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Refractive index - Particle density nonequilibrium cesium plasmas probed by a multifrequency helium-neon laser

Refractive index computation for free electrons and neutral atoms in cesium plasma at helium neon laser wavelength

Computer-acquired performance map of an etched-rhenium, niobium planar diode

Computer acquired performance map of etched-rhenium, niobium planar diod

Design and Finite Element Analysis of Mixed Aerofoil Wind Turbine Blades

Wind turbine technology is one of the rapid growth sectors of renewable energy all over the world. As a core component of a wind turbine, it is a common view that the design and manufacturing of rotor blades represent about 20% of the total investment of the wind turbine [1]. Moreover, the performance of a wind turbine is highly dependent on the design of the rotor [2]. As well as rotor aerodynamic performance, the structure strength, stiffness and fatigue of the blade are also critical to the wind turbine system service life. This paper presents the design and Finite Element Analysis (FEA) of a 10KW fixed-pitch variable-speed wind turbine blade with five different thickness of aerofoil shape along the span of the blade. The main parameters of the wind turbine rotor and the blade aerodynamic geometry shape are determined based on the principles of the blade element momentum (BEM) theory. Based on the FE method, deflections and strain distributions of the blade under extreme wind conditions are numerically predicted. The results indicate that the tip clearance is sufficient to prevent collision with the tower, and the blade material is linear and safe

Comparison of computer-acquired performance data from several fixed spaced planar diodes

Comparison of performance data envelopes for thermionic diodes with various tungsten or rhenium emitters and niobium or molybdenum collector

Distribution of E/N and N sub e in a cross-flow electric discharge laser

The spatial distribution of the ratio of electric field to neutral gas density on a flowing gas, multiple pin-to-plane discharge was measured in a high-power, closed loop laser. The laser was operated at a pressure of 140 torr (1:7:20, CO2, N2, He) with typically a 100 meter/second velocity in the 5 x 8 x 135 centimeter discharge volume. E/N ratios ranged from 2.7 x 10 to the minus 16th power to 1.4 x 10 to the minus 16th power volts/cu cm along the discharge while the electron density ranged from 2.8 x 10 to the 10th power to 1.2 x 10 to the 10th power cm/3

Computer acquired performance data from a chemically vapor-deposited-rhenium, niobium planar diode

Performance data from a chemically vapor-deposited-rhenium, niobium thermionic converter are presented. The planar converter has a guard-ringed collector and a nominal fixed spacing of 0.25 mm (10 mils). The data were obtained by using a computerized acquisition system and are available on request to one of the authors on microfiche as individual and composite parametric current, voltage curves. The parameters are the temperatures of the emitter T sub E collector T sub C, and cesium reservoir T sub R. The composite plots have constant T sub E and varying T sub C or T sub R, or both. Current, voltage envelopes having constant T sub E with and without fixed T sub C appear in the present report. The diode was tested at increments between 1600 and 2000 K for the emitter Hohlraum, 800 to 1100 K for the collector, and 540 and 650 K for the reservoir. A total of 312 current, voltage curves were obtained in the present performance evaluation. Current, voltage envelopes from three rhenium emitter converters evaluated in the present program are also given. The data are compared at commom emitter Hohlraum temperatures

New postnatal urinary incontinence: obstetric and other risk factors in primparae.

Objective To identify obstetric and other risk factors for urinary incontinence which occurs during pregnancy or after childbirth. Design Questionnaire survey of women. Setting Maternity units in Aberdeen (Scotland), Birmingham (England) and Dunedin (New Zealand). Population 3405 primiparous women with singleton births delivered during one year. Methods Questionnaire responses and obstetric casenote data were analysed using multivariate analysis to identify associations with urinary incontinence. Main outcome measures Urinary incontinence at three months after delivery first starting in pregnancy or after birth. Results The prevalence of urinary incontinence was 29%. New incontinence first beginning after delivery was associated with higher maternal age (oldest versus youngest group, odds ratio, OR 2.02, 95% CI 1.35 to 3.02); and method of delivery (caesarean section versus spontaneous vaginal delivery, OR 0.28, 95% CI 0.19 to 0.41). There were no significant associations with forceps delivery (OR 1.18, 95% CI 0.92 to 1.51) or vacuum delivery (OR 1.16, 95% CI 0.83 to 1.63). Incontinence first occurring during pregnancy and still present at three months was associated with higher maternal body mass index (BMI > 25, OR 1.68, 95% CI 1.16 to 2.43), and heavier babies (birthweight in top quartile, OR 1.56, 95% CI 1.12 to 2.19). In these women, caesarean section was associated with less incontinence (OR 0.39, 95% CI 0.27 to 0.58) but incontinence was not associated with age. Conclusions Women have less urinary incontinence after a first delivery by caesarean section whether or not that first starts during pregnancy. Older maternal age was associated with new postnatal incontinence, and higher body mass index and heavier babies with incontinence first starting during pregnancy. The effect of further deliveries may modify these findings