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CK2 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to four equivalent C2- atoms to form a mixture of corner and edge-sharing KC4 tetrahedra. All K–C bond lengths are 3.12 Å. C2- is bonded in a body-centered cubic geometry to eight equivalent K1+ atoms.
K2Pt is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to four equivalent Pt2- atoms to form a mixture of corner and edge-sharing KPt4 tetrahedra. All K–Pt bond lengths are 3.32 Å. Pt2- is bonded in a body-centered cubic geometry to eight equivalent K1+ atoms.
A seminumerical method is presented for three-dimensional elastic analysis of finite geometry solids with traction-free cracks. Stress and displacement distributions are calculated for two rectangular bars which are loaded by a uniform surface stress distribution. The first bar contains a through-thickness central crack while the second bar has double-edge cracks. Stress intensity factors K sub I for both configurations are presented.
A crystal spectrometer system is described which employs conical focusing of 12 curved LiF crystal panels to minimize the detector size and reduce the background counting rate. The wavelength range from 1.70 to 1.98 A is covered, including the resonance lines of Fe XXV and Fe XXVI as well as the Fe I K-alpha line and absorption edge. Operation of the spectrometer is discussed, noting that diffracted X-rays are registered in one-dimensional position-sensitive detectors and that the arrival position of a photon in a detector is related to its wavelength due to the fixed curvature of the crystal panels in the dispersion plane. Some characteristics of the multianode position-sensitive detectors are reviewed along with the crystal arrangement and mounting. The instrument sensitivity is evaluated in relation to the strengths of 6.7-keV emission features detected by the Ariel 5 and OSO 8 proportional-counter spectrometers.
Mapping of the dark cloud L 134 N in (C-12)O and (C-13)O has shown that at least two subclouds are distinguishable spatially and in velocity. (C-12)O emission is distributed over an area of about 90 arcmin diameter with a maximum temperature of about 11 K; for (C-13)O these are about 50 arcmin and 4 K. Linewidths increase from the edge of the cloud inward to a peak of about 2.5 km/s at the position of the (C-13)O temperature maximum. Line velocities show much variation as a function of position, but the predominant emission component occurs at 2.5-3 km/s in the LSR frame. Comparisons are made with earlier observations of L 134 N and with recent observations of L 134.
The results of a program of observations of the cataclysmic variable V442 Oph from UV to IR wavelengths are reported. The observations comprise IUE SWP and LWR-camera spectra from October, 1981; UBVr and R photometry at Manastash Ridge Observatory from August, 1980; UBV photometry and IR measurements at Kitt Peak from July, 1981; and Coudespectroscopy at Mt. Wilson from June, 1980, and at Mt Lemmon from July, 1982. Tables of data, plots of H-alpha and He-II radial velocity, sample spectra, light curves, and a log-log diagram of F(lambda) vs lambda are given. Flux-ratio analysis of the IR data indicates a disk with very little optically thin material anad an outer-edge temperature of about 7920 K. The calculated period (3.37 h) and mass-accretion rate (1 x 10 to the -8th solar mass/yr) are compared to those of similar objects, and V442 Oph is found to be similar in this respect to systems like H2252-035. Its lack of a rotational period and the weakness of the optical and UV line emissions, however, are more like the old nova V603 Aql.
Engine LH2 and LO2 gas generator feed assemblies were modeled with computational fluid dynamics (CFD) methods at 100% rated power level, using on-center square- and round-edge orifices. The purpose of the orifices is to regulate the flow of fuel and oxidizer to the gas generator, enabling optimal power supply to the turbine and pump assemblies. The unsteady Reynolds-Averaged Navier-Stokes equations were solved on unstructured grids at second-order spatial and temporal accuracy. The LO2 model was validated against published experimental data and semi-empirical relationships for thin-plate orifices over a range of Reynolds numbers. Predictions for the LO2 square- and round-edge orifices precisely match experiment and semi-empirical formulas, despite complex feedline geometry whereby a portion of the flow from the engine main feedlines travels at a right-angle through a smaller-diameter pipe containing the orifice. Predictions for LH2 square- and round-edge orifice designs match experiment and semi-empirical formulas to varying degrees depending on the semi-empirical formula being evaluated. LO2 mass flow rate through the square-edge orifice is predicted to be 25 percent less than the flow rate budgeted in the original engine balance, which was subsequently modified. LH2 mass flow rate through the square-edge orifice is predicted to be 5 percent greater than the flow rate budgeted in the engine balance. Since CFD predictions for LO2 and LH2 square-edge orifice pressure loss coefficients, K, both agree with published data, the equation for K has been used to define a procedure for orifice sizing.
K2Zn(CN)4 crystallizes in the trigonal R-3c space group. The structure is three-dimensional and consists of one K(CN)2 framework and twelve zinc molecules. In the K(CN)2 framework, there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six N3- atoms to form distorted edge-sharing KN6 pentagonal pyramids. There are a spread of K–N bond distances ranging from 2.87–3.02 Å. In the second K1+ site, K1+ is bonded to six equivalent N3- atoms to form edge-sharing KN6 octahedra. All K–N bond lengths are 2.86 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.17 Å. In the second C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.17 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 1-coordinate geometry to three K1+ and one C2+ atom. In the second N3- site, N3- is bonded to three equivalent K1+ and one C2+ atom to form distorted corner-sharing NK3C tetrahedra.
Using a new 2D radiative transfer algorithm, we have calculated the thermally reradiated infrared spectra of the compact dust tori which are thought to surround many AGN. These tori radiate anisotropically. Face-on tori may be from one-half to a few orders of magnitude brighter than edge-on tori throughout the infrared. Their spectra at nearly all viewing angles are basically 'bumps' which are about 50 percent wider than blackbodies and peak in the mid-infrared at a wavelength determined mainly by the flux of nuclear radiation on the inner edge of the torus. The infrared color temperatures are hotter for face-on tori than edge-on tori by about 100 K. The 10 micron silicate feature often associated with dust can appear in absorption, emission, or not at all. There is a rough tendency for absorption features to be more prominent for edge-on tori than for face-on tori.
KPF6 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent F1- atoms to form KF12 cuboctahedra that share edges with six equivalent KF12 cuboctahedra and edges with six equivalent PF6 octahedra. All K–F bond lengths are 3.09 Å. P5+ is bonded to six equivalent F1- atoms to form PF6 octahedra that share edges with six equivalent KF12 cuboctahedra. All P–F bond lengths are 1.64 Å. F1- is bonded in a single-bond geometry to two equivalent K1+ and one P5+ atom.
K3Bi is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Bi atoms to form a mixture of distorted edge, face, and corner-sharing KK4Bi4 tetrahedra. All K–K bond lengths are 3.78 Å. All K–Bi bond lengths are 3.78 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Bi is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K is Magnesium structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K is bonded to twelve equivalent K atoms to form a mixture of distorted corner, edge, and face-sharing KK12 cuboctahedra. There are a spread of K–K bond distances ranging from 4.65–4.79 Å.
K3Zr is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Zr atoms to form a mixture of distorted edge, corner, and face-sharing KK4Zr4 tetrahedra. All K–K bond lengths are 4.04 Å. All K–Zr bond lengths are 4.04 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Zr is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K3Mo is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Mo atoms to form a mixture of distorted edge, face, and corner-sharing KK4Mo4 tetrahedra. All K–K bond lengths are 4.00 Å. All K–Mo bond lengths are 4.00 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Mo is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K3Ge is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Ge atoms to form a mixture of distorted edge, face, and corner-sharing KK4Ge4 tetrahedra. All K–K bond lengths are 3.73 Å. All K–Ge bond lengths are 3.73 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Ge is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K3Re is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Re atoms to form a mixture of distorted edge, face, and corner-sharing KK4Re4 tetrahedra. All K–K bond lengths are 3.82 Å. All K–Re bond lengths are 3.82 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Re is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K3Ta is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Ta atoms to form a mixture of distorted edge, corner, and face-sharing KK4Ta4 tetrahedra. All K–K bond lengths are 3.90 Å. All K–Ta bond lengths are 3.90 Å. In the second K site, K is bonded in a distorted body-centered cubic geometry to eight equivalent K atoms. Ta is bonded in a body-centered cubic geometry to eight equivalent K atoms.
K3Os is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Os atoms to form a mixture of distorted edge, corner, and face-sharing KK4Os4 tetrahedra. All K–K bond lengths are 3.59 Å. All K–Os bond lengths are 3.59 Å. In the second K site, K is bonded in a 10-coordinate geometry to eight equivalent K and two equivalent Os atoms. Both K–Os bond lengths are 4.00 Å. Os is bonded in a distorted body-centered cubic geometry to ten K atoms.