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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Recycling plant, human and animal wastes to plant nutrients in a closed ecological system

The essential minerals for plant growth are nitrogen, phosphorous, potassium (macronutrients), calcium, magnesium, sulfur (secondary nutrients), iron, manganese, boron, copper, zinc, chlorine, sodium, and molybdenum (micronutrients). The first step in recycling wastes will undoubtedly be oxidation of carbon and hydrogen to CO2 and H2O. Transformation of minerals to plant nutrients depends upon the mode of oxidation to define the state of the nutrients. For the purpose of illustrating the type of processing required, ash and off-gas compositions of an incineration process were assumed and subsequent processing requirements were identified. Several processing schemes are described for separating out sodium chloride from the ash, leading to reformulation of a nutrient solution which should be acceptable to plants.

Meissner, H. P.↗
NASA NTRS1981

Evaluation of engineered foods for Closed Ecological Life Support System (CELSS)

A system of conversion of locally regenerated raw materials and of resupplied freeze-dried foods and ingredients into acceptable, safe and nutritious engineered foods is proposed. The first phase of the proposed research has the following objectives: (1) evaluation of feasibility of developing acceptable and reliable engineered foods from a limited selection of plants, supplemented by microbially produced nutrients and a minimum of dehydrated nutrient sources (especially those of animal origin); (2) evaluation of research tasks and specifications of research projects to adapt present technology and food science to expected space conditions (in particular, problems arising from unusual gravity conditions, problems of limited size and the isolation of the food production system, and the opportunities of space conditions are considered); (3) development of scenarios of agricultural production of plant and microbial systems, including the specifications of processing wastes to be recycled.

Karel, M.↗
NASA NTRS1980

The carbon isotope biogeochemistry of the individual hydrocarbons in bat guano and the ecology of the insectivorous bats in the region of Carlsbad, New Mexico

The structures and C-13 contents of individual hydrocarbons extracted from bat guano found in the Carlsbad region of New Mexico are analyzed in order to elucidate details of the carbon flow in the plant-insect-bat ecosystem. Carbon isotopic analyses indicate that equivalent numbers of plants with C3 and C4 photosynthetic pathways occupy the feeding area of the bats, which supports alfalfa and cotton as well as native plants. The molecular composition of the guano is consistent with an origin in two distinct populations of insects with different feeding habits, one of which may graze predominantly on crops. It is also pointed out that isotopic analyses of more ancient guano deposits may be useful in characterizing prevalent vegetation and climate of earlier periods.

Des Marais, D. J.↗
NASA NTRS1981

Microbial ecology of extreme environments: Antarctic dry valley yeasts and growth in substrate limited habitats

The multiple stresses temperature, moisture, and for chemoheterotrophs, sources of carbon and energy of the Dry Valley Antarctica soils allow at best depauperate communities, low in species diversity and population density. The nature of community structure, the operation of biogeochemical cycles, the evolution and mechanisms of adaptation to this habitat are of interest in informing speculations upon life on other planets as well as in modeling the limits of gene life. Yeasts of the Cryptococcus vishniacil complex (Basidiobiastomycetes) are investigated, as the only known indigenes of the most hostile, lichen free, parts of the Dry Valleys. Methods were developed for isolating these yeasts (methods which do not exclude the recovery of other microbiota). The definition of the complex was refined and the importance of nitrogen sources was established as well as substrate competition in fitness to the Dry Valley habitats.

Vishniac, H. S.↗
NASA NTRS1982

Controlled ecological life support system - biological problems

The general processes and controls associated with two distinct experimental paradigms are examined. Specific areas for research related to biotic production (food production) and biotic decomposition (waste management) are explored. The workshop discussions were directed toward Elemental cycles and the biological factors that affect the transformations of nutrients into food, of food material into waste, and of waste into nutrients were discussed. To focus on biological issues, the discussion assumed that (1) food production would be by biological means (thus excluding chemical synthesis), (2) energy would not be a limiting factor, and (3) engineering capacity for composition and leak rate would be adequate.

Moore, B., III↗
NASA NTRS1981

Generic waste management requirements for a controlled ecological life support system /CELSS/

Regenerative life support systems for future space missions will require closure of the waste-food loop. Each mission application will generate specific requirements for the waste management system. However, there are generic input and output requirements that can be identified when a probable scenario is chosen. This paper discusses the generic requirements when higher plants are chosen as the primary food source. Attention is focused on the quality and quantity of nutrients necessary for culturing higher plants. The types of wastes to be processed are also discussed. In addition, requirements generated by growing plants on three different substrates are presented. This work suggests that the mineral composition of waste materials may require minimal adjustment to satisfy the plant requirements.

Hoshizaki, T.↗
NASA NTRS1982

Ecological optimality in water-limited natural soil-vegetation systems. II - Tests and applications

The long-term optimal climatic climax soil-vegetation system is defined for several climates according to previous hypotheses in terms of two free parameters, effective porosity and plant water use coefficient. The free parameters are chosen by matching the predicted and observed average annual water yield. The resulting climax soil and vegetation properties are tested by comparison with independent observations of canopy density and average annual surface runoff. The climax properties are shown also to satisfy a previous hypothesis for short-term optimization of canopy density and water use coefficient. Using these hypotheses, a relationship between average evapotranspiration and optimum vegetation canopy density is derived and is compared with additional field observations. An algorithm is suggested by which the climax soil and vegetation properties can be calculated given only the climate parameters and the soil effective porosity. Sensitivity of the climax properties to the effective porosity is explored.

Eagleson, P. S.↗
NASA NTRS1983

Planetary biology and microbial ecology. Biochemistry of carbon and early life

Experiments made with cyanobacteria, phototrophic bacteria, and methanogenic bacteria are detailed. Significant carbon isotope fractionation data is included. Taken from well documented extant microbial communities, this data provides a basis of comparison for isotope fractionation values measured in Archean and Proterozoic (preCambrian) rocks. Media, methods, and techniques used to acquire data are also described.

Margulis, L.↗
NASA NTRS1984

Algal culture studies related to a Closed Ecological Life Support System (CELSS)

In many respects, algae would be the ideal plant component for a biologically based controlled life support system, since they are eminently suited to the closely coupled functions of atmosphere regeneration and food production. Scenedesmus obliquus and Spirulina platensis were grown in three continuous culture apparatuses. Culture vessels their operation and relative merits are described. Both light and nitrogen utilization efficiency are examined. Long term culture issues are detailed and a discussion of a plasmid search in Spirulina is included.

Radmer, R.↗
NASA NTRS1983

Control and modeling of a CELSS (Controlled Ecological Life Support System)

Research topics that arise from the conceptualization of control for closed life support systems which are life support systems in which all or most of the mass is recycled are discussed. Modeling and control of uncertain and poorly defined systems, resource allocation in closed life support systems, and control structures or systems with delay and closure are emphasized.

Auslander, D. M.↗
NASA NTRS1985

Controlled Ecological Life Support Systems (CELSS)

One of the major problems facing researchers in the design of a life support system is to construct it so that it will be capable of regulating waste materials and gases, while at the same time supporting the inhabitants with adequate food and oxygen. The basis of any gaseous life supporting cycle is autotrophs (plants that photosynthesize). The major problem is to get the respiratory quotient (RQ) of the animals to be equivalent to the assimilatory quotient (AQ) of the plants. A technique is being developed to control the gas exchange. The goal is to determine the feasibility of manipulating the plant's AQ by altering the plants environment in order to eliminate the mismatch between the plant's AQ and the animal's RQ.

Majumdar, M.↗
NASA NTRS1984

Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

An extreme environment is by definition one with a depauperate biota. While the Ross Desert is by no means homogeneous, the most exposed and arid habitats, soils in the unglaciated high valleys, do indeed contain a very sparse biota of low diversity. So sparse that the natives could easily be outnumbered by airborne exogenous microbes. Native biota must be capable of overwintering as well as growing in the high valley summer. Tourists may undergo a few divisions before contributing their enzymes and, ultimately, elements to the soil - or may die before landing. The simplest way to demonstrate the indigenicity of a particular microbe is therefore to establish unique distribution; occurrence only in the habitat in question precludes foreign origin.

Vishniac, H. S.↗