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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Optimization of moisture content for wheat seedling germination in a cellulose acetate medium for a space flight experiment

The Porous Tube Plant Nutrient Delivery System (PTPNDS), a hydrophilic, microporous ceramic tube hydroponic system designed for microgravity, will be tested in a middeck locker of the Space Shuttle. The flight experiment will focus on hardware operation and assess its ability to support seed germination and early seedling growth in microgravity. The water controlling system of the PTPNDS hardware has been successfully tested during the parabolic flight of the KC-135. One challenge to the development of the space flight experiment was to devise a method of holding seeds to the cylindrical porous tube. The seed-holder must provide water and air to the seed, absorb water from the porous tube, withstand sterilization, provide a clear path for shoots and roots to emerge, and be composed of flight qualified materials. In preparation for the flight experiment, a wheat seed-holder has been designed that utilizes a cellulose acetate plug to facilitate imbibition and to hold the wheat seeds in contact with the porous tube in the correct orientation during the vibration of launch and the microgravity environment of orbit. Germination and growth studies with wheat at a range of temperatures showed that optimal moisture was 78% (by weight) in the cellulose acetate seed holders. These and other design considerations are discussed.

NASA Discipline Number 61-20↗
NASA NTRS1987

Irradiance and spectral distribution control system for controlled environment chambers

This paper describes a closed-loop control system for controlling the irradiance and spectral quality generated by fluorescent lamps in a controlled environment chamber. The 400 to 800 nm irradiance and the ratio of the red waveband (600 to 700 nm) to the far-red waveband (700 to 800 nm) were independently controlled and varied as functions of time. A suggested application is to investigate the possibility of synergistic effects of changing irradiance levels and changing spectral distributions on photoperiodism and photomorphogenesis.

NASA Center KSC↗
NASA NTRS1998

A recirculating hydroponic system for studying peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.

NASA Center KSC↗
NASA NTRS2000

Low potassium enhances sodium uptake in red-beet under moderate saline conditions

Due to the discrepancy in metabolic sodium (Na) requirements between plants and animals, cycling of Na between humans and plants is limited and critical to the proper functioning of bio-regenerative life support systems, being considered for long-term human habitats in space (e.g., Martian bases). This study was conducted to determine the effects of limited potassium (K) on growth, Na uptake, photosynthesis, ionic partitioning, and water relations of red-beet (Beta vulgaris L. ssp. vulgaris) under moderate Na-saline conditions. Two cultivars, Klein Bol, and Ruby Queen were grown for 42 days in a growth chamber using a re-circulating nutrient film technique where the supplied K levels were 5.0, 1.25, 0.25, and 0.10 mM in a modified half-strength Hoagland solution salinized with 50 mM NaCl. Reducing K levels from 5.0 to 0.10 mM quadrupled the Na uptake, and lamina Na levels reached -20 g kg-1 dwt. Lamina K levels decreased from -60 g kg-1 dwt at 5.0 mM K to -4.0 g kg-1 dwt at 0.10 mM K. Ruby Queen and Klein Bol responded differently to these changes in Na and K status. Klein Bol showed a linear decline in dry matter production with a decrease in available K, whereas for cv. Ruby Queen, growth was stimulated at 1.25 mM K and relatively insensitive to a further decreases of K down to 0.10 mM. Leaf glycinebetaine levels showed no significant response to the changing K treatments. Leaf relative water content and osmotic potential were significantly higher for both cultivars at low-K treatments. Leaf chlorophyll levels were significantly decreased at low-K treatments, but leaf photosynthetic rates showed no significant difference. No substantial changes were observed in the total cation concentration of plant tissues despite major shifts in the relative Na and K uptake at various K levels. Sodium accounted for 90% of the total cation uptake at the low K levels, and thus Na was likely replacing K in osmotic functions without negatively affecting the plant water status, or growth. Our results also suggest that cv. Ruby Queen can tolerate a much higher Na tissue concentration than cv. Klein Bol before there is any growth reduction. Grant numbers: 12180.

NASA Center KSC↗
NASA NTRS2000

Determination of anionic surfactants during wastewater recycling process by ion pair chromatography with suppressed conductivity detection

A direct approach utilizing ion pairing reversed-phase chromatography coupled with suppressed conductivity detection was developed to monitor biodegradation of anionic surfactants during wastewater recycling through hydroponic plant growth systems and fixed-film bioreactors. Samples of hydroponic nutrient solution and bioreactor effluent with high concentrations (up to 120 mS electrical conductance) of inorganic ions can be analyzed without pretreatment or interference. The presence of non-ionic surfactants did not significantly affect the analysis. Dynamic linear ranges for tested surfactants [Igepon TC-42, ammonium lauryl sulfate, sodium laureth sulfate and sodium alkyl (C10-C16) ether sulfate] were 2 to approximately 500, 1 to approximately 500, 2.5 to approximately 550 and 3.0 to approximately 630 microg/ml, respectively.

NASA Program Advanced Human Support Technology↗
NASA NTRS2000

Preliminary development and evaluation of an algae-based air regeneration system

The potential of air regeneration system based on the growth of microalgae on the surface of porous ceramic tubes is evaluated. The algae have been maintained in the system for extended periods, up to 360 days. Preliminary measurements of the photosynthetic capacity have been made for Chlorella vulgaris (UTEX 259), Neospongiococcum punctatum (UTEX 786), Stichococcus sp., and Gloeocapsa sp. Under standard test conditions (photosynthetic photon flux approximately 66 micromoles m-2 s-1, initial CO2 concentration approximately 450 micromoles mol-1), mature tubes remove up to 0.2 micromoles of CO2 per tube per minute. The rate of removal increases with photon flux up to at least 225 micromoles m-2 s-1 (PPF); peak rates of 0.35 micromoles of CO2 per tube per minute have been achieved with Chlorella vulgaris. These rates correspond to between 120 and 210 micromoles of CO2 removed per square meter of projected area per minute.

Non-NASA Center↗
NASA NTRS2001

A microwave-powered sterilizable interface for aseptic access to bioreactors that are vulnerable to microbial contamination

Novel methods and apparatus that employ the rapid heating characteristics of microwave irradiation to facilitate the aseptic transfer of nutrients, products, and other materials between microbially sensitive systems and the external environment are described. The microwave-sterilizable access port (MSAP) consists of a 600-W magnetron emitting at a frequency of 2.45 GHz, a sterilization chamber with inlet and outlet flow lines, and a specimen transfer interface. Energy is routed to the sterilization chamber via a coaxial transmission line where small quantities of water couple strongly with the incident radiation to produce a superheated vapor phase. The efficiency of energy transfer is enhanced through the use of microwave susceptors within the sterilization chamber. Mating surfaces are thermally sterilized through direct contact with the hot gas. Efficacy has been demonstrated using the thermophile Bacillus stearothermophilus.

Validation Studies↗
NASA NTRS2001

Nitrate concentration effects on NO3-N uptake and reduction, growth, and fruit yield in strawberry

Strawberries (Fragaria xananassa Duch. 'Osogrande') were grown hydroponically with three NO3-N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO3-N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO3-N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO3-N concentration in the hydroponics system increased. Tissue NO3- concentration also increased as external NO3-N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO3-N concentration on NR activities in leaves or roots during either stage of development. Leaf NR activity averaged approximately 360 nmol NO2 formed/g fresh weight (FW)/h over both developmental stages, while NR activity in roots was much lower, averaging approximately 115 nmol NO2 formed/g FW/h. Vegetative organ FW, dry weight (DW), and total fruit yield were unaffected by NO3-N concentration. These data suggest that the inability of strawberry to increase growth and fruit yield in response to increasing NO3-N concentrations is not due to limitations in NO3-N uptake rates, but rather to limitations in NO3- reduction and/or assimilation in both roots and leaves.

NASA Center KSC↗
NASA NTRS2005

A comparison of soil moisture sensors for space flight applications

Plants will be an important part of future long-term space missions. Automated plant growth systems require accurate and reliable methods of monitoring soil moisture levels. There are a number of different methods to accomplish this task. This study evaluated sensors using the capacitance method (ECH2O), the heat-pulse method (TMAS), and tensiometers, compared to soil water loss measured gravimetrically in a side-by-side test. The experiment monitored evaporative losses from substrate compartments filled with 1- to 2-mm baked calcinated clay media. The ECH2O data correlated well with the gravimetric measurements, but over a limited range of soil moisture. The averaged TMAS sensor data overstated soil moisture content levels. The tensiometer data appeared to track evaporative losses in the 0.5- to 2.5-kPa range of matric potential that corresponds to the water content needed to grow plants. This small range is characteristic of large particle media, and thus high-resolution tensiometers are required to distinguish changing moisture contents in this range.

NASA Center KSC↗
NASA NTRS1999

Low irradiances affect abscisic acid, indole-3-acidic acid, and cytokinin levels of wheat (Triticum aestivum L.) tissues

Wheat (Triticum aestivum L.) plants were grown under four irradiance levels: 1,400, 400, 200, and 100 micromol m-2 s-1. Leaves and roots were sampled before, during, and after the boot stage, and levels of abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin, zeatin riboside, dihydrozeatin, dihydrozeatin riboside, isopentenyl adenine, and isopentenyl adenosine were quantified using noncompetitive indirect ELISA systems. Levels of IAA in leaves and roots of plants exposed to 100 micromol m-2 s-1 of irradiance were 0.7 and 2.9 micromol kg-1 dry mass (DM), respectively. These levels were 0.2 and 1.0 micromol kg-1 DM, respectively, when plants were exposed to 1,400 micromol m-2 s-1. Levels of ABA in leaves and roots of plants exposed to 100 micromol m-2 s-1 were 0.65 and 0.55 micromol kg-1 DM, respectively. They were 0.24 micromol kg-1 DM (both leaves and roots) when plants were exposed to 1,400 micromol m-2 s-1. Levels of isopentenyl adenosine in leaves (24.3 nmol kg-1 DM) and roots (29.9 nmol kg-1 DM) were not affected by differences in the irradiance regime. Similar values were obtained in a second experiment. Other cytokinins could not be detected (<10 nmol kg 1 DM) in either experiment with the sample sizes used (150-600 mg DM for roots and shoots, respectively).

Non-NASA Center↗
NASA NTRS1999

Adsorption processes in spacecraft environmental control and life support systems

The environmental control and life support system on a spacecraft maintains a safe and comfortable environment in which the crew can live and work by supplying oxygen and water and by removing carbon dioxide, water vapor, and trace contaminants from cabin air. Although open-loop systems have been used successfully in the past for short-duration missions, the economics of current and future long-duration missions in space will make nearly complete recycling of air and water imperative. A variety of operations will be necessary to achieve the goal of nearly complete recycling. These include separation and reduction of carbon dioxide, removal of trace gas-phase contaminants, recovery and purification of humidity condensate, purification and polishing of wastewater streams, and others. Several of these can be performed totally or in part by adsorption processes. These processes are good candidates to perform separations and purifications in space due to their gravity independence, high reliability, relative high energy efficiency, design flexibility, technological maturity, and regenerative nature. For these reasons, adsorption has historically played a key role in life support on U.S. and Russian piloted spacecraft. Among the life support applications that can be achieved through use of adsorption technology are removal of trace contaminants and carbon dioxide from cabin air and recovery of potable water from waste streams. In each of these cases adsorption technology has been selected for use onboard the International Space Station. The requirements, science, and hardware for these applications are discussed. Human space exploration may eventually lead to construction of planetary habitats. These habitats may provide additional opportunities for use of adsorption processes, such as control of greenhouse gas composition, and may have different resources available to them, such as gases present in the planetary atmosphere. Separation and purification processes based on adsorption can be expected to continue to fulfill environmental control and life support needs on future missions.

Review, Tutorial↗
NASA NTRS1994

Yield and seed oil content response of dwarf, rapid-cycling Brassica to nitrogen treatments, planting density, and carbon dioxide enrichment

Effects of N level (15 to 30 mM), time of N increase (14 to 28 days after planting), and planting density (1163 to 2093 plants/m2) were determined for crop yield responses of dwarf, rapid-cycling brassica (Brassica napus L., CrGC 5-2, Genome: ACaacc). Crops were grown in solid-matrix hydroponic systems and under controlled-environment conditions, including nonsupplemented (ambient) or elevated CO2 concentrations (998 +/- 12 micromoles mol-1). The highest seed yield rate obtained (4.4 g m-2 day-1) occurred with the lowest N level (15 mM) applied at the latest treatment time (day 28). In all trials, CO2 enrichment reduced seed yield rate and harvest index by delaying the onset of flowering and senescence and stimulating vegetative shoot growth. The highest shoot biomass accumulation rate (55.5 g m-2 day-1) occurred with the highest N level (30 mM) applied at the earliest time (day 14). Seed oil content was not significantly affected by CO2 enrichment. Maximum seed oil content (30% to 34%, dry weight basis) was obtained using the lowest N level (15 mM) initiated at the latest treatment time (day 28). In general, an increase in seed oil content was accompanied by a decrease in seed protein. Seed carbohydrate, moisture, and ash contents did not vary significantly in response to experimental treatments. Effects of N level and time of N increase were consistently significant for most crop responses. Planting density was significant only under elevated CO2 conditions.

Non-NASA Center↗
NASA NTRS2001

Beneficial effects of humic acid on micronutrient availability to wheat

Humic acid (HA) is a relatively stable product of organic matter decomposition and thus accumulates in environmental systems. Humic acid might benefit plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA on growth and micronutrient uptake in wheat (Triticum aestivum L.) grown hydroponically. Four root-zone treatments were compared: (i) 25 micromoles synthetic chelate N-(4-hydroxyethyl)ethylenediaminetriacetic acid (C10H18N2O7) (HEDTA at 0.25 mM C); (ii) 25 micromoles synthetic chelate with 4-morpholineethanesulfonic acid (C6H13N4S) (MES at 5 mM C) pH buffer; (iii) HA at 1 mM C without synthetic chelate or buffer; and (iv) no synthetic chelate or buffer. Ample inorganic Fe (35 micromoles Fe3+) was supplied in all treatments. There was no statistically significant difference in total biomass or seed yield among treatments, but HA was effective at ameliorating the leaf interveinal chlorosis that occurred during early growth of the nonchelated treatment. Leaf-tissue Cu and Zn concentrations were lower in the HEDTA treatment relative to no chelate (NC), indicating HEDTA strongly complexed these nutrients, thus reducing their free ion activities and hence, bioavailability. Humic acid did not complex Zn as strongly and chemical equilibrium modeling supported these results. Titration tests indicated that HA was not an effective pH buffer at 1 mM C, and higher levels resulted in HA-Ca and HA-Mg flocculation in the nutrient solution.

Non-NASA Center↗
NASA NTRS2002

NASA food systems: past, present, and future

The development of space food has been evolving since the Soviet cosmonaut, German Titov, became the first human to eat in space in August 1961. John Glenn was the first American to consume food, applesauce, on the third manned Mercury mission in August 1962. Before these events, there was no knowledge that humans would be able to swallow and, hence, eat in weightlessness. Space food development began with highly engineered foods that met rigid requirements imposed by spacecraft design and short mission durations. Improvements in the habitability of the spacecraft have permitted improvements in the quality of space food. As the missions became longer, the need for better nutrition, more variety, and easily consumable foods also became more important. Currently, the International Space Station astronauts have a wide variety of foods. The goal is to provide acceptable foods that taste similar to foods we eat here on Earth. Extended planetary stays will require even more variety and more technologic advances. Plants will be grown to recycle the air and water and will provide food for the crew. These harvested crops will need to be processed into safe, healthy, and acceptable food ingredients that can then be prepared into menu items.

short duration↗
NASA NTRS2001

Using mini-rockwool blocks as growing media for limited-cluster tomato production

Rockwool is an excellent growing medium for the hydroponic production of tomato; however, the standard size rockwool blocks [4 x 4 x 2.5 inches (10 x 10 x 6.3 cm) or 3 x 3 x 2.5 inches (7.5 x 7.5 x 6.3 cm)] are expensive. The following experiments were conducted with less expensive minirock wool blocks (MRBs), on rayon polyester material (RPM) as a bench top liner, to reduce the production cost of tomatoes (Lycopersicon esculentum) grown in a limited-cluster, ebb and flood hydroponic cultivation system. Fruit yield for single-cluster plants growing in MRBs [2 x 2 x 1.6 inches (5 x 5 x 4 cm) and 1.6 x 1.6 x 1.6 inches (4 x 4 x 4 cm)] was not significantly different from plants grown in larger sized blocks (3 x 3 x 2.5 inches). When the bench top was lined with RPM, roots penetrated the RPM, and an extensive root mat developed between the RPM and the bench top. The fruit yield from plants on RPM was significantly increased compared to plants without RPM due to increases in fruit size and fruit number. RPM also significantly reduced the incidence of blossom-end rot. In a second experiment, single- and double-cluster plants were grown on RPM. Fruit yield for double-cluster plants was 40% greater than for single-cluster plants due to an increase in fruit number, although the fruit were smaller in size. As in the first experiment, fruit yield for all plants grown in MRBs was not significantly different from plants grown in the larger sized blocks. MRBs and a RPM bench liner are an effective combination in the production of limited-cluster hydroponic tomatoes.

Non-NASA Center↗
NASA NTRS1997

Response of the water status of soybean to changes in soil water potentials controlled by the water pressure in microporous tubes

Water transport through a microporous tube-soil-plant system was investigated by measuring the response of soil and plant water status to step change reductions in the water pressure within the tubes. Soybeans were germinated and grown in a porous ceramic 'soil' at a porous tube water pressure of -0.5 kpa for 28 d. During this time, the soil matric potential was nearly in equilibrium with tube water pressure. Water pressure in the porous tubes was then reduced to either -1.0, -1.5 or -2.0 kPa. Sap flow rates, leaf conductance and soil, root and leaf water potentials were measured before and after this change. A reduction in porous tube water pressure from -0.5 to -1.0 or -1.5 kPa did not result in any significant change in soil or plant water status. A reduction in porous tube water pressure to -2.0 kPa resulted in significant reductions in sap flow, leaf conductance, and soil, root and leaf water potentials. Hydraulic conductance, calculated as the transpiration rate/delta psi between two points in the water transport pathway, was used to analyse water transport through the tube-soil-plant continuum. At porous tube water pressures of -0.5 to-1.5 kPa soil moisture was readily available and hydraulic conductance of the plant limited water transport. At -2.0 kPa, hydraulic conductance of the bulk soil was the dominant factor in water movement.

NASA Center JSC↗
NASA NTRS1993

A data base of crop nutrient use, water use, and carbon dioxide exchange in a 2O square meter growth chamber: I. Wheat as a case study

A data set is given describing the daily nutrient uptake, gas exchange, environmental conditions, and carbon (C), and nutrient partitioning at harvest for the entire canopy and root system of a wheat crop (Triticum aestivum, cv. Yecora Rojo). The data were obtained from a 20 m2 stand of wheat plants grown from planting to maturity in a closed, controlled environment, and include daily nutrient uptake [macronutrients, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S); and micronutrients, iron (Fe), boron (B), manganese (Mn), zinc (Zn), copper (Cu), and molybdenum (Mo)], canopy carbon dioxide (CO2) exchange rates, and transpiration. Environmental factors such as relative humidity, air temperature, nutrient solution temperature, pH and electrical conductivity, and photoperiod were controlled in the chamber to specific set points. A detailed description of biomass yield for each of the 64 plant growth trays comprising the 20 m2 of growth area is also provided, and includes dry weights of grain, straw, chaff, and roots, along with the concentration of nutrients in different plant tissues and the percent carbohydrate, fat, and protein. To our knowledge, this information represents one of the most extensive data sets available for a canopy of wheat grown from seed to maturity under controlled environmental and nutritional conditions, and thus may provide useful information for model development and validation. 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 indicating when adjustments in set points and occasional equipment or sensor failures occurred.

NASA Discipline Number 61-20↗
NASA NTRS1994

Ammonium and nitrate uptake by soybean during recovery from nitrogen deprivation

Soybean [Glycine max (L.) Merrill] plants that had been subjected to 15 d of nitrogen deprivation were resupplied for 10 d with 1.0 mol m-3 nitrogen provided as NO3-, NH4+, or NH4(+) + NO3- in flowing hydroponic culture. Plants in a fourth hydroponic system received 1.0 mol m-3 NO3- during both stress and resupply periods. Concentrations of soluble carbohydrates and organic acids in roots increased 210 and 370%, respectively, during stress. For the first day of resupply, however, specific uptake rates of nitrogen, determined by ion chromatography as depletion from solution, were lower for stressed than for non-stressed plants by 43% for NO3- resupply, by 32% for NH4(+) + NO3- resupply, and 86% for NH4+ resupply. When specific uptake of nitrogen for stressed plants recovered to rates for non-stressed plants at 6 to 8 d after nitrogen resupply, carbohydrates and organic acids in their roots had declined to concentrations lower than those of non-stressed plants. Recovery of nitrogen uptake capacity of roots thus does not appear to be regulated simply by the content of soluble carbon compounds within roots. Solution concentrations of NH4+ and NO3- were monitored at 62.5 min intervals during the first 3 d of resupply. Intermittent 'hourly' intervals of net influx and net efflux occurred. Rates of uptake during influx intervals were greater for the NH4(+)-resupplied than for the NO3(-)-resupplied plants. For NH4(+)-resupplied plants, however, the hourly intervals of efflux were more numerous than for NO3(-)-resupplied plants. It thus is possible that, instead of repressing NH4+ influx, increased accumulation of amino acids and NH4+ in NH4(+)-resupplied plants inhibited net uptake by stimulation of efflux on NH4+ absorbed in excess of availability of carbon skeletons for assimilation. Entry of NH4+ into root cytoplasm appeared to be less restricted than translocation of amino acids from the cytoplasm into the xylem.

NASA Discipline Number 61-10↗