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Results for “ETHYLENE COMPOUND”

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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Development of flame and smoke retardant thermoplastic molding compounds

Compositions of polypropylene and ethylene-acrylic acid resins filled with high levels of alumina trihydrate of magnesium hydroxide were examined for smoke generation and impact resistance. Best results were obtained using alumina trihydrate coated with a low modulus elastomer, and ethylene-acrylic acid resin. Addition of polyvinyl alcohol fibers to the filled resin improves impact resistance and causes somewhat of an increase in smoke evolution.

Mueller, W. A.↗
DOE OSTI2023

Wounding rapidly alters transcription factor expression, hormonal signaling, and phenolic compound metabolism in harvested sugarbeet roots

Injuries sustained by sugarbeet (Beta vulgaris L.) roots during harvest and postharvest operations seriously reduce the yield of white sugar produced from stored roots. Although wound healing is critically important to reduce losses, knowledge of these processes is limited for this crop as well as for roots in other species. To better understand the metabolic signals and changes that occur in wounded roots, dynamic changes in gene expression were determined by RNA sequencing and the activity of products from key genes identified in this analysis were determined in the 0.25 to 24 h following injury. Nearly five thousand differentially expressed genes that contribute to a wide range of cellular and molecular functions were identified in wounded roots. Highly upregulated genes included transcription factor genes, as well as genes involved in ethylene and jasmonic acid (JA) biosynthesis and signaling and phenolic compound biosynthesis and polymerization. Enzyme activities for key genes in ethylene and phenolic compound biosynthesis and polymerization also increased due to wounding. Results indicate that wounding causes a major reallocation of metabolism in sugarbeet taproots. Although both ethylene and JA are likely involved in triggering wound responses, the greater and more sustained upregulation of ethylene biosynthesis and signaling genes relative to those of JA, suggest a preeminence of ethylene signaling in wounded sugarbeet roots. Changes in gene expression and enzymes involved in phenolic compound metabolism additionally indicate that barriers synthesized to seal off wounds, such as suberin or lignin, are initiated within the first 24 h after injury.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1979

Hydrogen atom initiated chemistry

H Atoms have been created by the photolysis of H2S. These then initiated reactions in mixtures involving acetylene-ammonia-water and ethylene-ammonia-water. In the case of the acetylene system, the products consisted of two amino acids, ethylene and a group of primarily cyclic thio-compounds, but no free sulfur. In the case of the ethylene systems, seven amino acids, including an aromatic one, ethane, free sulfur, and a group of solely linear thio-compounds were produced. Total quantum yields for the production of amino acids were about 3 x 10 to the -5th and about 2 x 10 to the -4th with ethylene and acetylene respectively as carbon substrates. Consideration is given of the mechanism for the formation of some of the products and implications regarding planetary atmosphere chemistry, particularly that of Jupiter, are explored.

Hong, J. H.↗
DOE OSTI2025

Numerical simulation for the design of induction heating based radio frequency reactor for ethylene production

Ethylene is a vital petrochemical compound produced in vast amounts yearly by manufacturers that have enough scale to overcome the inherent thermodynamic inefficiencies of the process. In order to address the inefficiencies that prevent smaller scale or intermittent production ethylene, investigation of new production methods are required. In this work, we investigate the use of a radio frequency (RF) based reactor system that generates heat internally as opposed to applying heat externally via steam or direct combustion of fossil fuels. In order to guide the design of an electromagnetic based reactor system, we have created a macroscale model capable of capturing heat generation at the susceptors from a produced electromagnetic field and subsequent chemical reactions. Several susceptor and induction coil designs were investigated to better understand the performance of the system.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1996

NASA's Biomass Production Chamber: a testbed for bioregenerative life support studies

The Biomass Production Chamber (BPC) located at Kennedy Space Center, FL, USA provides a large (20 m2 area, 113 m3 vol.), closed environment for crop growth tests for NASA's Controlled Ecological Life Support System (CELSS) program. Since the summer of 1988, the chamber has operated on a near-continuous basis (over 1200 days) without any major failures (excluding temporary power losses). During this time, five crops of wheat (64-86 days each), three crops of soybean (90 to 97 days), five crops of lettuce (28-30 days), and four crops of potato (90 to 105 days were grown, producing 481 kg of dry plant biomass, 196 kg edible biomass, 540 kg of oxygen, 94,700 kg of condensed water, and fixing 739 kg of carbon dioxide. Results indicate that total biomass yields were close to expected values for the given light input, but edible biomass yields and harvest indices were slightly lower than expected. Stand photosynthesis, respiration, transpiration, and nutrient uptake rates were monitored throughout growth and development of the different crops, along with the build-up of ethylene and other volatile organic compounds in the atmosphere. Data were also gathered on system hardware maintenance and repair, as well as person-hours required for chamber operation. Future tests will include long-term crop production studies, tests in which nutrients from waste treatment systems will be used to grow new crops, and multi-species tests.

NASA Center KSC↗
NASA NTRS2016

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED lighting, and those capabilities continue to expand. The 'Veggie' vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nm), blue, (455 nm) and green (530 nm) LEDs. Interfacing with the light cap is an extendable bellows/baseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Advanced Plant Habitat↗
NASA NTRS2016

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Veggie↗
DOE OSTI2022

Two Distinct Cu(II)-V(IV) Superexchange Interactions with Similar Bond Angles in a Triangular ?CuV2? Fragment

The strength and sign of superexchange interactions are often predicted on the basis of the bond angles between magnetic ions, but complications may arise in situations with a nontrivial arrangement of the magnetic orbitals. We report on a novel molecular tetramer compound [Cu(H2O)dmbpy]2[V2O2F8] (dmbpy = 4,4 '-dimethyl-2,2 ' bipyridyl) that is composed of triangular "CuV2" fragments and displays a spin gap behavior. By combining first-principles calculations and electronic models, we reveal that superexchange Cu-V interactions carry drastically diHerent coupling strengths along two Cu-F-V pathways with comparable bond angles in the triangular "CuV2" fragment. Counterintuitively, their strong disparity is found to originate from the restricted symmetry of the half-filled Cu dx2-y2 orbital stabilized by the crystal field, leading to one dominating antiferromagnetic Cu-V coupling in each fragment. We revisit the magnetic properties of the reported spin-gapped chain compound [enH2]Cu(H2O)2[V2O2F8] (enH2 = ethylene diammonium) containing similar triangular "CuV2" fragments, and the magnetic behavior of the molecular tetramer and the chain compounds is rationalized as that of weakly coupled spin dimers and spin trimers, respectively. This work demonstrates that fundamentally diHerent magnetic couplings can be observed between magnetic ions with similar bond angles in a single spin motif, thus providing a strategy to introduce various exchange interactions combined with low dimensionality in heterometallic Cu(II)-V(IV) compounds.

Complexes↗
NASA NTRS1982

Atmospheric chemistry of ethane and ethylene

It is shown by a study of ethane and ethylene photochemistry that the loss of ethane is controlled by OH in the troposphere and Cl in the stratosphere. Ethane observations indicating free Cl concentrations below 30 km that are only 10% of the value predicted by the present model calculations cannot be explained by heterogeneous aerosol concentration processes, and contradict current stratospheric photochemistry. The chemical destruction of ethane and ethylene leads to the generation of such compounds as carbon monoxide and formaldehyde, and it is found that the tropospheric concentrations of the latter are enhanced by nearly a factor of three for an ethylene mixing ratio of 2 ppb.

Aikin, A. C.↗
NASA NTRS1970

Colorometric detection of ethylene glycol vapor

Very low concentrations of ethylene glycol in air or other gases are detected by passing a sample through a glass tube with three partitioned compartments containing reagents which successively convert the ethylene glycol vapor into a colored compound.

Helm, C.↗
NASA NTRS1988

Gaseous emissions from plants in controlled environments

Plant growth in a controlled ecological life support system may entail the build-up over extended time periods of phytotoxic concentrations of volatile organic compounds produced by the plants themselves. Ethylene is a prominent gaseous emission of plants, and is the focus of this report. The objective was to determine the rate of ethylene release by spring wheat, white potato, and lettuce during early, middle, and late growth stages, and during both the light and dark segments of the diurnal cycle. Plants grown hydroponically using the nutrient film technique were covered with plexiglass containers for 4 to 6 h. At intervals after enclosure, gas samples were withdrawn with a syringe and analyzed for ethylene with a gas chromatograph. Lettuce produced 10 to 100 times more ethylene than wheat or potato, with production rates ranging from 141 to 158 ng g-dry/wt/h. Wheat produced from 1.7 to 14.3 ng g-dry/wt/h, with senescent wheat producing the least amount and flowering wheat the most. Potatoes produced the least amount of ethylene, with values never exceeding 5 ng g-dry/wt/h. Lettuce and potatoes each produced ethylene at similar rates whether in dark period or light period. Ethylene sequestering of 33 to 43 percent by the plexiglass enclosures indicated that these production estimates may be low by one-third to one-half. These results suggest that concern for ethylene build-up in a contained atmosphere should be greatest when growing lettuce, and less when growing wheat or potato.

Dubay, Denis T.↗
DOE OSTI2023

Diversification of JAZ‐MYC signaling function in immune metabolism

Summary Jasmonate (JA) re‐programs metabolism to confer resistance to diverse environmental threats. Jasmonate stimulates the degradation of JASMONATE ZIM‐DOMAIN (JAZ) proteins that repress the activity of MYC transcription factors. In Arabidopsis thaliana , MYC and JAZ are encoded by 4 and 13 genes, respectively. The extent to which expansion of the MYC and JAZ families has contributed to functional diversification of JA responses is not well understood. Here, we investigated the role of MYC and JAZ paralogs in controlling the production of defense compounds derived from aromatic amino acids (AAAs). Analysis of loss‐of‐function and dominant myc mutations identified MYC3 and MYC4 as the major regulators of JA‐induced tryptophan metabolism. We developed a JAZ family‐based, forward genetics approach to screen randomized jaz polymutants for allelic combinations that enhance tryptophan biosynthetic capacity. We found that mutants defective in all members ( JAZ1/2/5/6 ) of JAZ group I over‐accumulate AAA‐derived defense compounds, constitutively express marker genes for the JA–ethylene branch of immunity and are more resistant to necrotrophic pathogens but not insect herbivores. In defining JAZ and MYC paralogs that regulate the production of amino‐acid‐derived defense compounds, our results provide insight into the specificity of JA signaling in immunity.

jasmonate↗
NASA NTRS2006

Thermal Conductivity of Polymer/Nano-filler Blends

To improve the thermal conductivity of an ethylene vinyl acetate copolymer, Elvax 260 was compounded with three carbon based nano-fillers. Multiwalled carbon nanotubes (MWCNT), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. In an attempt to improve compatibility between the Elvax and nanofillers, MWCNTs and EGs were modified through non covalent and covalent attachment of alkyl groups. Ribbons were extruded to form samples in which the nanofillers were aligned, and samples were also fabricated by compression molding in which the nano-fillers were randomly oriented. The thermal properties were evaluated by DSC and TGA, and mechanical properties of the aligned samples were determined by tensile testing. The degree of dispersion and alignment of the nanoparticles were investigated using high-resolution scanning electron microscopy. Thermal conductivity measurements were performed using a Nanoflash technique. The thermal conductivity of the samples was measured in both the direction of alignment as well as perpendicular to that direction. The results of this study will be presented.

Ghose, Sayata↗
DOE OSTI2023

Direct catalytic conversion of alcohols to olefins of higher carbon number with reduced ethylene production

A catalyst composition for converting an alcohol to olefins, the catalyst composition comprising the following components: (a) a support (e.g., particles) comprising silicon and oxygen; (b) at least one of copper and silver residing on and/or incorporated into said support; and (c) at least one lanthanide element residing on and/or incorporated into said support. The catalyst may also further include component (d), which is zinc. Also described herein is a method for converting an alcohol to one or more olefinic compounds (an olefin fraction) by contacting the alcohol with a catalyst at a temperature of at least 100° C. and up to 500° C. to result in direct conversion of the alcohol to an olefin fraction containing one or more olefinic compounds containing at least three carbon atoms; wherein ethylene and propylene are produced in a minor proportion of the olefin fraction, and butenes and higher olefins are produced in major proportion.

Li, Zhenglong↗
NASA NTRS1973

Rubber compositions for hydrazine service

Forty-three compounds were formulated and tested for physical properties and hydrazine compatibility. Variables introduced include silicon dioxide filler loading level and particle size. Both butyl and ethylene-propylene rubbers were employed as well as various vulcanization systems. The data showed that compounds containing butyl and butyl blended with ethylene propylene could not be distinguished from ethylene propylene alone as far as chemical properties were concerned. A trend noted was that a filler level with higher silicon dioxide loading exhibited better hydrazine compatibility. Particle size variation did not show any consistent trends. Any of the vulcanization systems employed appeared to be satisfactory. A refined technique for dissolving aluminum cores from EPT-10 bladders was also tested.

Repar, J.↗
DOE OSTI2026

Novel insight into the kinetics of amide bond glycolysis for nylon-6 depolymerization

Chemical recycling of nylon-6 to short-chain oligomers and monomer ε-caprolactam via catalytic glycolysis is a potential solution for plastic waste remediation. Here, in this work, the kinetics of amide bond glycolysis (with ethylene glycol) in nylon-6 and the model compound N-phenethyl-3-phenylpropanamide (M1) were evaluated at 473 K in the presence of the cyclic amidine catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene. Rates of polymer glycolysis were determined by the time-dependent shift in molecular weight distribution, whereas rates of M1 glycolysis were determined using liquid chromatography. The similarity of the first-order rate constants for glycolysis of nylon-6 and M1 at 473 K with 0.03 M amidine catalyst (5 mol% relative to amide bonds), 1.22 × 10 −5 s −1 and 2.18 × 10 −5 s −1 , respectively, confirmed the suitability of M1 as a model compound for nylon-6 glycolysis. Similar rates of glycolysis in the presence of other cyclic amidine catalysts as well as sodium methoxide revealed little influence of base strength. Glycolysis rates were unexpectedly non-linear in catalyst loading and deactivation occurred with long reaction times, presumably by non-selective decomposition of products as detected by liquid chromatography.

Depolymerization rate and rate constant↗