Fluctuations and Relationships of Selected Physiochemical Parameters in Dardanelle Reservoir, Arkansas, 1975-1982

Annual and seasonal fluctuations and relationships are described for discharge, turbidity, chloride, total hardness, conductivity and suspended solids over an eight-year period in Dardanelle Reservoir. The parameters fluctuated rather widely primarily in response to seasonal patterns of rainfall. Chloride and conductivity were related and generally fluctuated together as did turbidity and suspended solids. Hardness appeared to vary independently of the others prior to 1979 then varied more closely with chloride after March 1979. Inherent differences between the Illinois Bayou arm and the main Arkansas River sections complicated the precise identification of any overall impact of power plant operation. No significant long term changes were seen, but chloride declined gradually whereas hardness and conductivity increased slightly. Suspended solids exhibited a significant rise in 1982

Phytoplankton Community Structure in Dardanelle Reservoir, Arkansas, 1975-1982

Phytoplankton data were collected with standard equipment and procedures over an eight-year period (1975-1982) in Dardanelle Reservoir, Arkansas. Community abundance and diversity at the genus level are described. Sixty-five genera representing 35 families and five divisions were identified. Total phytoplankton abundance and diversity were quite uniform among the stations but fluctuated considerably with time. These fluctuations did not correspond clearly with season. Dominant taxa were seasonal, though, with diatoms being usually dominant in January, April and October, and blue-greens dominant in July. The phytoplankton community structure has not been significantly altered by the operation of ANO Unit I

The undersea habitat as a space station analog: Evaluation of research and training potential

An evaluation is given of the utility of undersea habitats for both research and training on behavioral issues relative to the space station. The feasibility of a particular habitat, La Chalupa, is discussed

Power requirements for the first lunar outpost (FLO)

NASA's Exploration Program Office is currently developing a preliminary reference mission description that lays the framework from which the nation can return to the Moon by the end of the decade. The First Lunar Outpost is the initial phase of establishing a permanent presence on the Moon and the next step of sending humans to Mars. Many systems required for missions to Mars will be verified on the Moon, while still accomplishing valuable lunar science and in-situ resource utilization (ISRU). Some of FLO's major accomplishments will be long duration habitation, extended surface roving (both piloted and teleoperated) and a suite of science experiments, including lunar resources extraction. Of equal challenge will be to provide long life, reliable power sources to meet the needs of a lunar mission

Human performance in aerospace environments: The search for psychological determinants

A program of research into the psychological determinants of individual and crew performance in aerospace environments is described. Constellations of personality factors influencing behavior in demanding environments are discussed. Relationships between attitudes and performance and attitudes and personality are also reported. The efficacy of training in interpersonal relations as a means of changing attitudes and behavior is explored along with the influence of personality on attitude change processes. Finally, approaches to measuring group behavior in aerospace settings are described

Rapid induction bonding of composites, plastics, and metals

The Toroid Bonding Gun is and induction heating device. It is a self contained, portable, low powered induction welding system developed for bonding or joining plastic, ceramic, or metallic parts. Structures can be bonded in a factory or in a the field. This type of equipment allows for applying heat directly to the bond lines and/or to the adhesives without heating the entire structure, supports, and fixtures of a bonding assembly. The induction heating gun originally developed for use in the fabrication of space Gangs of bonders are now used to rapidly join composite sheet and structural components. Other NASA-developed applications of this bonding technique include the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials

Ceramic susceptor for induction bonding of metals, ceramics, and plastics

A thin (.005) flexible ceramic susceptor (carbon) was discovered. It was developed to join ceramics, plastics, metals, and combinations of these materials using a unique induction heating process. Bonding times for laboratory specimens comparing state of the art technology to induction bonding were cut by a factor of 10 to 100 times. This novel type of carbon susceptor allows for applying heat directly and only to the bondline without heating the entire structure, supports, and fixtures of a bonding assembly. The ceramic (carbon film) susceptor produces molten adhesive or matrix material at the bond interface. This molten material flows through the perforated susceptor producing a fusion between the two parts to be joined, which in many instances has proven to be stronger than the parent material. Bonding can be accomplished in 2 minutes on areas submitted to the inductive heating. Because a carbon susceptor is used in bonding carbon fiber reinforced plastics and ceramics, there is no radar signature or return making it an ideal process for joining advanced aerospace composite structures

Method of Attaching Strain Gauges to Various Materials

A method is provided to bond strain gauges to various materials. First, a tape with an adhesive backing is placed across the inside of the fixture frame. The strain gauge is flatly placed against the adhesive backing and coated with a thin, uniform layer of adhesive. The tape is then removed from the fixture frame and placed, strain gauge side down, on the material to be tested. If the material is a high reluctance material, the induction heating source is placed on the tape. If the material is a low reluctance material, a plate with a ferric side and a rubber side is placed, ferric side down, onto the tape. The induction heating source is then placed upon the rubber side. If the material is an insulator material, a ferric plate is placed on the tape. The induction heating source is then placed on the ferric plate. The inductive heating source then generates frequenty from 60 to 70 kilocycles to inductively heat either low reluctance material, ferric side, of ferric plate and provides incidental pressure of approximately five pounds per square inch to the tape for two minutes, thoroughly curing the adhesive. The induction heating source, and, if necessary, the plate or ferric plate, are then removed from the tape after one minute. The tape is then removed from the bonded strain gauge

Ameiva leberi

Number of Pages: 2Integrative BiologyGeological Science