Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “diffraction pattern”

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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Crystal structure of ponazuril, C 18 H 14 F 3 N 3 O 6 S

The crystal structure of ponazuril has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Ponazuril crystallizes in space group P2 1 /c (#14) with a = 8.49511(6), b = 12.38696(6), c = 18.84239(17) Å, β = 96.7166(4)°, V = 1969.152(12) Å 3 , and Z = 4. N–H∙∙∙O hydrogen bonds link the molecules into chains along the a-axis, with a graph set C1,1(6). The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2022

Crystal structure of nequinate, C 22 H 23 NO 4

The crystal structure of nequinate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Nequinate crystallizes in the space group P2 1 /c (#14) with a = 18.35662(20), b = 11.68784(6), c = 9.06122(4) Å, β = 99.3314(5)°, V = 1918.352(13) Å 3 , and Z = 4. The crystal structure is dominated by the stacking of the approximately planar molecules. N–H∙∙∙O hydrogen bonds link adjacent molecules into chains parallel to the b-axis. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2022

Powder X-ray diffraction of altrenogest, C 21 H 26 O 2

The crystal structure of altrenogest has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Altrenogest crystallizes in space group P2 1 2 1 2 1 (#19) with a = 7.286 916(16), b = 10.580 333(19), c = 22.266 08(7) Å, V = 1716.671(6) Å 3 , and Z = 4 at 295 K. Thermal expansion between 113 and 295 K is anisotropic. An O–H···O hydrogen bond links the molecules into chains along the c-axis. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of oxfendazole, C 15 H 13 N 3 O 3 S

The crystal structure of oxfendazole has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Oxfendazole crystallizes in space group P2 1 /c (#14) with a = 18.87326(26), b = 10.40333(5), c = 7.25089(5) Å, β = 91.4688(10)° V = 1423.206(10) Å 3 , and Z = 4. The crystal structure consists of stacks of the planar portions of the L-shaped molecules, resulting in layers parallel to the bc-plane. Only weak hydrogen bonds are present. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of deracoxib, C 17 H 14 F 3 N 3 O 3 S

The crystal structure of deracoxib has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Deracoxib crystallizes in space group Pbca (#61) with a = 9.68338(11), b = 9.50690(5), c = 38.2934(4) Å, V = 3525.25(3) Å 3 , and Z = 8. The molecules stack in layers parallel to the ab-plane. N–H∙∙∙O hydrogen bonds link the molecules along the b-axis, in chains with the graph set C1,1(4), as well as more-complex patterns. N–H∙∙∙N hydrogen bonds link the layers. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
NASA NTRS2006

Manufacturing Precise, Lightweight Paraboloidal Mirrors

A process for fabricating a precise, diffraction- limited, ultra-lightweight, composite- material (matrix/fiber) paraboloidal telescope mirror has been devised. Unlike the traditional process of fabrication of heavier glass-based mirrors, this process involves a minimum of manual steps and subjective judgment. Instead, this process involves objectively controllable, repeatable steps; hence, this process is better suited for mass production. Other processes that have been investigated for fabrication of precise composite-material lightweight mirrors have resulted in print-through of fiber patterns onto reflecting surfaces, and have not provided adequate structural support for maintenance of stable, diffraction-limited surface figures. In contrast, this process does not result in print-through of the fiber pattern onto the reflecting surface and does provide a lightweight, rigid structure capable of maintaining a diffraction-limited surface figure in the face of changing temperature, humidity, and air pressure. The process consists mainly of the following steps: 1. A precise glass mandrel is fabricated by conventional optical grinding and polishing. 2. The mandrel is coated with a release agent and covered with layers of a carbon- fiber composite material. 3. The outer surface of the outer layer of the carbon-fiber composite material is coated with a surfactant chosen to provide for the proper flow of an epoxy resin to be applied subsequently. 4. The mandrel as thus covered is mounted on a temperature-controlled spin table. 5. The table is heated to a suitable temperature and spun at a suitable speed as the epoxy resin is poured onto the coated carbon-fiber composite material. 6. The surface figure of the optic is monitored and adjusted by use of traditional Ronchi, Focault, and interferometric optical measurement techniques while the speed of rotation and the temperature are adjusted to obtain the desired figure. The proper selection of surfactant, speed or rotation, viscosity of the epoxy, and temperature make it possible to obtain the desired diffraction-limited, smooth (1/50th wave) parabolic outer surface, suitable for reflective coating. 7. A reflective coat is applied by use of conventional coating techniques. 8. Once the final figure is set, a lightweight structural foam is applied to the rear of the optic to ensure stability of the figure.

Hermann, Frederick Thomas↗
DOE OSTI2022

Crystal structure of imepitoin, C 13 H 14 ClN 3 O 2

The crystal structure of imepitoin has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Imepitoin crystallizes in space group Pbca (#61) with a = 12.35541(2), b = 28.43308(8), c = 7.340917(7) Å, V = 2578.882(7) Å 3 , and Z = 8. The roughly planar molecules stack along the c-axis. There are no traditional hydrogen bonds in the structure, but several intramolecular and intermolecular C–H∙∙∙O, C–H∙∙∙N, and C–H∙∙∙Cl hydrogen bonds contribute to the crystal energy. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2022

Crystal structure of diclazuril, C 17 H 9 Cl 3 N 4 O 2

The crystal structure of diclazuril has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Diclazuril crystallizes in space group P2 1 /a (#14) with a = 27.02080(18), b = 11.42308(8), c = 5.36978(5) Å, β = 91.7912(7)°, V = 1656.629(15) Å 3 , and Z = 4. The crystal structure consists of layers of molecules parallel to the ac-plane. A strong N–H∙∙∙O hydrogen bond links the molecules into dimers along the a-axis with a graph set R2,2(8). The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
NASA NTRS1985

Vector diffraction analysis of reflector antennas with mesh surfaces

Reflector antennas with mesh surfaces are used extensively in many satellite and ground antenna systems. A strip-aperture modeling of commonly used mesh surfaces is presented which provides considerable versatility in characterizing the mesh cells. The mesh transmission coefficients are constructed using a Floquet-modal expansion in conjuction with two dominant aperture modes. To account for the mesh local coordinates, the Eulerian angle transformation is invoked to obtain the total induced current on the curved reflector surface. General formulas are presented to show how the solid surface induced current is modified due to the transmission through the mesh. The effects of a variety of mesh configurations on both the co-polar and cross-polar patterns of reflector antennas are studied by numerically evaluating the vector diffraction integral using the Jacobi-Bessel expansion. For some special cases, a comparison is made with the results of the commonly used wire-grid formulation. Many of the numerical data are tailored to the dimensions of a conceptually designed mesh deployable offset reflector of the land mobile satellite system (LMSS).

Rahmat-Samii, Y.↗
DOE OSTI2022

Crystal structure of halofuginone hydrobromide, C 16 H 18 BrClN 3 O 3 Br

The crystal structure of one form of halofuginone hydrobromide has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Halofuginone hydrobromide crystallizes in space group P2 1 (#4) with a = 8.87398(13), b = 14.25711(20), c = 15.0153(3) Å, β = 91.6867(15)°, V = 1898.87(4) Å 3 , and Z = 4. The crystal structure consists of alternating layers (parallel to the ab-plane) of planar and nonplanar portions of the cations. N–H∙∙∙Br and O–H∙∙∙Br hydrogen bonds link the protonated piperidine rings and bromide anions into a two-dimensional network parallel to the ab-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of oxibendazole, C 12 H 15 N 3 O 3

The crystal structure of oxibendazole has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Oxibendazole crystallizes in space group C2/c (#15) with a = 23.18673(22), b = 5.35136(5), c = 19.88932(13) Å, β = 97.0876(9)°, V = 2449.018(17) Å 3 , and Z = 8. The structure consists of hydrogen-bonded layers of planar molecules parallel to the bc-plane. Strong N–H∙∙∙N hydrogen bonds link the molecules into dimers, with a graph set R2,2(8). N–H∙∙∙O hydrogen bonds further link these dimers into layers parallel to the bc-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of toceranib, C 22 H 25 FN 4 O 2

The crystal structure of toceranib has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Toceranib crystallizes in space group P2 1 /c (#14) with a = 10.6899(6), b = 24.5134(4), c = 7.8747(4) Å, β = 107.7737(13)°, V = 1965.04(3) Å 3 , and Z = 4. The crystal structure consists of stacks of approximately planar molecules, with N–H∙∙∙O hydrogen bonds between the layers. The commercial reagent sample was a mixture of two or more phases with toceranib being the dominant phase. The difference between the Rietveld-refined and DFT-optimized structures is larger than usual. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2024

Crystal structure of alectinib hydrochloride Type I, C 30 H 35 N 4 O 2 Cl

The crystal structure of alectinib hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Alectinib hydrochloride crystallizes in space groupP2 1 /n(#14) with the following parameters:a= 12.67477(7),b= 10.44076(5),c= 20.38501(12) Å,β= 93.1438(7)°,V= 2693.574(18) Å 3 , andZ= 4 at 295 K. The crystal structure consists of stacks of molecules along theb-axis, and the stacks contain chains of strong N–H⋯Cl hydrogen bonds. One density functional theory calculation moved a proton from an N atom to the Cl, but another calculation yielded a more chemically reasonable result. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®)

Materials Science↗
DOE OSTI2022

Crystal structure of haloxon, C 14 H 14 C l3 O 6 P

The crystal structure of haloxon has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Haloxon crystallizes in space group P2 1 /n (#14) with a = 19.60382(6), b = 10.05473(3), c = 8.73591(2) Å, β = 92.6617(2)°, V = 1720.088(11) Å 3 , and Z = 4. The structure consists of discrete molecules. The mean planes of the fused ring systems are approximately 0–11 and 011. The rings form staggered stacks perpendicular to these planes. There are no traditional hydrogen bonds in the structure, but several C–H∙∙∙O and C–H∙∙∙Cl hydrogen bonds contribute to the crystal energy. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystal structure of besifloxacin hydrochloride, C 19 H 22 ClFN 3 O 3 Cl

The crystal structure of besifloxacin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Besifloxacin hydrochloride crystallizes in space group P1 (#1) with a = 5.36596(8), b = 10.3234(4), c = 17.9673(14) Å, α = 98.122(5), β = 92.9395(9), γ = 96.1135(3)°, V = 977.483(13) Å 3 , and Z = 2. The crystal structure is approximately centrosymmetric. Strong N–H∙∙∙Cl hydrogen bonds form a corrugated ladder-like chain along the a-axis. The carboxylic acid group in each independent cation acts as the donor in a strong intramolecular O–H∙∙∙O hydrogen bond to an adjacent carbonyl group. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
DOE OSTI2022

Crystal structure of vismodegib, C 19 H 14 Cl 2 N 2 O 3 S

The crystal structure of vismodegib has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Vismodegib crystallizes in space group P2 1 /a (#14) with a = 16.92070(20), b = 10.20235(4), c = 12.16161(10) Å, β = 108.6802(3)°, V = 1988.873(9) Å 3 , and Z = 4. The crystal structure consists of corrugated layers of molecules parallel to the bc-plane. There is only one classical hydrogen bond in the structure, between the amide nitrogen atom and the N atom of the pyridine ring. Pairs of these hydrogen bonds link the molecules into dimers, with a graph set R2,2(14) > a > a. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

36 MATERIALS SCIENCE↗
NASA NTRS1974

Laser scattering induced holograms in lithium niobate

A 3.0-mm thick poled single crystal of lithium niobate doped with 0.1 mole% iron was exposed to a single beam and then to two intersecting beams of an argon ion laser operating at 515-nm wavelength. Laser scattering induced holograms were thus written and analyzed. The presence of diffraction cones was observed and is shown to result from the internally recorded interference pattern resulting from the interference of the original incident laser beam with light scattered from material inhomogeneities. This phenomenon is analyzed using Ewald sphere construction techniques which reveal the geometrical relationships existing for the diffraction cones.

Magnusson, R.↗