The Health Related Components of Physical Fitness in People with Visual Impairment: A Systematic Review

Visual impairment is becoming progressively more common in America’s aging society. Physical inactivity contributes to the development of chronic health conditions. Therefore, it is important to understand the relationship between visual impairment and its impact on health related physical activity and fitness. The purpose of this systematic review is to examine the prevalence of physical activity and the five components of physical fitness in the visually impaired population. This review was limited to articles addressing individuals with “visual impairment,” as defined by the National Eye Institute. The data abstracted included documentation of visual impairment, physical activity rates, physical fitness measures, gender, age, number of participants, and sample size. Results confirm that persons with visual impairment tend to participate in physical activity significantly less than their sighted counterparts and are often less physically fit, especially in regards to body composition, cardiovascular endurance, and muscular strength. Consensus within the research attributes this decreased physical fitness to the lack of sufficient physical activity within the population. The observed lack of physical activity warrants intentionally improving upon the many physiopsychological and social factors which prevent visually impaired children and adults from having equal access to opportunities to engage regularly in physical fitness activities

Chaotic oscillations in singularly perturbed FitzHugh-Nagumo systems

We consider the singularly perturbed limit of periodically excited two-dimensional FitzHugh-Nagumo systems. We show that the dynamics of such systems are essentially governed by an one-dimensional map and present a numerical scheme to accurately compute it together with its Lyapunov exponent. We then investigate the occurrence of chaos by varying the parameters of the system, with especial emphasis on the simplest possible chaotic oscillations. Our results corroborate and complement some recent works on bifurcations and routes to chaos in certain particular cases corresponding to piecewise linear FitzHugh-Nagumo-like systems.Comment: 16 pages, 6 figures, final version to appear in Chaos, Solitons & Fractal

Development of aircraft brake materials

The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5)

Volume-reflecting dielectric heat shield

White, volume-reflecting dielectric material absorbs essentially none of the incident radiant energy, and continues to reflect even though in severe environment its surface is melted and is being vaporized. Process of overall reflectance in dielectric material, involving internal refractions and reflections, is similar to process of reflection in paints

Meteoroid detector

A meteoroid detector is described which uses, a cold cathode discharge tube with a gas-pressurized cell in space for recording a meteoroid puncture of the cell and for determining the size of the puncture

Solar photochemical process engineering for production of fuels and chemicals

The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6% are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6%. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel

The Effects of Music Genre on Cycling Performance and Perceived Exertion

Many people claim that music enhances their exercise experience. To our knowledge, no studies have analyzed the effect of music genre on exercise performance and perceived effort. Purpose: The purpose of this study was to analyze the effect of music genre on effort as well as perceived exertion while exercising. Methods: Eighteen untrained individuals, age 18-22, participated in this study. Participants performed two 25-minute exercise trials on a Monark bicycle ergometer. Participants were randomized to a music genre (either hip-hop, country or classical) and to condition (music or no music). Rating of perceived exertion (RPE), heart rate (HR), and resistance were recorded for the first ten minutes, while the same three measures and total calories burned were recorded for the final fifteen. Results: No significant difference was found in RPE between music and no music (p=0.477). The results of the Tukey post-hoc showed a significant increase in caloric expenditure between country music and hip-hop music (p=.008). There were no differences in RPE (F2,17=1.45, p=0.265) and music preference (F2,17=3.21, p=0.069) across genre. Conclusion: Based on these results, exercise performance and perceived effort were similar with or without music. When examining the effects of music genre, listening to country music increased caloric expenditure when compared to hip-hop music

Sensing circuits for multiwire proportional chambers

Integrated sensing circuits were designed, fabricated, and packaged for use in determining the direction and fluence of ionizing radiation passing through a multiwire proportional chamber. CMOS on sapphire was selected because of its high speed and low power capabilities. The design of the proposed circuits is described and the results of computer simulations are presented. The fabrication processes for the CMOS on sapphire sensing circuits and hybrid substrates are outlined. Several design options are described and the cost implications of each discussed. To be most effective, each chip should handle not more than 32 inputs, and should be mounted on its own hybrid substrate