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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Forecast of the general aviation air traffic control environment for the 1980's

The critical information required for the design of a reliable, low cost, advanced avionics system which would enhance the safety and utility of general aviation is stipulated. Sufficient data is accumulated upon which industry can base the design of a reasonably priced system having the capability required by general aviation in and beyond the 1980's. The key features of the Air Traffic Control (ATC) system are: a discrete address beacon system, a separation assurance system, area navigation, a microwave landing system, upgraded ATC automation, airport surface traffic control, a wake vortex avoidance system, flight service stations, and aeronautical satellites. The critical parameters that are necessary for component design are identified. The four primary functions of ATC (control, surveillance, navigation, and communication) and their impact on the onboard avionics system design are assessed.

Hoffman, W. C.↗
NASA NTRS1967

The Effects of Controlled Environment on the Growth of Hydrogenomonas Bacteria in Continuous Cultures

The continuous culture of Hydrogenomonas is the intermediate step of a three-step closed life support cycle directed to the conversion of the human metabolic wastes, urea and carbon dioxide, into breathable oxygen and a food supplement. The potential advantages of this scheme have been discussed in an earlier paper. The other two steps of the complete cycle are: (1) The collection and recovery of the C02 removed from the cabin atmosphere by a regenerable C02 absorber, so that relatively pure C02 gas can be fed into the gas phase of the continuous culture; and (2) the electrolysis of water to produce breathable oxygen for the cabin supply, and by-product hydrogen, which is also fed to the gas phase of the closed culture vessel. There are three specific advantages in the use of this culture: (1) the bacteria use waste urea as a sole nitrogen source during growth, together with the C02 waste as a carbon source; the harvested excess of cells from a steady-state culture is a potential food for man; (2) the organism is not photosynthetic, so the equipment designer need not confine the culture in thin layers to have light available to all parts as is necessary in photosynthesis; and (3) the culture uses the by-product hydrogen from electrolysis as an energy source. Some oxygen must also be supplied to the culture environment, because the energy of the growth process is derived from the metabolic hydrogen-oxygen reaction, with the production of water that can be recycled to the electrolysis cell.

ENVIRONMENTAL CONTROL↗
NASA NTRS1998

A Data Base of Nutrient Use, Water Use, CO2 Exchange, and Ethylene Production by Soybeans in a Controlled Environment

A data set is given describing daily nutrient and water uptake, carbon dioxide (CO2) exchange, ethylene production, and carbon and nutrient partitioning from a 20 sq m stand of soybeans (Glycine max (L.) Merr. cv. McCall] for use in bioregenerative life support systems. Stand CO2 exchange rates were determined from nocturnal increases in CO2 (respiration) and morning drawdowns (net photosynthesis) to a set point of 1000 micromol/ mol each day (i.e., a closed system approach). Atmospheric samples were analyzed throughout growth for ethylene using gas chromatography with photoionization detection (GC/PH)). Water use was monitored by condensate production from the humidity control system, as well as water uptake from the nutrient solution reservoirs each day. Nutrient uptake data were determined from daily additions of stock solution and acid to maintain an EC of 0.12 S/m and pH of 5.8. Dry mass yields of seeds, pods (without seeds), leaves, stems, and roots are provided, as well as elemental and proximate nutritional compositions of the tissues. A methods section is included to qualify any assumptions that might be required for the use of the data in plant growth models, along with a daily event calendar documenting set point adjustments and the occasional equipment or sensor failure.

Wheeler, R. M.↗
NASA NTRS1985

Controlled environment life support system: Calcium-related leaf injuries on plants

A calcium related injury in lettuce termed tipburn was the focus of this study. It affects the young developing leaves as they become enclosed during head formation. It is a good model system to study because the injury can be induced with good predictability and lettuce is one of the crops chosen by the CELSS program for concentrated study. Investigations were undertaken to study a number of different procedures, that would have the potential for encouraging movement of calcium into the young developing leaves and to study the time course and pattern of calcium accumulation in developing leaves to provide a basis for developing effective control procedures for this injury.

Tibbitts, T. W.↗
NASA NTRS1992

Generating the complete control environment interface for EASIE

The Environment for Application Software Integration and Execution (EASIE) was designed to meet the needs of conceptual design engineers that face the task of integrating the results of many stand alone engineering analysis programs. EASIE is a set of utility programs which supports rapid integration and execution of programs about a central relational database, and it provides users with two basic modes of executing operations: Application Derived Executive (ADE), a menu-driven execution mode which provides users with sufficient guidance to quickly review data, select menu action items, and execute application programs, and Complete Control Executive (CCE), which provides a full executive interface, allowing users in-depth control of the design process. Users can switch between these modes as needed. This project will consider the CCE mode interface. Two objectives of this project are to redesign the selecting menus by using a windowing system and to reorganize the selecting structures of the selecting menus. The project will be implemented in the C window system, OSF/Motif version.

Tsai, Chia-Lin↗
NASA NTRS2011

Allocation of Functions in a Far-Term Air Traffic Control Environment

A human-in-the-loop exploration of a ground-based automated separation assurance concept was conducted that involved the allocation of certain functions between humans and automation. This exploration included operations that were sustained for prolonged periods of time with high levels of traffic in the presence of convective weather and scheduling constraints. An investigation into the acceptability of the defined roles and performance of tasks was conducted where it was found that the participants rated the concept and allocation of functions with a high level of acceptability. However, issues were encountered with the automation related to the detection of and response to tactical conflicts. Lower ratings were given on account of these concerns, and it was found that a key contributor to the underlying problems was transitioning aircraft and the uncertainty of their trajectories. Stemming from those results, participants responded that they would rather have direct control over aircraft transitions as well as more control over the tactical conflict resolution automation. In contrast, participants responded that they would rather have the automation place aircraft back on trajectory, and perform weather avoidance and scheduling tasks.

Homola, Jeffrey↗
NASA NTRS1966

Portable lightweight cell provides controlled environment

Inflatable, lightweight cell provides a separate, secondary environment for a spacesuited man in case of spacesuit damage or malfunction. The cell has a pressure-sealing zipper and is equipped to maintain a livable atmosphere.

Shelton, S.↗
NASA NTRS1971

A study of phycophysiology in controlled environments

The primary objective of this research is to obtain fundamental data concerning the growth and metabolism of the unicellular green algae. These organisms are most likely to provide biological oxygen and a food source for space crews. Biochemical conversions, chemical composition, and cell growth and division are discussed. Chlorella sorokiniana is emphasized.

Krauss, R. W.↗
NASA NTRS1973

Operating Room Environment Control. Part A: a Valve Cannister System for Anesthetic Gas Adsorption. Part B: a State-of-the-art Survey of Laminar Flow Operating Rooms. Part C: Three Laminar Flow Experiments

An anesthetic gas flow pop-off valve canister is described that is airtight and permits the patient to breath freely. Once its release mechanism is activated, the exhaust gases are collected at a hose adapter and passed through activated coal for adsorption. A survey of laminar air flow clean rooms is presented and the installation of laminar cross flow air systems in operating rooms is recommended. Laminar flow ventilation experiments determine drying period evaporation rates for chicken intestines, sponges, and sections of pig stomach.

Meyer, J. S.↗