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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Autonomous Fueling System for Heavy-Duty Fuel Cell Electric Trucks

The motivation for this project stemmed from the challenges associated with rapidly refueling heavy-duty hydrogen fuel cell electric trucks (FCETs). Current manual refueling processes for fast refueling involve large, heavy equipment (e.g., hoses three times heavier than standard) and pose ergonomic risks and potential for equipment damage. The goal was to develop and test an autonomous fueling system to improve ergonomics, enhance safety, increase equipment durability through design improvements, and potentially speed up the fueling process. This project aimed to add to the understanding of autonomous systems in the context of heavy-duty hydrogen refueling, evaluating the technical effectiveness of potential concepts. A successfully developed system would benefit the public by facilitating the adoption of zero-emission heavy-duty transport, reducing reliance on manual labor for a physically demanding task, and potentially improving the safety and efficiency of hydrogen refueling infrastructure. The major accomplishment during the project's active period was the completion of the system-level architecture task. This involved establishing a detailed list of system requirements covering interfaces, environmental conditions, regulatory compliance, industry standards, safety, security, performance capabilities, and optional features. Five key use cases for the autonomous system were also identified. However, due to internal restructuring at Nikola, the necessary resources could not be allocated to continue the project. Consequently, Nikola opted to discontinue the project. The award was mutually terminated by Nikola and the DOE.

08 HYDROGEN↗
NASA NTRS1990

Gravitropism of cucumber hypocotyls: biophysical mechanism of altered growth

The biophysical basis for the changes in cell elongation rate during gravitropism was examined in aetiolated cucumber (Cucumis sativus L.) hypocotyls. Bulk osmotic pressures on the two sides of the stem and in the epidermal cells were not altered during the early time course of gravitropism. By the pressure-probe technique, a small increase in turgor (0.3 bar, 30 kPa) was detected on the upper (inhibited) side, whereas there was a negligible decrease in turgor on the lower (stimulated) side. These small changes in turgor and water potential appeared to be indirect, passive consequences of the altered growth and the small resistance for water movement from the xylem, and indicated that the change in growth was principally due to changes in wall properties. The results indicate that the hydraulic conductance of the water-transport pathway was large (.25 h-1 bar-1) and the water potential difference supporting cell expansion was no greater than 0.3 bar (30 kPa). From pressure-block experiments, it appeared that upon gravitropic stimulation (1) the yield threshold of the lower half of the stem did not decrease and (2) the wall on the upper side of the stem was not made more rigid by a cross-linking process. Mechanical measurements of the stress/strain properties of the walls showed that the initial development of gravitropism did not involve an alteration of the mechanical behaviour of the isolated walls. Thus, gravitropism in cucumber hypocotyls occurs principally by an alteration of the wall relaxation process, without a necessary change in wall mechanical properties.

Non-NASA Center↗
NASA NTRS1988

Effects of shoot inversion on stem structure in Pharbitis nil

The effects of shoot inversion on stem structure over 72 hr were investigated in Pharbitis nil by analyzing cell number, cell length, and the cross sectional areas of cells, tissues, and regions. An increase in stem diameter can be attributed to an increase in both cell number and cross sectional area of pith (primarily) and vascular tissue (secondarily). Qualitative observations of cell wall thickness in the light microscope did not reveal any significant effects of shoot inversion on this parameter. The inhibition of shoot elongation was accompanied by a significant decrease in cell length in the pith. The results are generally consistent with an ethylene effect on cell dimensions, especially in the pith.

Non-NASA Center↗
NASA NTRS1986

Modification of cytogenetic and physiological effects of space flight factors by biologically active compounds

Physiological and cytogenetic changes in the Welsh onion plants induced by a short (82 days) and long term (522 days) space flight are expressed in decrease of seed germination, inhibition of stem growth, depression of cell division in root meristem, and increase in the number of structural chromosome rearrangements. The treatment of such plants with solutions of a-tocopherol, auxin, and kinetin decreased the level of chromosome aberrations to the control one and normalized cell divisions and growth partly or completely.

Aliyev, A. A.↗
DOE OSTI2025

The three cellulose synthase isoforms for secondary cell wall make specific contributions to microfibril synthesis

Cellulose is synthesized at the plasma membrane by the cellulose synthase complex, a structure that contains three distinct isoforms of the catalytic subunit, cellulose synthase A (CESA). The division into three subunits appears early in land plant evolution and is highly conserved, particularly for the secondary cell wall. However, what if any unique roles each isoform plays in the complex remain unclear. Here, we assessed the contributions of specific isoforms to microfibril synthesis. First, we expressed CESA isoforms of the primary cell wall or the moss Physcomitrium patens in Arabidopsis thaliana backgrounds missing a secondary cell wall CESA. While the primary cell wall isoforms rescued the cesa knockout phenotype with partial isoform specificity, those from the moss rescued with fewer restrictions. Then, we recreated various CESA missense mutations in all three of the secondary cell wall isoforms; while results are consistent with isoform specificity, they are difficult to interpret further without molecular structures. Finally, we show that catalytically inactive CESA isoforms restore growth and cellulose content in the corresponding knockout in an isoform-specific manner; along with partial rescue of the growth and cellulose content of the inflorescence stem, the replacement lines have fiber cells with partially disorganized microfibrils and secondary cell wall cellulose with narrow crystal width. Generally, effects were more pronounced in lines where CESA8 was inactivated compared with inactivating CESA4 or 7, which tended to have similar phenotypes to each other. Here, we account for these results with a model for cellulose synthase structure with the isoforms assigned specific localization within the cellulose synthase complex.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1985

Gravitropism in Leafy Dicot Stems

A polarizing research microscope with rotating stage and associated camera equipment were ordered, and techniques of fixation and preparation of specimens were perfected for studying possible changes in orientation of cellulose microfibrils in cell walls of gravistimulated dicot stems. Acid ethephon solutions or acid without ethephon caused elongation of stem tissues where they were applied; stems bent away from the side of application. Acid solutions applied to the bottom of horizontal stems greatly delayed bending. Research in tissue sensitivity changes during gravitropic bending of soybean hypocotyls while immersed in auxin and in castor bean stems is also reported.

Salisbury, F. B.↗
NASA NTRS2002

Production of minimally disturbed synchronous cultures of hematopoietic cells

A method is describedforproducing sizable quantities of synchronously dividing, minimally disturbed mammalian cells. Cultures were grown immobilized on surfaces such that cell division within the population resulted in the continuous release of synchronous newborn cells. As judged by the quality and duration of synchronous growth, cell size distributions, and DNA compositions, newborn mouse L1210 cells grew with a very high level of synchrony without overt evidence of growth disturbances. The technology should be applicable to a variety of hematopoietic cells, as evidenced by similar results with human MOLT-4 and U937 cell lines.

Non-NASA Center↗
DOE OSTI2025

Comparing four heat-inducible promoters in stably transformed sugarcane regarding spatial and temporal control of transgene expression reveals candidates to drive stem-preferred transgene expression

Small heat shock protein (sHSP) promoters contain cis-regulatory elements that facilitate transcription in response to heat stress, making them valuable tools for functional studies through controlled gene expression and the precise regulation of gene-editing tools or morphogenic regulators. To evaluate their utility, GUS reporter gene expression driven by four plant-sourced HSP promoters (p GmHSP17.5 , p HvHSP17 , p ZmHSP17.7 , and p ZmHSP26 ) was compared across various tissues of stably transformed sugarcane before and after heat treatment. At 22°C, all promoters showed minimal activity in leaves and roots, although p ZmHSP17.7 and p HvHSP17 displayed moderate expression in stems. Following heat treatment, all promoters exhibited their highest activity in stems, followed by leaves and roots. In stem tissues, p GmHSP17.5 displayed heat-induced uidA expression comparable to the constitutive p ZmUbi promoter. Notably, heat-induced reporter gene activity in stem middle sections of single-copy transgenic lines containing p ZmHSP17.7 , p HvHSP17 , or p ZmHSP26 exceeded p ZmUbi -derived uidA activity by 9.7-fold, 3.8-fold, and 3.0-fold, respectively, with 346- to 3,672-fold induction compared to control conditions. Most promoters showed peak expression in the middle sections of the stem, while p HvHSP17 was the most active in the stem apices. Histochemical analysis revealed that p ZmHSP17.7 and p HvHSP17 were active in both parenchyma cells and vascular bundles within sugarcane stems. Among leaf tissues, mature leaves exhibited greater expression than senescing or immature leaves, while root activity remained consistently minimal across all promoters. Temperature-course experiments identified distinct activation thresholds: 34°C–36°C for p ZmHSP17.7 , 36°C for p ZmHSP26 , 36°C–38°C for p HvHSP17 , and 40°C–42°C for p GmHSP17.5 . Drought stress also induced reporter gene transcription in stems under HSP promoters, although with lower fold induction than heat treatment. These findings provide valuable tools for gene function studies and biotechnology applications, including heat stress tolerance research, controlled transgene expression in metabolic engineering, precision gene editing, and developmental biology studies.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1993

Gibberellin (GA3) enhances cell wall invertase activity and mRNA levels in elongating dwarf pea (Pisum sativum) shoots

The invertase (EC 3.2.1.26) purified from cell walls of dwarf pea stems to homogeneity has a molecular mass of 64 kilodaltons (kD). Poly(A)+RNA was isolated from shoots of dwarf pea plants, and a cDNA library was constructed using lambda gt11 as an expression vector. The expression cDNA library was screened with polyclonal antibodies against pea cell wall invertase. One invertase cDNA clone was characterized as a full-length cDNA with 1,863 base pairs. Compared with other known invertases, one homologous region in the amino acid sequence was found. The conserved motif, Asn-Asp-Pro-Asn-Gly, is located near the N-terminal end of invertase. Northern blot analysis showed that the amount of invertase mRNA (1.86 kb) was rapidly induced to a maximal level 4 h after GA3 treatment, then gradually decreased to the control level. The mRNA level at 4 h in GA3-treated peas was fivefold higher than that of the control group. The maximal increase in activity of pea cell wall invertase elicited by GA3 occcured at 8 h after GA3 treatment. This invertase isoform was shown immunocytochemically to be localized in the cell walls, where a 10-fold higher accumulation occurred in GA3-treated tissue compared with control tissue. This study indicates that the expression of the pea shoot cell-wall invertase gene could be regulated by GA3 at transcriptional and/or translational levels.

NASA Discipline Number 40-50↗
NASA NTRS2005

Advanced Solar Cell Testing and Characterization

The topic for this workshop stems from an ongoing effort by the photovoltaic community and U.S. government to address issues and recent problems associated with solar cells and arrays experienced by a number of different space systems. In April 2003, a workshop session was held at the Aerospace Space Power Workshop to discuss an effort by the Air Force to update and standardize solar cell and array qualification test procedures in an effort to ameliorate some of these problems. The organizers of that workshop session thought it was important to continue these discussions and present this information to the entire photovoltaic community. Thus, it was decided to include this topic as a workshop at the following SPRAT conference.

Bailey, Sheila↗
NASA NTRS1984

Rodent CNS neuron development: Timing of cell birth and death

Data obtained from a staged series of single paired injections of tritiated thymidine to pregnant Wistar rats or C57B16/j mice on selected embryonic days and several postnatal times are reported. All injected specimens were allowed to come to term, each litter culled to six pups and specimens were sacrificed on PN28, with fixation and embedding for paraffin and plastic embedding. The results are derived from serial paraffin sections of PN28 animals exposed to autoradiographic processing and plotted with respect to heavily labelled cell nuclei present in the selected brain stem nuclei and sensory ganglia. Counts from each time sample/structure are totalled and the percentage of cells in the total labelled population/structure represented by each injection time interval plotted.

Keefe, J. R.↗
DOE OSTI2025

Emergence of lignin-carbohydrate interactions during plant stem maturation visualized by solid-state NMR

Lignification waterproofs and strengthens secondary plant cell walls but increases the energy cost of sugar release for biofuels. The physical association between lignin and the carbohydrate scaffold that accommodates lignin polymerization, along with the distinct roles of lignin units and carbohydrate partners during lignification, remain unclear. Here, we map lignin-carbohydrate spatial proximity by solid-state NMR in 13 C-labeled Arabidopsis inflorescence stems during secondary cell wall formation. Analyses include wild-type plants and mutants that selectively or globally disrupt lignin biosynthesis. Mature walls in basal regions show enrichment of S-lignin and dense carbohydrate-lignin packing. Acetylated xylan predominantly associates with S-lignin, while methylated pectin unexpectedly interacts with G-lignin during early-stage lignification. The importance of S-lignin in stabilizing the carbohydrate-lignin interface is highlighted by weak lignin-carbohydrate contacts and compromised mechanical properties in the low-S fah1 mutant, whereas the ref3 mutant, despite reduced lignin content, remains unaffected due to a high S/G ratio. Thus, molecular mixing patterns, rather than lignin content, critically determine the structure and properties of lignocellulosic materials.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1988

Direct and indirect pathways to lamina I in the medulla oblongata and spinal cord of the cat

The pathways to lamina I in the medulla oblongata and spinal cord of the cat were traced using horse-radish-peroxidase (HRP) and autoradiographic techniques. The HRP results indicated that several neuronal cell groups in the brain stem and hypothalamus project to the spinal cord throughout its total length. The autoradiographic tracing results demonstrated that the strongest projections to lamina I are derived from the following four areas: the caudal nucleus raphe magnus (NRM), the ventral part of the caudal pontine and NRM, the contralaterally projecting lateral pontine or paralemniscal tegmentum, and the paraventricular nucleus of the hypothalamus. In addition, a limited, especially at lumbosacral levels, distinct projection to lamina I was found to originate in the most caudal part of the medullary tegmentum.

Holstege, Gert↗
DOE OSTI2026

The structure, composition, and performance impact of a YSZ-GDC interdiffusion layer in solid oxide electrolysis cells

This study provides a combined experimental and computational investigation into the structure and impact of the cation interdiffusion layer that appears at the gadolinium doped ceria (GDC)/yttria stabilized zirconia (YSZ) interface in solid oxide electrolysis cells (SOECs). Scanning transmission electron microscopy (STEM) illustrates that a ∼0.4 μm interdiffusion layer (IDL) with an intermixed cation distribution and fine grain size forms upon sintering. STEM identifies that the interdiffusion layer exists in the cubic fluorite structure despite changes in cation composition. The interdiffusion layer microstructure formed during sintering does not change during SOEC testing at either 1.3V or heightened voltage pulse testing. Modeling predicts that ionic conductivity may decrease in the interdiffusion layer due to Coulombic trapping between mobile oxygen vacancies and excess Gd 3+ acceptor dopants. Yet, the density and continuous nature of the layer should benefit cell stability by substantially reducing the formation of SrZrO 3 , which is corroborated by STEM and Synchrotron X-ray diffraction (XRD). We conclude that the interdiffusion layer acts as a beneficial barrier to Sr diffusion, when operating in a regime where electrolyte void formation is not observed.

organic↗
NASA NTRS1992

Cellular distribution of calmodulin and calmodulin-binding proteins in Vicia faba L

The distribution of calmodulin (CaM) and CaM-binding proteins within Vicia faba was investigated. Both CaM and CaM-binding proteins were found to be differentially distributed among organs, tissues, and protoplast types. CaM levels, on a per protein basis, were found to be the highest in leaf epidermis, containing 3-fold higher levels of CaM than in total leaf. Similarly, guard cell and epidermal cell protoplasts were also found to have higher levels of CaM than mesophyll cell protoplasts. 125I-CaM blot overlay assays were performed to qualitatively examine CaM-binding proteins in these protoplast types as well as in whole tissues and organs. CaM-binding proteins with Mr 52,000, 78,000, and 115,000 were common in all metabolically active plant parts. Unique CaM-binding protein bands were detected in guard cell protoplasts (Mr 39,000, 88,000), stems (Mr 45,000, 60,000, 64,000), and roots (Mr 62,000), suggesting the presence of specialized CaM-dependent processes in these cells and organs.

Non-NASA Center↗
NASA NTRS2002

Total-body irradiation with high-LET particles: acute and chronic effects on the immune system

Although the immune system is highly susceptible to radiation-induced damage, consequences of high linear energy transfer (LET) radiation remain unclear. This study evaluated the effects of 0.1 gray (Gy), 0.5 Gy, and 2.0 Gy iron ion (56Fe(26)) radiation on lymphoid cells and organs of C57BL/6 mice on days 4 and 113 after whole body exposure; a group irradiated with 2.0 Gy silicon ions (28Si) was euthanized on day 113. On day 4 after 56Fe irradiation, dose-dependent decreases were noted in spleen and thymus masses and all major leukocyte populations in blood and spleen. The CD19(+) B lymphocytes were most radiosensitive and NK1.1(+) natural killer (NK) cells were most resistant. CD3(+) T cells were moderately radiosensitive and a greater loss of CD3(+)/CD8(+) T(C) cells than CD3(+)/CD4(+) T(H) cells was noted. Basal DNA synthesis was elevated on day 4, but response to mitogens and secretion of interleukin-2 and tumor necrosis factor-alpha were unaffected. Signs of anemia were noted. By day 113, high B cell numbers and low T(C) cell and monocyte percents were found in the 2.0 Gy 56Fe group; the 2.0 Gy 2)Si mice had low NK cells, decreased basal DNA synthesis, and a somewhat increased response to two mitogens. Collectively, the data show that lymphoid cells and tissues are markedly affected by high linear energy transfer (LET) radiation at relatively low doses, that some aberrations persist long after exposure, and that different consequences may be induced by various densely ionizing particles. Thus simultaneous exposure to multiple radiation sources could lead to a broader spectrum of immune dysfunction than currently anticipated.

NASA Discipline Radiation Health↗
NASA NTRS1980

Emergency/Night Lightning

UDEC's highly efficient lighting system is finding wide acceptance among industrial and commercial firms as an energy savings means of providing emergency and night lighting. Originating from Skylab, the system consists of small high frequency fluorescent light fixtures powered by solar cells. Advantages of UDEC's lighting system stem from high reliability and high light output with very low energy drain. Principal components of system are long life fluorescent lamps operated by electronic circuitry, a sealed gelatine cell battery that needs no maintenance for eight years and a solid-state automatic battery charger. Installation of UDEC lighting in a company's six-and-a-half acre warehouse office cut the annual night lighting electric bill from $8,000 a year to $300 per year.

Source record↗