Engineering topics

Bubenheim, David L.

Publications and source records attributed to Bubenheim, David L..

36 records · Page 2

NASA NTRS1996

Significance of Plant Root Microorganisms in Reclaiming Water in CELSS

Since many microorganisms demonstrate the ability to quickly break down complex mixtures of waste and environmental contaminants, examining their potential use for water recycling in a closed environment is appealing. Water contributes approximately 90 percent of the life sustaining provisions in a human space habitat. Nearly half of the daily water requirements will be used for personal hygiene and dish washing. The primary contaminants of the used "gray" water will be the cleansing agents or soaps used to carry out these functions. Reclaiming water from the gray water waste streams is one goal of the NASA program, Controlled Ecological Life Support Systems (CELSS). The microorganisms of plane roots are well documented to be of a beneficial effect to promote plant growth. Most plants exhibit a range of bacteria and fungi which can be highly plant-specific. In our investigations with lettuce grown in hydroponic culture, we identified a microflora of normal rhizosphere. When the roots were exposed to an anionic surfactant, the species diversity changed, based on morphological characteristics, with the numbers of species being reduced from 7 to 2 after 48 hours of exposure. In addition, the species that became dominant in the presence of the anionic surfactant also demonstrated a dramatic increase in population density which corresponded to the degradation of the surfactant in the root zone. The potential for using these or other rhizosphere bacteria as a primary or secondary waste processor is promising, but a number of issues still warrant investigation; these include but are not limited to: (1) the full identification of the microbes, (2) the classes of surfactants the microbes will degrade, (3) the environmental conditions required for optimal processing efficiency and (4) the ability of transferring the microbes to a non-living solid matrix such as a bioreactor.

Bubenheim, David L.↗

NASA NTRS1996

A Hydrodynamic Model of Transport in the Wheat Ear

The vascular arrangement in the main axis (rachis) of the wheat ear, studied and reported in a previous paper by the same, described a circuit-cascade system consisting of capacitance and resistance passages (so-called RC-circuits). Some hydromechanic aspects (e.g., resonance, impulse control) of this asymmetric transport system and their possible role and importance in the fluid supply are discussed. A theoretical analysis of how this system works, as well as samples of practical application are presented.

Stieber, Joseph↗

NASA NTRS1996

The Main Transport System in the Wheat Ear

The vascular system in the rachis, rachilla, and florets of the wheat ear was studied by direct microscopical observation of cleaned semi longitudinal sections. A periodic repetitive change of amphivasal and collateral phases was found along each main vascular bundle in the rachis. This change alternates between the two groups of main bundles and is related to the bilateral alternate arrangement of the spikelets on the rachis, so that a large amphivasal phase of the one group opposes the collateral phase of the other group. Ring-shaped tracheary inter-connections were observed mostly at the nodes. A similar system was found in the rachilla. There is a continuous uninterrupted tracheary connection between each of the florets and the rachis. A functional significance of the periodic changes observed has been suggested.

Stieber, Joseph↗

NASA NTRS1995

Technology Of Controlled-Environment Agriculture

Report discusses controlled-environment agriculture (CEA) for commercial production of organisms, whether plants or animals. Practiced in greenhouses to produce food on nonarable lands. Describes conceptual regenerative system that incorporates biological, physical, and chemical processes to support humans in extraterrestrial environments.

Bubenheim, David L.↗

NASA NTRS1995

Spectral Changes in Metal Halide and High-pressure Sodium Lamps Equipped with Electronic Dimming

Electronic dimming of high-intensity discharge lamps offers control of photosynthetic photon flux (PPF) but is often characterized as causing significant spectral changes. Growth chambers with 400-W metal halide (MH) and high-pressure sodium (HPS) lamps were equipped with a dimmer system using silicon-controlled rectifiers (SCR) as high-speed switches. Phase control operation turned the line power off for some period of the alternating current cycle. At full power, the electrical input to HPS and MH lamps was 480 W (root mean squared) and could be decreased to 267 W and 428 W, respectively, before the arc was extinguished. Concomitant with this decrease in input power, PPF decreased by 60% in HPS and 50% in MH. The HPS lamp has characteristic spectral peaks at 589 and 595 nm. As power to the HPS lamps was decreased, the 589-nm peak remained constant while the 595-nm peak decreased, equaling the 589-nm peak at 345-W input, and the 589-nm peak was almost absent at 270-W input. The MH lamp has a broader spectral output but also has a peak at 589 nm and another smaller peak at 545 nm. As input power to the MH lamps decreased, the peak at 589 diminished to equal the 545-nm peak. As input power approached 428 W, the 589-nm peak shifted to 570 nm. While the spectrum changed as input power was decreased in the MH and HPS lamps, the phytochrome equilibrium ratio (P(sub fr):P(sub tot)) remains unchanged for both lamp types.

Bubenheim, David L.↗

NASA NTRS1995

Spectral Changes in Metal Halide and High-Pressure Sodium Lamps Equipped with Electronic Dimming

Electronic dimming of high-intensity discharge lamps offers control of Photosynthetic Photon Flux (PPF) but is often characterized as causing significant spectral changes. Growth chambers with 400-W Metal Halide (MH) and High-Pressure Sodium (HPS) lamps were equipped with a dimmer system using Silicon-Controlled Rectifiers (SCR) as high-speed switches. Phase control operation turned the line power off for some period of the alternating current cycle. At full power, the electrical input to HPS and MH lamps was 480 W (root mean squared) and could be decreased to 267 W and 428 W, respectively, before the arc was extinguished. Concomitant with this decrease in input power, PPF decreased by 60% in HPS and 50% in MH. The HPS lamp has characteristic spectral peaks at 589 and 595 nm. As power to the HPS lamps was decreased, the 589-nm peak remained constant while the 595-nm peak decreased, equaling the 589-nm peak at 345-W input, and 589-nm peak was almost absent at 270-W input. The MH lamp has a broader spectral output but also has a peak at 589 nm and another smaller peak at 545 nm. As input power approached 428 W, the 589-nm peak shifted to 570 nm. While the spectrum changed as input power was decreased in the MH and HPS lamps, the phytochrome equilibrium ratio (P(sub ft):P(sub tot)) remains unchanged for both lamp types.

Bubenheim, David L.↗

NASA NTRS1995

Incineration as a Method for Resource Recovery from Inedible Biomass in a Controlled Ecological Life Support System

Resource recovery from waste streams in a space habitat is essential to minimize the resupply burden and achieve self-sufficiency. In a Controlled Ecological Life Support System (CELSS) human wastes and inedible biomass will represent significant sources of secondary raw materials necessary for support of crop plant production (carbon, water, and inorganic plant nutrients). Incineration, pyrolysis, and water extraction have been investigated as candidate processes for recovery of these important resources from inedible biomass in a CELSS. During incineration CO2 is produced by oxidation of the organic components and this product can be directly utilized by plants. Water is concomitantly produced, requiring only a phase change for recovery. Recovery of inorganics is more difficult, requiring solubilization of the incinerator ash. The process of incineration followed by water solubilization of ash resulted in loss of 35% of the inorganics originally present in the biomass. Losses were attributed to volatilization (8%) and non-water-soluble ash (27%). All of the ash remaining following incineration could be solubilized with acid, with losses resulting from volatilization only. The recovery for individual elements varied. Elemental retention in the ash ranged from 100% of that present in the biomass for Ca, P, Mg, Na, and Si to 10% for Zn. The greatest water solubility was observed for potassium with recovery of approximately 77% of that present in the straw. Potassium represented 80% of the inorganic constituents in the wheat straw, and because of slightly greater solubility made up 86% of the water-soluble ash. Following incineration of inedible biomass from wheat, 65% of the inorganics originally present in the straw were recovered by water solubilization and 92% recovered by acid solubilization. Recovery of resources is more complex for pyrolysis and water extraction. Recovery of carbon, a resource of greater mass than the inorganic component of biomass, is more difficult following pyrolysis and water extraction of biomass. In both cases, additional processors would be required to provide products equivalent to those resulting from incineration alone. The carbon, water, and organic resources of inedible biomass are effectively separated and output in usable forms through incineration.

Bubenheim, David L.↗

NASA NTRS1995

Application of NASA's Advanced Life Support Technologies for Waste Treatment, Water Purification and Recycle, and Food Production in Polar Regions

NASA's advanced life support technologies are being combined with Arctic science and engineering knowledge to address the unique needs of the remote communities of Alaska through the Advanced Life Systems for Extreme Environments (ALSEE) project. ALSEE is a collaborative effort involving NASA, the State of Alaska, the University of Alaska, the North Slope Borough of Alaska, and the National Science Foundation (NSF). The focus is a major issue in the state of Alaska and other areas of the Circumpolar North, the health and welfare of its people, their lives and the subsistence lifestyle in remote communities, economic opportunity, and care for the environment. The project primarily provides treatment and reduction of waste, purification and recycling of water. and production of food. A testbed is being established to demonstrate the technologies which will enable safe, healthy, and autonomous function of remote communities and to establish the base for commercial development of the resulting technology into new industries. The challenge is to implement the technological capabilities in a manner compatible with the social and economic structures of the native communities, the state, and the commercial sector. Additional information is contained in the original extended abstract.

Bubenheim, David L.↗

NASA NTRS1995

Advanced Life Systems for Extreme Environments: An Arctic Application

The problems of obtaining adequate pure drinking water and disposing of liquid and solid waste in the U.S. Arctic, a region where virtually all water is frozen solid for much of the year, has led to unsanitary solutions (U.S. Arctic Research Commission). These solutions are also damaging to the environment. Sanitation and a safe water supply are particularly problems in rural villages. About one-fourth of Alaska's 86.000 Native residents live in these communities. They are without running water and use plastic buckets for toilets. The outbreak of diseases is believed to be partially attributable to exposure to human waste. Villages with the most frequent outbreaks of disease are those in which running water is difficult to obtain (Office of Technology Assessment, 1994). Waste is emptied into open lagoons, rivers, or onto the sea coast. It does not degrade rapidly and in addition to affecting human health, can be harmful to the fragile ecology of the Arctic and the indigenous wildlife and fish populations. Advanced Life Systems for Extreme Environments (ALSEE) provides a solution to sanitation and safe water problems. The system uses an advanced integrated technology developed for Antarctic and space applications. ALSEE uses the systems approach to address more than waste and water problems. By incorporating hydroponic horticulture and aquaculture into the waste treatment system, ALSEE addresses the quality and quantity of fresh foods available to Arctic residents. A temperate climate is required for year-round plant growth. ALSEE facilities can be designed to include a climate controlled area within the structure. This type of environment is a change from the long periods of darkness and cold found in the Arctic and can help alleviate stress so often associated with these extremes. While the overall concept of ALSEE projects is advanced, system facilities can be operated by village residents with appropriate training. ALSEE provides continuing training and education as a part of the project. Not only is this desirable but necessary. There is ample evidence in "gravoyard" throughout rural Alaska of technologies which failed not because they were not applic4tble, but because they were not integrated and could not be operated or repaired by village residents. Waste streams in villages will vary depending on the human diet and the non-food waste stream. ALSEE units can be adapted to different village situations once the content of the waste stream is known. Units located in population hubs can serve as research, education. and demonstration centers. Appropriate modifications can be determined at these centers to transfer technology to more remote locations where waste stream conditions may differ.

Lewis, Carol E.↗

NASA NTRS1994

The controlled ecological life support system Antarctic analog project: Analysis of wastewater from the South Pole Station, Antarctica, volume 1

The Controlled Ecological Life Support system (CELSS) Antarctic Analog Project (CAAP) is a joint National Science Foundation (NSF) and NASA project for the development, deployment and operation of CELSS technologies at the Amundsen-Scott South Pole Station. NASA goals are operational testing of CELSS technologies and the conduct of scientific studies to facilitate technology selection and system design. The NSF goals are that the food production, water purification, and waste treatment capabilities which will be provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, and minimize environmental impacts associated with human presence on the polar plateau. This report presents an analysis of wastewater samples taken from the Amundsen-Scott South Pole Station, Antarctica. The purpose of the work is to develop a quantitative understanding of the characteristics of domestic sewage streams at the South Pole Station. This information will contribute to the design of a proposed plant growth/waste treatment system which is part of the CELSS Antarctic Analog Project (CAAP).

Flynn, Michael T.↗

NASA NTRS1994

The CELSS Antarctic Analog Project: An Advanced Life Support Testbed at the Amundsen-Scott South Pole Station, Antarctica

CELSS Antarctic Analog Project (CAAP) represents a logical solution to the multiple objectives of both the NASA and the National Science Foundation (NSF). CAAP will result in direct transfer of proven technologies and systems, proven under the most rigorous of conditions, to the NSF and to society at large. This project goes beyond, as it must, the generally accepted scope of CELSS and life support systems including the issues of power generation, human dynamics, community systems, and training. CAAP provides a vivid and starkly realistic testbed of Controlled Ecological Life Support System (CELSS) and life support systems and methods. CAAP will also be critical in the development and validation of performance parameters for future advanced life support systems.

Straight, Christian L.↗

NASA NTRS1994

CELSS Antarctic Analog Project (CAAP): A New Paradigm for Polar Life Support and CELSS Research

The CELSS Antarctic Analog Project (CAAP) is a joint National Science Foundation (NSF) and National Aeronautics and Space Administration (NASA) project for the development, deployment and operation of CELSS technologies at the Amundsen-Scott South Pole Station. CAAP is implemented through the joint NSF/NASA Antarctic Space Analog Program (ASAP), initiated to support the pursuit of future NASA missions and to promote the transfer of space technologies to the NSF. Under a Memorandum of Agreement, the CAAP represents an example of a working dual agency cooperative project. NASA goals are operational testing of CELSS technologies and the conduct of scientific study to facilitate . technology selection, system design and methods development, including human dynamics as required for the operation of a CELSS. Although not fully closed, food production, water purification, and waste recycle and reduction provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, and minimize environmental impacts associated with human presence on the polar plateau. The CAAP facility will be highly integrated with the new South Pole Station infrastructure and will be composed of a deployed hardware facility and a research activity. This paper will include a description of CAAP and its functionality, conceptual designs, component selection and sizing for the crop growth chamber, crop production expectations, and a brief report on an initial on-site visit. This paper will also provide a discussion of issues associated with power and energy use and the applicability of CAAP to direct technology transfer to society in general and remote communities in particular.

Bubenheim, David L.↗

NASA NTRS1994

Suitability of Gray Water for Hydroponic Crop Production Following Biological and Physical Chemical and Biological Subsystems

The water present in waste streams from a human habitat must be recycled in Controlled Ecological Life Support Systems (CELSS) to limit resupply needs and attain self-sufficiency. Plants play an important role in providing food, regenerating air, and producing purified water via transpiration. However, we have shown that the surfactants present in hygiene waste water have acute toxic effects on plant growth (Bubenheim et al. 1994; Greene et al., 1994). These phytotoxic affects can be mitigated by allowing the microbial population on the root surface to degrade the surfactant, however, a significant suppression (several days) in crop performance is experienced prior to reaching sub-toxic surfactant levels and plant recovery. An effective alternative is to stabilize the microbial population responsible for degradation of the surfactant on an aerobic bioreactor and process the waste water prior to utilization in the hydroponic solution (Wisniewski and Bubenheim, 1993). A sensitive bioassay indicates that the surfactant phytotoxicity is suppressed by more than 90% within 5 hours of introduction of the gray water to the bioreactor; processing for more than 12 hours degrades more than 99% of the phytotoxin. Vapor Compression Distillation (VCD) is a physical / chemical method for water purification which employees sequential distillation steps to separate water from solids and to volatilize contaminants. The solids from the waste water are concentrated in a brine and the pure product water (70 - 90% of the total waste water volume depending on operating conditions) retains non of the phytotoxic effects. Results of the bioassay were used to guide evaluations of the suitability of recovered gray water following biological and VCD processing for hydroponic lettuce production in controlled environments. Lettuce crops were grown for 28 days with 100% of the input water supplied with recovered water from the biological processor or VCD. When compared with the growth of plants in control hydroponic solution containing pure deionized water, no growth difference could be measured resulting from any of the recovered water treatments. Both biological treatment and VCD offer alternative technology approaches to recovering water from waste streams appropriate for input into a crop production system. A high level of crop performance (food, air, and water production) can be maintained with either processor; selection decisions can be based on other factors regarding system integration.

Bubenheim, David L.↗

NASA NTRS1993

Quinoa: An emerging new crop with potential for CELSS

Chenopodium quinoa is being considered as a new crop for the Controlled Ecological Life Support System (CELSS) because of its high protein values (12 - 18%) and unique amino acid composition. Lysine, and essential amino acid that is deficient in many grain crops, is found in quinoa approaching Food and Agriculture Organization of the United Nations (FAO) standards set for humans. This 'new' crop, rich in protein and with desirable proportions of important amino acids, may provide greater versatility in meeting the needs of humans on long-term space missions. Initially, the cultivars CO407 x ISLUGA, CO407 Heat Tolerant Population 1, and Real' (a Bolivian variety) were examined. The first cultivar showed the most promise in greenhouse studies. When grown hydroponically in the greenhouse, with no attempt to maximize productivity, this cultivar produced 202 g m(exp -2) with a harvest index of 37%. None of the cultivars were greater than 70 cm in height. Initial results indicate that quinoa could be an excellent crop for CELSS because of the high concentration of protein, ease of use, versatility in preparation, and potential for greatly increased yields in controlled environments.

Schlick, Greg↗

NASA NTRS1991

Applications of CELSS technology to controlled environment agriculture

Controlled environment agriculture (CEA) is defined as the use of environmental manipulation for the commercial production of organisms, whether plants or animals. While many of the technologies necessary for aquaculture systems in North America is nevertheless doubling approximately every five years. Economic, cultural, and environmental pressures all favor CEA over field production for many non-commodity agricultural crops. Many countries around the world are already dependent on CEA for much of their fresh food. Controlled ecological life support systems (CELSS), under development at ARC, KSC, and JSC expand the concept of CEA to the extent that all human requirements for food, oxygen, and water will be provided regenerated by processing of waste streams to supply plant inputs. The CELSS will likely contain plants, humans, possibly other animals, microorganisms and physically and chemical processors. In effect, NASA will create engineered ecosystems. In the process of developing the technology for CELSS, NASA will develop information and technology which will be applied to improving the efficiency, reliability, and cost effectiveness for CEA, improving its resources recycling capabilities, and lessening its environmental impact to negligible levels.

Bates, Maynard E.↗

NASA NTRS1990

Environmental modification of yield and food composition of cowpea and leaf lettuce

Cowpea (Vigna unguiculata (L.) Walp.) and leaf lettuce (Lactuca sativa L.) are candidate species to provide ligume protein and starch or serve as a salad base for a nutritionally balanced and psychologically satisfying vegetarian diet in the Controlled Ecology Life Support System (CELSS). Various nutritional parameters are reported. Hydroponic leaf lettuce grew best under CO2 enrichment and photosynthetic photon flux (PPF) enhancement. Leaf protein content reached 36 percent with NH4(+) + NO3 nutrition; starch and free sugar content was as high as 7 or 8.4 percent of DW, respectively, for high PPF/CO2 enriched environments.

Mitchell, Cary A.↗

NASA NTRS1990

The crop growth research chamber: A ground-based facility for CELSS research

A ground based facility for the study of plant growth and development under stringently controlled environments is being developed by the Closed Ecological Life Support System (CELSS) program at the Ames Research Center. Several Crop Growth Research Chambers (CGRC) and laboratory support equipment provide the core of this facility. The CGRC is a closed (sealed) system with a separate recirculating atmosphere and nutrient delivery systems. The atmospheric environment, hydroponic environment, systems controls, and data acquisition are discussed.

Bubenheim, David L.↗

NASA NTRS1989

The Crop Growth Research Chamber - A ground-based facility for CELSS research

Crop Growth Research Chambers (CGRCs) are being developed as CELSS research facilities for the NASA/Ames Research Center. The history of the CGRC project is reviewed, noting the applications of CGRC research for the development of the Space Station. The CGRCs are designed for CELSS research and development, system control and integration, and flight hardware design and experimentation. The atmospheric and hydroponic environments of the CGRC system are described and the science requirements for CGRC environmental control are listed.

Bubenheim, David L.↗