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At least 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Li3ClO by Materials Project

Li3OCl is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Li1+ is bonded in a distorted linear geometry to two equivalent O2- and four equivalent Cl1- atoms. Both Li–O bond lengths are 1.95 Å. All Li–Cl bond lengths are 2.76 Å. O2- is bonded to six equivalent Li1+ atoms to form OLi6 octahedra that share corners with six equivalent OLi6 octahedra and faces with eight equivalent ClLi12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. Cl1- is bonded to twelve equivalent Li1+ atoms to form ClLi12 cuboctahedra that share corners with twelve equivalent ClLi12 cuboctahedra, faces with six equivalent ClLi12 cuboctahedra, and faces with eight equivalent OLi6 octahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca3AuN by Materials Project

Ca3AuN is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ca is bonded in a distorted linear geometry to four equivalent Au and two equivalent N atoms. All Ca–Au bond lengths are 3.43 Å. Both Ca–N bond lengths are 2.42 Å. Au is bonded to twelve equivalent Ca atoms to form AuCa12 cuboctahedra that share corners with twelve equivalent AuCa12 cuboctahedra, faces with six equivalent AuCa12 cuboctahedra, and faces with eight equivalent NCa6 octahedra. N is bonded to six equivalent Ca atoms to form NCa6 octahedra that share corners with six equivalent NCa6 octahedra and faces with eight equivalent AuCa12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na3BrO by Materials Project

Na3OBr is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Na1+ is bonded in a distorted linear geometry to two equivalent O2- and four equivalent Br1- atoms. Both Na–O bond lengths are 2.30 Å. All Na–Br bond lengths are 3.25 Å. O2- is bonded to six equivalent Na1+ atoms to form ONa6 octahedra that share corners with six equivalent ONa6 octahedra and faces with eight equivalent BrNa12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. Br1- is bonded to twelve equivalent Na1+ atoms to form BrNa12 cuboctahedra that share corners with twelve equivalent BrNa12 cuboctahedra, faces with six equivalent BrNa12 cuboctahedra, and faces with eight equivalent ONa6 octahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pd3N by Materials Project

Pd3N is alpha Rhenium trioxide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pd is bonded in a linear geometry to two equivalent N atoms. Both Pd–N bond lengths are 2.04 Å. N is bonded to six equivalent Pd atoms to form corner-sharing NPd6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N by Materials Project

C3N is alpha Rhenium trioxide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. C1+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.66 Å. N3- is bonded to six equivalent C1+ atoms to form corner-sharing NC6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu3PbC by Materials Project

Lu3PbC is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Lu is bonded in a distorted linear geometry to four equivalent Pb and two equivalent C atoms. All Lu–Pb bond lengths are 3.38 Å. Both Lu–C bond lengths are 2.39 Å. Pb is bonded to twelve equivalent Lu atoms to form PbLu12 cuboctahedra that share corners with twelve equivalent PbLu12 cuboctahedra, faces with six equivalent PbLu12 cuboctahedra, and faces with eight equivalent CLu6 octahedra. C is bonded to six equivalent Lu atoms to form CLu6 octahedra that share corners with six equivalent CLu6 octahedra and faces with eight equivalent PbLu12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3N4 by Materials Project

C3N4 crystallizes in the hexagonal P6_3/m space group. The structure is zero-dimensional and consists of two cyanide nitrogen molecules. C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.17 Å) and one longer (1.36 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three equivalent C4+ atoms. In the second N3- site, N3- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CSN2 by Materials Project

CN2S crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four aminothiocyanate molecules. C4+ is bonded in a distorted linear geometry to one N1- and one S2- atom. The C–N bond length is 1.17 Å. The C–S bond length is 1.87 Å. There are two inequivalent N1- sites. In the first N1- site, N1- is bonded in a single-bond geometry to one S2- atom. The N–S bond length is 1.48 Å. In the second N1- site, N1- is bonded in a single-bond geometry to one C4+ atom. S2- is bonded in a distorted single-bond geometry to one C4+ and one N1- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Yb3PbC by Materials Project

Yb3PbC is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Yb is bonded in a distorted linear geometry to four equivalent Pb and two equivalent C atoms. All Yb–Pb bond lengths are 3.54 Å. Both Yb–C bond lengths are 2.50 Å. Pb is bonded to twelve equivalent Yb atoms to form PbYb12 cuboctahedra that share corners with twelve equivalent PbYb12 cuboctahedra, faces with six equivalent PbYb12 cuboctahedra, and faces with eight equivalent CYb6 octahedra. C is bonded to six equivalent Yb atoms to form CYb6 octahedra that share corners with six equivalent CYb6 octahedra and faces with eight equivalent PbYb12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu3InO by Materials Project

(Eu3O)In is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Eu is bonded in a linear geometry to four equivalent In and two equivalent O atoms. All Eu–In bond lengths are 3.51 Å. Both Eu–O bond lengths are 2.48 Å. In is bonded to twelve equivalent Eu atoms to form InEu12 cuboctahedra that share corners with twelve equivalent InEu12 cuboctahedra, faces with six equivalent InEu12 cuboctahedra, and faces with eight equivalent OEu6 octahedra. O is bonded to six equivalent Eu atoms to form OEu6 octahedra that share corners with six equivalent OEu6 octahedra and faces with eight equivalent InEu12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3PbC by Materials Project

Ho3PbC is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ho is bonded in a distorted linear geometry to four equivalent Pb and two equivalent C atoms. All Ho–Pb bond lengths are 3.46 Å. Both Ho–C bond lengths are 2.44 Å. Pb is bonded to twelve equivalent Ho atoms to form PbHo12 cuboctahedra that share corners with twelve equivalent PbHo12 cuboctahedra, faces with six equivalent PbHo12 cuboctahedra, and faces with eight equivalent CHo6 octahedra. C is bonded to six equivalent Ho atoms to form CHo6 octahedra that share corners with six equivalent CHo6 octahedra and faces with eight equivalent PbHo12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AlFe3B by Materials Project

Fe3AlB is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Fe is bonded in a distorted linear geometry to four equivalent Al and two equivalent B atoms. All Fe–Al bond lengths are 2.70 Å. Both Fe–B bond lengths are 1.91 Å. Al is bonded to twelve equivalent Fe atoms to form AlFe12 cuboctahedra that share corners with twelve equivalent AlFe12 cuboctahedra, faces with six equivalent AlFe12 cuboctahedra, and faces with eight equivalent BFe6 octahedra. B is bonded to six equivalent Fe atoms to form BFe6 octahedra that share corners with six equivalent BFe6 octahedra and faces with eight equivalent AlFe12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si2O by Materials Project

SiOSi is high (beta) Cristobalite structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Si is bonded in a linear geometry to two equivalent O atoms. Both Si–O bond lengths are 2.03 Å. O is bonded to four equivalent Si atoms to form corner-sharing OSi4 tetrahedra.

36 MATERIALS SCIENCE↗
NASA NTRS1994

Digital Linear Tape (DLT) technology and product family overview

The demand that began a couple of years ago for increased data storage capacity continues. Peripheral Strategies (a Santa Barbara, California, Storage Market Research Firm) projects the amount of data stored on the average enterprise network will grow by 50 percent to 100 percent per year. Furthermore, Peripheral Strategies says that a typical mid-range workstation system containing 30GB to 50GB of storage today will grow at the rate of 50 percent per year. Dan Friedlander, a Boulder, Colorado-based consultant specializing in PC-LAN backup, says, 'The average NetWare LAN is about 8GB, but there are many that have 30GB to 300GB.....' The substantial growth of storage requirements has created various tape technologies that seek to satisfy the needs of today's and, especially, the next generations's systems and applications. There are five leading tape technologies in the market today: QIC (Quarter Inch Cartridge), IBM 3480/90, 8mm, DAT (Digital Audio Tape) and DLT (Digital Linear Tape). Product performance specifications and user needs have combined to classify these technologies into low-end, mid-range, and high-end systems applications. Although the manufacturers may try to position their products differently, product specifications and market requirements have determined that QIC and DAT are primarily low-end systems products while 8mm and DLT are competing for mid-range systems applications and the high-end systems space, where IBM compatibility is not required. The 3480/90 products seem to be used primarily in the IBM market, for interchangeability purposes. There are advantages and disadvantages for each of the tape technologies in the market today. We believe that DLT technology offers a significant number of very important features and specifications that make it extremely attractive for most current as well as emerging new applications, such as Hierarchical Storage Management (HSM). This paper will demonstrate why we think that the DLT technology and family of DLT products will become the technology of choice for most new applications in the mid-range and high-end (non-IBM) markets.

Lignos, Demetrios↗
DOE OSTI2020

Toward a scalable robust security-constrained optimal power flow using a proximal projection bundle method

Robust security-constrained optimal power flow (rSCOPF) aims to find the worst-case contingencies of alternating current optimal power flow (ACOPF) in power systems. With the rise of GPU architectures on the upcoming supercomputer architectures, optimization algorithms that rely on sparse linear algebra and indefinite linear systems are becoming increasingly hard to solve efficiently (e.g. interior-point method). To address this we revisit a maximin optimization formulation of the rSCOPF and the single-level mixed-integer semidefinite programming (MISDP) reformulation, which is obtained by taking the Lagrangian relaxation of the inner minimization ACOPF problem. In this paper, we focus on the development of a proximal projection bundle method (PPBM) for solving continuous relaxation node subproblems of the MISDP problem, based primarily on the well-known alternating direction method of multipliers. Cutting planes reminiscent of bundle method ideas are also applied in coordination with updates of the proximal parameter. The cutting-plane method can generate a large number of linear inequalities, leading to a large scale but decomposable quadratic programming (QP) subproblem that is amenable to GPUs. We present the numerical results on the IEEE 30, 57, 118, and 300-bus systems by using our PBMM method. We discuss the main computational bottleneck of our method, which is the time taken to solve each iteration of a QP subproblem instance of the PPBM, and how GPU architectures can accelerate this solution process.

bundle method↗
NASA NTRS1989

A simple, mass balance model of carbon flow in a controlled ecological life support system

Internal cycling of chemical elements is a fundamental aspect of a Controlled Ecological Life Support System (CELSS). Mathematical models are useful tools for evaluating fluxes and reservoirs of elements associated with potential CELSS configurations. A simple mass balance model of carbon flow in CELSS was developed based on data from the CELSS Breadboard project at Kennedy Space Center. All carbon reservoirs and fluxes were calculated based on steady state conditions and modelled using linear, donor-controlled transfer coefficients. The linear expression of photosynthetic flux was replaced with Michaelis-Menten kinetics based on dynamical analysis of the model which found that the latter produced more adequate model output. Sensitivity analysis of the model indicated that accurate determination of the maximum rate of gross primary production is critical to the development of an accurate model of carbon flow. Atmospheric carbon dioxide was particularly sensitive to changes in photosynthetic rate. The small reservoir of CO2 relative to large CO2 fluxes increases the potential for volatility in CO2 concentration. Feedback control mechanisms regulating CO2 concentration will probably be necessary in a CELSS to reduce this system instability.

Garland, Jay L.↗
NASA NTRS1999

Signal Prediction With Input Identification

A novel coding technique is presented for signal prediction with applications including speech coding, system identification, and estimation of input excitation. The approach is based on the blind equalization method for speech signal processing in conjunction with the geometric subspace projection theory to formulate the basic prediction equation. The speech-coding problem is often divided into two parts, a linear prediction model and excitation input. The parameter coefficients of the linear predictor and the input excitation are solved simultaneously and recursively by a conventional recursive least-squares algorithm. The excitation input is computed by coding all possible outcomes into a binary codebook. The coefficients of the linear predictor and excitation, and the index of the codebook can then be used to represent the signal. In addition, a variable-frame concept is proposed to block the same excitation signal in sequence in order to reduce the storage size and increase the transmission rate. The results of this work can be easily extended to the problem of disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. Simulations are included to demonstrate the proposed method.

Juang, Jer-Nan↗