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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4

Aerospace manpower transfer to small business enterprises

The feasibility of a program to effect transfer of aerospace professional people from the ranks of the unemployed into gainful employment in the small business community was investigated. The effectiveness of accomplishing transfer of technology from the aerospace effort into the private sector through migration of people rather than products or hardware alone was also studied. Two basic methodologies were developed. One involves the matching of ex-aerospace professionals and small companies according to their mutual needs. A training and indoctrination program is aimed at familiarizing the professional with the small company environment, and a program of follow-up counseling is defined. The second methodology incorporates efforts to inform and arouse interest among the nonaerospace business community toward affirmative action programs that will serve mutual self-interests of the individuals, companies, and communities involved.

Green, M. K.↗

Electrophysiological studies of the nervous system

The electrophysiology of the nervous system is studied using cats and human subjects. Data cover effects of chlorolose on evoked potential, the evoked resistance shift that accompanies evoked potentials, and the relationship of eye movements to potentials aroused by visual stimulation.

Galambos, R.↗

A Multidisciplinary Survey for the Management of Alaskan Resources Utilizing ERTS Imagery

The application of ERTS-1 imagery for a multidisciplinary study of Alaskan resources is discussed. ERTS-1 data form a politically neutral base from which resource surveys can be made without arousing suspicions from groups which have mutually confliciting goals. The specific use of ERTS-1 imagery for monitoring migratory animals, pipeline locations, road construction, snow cover, and vegetation growth is reported. Maps, illustrations, and photographs are provided to support the data.

Miller, J. M.↗

Emotional state and efficiency

An investigation was made of the effect of emotional states-negative and positive- on work performance. Data cover intensity of emotional arousal, personality characteristics of person involved, typological features of person's nervous system, emotional stability of person, and past experience of person. Particular attention was given to emotional stress effects on efficiency, given modern working conditions.

Ovchinnikova, O. V.↗

Effects of aircraft noise on human sleep.

Under controlled conditions in two test rooms, studies were made of the response of sleeping subjects to the stimuli of simulated sonic booms and subsonic jet aircraft noise. Children were relatively nonresponsive to the stimuli. In general, the older the subject, the more likely is behavioral awakening. The response rates to the two types of stimuli were essentially the same. The stimulus intensity had little, if any, effect on frequency of arousal, although other degrees of response did increase.

Lukas, J. S.↗

A theory of microwave apparent temperature over the ocean

In the microwave region combined active (scatterometer) and passive (radiometer) remote sensors over the ocean show promise of providing surface wind speeds and weather information to the oceanographer and meteorologist. This has aroused great interest in the investigation of the scattering of waves from the sea surface. A composite surface scattering theory is investigated. The two-scale scattering theory proposed by Semyonov was specifically extended to compute the emmision and scattering characteristics of ocean surfaces. The effects of clouds and rain on the radiometer and scatterometer observations are also investigated using horizontally stratified model atmospheres with rough sea surfaces underneath. Various cloud and rain models proposed by meteorologist were employed to determine the rise in the microwave temperature when viewing downward through these model atmospheres. For heavy rain-fall rates the effects of scattering on the radiative transfer process are included.

Wu, S. T.↗

Habituation of vestibular responses: An overview

An historical survey of vestibular habituation experiments has been undertaken. Methodological problems are presented briefly, and the influence of arousal on vestibular responses is detailed. Data obtained from animals and from man are treated separately. At least for man, the term habituation may be better defined by a dynamic change in the form of vestibular responses than by a simple response reduction.

Collins, W. E.↗

Effects of noise upon human information processing

Studies of noise effects upon human information processing are described which investigated whether or not effects of noise upon performance are dependent upon specific characteristics of noise stimulation and their interaction with task conditions. The difficulty of predicting noise effects was emphasized. Arousal theory was considered to have explanatory value in interpreting the findings of all the studies. Performance under noise was found to involve a psychophysiological cost, measured by vasoconstriction response, with the degree of response cost being related to scores on a noise annoyance sensitivity scale. Noise sensitive subjects showed a greater autonomic response under noise stimulation.

Cohen, H. H.↗

Noise and sleep - A literature review and a proposed criterion for assessing effect

Results of a number of studies on the effects of various types of noise on the sleep of subjects of both sexes and a wide range of age groups are reviewed to develop a tentative criterion for assessing these effects. Available data suggest that reasonably accurate predictions of sleep disruption may be made if the interfering noise is specified in units (EPNdB or EdBA) which account for its spectral characteristics and duration. When EPNdB units are used as the measure of noise intensity, the correlation coefficient between intensity and the probability of no sleep disturbance is -0.86. Because of the paucity of data on the long-term results of frequent behavioral wakings or arousals, it is suggested that disturbance of sleep be defined as an electroencephalographic change of one or more sleep stages.

Lukas, J. S.↗

Coma recovery

Arousal from coma is defined as a function of the reticular activating system that is located between the spinal cord and the diencephalon core of the brain stem. This system receives information from all the sensory functions of the body for distribution to the various parts of the cortex in order to maintain normal activities. Multimodal, neurosensory stimulation techniques are outlined that are designed to help the patient recover from the comatose state.

Dimancescu, M. D.↗

The visual accommodation response during concurrent mental activity

The direction and magnitude of the human visual accommodation response during concurrent mental activity are investigated. Subject focusing responses to targets at distances of 0.0 D, 3.0 D and an indeterminate distance were monitored by means of an optometer during the performance of a backwards counting task and a visual imagery task (thinking near and thinking far). In both experiments a shift in accommodation towards the visual far point is observed particularly for the near target, which increases with the duration of the task. The results can be interpreted in terms of both the capacity model of Kahneman (1973) and the autonomic arousal model of Hess and Polt (1964), and are not inconsistent with the possibility of an intermediate resting position.

Malmstrom, F. V.↗

Physiological correlates of mental workload

A literature review was conducted to assess the basis of and techniques for physiological assessment of mental workload. The study findings reviewed had shortcomings involving one or more of the following basic problems: (1) physiologic arousal can be easily driven by nonworkload factors, confounding any proposed metric; (2) the profound absence of underlying physiologic models has promulgated a multiplicity of seemingly arbitrary signal processing techniques; (3) the unspecified multidimensional nature of physiological "state" has given rise to a broad spectrum of competing noncommensurate metrics; and (4) the lack of an adequate definition of workload compels physiologic correlations to suffer either from the vagueness of implicit workload measures or from the variance of explicit subjective assessments. Using specific studies as examples, two basic signal processing/data reduction techniques in current use, time and ensemble averaging are discussed.

Zacharias, G. L.↗

Introduction: Historical perspective on the HCMM program

When some thermal radiation sensitive devices on U.S. meteorological satellites generated low resolution images showing temperature variations on Earth's land and sea surfaces during the middle 1960's, interest was aroused in the potential of thermal sensing in geology, agriculture, soil moisture, ground water, water temperature, and vegetation applications. The concept of using the property of thermal inertia to identify materials, particularly those of a geologic nature can be traced to the same time period that marks the flight of the first LANDSAT - Spacecraft systems and their performance, and capabilities are reviewed as well as achievements in hydrology, geology, agriculture, pedology, and urban climate effects applications.

Source record↗

Visceral predictors of cardiovascular deconditioning in late middle-aged men

A number of visceral and behavioral factors connected with cardiovascular deconditioning were investigated, in order to identify a method for predicting the degree of orthostatic intolerance to spaceflight in several late-middle-aged men (55-65 years). Preliminary measurements were made of: mean arterial blood pressure plasma cortisol levels; and norepinephrine levels. Measurements of core temperature; plasma epinephrine level and subjective arousal from sleep were also obtained. Pairwise correlations were found for each of the variables and the time-to-blackout due centrifugal acceleration of up to +3 Gz. It is shown that the men with relatively low resting blood pressure were at greater risk of developing the clinical signs of cardiovascular deconditioning than were the men with higher basal blood pressure. Some applications of the experimental results to the development of selection criteria for Shuttle crews are discussed.

Goldwater, D. J.↗

The effects of stress on attentional resources

A new perspective is presented from which to view the action of stress on human behavior. At a behavioral level, the action of stress is related to notions of human attention and an indication of an isomorphic relationship between modes of control at a physiological and behavioral level is presented. Examples of this phenomenon are extracted from performance under heat stress, since this is one of the most simple stress circumstances. It is suggested that stress sufficient to overcome adaptive capability, that is efficient homeostasis, acts to drain attentional resources. The manner in which such resources fail approximates that function typical of a positive feedback system, which also characterizes the breakdown of physiological response under severe environmental stress. The end point of this draining sequence is the absence of all attentional resources, which is taken to be unconsciousness, to be rapidly followed by the failure of physiological adaptability upon which life sustaining functions depend. This overall picture preserves the inverted-U shaped relationship between stress and performance, yet is in distinct contrast to the traditional arousal account of such behavior. The theoretical and practical ramifications of these observations are explored.

Hancock, P. A.↗

Workload - An examination of the concept

The relations between task difficulty and workload and workload and performance are examined. The architecture and limitations of the central processor are discussed. Various procedures for measuring workload are described and evaluated. Consideration is given to normative and descriptive approaches; subjective, performance, and arousal measures; performance operating characteristics; and psychophysiological measures of workload.

Gopher, Daniel↗

Mode 2 fracture mechanics

Current development of high-performance rolling element bearings for aircraft engines (up to 3 million DN, where DN is the product of shaft diameter in millimeters and speed in revolutions per minute) has aroused concern about fatigue crack growth in the inner bearing race that leads to catastrophic failure of the bearing and the engine. A failure sequence was postulated by Srawley, and an analytical program was undertaken to simulate fatigue crack propagation in the inner raceway of such a bearing. A fatigue specimen was developed at NASA by which fatigue data may be obtained relative to the cracking problems. The specimen may be used to obtain either mode 2 data alone or a combination of mixed-mode (1 and 2) data as well and was calibrated in this regard. Mixed-mode fracture data for M-50 bearing steel are presented, and a method for performing reversed-loading tests is described.

Buzzard, Robert J.↗

Pupil measures of alertness and mental load

A study of eight adults given active and passive search tasks showed that evoked pupillary response was sensitive to information processing demands. In particular, large pupillary diameter was observed in the active search condition where subjects were actively processing information relevant to task performance, as opposed to the passive search (control) condition where subjects passively viewed the displays. However, subjects may have simply been more aroused in the active search task. Of greater importance was that larger pupillary diameter, corresponding to longer search time, was observed for noncoded than for color-coded displays in active search. In the control condition, pupil diameter was larger with the color displays. The data indicate potential usefulness of pupillary responses in evaluating the information processing requirements of visual displays.

Backs, Richard W.↗