Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Cl2”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Cr(ClO2)3 by Materials Project

(CrO6)2(Cl2)3 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four chlorine molecules, four hydrochloric acid molecules, and four CrO6 clusters. In each CrO6 cluster, Cr is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are two shorter (2.01 Å) and two longer (2.05 Å) Cr–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a distorted L-shaped geometry to one Cr and one O atom. The O–O bond length is 1.39 Å. In the second O site, O is bonded in a water-like geometry to two O atoms. The O–O bond length is 1.36 Å. In the third O site, O is bonded in a distorted L-shaped geometry to one Cr and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge19(PCl)4 by Materials Project

Ge19P4(Cl2)2 crystallizes in the cubic P-43n space group. The structure is three-dimensional and consists of eight hydrochloric acid molecules and one Ge19P4 framework. In the Ge19P4 framework, there are three inequivalent Ge sites. In the first Ge site, Ge is bonded to three equivalent Ge and one P atom to form GeGe3P tetrahedra that share corners with three equivalent PGe4 tetrahedra and corners with nine GeGe3P tetrahedra. All Ge–Ge bond lengths are 2.45 Å. The Ge–P bond length is 2.38 Å. In the second Ge site, Ge is bonded to three Ge and one P atom to form GeGe3P tetrahedra that share corners with two equivalent PGe4 tetrahedra and corners with ten GeGe3P tetrahedra. There are one shorter (2.46 Å) and one longer (2.49 Å) Ge–Ge bond lengths. The Ge–P bond length is 2.41 Å. In the third Ge site, Ge is bonded to four equivalent Ge atoms to form GeGe4 tetrahedra that share corners with four equivalent PGe4 tetrahedra and corners with eight GeGe3P tetrahedra. P is bonded to four Ge atoms to form PGe4 tetrahedra that share corners with twelve GeGe3P tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaAl2Si4(ClO4)3 by Materials Project

(CaAl2Si4O12)2(Cl2)3 crystallizes in the monoclinic Cm space group. The structure is three-dimensional and consists of two chlorane molecules and one CaAl2Si4O12 framework. In the CaAl2Si4O12 framework, there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Ca–O bond distances ranging from 2.20–2.62 Å. In the second Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.97 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.83 Å. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.76 Å. There are four inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There is three shorter (1.63 Å) and one longer (1.64 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.57–1.68 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.70 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.71 Å. There are fourteen inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Ca and two Al atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and two Si atoms. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and two equivalent Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the eighth O site, O is bonded in a linear geometry to one Al and one Si atom. In the ninth O site, O is bonded in a linear geometry to two Si atoms. In the tenth O site, O is bonded in a linear geometry to one Al and one Si atom. In the eleventh O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the twelfth O site, O is bonded in a distorted trigonal non-coplanar geometry to one Ca and two equivalent Al atoms. In the thirteenth O site, O is bonded in a distorted trigonal planar geometry to one Ca and two Si atoms. In the fourteenth O site, O is bonded in a distorted trigonal planar geometry to one Ca and two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TiH42N14Cl3 by Materials Project

(Ti(NH3)8)2(NH3)12(Cl2)3 is Ammonia-derived structured and crystallizes in the monoclinic P2/c space group. The structure is zero-dimensional and consists of twelve ammonia molecules, six hydrochloric acid molecules, and two Ti(NH3)8 clusters. In each Ti(NH3)8 cluster, Ti3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are two shorter (2.29 Å) and six longer (2.30 Å) Ti–N bond lengths. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There are a spread of N–H bond distances ranging from 1.02–1.04 Å. In the second N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the fourth N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are twelve inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2H2CSe4Cl16O5 by Materials Project

Ti2OCl6CO2(HSeOCl2)2(SeCl)2(Cl2)2 crystallizes in the monoclinic P2/c space group. The structure is zero-dimensional and consists of two carbon dioxide molecules, four chlorine molecules, four chloroselenurane molecules, two HSeOCl2 clusters, and two Ti2OCl6 clusters. In each HSeOCl2 cluster, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. Se3+ is bonded in a distorted L-shaped geometry to one O2- and one Cl1- atom. The Se–O bond length is 1.81 Å. The Se–Cl bond length is 2.39 Å. O2- is bonded in a distorted water-like geometry to one H1+ and one Se3+ atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted linear geometry to two Cl1- atoms. There are one shorter (2.08 Å) and one longer (2.92 Å) Cl–Cl bond lengths. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Se3+ and one Cl1- atom. In each Ti2OCl6 cluster, Ti4+ is bonded to one O2- and three Cl1- atoms to form corner-sharing TiCl3O tetrahedra. The Ti–O bond length is 1.79 Å. There are two shorter (2.19 Å) and one longer (2.21 Å) Ti–Cl bond lengths. O2- is bonded in a linear geometry to two equivalent Ti4+ atoms. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Ti4+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Ti4+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Ti4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb3(Cl3O4)2 by Materials Project

(Nb3O7)2O2(Cl2)6 crystallizes in the cubic Fm-3m space group. The structure is zero-dimensional and consists of twenty-four chlorine molecules, eight water molecules, and four Nb3O7 clusters. In each Nb3O7 cluster, Nb is bonded in a 5-coordinate geometry to five O atoms. There is one shorter (1.73 Å) and four longer (2.10 Å) Nb–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Nb atom. In the second O site, O is bonded in a distorted trigonal non-coplanar geometry to three equivalent Nb atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Replacing Pyridine with Pyrazine in Molecular Cobalt Catalysts: Effects on Electrochemical Properties and Aqueous H2 Generation

Four new molecular Co(II)tetrapyridyl complexes were synthesized and evaluated for their activity as catalysts for proton reduction in aqueous environments. The pyridine groups around the macrocycle were substituted for either one or two pyrazine groups. Single crystal X-ray analysis shows that the pyrazine groups have minimal impact on the Co(II)–N bond lengths and molecular geometry in general. X-band EPR spectroscopy confirms the Co(II) oxidation state and the electronic environment of the Co(II) center are only very slightly perturbed by the substitution of pyrazine groups around the macrocycle. The substitution of pyrazine groups has a substantial impact on the observed metal- and ligand-centered reduction potentials as well as the overall H2 catalytic activity in a multimolecular system using the [Ru(2,2′-bipyridine)3]Cl2 photosensitizer and ascorbic acid as a sacrificial electron donor. The results reveal interesting trends between the H2 catalytic activity for each catalyst and the driving force for electron transfer between either the reduced photosensitizer to catalyst step or the catalyst to proton reduction step. The work presented here showcases how even the difference of a single atom in a molecular catalyst can have an important impact on activity and suggests a pathway to optimize the photocatalytic activity and stability of molecular systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Observation of a New Polyhalide Phase in Ag-Cl 2 System at High Pressure

In this short contribution, we examine Raman spectroscopic data from high-pressure and high-temperature experiments with an Ag-Cl2 system, and find that they are in good agreement with previously observed and calculated spectra of polychloride species. Our results imply the formation of a hitherto unknown AgClx compound, which warrants further study.

36 MATERIALS SCIENCE↗
NASA NTRS1971

Research and investigation of gas dynamic lasers

Chemical mixing laser investigations were conducted (1) to investigate the properties of a bimolecular exchange laser system pumped by the H + Cl2 yields HCl(v) + Cl reaction, initiated by arc-dissociated H2, with lasing occurring between wavelengths of 3.4 and 4.0 microns, and (2) to establish the feasibility of an atom recombination-transfer laser employing recombination of arc-dissociated nitrogen with subsequent transfer of vibrational energy to CO2 for lasing at 10.6 microns. One-dimensional analytical results indicate higher results should be obtained with up to v = 3 to 2 transitions participating. Diagnostic and analytical results show that the reaction mechanism during mixing, a back reaction of HCl(v) with H atoms, reaction of Cl with H2(v), moderately fast V-V, V-T processes, and possible HCl(o) initial contaminant level may explain the low performance. N2-CO2 thermal mixing laser studies were extended to measure the efficiency of transfer of recombination energy in such a nonequilibrium N2 source to 10.6 microns optical energy. The low level of efficiency suggests that V-T decay processes may prevent vibrational energy freezing until much lower temperatures are achieved and that trapping of energy in long-lived electronic excitation of N2 may be a factor.

Boedeker, L. R.↗
NASA NTRS1972

Rechargeable Al/Cl2 battery with molten AlCl4/-/ electrolyte.

A molten salt system based on Al- and Cl2 carbon electrodes, with an AlCl3 alkali chloride eutectic as electrolyte, offers promise as a rechargeable, high energy density battery which can operate at a relatively low temperature. Electrode kinetic studies showed that the electrode reactions at the Al anode were rapid and that the observed passivation phenomena were due to the formation at the electrode surface of a solid salt layer resulting from concentration changes on anodic or cathodic current flow. It was established that carbon electrodes were intrinsically active for chlorine reduction in AlCl3-alkali chloride melts. By means of a rotating vitreous carbon disk electrode, the kinetic parameters were determined.

Holleck, G. L.↗
NASA NTRS1972

Toxic Hazards Research Unit annual technical report, 1972

The activities of the Toxic Hazards Research Unit (THRU) for the period of June 1971 through May 1972 are reviewed in this report. Acute inhalation toxicity experiments were conducted on hydrogen chloride (HCl) gas and aerosol, ethyl bromide (C2H5Br), hydrogen bromide (HBr), hydrogen sulfide (H2S), ammonia (NH3), chlorine (CL2), and silane (SiH4). Subacute toxicity studies were conducted on chlorine pentafluoride (ClF5), dichloromethane (CH2Cl2) and coal tar volatiles. Further toxicity studies of subacute and chronic responses to inhaled monomethylhydrazine (MMH) are also described.

Macewen, J. D.↗
NASA NTRS1974

Sliding of poly(vinyl chloride) on metals studied by Auger electron spectroscopy

The sliding of polyvinyl chloride on nickel, iron and S-Monel has been studied by Auger electron spectroscopy. Polymer was not transferred to the metals, rather shear appeared to take place at the interface. The metal was progressively chlorinated as the polymer made multiple passes on the surface. The thickness of this chlorine film was the order of one atomic layer. Electron-induced desorption studies indicate that the chlorine is chemisorbed to the metal. These results are interpreted as evidence for mechanically induced and/or thermal degradation of the polymer during sliding. Degradation products of HCl and Cl2 which chemisorb to the metal are evolved near the interface.

Pepper, S. V.↗
NASA NTRS1973

Development of an iodine generator for reclaimed water purification in manned spacecraft applications

A successful 30-day test is described of a prototype Iodine Generating and Dispensing System (IGDS). The IGDS was sized to iodinate the drinking water nominally consumed by six men, 4.5 to 13.6 kg (10 to 30 lb) water per man-day with a + or - 10 to 20% variation with iodine (I2) levels of 0.5 to 20 parts per million (ppm). The I2 treats reclaimed water to prevent or eliminate microorganism contamination. Treatment is maintained with a residual of I2 within the manned spacecraft water supply. A simplified version of the chlorogen water disinfection concept, developed by life systems for on-site generation of chlorine (Cl2), was used as a basis for IGDS development. Potable water contaminated with abundant E. Coliform Group organisms was treated by electrolytically generated I2 at levels of 5 to 10 ppm. In all instances, the E. coli were eliminated.

Wynveen, R. A.↗
NASA NTRS1975

Estimate of late 1974 stratospheric concentration of gaseous chlorine compounds /ClX/

The total concentration (ClX) versus altitude of Cl-containing molecules (principally HCl, Cl, ClO) is estimated. It is shown that the predicted present stratospheric concentrations are due to photolysis near 30 km of man-made CF2Cl2 and CFCl3, and CCl4 from a ground-level source, either man-made or natural. The contribution of CH3Cl to stratospheric ClX is evaluated from preliminary measurements of the compound at ground level. Although ground-level sources of HCl and Cl2 are large, tropospheric processes preclude significant impact on the stratosphere.

Cicerone, R. J.↗
NASA NTRS1975

Low cost processes for solar-grade silicon

Upgrading metallurgical grade silicon is being pursued in four associated areas in order to improve the purity of the normally 98% material. The first two work areas involve purification of raw materials entering the process in addition to upgrading the arc furnace itself. The second two areas of process upgrading comprise improving the purity of the silicon after it leaves the arc furnace by reactive gas blowing and unidirectional freezing. The best cell produced to date was fabricated from MG-Si that had been blown with an O2-Cl2 mixture, unidirectionally solidified, and 6-float-zone passed (to determine a base boron level of 0.04 ohm/cm). The cell showed a 10.7% AMO efficiency. In the other processes category, the use of silicates as a silicon source and of electrolysis as a process were studied. The best electrolytic process uses a 1000 C fused salt of silica in cryolite.

Hunt, L. P.↗
NASA NTRS1975

Epitaxial solar cells fabrication

Silicon epitaxy has been studied for the fabrication of solar cell structures, with the intent of optimizing efficiency while maintaining suitability for space applications. SiH2CL2 yielded good quality layers and junctions with reproducible impurity profiles. Diode characteristics and lifetimes in the epitaxial layers were investigated as a function of epitaxial growth conditions and doping profile, as was the effect of substrates and epitaxial post-gettering on lifetime. The pyrolytic decomposition of SiH4 was also used in the epitaxial formation of highly doped junction layers on bulk Si wafers. The effects of junction layer thickness and bulk background doping level on cell performance, in particular, open-circuit voltage, were investigated. The most successful solar cells were fabricated with SiH2 CL2 to grow p/n layers on n(+) substrates. The best performance was obtained from a p(+)/p/n/n(+) structure grown with an exponential grade in the n-base layer.

Daiello, R. V.↗
NASA NTRS1976

Shear strength of metal-sapphire contacts

The shear strength of polycrystalline Ag, Cu, Ni, and Fe contacts on clean (0001) sapphire has been studied in ultrahigh vacuum. Both clean metal surfaces and surfaces exposed to O2, Cl2, and C2H4 were used. The results indicate that there are two sources of strength of Al2O3-metal contacts: an intrinsic one that depends on the particular clean metal in contact with Al2O3 and an additional one due to intermediate films. The shear strength of the clean metal contacts correlated directly with the free energy of oxide formation for the lowest metal oxide, in accord with the hypothesis that a chemical bond is formed between metal cations and oxygen anions in the sapphire surface. Contacts formed by metals exposed to chlorine exhibited uniformly low shear strength indicative of van der Waals bonding between chlorinated metal surfaces and sapphire. Contacts formed by metals exposed to oxygen exhibited enhanced shear strength, in accord with the hypothesis that an intermediate oxide layer increases interfacial strength.

Pepper, S. V.↗