Driving and latching of the Starlab pointing mirror doors

The Starlab Experiment, a major SDIO technology initiative, is an attached payload which will be delivered into Earth orbit aboard NASA's Space Shuttle in 1991. Starlab will generate and aim an 80 cm diameter laser beam into space through a large opening in the structure which houses the pointing mirror. Two doors, each somewhat larger than a desktop, cover the opening when the laser optics system is nonoperational. Latch Mechanism Assemblies hold the doors shut during liftoff and ascent and, again, during Orbiter reentry. Each door is powered by a Door Drive System during the many open/close cycles between various experiments. The design, testing, and resultant failure modes of these mechanisms are examined

Multi Institutional Semi-Structured Learning Environments

A description of two effective and novel collaborative learning environments that support engineering and technological innovation is provided. While offering great value to systems, and systems of systems, engineering practice, these environments are not adequately described by either of these perspectives. Instead these multiinstitutional semi-structured learning environments are best described using an informing sciences perspective. Evidence is presented that these environments not only fulfill the definition of an informing system but may represent two of the more complete and dynamic instances of such systems with each simultaneously informing practice, research and teaching in a substantive manner that also produces engineering and technological innovation. The potential for these environments to serve as laboratories for both traditional and participatory research for those studying informing systems is suggested

Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch

The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch

THE DEMAND FOR MEAT PRODUCTS IN THE UNITED STATES: AN EMPIRICAL ANALYSIS

Given the importance of meat consumption, and the proportion of consumers' income spent on meat, this study estimates the demand for eight meat categories using two different functional forms. An inverse almost ideal demand system (IAIDS), and linear double-log price dependent demand models are specified. In most cases, flexibilities obtained from both methods are comparable and show that the demand for meat products is price inflexible. In addition, there are regional as well as seasonal variations in the demand for meat products.Demand and Price Analysis,

Fractionation of human immune γ-globulin

Equine and bovine serum proteins have recently been fractionated by means of a physical method utilizing an electrophoretic adaptation of the principles of the Clusius column (l-4), first described and tested by Kirkwood (5) and Nielsen (6). The method of electrophoresis-convection has now been applied to the fractionation of human γ-globulin. The γ-globulin was prepared by ethanol fractionation (7) from the plasma of individuals hyperimmunized to Hemophilus pertussis organisms. The resulting fractions of γ-globulin have been characterized electrophoretically, and the protective antibody activity and agglutinin titer have been measured

PRODUCT CHARACTERISTICS AFFECTING CONSUMERS' FRESH BEEF CUT PURCHASING DECISIONS IN THE UNITED STATES, JAPAN, AND AUSTRALIA

The effects of product and economic characteristics on consumers who purchase six cuts of fresh beef (blocks/parts, steak, thinly sliced, diced, chopped, and ground) in urban areas of the United States, Japan, and Australia will be examined in this paper. Certain product characteristics (such as product freshness and display case cleanliness) were important to consumers of beef in all three countries while other product characteristics (such as price considerations for ground beef consumers) were important for consumers of different beef cuts in all three countries. Some product characteristics varied in importance across consumers from different countries and consumers of different beef cuts.Consumer/Household Economics,

An Experiment In Collaborative Spreadsheet Development

To study the extent to which group development can reduce spreadsheet errors, an experiment compared error rates in spreadsheet development by subjects working alone (monads) and by subjects working in groups of three (triads). Impressively, triads made 78% fewer errors than monads. However, this was not as large a reduction as nominal group analysis suggests was possible. Members of triads were satisfied with group development. However, triads whose work went most smoothly, whose members were most satisfied with group interactions, and that had the loosest leadership structure were significantly more likely to make errors than other triads

Multinational Activity in the Modern World

Multinational corporations are the global goliaths of modern times. These entities collectively are responsible for large portions of world production, employment, investment, international trade, research, and innovation. Although their economic impact is most pronounced in high-income countries, where their activities have been concentrated historically, their reach increasingly extends to every corner of the world. Decisions made by these firms affect not only those who work for them, buy from them, do business with them, and compete with them, but also communities and countries in which they are located. As a result, their operations and activities are subjects of considerable interest and heated speculation

Effects of acute and chronic hypohydration on tolerance to plus Gz acceleration in man. I - Physiological results

Effects of acute and chronic hypohydration on human physiological tolerance to gravity acceleratio