Mechanical actuator Patent

Mechanical actuator wherein linear motion changes to rotational motio

A parametric study of effect of forebody shape on flow angularity at Mach 8

Flow angularity and static pressure measurements have been made on the lower surface of nine forebody models that simulate the bottom forward surface of a hypersonic aircraft. Measurements were made in an area of the forebody that represents the location of an inlet of a scramjet engine. A parametric variation of the forebody surface investigated the effect of: (1) spanwise curvature; (2) longitudinal curvature; and (3) planform shape on both flow angularity and static pressure distribution. Results of each of the three parametric variations of geometry were compared to those for the same flat delta forebody. Spanwise curvature results showed that a concave shape and the flat delta had the lowest flow angularity and lowest rate of increase in flow angularity with angle of attack. Longitudinal curvature results showed a convex surface to give the better flow at the higher angles of attack. The better of the two planform shapes tested was a convex elliptical shape. Limited flow field calculations were made at angles of attack using a three dimensional, method-of-characteristics program. In general, at all angles of attack there was agreement between data and theory

The reduced order model problem in distributed parameter systems adaptive identification and control

The basic assumption that a large space structure can be decoupled preceding the application of reduced order active control was considered and alternative solutions to the control of such structures (in contrast to the strict modal control) were investigated. The transfer function matrix from the actuators to the sensors was deemed to be a reasonable candidate. More refined models from multivariable systems theory were studied and recent results in the multivariable control field were compared with respect to theoretical deficiencies and likely problems in application to large space structures

Effects of Weightlessness on Human Fluid and Electrolyte Physiology

The changes that occur in human fluid and electrolyte physiology during the acute and adaptive phases of adaptation to spaceflight are summarized. A number of questions remain to be answered. At a time when plasma volume and extracellular fluid volume are contracted and salt and water intake is unrestricted. ADH does not correct the volume deficit and serum sodium decreases. Change in secretion or activity of a natriuretic factor during spaceflight is one possible explanation. Recent identification of a polypeptide hormone produced in cardiac muscle cells which is natiuretic, is hypotensive, and has an inhibitory effect on renin and aldosterone secretion has renewed interest in the role of a natriuretic factor. The role of this atrial natriuretic factor (ANF) in both long- and short-term variation in extracellular volumes and in the inability of the kidney to bring about an escape from the sodium-retaining state accompanying chronic cardiac dysfunction makes it reasonable to look for a role of ANF in the regulation of sodium during exposure to microgravity. Prostaglandin-E is another hormone that may antagonize the action of ADH. Assays of these hormones will be performed on samples from crew members in the future

Proton-radiation damage in Gunn oscillators

The irradiation effects of 22 MeV protons on the electrical characteristics of GaAs continuous-wave Gunn oscillators was studied. The radio frequency power output was reduced by 3 decibels at proton fluences in the neighborhood of 1.5 x 10 to the 12th power protons/sq cm. Conductance measurements indicate that the carrier removal rate at high electric fields remained roughly 40 percent less than at low fields. Diode efficiencies of two device groups were found to be monotonically descreasing functions of fluence. Frequency modulation noise was generally unaffected by radiation, but the magnitude of the noise in the noise power spectrum increased significantly. These effects are partially accounted for, in a qualitative fashion, by a model of electron traps having field-dependent net-carrier capture rates and various response times

Space Station medical sciences concepts

Current life sciences concepts relating to Space Station are presented including the following: research, extravehicular activity, biobehavioral considerations, medical care, maintenance of dental health, maintaining health through physical conditioning and countermeasures, protection from radiation, atmospheric contamination control, atmospheric composition, noise pollution, food supply and service, clothing and furnishings, and educational program possibilities. Information on the current status of Soviet Space Stations is contained

The reduced order model problem in distributed parameter systems adaptive identification and control

The reduced order model problem in distributed parameter systems adaptive identification and control is investigated. A comprehensive examination of real-time centralized adaptive control options for flexible spacecraft is provided