69,534 research outputs found
Lift and drag characteristics of a cabin monoplane
The results of flight tests conducted by the NACA to determine the lift and drag characteristics of a full-scale airplane are given herein. A Fairchild FC-2W2 cabin monoplane having a Gottingen 387 wing section was used for the tests. The maximum lift coefficient for the airplane is compared with that obtained for the Gottingen 387 airfoil in recent tests in the Variable Density Tunnel. The maximum lift coefficient for the airplane was found to be 1.50 and that for the airfoil 1.56. Although the flight tests were confined chiefly to glides with the propeller locked horizontally, data obtained with the propeller operating at zero thrust for a few angles of attack are also included
Investigation of Implantable Multichannel Biotelemetry Systems Semiannual Report, Mar. 1 - Aug. 31, 1966
Integrated-circuit multiplexed telemetry systems for biomedical application
Tiros VII infrared radiation coverage of the 1963 Atlantic hurricane season with supporting television and conventional meteorological data
Infrared radiation data analyzed from Tiros VII SATELLITE coverage of North Atlantic hurricanes during 196
Introduction of Parasites of the Larch Sawfly in Minnesota
Olesicampe benefactor Hinz and the Bavarian strain of Mesoleius tenthredinis Morley, European ichneunionid parasites of the larch sawfly, Pristiphora erichsonii (Hartig), were introduced into northern Minnesota from Manitoba in 1971 and 1972. Both species are now established. There was also natural spread of 0. benefactor into Minnesota from Manitoba releases in 1961 at a point ca. 200 miles northwest of the Minnesota plots
Analysis of the financial factors governing the profitability of lunar helium-3
Financial factors influencing the profitability of the mining and utilization of lunar helium-3 are examined. The analysis addressed the following questions: (1) which financial factors have the greatest leverage on the profitability of He-3; (2) over what range can these factors be varied to keep the He-3 option profitable; and (3) what ultimate effect could this energy source have on the price of electricity for U.S. consumers. Two complementary methods of analysis were used in the assessment: rate of return on incremental investment required and reduction revenue requirements (total cost to customers) achieved. Some of the factors addressed include energy demand, power generation costs with and without fusion, profitability for D-He(3) fusion, annual capital and operating costs, launch mass and costs, He-3 price, and government funding. Specific conclusions are made with respect to each of the companies considered: utilities, lunar mining company, and integrated energy company
Gravity gradient preliminary investigations, part 2: Lunar tidal gravity gradients and stresses (exhibit C)
Preliminary analysis of the gravity gradients associated with gravity tides on the moon caused by the earth indicates that the relative changes in the gradients are very irregular, and large, and about 15 times greater than those experienced on earth. Thus gradients, in preference to gravity tides themselves, may well be an important key in correlating tide effects with lunar transient events and moonquakes, and also in determining triggering mechanisms for crustal movement and faulting. Preliminary analysis of lunar crustal stresses and strains caused by lunar gravity tides indicates that these factors may be more direct causative agents or triggering mechanisms. In particular, the cubic dilation undergoes relatively large changes and is about 11 times greater on the moon than on earth. Thus it should be correspondingly more important
The credibility of health economic models for health policy decision-making: the case of population screening for abdominal aortic aneurysm
<i>Objectives</i>: To review health economic models of population screening for abdominal aortic aneurysm (AAA) among elderly males and assess their credibility for informing decision-making.
<i>Methods</i>: A literature review identified health economic models of ultrasound screening for AAA. For each model focussing on population screening in elderly males, model structure and input parameter values were critically appraised using published good practice guidelines for decision analytic models.
<i>Results</i>: Twelve models published between 1989 and 2003 were identified. Converting costs to a common currency and base year, substantial variability in cost-effectiveness results were revealed. Appraisals carried out for the nine models focusing on population screening showed differences in their complexity, with the simpler models generating results most favourable to screening. Eight of the nine models incorporated two or more simplifying structural assumptions favouring screening; uncertainty surrounding these assumptions was not investigated by any model. Quality assessments on a small number of parameters revealed input values varied between models, methods used to identify and incorporate input data were often not described, and few sensitivity analyses were reported.
<i>Conclusions</i>: Large variation exists in the cost-effectiveness results generated by AAA screening models. The substantial number of factors potentially contributing to such disparities means that reconciliation of model results is impossible. In addition, poor reporting of methods makes it difficult to identify the most plausible and thus most useful model of those developed
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Establishing normative values for 18-35 years age in neuropsychological tests used with head and brain injury patients during cognitive rehabilitation: Benton Visual Retention Test and National Adult Reading Test
The Benton Visual Retention Test (BVRT) is a neuropsychological assessment of visuo-spatial and visuo-memory ability. Claims of high reliability and validity are based on solitary samples representative of a wide age range. This study validated theBVRTagainst the National Adult Reading Test (NART), a highly validated and reliable test of estimated pre-morbid IQ in an age-specific group of participants (18-35 years).
Using Between-subjects factorial design, fifty-three participants (24 female, 29 male) aged 18-35 years (inclusive) were administered the NART and 3 administrations of the BVRT.
Significant positive correlations were found betweenBVRTError scores and NART Error scores for administrations B and C of theBVRTwhich is when presented stimuli are followed by a short time delay before allowing respondents to recall. Significant negative correlations were found over these administrations forBVRTCorrect scores and NART Error scores. No significant relationship was found between depression and performance on theBVRT. However, a weak, non-significant relationship was found between anxiety andBVRTperformance.
The BVRTis a well-validated and highly reliable neuropsychological test of visuo-spatial and visuo-memory abilities. Findings provide new data for the 18-35 years age group as well as providing a cautionary note on the possible influence of anxiety on performance levels in light of the frequent occurrence of anxiety post-neurological injury
Self-gravitating astrophysical mass with singular central density vibrating in fundamental mode
The fluid-dynamical model of a self-gravitating mass of viscous liquid with
singular density at the center vibrating in fundamental mode is considered in
juxtaposition with that for Kelvin fundamental mode in a homogeneous heavy mass
of incompressible inviscid liquid. Particular attention is given to the
difference between spectral formulae for the frequency and lifetime of -mode
in the singular and homogeneous models. The newly obtained results are
discussed in the context of theoretical asteroseismology of pre-white dwarf
stage of red giants and stellar cocoons -- spherical gas-dust clouds with dense
star-forming core at the center.Comment: Mod. Phys. Lett. A, Vol. 24, No. 40 (2009) pp. 3257-327
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