On the design of an adjustable high precision latching hinge

The design and test details of a high precision hinge and locking mechanism created principally in support of the Lockheed space deployable Flexrib Parabolic Antenna concept are presented. These developed improvements in the detail design of ultra-precise rib hinge and contour adjustment mechanisms will allow radio frequency antenna reflectors to expand into the 15-50 meter diameter size class and to support the .013 mm. deployment repeatability tolerance required to support the 12+ GHz frequency range

Effects of a simulated space environment on thermal radiation characteristics of selected black coatings

Simulated space environment effects on thermal radiation characteristics of black coating

Vacuum and ultraviolet radiation effects on binders and pigments for spacecraft thermal control coatings

An evaluation of several silicone resin binders and powdered inorganic pigments for potential use in spacecraft thermal-control paint formulations is presented. The pigments were selected on the basis of a hypothesis relating the heat of formation of a compound to the compound's resistance to ultra-radiation-induced degradation. Reflectance measurements were made in situ to determine degradation rates due to ultraviolet radiation. The tested polydimethylsiloxane resins were not significantly affected by long exposures to ultraviolet radiation. All the pigments, which were dispersed in a polydimethylsiloxane resin, were degraded by ultraviolet radiation as determined by an increase of solar absorptance. For the materials evaluated in this study, no evidence was found to indicate that pigments with high heats of formation were resistant to ultraviolet degradation

Study of wrap-rib antenna design

The results of a parametric design study conducted to develop the significant characteristics and technology limitations of space deployable antenna systems with aperture sizes ranging from 50 up to 300 m and F/D ratios between 0.5 and 3.0 are presented. Wrap/rib type reflectors of both the prime and offset fed geometry and associated feed support structures were considered. The significant constraints investigated as limitations on achievable aperture were inherent manufacturability, orbit dynamic and thermal stability, antenna weight, and antenna stowed volume. A data base, resulting in the defined maximum achievable aperture size as a function of diameter, frequency and estimated cost, was formed

Should Grain Elevator Managers Adopt Integrated Pest Management?

Insect infestation during storage and processing causes millions of dollars of wheat damage annually in the United States. Insect infestation reduces wheat storing processing profit as well as consumer confidence in wheat food products. Meanwhile, increased concerns about insecticide use have increase interest in Integrated Pest Management (IPM) strategies. This research compares the costs of IPM and chemical-based approaches to insect control to determine why most elevator managers have not adopted IPM practices.Agribusiness,

Binary Communication Systems Using Wideband Signals (Final Report v.II)

It has been pointed out that communication systems having wideband signal waveforms have certain advantages over the conventional narrowband systems. This report describes the results of a research program which examined in detail the information efficiency of wideband systems. The results presented in this report fall into three major categories: (1) analysis of systems utilizing linear receivers (i.e. synchronous receivers , etc.), (2) analysis of system utilizing non-linear receivers, and (3) analysis and description of methods which can be used for realizing certain optimum and sub-optimum wideband receivers. The development of these topics is based on the geometrical concept of a signal space. These signal space concepts along with certain definitions are discussed in Chapter II. In Chapters III, IV and V wideband systems utilizing linear receivers are analyzed and the performance of these systems is determined for certain important types of noise which may be added in this communication channel. It is shown that in most cases, optimum performance cannot be obtained through the use of linear receivers. Non-linear techniques which are capable of supplying improved performance are discussed in detail in Chapters VI and VII. From the consideration of the types of noise which one may expect to encounter when using wideband systems, it is apparent that a relatively sophisticated approach is required in order to obtain the required physical realizations„ Certain methods which appear to be useful in obtaining these realizations are discussed in Chapter VIII and IX. Because the nature of the interference, in general, will not be known in detail to the designer, certain adaptive techniques are incorporated

A Computerized Mapping System for Forest Resource Management Planning

Large volumes of inventory data are collected and analyzed with the idea of developing resource management schemes for the future. Unless this inventory information is easily accessible, is of the type needed to make management decisions in accordance with current policy, and has a readily available updating system, the entire management plan often becomes a seldom, if ever, used document. This study deals with the application of several inventory collection and display techniques to assist in making rapid and accurate resource management decisions on a continuing basis. The objective of the study is to develop a comprehensive forest resource management plan for the U.S. Department of the Army, Corps of Engineers Philpott Reservoir Complex located on the Piedmont geomorphic province near Bassett, Virginia. Specifically the management plan is focused on increasing the value of the lands primarily for recreation and wildlife with the inclusion of other compatible uses where appropriate. A healthy and vigorous forest system is required in order to withstand the stresses imposed by man and nature. Therefore, a forest complex capable of supporting the planned recreation, wildlife, scenic attractiveness and other project uses must be maintained so as to yield the maximum social benefit and insure the ecologic integrity of the system