 25.0 mg/kg only in UNR, while a significant increase was observed at 50.0 mg/kg in the INR. Photomicrograph of the liver revealed progressive tissue damage which was more pronounced in INR than UNR. We concluded that high doses of artemether are toxic to the liver of both infected and uninfected rats
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