6,067 research outputs found

    Kinesimetric method and apparatus

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    Apparatus and method for the determination of functional capability of bodies are disclosed. Reach as well as velocity, acceleration and force generation at various positions may be determined for a body by a three dimensional kinesimeter equipped with an ergometer. A general data package indicative of performance potential of a subject body or collection of bodies is provided for interfacing with data characteristics of various environments

    Method and apparatus for simulating gravitational forces on a living organism

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    A method and apparatus for simulating gravitational forces on a living organism wherein a series of negative pressures are externally applied to successive length-wise sections of a lower limb of the organism. The pressures decreasing progressively with distance of said limb sections from the heart of the organism. A casing defines a chamber adapted to contain the limb of the organism and is rigidified to resist collapse upon the application of negative pressures to the interior of the chamber. Seals extend inwardly from the casing for effective engagement with the limb of the organism and, in cooperation with the limb, subdivide the chamber into a plurality of compartments each in negative pressure communicating relation with the limb

    Hemodynamic studies of the legs under weightlessness

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    Following exposure to weightlessness, alterations in the return of blood from the legs play a crucial role in orthostatic tolerance and may be an important factor in work tolerance. To investigate some of the hemodynamic mechansism involved, an experiment was performed on the Skylab 3 and Skylab 4 missions to study arterial blood flow, venous compliance, and muscle pumping of blood. Skylab 4 results indicated that the most likely cause of increased blood flow was an increase in cardiac output secondary to increased central venous pressure caused by blood redistribution. Changes in venous compliance are thought to be primarily changes in somatic musculature which is postulated to primarily determine venous compliance of the legs. This was also thought to be demonstrated by the changes in muscle pumping. It is thought that these compliance changes, when taken with the decreased blood volume; provide a basis for the changes seen in orthostatic tolerance, work capacity and lower body negative pressure response

    Improved method and apparatus for waste collection and storage

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    A method and apparatus for the collection of fecal matter are designed to operate efficiently in a zero gravity environment. The system comprises a waste collection area within a body having a seat opening. Low pressure within the waste collection area directs fecal matter away from the user's buttocks and prevents the escape of undesirable gases. The user actuates a piston covered with an absorbent pad that sweeps through the waste collection area to collect fecal matter, scrub the waste collection area, press the matter against an end of the waste collection area and retracts, leaving the used pad. Multiple pads are provided on the piston to accommodate multiple uses of the system. Also a valve allows air to be drawn through the body, which valve will not be plugged with fecal matter. A sheet feeder feeds fresh sheets of absorbent pad to a face of the piston with each actuation

    Anthropometric changes and fluid shifts

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    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad

    Operant heart-rate conditioning in the curarised rat

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    Many two-process learning theorists have attempted to separate the processes of operant and classical conditioning on the basis that the type of response each governed was typically different. Specifically, it has been postulated that responses of the autonomic nervous system are not subject to the direct influence of operant contingencies. Within a bidirectional experimental design, it was shown that both increases and decreases in heart-rate could be produced by operant training procedures. The considerably easier task of shaping increases in rate was attributed to the interaction of the schedule and the unconditioned effects of the reinforcer on heart-rate. However, the results of the training procedures on the heart-rate were shown not to be a direct consequence of the presentations of the reinforcer. In these studies curarised animals were used in order to rule out the possibility that the heart-rate changes were mediated by operant manipulations of overt and covert skeletal responses. Caution was stressed in the use of curariform drugs in studies of autonomic conditioning both because of their possible blocking action on autonomic ganglia and because of the difficulty in applying adequate and consistent artificial ventilation to the animal. Experimental attempts were made to determine the specific mechanisms responsible for the operant heart-rate changes which were obtained. The evidence implied that increased output from both the sympathetic cardiac nerves and the adrenal medulla were responsible for maintaining the increases in heart-rate. This evidence, together with the results of an experiment which showed depletion in levels of adrenal adrenaline as a consequence of the baseline procedures of curarisation and artificial ventilation, suggested that the procedures involved in these studies were stressful to the animal, producing increased sympathetic functioning .The difficulty in resolving the problem of whether operant and classical conditioning are separate processes was not resolved by these experiments because of the possibility of central nervous system responses being influenced by each type of conditioning. The implications of these studies interpretation of autonomic response changes is considerable and the probable importance of operant components in studies of classical conditioning were elaborated

    Simulation synergy : expanding TRNSYS capabilities and usability

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    Developers of simulation packages are now able to take advantage of the increase in available desktop computing power to expand the capabilities and usability of their programs. This paper will illustrate these opportunities by discussing the different techniques the developers of the TRNSYS software package have used to try and create a synergy between TRNSYS and external programs and between the developers and users of the program

    Transport of sulfur dioxide from the Asian Pacific Rim to the North Pacific troposphere

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    The NASA Pacific Exploratory Mission over the Western Pacific Ocean (PEM-West B) field experiment provided an opportunity to study sulfur dioxide (SO2) in the troposphere over the western Pacific Ocean from the tropics to 60°N during February–March 1993. The large suite of chemical and physical measurements yielded a complex matrix in which to understand the distribution of sulfur dioxide over the western Pacific region. In contrast to the late summer period of Pacific Exploratory Mission-West A (PEM-West A) (1991) over this same area, SO2showed little increase with altitude, and concentrations were much lower in the free troposphere than during the PEM-West B period. Volcanic impacts on the upper troposphere were again found as a result of deep convection in the tropics. Extensive emission of SO2 from the Pacific Rim land masses were primarily observed in the lower well-mixed part of the boundary layer but also in the upper part of the boundary layer. Analyses of the SO2 data with aerosol sulfate, beryllium-7, and lead-210 indicated that SO2 contributed to half or more of the observed total oxidized sulfur (SO2 plus aerosol sulfate) in free tropospheric air. The combined data set suggests that SO2 above 8.5 km is transported from the surface but with aerosol sulfate being removed more effectively than SO2. Cloud processing and rain appeared to be responsible for lower SO2 levels between 3 and 8.5 km than above or below this region

    Book Reviews

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