The Normals to a Parabola and the Real Roots of a Cubic

ERIC Educational Resources Information Center

Bains, Majinder S.; Thoo, J. B.

2007-01-01

The geometric problem of finding the number of normals to the parabola y = x[squared] through a given point is equivalent to the algebraic problem of finding the number of distinct real roots of a cubic equation. Apollonius solved the former problem, and Cardano gave a solution to the latter. The two problems are bridged by Neil's (semi-cubical)…

Crystallography of decahedral and icosahedral particles. I - Geometry of twinning

NASA Technical Reports Server (NTRS)

Yang, C. Y.

1979-01-01

The crystal structure of the tetrahedral twins in multiply-twinned particles with decahedral and icosahedral point group symmetries has been examined and correlated with the face-centered cubic structure. Details on the crystal structure as well as the geometrical relationships among twins in each particle are presented. These crystallographic facts serve as a basis for the interpretation of small particle images obtained with advanced methods of transmission electron microscopy.

Northeastern forest survey revised cubic-foot volume equations

Treesearch

Charles T. Scott

1981-01-01

Cubic-foot volume equations are presented for the 17 species groups used in the forest survey of the 14 northeastern states. The previous cubic- foot volume equations were simple linear in form; the revised cubic-foot volume equations are nonlinear.

Least Squares Approximation By G1 Piecewise Parametric Cubes

DTIC Science & Technology

1993-12-01

ADDRESS(ES) 10.SPONSORING/MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and do not...CODE Approved for public release; distribution is unlimited. 13. ABSTRACT (maximum 200 words) Parametric piecewise cubic polynomials are used throughout...piecewise parametric cubic polynomial to a sequence of ordered points in the plane. Cubic Bdzier curves are used as a basis. The parameterization, the

Evaluation of the Seat Index Point Tool for Military Seats

DTIC Science & Technology

2014-12-01

millimeters mm2 ft2 squarefeet 0.093 square meters m2 yd2 square yard 0.836 square meters m2 Ac acres 0.405 hectares ha mi2 square miles 2.59 square...square miles mi2 VOLUME mL milliliters 0.034 fluid ounces fl oz L liters 0.264 gallons gal m3 cubic meters 35.314 cubic feet ft3 m3 cubic meters

The Coulombic Lattice Potential of Ionic Compounds: The Cubic Perovskites.

ERIC Educational Resources Information Center

Francisco, E.; And Others

1988-01-01

Presents coulombic models representing the particles of a system by point charges interacting through Coulomb's law to explain coulombic lattice potential. Uses rubidium manganese trifluoride as an example of cubic perovskite structure. Discusses the effects on cluster properties. (CW)

Buffer layers for coated conductors

DOEpatents

Stan, Liliana [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM; Foltyn, Stephen R [Los Alamos, NM

2011-08-23

A composite structure is provided including a base substrate, an IBAD oriented material upon the base substrate, and a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material. Additionally, an article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and a thick film upon the cubic metal oxide material. Finally, a superconducting article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and an yttrium barium copper oxide material upon the cubic metal oxide material.

Correlation between Resection Margin and Disease Recurrence with a Restricted Cubic Spline Model in Patients with Resected Hepatocellular Carcinoma.

PubMed

Lee, Woohyung; Han, Ho-Seong; Ahn, Soyeon; Yoon, Yoo-Seok; Cho, Jai Young; Choi, YoungRok

2018-01-17

The relationship between resection margin (RM) and recurrence of resected hepatocellular carcinoma (HCC) is unclear. We reviewed clinical data for 419 patients with HCC. The oncologic outcomes were compared between 2 groups of patients classified according to the inflexion point of the restricted cubic spline plot. The patients were divided according to an RM of <1 cm (n = 233; narrow RM group) or ≥1 cm (n = 186; wide RM group). The 5-year recurrence-free survival (RFS) rate was lower (34.8 vs. 43.8%, p = 0.042) and recurrence near the resection site was more frequent (4.7 vs. 0%, p = 0.010) in the narrow RM group. Patients with multiple lesions, or prior transarterial chemoembolization (TACE) or radiofrequency ablation (RFA) were excluded from subgroup analyses. In patients with a 2-5 cm HCC, the 5-year RFS was greater in the wide RM group (54.4 vs. 32.5%, p = 0.036). Narrow RM (hazard ratio 1.750, 95% CI 1.029-2.976, p = 0.039) was independently associated with disease recurrence. In patients with a single 2-5 cm HCC without prior TACE/RFA, an RM of ≥1 cm was associated with lower risk of recurrence after liver resection. © 2018 S. Karger AG, Basel.

A three-dimensional single-cell-resolution whole-brain atlas using CUBIC-X expansion microscopy and tissue clearing.

PubMed

Murakami, Tatsuya C; Mano, Tomoyuki; Saikawa, Shu; Horiguchi, Shuhei A; Shigeta, Daichi; Baba, Kousuke; Sekiya, Hiroshi; Shimizu, Yoshihiro; Tanaka, Kenji F; Kiyonari, Hiroshi; Iino, Masamitsu; Mochizuki, Hideki; Tainaka, Kazuki; Ueda, Hiroki R

2018-04-01

A three-dimensional single-cell-resolution mammalian brain atlas will accelerate systems-level identification and analysis of cellular circuits underlying various brain functions. However, its construction requires efficient subcellular-resolution imaging throughout the entire brain. To address this challenge, we developed a fluorescent-protein-compatible, whole-organ clearing and homogeneous expansion protocol based on an aqueous chemical solution (CUBIC-X). The expanded, well-cleared brain enabled us to construct a point-based mouse brain atlas with single-cell annotation (CUBIC-Atlas). CUBIC-Atlas reflects inhomogeneous whole-brain development, revealing a significant decrease in the cerebral visual and somatosensory cortical areas during postnatal development. Probabilistic activity mapping of pharmacologically stimulated Arc-dVenus reporter mouse brains onto CUBIC-Atlas revealed the existence of distinct functional structures in the hippocampal dentate gyrus. CUBIC-Atlas is shareable by an open-source web-based viewer, providing a new platform for whole-brain cell profiling.

Mass-induced instability of SAdS black hole in Einstein-Ricci cubic gravity

NASA Astrophysics Data System (ADS)

Myung, Yun Soo

2018-05-01

We perform the stability analysis of Schwarzschild-AdS (SAdS) black hole in the Einstein-Ricci cubic gravity. It shows that the Ricci tensor perturbations exhibit unstable modes for small black holes. We call this the mass-induced instability of SAdS black hole because the instability of small black holes arises from the massiveness in the linearized Einstein-Ricci cubic gravity, but not a feature of higher-order derivative theory giving ghost states. Also, we point out that the correlated stability conjecture holds for the SAdS black hole by computing the Wald entropy of SAdS black hole in Einstein-Ricci cubic gravity.

On local and global aspects of the 1:4 resonance in the conservative cubic Hénon maps

NASA Astrophysics Data System (ADS)

Gonchenko, M.; Gonchenko, S. V.; Ovsyannikov, I.; Vieiro, A.

2018-04-01

We study the 1:4 resonance for the conservative cubic Hénon maps C± with positive and negative cubic terms. These maps show up different bifurcation structures both for fixed points with eigenvalues ±i and for 4-periodic orbits. While for C-, the 1:4 resonance unfolding has the so-called Arnold degeneracy [the first Birkhoff twist coefficient equals (in absolute value) to the first resonant term coefficient], the map C+ has a different type of degeneracy because the resonant term can vanish. In the last case, non-symmetric points are created and destroyed at pitchfork bifurcations and, as a result of global bifurcations, the 1:4 resonant chain of islands rotates by π/4. For both maps, several bifurcations are detected and illustrated.

Analytical model for effect of temperature variation on PSF consistency in wavefront coding infrared imaging system

NASA Astrophysics Data System (ADS)

Feng, Bin; Shi, Zelin; Zhang, Chengshuo; Xu, Baoshu; Zhang, Xiaodong

2016-05-01

The point spread function (PSF) inconsistency caused by temperature variation leads to artifacts in decoded images of a wavefront coding infrared imaging system. Therefore, this paper proposes an analytical model for the effect of temperature variation on the PSF consistency. In the proposed model, a formula for the thermal deformation of an optical phase mask is derived. This formula indicates that a cubic optical phase mask (CPM) is still cubic after thermal deformation. A proposed equivalent cubic phase mask (E-CPM) is a virtual and room-temperature lens which characterizes the optical effect of temperature variation on the CPM. Additionally, a calculating method for PSF consistency after temperature variation is presented. Numerical simulation illustrates the validity of the proposed model and some significant conclusions are drawn. Given the form parameter, the PSF consistency achieved by a Ge-material CPM is better than the PSF consistency by a ZnSe-material CPM. The effect of the optical phase mask on PSF inconsistency is much slighter than that of the auxiliary lens group. A large form parameter of the CPM will introduce large defocus-insensitive aberrations, which improves the PSF consistency but degrades the room-temperature MTF.

A point particle model of lightly bound skyrmions

NASA Astrophysics Data System (ADS)

Gillard, Mike; Harland, Derek; Kirk, Elliot; Maybee, Ben; Speight, Martin

2017-04-01

A simple model of the dynamics of lightly bound skyrmions is developed in which skyrmions are replaced by point particles, each carrying an internal orientation. The model accounts well for the static energy minimizers of baryon number 1 ≤ B ≤ 8 obtained by numerical simulation of the full field theory. For 9 ≤ B ≤ 23, a large number of static solutions of the point particle model are found, all closely resembling size B subsets of a face centred cubic lattice, with the particle orientations dictated by a simple colouring rule. Rigid body quantization of these solutions is performed, and the spin and isospin of the corresponding ground states extracted. As part of the quantization scheme, an algorithm to compute the symmetry group of an oriented point cloud, and to determine its corresponding Finkelstein-Rubinstein constraints, is devised.

Nonlinear bias compensation of ZiYuan-3 satellite imagery with cubic splines

NASA Astrophysics Data System (ADS)

Cao, Jinshan; Fu, Jianhong; Yuan, Xiuxiao; Gong, Jianya

2017-11-01

Like many high-resolution satellites such as the ALOS, MOMS-2P, QuickBird, and ZiYuan1-02C satellites, the ZiYuan-3 satellite suffers from different levels of attitude oscillations. As a result of such oscillations, the rational polynomial coefficients (RPCs) obtained using a terrain-independent scenario often have nonlinear biases. In the sensor orientation of ZiYuan-3 imagery based on a rational function model (RFM), these nonlinear biases cannot be effectively compensated by an affine transformation. The sensor orientation accuracy is thereby worse than expected. In order to eliminate the influence of attitude oscillations on the RFM-based sensor orientation, a feasible nonlinear bias compensation approach for ZiYuan-3 imagery with cubic splines is proposed. In this approach, no actual ground control points (GCPs) are required to determine the cubic splines. First, the RPCs are calculated using a three-dimensional virtual control grid generated based on a physical sensor model. Second, one cubic spline is used to model the residual errors of the virtual control points in the row direction and another cubic spline is used to model the residual errors in the column direction. Then, the estimated cubic splines are used to compensate the nonlinear biases in the RPCs. Finally, the affine transformation parameters are used to compensate the residual biases in the RPCs. Three ZiYuan-3 images were tested. The experimental results showed that before the nonlinear bias compensation, the residual errors of the independent check points were nonlinearly biased. Even if the number of GCPs used to determine the affine transformation parameters was increased from 4 to 16, these nonlinear biases could not be effectively compensated. After the nonlinear bias compensation with the estimated cubic splines, the influence of the attitude oscillations could be eliminated. The RFM-based sensor orientation accuracies of the three ZiYuan-3 images reached 0.981 pixels, 0.890 pixels, and 1.093 pixels, which were respectively 42.1%, 48.3%, and 54.8% better than those achieved before the nonlinear bias compensation.

Rhombohedral cubic semiconductor materials on trigonal substrate with single crystal properties and devices based on such materials

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

2012-01-01

Growth conditions are developed, based on a temperature-dependent alignment model, to enable formation of cubic group IV, group II-V and group II-VI crystals in the [111] orientation on the basal (0001) plane of trigonal crystal substrates, controlled such that the volume percentage of primary twin crystal is reduced from about 40% to about 0.3%, compared to the majority single crystal. The control of stacking faults in this and other embodiments can yield single crystalline semiconductors based on these materials that are substantially without defects, or improved thermoelectric materials with twinned crystals for phonon scattering while maintaining electrical integrity. These methods can selectively yield a cubic-on-trigonal epitaxial semiconductor material in which the cubic layer is substantially either directly aligned, or 60 degrees-rotated from, the underlying trigonal material.

Definition of NASTRAN sets by use of parametric geometry

NASA Technical Reports Server (NTRS)

Baughn, Terry V.; Tiv, Mehran

1989-01-01

Many finite element preprocessors describe finite element model geometry with points, lines, surfaces and volumes. One method for describing these basic geometric entities is by use of parametric cubics which are useful for representing complex shapes. The lines, surfaces and volumes may be discretized for follow on finite element analysis. The ability to limit or selectively recover results from the finite element model is extremely important to the analyst. Equally important is the ability to easily apply boundary conditions. Although graphical preprocessors have made these tasks easier, model complexity may not lend itself to easily identify a group of grid points desired for data recovery or application of constraints. A methodology is presented which makes use of the assignment of grid point locations in parametric coordinates. The parametric coordinates provide a convenient ordering of the grid point locations and a method for retrieving the grid point ID's from the parent geometry. The selected grid points may then be used for the generation of the appropriate set and constraint cards.

Optimal cut-off points for waist circumference in the definition of metabolic syndrome in Brazilian adults: baseline analyses of the Longitudinal Study of Adult Health (ELSA-Brasil).

PubMed

Cardinal, Thiane Ristow; Vigo, Alvaro; Duncan, Bruce Bartholow; Matos, Sheila Maria Alvim; da Fonseca, Maria de Jesus Mendes; Barreto, Sandhi Maria; Schmidt, Maria Inês

2018-01-01

Waist circumference (WC) has been incorporated in the definition of the metabolic syndrome (MetS) but the exact WC cut-off points across populations are not clear. The Joint Interim Statement (JIS) suggested possible cut-offs to different populations and ethnic groups. However, the adequacy of these cut-offs to Brazilian adults has been scarcely investigated. The objective of the study is to evaluate possible WC thresholds to be used in the definition of MetS using data from the Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of civil servants (35-74 years old) of six Brazilian cities. We analyzed baseline data from 14,893 participants (6772 men and 8121 women). A MetS was defined according to the JIS criteria, but excluding WC and thus requiring 2 of the 4 remaining elements. We used restricted cubic spline regression to graph the relationship between WC and MetS. We identified optimal cut-off points which maximized joint sensitivity and specificity (Youden's index) from Receiver Operator Characteristic Curves. We also estimated the C-statistics using logistic regression. We found no apparent threshold for WC in restricted cubic spline plots. Optimal cut-off for men was 92 cm (2 cm lower than that recommended by JIS for Caucasian/Europids or Sub-Saharan African men), but 2 cm higher than that recommended for ethnic Central and South American. For women, optimal cut-off was 86, 6 cm higher than that recommended for Caucasian/Europids and ethnic Central and South American. Optimal cut-offs did not very across age groups and most common race/color categories (except for Asian men, 87 cm). Sex-specific cut-offs for WC recommended by JIS differ from optimal cut-offs we found for adult men and women of Brazil´s most common ethnic groups.

Weyl semimetals in optical lattices: moving and merging of Weyl points, and hidden symmetry at Weyl points

PubMed Central

Hou, Jing-Min; Chen, Wei

2016-01-01

We propose to realize Weyl semimetals in a cubic optical lattice. We find that there exist three distinct Weyl semimetal phases in the cubic optical lattice for different parameter ranges. One of them has two pairs of Weyl points and the other two have one pair of Weyl points in the Brillouin zone. For a slab geometry with (010) surfaces, the Fermi arcs connecting the projections of Weyl points with opposite topological charges on the surface Brillouin zone is presented. By adjusting the parameters, the Weyl points can move in the Brillouin zone. Interestingly, for two pairs of Weyl points, as one pair of them meet and annihilate, the originial two Fermi arcs coneect into one. As the remaining Weyl points annihilate further, the Fermi arc vanishes and a gap is opened. Furthermore, we find that there always exists a hidden symmetry at Weyl points, regardless of anywhere they located in the Brillouin zone. The hidden symmetry has an antiunitary operator with its square being −1. PMID:27644114

More practical critical height sampling.

Treesearch

Thomas B. Lynch; Jeffrey H. Gove

2015-01-01

Critical Height Sampling (CHS) (Kitamura 1964) can be used to predict cubic volumes per acre without using volume tables or equations. The critical height is defined as the height at which the tree stem appears to be in borderline condition using the point-sampling angle gauge (e.g. prism). An estimate of cubic volume per acre can be obtained from multiplication of the...

Tangent Lines without Derivatives for Quadratic and Cubic Equations

ERIC Educational Resources Information Center

Carroll, William J.

2009-01-01

In the quadratic equation, y = ax[superscript 2] + bx + c, the equation y = bx + c is identified as the equation of the line tangent to the parabola at its y-intercept. This is extended to give a convenient method of graphing tangent lines at any point on the graph of a quadratic or a cubic equation. (Contains 5 figures.)

On the structure of critical energy levels for the cubic focusing NLS on star graphs

NASA Astrophysics Data System (ADS)

Adami, Riccardo; Cacciapuoti, Claudio; Finco, Domenico; Noja, Diego

2012-05-01

We provide information on a non-trivial structure of phase space of the cubic nonlinear Schrödinger (NLS) on a three-edge star graph. We prove that, in contrast to the case of the standard NLS on the line, the energy associated with the cubic focusing Schrödinger equation on the three-edge star graph with a free (Kirchhoff) vertex does not attain a minimum value on any sphere of constant L2-norm. We moreover show that the only stationary state with prescribed L2-norm is indeed a saddle point.

Mepolizumab for Eosinophilic Chronic Obstructive Pulmonary Disease.

PubMed

Pavord, Ian D; Chanez, Pascal; Criner, Gerard J; Kerstjens, Huib A M; Korn, Stephanie; Lugogo, Njira; Martinot, Jean-Benoit; Sagara, Hironori; Albers, Frank C; Bradford, Eric S; Harris, Stephanie S; Mayer, Bhabita; Rubin, David B; Yancey, Steven W; Sciurba, Frank C

2017-10-26

Patients with chronic obstructive pulmonary disease (COPD) with an eosinophilic phenotype may benefit from treatment with mepolizumab, a monoclonal antibody directed against interleukin-5. We performed two phase 3, randomized, placebo-controlled, double-blind, parallel-group trials comparing mepolizumab (100 mg in METREX, 100 or 300 mg in METREO) with placebo, given as a subcutaneous injection every 4 weeks for 52 weeks in patients with COPD who had a history of moderate or severe exacerbations while taking inhaled glucocorticoid-based triple maintenance therapy. In METREX, unselected patients in the modified intention-to-treat population with an eosinophilic phenotype were stratified according to blood eosinophil count (≥150 per cubic millimeter at screening or ≥300 per cubic millimeter during the previous year). In METREO, all patients had a blood eosinophil count of at least 150 per cubic millimeter at screening or at least 300 per cubic millimeter during the previous year. The primary end point was the annual rate of moderate or severe exacerbations. Safety was also assessed. In METREX, the mean annual rate of moderate or severe exacerbations in the modified intention-to-treat population with an eosinophilic phenotype (462 patients) was 1.40 per year in the mepolizumab group versus 1.71 per year in the placebo group (rate ratio, 0.82; 95% confidence interval [CI], 0.68 to 0.98; adjusted P=0.04); no significant between-group differences were found in the overall modified intention-to-treat population (836 patients) (rate ratio, 0.98; 95% CI, 0.85 to 1.12; adjusted P>0.99). In METREO, the mean annual rate of moderate or severe exacerbations was 1.19 per year in the 100-mg mepolizumab group, 1.27 per year in the 300-mg mepolizumab group, and 1.49 per year in the placebo group. The rate ratios for exacerbations in the 100-mg and 300-mg mepolizumab groups versus the placebo group were 0.80 (95% CI, 0.65 to 0.98; adjusted P=0.07) and 0.86 (95% CI, 0.70 to 1.05; adjusted P=0.14), respectively. A greater effect of mepolizumab, as compared with placebo, on the annual rate of moderate or severe exacerbations was found among patients with higher blood eosinophil counts at screening. The safety profile of mepolizumab was similar to that of placebo. Mepolizumab at a dose of 100 mg was associated with a lower annual rate of moderate or severe exacerbations than placebo among patients with COPD and an eosinophilic phenotype. This finding suggests that eosinophilic airway inflammation contributes to COPD exacerbations. (Funded by GlaxoSmithKline; METREX and METREO ClinicalTrials.gov numbers, NCT02105948 and NCT02105961 .).

Interpolation and Polynomial Curve Fitting

ERIC Educational Resources Information Center

Yang, Yajun; Gordon, Sheldon P.

2014-01-01

Two points determine a line. Three noncollinear points determine a quadratic function. Four points that do not lie on a lower-degree polynomial curve determine a cubic function. In general, n + 1 points uniquely determine a polynomial of degree n, presuming that they do not fall onto a polynomial of lower degree. The process of finding such a…

Reentrant behavior in the nearest-neighbor Ising antiferromagnet in a magnetic field

NASA Astrophysics Data System (ADS)

Neto, Minos A.; de Sousa, J. Ricardo

2004-12-01

Motived by the H-T phase diagram in the bcc Ising antiferromagnetic with nearest-neighbor interactions obtained by Monte Carlo simulation [Landau, Phys. Rev. B 16, 4164 (1977)] that shows a reentrant behavior at low temperature, with two critical temperatures in magnetic field about 2% greater than the critical value Hc=8J , we apply the effective field renormalization group (EFRG) approach in this model on three-dimensional lattices (simple cubic-sc and body centered cubic-bcc). We find that the critical curve TN(H) exhibits a maximum point around of H≃Hc only in the bcc lattice case. We also discuss the critical behavior by the effective field theory in clusters with one (EFT-1) and two (EFT-2) spins, and a reentrant behavior is observed for the sc and bcc lattices. We have compared our results of EFRG in the bcc lattice with Monte Carlo and series expansion, and we observe a good accordance between the methods.

Functional renormalization group approach to the Yang-Lee edge singularity

DOE PAGES

An, X.; Mesterházy, D.; Stephanov, M. A.

2016-07-08

Here, we determine the scaling properties of the Yang-Lee edge singularity as described by a one-component scalar field theory with imaginary cubic coupling, using the nonperturbative functional renormalization group in 3 ≤ d ≤ 6 Euclidean dimensions. We find very good agreement with high-temperature series data in d = 3 dimensions and compare our results to recent estimates of critical exponents obtained with the four-loop ϵ = 6 - d expansion and the conformal bootstrap. The relevance of operator insertions at the corresponding fixed point of the RG β functions is discussed and we estimate the error associated with O(∂more » 4) truncations of the scale-dependent effective action.« less

Functional renormalization group approach to the Yang-Lee edge singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, X.; Mesterházy, D.; Stephanov, M. A.

Here, we determine the scaling properties of the Yang-Lee edge singularity as described by a one-component scalar field theory with imaginary cubic coupling, using the nonperturbative functional renormalization group in 3 ≤ d ≤ 6 Euclidean dimensions. We find very good agreement with high-temperature series data in d = 3 dimensions and compare our results to recent estimates of critical exponents obtained with the four-loop ϵ = 6 - d expansion and the conformal bootstrap. The relevance of operator insertions at the corresponding fixed point of the RG β functions is discussed and we estimate the error associated with O(∂more » 4) truncations of the scale-dependent effective action.« less

Structural and electronic properties of Sr{sub x}Ba{sub 1-x}SnO{sub 3} from first principles calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreira, E.; Henriques, J.M.; Azevedo, D.L.

2012-03-15

Neutron diffraction data for Sr{sub x}Ba{sub 1-x}SnO{sub 3} (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) solid solutions were used as inputs to obtain optimized geometries and electronic properties using the density functional theory (DFT) formalism considering both the local density and generalized gradient approximations, LDA and GGA, respectively. The crystal structures and SnO{sub 6} octahedra tilting angles found after total energy minimization agree well with experiment, specially for the GGA data. Elastic constants were also obtained and compared with theoretical and experimental results for cubic BaSnO{sub 3}. While the alloys with cubic unit cell have an indirect band gap, tetragonalmore » and orthorhombic alloys exhibit direct band gaps (exception made to x=1.0). The Kohn-Sham minimum electronic band gap oscillates from 1.52 eV (cubic x=0.0, LDA) to 2.61 eV (orthorhombic x=1.0, LDA), and from 0.74 eV (cubic BaSnO{sub 3}, GGA) to 1.97 eV (orthorhombic SrSnO{sub 3}, GGA). Parabolic interpolation of bands has allowed us to estimate the effective masses for charge carriers, which are shown to be anisotropic and larger for holes. - Graphical Abstract: Highlights: Black-Right-Pointing-Pointer DFT calculations were performed on Sr{sub x}Ba{sub 1-x}SnO{sub 3} solid solutions. Black-Right-Pointing-Pointer Calculated crystal structures agree well with experiment. Black-Right-Pointing-Pointer Alloys have direct or indirect gaps depending on the Sr molar fraction. Black-Right-Pointing-Pointer The Kohn-Sham gap variation from x=0.0 to x=1.0 is close to the experimental value. Black-Right-Pointing-Pointer Carrier effective masses are very anisotropic, specially for holes.« less

High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

DOE PAGES

Ueland, B. G.; Saunders, S. M.; Bud'ko, S. L.; ...

2015-11-30

In this study, YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T*=0.7K, fragile antiferromagnetic order below T N = 0.4K, a Kondo temperature of T K ≈ 1K, and crystalline-electric-field splitting on the order of E/k B = 1 – 10K. Whereas the compound has a face-centered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 – 10more » × 10 –5 Å, no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 ≲ T ≲ 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb 3+ residing on a site with either cubic or less than cubic point symmetry.« less

A grid spacing control technique for algebraic grid generation methods

NASA Technical Reports Server (NTRS)

Smith, R. E.; Kudlinski, R. A.; Everton, E. L.

1982-01-01

A technique which controls the spacing of grid points in algebraically defined coordinate transformations is described. The technique is based on the generation of control functions which map a uniformly distributed computational grid onto parametric variables defining the physical grid. The control functions are smoothed cubic splines. Sets of control points are input for each coordinate directions to outline the control functions. Smoothed cubic spline functions are then generated to approximate the input data. The technique works best in an interactive graphics environment where control inputs and grid displays are nearly instantaneous. The technique is illustrated with the two-boundary grid generation algorithm.

Off-line data reduction

NASA Astrophysics Data System (ADS)

Gutowski, Marek W.

1992-12-01

Presented is a novel, heuristic algorithm, based on fuzzy set theory, allowing for significant off-line data reduction. Given the equidistant data, the algorithm discards some points while retaining others with their original values. The fraction of original data points retained is typically {1}/{6} of the initial value. The reduced data set preserves all the essential features of the input curve. It is possible to reconstruct the original information to high degree of precision by means of natural cubic splines, rational cubic splines or even linear interpolation. Main fields of application should be non-linear data fitting (substantial savings in CPU time) and graphics (storage space savings).

Sharing Teaching Ideas.

ERIC Educational Resources Information Center

Touval, Ayana

1992-01-01

Introduces the concept of maximum and minimum function values as turning points on the function's graphic representation and presents a method for finding these values without using calculus. The process of utilizing transformations to find the turning point of a quadratic function is extended to find the turning points of cubic functions. (MDH)

Breakup of Kol'mogorov-Arnol'd-Moser tori of cubic irrational winding number

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, J.; Helleman, R.H.G.

1989-01-01

For the special case in which the irrational winding number is the root of a cubic equation, we present numerical evidence for the validity of some form of residue criterion (Greene, J. Math. Phys. 20, 1182 (1979)). This is a criterion for the breakup of Kol'mogorov-Arnol'd-Moser tori in two degrees of freedom. The cubic case is essential for future work on four-dimensional maps. While the residues do approach infinity (respectively, 0) after (respectively, before) the breaking point, it is numerically very difficult to estimate a critical residue value R/sub cr/ for this cubic case (0.15approx. ..infinity, with a ''new'' scalingmore » constant xiapprox. =0.72, where p/sub n//q/sub n/ is the nth rational approximant in the continued-fraction expansion of the cubic irrational. For a quadratic irrational this scaling reduces to the usual power-law scaling approx.delta/sup -//sup n/.« less

Classification of Arnold-Beltrami flows and their hidden symmetries

NASA Astrophysics Data System (ADS)

Fré, P.; Sorin, A. S.

2015-07-01

In the context of mathematical hydrodynamics, we consider the group theory structure which underlies the so named ABC flows introduced by Beltrami, Arnold and Childress. Main reference points are Arnold's theorem stating that, for flows taking place on compact three manifolds ℳ3, the only velocity fields able to produce chaotic streamlines are those satisfying Beltrami equation and the modern topological conception of contact structures, each of which admits a representative contact one-form also satisfying Beltrami equation. We advocate that Beltrami equation is nothing else but the eigenstate equation for the first order Laplace-Beltrami operator ★ g d, which can be solved by using time-honored harmonic analysis. Taking for ℳ3, a torus T 3 constructed as ℝ3/Λ, where Λ is a crystallographic lattice, we present a general algorithm to construct solutions of the Beltrami equation which utilizes as main ingredient the orbits under the action of the point group B A of three-vectors in the momentum lattice *Λ. Inspired by the crystallographic construction of space groups, we introduce the new notion of a Universal Classifying Group which contains all space groups as proper subgroups. We show that the ★ g d eigenfunctions are naturally arranged into irreducible representations of and by means of a systematic use of the branching rules with respect to various possible subgroups we search and find Beltrami fields with non trivial hidden symmetries. In the case of the cubic lattice the point group is the proper octahedral group O24 and the Universal Classifying Group is a finite group G1536 of order |G1536| = 1536 which we study in full detail deriving all of its 37 irreducible representations and the associated character table. We show that the O24 orbits in the cubic lattice are arranged into 48 equivalence classes, the parameters of the corresponding Beltrami vector fields filling all the 37 irreducible representations of G1536. In this way we obtain an exhaustive classification of all generalized ABC- flows and of their hidden symmetries. We make several conceptual comments about the need of a field-theory yielding Beltrami equation as a field equation and/or an instanton equation and on the possible relation of Arnold-Beltrami flows with (supersymmetric) Chern-Simons gauge theories. We also suggest linear generalizations of Beltrami equation to higher odd-dimensions that are different from the non-linear one proposed by Arnold and possibly make contact with M-theory and the geometry of flux-compactifications.

22 CFR 202.7 - Documentation required for reimbursement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Voucher for Purchases and Services Other than Personal”—Voucher SF 1034 in original and three copies to be... relevant weights, cubic measurements, rates, and any applicable tariff surcharges. (2) To points of entry. (i) Where the shipment is made to a point of entry and through bills of lading to designated point of...

The electric field of a uniformly charged cubic shell

NASA Astrophysics Data System (ADS)

McCreery, Kaitlin; Greenside, Henry

2018-01-01

As an integrative and insightful example for undergraduates learning about electrostatics, we discuss how to use symmetry, Coulomb's law, superposition, Gauss's law, and visualization to understand the electric field E (x ,y ,z ) produced by a uniformly charged cubic shell. We first discuss how to deduce qualitatively, using freshman-level physics, the perhaps surprising fact that the interior electric field is nonzero and has a complex structure, pointing inwards from the middle of each face of the shell and pointing outwards towards each edge and corner. We then discuss how to understand the quantitative features of the electric field by plotting an analytical expression for E along symmetry lines and on symmetry surfaces of the shell.

Physical characteristics and quality of water from selected springs and wells in the Lincoln Point-Bird Island area, Utah Lake, Utah

USGS Publications Warehouse

Baskin, R.L.; Spangler, L.E.; Holmes, W.F.

1994-01-01

From February 1991 to October 1992, the U.S. Geological Survey, in cooperation with the Central Utah Water Conservancy District, investigated the hydrology of the Lincoln Point - Bird Island area in the southeast part of Utah Lake, Utah. The investigation included measurements of the discharge of selected springs and measurements of the physical and chemical characteristics of water from selected springs and wells in the LincolnPoint - Bird Island area. This report contains data for twenty-one distinct springs in the study area including two springs beneath the surface of Utah Lake at Bird Island. Data from this study, combined with data from previous studies, indicate that the location of springs in the Lincoln Point - Bird Island area probably is controlled by fractures that are the result of faulting. Measured discharge of springs in the Lincoln Point - Bird Island area ranged from less than 0.01 cubic foot per second to 0.84 cubic foot per second. Total discharge in the study area, including known unmeasured springs and seeps, is estimated to be about 5 cubic feet per second. Reported and measured temperatures of water from springs and wells in the Lincoln Point - Bird Island area ranged from 16.0 degrees Celsius to 36.5 degrees Celsius. Dissolved-solids con-centrations ranged from 444 milligrams per liter to 7,932 milligrams per liter, and pH ranged from 6.3 to 8.1. Physical and chemical characteristics of spring and well water from the west side of Lincoln Point were virtually identical to the physical and chemical characteristics of water from the submerged Bird Island springs, indicating a similar source for the water. Water chemistry, isotope analyses, and geothermometer calculations indicate deep circulation of water discharging from the springs and indicate that the source of recharge for the springs at Lincoln Point and Bird Island does not appear to be localized in the LincolnPoint - Bird Island area.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filippov, A. V., E-mail: fav@triniti.ru

The interaction of two charged point macroparticles located in Wigner–Seitz cells of simple cubic (SC), body-centered cubic (BCC), or face-centered cubic (FCC) lattices in an equilibrium plasma has been studied within the Debye approximation or, more specifically, based on the linearized Poisson–Boltzmann model. The shape of the outer boundary is shown to exert a strong influence on the pattern of electrostatic interaction between the two macroparticles, which transforms from repulsion at small interparticle distances to attraction as the interparticle distance approaches half the length of the computational cell. The macroparticle pair interaction potential in an equilibrium plasma is shown tomore » be nevertheless the Debye one and purely repulsive for likely charged macroparticles.« less

Itinerant ferromagnetism in fermionic systems with SP (2 N) symmetry

NASA Astrophysics Data System (ADS)

Yang, Wang; Wu, Congjun

The Ginzburg-Landau free energy of systems with SP (2 N) symmetry describes a second order phase transition on the mean field level, since the Casimir invariants of the SP (2 N) group can be only of even order combinations of the generators of the SP (2 N) group. This is in contrast with systems having the SU (N) symmetry, where the allowance of cubic term generally makes the phase transition into first order. In this work, we consider the Hertz-Millis type itinerant ferromagnetism in an interacting fermionic system with SP (2 N) symmetry, where the ferromagnetic orders are enriched by the multi-component nature of the system. The quantum criticality is discussed near the second order phase transition point.

Curvelet-domain multiple matching method combined with cubic B-spline function

NASA Astrophysics Data System (ADS)

Wang, Tong; Wang, Deli; Tian, Mi; Hu, Bin; Liu, Chengming

2018-05-01

Since the large amount of surface-related multiple existed in the marine data would influence the results of data processing and interpretation seriously, many researchers had attempted to develop effective methods to remove them. The most successful surface-related multiple elimination method was proposed based on data-driven theory. However, the elimination effect was unsatisfactory due to the existence of amplitude and phase errors. Although the subsequent curvelet-domain multiple-primary separation method achieved better results, poor computational efficiency prevented its application. In this paper, we adopt the cubic B-spline function to improve the traditional curvelet multiple matching method. First, select a little number of unknowns as the basis points of the matching coefficient; second, apply the cubic B-spline function on these basis points to reconstruct the matching array; third, build constraint solving equation based on the relationships of predicted multiple, matching coefficients, and actual data; finally, use the BFGS algorithm to iterate and realize the fast-solving sparse constraint of multiple matching algorithm. Moreover, the soft-threshold method is used to make the method perform better. With the cubic B-spline function, the differences between predicted multiple and original data diminish, which results in less processing time to obtain optimal solutions and fewer iterative loops in the solving procedure based on the L1 norm constraint. The applications to synthetic and field-derived data both validate the practicability and validity of the method.

The influence of coordinated defects on inhomogeneous broadening in cubic lattices

NASA Astrophysics Data System (ADS)

Matheson, P. L.; Sullivan, Francis P.; Evenson, William E.

2016-12-01

The joint probability distribution function (JPDF) of electric field gradient (EFG) tensor components in cubic materials is dominated by coordinated pairings of defects in shells near probe nuclei. The contributions from these inner shell combinations and their surrounding structures contain the essential physics that determine the PAC-relevant quantities derived from them. The JPDF can be used to predict the nature of inhomogeneous broadening (IHB) in perturbed angular correlation (PAC) experiments by modeling the G 2 spectrum and finding expectation values for V zz and η. The ease with which this can be done depends upon the representation of the JPDF. Expanding on an earlier work by Czjzek et al. (Hyperfine Interact. 14, 189-194, 1983), Evenson et al. (Hyperfine Interact. 237, 119, 2016) provide a set of coordinates constructed from the EFG tensor invariants they named W 1 and W 2. Using this parameterization, the JPDF in cubic structures was constructed using a point charge model in which a single trapped defect (TD) is the nearest neighbor to a probe nucleus. Individual defects on nearby lattice sites pair with the TD to provide a locus of points in the W 1- W 2 plane around which an amorphous-like distribution of probability density grows. Interestingly, however, marginal, separable PDFs appear adequate to model IHB relevant cases. We present cases from simulations in cubic materials illustrating the importance of these near-shell coordinations.

Aperture shape dependencies in extended depth of focus for imaging camera by wavefront coding

NASA Astrophysics Data System (ADS)

Sakita, Koichi; Ohta, Mitsuhiko; Shimano, Takeshi; Sakemoto, Akito

2015-02-01

Optical transfer functions (OTFs) on various directional spatial frequency axes for cubic phase mask (CPM) with circular and square apertures are investigated. Although OTF has no zero points, it has a very close value to zero for a circular aperture at low frequencies on diagonal axis, which results in degradation of restored images. The reason for close-to-zero value in OTF is also analyzed in connection with point spread function profiles using Fourier slice theorem. To avoid close-to-zero condition, square aperture with CPM is indispensable in WFC. We optimized cubic coefficient α of CPM and coefficients of digital filter, and succeeded to get excellent de-blurred images at large depth of field.

Correlation of materials properties with the atomic density concept

NASA Technical Reports Server (NTRS)

1975-01-01

Based on the hypothesis that the number of atoms per unit volume, accurately calculable for any substance of known real density and chemical composition, various characterizing parameters (energy levels of electrons interacting among atoms of the same or different kinds, atomic mass, bond intensity) were chosen for study. A multiple exponential equation was derived to express the relationship. Various properties were examined, and correlated with the various parameters. Some of the properties considered were: (1) heat of atomization, (2) boiling point, (3) melting point, (4) shear elastic modulus of cubic crystals, (5) thermal conductivity, and (6) refractive index for transparent substances. The solid elements and alkali halides were the materials studied. It is concluded that the number of different properties can quantitively be described by a common group of parameters for the solid elements, and a wide variety of compounds.

Cubic spline numerical solution of an ablation problem with convective backface cooling

NASA Astrophysics Data System (ADS)

Lin, S.; Wang, P.; Kahawita, R.

1984-08-01

An implicit numerical technique using cubic splines is presented for solving an ablation problem on a thin wall with convective cooling. A non-uniform computational mesh with 6 grid points has been used for the numerical integration. The method has been found to be computationally efficient, providing for the care under consideration of an overall error of about 1 percent. The results obtained indicate that the convective cooling is an important factor in reducing the ablation thickness.

Elevation data fitting and precision analysis of Google Earth in road survey

NASA Astrophysics Data System (ADS)

Wei, Haibin; Luan, Xiaohan; Li, Hanchao; Jia, Jiangkun; Chen, Zhao; Han, Leilei

2018-05-01

Objective: In order to improve efficiency of road survey and save manpower and material resources, this paper intends to apply Google Earth to the feasibility study stage of road survey and design. Limited by the problem that Google Earth elevation data lacks precision, this paper is focused on finding several different fitting or difference methods to improve the data precision, in order to make every effort to meet the accuracy requirements of road survey and design specifications. Method: On the basis of elevation difference of limited public points, any elevation difference of the other points can be fitted or interpolated. Thus, the precise elevation can be obtained by subtracting elevation difference from the Google Earth data. Quadratic polynomial surface fitting method, cubic polynomial surface fitting method, V4 interpolation method in MATLAB and neural network method are used in this paper to process elevation data of Google Earth. And internal conformity, external conformity and cross correlation coefficient are used as evaluation indexes to evaluate the data processing effect. Results: There is no fitting difference at the fitting point while using V4 interpolation method. Its external conformity is the largest and the effect of accuracy improvement is the worst, so V4 interpolation method is ruled out. The internal and external conformity of the cubic polynomial surface fitting method both are better than those of the quadratic polynomial surface fitting method. The neural network method has a similar fitting effect with the cubic polynomial surface fitting method, but its fitting effect is better in the case of a higher elevation difference. Because the neural network method is an unmanageable fitting model, the cubic polynomial surface fitting method should be mainly used and the neural network method can be used as the auxiliary method in the case of higher elevation difference. Conclusions: Cubic polynomial surface fitting method can obviously improve data precision of Google Earth. The error of data in hilly terrain areas meets the requirement of specifications after precision improvement and it can be used in feasibility study stage of road survey and design.

Flood of September 3, 1972, in Hillsboro, New Mexico

USGS Publications Warehouse

Waite, Loyd A.

1973-01-01

Four deaths, two persons seriously injured, and property damage estimated at $846,500 resulted from a flood that struck the village of Hillsboro, N. Mex. during the early morning hours of September 3, 1972. Hillsboro is situated at the confluence of Percha Creek and its main tributary, North Percha Creek. Heavy rainfall in the drainage basin upstream from Hillsboro occurred during the night of September 2-3. Peak discharge computed by slope-area measurements indicated that Percha Creek carried a maximum flow of 12,200 cubic feet per second (346 cubic meters per second) and that North Percha Creek carried a flow of 20,900 cubic feet per second (592 cubic meters per second) at points just upstream from Hillsboro. Flood-control facilities in Hillsboro consisting of levees on the south bank of Percha Creek failed and flood waters reached depths of 6 feet (1.8 meters) in Hillsboro. Hillsboro was declared a disaster area by Governor Bruce King and by President Richard Nixon.

Cubic and orthorhombic structures of aluminum hydride Al H3 predicted by a first-principles study

NASA Astrophysics Data System (ADS)

Ke, Xuezhi; Kuwabara, Akihide; Tanaka, Isao

2005-05-01

The most stable structure of aluminum hydride AlH3 is believed to be a hexagonal symmetry. However, using the density functional theory, we have identified two more stable structures for the AlH3 with the cubic and orthorhombic symmetries. Based on the quasiharmonic approximation, the cubic and orthorhombic AlH3 are almost degenerate when the zero-point energies are included. The geometric and electronic structures, the phonon, and the thermodynamic properties for the hexagonal, cubic, and orthorhombic AlH3 have been studied by means of density functional theory and direct ab initio force constant approach. The calculated electronic structures, phonon density of states, and thermodynamic functions [including S(T) and H(T)-H(0) ] for the three hydrides are similar. The results show that these three hydrides have negative enthalpies of formation, but positive free energies of formation. This conclusion is the same as that made by Wolverton for the hexagonal AlH3 [Phys. Rev. B 69, 144109 (2004)]. The thermodynamic properties indicate that the orthorhombic and cubic AlH3 should be more difficult to dissociate than the hexagonal AlH3 .

Molecular structure of Ti8C12 and related complexes.

PubMed Central

Pauling, L

1992-01-01

Application of valence-bond theory leads to the assignment to the molecule Ti8C12 of a cubic structure, point group Ohm3m, with 8 Ti at the cube corners, +/-(x x x, x, x x [symbol, see text]) where x = 1.78 A, and with 12 C in pairs in the cube faces, +/-(0 y z, [symbol, see text], 0, y z [symbol, see text]) where y = 1.78 A and z = 0.71 A. The Ti-C and C-C bonds have bond number 4/3, corresponding to resonance of single and double bonds in 2:1 ratio. PMID:11607323

Structure of the orthorhombic form of Mn(2)Al(7), Fe(2)Al(7), and (Mn(0.7)Fe(0.3))(2)Al(7) that by twinning produces grains with decagonal point-group symmetry.

PubMed

Pauling, L

1988-04-01

Analysis of electron diffraction photographs of grains of Mn(2)Al(7), Fe(2)Al(7), and (Mn(0.7)Fe(0.3))(2)Al(7) leads to the conclusion that they are 5-fold twins of a 1664-atom orthorhombic crystal with a = 32.86 A, b = 31.23 A, and c = 24.80 A and with 16 icosahedral clusters of 104 atoms in positions shifted by small amounts from those of the cubic beta-tungsten structure.

Structure of the orthorhombic form of Mn2Al7, Fe2Al7, and (Mn0.7Fe0.3)2Al7 that by twinning produces grains with decagonal point-group symmetry

PubMed Central

Pauling, Linus

1988-01-01

Analysis of electron diffraction photographs of grains of Mn2Al7, Fe2Al7, and (Mn0.7Fe0.3)2Al7 leads to the conclusion that they are 5-fold twins of a 1664-atom orthorhombic crystal with a = 32.86 Å, b = 31.23 Å, and c = 24.80 Å and with 16 icosahedral clusters of 104 atoms in positions shifted by small amounts from those of the cubic β-tungsten structure. PMID:16593921

Hairy black holes in cubic quasi-topological gravity

NASA Astrophysics Data System (ADS)

Dykaar, Hannah; Hennigar, Robie A.; Mann, Robert B.

2017-05-01

We construct a class of five dimensional black hole solutions to cubic quasi-topological gravity with conformal scalar hair and study their thermodynamics. We find these black holes provide the second example of black hole λ-lines: a line of second order (continuous) phase transitions, akin to the fluid/superfluid transition of 4He. Examples of isolated critical points are found for spherical black holes, marking the first in the literature to date. We also find various novel and interesting phase structures, including an isolated critical point occurring in conjunction with a double reentrant phase transition. The AdS vacua of the theory are studied, finding ghost-free configurations where the scalar field takes on a non-zero constant value, in notable contrast to the five dimensional Lovelock case.

Freezing, melting and structure of ice in a hydrophilic nanopore.

PubMed

Moore, Emily B; de la Llave, Ezequiel; Welke, Kai; Scherlis, Damian A; Molinero, Valeria

2010-04-28

The nucleation, growth, structure and melting of ice in 3 nm diameter hydrophilic nanopores are studied through molecular dynamics simulations with the mW water model. The melting temperature of water in the pore was T(m)(pore) = 223 K, 51 K lower than the melting point of bulk water in the model and in excellent agreement with experimental determinations for 3 nm silica pores. Liquid and ice coexist in equilibrium at the melting point and down to temperatures as low as 180 K. Liquid water is located at the interface of the pore wall, increasing from one monolayer at the freezing temperature, T(f)(pore) = 195 K, to two monolayers a few degrees below T(m)(pore). Crystallization of ice in the pore occurs through homogeneous nucleation. At the freezing temperature, the critical nucleus contains approximately 75 to 100 molecules, with a radius of gyration similar to the radius of the pore. The critical nuclei contain features of both cubic and hexagonal ice, although stacking of hexagonal and cubic layers is not defined until the nuclei reach approximately 150 molecules. The structure of the confined ice is rich in stacking faults, in agreement with the interpretation of X-ray and neutron diffraction experiments. Though the presence of cubic layers is twice as prevalent as hexagonal ones, the crystals should not be considered defective Ic as sequences with more than three adjacent cubic (or hexagonal) layers are extremely rare in the confined ice.

Improved Magnetic STAR Methods for Real-Time, Point-by-Point Localization of Unexploded Ordnance and Buried Mines

DTIC Science & Technology

2008-09-01

of magnetic UXO. The prototype STAR Sensor comprises: a) A cubic array of eight fluxgate magnetometers . b) A 24-channel data acquisition/signal...array (shaded boxes) of eight low noise Triaxial Fluxgate Magnetometers (TFM) develops 24 channels of vector B- field data. Processor hardware

Smoothing data series by means of cubic splines: quality of approximation and introduction of a repeating spline approach

NASA Astrophysics Data System (ADS)

Wüst, Sabine; Wendt, Verena; Linz, Ricarda; Bittner, Michael

2017-09-01

Cubic splines with equidistant spline sampling points are a common method in atmospheric science, used for the approximation of background conditions by means of filtering superimposed fluctuations from a data series. What is defined as background or superimposed fluctuation depends on the specific research question. The latter also determines whether the spline or the residuals - the subtraction of the spline from the original time series - are further analysed.Based on test data sets, we show that the quality of approximation of the background state does not increase continuously with an increasing number of spline sampling points and/or decreasing distance between two spline sampling points. Splines can generate considerable artificial oscillations in the background and the residuals.We introduce a repeating spline approach which is able to significantly reduce this phenomenon. We apply it not only to the test data but also to TIMED-SABER temperature data and choose the distance between two spline sampling points in a way that is sensitive for a large spectrum of gravity waves.

Bcc and Fcc transition metals and alloys: a central role for the Jahn-Teller effect in explaining their ideal and distorted structures.

PubMed

Lee, Stephen; Hoffmann, Roald

2002-05-01

Transition metal elements, alloys, and intermetallic compounds often adopt the body centered cubic (bcc) and face centered cubic (fcc) structures. By comparing quantitative density functional with qualitative tight-binding calculations, we analyze the electronic factors which make the bcc and fcc structures energetically favorable. To do so, we develop a tight-binding function, DeltaE(star), a function that measures the energetic effects of transferring electrons within wave vector stars. This function allows one to connect distortions in solids to the Jahn-Teller effect in molecules and to provide an orbital perspective on structure determining deformations in alloys. We illustrate its use by considering first a two-dimensional square net. We then turn to three-dimensional fcc and bcc structures, and distortions of these. Using DeltaE(star), we rationalize the differences in energy of these structures. We are able to deduce which orbitals are responsible for instabilities in seven to nine valence electron per atom (e(-)/a) bcc systems and five and six e(-)/a fcc structures. Finally we demonstrate that these results account for the bcc and fcc type structures found in both the elements and binary intermetallic compounds of group 4 through 9 transition metal atoms. The outline of a theory of metal structure deformations based on loss of point group operation rather than translational symmetry is presented.

Kohn anomalies in momentum dependence of magnetic susceptibility of some three-dimensional systems

NASA Astrophysics Data System (ADS)

Stepanenko, A. A.; Volkova, D. O.; Igoshev, P. A.; Katanin, A. A.

2017-11-01

We study a question of the presence of Kohn points, yielding at low temperatures nonanalytic momentum dependence of magnetic susceptibility near its maximum, in electronic spectra of some threedimensional systems. In particular, we consider a one-band model on face-centered cubic lattice with hopping between the nearest and next-nearest neighbors, which models some aspects of the dispersion of ZrZn2, and the two-band model on body-centered cubic lattice, modeling the dispersion of chromium. For the former model, it is shown that Kohn points yielding maxima of susceptibility exist in a certain (sufficiently wide) region of electronic concentrations; the dependence of the wave vectors, corresponding to the maxima, on the chemical potential is investigated. For the two-band model, we show the existence of the lines of Kohn points, yielding maximum susceptibility, whose position agrees with the results of band structure calculations and experimental data on the wave vector of antiferromagnetism of chromium.

Non-minimally coupled quintessence dark energy model with a cubic galileon term: a dynamical system analysis

NASA Astrophysics Data System (ADS)

Bhattacharya, Somnath; Mukherjee, Pradip; Roy, Amit Singha; Saha, Anirban

2018-03-01

We consider a scalar field which is generally non-minimally coupled to gravity and has a characteristic cubic Galilean-like term and a generic self-interaction, as a candidate of a Dark Energy model. The system is dynamically analyzed and novel fixed points with perturbative stability are demonstrated. Evolution of the system is numerically studied near a novel fixed point which owes its existence to the Galileon character of the model. It turns out that demanding the stability of this novel fixed point puts a strong restriction on the allowed non-minimal coupling and the choice of the self-interaction. The evolution of the equation of state parameter is studied, which shows that our model predicts an accelerated universe throughout and the phantom limit is only approached closely but never crossed. Our result thus extends the findings of Coley, Dynamical systems and cosmology. Kluwer Academic Publishers, Boston (2013) for more general NMC than linear and quadratic couplings.

An antithetic variate to facilitate upper-stem height measurements for critical height sampling with importance sampling

Treesearch

Thomas B. Lynch; Jeffrey H. Gove

2013-01-01

Critical height sampling (CHS) estimates cubic volume per unit area by multiplying the sum of critical heights measured on trees tallied in a horizontal point sample (HPS) by the HPS basal area factor. One of the barriers to practical application of CHS is the fact that trees near the field location of the point-sampling sample point have critical heights that occur...

Emission properties of body-centered cubic elemental metal photocathodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tuo; Rickman, Benjamin L., E-mail: brickm2@uic.edu; Schroeder, W. Andreas

2015-04-07

A first principles analysis of photoemission is developed to explain the lower than expected rms transverse electron momentum measured using the solenoid scan technique for the body-centered cubic Group Vb (V, Nb, and Ta) and Group VIb (Cr, Mo, and W) metallic photocathodes. The density functional theory based analysis elucidates the fundamental role that the electronic band structure (and its dispersion) plays in determining the emission properties of solid-state photocathodes and includes evaluation of work function anisotropy using a thin-slab method.

The deviations of the Al6Li3Cu quasicrystal from icosahedral symmetry : a reminiscence of a cubic crystal

NASA Astrophysics Data System (ADS)

Donnadieu, Patricia

1994-05-01

The (Al6Li3Cu) (T2) quasicrystals are known to exhibit large deviations from the icosahedral symmetry. Series of electron diffraction patterns are used to investigate these imperfections in as-cast T, samples. A detailed analysis of the 5-fold and 3-fold symmetry diffraction patterns shows that they are compatible with the m3 point group instead of the m35 icosahedral group. This symmetry reduction is interprétéd as reminiscent of the cubic approximant phase (R-Al5Li3Cu) rather than of higher order approximant phases. This interpretation is supported by previous observations on crystal/quasicrystal phase transformation in the AlLiCu system. Les quasicristaux de phase T2(Al6Li3Cu) montrent d'importantes déviations à la symétrie icosaédrique. Ces imperfections sont mises en évidence par diffraction électronique dans des échantillons de phase T2 brut de coulée. Un examen détaillé des diagrammes de diffraction de symétrie d'ordre 3 et 5 révèle qu'ils sont compatibles avec le groupe ponctuel m3 au lieu du groupe de l'icosaèdre (m35). Cette réduction de symétrie est interprétée comme une réminiscence de la phase cubique approximante (R-Al5Li3Cu) et non l'apparition d'approximant d'ordre plus élevé. Cette interprétation est suggérée par des observations antérieures sur la transformation cristal/quasicristal dans le système AlLiCu.

Marginal states in a cubic autocatalytic reaction

NASA Astrophysics Data System (ADS)

Das, Debojyoti; Ghosh, Pushpita; Ray, Deb Shankar

2011-09-01

Marginal steady state belongs to a special class of states in nonlinear dynamics. To realize this state we consider a cubic autocatalytic reaction A + 2B → 3B in a continuous-stirred-tank-reactor, where the flow rate of the reactant A can be controlled to manipulate the dynamical behavior of the open system. We demonstrate that when the flow rate is weakly noisy the autocatalytic reaction admits of a steady state which is marginal in nature and is surrounded by infinite number of periodic trajectories. When the uncatalyzed reaction A → B is included in the reaction scheme, there exists a marginal steady state which is a critical state corresponding to the point of transition between the flow branch and the equilibrium branch, similar to gas-liquid critical point of transition. This state loses its stability in the weak noise limit.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engel, Edgar A., E-mail: eae32@cam.ac.uk; Needs, Richard J.; Monserrat, Bartomeu

Surface energies of hexagonal and cubic water ice are calculated using first-principles quantum mechanical methods, including an accurate description of anharmonic nuclear vibrations. We consider two proton-orderings of the hexagonal and cubic ice basal surfaces and three proton-orderings of hexagonal ice prism surfaces, finding that vibrations reduce the surface energies by more than 10%. We compare our vibrational densities of states to recent sum frequency generation absorption measurements and identify surface proton-orderings of experimental ice samples and the origins of characteristic absorption peaks. We also calculate zero point quantum vibrational corrections to the surface electronic band gaps, which range frommore » −1.2 eV for the cubic ice basal surface up to −1.4 eV for the hexagonal ice prism surface. The vibrational corrections to the surface band gaps are up to 12% smaller than for bulk ice.« less

Martensitic and austenitic transformations in core-surface cubic nanoparticles

NASA Astrophysics Data System (ADS)

Özüm, S.; Yalçın, O.; Erdem, R.; Bayrakdar, H.; Eker, H. N.

2015-01-01

As a continuation of our recently published work, we have used the pair approximation in Kikuchi version to investigate martensitic and austenitic transformations in homogeneous (HM) and composite (CM) cubic nanoparticles (CNPs) based on the Blume-Emery-Griffiths model. A single cubic nanoparticle made of a core surrounded by a surface is considered as shaped in two dimensional (2D) square arrays instead of hexagonal array. From the phase diagrams of HM and CM-CNPs it has been observed that the martensitic-austenitic transformations (MT-AT) occurred. The influence of the exchange coupling and single-ion anisotropy parameters in the model Hamiltonian on the MT-AT is studied and analyzed in comparison with the results for hexagonal nanoparticles. Significant changes of the phase transition points and hysteresis behaviours depending upon the particle structure have been discussed.

Study of liquid crystal space groups using controlled tilting with cryogenic transmission electron microscopy.

PubMed

Sagalowicz, Laurent; Acquistapace, Simone; Watzke, Heribert J; Michel, Martin

2007-11-20

We developed a method that enables differentiation between liquid crystalline-phase particles corresponding to different space groups. It consists of controlled tilting of the specimen to observe different orientations of the same particle using cryogenic transmission electron microscopy. This leads to the visualization of lattice planes (or reflections) that are present for a given structure and absent for the other one(s) and that give information on liquid crystalline structures and their space groups. In particular, we show that we can unambiguously distinguish among particles having the inverted micellar cubic (space group Fd(3)m, 227), the inverted bicontinuous gyroid (space group Ia(3)d, 230), the inverted bicontinuous diamond (space group Pn(3)m, 224), and the inverted bicontinuous primitive cubic structure (space group Im(3)m, 229).

Structural and electrochemical properties of nanostructured nickel silicides by reduction and silicification of high-surface-area nickel oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Xiao; Zhang, Bingsen; Li, Chuang

Graphical abstract: Nanostructured nickel silicides have been synthesized by reduction and silification of high-surface-area nickel oxide, and exhibited remarkably like-noble metal property, lower electric resistivity, and ferromagnetism at room temperature. Highlights: Black-Right-Pointing-Pointer NiSi{sub x} have been prepared by reduction and silification of high-surface-area NiO. Black-Right-Pointing-Pointer The structure of nickel silicides changed with increasing reaction temperature. Black-Right-Pointing-Pointer Si doping into nickel changed the magnetic properties of metallic nickel. Black-Right-Pointing-Pointer NiSi{sub x} have remarkably lower electric resistivity and like-noble metal property. -- Abstract: Nanostructured nickel silicides have been prepared by reduction and silicification of high-surface-area nickel oxide (145 m{sup 2} g{sup -1})more » produced via precipitation. The prepared materials were characterized by nitrogen adsorption, X-ray diffraction, thermal analysis, FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, magnetic and electrochemical measurements. The nickel silicide formation involves the following sequence: NiO (cubic) {yields} Ni (cubic) {yields} Ni{sub 2}Si (orthorhombic) {yields} NiSi (orthorhombic) {yields} NiSi{sub 2} (cubic), with particles growing from 13.7 to 21.3 nm. The nickel silicides are ferromagnetic at room temperature, and their saturation magnetization values change drastically with the increase of Si content. Nickel silicides have remarkably low electrical resistivity and noble metal-like properties because of a constriction of the Ni d band and an increase of the electronic density of states. The results suggest that such silicides are promising candidates as inexpensive yet functional materials for applications in electrochemistry as well as catalysis.« less

Pupil size stability of the cubic phase mask solution for presbyopia

NASA Astrophysics Data System (ADS)

Almaguer, Citlalli; Acosta, Eva; Arines, Justo

2018-01-01

Presbyopia correction involves different types of studies such as lens design, clinical study, and the development of objective metrics, such as the visual Strehl ratio. Different contact lens designs have been proposed for presbyopia correction, but performance depends on pupil diameter. We will analyze the potential use of a nonsymmetrical element, a cubic phase mask (CPM) solution, to develop a contact or intraocular lens whose performance is nearly insensitive to changes in pupil diameter. We will show the through focus optical transfer function of the proposed element for different pupil diameters ranging from 3 to 7 mm. Additionally, we will show the images obtained through computation and experiment for a group of eye charts with different visual acuities. Our results show that a CPM shaped as 7.07 μm*(Z33-Z3-3)-0.9 μm Z20 is a good solution for a range of clear vision with a visual acuity of at least 0.1 logMar from 0.4 to 6 m for pupil diameters in the 3- to 7-mm range. Our results appear to be a good starting point for further development and study of this kind of CPM solution for presbyopia.

The breakdown of the weakly-nonlinear regime for kinetic instabilities

NASA Astrophysics Data System (ADS)

Sanz-Orozco, David; Berk, Herbert; Wang, Ge

2017-10-01

The evolution of marginally-unstable waves that interact resonantly with populations of energetic particles is governed by a well-known cubic integro-differential equation for the mode amplitude. One of the outcomes predicted by the equation is the so-called ``explosive'' regime, where the amplitude grows indefinitely, eventually taking the equation outside of its domain of validity. Beyond this point, only full Vlasov simulations will accurately describe the evolution of the mode amplitude. In this work, we study the breakdown of the cubic equation in detail. We find that, while the cubic equation is still valid, the distribution function of the energetic particles locally flattens or ``folds'' in phase space. This feature is unexpected in view of the assumptions of the theory that are given in. We also derive fifth-order terms in the wave equation, which not only give us a more accurate description of the marginally-unstable modes, but they also allow us to predict the breakdown of the cubic equation. Our findings allow us to better understand the transition between weakly-nonlinear modes and the long-term chirping modes that ultimately emerge.

Aquifer-test data and borehole flow test results from monitoring well 16P52 at the South Trend development area number 1, McKinley County, New Mexico

USGS Publications Warehouse

Stevens, Ken

1984-01-01

Mobil Oil Corporation personnel have designated at least four sandstone intervals, A-D (top to bottom), on the single-point resistivity logs of wells drilled in the South Trend Development Area. This report presents time-drawdown data reported by Mobil Oil Corporation from singly (A or B or C or D sandstone interval) and multiply (A, B, C, and D sandstone Intervals) completed wells for the August 16-17, 1982 aquifer test at the South Trend Development Area Site 1. This report also describes the results of flowmeter and brine-injection tests by the U.S. Geological Survey in monitoring well 16P52. Well 16P52 is open to sandstone intervals A, B, C, and D. On July 26, 1982, water was injected at a rate of 1.43 cubic feet per minute above the A sandstone interval in well 16P52. Based on flowmeter data, the calculated rates of flow were 1.23 cubic feet per minute between the A and B sandstone intervals, 0.63 cubic foot per minute between the B and C sandstone intervals, and less than 0.17 cubic foot per minute between the C and D sandstone intervals. Based upon brine-slug-injection tests conducted during August 1982, the calculated flow rates between sandstone intervals A and B are as follows: 0.01 cubic foot per minute upward flow (B to A) about 5 hours after pumping began for the aquifer test; 0.004 cubic foot per minute upward flow (B to A) about 21 hours after pumping began; and 0.0 cubic foot per minute about 46 hours after the pump was turned off. All other brine-slug-injection tests measured no flow.

Pressure-induced phase transitions in the CdC r2S e4 spinel

NASA Astrophysics Data System (ADS)

Efthimiopoulos, I.; Liu, Z. T. Y.; Kucway, M.; Khare, S. V.; Sarin, P.; Tsurkan, V.; Loidl, A.; Wang, Y.

2016-11-01

We have conducted high-pressure x-ray diffraction and Raman spectroscopic studies on the CdC r2S e4 spinel at room temperature up to 42 GPa. We have resolved three structural transitions up to 42 GPa, i.e., the starting F d 3 ¯m phase transforms at ˜11 GPa into a tetragonal I 41/a m d structure, an orthorhombic distortion was observed at ˜15 GPa , whereas structural disorder initiates beyond 25 GPa. Our ab initio density functional theory studies successfully reproduced the observed crystalline-to-crystalline structural transitions. In addition, our calculations propose an antiferromagnetic ordering as a potential magnetic ground state for the high-pressure tetragonal and orthorhombic modifications, compared with the starting ferromagnetic phase. Furthermore, the computational results indicate that all phases remain insulating in their stability pressure range, with a direct-to-indirect band gap transition for the F d 3 ¯m phase taking place at 5 GPa. We attempted also to offer an explanation behind the peculiar first-order character of the F d 3 ¯m (cubic ) →I 41/a m d (tetragonal) transition observed for several relevant Cr spinels, i.e., the sizeable volume change at the transition point, which is not expected from space group symmetry considerations. We detected a clear correlation between the cubic-tetragonal transition pressures and the next-nearest-neighbor magnetic exchange interactions for the Cr-bearing sulfide and selenide members, a strong indication that the cubic-tetragonal transitions in these systems are principally governed by magnetic effects.

Appearance of singularities of optical fields under torsion of crystals containing threefold symmetry axes.

PubMed

Skab, Ihor; Vasylkiv, Yurij; Zapeka, Bohdan; Savaryn, Viktoriya; Vlokh, Rostyslav

2011-07-01

We present an analysis of the effect of torsion stresses on the spatial distribution of optical birefringence in crystals of different point symmetry groups. The symmetry requirements needed so that the optical beam carries dislocations of the phase front are evaluated for the case when the crystals are twisted and the beam closely corresponds to a plane wave. It is shown that the torsion stresses can produce screw-edge, pure screw, or pure edge dislocations of the phase front in the crystals belonging to cubic and trigonal systems. The conditions for appearance of canonical and noncanonical vortices in the conditions of crystal torsion are analyzed. © 2011 Optical Society of America

Crystal structure refinements of tetragonal (OH,F)-rich spessartine and henritermierite garnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antao, Sytle M.; Cruickshank, Laura A.

Cubic garnet (space group Ia\\overline 3 d) has the general formulaX 3Y 2Z 3O 12, whereX,YandZare cation sites. In the tetragonal garnet (space groupI4 1/acd), the corresponding cation sites areX1 andX2,Y, andZ1 andZ2. In both space groups only theYsite is the same. The crystal chemistry of a tetragonal (OH,F)-rich spessartine sample from Tongbei, near Yunxiao, Fujian Province, China, with composition X(Mn 2.82Fe^{2+}_{0.14}Ca 0.04) Σ3 Y{Al 1.95Fe^{3+}_{0.05}} Σ2 Z[(SiO 4) 2.61(O 4H 4) 0.28(F 4) 0.11] Σ3(Sps 94Alm 5Grs 1) was studied with single-crystal X-ray diffraction and space groupI4 1/acd. The deviation of the unit-cell parameters from cubic symmetry is smallmore » [a= 11.64463(1),c= 11.65481 (2) Å,c/a= 1.0009]. Point analyses and back-scattered electron images, obtained by electron-probe microanalysis, indicate a homogeneous composition. TheZ2 site is fully occupied, but theZ1 site contains vacancies. The occupiedZ1 andZ2 sites with Si atoms are surrounded by four O atoms, as in anhydrous cubic garnets. Pairs of split sites are O1 with F11 and O2 with O22. When theZ1 site is vacant, a larger [(O 2H 2)F 2] tetrahedron is formed by two OH and two F anions in the O22 and F11 sites, respectively. This [(O 2H 2)F 2] tetrahedron is similar to the O 4H 4tetrahedron in hydrogarnets. These results indicate ^{X}{{\\rm Mn}^ {2+}_{3}}\\,^{Y}{\\rm Al}_{2}^{Z}[({\\rm SiO}_{4})_{2}({\\rm O}_{2}{\\rm H}_{2})_{0.5}({\\rm F}_{2})_{0.5}]_{\\Sigma3} as a possible end member, which is yet unknown. The H atom that is bonded to the O22 site is not located because of the small number of OH groups. In contrast, tetragonal henritermierite, ideally ^{X}{\\rm Ca}_{3}\\,^{Y}{\\rm Mn}^{3+}_{2}\\,^{Z}[({\\rm SiO}_{4})_{2}({\\rm O}_{4}{\\rm H}_{4})_1]_{\\Sigma3}, has a vacantZ2 site that contains the O 4H 4tetrahedron. The H atom is bonded to an O3 atom [O3—H3 = 0.73 (2) Å]. Because of O2—Mn 3+—O2 Jahn–Teller elongation of the Mn 3+O 6octahedron, a weak hydrogen bond is formed to the under-bonded O2 atom. This causes a large deviation from cubic symmetry (c/a= 0.9534).« less

Simulations of floodflows on the White River in the vicinity of U.S. Highway 79 near Clarendon, Arkansas

USGS Publications Warehouse

Funkhouser, Jaysson E.; Barks, C. Shane

2003-01-01

A two-dimensional finite-element surface-water model was used to study the effects of the proposed modification to the U.S. Highway 79 corridor on flooding on the White River near Clarendon, Arkansas. The effects of floodflows were simulated for the following scenarios: existing, natural, and four proposed bridging alternatives. All of the scenarios were modeled with floods having the 5- and 100-year recurrence intervals (115,100 and 216,000 cubic feet per second). The simulated existing conditions included a 3,200-foot White River bridge located on the east side of the study area near Clarendon, Arkansas; a 3,700-foot First Old River bridge located 0.5 mile west of the White River bridge opening; and a 1,430-foot Roc Roe Bayou bridge located 1.6 mile west of the First Old River bridge. The simulated hypothetical natural conditions involved removing the U.S. Highway 79 and the Union Pacific Railroad embankments along the entire length of the flood plain. The primary purpose of model simulations for natural conditions was to calculate backwater data for the existing and proposed conditions. The four simulated hypothetical proposed alternatives involved a 1.8-mile White River bridge located on the east side of the study area near Clarendon, Arkansas, either a 1,400-foot relief bridge (Alternative 1) or a 1,545 relief bridge (Alternatives 2-4) located 0.25 mile west of the White River bridge opening, and three different Roc Roe Bayou bridge openings ranging from 1,540-3,475 feet in length located 0.9 mile west of the relief bridge (Alternatives 1-4). Simulation of the 5-year floodflow for the existing bridge openings indicates that about 57 percent (65,600 cubic feet per second) of flow was conveyed by the White River bridge, about 26 percent (29,900 cubic feet per second) by the First Old River bridge, and about 17 percent (19,600 cubic feet per second) by the Roc Roe Bayou bridge. Maximum depth-averaged point velocities for the White River, First Old River, and Roc Roe Bayou bridges were 3.6, 1.6, and 3.3 feet per second, respectively. For the 100-year floodflow, the simulation indicates that about 56 percent (123,100 cubic feet per second) of flow was conveyed by the White River bridge, about 26 percent (56,200 cubic feet per second) by the First Old River bridge, and about 19 percent (41,000 cubic feet per second) by the Roc Roe Bayou bridge. The maximum depth-averaged point velocities for the White River, First Old River, and Roc Roe Bayou bridges were 4.2, 2.2, and 4.1 feet per second, respectively. Simulation of the 5-year floodflow for the proposed U.S. Highway 79 alignment alternatives indicates that 76-78 percent (87,100-89,900 cubic feet per second) of the flow was conveyed by the proposed White River bridge, 6-7 percent (7,000-7,500 cubic feet per second) by the proposed relief bridge, and 13-16 percent (14,600-18,600 cubic feet per second) by the proposed Roc Roe Bayou bridge. For the 100-year floodflow, simulations predicted that 70-72 percent (151,200-155,600 cubic feet per second) of the flow was conveyed by the proposed White River bridge, 9-10 percent (19,800-20,700 cubic feet per second) by the proposed relief bridge, and 14-20 percent (30,700-43,000 cubic feet per second) by the proposed Roc Roe Bayou bridge.

Taper and volume equations for selected Appalachian hardwood species

Treesearch

A. Jeff Martin

1981-01-01

Coefficients for five taper/volume models are developed for 18 Appalachian hardwood species. Each model can be used to estimate diameter at any point on the bole, height to any preselected diameter, and cubic-foot volume between any two points on the bole. The resulting equations were tested on six sets of independent data and an evaluation of these tests is included,...

Spline-based procedures for dose-finding studies with active control

PubMed Central

Helms, Hans-Joachim; Benda, Norbert; Zinserling, Jörg; Kneib, Thomas; Friede, Tim

2015-01-01

In a dose-finding study with an active control, several doses of a new drug are compared with an established drug (the so-called active control). One goal of such studies is to characterize the dose–response relationship and to find the smallest target dose concentration d*, which leads to the same efficacy as the active control. For this purpose, the intersection point of the mean dose–response function with the expected efficacy of the active control has to be estimated. The focus of this paper is a cubic spline-based method for deriving an estimator of the target dose without assuming a specific dose–response function. Furthermore, the construction of a spline-based bootstrap CI is described. Estimator and CI are compared with other flexible and parametric methods such as linear spline interpolation as well as maximum likelihood regression in simulation studies motivated by a real clinical trial. Also, design considerations for the cubic spline approach with focus on bias minimization are presented. Although the spline-based point estimator can be biased, designs can be chosen to minimize and reasonably limit the maximum absolute bias. Furthermore, the coverage probability of the cubic spline approach is satisfactory, especially for bias minimal designs. © 2014 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. PMID:25319931

Microscale simulations of shock interaction with large assembly of particles for developing point-particle models

NASA Astrophysics Data System (ADS)

Thakur, Siddharth; Neal, Chris; Mehta, Yash; Sridharan, Prasanth; Jackson, Thomas; Balachandar, S.

2017-01-01

Micrsoscale simulations are being conducted for developing point-particle and other related models that are needed for the mesoscale and macroscale simulations of explosive dispersal of particles. These particle models are required to compute (a) instantaneous aerodynamic force on the particle and (b) instantaneous net heat transfer between the particle and the surrounding. A strategy for a sequence of microscale simulations has been devised that allows systematic development of the hybrid surrogate models that are applicable at conditions representative of the explosive dispersal application. The ongoing microscale simulations seek to examine particle force dependence on: (a) Mach number, (b) Reynolds number, and (c) volume fraction (different particle arrangements such as cubic, face-centered cubic (FCC), body-centered cubic (BCC) and random). Future plans include investigation of sequences of fully-resolved microscale simulations consisting of an array of particles subjected to more realistic time-dependent flows that progressively better approximate the actual problem of explosive dispersal. Additionally, effects of particle shape, size, and number in simulation as well as the transient particle deformation dependence on various parameters including: (a) particle material, (b) medium material, (c) multiple particles, (d) incoming shock pressure and speed, (e) medium to particle impedance ratio, (f) particle shape and orientation to shock, etc. are being investigated.

Phase stability and magnetic behavior of FeCrCoNiGe high-entropy alloy

NASA Astrophysics Data System (ADS)

Huang, Shuo; Vida, Ádám; Molnár, Dávid; Kádas, Krisztina; Varga, Lajos Károly; Holmström, Erik; Vitos, Levente

2015-12-01

We report an alternative FeCrCoNiGe magnetic material based on FeCrCoNi high-entropy alloy with Curie point far below the room temperature. Investigations are done using first-principles calculations and key experimental measurements. Results show that the equimolar FeCrCoNiGe system is decomposed into a mixture of face-centered cubic and body-centered cubic solid solution phases. The increased stability of the ferromagnetic order in the as-cast FeCrCoNiGe composite, with measured Curie temperature of 640 K, is explained using the exchange interactions.

Craniofacial Reconstruction Using Rational Cubic Ball Curves

PubMed Central

Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R. U.; Yahya, Zainor Ridzuan

2015-01-01

This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

Absence of metastable states in strained monoatomic cubic crystals.

NASA Astrophysics Data System (ADS)

Aguayo, Aarón; Mehl, Michael L.; de Coss, Romeo

2005-03-01

The Bain path distortion of a metal with an fcc (bcc) ground state toward the bcc (fcc) structure initially requires an increase in energy, but at some point along the Bain path the energy will again decrease until a local minimum is reached. We have studied the tetragonal distortion (Bain path) of monoatomic cubic crystals, using a combination of parametrized tight-binding and first-principles linearized augmented plane wave calculations. We show that this local minimum is unstable with respect to an elastic distortion, except in the rare case that the minimum is at the bcc (fcc) point on the Bain path. This shows that body-centered-tetragonal phases of these materials, which have been seen in epitaxially grown thin films, must be stabilized by the substrate and cannot be freestanding films. This work was partially supported by Consejo Nacional de Ciencia y Tecnolog'ia (CONACYT, M'exico) under Grant No. 43830-F.

Flow origin, drainage area, and hydrologic characteristics for headwater streams in the mountaintop coal-mining region of Southern West Virginia, 2000-01

USGS Publications Warehouse

Paybins, Katherine S.

2003-01-01

Characteristics of perennial and intermittent headwater streams were documented in the mountaintop removal coal-mining region of southern West Virginia in 2000?01. The perennial-flow origin points were identified in autumn during low base-flow conditions. The intermittent-flow origin points were identified in late winter and early spring during high base-flow conditions. Results of this investigation indicate that the median drainage area upstream of the origin of intermittent flow was 14.5 acres, and varied by an absolute median of 3.4 acres between the late winter measurements of 2000 and early spring measurements of 2001. Median drainage area in the northeastern part of the study unit was generally larger (20.4 acres), with a lower median basin slope (322 feet per mile) than the southwestern part of the study unit (12.9 acres and 465 feet per mile, respectively). Both of the seasons preceding the annual intermittent flow visits were much drier than normal. The West Virginia Department of Environmental Protection reports that the median size of permitted valley fills in southern West Virginia is 12.0 acres, which is comparable to the median drainage area upstream of the ephemeralintermittent flow point (14.5 acres). The maximum size of permitted fills (480 acres), however, is more than 10 times the observed maximum drainage area upstream of the ephemeral-intermittent flow point (45.3 acres), although a single valley fill may cover more than one drainage area. The median drainage area upstream of the origin of perennial flow was 40.8 acres, and varied by an absolute median of 18.0 acres between two annual autumn measurements. Only basins underlain with mostly sandstone bedrock produced perennial flow. Perennial points in the northeast part of the study unit had a larger median drainage area (70.0 acres) and a smaller median basin slope (416 feet per mile) than perennial points in the southwest part of the study unit (35.5 acres and 567 feet per mile, respectively). Some streams were totally dry for one or both of the annual October visits. Both of the seasons preceding the October visits had near normal to higher than normal precipitation. These dry streams were adjacent to perennial streams draining similarly sized areas, suggesting that local conditions at a firstorder- stream scale determine whether or not there will be perennial flow. Headwater-flow rates varied little from year to year, but there was some variation between late winter and early spring and autumn. Flow rates at intermittent points of flow origin ranged from 0.001 to 0.032 cubic feet per second, with a median of 0.017 cubic feet per second. Flow rates at perennial points of flow origin ranged from 0.001 to 0.14 cubic feet per second, with a median of 0.003 cubic feet per second.

Predicted Realization of Cubic Dirac Fermion in Quasi-One-Dimensional Transition-Metal Monochalcogenides

NASA Astrophysics Data System (ADS)

Liu, Qihang; Zunger, Alex

2017-04-01

We show that the previously predicted "cubic Dirac fermion," composed of six conventional Weyl fermions including three with left-handed and three with right-handed chirality, is realized in a specific, stable solid state system that has been made years ago, but was not appreciated as a "cubically dispersed Dirac semimetal" (CDSM). We identify the crystal symmetry constraints and find the space group P 63/m as one of the two that can support a CDSM, of which the characteristic band crossing has linear dispersion along the principle axis but cubic dispersion in the plane perpendicular to it. We then conduct a material search using density functional theory, identifying a group of quasi-one-dimensional molybdenum monochalcogenide compounds AI(MoXVI)3 (AI=Na , K, Rb, In, Tl; XVI=S , Se, Te) as ideal CDSM candidates. Studying the stability of the A (MoX) 3 family reveals a few candidates such as Rb (MoTe) 3 and Tl (MoTe) 3 that are predicted to be resilient to Peierls distortion, thus retaining the metallic character. Furthermore, the combination of one dimensionality and metallic nature in this family provides a platform for unusual optical signature—polarization-dependent metallic vs insulating response.

Interactive algebraic grid-generation technique

NASA Technical Reports Server (NTRS)

Smith, R. E.; Wiese, M. R.

1986-01-01

An algebraic grid generation technique and use of an associated interactive computer program are described. The technique, called the two boundary technique, is based on Hermite cubic interpolation between two fixed, nonintersecting boundaries. The boundaries are referred to as the bottom and top, and they are defined by two ordered sets of points. Left and right side boundaries which intersect the bottom and top boundaries may also be specified by two ordered sets of points. when side boundaries are specified, linear blending functions are used to conform interior interpolation to the side boundaries. Spacing between physical grid coordinates is determined as a function of boundary data and uniformly space computational coordinates. Control functions relating computational coordinates to parametric intermediate variables that affect the distance between grid points are embedded in the interpolation formulas. A versatile control function technique with smooth-cubic-spline functions is presented. The technique works best in an interactive graphics environment where computational displays and user responses are quickly exchanged. An interactive computer program based on the technique and called TBGG (two boundary grid generation) is also described.

Vibrational renormalisation of the electronic band gap in hexagonal and cubic ice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engel, Edgar A., E-mail: eae32@cam.ac.uk; Needs, Richard J.; Monserrat, Bartomeu

2015-12-28

Electron-phonon coupling in hexagonal and cubic water ice is studied using first-principles quantum mechanical methods. We consider 29 distinct hexagonal and cubic ice proton-orderings with up to 192 molecules in the simulation cell to account for proton-disorder. We find quantum zero-point vibrational corrections to the minimum electronic band gaps ranging from −1.5 to −1.7 eV, which leads to improved agreement between calculated and experimental band gaps. Anharmonic nuclear vibrations play a negligible role in determining the gaps. Deuterated ice has a smaller band-gap correction at zero-temperature of −1.2 to −1.4 eV. Vibrations reduce the differences between the electronic band gapsmore » of different proton-orderings from around 0.17 eV to less than 0.05 eV, so that the electronic band gaps of hexagonal and cubic ice are almost independent of the proton-ordering when quantum nuclear vibrations are taken into account. The comparatively small reduction in the band gap over the temperature range 0 − 240 K of around 0.1 eV does not depend on the proton ordering, or whether the ice is protiated or deuterated, or hexagonal, or cubic. We explain this in terms of the atomistic origin of the strong electron-phonon coupling in ice.« less

Implementation and Operational Research: CD4 Count Monitoring Frequency and Risk of CD4 Count Dropping Below 200 Cells Per Cubic Millimeter Among Stable HIV-Infected Patients in New York City, 2007-2013.

PubMed

Myers, Julie E; Xia, Qiang; Torian, Lucia V; Irvine, Mary; Harriman, Graham; Sepkowitz, Kent A; Shepard, Colin W

2016-03-01

The evidence has begun to mount for diminishing the frequency of CD4 count testing. To determine whether these observations were applicable to an urban US population, we used New York City (NYC) surveillance data to explore CD4 testing among stable patients in NYC, 2007-2013. We constructed a population-based retrospective open cohort analysis of NYC HIV surveillance data. HIV+ patients aged ≥ 13 years with stable viral suppression (≥ 1 viral load the previous year; all <400 copies per milliliter) and immune status (≥ 1 CD4 the previous year; all ≥ 200 cells per cubic millimeter) entered the cohort the following year beginning January 1, 2007. Each subsequent year, eligible patients not previously included entered the cohort on January 1. Outcomes were annual frequency of CD4 monitoring and probability of maintaining CD4 ≥ 200 cells per cubic millimeter. A multivariable Cox model identified factors associated with maintaining CD4 ≥ 200 cells per cubic millimeter. During 1.9 years of observation (median), 62,039 patients entered the cohort. The mean annual number of CD4 measurements among stable patients was 2.8 and varied little by year or characteristic. Two years after entering, 93.4% and 97.8% of those with initial CD4 350-499 and CD4 ≥ 500 cells per cubic millimeter, respectively, maintained CD4 ≥ 200 cells per cubic millimeter. Compared to those with initial CD4 ≥ 500 cells per cubic millimeter, those with CD4 200-349 cells per cubic millimeter and CD4 350-499 cells per cubic millimeter were more likely to have a CD4 <200 cells per cubic millimeter, controlling for sex, race, age, HIV risk group, and diagnosis year. In a population-based US cohort with well-controlled HIV, the probability of maintaining CD4 ≥ 200 cells per cubic millimeter for ≥ 2 years was >90% among those with initial CD4 ≥ 350 cells per cubic millimeter, suggesting that limited CD4 monitoring in these patients is appropriate.

Crystal Structure of Garnet-Related Li-Ion Conductor Li7–3xGaxLa3Zr2O12: Fast Li-Ion Conduction Caused by a Different Cubic Modification?

PubMed Central

2016-01-01

Li-oxide garnets such as Li7La3Zr2O12 (LLZO) are among the most promising candidates for solid-state electrolytes to be used in next-generation Li-ion batteries. The garnet-structured cubic modification of LLZO, showing space group Ia-3d, has to be stabilized with supervalent cations. LLZO stabilized with Ga3+ shows superior properties compared to LLZO stabilized with similar cations; however, the reason for this behavior is still unknown. In this study, a comprehensive structural characterization of Ga-stabilized LLZO is performed by means of single-crystal X-ray diffraction. Coarse-grained samples with crystal sizes of several hundred micrometers are obtained by solid-state reaction. Single-crystal X-ray diffraction results show that Li7–3xGaxLa3Zr2O12 with x > 0.07 crystallizes in the acentric cubic space group I-43d. This is the first definite record of this cubic modification for LLZO materials and might explain the superior electrochemical performance of Ga-stabilized LLZO compared to its Al-stabilized counterpart. The phase transition seems to be caused by the site preference of Ga3+. 7Li NMR spectroscopy indicates an additional Li-ion diffusion process for LLZO with space group I-43d compared to space group Ia-3d. Despite all efforts undertaken to reveal structure–property relationships for this class of materials, this study highlights the potential for new discoveries. PMID:27019548

Process for producing wurtzitic or cubic boron nitride

DOEpatents

Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

1992-04-28

Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

Process for producing wurtzitic or cubic boron nitride

DOEpatents

Holt, J. Birch; Kingman, deceased, Donald D.; Bianchini, Gregory M.

1992-01-01

Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

Floods of July 19-25, 1999, in the Wapsipinicon and Cedar River basins, northeast Iowa

USGS Publications Warehouse

Ballew, J.L.; Eash, D.A.

2001-01-01

Severe flooding occurred during July 19-25, 1999, in the Wapsipinicon and Cedar River Basins following two thunderstorms over northeast Iowa. During July 18-19, as much as 6 inches of rainfall was centered over Cerro Gordo, Floyd, Mitchell, and Worth Counties. During July 20-21, a second storm occurred in which an additional rainfall of as much as 8 inches was centered over Chickasaw and Floyd Counties. The cumulative effect of the storms produced floods with new maximum peak discharges at the following streamflow-gaging stations: Wapsipinicon River near Tripoli, 19,400 cubic feet per second; Cedar River at Charles City, 31,200 cubic feet per second (recurrence interval about 90 years); Cedar River at Janesville, 42,200 cubic feet per second (recurrence interval about 80 years); and Flood Creek near Powersville, 19,000 cubic feet per second. Profiles of flood elevations for the July 1999 flood are presented in this report for selected reaches along the Wapsipinicon, Cedar, and Shell Rock Rivers and along Flood Creek. Information about the river basins, rain storms, and flooding are presented along with information on temporary bench marks and reference points in the Wapsipinicon and Cedar River Basins.

Stem Cubic-Foot Volume Tables for Tree Species in the Piedmont

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 16 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Piedmont. Tables are based on form class measurement data for 2,753 trees sampled in the Piedmont and taper data collected across the South. A series of tables is presented for each species...

Stem Cubic-Foot Volume Tables for Tree Species in the Upper Coastal Plain

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 11 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Upper Coastal Plain. Tables are based on form class measurement data for 521 trees sampled in the Upper Coastal Plain and taper data collected across the South. A series of tables is...

Stem Cubic-Foot Volume Tables for Tree Species in the Appalachian Area

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 20 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Appalachian Area. Tables are based on form class measurement data for 2,870 trees sampled in the Appalachian Area and taper data collected across the South. A series of tables is presented...

Assessment of undiscovered oil and gas resources in sandstone reservoirs of the Cotton Valley Group, U.S. Gulf Coast, 2015

USGS Publications Warehouse

Eoff, Jennifer D.; Biewick, Laura R.H.; Brownfield, Michael E.; Burke, Lauri; Charpentier, Ronald R.; Dubiel, Russell F.; Gaswirth, Stephanie B.; Gianoutsos, Nicholas J.; Kinney, Scott A.; Klett, Timothy R.; Leathers, Heidi M.; Mercier, Tracey J.; Paxton, Stanley T.; Pearson, Ofori N.; Pitman, Janet K.; Schenk, Christopher J.; Tennyson, Marilyn E.; Whidden, Katherine J.

2015-08-11

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered mean volumes of 14 million barrels of conventional oil, 430 billion cubic feet of conventional gas, 34,028 billion cubic feet of continuous gas, and a mean total of 391 million barrels of natural gas liquids in sandstone reservoirs of the Upper Jurassic–Lower Cretaceous Cotton Valley Group in onshore lands and State waters of the U.S. Gulf Coast region.

Photonic band gap templating using optical interference lithography

NASA Astrophysics Data System (ADS)

Chan, Timothy Y. M.; Toader, Ovidiu; John, Sajeev

2005-04-01

We describe the properties of three families of inversion-symmetric, large photonic band-gap (PBG) template architectures defined by iso-intensity surfaces in four beam laser interference patterns. These templates can be fabricated by optical interference (holographic) lithography in a suitable polymer photo-resist. PBG materials can be synthesized from these templates using two stages of infiltration and inversion, first with silica and second with silicon. By considering point and space group symmetries to produce laser interference patterns with the smallest possible irreducible Brillouin zones, we obtain laser beam intensities, directions, and polarizations which generate a diamond-like (fcc) crystal, a novel body-centered cubic (bcc) architecture, and a simple-cubic (sc) structure. We obtain laser beam parameters that maximize the intensity contrasts of the interference patterns. This optimizes the robustness of the holographic lithography to inhomogeneity in the polymer photo-resist. When the optimized iso-intensity surface defines a silicon to air boundary (dielectric contrast of 11.9 to 1), the fcc, bcc, and sc crystals have PBG to center frequency ratios of 25%, 21%, and 11%, respectively. A full PBG forms for the diamond-like crystal when the refractive index contrast exceeds 1.97 to 1. We illustrate a noninversion symmetric PBG architecture that interpolates between a simple fcc structure and a diamond network structure. This crystal exhibits two distinct and complete photonic band gaps. We also describe a generalized class of tetragonal photonic crystals that interpolate between and extrapolate beyond the diamond-like crystal and the optimized bcc crystal. We demonstrate the extent to which the resulting PBG materials are robust against perturbations to the laser beam amplitudes and polarizations, and template inhomogeneity. The body centered cubic structure exhibits the maximum robustness overall.

Pattern formation in three-dimensional reaction-diffusion systems

NASA Astrophysics Data System (ADS)

Callahan, T. K.; Knobloch, E.

1999-08-01

Existing group theoretic analysis of pattern formation in three dimensions [T.K. Callahan, E. Knobloch, Symmetry-breaking bifurcations on cubic lattices, Nonlinearity 10 (1997) 1179-1216] is used to make specific predictions about the formation of three-dimensional patterns in two models of the Turing instability, the Brusselator model and the Lengyel-Epstein model. Spatially periodic patterns having the periodicity of the simple cubic (SC), face-centered cubic (FCC) or body-centered cubic (BCC) lattices are considered. An efficient center manifold reduction is described and used to identify parameter regimes permitting stable lamellæ, SC, FCC, double-diamond, hexagonal prism, BCC and BCCI states. Both models possess a special wavenumber k* at which the normal form coefficients take on fixed model-independent ratios and both are described by identical bifurcation diagrams. This property is generic for two-species chemical reaction-diffusion models with a single activator and inhibitor.

A topological coordinate system for the diamond cubic grid.

PubMed

Čomić, Lidija; Nagy, Benedek

2016-09-01

Topological coordinate systems are used to address all cells of abstract cell complexes. In this paper, a topological coordinate system for cells in the diamond cubic grid is presented and some of its properties are detailed. Four dependent coordinates are used to address the voxels (triakis truncated tetrahedra), their faces (hexagons and triangles), their edges and the points at their corners. Boundary and co-boundary relations, as well as adjacency relations between the cells, can easily be captured by the coordinate values. Thus, this coordinate system is apt for implementation in various applications, such as visualizations, morphological and topological operations and shape analysis.

Cubic polynomial maps with periodic critical orbit, Part II

NASA Astrophysics Data System (ADS)

Bonifant, Araceli; Kiwi, Jan; Milnor, John

The parameter space S_p for monic centered cubic polynomial maps with a marked critical point of period p is a smooth affine algebraic curve whose genus increases rapidly with p . Each S_p consists of a compact connectedness locus together with finitely many escape regions, each of which is biholomorphic to a punctured disk and is characterized by an essentially unique Puiseux series. This note will describe the topology of S_p , and of its smooth compactification, in terms of these escape regions. In particular, it computes the Euler characteristic. It concludes with a discussion of the real sub-locus of S_p .

A Field Trial to Assess a Blood-Stage Malaria Vaccine

PubMed Central

Thera, Mahamadou A.; Doumbo, Ogobara K.; Coulibaly, Drissa; Laurens, Matthew B.; Ouattara, Amed; Kone, Abdoulaye K.; Guindo, Ando B.; Traore, Karim; Traore, Idrissa; Kouriba, Bourema; Diallo, Dapa A.; Diarra, Issa; Daou, Modibo; Dolo, Amagana; Tolo, Youssouf; Sissoko, Mahamadou S.; Niangaly, Amadou; Sissoko, Mady; Takala-Harrison, Shannon; Lyke, Kirsten E.; Wu, Yukun; Blackwelder, William C.; Godeaux, Olivier; Vekemans, Johan; Dubois, Marie-Claude; Ballou, W. Ripley; Cohen, Joe; Thompson, Darby; Dube, Tina; Soisson, Lorraine; Diggs, Carter L.; House, Brent; Lanar, David E.; Dutta, Sheetij; Heppner, D. Gray; Plowe, Christopher V.

2011-01-01

BACKGROUND Blood-stage malaria vaccines are intended to prevent clinical disease. The malaria vaccine FMP2.1/AS02A, a recombinant protein based on apical membrane antigen 1 (AMA1) from the 3D7 strain of Plasmodium falciparum, has previously been shown to have immunogenicity and acceptable safety in Malian adults and children. METHODS In a double-blind, randomized trial, we immunized 400 Malian children with either the malaria vaccine or a control (rabies) vaccine and followed them for 6 months. The primary end point was clinical malaria, defined as fever and at least 2500 parasites per cubic millimeter of blood. A secondary end point was clinical malaria caused by parasites with the AMA1 DNA sequence found in the vaccine strain. RESULTS The cumulative incidence of the primary end point was 48.4% in the malaria-vaccine group and 54.4% in the control group; efficacy against the primary end point was 17.4% (hazard ratio for the primary end point, 0.83; 95% confidence interval [CI], 0.63 to 1.09; P = 0.18). Efficacy against the first and subsequent episodes of clinical malaria, as defined on the basis of various parasite-density thresholds, was approximately 20%. Efficacy against clinical malaria caused by parasites with AMA1 corresponding to that of the vaccine strain was 64.3% (hazard ratio, 0.36; 95% CI, 0.08 to 0.86; P = 0.03). Local reactions and fever after vaccination were more frequent with the malaria vaccine. CONCLUSIONS On the basis of the primary end point, the malaria vaccine did not provide significant protection against clinical malaria, but on the basis of secondary results, it may have strain-specific efficacy. If this finding is confirmed, AMA1 might be useful in a multicomponent malaria vaccine. PMID:21916638

Coated conductors

DOEpatents

Arendt, Paul N.; Foltyn, Stephen R.; Stan, Liliana; Usov, Igor O.; Wang, Haiyan

2010-06-15

Articles are provided including a base substrate having a layer of an IBAD oriented material thereon, and, a layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the layer of an IBAD oriented material. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates.

A Collection of Technical Studies Completed for the Computer-Aided Acquisition and Logistic Support (CALS) Program Fiscal Year 1988. Volume 3. CGM Registration

DTIC Science & Technology

1991-03-01

the array are used cyclically, that is when the end of the array is reached, the pattern starts over at the beginning. Dashed lines wrap around curves...the dash pattern relative to the start of the path. It is interpreted as a .distance into the dash pattern at which the pattern should be started ...cubic seldom Is drawn using the four points specified. The curve starts at the first point and ends at the fourth point; the second and third point are

Stem Cubic-Volume Tables for Tree Species in the Deep South Area

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 21 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Deep South Area. Tables are based on form class measurement data for 2,390 trees sampled in the Deep South Area and taper data collected across the South. A series of tables is presented for...

Stem Cubic-Foot Volume Tables for Tree Species in the Arkansas Area

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 9 species and 6 species groups based on equations used to estimate timber sale volumes on national forests in the Arkansas Area. Tables are based on form class measurement data for 1,417 trees sampled in the Arkansas Area and taper data collected across the South. A series of tables is presented for each...

Stem Cubic-Foot Volume Tables for Tree Species in the South

Treesearch

Alexander Clark; Ray A. Souter

1994-01-01

Stemwood cubic-foot volume tables were presented for 44 species and 10 species groups based on equations used to estimate timber sale volumes on national forests in the South. Tables are based on taper data for 13,469 trees sampled from Virginia to Texas. A series of tables are presented for each species based on diameter at breast height (d.b.h.) in combination with...

Stem Cubic-Foot Volume Tables for Tree Species in the Gulf and Atlantic Coastal Plain

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 14 species and 9 species groups based on equations used to estimate timber sale volumes on national forests in the Gulf and Atlantic Coastal Plain. Tables are based on form class measurement data for 2,728 trees sampled in the Gulf and Atlantic Coastal Plain and taper data collected across the South. A...

Stem Cubic-Foot Volume Tabies for Tree Species in the Delta Area

Treesearch

Alexander Clark; Ray A. Souter

1996-01-01

Stemwood cubic-foot volume inside bark tables are presented for 13 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Delta Area. Tables are based on form class measurement data for 990 trees sampled in the Delta Area and taper data collected across the South. A series of tables is presented for each species...

Predicted Realization of Cubic Dirac Fermion in Quasi-One-Dimensional Transition-Metal Monochalcogenides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Qihang; Zunger, Alex

We show that the previously predicted “cubic Dirac fermion,” composed of six conventional Weyl fermions including three with left-handed and three with right-handed chirality, is realized in a specific, stable solid state system that has been made years ago, but was not appreciated as a “cubically dispersed Dirac semimetal” (CDSM). We identify the crystal symmetry constraints and find the space group P6 3/m as one of the two that can support a CDSM, of which the characteristic band crossing has linear dispersion along the principle axis but cubic dispersion in the plane perpendicular to it. We then conduct a materialmore » search using density functional theory, identifying a group of quasi-one-dimensional molybdenum monochalcogenide compounds A I(MoX VI) 3 (AI = Na, K, Rb, In, Tl; X VI = S , Se, Te) as ideal CDSM candidates. Studying the stability of the A ( MoX ) 3 family reveals a few candidates such as Rb(MoTe) 3 and Tl(MoTe) 3 that are predicted to be resilient to Peierls distortion, thus retaining the metallic character. Furthermore, the combination of one dimensionality and metallic nature in this family provides a platform for unusual optical signature—polarization-dependent metallic vs insulating response.« less

Predicted Realization of Cubic Dirac Fermion in Quasi-One-Dimensional Transition-Metal Monochalcogenides

DOE PAGES

Liu, Qihang; Zunger, Alex

2017-05-09

We show that the previously predicted “cubic Dirac fermion,” composed of six conventional Weyl fermions including three with left-handed and three with right-handed chirality, is realized in a specific, stable solid state system that has been made years ago, but was not appreciated as a “cubically dispersed Dirac semimetal” (CDSM). We identify the crystal symmetry constraints and find the space group P6 3/m as one of the two that can support a CDSM, of which the characteristic band crossing has linear dispersion along the principle axis but cubic dispersion in the plane perpendicular to it. We then conduct a materialmore » search using density functional theory, identifying a group of quasi-one-dimensional molybdenum monochalcogenide compounds A I(MoX VI) 3 (AI = Na, K, Rb, In, Tl; X VI = S , Se, Te) as ideal CDSM candidates. Studying the stability of the A ( MoX ) 3 family reveals a few candidates such as Rb(MoTe) 3 and Tl(MoTe) 3 that are predicted to be resilient to Peierls distortion, thus retaining the metallic character. Furthermore, the combination of one dimensionality and metallic nature in this family provides a platform for unusual optical signature—polarization-dependent metallic vs insulating response.« less

Defect Genome of Cubic Perovskites for Fuel Cell Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balachandran, Janakiraman; Lin, Lianshan; Anchell, Jonathan S.

Heterogeneities such as point defects, inherent to material systems, can profoundly influence material functionalities critical for numerous energy applications. This influence in principle can be identified and quantified through development of large defect data sets which we call the defect genome, employing high-throughput ab initio calculations. However, high-throughput screening of material models with point defects dramatically increases the computational complexity and chemical search space, creating major impediments toward developing a defect genome. In this paper, we overcome these impediments by employing computationally tractable ab initio models driven by highly scalable workflows, to study formation and interaction of various point defectsmore » (e.g., O vacancies, H interstitials, and Y substitutional dopant), in over 80 cubic perovskites, for potential proton-conducting ceramic fuel cell (PCFC) applications. The resulting defect data sets identify several promising perovskite compounds that can exhibit high proton conductivity. Furthermore, the data sets also enable us to identify and explain, insightful and novel correlations among defect energies, material identities, and defect-induced local structural distortions. Finally, such defect data sets and resultant correlations are necessary to build statistical machine learning models, which are required to accelerate discovery of new materials.« less

Defect Genome of Cubic Perovskites for Fuel Cell Applications

DOE PAGES

Balachandran, Janakiraman; Lin, Lianshan; Anchell, Jonathan S.; ...

2017-10-10

Heterogeneities such as point defects, inherent to material systems, can profoundly influence material functionalities critical for numerous energy applications. This influence in principle can be identified and quantified through development of large defect data sets which we call the defect genome, employing high-throughput ab initio calculations. However, high-throughput screening of material models with point defects dramatically increases the computational complexity and chemical search space, creating major impediments toward developing a defect genome. In this paper, we overcome these impediments by employing computationally tractable ab initio models driven by highly scalable workflows, to study formation and interaction of various point defectsmore » (e.g., O vacancies, H interstitials, and Y substitutional dopant), in over 80 cubic perovskites, for potential proton-conducting ceramic fuel cell (PCFC) applications. The resulting defect data sets identify several promising perovskite compounds that can exhibit high proton conductivity. Furthermore, the data sets also enable us to identify and explain, insightful and novel correlations among defect energies, material identities, and defect-induced local structural distortions. Finally, such defect data sets and resultant correlations are necessary to build statistical machine learning models, which are required to accelerate discovery of new materials.« less

Thermal evolution of the metastable r8 and bc8 polymorphs of silicon

DOE PAGES

Haberl, Bianca; Guthrie, Malcolm; Sinogeikin, Stanislav V.; ...

2015-01-28

The kinetics of two metastable polymorphs of silicon under thermal annealing was investigated. These phases with body-centered cubic bc8 and rhombohedral r8 structures can be formed upon pressure release from metallic silicon.We study these metastable polymorphs were formed by two different methods, via point loading and in a diamond anvil cell (DAC). Upon thermal annealing different transition pathways were detected. In the point loading case, the previously reported Si-XIII formed and was confirmed as a new phase with an as-yet-unidentified structure. In the DAC case, bc8-Si transformed to the hexagonal-diamond structure at elevated pressure, consistent with previous studies at ambientmore » pressure. In contrast, r8-Si transformed directly to diamond-cubic Si at a temperature of 255⁰C. In conclusion, these data were used to construct diagrams of the metastability regimes of the polymorphs formed in a DAC and may prove useful for potential technological applications of these metastable polymorphs.« less

Thermal evolution of the metastable r8 and bc8 polymorphs of silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haberl, Bianca; Guthrie, Malcolm; Sinogeikin, Stanislav V.

The kinetics of two metastable polymorphs of silicon under thermal annealing was investigated. These phases with body-centered cubic bc8 and rhombohedral r8 structures can be formed upon pressure release from metallic silicon.We study these metastable polymorphs were formed by two different methods, via point loading and in a diamond anvil cell (DAC). Upon thermal annealing different transition pathways were detected. In the point loading case, the previously reported Si-XIII formed and was confirmed as a new phase with an as-yet-unidentified structure. In the DAC case, bc8-Si transformed to the hexagonal-diamond structure at elevated pressure, consistent with previous studies at ambientmore » pressure. In contrast, r8-Si transformed directly to diamond-cubic Si at a temperature of 255⁰C. In conclusion, these data were used to construct diagrams of the metastability regimes of the polymorphs formed in a DAC and may prove useful for potential technological applications of these metastable polymorphs.« less

Water quality and streamflow gains and losses of Osage and Prairie Creeks, Benton County, Arkansas, July 2001

USGS Publications Warehouse

Moix, Matthew W.; Barks, C. Shane; Funkhouser, Jaysson E.

2003-01-01

Osage and Prairie Creeks in Benton County, Arkansas, were studied between July 24 and July 26, 2001, to describe the surface-water quality and the streamflow gains and losses along sections of each mainstem. The creeks are located in northwestern Arkansas. Water-quality samples were collected at 12 surface-water sites on the mainstem and at 6 points of inflow for Osage Creek, and at 9 surface-water sites on the mainstem and at 4 points of inflow for Prairie Creek. Water-quality analyses were performed by Rogers Water Utilities and the Arkansas Water Resources Laboratory. Streamflow measurements were made along the mainstem of each creek and at points of inflow (prior to confluence with the mainstem) to identify gaining and losing reaches. Water-quality data collected for Osage Creek indicated that dissolved ammonia concentrations were within the typical range of concentrations measured for streams in the Springfield and Salem Plateaus. Nitrite plus nitrate and total phosphorus concentrations were within the range of concentrations measured for several streams in the western part of the Springfield and Salem Plateaus. Total phosphorus concentrations measured on the mainstem of Osage Creek were higher downstream from the Rogers wastewater-treatment plant than upstream from the wastewater-treatment plant. Water-quality data collected for Prairie Creek indicated that dissolved ammonia concentrations measured for three mainstem sites were above the typical level of dissolved ammonia concentrations measured for streams in the Springfield and Salem Plateaus. High concentrations of dissolved ammonia measured at these sites might be indicative of sewage disposal or organic waste. Most concentrations of nitrite plus nitrate for Prairie Creek were above the range measured for some of the least-disturbed streams of the Ozark Highlands ecoregion but were within the range that is typical for several streams in the western part of the Springfield and Salem Plateaus. Total phosphorus concentrations were below or within the range that is typical for several streams in the western part of the Springfield and Salem Plateaus with elevated concentrations measured at two sties. Elevated concentrations of total phosphorus measured might be indicative of sewage or animal metabolic waste. Identification of losing and gaining reaches indicates that interaction exists between the local shallow unconfined ground-water aquifer and surface flow in Osage and Prairie Creeks. Measured streamflow for the mainstem of Osage Creek ranged from 2.34 to 19.1 cubic feet per second during this study. Streamflow measured at the beginning of the study reach for Osage Creek was 2.34 cubic feet per second, and streamflow measured at the downstream end of the study reach was 15.7 cubic feet per second. One losing and two gaining reaches were identified on the mainstem of Osage Creek with a net gain of 3.58 cubic feet per second upstream from the wastewater-treatment plant. Measured streamflow for the mainstem of Prairie Creek ranged from 0 to 3.17 cubic feet per second during this study. Streamflow measured at the beginning of the study reach for Prairie Creek was 0.44 cubic feet per second, and the stream bed was dry at the downstream end of the study reach. Three losing and two gaining reaches were identified on the mainstem of Prairie Creek with a net loss of 3.06 cubic feet per second.

Adaptation of a cubic smoothing spline algortihm for multi-channel data stitching at the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, C; Adcock, A; Azevedo, S

2010-12-28

Some diagnostics at the National Ignition Facility (NIF), including the Gamma Reaction History (GRH) diagnostic, require multiple channels of data to achieve the required dynamic range. These channels need to be stitched together into a single time series, and they may have non-uniform and redundant time samples. We chose to apply the popular cubic smoothing spline technique to our stitching problem because we needed a general non-parametric method. We adapted one of the algorithms in the literature, by Hutchinson and deHoog, to our needs. The modified algorithm and the resulting code perform a cubic smoothing spline fit to multiple datamore » channels with redundant time samples and missing data points. The data channels can have different, time-varying, zero-mean white noise characteristics. The method we employ automatically determines an optimal smoothing level by minimizing the Generalized Cross Validation (GCV) score. In order to automatically validate the smoothing level selection, the Weighted Sum-Squared Residual (WSSR) and zero-mean tests are performed on the residuals. Further, confidence intervals, both analytical and Monte Carlo, are also calculated. In this paper, we describe the derivation of our cubic smoothing spline algorithm. We outline the algorithm and test it with simulated and experimental data.« less

The fcc - bcc structural transition: I. A band theoretical study for Li, K, Rb, Ca, Sr, and the transition metals Ti and V

NASA Astrophysics Data System (ADS)

Sliwko, V. L.; Mohn, P.; Schwarz, K.; Blaha, P.

1996-02-01

Employing a high-precision band structure method (FP LAPW - full potential linearized augmented plane wave) we calculate the total energy variation along the tetragonal distortion path connecting the body centred cubic (bcc) and the face centred cubic (fcc) structures. The total energy along this Bain transformation is calculated, varying c/a and volume, providing a first-principles energy surface which has two minima as a function of c/a. These are shallow and occur for the sp metals at the two cubic structures, while Ti (V) has a minimum at fcc (bcc) but a saddle point (i.e. a minimum in volume and a maximum with respect to c/a) at the other cubic structure. These features can be analysed in terms of an interplay between the Madelung contribution and the band energies. Our total energy results allow us to calculate the elastic constants 0953-8984/8/7/006/img1 and 0953-8984/8/7/006/img2 and to study the influence of pressure on the phase stability. These energy surfaces will be used in part II of this paper to investigate finite-temperature effects by mapping them to a Landau - Ginzburg expansion.

Risk analysis and guidelines for harvest activities in wisconsin oak timberlands to minimize oak wilt threat

Treesearch

Jennifer Juzwik; Jane Cummings-Carlson; Kyoko Scanlon

2010-01-01

Oaks (Quercus spp.) are an important species group in the forests of Wisconsin. The State’s timberland typed as oak-hickory forest was estimated at 2.9 million acres in 1996. Growing stock volume for red oak was estimated at 2.4 billion cubic feet, whereas select white oak volume was estimated to be 927 million cubic feet. Oak wilt, the oak disease...

In-situ X-ray diffraction study of phase transformations in the Am-O system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebreton, Florent, E-mail: florent.lebreton@cea.fr; GEMH, ENSCI, 87065 Limoges; Belin, Renaud C., E-mail: renaud.belin@cea.fr

2012-12-15

In the frame of minor actinides recycling, americium can be transmuted by adding it in UO{sub 2} or (U, Pu)O{sub 2} fuels. Americium oxides exhibiting a higher oxygen potential than U or Pu oxides, its addition alters the fuel properties. To comprehend its influence, a thorough knowledge of the Am-O phase equilibria diagram and of thermal expansion behavior is of main interest. Due to americium scarcity and high radiotoxicity, few experimental reports on this topic are available. Here we present in-situ high-temperature XRD results on the reduction from AmO{sub 2} to Am{sub 2}O{sub 3}. We show that fluorite (Fm-3m) AmO{submore » 2} is reduced to cubic (Ia-3) C Prime -type Am{sub 2}O{sub 3+{delta}}, and then into hexagonal (P6{sub 3}/mmc) A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. We also demonstrate the transitional existence of the monoclinic (C2/m) B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion behavior of the hexagonal Am{sub 2}O{sub 3} between room temperature and 1840 K. - Graphical abstract: Americium dioxide was in situ studied by high-temperature X-ray diffraction. First, fluorite AmO{sub 2} is reduced to cubic C Prime -type Am{sub 2}O{sub 3+{delta}} and then transforms into hexagonal A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. Then, we demonstrate the transitional existence of monoclinic B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion of A-type Am{sub 2}O{sub 3} between room temperature and 1840 K. This work may contribute to a better understanding of Am oxide behavior. Highlights: Black-Right-Pointing-Pointer We realize an in-situ high-temperature X-ray diffraction study on an AmO{sub 2} sample. Black-Right-Pointing-Pointer Fluorite AmO{sub 2} transforms to cubic Am{sub 2}O{sub 3+{delta}} and then to hexagonal Am{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Little-known monoclinic Am{sub 2}O{sub 3} is observed during the cubic-to-hexagonal transition. Black-Right-Pointing-Pointer Lattice parameter thermal expansion of hexagonal Am{sub 2}O{sub 3} is given up to 1840 K. Black-Right-Pointing-Pointer We give additional data on AmO{sub 2} lattice parameter expansion under self-irradiation.« less

Discovery of sodium in the atmosphere of mercury.

PubMed

Potter, A; Morgan, T

1985-08-16

The spectrum of Mercury at the Fraunhofer sodium D lines shows strong emission features that are attributed to resonant scattering of sunlight from sodium vapor in the atmosphere of the planet. The total column abundance of sodium was estimated to be 8.1 x 10(11) atoms per square centimeter, which corresponds to a surface density at the subsolar point of about 1.5 x 10(5) atoms per cubic centimeter. The most abundant atmospheric species found by the Mariner 10 mission to Mercury was helium, with a surface density of 4.5 x 10(3) atoms per cubic centimeter. It now appears that sodium vapor is a major constituent of Mercury's atmosphere.

Antiswarming: Structure and dynamics of repulsive chemically active particles

NASA Astrophysics Data System (ADS)

Yan, Wen; Brady, John F.

2017-12-01

Chemically active Brownian particles with surface catalytic reactions may repel each other due to diffusiophoretic interactions in the reaction and product concentration fields. The system behavior can be described by a "chemical" coupling parameter Γc that compares the strength of diffusiophoretic repulsion to Brownian motion, and by a mapping to the classical electrostatic one component plasma (OCP) system. When confined to a constant-volume domain, body-centered cubic (bcc) crystals spontaneously form from random initial configurations when the repulsion is strong enough to overcome Brownian motion. Face-centered cubic (fcc) crystals may also be stable. The "melting point" of the "liquid-to-crystal transition" occurs at Γc≈140 for both bcc and fcc lattices.

Variable-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type barium titanate phases.

PubMed

Nakatani, Tomotaka; Yoshiasa, Akira; Nakatsuka, Akihiko; Hiratoko, Tatsuya; Mashimo, Tsutomu; Okube, Maki; Sasaki, Satoshi

2016-02-01

A variable-temperature single-crystal X-ray diffraction study of a synthetic BaTiO3 perovskite has been performed over the temperature range 298-778 K. A transition from a tetragonal (P4mm) to a cubic (Pm3m) phase has been revealed near 413 K. In the non-centrosymmetric P4mm symmetry group, both Ti and O atoms are displaced along the c-axis in opposite directions with regard to the Ba position fixed at the origin, so that Ti(4+) and Ba(2+) cations occupy off-center positions in the TiO6 and BaO12 polyhedra, respectively. Smooth temperature-dependent changes of the atomic coordinates become discontinuous with the phase transition. Our observations imply that the cations remain off-center even in the high-temperature cubic phase. The temperature dependence of the mean-square displacements of Ti in the cubic phase includes a significant static component which means that Ti atoms are statistically distributed in the off-center positions.

Inverting x,y grid coordinates to obtain latitude and longitude in the vanderGrinten projection

NASA Technical Reports Server (NTRS)

Rubincam, D. P.

1980-01-01

The latitude and longitude of a point on the Earth's surface are found from its x,y grid coordinates in the vanderGrinten projection. The latitude is a solution of a cubic equation and the longitude a solution of a quadratic equation. Also, the x,y grid coordinates of a point on the Earth's surface can be found if its latitude and longitude are known by solving two simultaneous quadratic equations.

Numerical Procedures for Analysis of Structural Shells.

DTIC Science & Technology

1981-03-01

40 freedoms. The basic freedom pattern contains two freedoms at each of 16 shell surface nodes and one freedom at each of 8 midsurface nodes, again for...schene it is possible to make the midsurface strain vanish at all integration points if the inplane displacemnts are represented by cubic shape

40 CFR 440.140 - Applicability; description of the gold placer mine subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Gold... gold bearing ores from placer deposits; and (2) The beneficiation processes which use gravity... applicable to any mines or beneficiation processes which process less than 1500 cubic yards (cu yd) of ore...

Lattice thermal expansion for normal tetrahedral compound semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Omar, M.S.

2007-02-15

The cubic root of the deviation of the lattice thermal expansion from that of the expected value of diamond for group IV semiconductors, binary compounds of III-V and II-VI, as well as several ternary compounds from groups I-III-VI{sub 2}, II-IV-V{sub 2} and I-IV{sub 2}V{sub 3} semiconductors versus their bonding length are given straight lines. Their slopes were found to be 0.0256, 0.0210, 0.0170, 0.0259, 0.0196, and 0.02840 for the groups above, respectively. Depending on the valence electrons of the elements forming these groups, a formula was found to correlate all the values of the slopes mentioned above to that ofmore » group IV. This new formula which depends on the melting point and the bonding length as well as the number of valence electrons for the elements forming the compounds, will gives best calculated values for lattice thermal expansion for all compounds forming the groups mentioned above. An empirical relation is also found between the mean ionicity of the compounds forming the groups and their slopes mentioned above and that gave the mean ionicity for the compound CuGe{sub 2}P{sub 3} in the range of 0.442.« less

Cost-Effectiveness of Initiating Antiretroviral Therapy at Different Points in TB Treatment in HIV-TB Coinfected Ambulatory Patients in South Africa.

PubMed

Naidoo, Kogieleum; Grobler, Anneke C; Deghaye, Nicola; Reddy, Tarylee; Gengiah, Santhanalakshmi; Gray, Andrew; Abdool Karim, Salim

2015-08-15

Initiation of antiretroviral therapy (ART) during tuberculosis (TB) treatment improves survival in TB-HIV coinfected patients. In patients with CD4 counts <50 cells per cubic millimeter, there is a substantial clinical and survival benefit of early ART initiation. The purpose of this study was to assess the costs and cost-effectiveness of starting ART at various time points during TB treatment in patients with CD4 counts ≥50 cells per cubic millimeter. In the SAPiT trial, 642 HIV-TB coinfected patients were randomized to 3 arms: receiving ART within 4 weeks of starting TB treatment (early treatment arm; Arm-1), after the intensive phase of TB treatment (late treatment arm; Arm-2), or after completing TB treatment (sequential arm; Arm-3). Direct health care costs were measured from a provider perspective using a micro-costing approach. The incremental cost per death averted was calculated using the trial outcomes. For patients with CD4 count ≥50 cells per cubic millimeter, median monthly variable costs per patient were US $116, US $113, and US $102 in Arm-1, Arm-2 and Arm-3, respectively. There were 12 deaths in 177 patients in Arm-1, 8 deaths in 180 patients in the Arm-2, and 19 deaths in 172 patients in Arm-3. Although the costs were lower in Arm-3, it had a substantially higher mortality rate. The incremental cost per death averted associated with moving from Arm-3 to Arm-2 was US $4199. There was no difference in mortality between Arm-1 and Arm-2, but Arm-1 was slightly more expensive. Initiation of ART after the completion of the intensive phase of TB treatment is cost-effective for patients with CD4 counts ≥50 cells per cubic millimeter.

Monitoring channel morphology and bluff erosion at two installations of flow-deflecting vanes, North Fish Creek, Wisconsin, 2000-03

USGS Publications Warehouse

Fitzpatrick, Faith A.; Peppler, Marie C.; Schwar, Heather E.; Hoopes, John A.; Diebel, Matthew W.

2005-01-01

Flow-deflecting vanes were installed in the streambed along two meander bends with eroding bluffs in 2000 and 2001 in the upper main stem of North Fish Creek, a tributary to Lake Superior in Wisconsin. About 45 vanes were arranged in 15 arrays at each site to deflect the flow away from the eroding toe or base of the bluff (outside of a bend) and toward the point bar (inside of a bend). Channel cross-section and bluff-erosion surveys were done and streamflow and stage were measured before, during, and after vane installation to monitor changes in channel morphology and bluff erosion in the context of hydrologic conditions. There were two large floods in the study area in spring 2001 (recurrence interval of approximately 100 years) and in spring 2002 (recurrence intervals of approximately 50 years). Some maintenance and replacement of vanes were needed after the floods. Most of the channel-morphology changes resulted from the large floods, and fewer changes resulted from near-bankfull or at-bankfull flows (one in October 2002 and four in April and May 2003). At the bluff located 16.4 river miles upstream of the creek mouth (site 16.4), the vanes deflected flow and caused the channel to migrate away from the base of the bluff and toward the point bar, allowing sediment to deposit along the bluff base. The 361-foot reach at site 16.4 had a net gain of 6,740 cubic feet of sediment over the entire monitoring period (2000?03). Deposition (10,660 cubic feet) occurred mainly along the base of the bluff in the downstream part of the bend. Erosion occurred at site 16.4 along the streambed, the point bar side of the channel, and along a midchannel bar (1,220, 1,610, and 1,090 cubic feet, respectively). Less channel migration was observed during 2001-03 at another bluff located 12.2 river miles upstream of the creek mouth (site 12.2), which had a net loss of sediment through the 439-foot reach of 2,800 cubic feet over the monitored time period. The main volume of sediment was lost from the bluff toe in the downstream part of the bend (7,100 cubic feet). Monitored channel-morphology changes at site 12.2 were less than at site 16.4, most likely because installation was done after the April 2001 flood, which caused major changes in channel morphology at site 16.4, and because the monitoring period was shorter than at site 16.4. Bluff-erosion data from both sites indicate that mass wasting and block failures from the bluff top occur episodically and will continue to occur for decades or more.

Structure family and polymorphous phase transition in the compounds with soft sublattice: Cu{sub 2}Se as an example

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Wujie; State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050; Lu, Ping

Quite a few interesting but controversial phenomena, such as simple chemical composition but complex structures, well-defined high-temperature cubic structure but intriguing phase transition, coexist in Cu{sub 2}Se, originating from the relatively rigid Se framework and “soft” Cu sublattice. However, the electrical transport properties are almost uninfluenced by such complex substructures, which make Cu{sub 2}Se a promising high-performance thermoelectric compound with extremely low thermal conductivity and good power factor. Our work reveals that the crystal structure of Cu{sub 2}Se at the temperature below the phase-transition point (∼400 K) should have a group of candidate structures that all contain a Se-dominated face-centered-cubic-likemore » layered framework but nearly random site occupancy of atoms from the “soft” Cu sublattice. The energy differences among those structures are very low, implying the coexistence of various structures and thus an intrinsic structure complexity with a Se-based framework. Detailed analyses indicate that observed structures should be a random stacking of those representative structure units. The transition energy barriers between each two of those structures are estimated to be zero, leading to a polymorphous phase transition of Cu{sub 2}Se at increasing temperature. Those are all consistent with experimental observations.« less

Lattice softening in body-centered-cubic lithium-magnesium alloys

NASA Astrophysics Data System (ADS)

Winter, I. S.; Tsuru, T.; Chrzan, D. C.

2017-08-01

A first-principles investigation of the influence of lattice softening on lithium-magnesium alloys near the body-centered-cubic (bcc)/hexagonal close-packed (hcp) transition composition is presented. Results show that lithium-magnesium alloys display a softening of the shear modulus C11-C12 , and an acoustic phonon branch between the Γ and N high symmetry points, as the composition approaches the stability limit for the bcc phase. This softening is accompanied by an increase in the size of the dislocation core region. Ideal tensile strength calculations predict that ordered phases of lithium-magnesium alloys are intrinsically brittle. Methods to make the alloys more ductile are discussed, and the propensity for these alloys to display gum-metal-like behavior is assessed.

Dislocation nucleation from symmetric tilt grain boundaries in body-centered cubic vanadium

NASA Astrophysics Data System (ADS)

Xu, Shuozhi; Su, Yanqing

2018-05-01

We perform molecular dynamics (MD) simulations with two interatomic potentials to study dislocation nucleation from six symmetric tilt grain boundaries (GB) using bicrystal models in body-centered cubic vanadium. The influences of the misorientation angle are explored in the context of activated slip systems, critical resolved shear stress (CRSS), and GB energy. It is found that for four GBs, the activated slip systems are not those with the highest Schmid factor, i.e., the Schmid law breaks down. For all misorientation angles, the bicrystal is associated with a lower CRSS than their single crystalline counterparts. Moreover, the GB energy decreases in compressive loading at the yield point with respect to the undeformed configuration, in contrast to tensile loading.

Construction of a cardiac conduction system subject to extracellular stimulation.

PubMed

Clements, Clyde; Vigmond, Edward

2005-01-01

Proper electrical excitation of the heart is dependent on the specialized conduction system that coordinates the electrical activity from the atria to the ventricles. This paper describes the construction of a conduction system as a branching network of Purkinje fibers on the endocardial surface. Endocardial surfaces were extracted from an FEM model of the ventricles and transformed to 2D. A Purkinje network was drawn on top and the inverse transform performed. The underlying mathematics utilized one dimensional cubic Hermite finite elements. Compared to linear elements, the cubic Hermite solution was found to have a much smaller RMS error. Furthermore, this method has the advantage of enforcing current conservation at bifurcation and unification points, and allows for discrete coupling resistances.

Atomistic aspects of ductile responses of cubic silicon carbide during nanometric cutting

PubMed Central

2011-01-01

Cubic silicon carbide (SiC) is an extremely hard and brittle material having unique blend of material properties which makes it suitable candidate for microelectromechanical systems and nanoelectromechanical systems applications. Although, SiC can be machined in ductile regime at nanoscale through single-point diamond turning process, the root cause of the ductile response of SiC has not been understood yet which impedes significant exploitation of this ceramic material. In this paper, molecular dynamics simulation has been carried out to investigate the atomistic aspects of ductile response of SiC during nanometric cutting process. Simulation results show that cubic SiC undergoes sp3-sp2 order-disorder transition resulting in the formation of SiC-graphene-like substance with a growth rate dependent on the cutting conditions. The disorder transition of SiC causes the ductile response during its nanometric cutting operations. It was further found out that the continuous abrasive action between the diamond tool and SiC causes simultaneous sp3-sp2 order-disorder transition of diamond tool which results in graphitization of diamond and consequent tool wear. PMID:22078069

Magnetic Resonance Characterization of Defects in Icosahedral and Cubic Boron Arsenide Bulk Crystals

NASA Astrophysics Data System (ADS)

Glaser, E. R.; Freitas, J. A., Jr.; Cress, C. D.; Perkins, F. K.; Prokes, S. M.; Ruppalt, L. B.; Culbertson, J. C.; Whiteley, C.; Edgar, J. H.; Tian, F.; Ren, Z.; Kim, J.; Shi, L.; Naval Research Lab Team; Kansas State U. Team; U. Houston Team; U. Texas Team

Low-temperature electron spin resonance (ESR) at 9.5 GHz and optically-detected magnetic resonance (ODMR) at 24 GHz were employed to investigate point defects in icosahedral and cubic Boron Arsenide bulk crystals. These semiconductors are of interest for use in high radiation and/or high temperature environments. ESR of the (001) B12As2 (Eg = 3.47 eV) mm-size platelets revealed two distinct features of unknown origin. The first signal is characterized by Zeeman splitting g-values of g|| = 2.017, g⊥ = 2.0183 while the second with g|| = 2.0182, g⊥ = 1.9997. Most notably, the second signal was also observed from ODMR on the broad 2.4 eV ``yellow/green'' photoluminescence band previously reported for these crystals and suggests its direct involvement in this likely defect-related radiative recombination process. Preliminary ESR obtained for the 100-300 micron-size cubic BAs crystals revealed a signal with g-value of 2.018 (very similar to that found for the B12As2 crystals) and broad FWHM value of 182 G. Possible origins of these defects will be discussed.

Atomistic aspects of ductile responses of cubic silicon carbide during nanometric cutting.

PubMed

Goel, Saurav; Luo, Xichun; Reuben, Robert L; Rashid, Waleed Bin

2011-11-11

Cubic silicon carbide (SiC) is an extremely hard and brittle material having unique blend of material properties which makes it suitable candidate for microelectromechanical systems and nanoelectromechanical systems applications. Although, SiC can be machined in ductile regime at nanoscale through single-point diamond turning process, the root cause of the ductile response of SiC has not been understood yet which impedes significant exploitation of this ceramic material. In this paper, molecular dynamics simulation has been carried out to investigate the atomistic aspects of ductile response of SiC during nanometric cutting process. Simulation results show that cubic SiC undergoes sp3-sp2 order-disorder transition resulting in the formation of SiC-graphene-like substance with a growth rate dependent on the cutting conditions. The disorder transition of SiC causes the ductile response during its nanometric cutting operations. It was further found out that the continuous abrasive action between the diamond tool and SiC causes simultaneous sp3-sp2 order-disorder transition of diamond tool which results in graphitization of diamond and consequent tool wear.

Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics

NASA Astrophysics Data System (ADS)

Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

2016-12-01

Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO2 sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016), 10.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

Relationship between sample volumes and modulus of human vertebral trabecular bone in micro-finite element analysis.

PubMed

Wen, Xin-Xin; Xu, Chao; Zong, Chun-Lin; Feng, Ya-Fei; Ma, Xiang-Yu; Wang, Fa-Qi; Yan, Ya-Bo; Lei, Wei

2016-07-01

Micro-finite element (μFE) models have been widely used to assess the biomechanical properties of trabecular bone. How to choose a proper sample volume of trabecular bone, which could predict the real bone biomechanical properties and reduce the calculation time, was an interesting problem. Therefore, the purpose of this study was to investigate the relationship between different sample volumes and apparent elastic modulus (E) calculated from μFE model. 5 Human lumbar vertebral bodies (L1-L5) were scanned by micro-CT. Cubic concentric samples of different lengths were constructed as the experimental groups and the largest possible volumes of interest (VOI) were constructed as the control group. A direct voxel-to-element approach was used to generate μFE models and steel layers were added to the superior and inferior surface to mimic axial compression tests. A 1% axial strain was prescribed to the top surface of the model to obtain the E values. ANOVA tests were performed to compare the E values from the different VOIs against that of the control group. Nonlinear function curve fitting was performed to study the relationship between volumes and E values. The larger cubic VOI included more nodes and elements, and more CPU times were needed for calculations. E values showed a descending tendency as the length of cubic VOI decreased. When the volume of VOI was smaller than (7.34mm(3)), E values were significantly different from the control group. The fit function showed that E values approached an asymptotic values with increasing length of VOI. Our study demonstrated that apparent elastic modulus calculated from μFE models were affected by the sample volumes. There was a descending tendency of E values as the length of cubic VOI decreased. Sample volume which was not smaller than (7.34mm(3)) was efficient enough and timesaving for the calculation of E. Copyright © 2016 Elsevier Ltd. All rights reserved.

A fresh look at dense hydrogen under pressure. IV. Two structural models on the road from paired to monatomic hydrogen, via a possible non-crystalline phase

NASA Astrophysics Data System (ADS)

Labet, Vanessa; Hoffmann, Roald; Ashcroft, N. W.

2012-02-01

In this paper, we examine the transition from a molecular to monatomic solid in hydrogen over a wide pressure range. This is achieved by setting up two models in which a single parameter δ allows the evolution from a molecular structure to a monatomic one of high coordination. Both models are based on a cubic Bravais lattice with eight atoms in the unit cell; one belongs to space group Pabar 3, the other to space group Rbar 3m. In Pabar 3 one moves from effective 1-coordination, a molecule, to a simple cubic 6-coordinated structure but through a very special point (the golden mean is involved) of 7-coordination. In Rbar 3m, the evolution is from 1 to 4 and then to 3 to 6-coordinate. If one studies the enthalpy as a function of pressure as these two structures evolve (δ increases), one sees the expected stabilization of minima with increased coordination (moving from 1 to 6 to 7 in the Pabar 3 structure, for instance). Interestingly, at some specific pressures, there are in both structures relatively large regions of phase space where the enthalpy remains roughly the same. Although the structures studied are always higher in enthalpy than the computationally best structures for solid hydrogen - those emerging from the Pickard and Needs or McMahon and Ceperley numerical laboratories - this result is suggestive of the possibility of a microscopically non-crystalline or "soft" phase of hydrogen at elevated pressures, one in which there is a substantial range of roughly equi-enthalpic geometries available to the system. A scaling argument for potential dynamic stabilization of such a phase is presented.

Defining window-boundaries for genomic analyses using smoothing spline techniques

DOE PAGES

Beissinger, Timothy M.; Rosa, Guilherme J.M.; Kaeppler, Shawn M.; ...

2015-04-17

High-density genomic data is often analyzed by combining information over windows of adjacent markers. Interpretation of data grouped in windows versus at individual locations may increase statistical power, simplify computation, reduce sampling noise, and reduce the total number of tests performed. However, use of adjacent marker information can result in over- or under-smoothing, undesirable window boundary specifications, or highly correlated test statistics. We introduce a method for defining windows based on statistically guided breakpoints in the data, as a foundation for the analysis of multiple adjacent data points. This method involves first fitting a cubic smoothing spline to the datamore » and then identifying the inflection points of the fitted spline, which serve as the boundaries of adjacent windows. This technique does not require prior knowledge of linkage disequilibrium, and therefore can be applied to data collected from individual or pooled sequencing experiments. Moreover, in contrast to existing methods, an arbitrary choice of window size is not necessary, since these are determined empirically and allowed to vary along the genome.« less

Critical phenomena at the complex tensor ordering phase transition

NASA Astrophysics Data System (ADS)

Boettcher, Igor; Herbut, Igor F.

2018-02-01

We investigate the critical properties of the phase transition towards complex tensor order that has been proposed to occur in spin-orbit-coupled superconductors. For this purpose, we formulate the bosonic field theory for fluctuations of the complex irreducible second-rank tensor order parameter close to the transition. We then determine the scale dependence of the couplings of the theory by means of the perturbative renormalization group (RG). For the isotropic system, we generically detect a fluctuation-induced first-order phase transition. The initial values for the running couplings are determined by the underlying microscopic model for the tensorial order. As an example, we study three-dimensional Luttinger semimetals with electrons at a quadratic band-touching point. Whereas the strong-coupling transition of the model receives substantial fluctuation corrections, the weak-coupling transition at low temperatures is rendered only weakly first order due to the presence of a fixed point in the vicinity of the RG trajectory. If the number of fluctuating complex components of the order parameter is reduced by cubic anisotropy, the theory maps onto the field theory for frustrated magnetism.

Fermion-induced quantum critical points in two-dimensional Dirac semimetals

NASA Astrophysics Data System (ADS)

Jian, Shao-Kai; Yao, Hong

2017-11-01

In this paper we investigate the nature of quantum phase transitions between two-dimensional Dirac semimetals and Z3-ordered phases (e.g., Kekule valence-bond solid), where cubic terms of the order parameter are allowed in the quantum Landau-Ginzberg theory and the transitions are putatively first order. From large-N renormalization-group (RG) analysis, we find that fermion-induced quantum critical points (FIQCPs) [Z.-X. Li et al., Nat. Commun. 8, 314 (2017), 10.1038/s41467-017-00167-6] occur when N (the number of flavors of four-component Dirac fermions) is larger than a critical value Nc. Remarkably, from the knowledge of space-time supersymmetry, we obtain an exact lower bound for Nc, i.e., Nc>1 /2 . (Here the "1/2" flavor of four-component Dirac fermions is equivalent to one flavor of four-component Majorana fermions). Moreover, we show that the emergence of two length scales is a typical phenomenon of FIQCPs and obtain two different critical exponents, i.e., ν ≠ν' , by large-N RG calculations. We further give a brief discussion of possible experimental realizations of FIQCPs.

Scanning electron microscopy, X-ray diffraction and thermal analysis study of the TiH{sub 2} foaming agent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandrino, Djordje, E-mail: djordje.mandrino@imt.si; Paulin, Irena; Skapin, Sreco D.

2012-10-15

The decomposition of commercially available TiH{sub 2} was investigated while performing different thermal treatments. TiH{sub 2} powder, which is widely used as a foaming agent, was heat treated at 450 Degree-Sign C for various times, from 15 min to 120 min. Scanning electron microscopy (SEM) images of the surfaces at different magnifications were obtained and interpreted. A Bragg-Brentano X-ray diffractometer was used to measure the X-ray diffraction (XRD) spectra on all five samples. A close examination of the diffraction spectra showed that for an as-received sample and samples undergoing the longest thermal treatment (1 and 2 h) these spectra canmore » be explained as deriving from cubic TiH{sub 1.924}, while for the other two samples they can be explained as deriving from tetragonal TiH{sub 1.924}. A constant-unit-cell-volume phase transition between the cubic and tetragonal phases in TiH{sub 2-y}-type compounds had been described in the literature. The unit-cell parameters obtained from measured spectra confirm that within the measurement uncertainty the unit-cell volume is indeed constant in all five samples. Thermo-gravimetry (TG) and differential thermal analysis (DTA) measurements were performed on all the samples, showing that the intensity of the dehydrogenation depends on the previous treatment of the TiH{sub 2}. After the thermal analysis XRD of the samples was performed again and the material was found to exhibit a Ti-like unit cell, but slightly enlarged due to the unreleased hydrogen. - Highlights: Black-Right-Pointing-Pointer TiH{sub 2} samples were cubic or tetragonal TiH{sub 1.924} Black-Right-Pointing-Pointer Onset of the hydrogen release temperature increases with the pre-treatment time. Black-Right-Pointing-Pointer Thermal dehydrogenation for the as-prepared TiH{sub 2} is a three-step process. Black-Right-Pointing-Pointer After thermal analysis 2 residual hydrogen TiH{sub x} phases, close to {alpha}Ti, appeared.« less

Spacing and slash pine quality timber prodution

Treesearch

Frank A. Bennett

1969-01-01

Cubic volume production as related to spacing in planted slash pine (Pinus etliottii var. elliottii) is well understood. Yield increases as number of surviving trees per acre increases, although at a diminishing rate after a certain point. It is also well known that wider spacings, 200 to 400 trees per acre, are necessary for...

The Viability of a Metamaterial Solution for the Defense of an Incident High-Energy Electromagnetic Beam

DTIC Science & Technology

2010-12-01

INTRODUCTION ............................................1 A. DIRECTED ENERGY WEAPONS ( DEW ) ......................1 B. FREE ELECTRON LASER (FEL...WEAPONS (C- DEW ) ............7 1. Navy Relevance ................................7 2. Problem Description ...........................7 II...invisibility cloaks from [9].................................18 Figure 7. Simple cubic lattice of points in co-coordinate system (left) maps into a

Raman spectroscopic studies of defect structures and phase transition in hyper-stoichiometric UO(2+x).

PubMed

He, Heming; Shoesmith, David

2010-07-28

A method to determine the defect structures in hyper-stoichiometric UO(2+x) using a combination of XRD and Raman spectroscopy has been developed. A sequence of phase transitions, from cubic to tetragonal symmetry, occurs with increasing degree of non-stoichiometry. This sequence proceeds from a cubic phase through an intermediate t''-type tetragonal (axial ratio c/a = 1) phase to a final t-type tetragonal (c/a not = 1) phase. Four distinct structural defect regions can be identified in the stoichiometry range, UO(2) to U(3)O(7): (i) a random point defect structure (x (in UO(2+x)) < or = 0.05); (ii) a non-stoichiometry region (0.05 < or = x < or = 0.15) over which point defects are gradually eliminated and replaced by the Willis 2:2:2 cluster; (iii) a mixture of Willis and cuboctahedral clusters (0.15 < or = x < or = 0.23); (iv) the cuboctahedral cluster (x > or = 0.23). The geometry and steric arrangement of these defects is primarily determined by the concentration of the excess-oxygen interstitials.

Optimization of chemometric approaches for the extraction of isorhamnetin-3-O-rutinoside from Calendula officinalis L.

PubMed

Moraes, Maria Lourdes Leite; da Silva, Heron Dominguez Torres; Blanes, Lucas; Doble, Philip; Tavares, Marina Franco Maggi

2016-06-05

The application of Design of Experiments (DoE) to the determination of optimum conditions for an extraction process relies on the correct selection of mathematical models. The linear model is the one typically used; however, in some cases it does not always have superior performance, ignoring the real nature of the data and its appropriate descriptive model. In order to evaluate the extraction efficiency of isorhamnetin-3-O-rutinoside from flowers of Calendula officinalis L. a multivariate factorial analysis was used. Simulations were conducted using linear, quadratic, full cubic and special cubic models. A Simplex-Centroid design was chosen as it delivered greater precision with only minor errors versus other models tested. Analyses were performed by capillary zone electrophoresis using sodium tetraborate buffer (40mmolL(-1), pH 9.4) containing 10% methanol. The detection was linear over a range of 8.0-50.0mgL(-1) (r(2)=0.996), and the limits of detection (LOD) and quantification (LOQ) for isorhamnetin-3-O-rutinoside were 3.44mgL(-1) and 11.47mgL(-1), respectively. The full cubic model showed the best extraction results, with an error of 3.40% compared to analysis of variance, and a determination coefficient of 0.974. The difference between the responses at the reference point, calculated by the model, and the experimental response, varies around 2.72% for full cubic model. Comparison of the four models showed the full cubic model was the most appropriate one, allowing greater efficiency in the extraction of isorhamnetin-3-O-rutinoside. Selection of the model made it possible to obtain a 60% increase in sensitivity compared to the linear model. Copyright © 2016. Published by Elsevier B.V.

Flood of July 9-11, 1993, in the Raccoon River basin, west-central Iowa

USGS Publications Warehouse

Eash, D.A.; Koppensteiner, B.A.

1997-01-01

Water-surface-elevation profiles and peak discharges for the flood of July 9-11, 1993, in the Raccoon River Basin, west-central Iowa, are presented in this report. The profiles illustrate the 1993 flood along the Raccoon, North Raccoon, South Raccoon, and Middle Raccoon Rivers and along Brushy and Storm Creeks in the west-central Iowa counties of Carroll, Dallas, Greene, Guthrie, and Polk. Water-surface-elevation profiles for the floods of June 1947, March 1979, and June 29- July 1, 1986, in the Raccoon River Basin also are included in the report for comparative purposes. The July 9-11, 1993, flood is the largest known peak discharge at gaging stations Brushy Creek near Templeton (station number 05483318) 19,000 cubic feet per second, Middle Raccoon River near Bayard (station number 05483450) 27,500 cubic feet per second, Middle Raccoon River at Panora (station number 05483600) 22,400 cubic feet per second, South Raccoon River at Redfield (station number 05484000) 44,000 cubic feet per second, and Raccoon River at Van Meter (station number 05484500) 70,100 cubic feet per second. The peak discharges were, respectively, 1.5, 1.3, 1.1,1.2, and 1.3 times larger than calculated 100-year recurrence-interval discharges. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Raccoon River Basin using flood information collected through 1996. A flood history summarizes rainfall conditions and damages for floods that occurred during 1947, 1958, 1979, 1986, 1990, and 1993. Information on temporary bench marks and reference points established in the Raccoon River Basin during 1976-79 and 1995-97 also is included in the report.

Fluid synthesis and structure of a new polymorphic modification of boron nitride

NASA Astrophysics Data System (ADS)

Pokropivny, V. V.; Smolyar, A. S.; Ovsiannikova, L. I.; Pokropivny, A. V.; Kuts, V. A.; Lyashenko, V. I.; Nesterenko, Yu. V.

2013-04-01

A new previously unknown phase of boron nitride with a hardness of 0.41-0.63 GPa has been pre-pared by the supercritical fluid synthesis. The presence of a new phase is confirmed by the X-ray spectra and IR absorption spectra, where new reflections and bands are distinguished. The fundamental reflection of the X-ray diffraction pattern is d = 0.286-0.291 nm, and the characteristic band in the infrared absorption spectrum is observed at 704 cm-1. The X-ray diffraction pattern and the experimental and theoretical infrared absorption spectra show that a new synthesized boron nitride phase can be a cluster crystal (space group 211) with a simple cubic lattice. Cage clusters of a fullerene-like morphology B24N24 with point symmetry O are arranged in lattice sites.

Instability of the layered orthorhombic post-perovskite phase of SrTiO3 and other candidate orthorhombic phases under pressure

NASA Astrophysics Data System (ADS)

Bhandari, Churna; Lambrecht, Walter R. L.

2018-06-01

While the tetragonal antiferro-electrically distorted (AFD) phase with space group I 4 / mcm is well known for SrTiO3 to occur below 105 K, there are also some hints in the literature of an orthorhombic phase, either at the lower temperature or at high pressure. A previously proposed orthorhombic layered structure of SrTiO3, known as the post-perovskite or CaIrO3 structure with space group Cmcm is shown to have significantly higher energy than the cubic or tetragonal phase and to have its minimum volume at larger volume than cubic perovskite. The Cmcm structure is thus ruled out. We also study an alternative Pnma phase obtained by two octahedral rotations about different axes. This phase is found to have slightly lower energy than the I 4 / mcm phase in spite of the fact that its parent, in-phase tilted P 4 / mbm phase is not found to occur. Our calculated enthalpies of formation show that the I 4 / mcm phase occurs at slightly higher volume than the cubic phase and has a negative transition pressure relative to the cubic phase, which suggests that it does not correspond to the high-pressure tetragonal phase. The enthalpy of the Pnma phase is almost indistinguishable from the I 4 / mcm phase. Alternative ferro-electric tetragonal and orthorhombic structures previously suggested in literature are discussed.

40 CFR Table 3 to Subpart Ppp of... - Group 1 Storage Vessels at Existing and New Affected Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Group 1 Storage Vessels at Existing...—Group 1 Storage Vessels at Existing and New Affected Sources Vessel capacity(cubic meters) Vapor Pressure a (kilopascals) 75 ≤capacity pressure of total...

40 CFR Table 3 to Subpart Ppp of... - Group 1 Storage Vessels at Existing and New Affected Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Group 1 Storage Vessels at Existing...—Group 1 Storage Vessels at Existing and New Affected Sources Vessel capacity(cubic meters) Vapor Pressure a (kilopascals) 75 ≤ capacity pressure of...

Sequence-selective encapsulation and protection of long peptides by a self-assembled FeII8L6 cubic cage

NASA Astrophysics Data System (ADS)

Mosquera, Jesús; Szyszko, Bartosz; Ho, Sarah K. Y.; Nitschke, Jonathan R.

2017-03-01

Self-assembly offers a general strategy for the preparation of large, hollow high-symmetry structures. Although biological capsules, such as virus capsids, are capable of selectively recognizing complex cargoes, synthetic encapsulants have lacked the capability to specifically bind large and complex biomolecules. Here we describe a cubic host obtained from the self-assembly of FeII and a zinc-porphyrin-containing ligand. This cubic cage is flexible and compatible with aqueous media. Its selectivity of encapsulation is driven by the coordination of guest functional groups to the zinc porphyrins. This new host thus specifically encapsulates guests incorporating imidazole and thiazole moieties, including drugs and peptides. Once encapsulated, the reactivity of a peptide is dramatically altered: encapsulated peptides are protected from trypsin hydrolysis, whereas physicochemically similar peptides that do not bind are cleaved.

The structural and Raman spectral studies on Ni0.5Cu0.5Fe2O4 ferrite

NASA Astrophysics Data System (ADS)

Somani, M.; Saleem, M.

2018-05-01

Spinel ferrite Ni0.5Cu0.5Fe2O4 has been successfully prepared via solid state reaction. The crystal structure studies using XRD technique revealed cubic structure of the sample. The XRD spectra was further refined via Retvield Refinement and all the parameters regarding structure were obtained which confirmed cubic structure. The assigned space group was found to be Fd-3m. Particle size was calculated to be 56 nm. The Raman Spectra revealed five active Raman modes which confirmed spinel structure.

On the existence of global solutions of the one-dimensional cubic NLS for initial data in the modulation space Mp,q (R)

NASA Astrophysics Data System (ADS)

Chaichenets, Leonid; Hundertmark, Dirk; Kunstmann, Peer; Pattakos, Nikolaos

2017-10-01

We prove global existence for the one-dimensional cubic nonlinear Schrödinger equation in modulation spaces Mp,p‧ for p sufficiently close to 2. In contrast to known results, [9] and [14], our result requires no smallness condition on initial data. The proof adapts a splitting method inspired by work of Vargas-Vega, Hyakuna-Tsutsumi and Grünrock to the modulation space setting and exploits polynomial growth of the free Schrödinger group on modulation spaces.

TakeTwo: an indexing algorithm suited to still images with known crystal parameters

PubMed Central

Ginn, Helen Mary; Roedig, Philip; Kuo, Anling; Evans, Gwyndaf; Sauter, Nicholas K.; Ernst, Oliver; Meents, Alke; Mueller-Werkmeister, Henrike; Miller, R. J. Dwayne; Stuart, David Ian

2016-01-01

The indexing methods currently used for serial femtosecond crystallography were originally developed for experiments in which crystals are rotated in the X-ray beam, providing significant three-dimensional information. On the other hand, shots from both X-ray free-electron lasers and serial synchrotron crystallo­graphy experiments are still images, in which the few three-dimensional data available arise only from the curvature of the Ewald sphere. Traditional synchrotron crystallography methods are thus less well suited to still image data processing. Here, a new indexing method is presented with the aim of maximizing information use from a still image given the known unit-cell dimensions and space group. Efficacy for cubic, hexagonal and orthorhombic space groups is shown, and for those showing some evidence of diffraction the indexing rate ranged from 90% (hexagonal space group) to 151% (cubic space group). Here, the indexing rate refers to the number of lattices indexed per image. PMID:27487826

TakeTwo: an indexing algorithm suited to still images with known crystal parameters

DOE PAGES

Ginn, Helen Mary; Roedig, Philip; Kuo, Anling; ...

2016-08-01

The indexing methods currently used for serial femtosecond crystallography were originally developed for experiments in which crystals are rotated in the X-ray beam, providing significant three-dimensional information. On the other hand, shots from both X-ray free-electron lasers and serial synchrotron crystallography experiments are still images, in which the few three-dimensional data available arise only from the curvature of the Ewald sphere. Traditional synchrotron crystallography methods are thus less well suited to still image data processing. Here, a new indexing method is presented with the aim of maximizing information use from a still image given the known unit-cell dimensions and spacemore » group. Efficacy for cubic, hexagonal and orthorhombic space groups is shown, and for those showing some evidence of diffraction the indexing rate ranged from 90% (hexagonal space group) to 151% (cubic space group). Here, the indexing rate refers to the number of lattices indexed per image.« less

Integrated Multi-Color Light Emitting Device Made with Hybrid Crystal Structure

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor)

2017-01-01

An integrated hybrid crystal Light Emitting Diode ("LED") display device that may emit red, green, and blue colors on a single wafer. The various embodiments may provide double-sided hetero crystal growth with hexagonal wurtzite III-Nitride compound semiconductor on one side of (0001) c-plane sapphire media and cubic zinc-blended III-V or II-VI compound semiconductor on the opposite side of c-plane sapphire media. The c-plane sapphire media may be a bulk single crystalline c-plane sapphire wafer, a thin free standing c-plane sapphire layer, or crack-and-bonded c-plane sapphire layer on any substrate. The bandgap energies and lattice constants of the compound semiconductor alloys may be changed by mixing different amounts of ingredients of the same group into the compound semiconductor. The bandgap energy and lattice constant may be engineered by changing the alloy composition within the cubic group IV, group III-V, and group II-VI semiconductors and within the hexagonal III-Nitrides.

Integrated Multi-Color Light Emitting Device Made with Hybrid Crystal Structure

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor)

2016-01-01

An integrated hybrid crystal Light Emitting Diode ("LED") display device that may emit red, green, and blue colors on a single wafer. The various embodiments may provide double-sided hetero crystal growth with hexagonal wurtzite III-Nitride compound semiconductor on one side of (0001) c-plane sapphire media and cubic zinc-blended III-V or II-VI compound semiconductor on the opposite side of c-plane sapphire media. The c-plane sapphire media may be a bulk single crystalline c-plane sapphire wafer, a thin free standing c-plane sapphire layer, or crack-and-bonded c-plane sapphire layer on any substrate. The bandgap energies and lattice constants of the compound semiconductor alloys may be changed by mixing different amounts of ingredients of the same group into the compound semiconductor. The bandgap energy and lattice constant may be engineered by changing the alloy composition within the cubic group IV, group III-V, and group II-VI semiconductors and within the hexagonal III-Nitrides.

Bounce universe and black holes from critical Einsteinian cubic gravity

NASA Astrophysics Data System (ADS)

Feng, Xing-Hui; Huang, Hyat; Mai, Zhan-Feng; Lü, Hong

2017-11-01

We show that there exists a critical point for the coupling constants in Einsteinian cubic gravity in which the linearized equations on the maximally symmetric vacuum vanish identically. We construct an exact isotropic bounce universe in the critical theory in four dimensions. The comoving time runs from minus infinity to plus infinity, yielding a smooth universe bouncing between two de Sitter vacua. In five dimensions, we adopt a numerical approach to construct a bounce solution, in which a singularity occurs before the bounce takes place. We then construct exact anisotropic bounces that connect two isotropic de Sitter spacetimes with flat spatial sections. We further construct exact anti-de Sitter black holes in the critical theory in four and five dimensions and obtain an exact anti-de Sitter worm brane in four dimensions.

Lattice dynamics and the nature of structural transitions in organolead halide perovskites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comin, Riccardo; Crawford, Michael K.; Said, Ayman H.

Organolead halide perovskites are a family of hybrid organic-inorganic compounds whose remarkable optoelectronic properties have been under intensive scrutiny in recent years. Here we use inelastic x-ray scattering to study low-energy lattice excitations in single crystals of methylammonium lead iodide and bromide perovskites. Our findings confirm the displacive nature of the cubic-to-tetragonal phase transition, which is further shown, using neutron and x-ray diffraction, to be close to a tricritical point. Lastly, we detect quasistatic symmetry-breaking nanodomains persisting well into the high-temperature cubic phase, possibly stabilized by local defects. These findings reveal key structural properties of these materials, and also bearmore » important implications for carrier dynamics across an extended temperature range relevant for photovoltaic applications.« less

In-house SIRAS phasing of the polyunsaturated fatty-acid isomerase from Propionibacterium acnes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liavonchanka, Alena; Hornung, Ellen; Feussner, Ivo

2006-02-01

Low iodide concentrations were sufficient to allow SAD and SIRAS phasing of cubic crystals of a novel fatty acid isomerase using Cu Kα radiation. The polyenoic fatty-acid isomerase from Propionibacterium acnes (PAI) catalyzes the double-bond isomerization of linoleic acid to conjugated linoleic acid, which is a dairy- or meat-derived fatty acid in the human diet. PAI was overproduced in Escherichia coli and purified to homogeneity as a yellow-coloured protein. The nature of the bound cofactor was analyzed by absorption and fluorescence spectroscopy. Single crystals of PAI were obtained in two crystal forms. Cubic shaped crystals belong to space group I2{submore » 1}3, with a unit-cell parameter of 160.4 Å, and plate-like crystals belong to the monoclinic space group C2, with unit-cell parameters a = 133.7, b = 60.8, c = 72.2 Å, β = 115.8°. Both crystal forms contain one molecule per asymmetric unit and diffract to a resolution of better than 2.0 Å. Initial phases were obtained by SIRAS from in-house data from a cubic crystal that was soaked with an unusually low KI concentration of 0.25 M.« less

Effects of physiological environments on the hydration behavior of mineral trioxide aggregate.

PubMed

Lee, Yuan-Ling; Lee, Bor-Shiunn; Lin, Feng-Huei; Yun Lin, Ava; Lan, Wan-Hong; Lin, Chun-Pin

2004-02-01

Utilizing scanning electron microscope, X-ray diffraction (XRD) and microhardness tests, we evaluated how various physiological environments affect the hydration behavior and physical properties of mineral trioxide aggregate (MTA). We found that the microstructure of hydrated MTA consists of cubic and needle-like crystals. The former comprised the principal structure of MTA, whereas the later were less prominent and formed in the inter-grain spaces between the cubic crystals. MTA samples were hydrated in distilled water, normal saline, pH 7, and pH 5. However, no needle-like crystals were observed in the pH 5 specimens, and erosion of the cubic crystal surfaces was noted. XRD indicated a peak corresponding to Portlandite, a hydration product of MTA, and the peak decreased noticeably in the pH 5 group. The pH 5 specimens' microhardness was also significantly weaker compared to the other three groups (p<0.0001). These findings suggest that physiological environmental effects on MTA formation are determined, in part, by environmental pH and the presence of ions. In particular, an acidic environment of pH 5 adversely affects both the physical properties and the hydration behavior of MTA.

Identification of Clathrate Hydrates, Hexagonal Ice, Cubic Ice, and Liquid Water in Simulations: the CHILL+ Algorithm.

PubMed

Nguyen, Andrew H; Molinero, Valeria

2015-07-23

Clathrate hydrates and ice I are the most abundant crystals of water. The study of their nucleation, growth, and decomposition using molecular simulations requires an accurate and efficient algorithm that distinguishes water molecules that belong to each of these crystals and the liquid phase. Existing algorithms identify ice or clathrates, but not both. This poses a challenge for cases in which ice and hydrate coexist, such as in the synthesis of clathrates from ice and the formation of ice from clathrates during self-preservation of methane hydrates. Here we present an efficient algorithm for the identification of clathrate hydrates, hexagonal ice, cubic ice, and liquid water in molecular simulations. CHILL+ uses the number of staggered and eclipsed water-water bonds to identify water molecules in cubic ice, hexagonal ice, and clathrate hydrate. CHILL+ is an extension of CHILL (Moore et al. Phys. Chem. Chem. Phys. 2010, 12, 4124-4134), which identifies hexagonal and cubic ice but not clathrates. In addition to the identification of hydrates, CHILL+ significantly improves the detection of hexagonal ice up to its melting point. We validate the use of CHILL+ for the identification of stacking faults in ice and the nucleation and growth of clathrate hydrates. To our knowledge, this is the first algorithm that allows for the simultaneous identification of ice and clathrate hydrates, and it does so in a way that is competitive with respect to existing methods used to identify any of these crystals.

Course of Weaning from Prolonged Mechanical Ventilation after Cardiac Surgery

PubMed Central

Herlihy, James P.; Koch, Stephen M.; Jackson, Robert; Nora, Hope

2006-01-01

In order to determine the temporal pattern of weaning from mechanical ventilation for patients undergoing prolonged mechanical ventilation after cardiac surgery, we performed a retrospective review of 21 patients' weaning courses at our long-term acute care hospital. Using multiple regression analysis of an estimate of individual patients' percentage of mechanical ventilator support per day (%MVSD), we determined that 14 of 21 patients (67%) showed a statistically significant quadratic or cubic relationship between time and %MVSD. These patients showed little or no improvement in their ventilator dependence until a point in time when, abruptly, they began to make rapid progress (a “wean turning point”), after which they progressed to discontinuation of mechanical ventilation in a relatively short period of time. The other 7 patients appeared to have a similar weaning pattern, although the data were not statistically significant. Most patients in the study group weaned from the ventilator through a specific temporal pattern that is newly described herein. Data analysis suggested that the mechanism for the development of a wean turning point was improvement of pulmonary mechanics rather than improvement in gas exchange or respiratory load. Although these observations need to be confirmed by a prospective trial, they may have implications for weaning cardiac surgery patients from prolonged mechanical ventilation, and possibly for weaning a broader group of patients who require prolonged mechanical ventilation. PMID:16878611

Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn; Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018; Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn

The electronic structures of the cubic GdH{sub 3} are extensively investigated using the ab initio many-body GW calculations treating the Gd 4f electrons either in the core (4f-core) or in the valence states (4f-val). Different degrees of quasiparticle (QP) self-consistent calculations with the different starting points are used to correct the failures of the GGA/GGA + U/HSE03 calculations. In the 4f-core case, GGA + G{sub 0}W{sub 0} calculations give a fundamental band gap of 1.72 eV, while GGA+ GW{sub 0} or GGA + GW calculations present a larger band gap. In the 4f-val case, the nonlocal exchange-correlation (xc) functional HSE03 can account much better for the strong localizationmore » of the 4f states than the semilocal or Hubbard U corrected xc functional in the Kohn–Sham equation. We show that the fundamental gap of the antiferromagnetic (AFM) or ferromagnetic (FM) GdH{sub 3} can be opened up by solving the QP equation with improved starting point of eigenvalues and wave functions given by HSE03. The HSE03 + G{sub 0}W{sub 0} calculations present a fundamental band gap of 2.73 eV in the AFM configuration, and the results of the corresponding GW{sub 0} and GW calculations are 2.89 and 3.03 eV, respectively. In general, for the cubic structure, the fundamental gap from G{sub 0}W{sub 0} calculations in the 4f-core case is the closest to the real result. By G{sub 0}W{sub 0} calculations in the 4f-core case, we find that H or Gd defects can strongly affect the band structure, especially the H defects. We explain the mechanism in terms of the possible electron correlation on the hydrogen site. Under compression, the insulator-to-metal transition in the cubic GdH{sub 3} occurs around 40 GPa, which might be a satisfied prediction.« less

Computational study of Li2OHCl as a possible solid state battery material

NASA Astrophysics Data System (ADS)

Howard, Jason; Holzwarth, N. A. W.

Preparations of Li2OHCl have recently been experimentally studied as solid state Li ion electrolytes. A disordered cubic phase is known to be stable at temperatures T >35o C. Following previous ideas, first principles supercells are constructed with up to 320 atoms to model the cubic phase. First principles molecular dynamics simulations of the cubic phase show Li ion diffusion occuring on the t =10-12 s time scale, at temperatures as low as T = 400 K. The structure of the lower temperature phase (T <35o C) is not known in detail. A reasonable model of this structure is developed by using the tetragonal ideal structure found by first principles simulations and a model Hamiltonian to account for alternative orientations of the OH groups. Supported by NSF Grant DMR-1507942. Thanks to Zachary D. Hood of GaTech and ORNL for introducing these materials to us.

Integration Of 3D Geographic Information System (GIS) For Effective Waste Management Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rood, G.J.; Hecox, G.R.

2006-07-01

Soil remediation in response to the presence of residual radioactivity resulting from past MED/AEC activities is currently in progress under the Formerly Utilized Sites Remedial Action Program near the St. Louis, MO airport. During GY05, approximately 92,000 cubic meters (120,000 cubic yards) of radioactive soil was excavated, packaged and transported via rail for disposal at U.S. Ecology or Envirocare of Utah, LLC. To facilitate the management of excavation/transportation/disposal activities, a 3D GIS was developed for the site that was used to estimate the in-situ radionuclide activities, activities in excavation block areas, and shipping activities using a sum-of ratio (SOR) methodmore » for combining various radionuclide compounds into applicable transportation and disposal SOR values. The 3D GIS was developed starting with the SOR values for the approximately 900 samples from 90 borings. These values were processed into a three-dimensional (3D) point grid using kriging with nominal grid spacing of 1.5 by 1.5 meter horizontal by 0.3 meter vertical. The final grid, clipped to the area and soil interval above the planned base of excavation, consisted of 210,000 individual points. Standard GIS volumetric and spatial join procedures were used to calculate the volume of soil represented by each grid point, the base of excavation, depth below ground surface, elevation, surface elevation and SOR values for each point in the final grid. To create the maps needed for management, the point grid results were spatially joined to each excavation area in 0.9 meter (3 foot) depth intervals and the average SOR and total volumes were calculations. The final maps were color-coded for easy identification of areas above the specific transportation or disposal criteria. (authors)« less

Rogue wave train generation in a metamaterial induced by cubic-quintic nonlinearities and second-order dispersion

NASA Astrophysics Data System (ADS)

Essama, Bedel Giscard Onana; Atangana, Jacques; Frederick, Biya Motto; Mokhtari, Bouchra; Eddeqaqi, Noureddine Cherkaoui; Kofane, Timoleon Crepin

2014-09-01

We investigate the behavior of the electromagnetic wave that propagates in a metamaterial for negative index regime. Second-order dispersion and cubic-quintic nonlinearities are taken into account. The behavior obtained for negative index regime is compared to that observed for absorption regime. The collective coordinates technique is used to characterize the light pulse intensity profile at some frequency ranges. Five frequency ranges have been pointed out. The perfect combination of second-order dispersion and cubic nonlinearity leads to a robust soliton at each frequency range for negative index regime. The soliton peak power progressively decreases for absorption regime. Further, this peak power also decreases with frequency. We show that absorption regime can induce rogue wave trains generation at a specific frequency range. However, this rogue wave trains generation is maintained when the quintic nonlinearity comes into play for negative index regime and amplified for absorption regime at a specific frequency range. It clearly appears that rogue wave behavior strongly depends on the frequency and the regime considered. Furthermore, the stability conditions of the electromagnetic wave have also been discussed at frequency ranges considered for both negative index and absorption regimes.

Rogue wave train generation in a metamaterial induced by cubic-quintic nonlinearities and second-order dispersion.

PubMed

Essama, Bedel Giscard Onana; Atangana, Jacques; Frederick, Biya Motto; Mokhtari, Bouchra; Eddeqaqi, Noureddine Cherkaoui; Kofane, Timoleon Crepin

2014-09-01

We investigate the behavior of the electromagnetic wave that propagates in a metamaterial for negative index regime. Second-order dispersion and cubic-quintic nonlinearities are taken into account. The behavior obtained for negative index regime is compared to that observed for absorption regime. The collective coordinates technique is used to characterize the light pulse intensity profile at some frequency ranges. Five frequency ranges have been pointed out. The perfect combination of second-order dispersion and cubic nonlinearity leads to a robust soliton at each frequency range for negative index regime. The soliton peak power progressively decreases for absorption regime. Further, this peak power also decreases with frequency. We show that absorption regime can induce rogue wave trains generation at a specific frequency range. However, this rogue wave trains generation is maintained when the quintic nonlinearity comes into play for negative index regime and amplified for absorption regime at a specific frequency range. It clearly appears that rogue wave behavior strongly depends on the frequency and the regime considered. Furthermore, the stability conditions of the electromagnetic wave have also been discussed at frequency ranges considered for both negative index and absorption regimes.

Realizing zT of 2.3 in Ge1-x-y Sbx Iny Te via Reducing the Phase-Transition Temperature and Introducing Resonant Energy Doping.

PubMed

Hong, Min; Chen, Zhi-Gang; Yang, Lei; Zou, Yi-Chao; Dargusch, Matthew S; Wang, Hao; Zou, Jin

2018-03-01

GeTe with rhombohedral-to-cubic phase transition is a promising lead-free thermoelectric candidate. Herein, theoretical studies reveal that cubic GeTe has superior thermoelectric behavior, which is linked to (1) the two valence bands to enhance the electronic transport coefficients and (2) stronger enharmonic phonon-phonon interactions to ensure a lower intrinsic thermal conductivity. Experimentally, based on Ge 1- x Sb x Te with optimized carrier concentration, a record-high figure-of-merit of 2.3 is achieved via further doping with In, which induces the distortion of the density of states near the Fermi level. Moreover, Sb and In codoping reduces the phase-transition temperature to extend the better thermoelectric behavior of cubic GeTe to low temperature. Additionally, electronic microscopy characterization demonstrates grain boundaries, a high-density of stacking faults, and nanoscale precipitates, which together with the inevitable point defects result in a dramatically decreased thermal conductivity. The fundamental investigation and experimental demonstration provide an important direction for the development of high-performance Pb-free thermoelectric materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative study of crystallization process in metallic melts using ab initio molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Debela, Tekalign T.; Wang, X. D.; Cao, Q. P.; Zhang, D. X.; Jiang, J. Z.

2017-05-01

The crystallization process of liquid metals is studied using ab initio molecular dynamics simulations. The evolution of short-range order during quenching in Pb and Zn liquids is compared with body-centered cubic (bcc) Nb and V, and hexagonal closed-packed (hcp) Mg. We found that the fraction and type of the short-range order depends on the system under consideration, in which the icosahedral symmetry seems to dominate in the body-centered cubic metals. Although the local atomic structures in stable liquids are similar, liquid hcp-like Zn, bcc-like Nb and V can be deeply supercooled far below its melting point before crystallization while the supercooled temperature range in liquid Pb is limited. Further investigations into the nucleation process reveal the process of polymorph selection. In the body-centered cubic systems, the polymorph selection occurs in the supercooled state before the nucleation is initiated, while in the closed-packed systems it starts at the time of onset of crystallization. Atoms with bcc-like lattices in all studied supercooled liquids are always detected before the polymorph selection. It is also found that the bond orientational ordering is strongly correlated with the crystallization process in supercooled Zn and Pb liquids.

Antiretroviral Therapy for the Prevention of HIV-1 Transmission.

PubMed

Cohen, Myron S; Chen, Ying Q; McCauley, Marybeth; Gamble, Theresa; Hosseinipour, Mina C; Kumarasamy, Nagalingeswaran; Hakim, James G; Kumwenda, Johnstone; Grinsztejn, Beatriz; Pilotto, Jose H S; Godbole, Sheela V; Chariyalertsak, Suwat; Santos, Breno R; Mayer, Kenneth H; Hoffman, Irving F; Eshleman, Susan H; Piwowar-Manning, Estelle; Cottle, Leslie; Zhang, Xinyi C; Makhema, Joseph; Mills, Lisa A; Panchia, Ravindre; Faesen, Sharlaa; Eron, Joseph; Gallant, Joel; Havlir, Diane; Swindells, Susan; Elharrar, Vanessa; Burns, David; Taha, Taha E; Nielsen-Saines, Karin; Celentano, David D; Essex, Max; Hudelson, Sarah E; Redd, Andrew D; Fleming, Thomas R

2016-09-01

An interim analysis of data from the HIV Prevention Trials Network (HPTN) 052 trial showed that antiretroviral therapy (ART) prevented more than 96% of genetically linked infections caused by human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. ART was then offered to all patients with HIV-1 infection (index participants). The study included more than 5 years of follow-up to assess the durability of such therapy for the prevention of HIV-1 transmission. We randomly assigned 1763 index participants to receive either early or delayed ART. In the early-ART group, 886 participants started therapy at enrollment (CD4+ count, 350 to 550 cells per cubic millimeter). In the delayed-ART group, 877 participants started therapy after two consecutive CD4+ counts fell below 250 cells per cubic millimeter or if an illness indicative of the acquired immunodeficiency syndrome (i.e., an AIDS-defining illness) developed. The primary study end point was the diagnosis of genetically linked HIV-1 infection in the previously HIV-1-negative partner in an intention-to-treat analysis. Index participants were followed for 10,031 person-years; partners were followed for 8509 person-years. Among partners, 78 HIV-1 infections were observed during the trial (annual incidence, 0.9%; 95% confidence interval [CI], 0.7 to 1.1). Viral-linkage status was determined for 72 (92%) of the partner infections. Of these infections, 46 were linked (3 in the early-ART group and 43 in the delayed-ART group; incidence, 0.5%; 95% CI, 0.4 to 0.7) and 26 were unlinked (14 in the early-ART group and 12 in the delayed-ART group; incidence, 0.3%; 95% CI, 0.2 to 0.4). Early ART was associated with a 93% lower risk of linked partner infection than was delayed ART (hazard ratio, 0.07; 95% CI, 0.02 to 0.22). No linked infections were observed when HIV-1 infection was stably suppressed by ART in the index participant. The early initiation of ART led to a sustained decrease in genetically linked HIV-1 infections in sexual partners. (Funded by the National Institute of Allergy and Infectious Diseases; HPTN 052 ClinicalTrials.gov number, NCT00074581 .).

Unusual diffusive effects on the ESR of Nd 3+ ions in the tunable topologically nontrivial semimetal YBiPt

DOE PAGES

Lesseux, G. G.; Garitezi, T. M.; Rosa, P. F. S.; ...

2016-02-24

Electron spin resonance (ESR) of diluted Nd 3+ ions in the topologically nontrivial semimetallic (TNSM) YBiPt compound is reported. The cubic YBiPt compound is a non-centrosymmetric half Heusler material which crystallizes in the F43m space group. The low temperature Nd 3+ ESR spectra showed a g-value of 2.66(4) corresponding to amore » $${{\\Gamma}_{6}}$$ cubic crystal field Kramers' doublet ground state. Remarkably, the observed metallic and diffusive (Dysonian) Nd 3+ lineshape presented an unusual dependence with grain size, microwave power, Nd 3+ concentration and temperature. Furthermore, the spin dynamic of the localized Nd 3+ ions in YBiPt was found to be characteristic of a phonon-bottleneck regime. It is claimed that, in this regime for YBiPt, phonons are responsible for mediating the diffusion of the microwave energy absorbed at resonance by the Nd 3+ ions to the thermal bath throughout the skin depth ($$\\delta \\simeq 15$$ μm). We argue that this is only possible because of the existence of highly mobile conduction electrons inside the skin depth of YBiPt that are strongly coupled to the phonons by spin–orbit coupling. Thus, our unexpected ESR results point to a coexistence of metallic and insulating behaviors within the skin depth of YBiPt. This scenario is discussed in the light of the TNSM properties of this compound.« less

Hybrid density-functional calculations of phonons in LaCoO3

NASA Astrophysics Data System (ADS)

Gryaznov, Denis; Evarestov, Robert A.; Maier, Joachim

2010-12-01

Phonon frequencies at Γ point in nonmagnetic rhombohedral phase of LaCoO3 were calculated using density-functional theory with hybrid exchange correlation functional PBE0. The calculations involved a comparison of results for two types of basis functions commonly used in ab initio calculations, namely, the plane-wave approach and linear combination of atomic orbitals, as implemented in VASP and CRYSTAL computer codes, respectively. A good qualitative, but also within an error margin of less than 30%, a quantitative agreement was observed not only between the two formalisms but also between theoretical and experimental phonon frequency predictions. Moreover, the correlation between the phonon symmetries in cubic and rhombohedral phases is discussed in detail on the basis of group-theoretical analysis. It is concluded that the hybrid PBE0 functional is able to predict correctly the phonon properties in LaCoO3 .

An experimental study of symmetry lowering of analcime

NASA Astrophysics Data System (ADS)

Sugano, Neo; Kyono, Atsushi

2018-04-01

Single crystals of analcime were hydrothermally synthesized from a gel of analcime composition at 200 °C for 24 h. They were grown up to 100 μm in size with typical deltoidal icositetrahedron habit. The chemical composition determined by EPMA and TG analyses was Na0.84(Al0.89Si2.12)O6·1.04H2O. The single-crystal X-ray diffraction method was used to determine the symmetry and crystal structure of analcime. The analcime grown from a gel crystallized in cubic space group Ia3 d with lattice parameter a = 13.713(3) Å. In the cubic analcime, Si and Al cations were totally disordered over the framework T sites with site occupancy of Si:Al = 0.6871:0.3129(14). The single crystals of analcime with cubic symmetry were hydrothermally reheated at 200 °C in ultrapure water. After the hydrothermal treatment for 24 h, forbidden reflections for the cubic Ia3 d symmetry were observed. The reflection conditions led to an orthorhombic space group Ibca with lattice parameters a = 13.727(2) Å, b = 13.707(2) Å, and c = 13.707(2) Å. The unit-cell showed a slight distortion with ( a + b)/2 > c, yielding a flattened cell along c. In the orthorhombic analcime, Al exhibited a site preference for T11 site, which indicates that the Si/Al ordering over the framework T sites lowers the symmetry from cubic Ia3 d to orthorhombic Ibca. After the hydrothermal treatment for 48 h, reflections corresponding to orthorhombic space group Ibca were observed as well. The lattice parameters were a = 13.705(2) Å, b = 13.717(2) Å, and c = 13.706(2) Å, retaining the flattened cell shape with ( a + b)/2 > c. The Si and Al cations were further ordered among the framework T sites than the case of the hydrothermal treatment for 24 h. As a consequence, the Si/Al ordering was slightly but significantly accelerated with increasing the hydrothermal treatment time. During the hydrothermal reaction, however, chemical compositions were almost unchanged. The site occupancies of Na over the extra-framework sites remained unaffected with the heating time; thus, the hydrothermal heating influences the degree of ordering of Si and Al over the framework T sites rather than that of Na among the extra-framework sites.

The Rate and Shape of Change in Binge Eating Episodes and Weight: An Effectiveness Trial of Emotionally Focused Group Therapy for Binge-Eating Disorder.

PubMed

Compare, Angelo; Tasca, Giorgio A

2016-01-01

This study investigated the phases of change and the relationship between binge eating (BE) episodes and weight across 20 weeks of emotionally focused group therapy (EFGT) and combined therapy (CT) of EFGT plus dietary counselling for BE disorder. We used a non-randomized observational study design that included 118 obese adult patients with BE disorder who were treated by manualized therapy protocols. Participants were assigned to treatment condition (EFGT or CT) based on consensus among clinicians. Participants were assessed weekly during the 20 weeks of therapy for weight and BE episodes and at pre-treatment and 6 months post-treatment. Binge eating episodes and weight significantly declined during EFGT and CT. Compared with EFGT, CT resulted in more rapid weight loss across weeks of therapy. BE episodes and weight significantly covaried, and their positive association increased as sessions progressed. Change in BE episodes and weight during treatment was best modelled by a cubic growth curve showing a slow rate of change in early sessions, a faster rate of change in middle sessions and a slower rate of change in late sessions. This cubic modelling of change was associated with better outcomes 6 months post-treatment. Cubic modelling of change supported a three-stage model of EFGT and CT, and the cubic trajectory was associated with better outcomes at follow-up. The addition of dietary counselling to EFGT resulted in earlier response to treatment in terms of BE episodes and weight among those in the CT condition. Decline in binge eating (BE) episodes is related to decline in weight, and this relationship was greater towards the end of treatment. Emotionally focused group therapy plus dietary counselling that targets both affect regulation and nutritional problems resulted in faster rate of response early in treatment both in terms of BE episodes and weight. Combined emotionally focused group therapy and dietary counselling may provide clinicians with an additional approach to treating BE disorder. Copyright © 2014 John Wiley & Sons, Ltd.

Detecting local heterogeneity and ionization ability in the head group region of different lipidic phases using modified fluorescent probes

NASA Astrophysics Data System (ADS)

Abou-Zied, Osama K.; Zahid, N. Idayu; Khyasudeen, M. Faisal; Giera, David S.; Thimm, Julian C.; Hashim, Rauzah

2015-03-01

Local heterogeneity in lipid self-assembly is important for executing the cellular membrane functions. In this work, we chemically modified 2-(2'-hydroxyphenyl)benzoxazole (HBO) and attached a C8 alkyl chain in two different locations to probe the microscopic environment of four lipidic phases of dodecyl β-maltoside. The fluorescence change in HBO and the new probes (HBO-1 and HBO-2) shows that in all phases (micellar, hexagonal, cubic and lamellar) three HBO tautomeric species (solvated syn-enol, anionic, and closed syn-keto) are stable. The formation of multi tautomers reflects the heterogeneity of the lipidic phases. The results indicate that HBO and HBO-1 reside in a similar location within the head group region, whereas HBO-2 is slightly pushed away from the sugar-dominated area. The stability of the solvated syn-enol tautomer is due to the formation of a hydrogen bond between the OH group of the HBO moiety and an adjacent oxygen atom of a sugar unit. The detected HBO anions was proposed to be a consequence of this solvation effect where a hydrogen ion abstraction by the sugar units is enhanced. Our results point to a degree of local heterogeneity and ionization ability in the head group region as a consequence of the sugar amphoterism.

Interactive contour delineation and refinement in treatment planning of image‐guided radiation therapy

PubMed Central

Zhou, Wu

2014-01-01

The accurate contour delineation of the target and/or organs at risk (OAR) is essential in treatment planning for image‐guided radiation therapy (IGRT). Although many automatic contour delineation approaches have been proposed, few of them can fulfill the necessities of applications in terms of accuracy and efficiency. Moreover, clinicians would like to analyze the characteristics of regions of interests (ROI) and adjust contours manually during IGRT. Interactive tool for contour delineation is necessary in such cases. In this work, a novel approach of curve fitting for interactive contour delineation is proposed. It allows users to quickly improve contours by a simple mouse click. Initially, a region which contains interesting object is selected in the image, then the program can automatically select important control points from the region boundary, and the method of Hermite cubic curves is used to fit the control points. Hence, the optimized curve can be revised by moving its control points interactively. Meanwhile, several curve fitting methods are presented for the comparison. Finally, in order to improve the accuracy of contour delineation, the process of the curve refinement based on the maximum gradient magnitude is proposed. All the points on the curve are revised automatically towards the positions with maximum gradient magnitude. Experimental results show that Hermite cubic curves and the curve refinement based on the maximum gradient magnitude possess superior performance on the proposed platform in terms of accuracy, robustness, and time calculation. Experimental results of real medical images demonstrate the efficiency, accuracy, and robustness of the proposed process in clinical applications. PACS number: 87.53.Tf PMID:24423846

On piecewise interpolation techniques for estimating solar radiation missing values in Kedah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saaban, Azizan; Zainudin, Lutfi; Bakar, Mohd Nazari Abu

2014-12-04

This paper discusses the use of piecewise interpolation method based on cubic Ball and Bézier curves representation to estimate the missing value of solar radiation in Kedah. An hourly solar radiation dataset is collected at Alor Setar Meteorology Station that is taken from Malaysian Meteorology Deparment. The piecewise cubic Ball and Bézier functions that interpolate the data points are defined on each hourly intervals of solar radiation measurement and is obtained by prescribing first order derivatives at the starts and ends of the intervals. We compare the performance of our proposed method with existing methods using Root Mean Squared Errormore » (RMSE) and Coefficient of Detemination (CoD) which is based on missing values simulation datasets. The results show that our method is outperformed the other previous methods.« less

Design of wavefront coding optical system with annular aperture

NASA Astrophysics Data System (ADS)

Chen, Xinhua; Zhou, Jiankang; Shen, Weimin

2016-10-01

Wavefront coding can extend the depth of field of traditional optical system by inserting a phase mask into the pupil plane. In this paper, the point spread function (PSF) of wavefront coding system with annular aperture are analyzed. Stationary phase method and fast Fourier transform (FFT) method are used to compute the diffraction integral respectively. The OTF invariance is analyzed for the annular aperture with cubic phase mask under different obscuration ratio. With these analysis results, a wavefront coding system using Maksutov-Cassegrain configuration is designed finally. It is an F/8.21 catadioptric system with annular aperture, and its focal length is 821mm. The strength of the cubic phase mask is optimized with user-defined operand in Zemax. The Wiener filtering algorithm is used to restore the images and the numerical simulation proves the validity of the design.

Magneto-optical spectroscopy of ferromagnetic shape-memory Ni-Mn-Ga alloy

NASA Astrophysics Data System (ADS)

Veis, M.; Beran, L.; Zahradnik, M.; Antos, R.; Straka, L.; Kopecek, J.; Fekete, L.; Heczko, O.

2014-05-01

Magneto-optical properties of single crystal of Ni50.1Mn28.4Ga21.5 magnetic shape memory alloy in martensite and austenite phase were systematically studied. Crystal orientation was approximately along {100} planes of parent cubic austenite. At room temperature, the sample was in modulated 10M martensite phase and transformed to cubic austenite at 323 K. Spectral dependence of polar magneto-optical Kerr effect was obtained by generalized magneto-optical ellipsometry with rotating analyzer in the photon energy range from 1.2 to 4 eV, and from room temperature to temperature above the Curie point. The Kerr rotation spectra exhibit prominent features typical for complexes containing Mn atoms. Significant spectral changes during transformation to austenite can be explained by different optical properties caused by changes in density of states near the Fermi energy.

Distorted asymmetric cubic nanostructure of soluble fullerene crystals in efficient polymer:fullerene solar cells.

PubMed

Kim, Youngkyoo; Nelson, Jenny; Zhang, Tong; Cook, Steffan; Durrant, James R; Kim, Hwajeong; Park, Jiho; Shin, Minjung; Nam, Sungho; Heeney, Martin; McCulloch, Iain; Ha, Chang-Sik; Bradley, Donal D C

2009-09-22

We found that 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C(61) (PCBM) molecules make a distorted asymmetric body-centered cubic crystal nanostructure in the bulk heterojunction films of reigoregular poly(3-hexylthiophene) and PCBM. The wider angle of distortion in the PCBM nanocrystals was approximately 96 degrees , which can be assigned to the influence of the attached side group to the fullerene ball of PCBM to bestow solubility. Atom concentration analysis showed that after thermal annealing the PCBM nanocrystals do preferentially distribute above the layer of P3HT nanocrystals inside devices.

Point-to-point migration functions and gravity model renormalization: approaches to aggregation in spatial interaction modeling.

PubMed

Slater, P B

1985-08-01

Two distinct approaches to assessing the effect of geographic scale on spatial interactions are modeled. In the first, the question of whether a distance deterrence function, which explains interactions for one system of zones, can also succeed on a more aggregate scale, is examined. Only the two-parameter function for which it is found that distances between macrozones are weighted averaged of distances between component zones is satisfactory in this regard. Estimation of continuous (point-to-point) functions--in the form of quadrivariate cubic polynomials--for US interstate migration streams, is then undertaken. Upon numerical integration, these higher order surfaces yield predictions of interzonal and intrazonal movements at any scale of interest. Test of spatial stationarity, isotropy, and symmetry of interstate migration are conducted in this framework.

Long-term change analysis of satellite-based evapotranspiration over Indian vegetated surface

NASA Astrophysics Data System (ADS)

Gupta, Shweta; Bhattacharya, Bimal K.; Krishna, Akhouri P.

2016-05-01

In the present study, trend of satellite based annual evapotranspiration (ET) and natural forcing factors responsible for this were analyzed. Thirty years (1981-2010) of ET data at 0.08° grid resolution, generated over Indian region from opticalthermal observations from NOAA PAL and MODIS AQUA satellites, were used. Long-term data on gridded (0.5° x 0.5°) annual rainfall (RF), annual mean surface soil moisture (SSM) ERS scatterometer at 25 km resolution and annual mean incoming shortwave radiation from MERRA-2D reanalysis were also analyzed. Mann-Kendall tests were performed with time series data for trend analysis. Mean annual ET loss from Indian ago-ecosystem was found to be almost double (1100 Cubic Km) than Indian forest ecosystem (550 Cubic Km). Rainfed vegetation systems such as forest, rainfed cropland, grassland showed declining ET trend @ - 4.8, -0.6 &-0.4 Cubic Kmyr-1, respectively during 30 years. Irrigated cropland initially showed ET decline upto 1995 @ -0.8 cubic Kmyr-1 which could possibly be due to solar dimming followed by increasing ET @ 0.9 cubic Kmyr-1 after 1995. A cross-over point was detected between forest ET decline and ET increase in irrigated cropland during 2008. During 2001-2010, the four agriculturally important Indian states eastern, central, western and southern showed significantly increasing ET trend with S-score of 15-25 and Z-score of 1.09-2.9. Increasing ET in western and southern states was found to be coupled with increase in annual rainfall and SSM. But in eastern and central states no significant trend in rainfall was observed though significant increase in ET was noticed. The study recommended to investigate the influence of anthropogenic factors such as increase in area under irrigation, increased use of water for irrigation through ground water pumping, change in cropping pattern and cultivars on increasing ET.

Effect of lattice distortion on uranium magnetic moments in U4Ru7Ge6 studied by polarized neutron diffraction

NASA Astrophysics Data System (ADS)

Vališka, Michal; Klicpera, Milan; Doležal, Petr; Fabelo, Oscar; Stunault, Anne; Diviš, Martin; Sechovský, Vladimír

2018-03-01

In a cubic ferromagnet, small spontaneous lattice distortions are expected below the Curie temperature, but the phenomenon is usually neglected. This study focuses on such an effect in the U4Ru7Ge6 compound. Based on DFT calculations, we propose a lattice distortion from the cubic I m -3 m space group to a lower, rhombohedral, symmetry described by the R -3 m space group. The strong spin-orbit coupling of the uranium ions plays an essential role in lowering the symmetry, giving rise to two different U sites (U1 and U2). Using polarized neutron diffraction in applied magnetic fields of 1 and 9 T in the ordered state (1.9 K ) and in the paramagnetic state (20 K ), we bring convincing experimental evidence of this splitting of the U sites, with different magnetic moments. The data have been analyzed both by maximum entropy calculations and by a direct fit in the dipolar approximation. In the ordered phase, the μL/μS ratio of the orbital and spin moments on the U2 site is remarkably lower than for the free U3 + or U4 + ion, which points to a strong hybridization of the U 5 f wave functions with the 4 d wave functions of the surrounding Ru. On the U1 site, the μL/μS ratio exhibits an unexpectedly low value: the orbital moment is almost quenched, like in metallic α -uranium. As a further evidence of the 5 f -4 d hybridization in the U4Ru7Ge6 system, we observe the absence of a magnetic moment on the Ru1 site, but a rather large induced moment on the Ru2 site, which is in closer coordination with both U positions. Very similar results are obtained at 20 K in the ferromagnetic regime induced by the magnetic field of 9 T . This shows that applying a strong magnetic field above the Curie temperature also leads to the splitting of the uranium sites, which further demonstrates the intimate coupling of the magnetic ordering and structural distortion. We propose that the difference between the magnetic moment on the U1 and U2 sites results from the strong spin-orbit interaction with different local point symmetries.

Pressure-induced phase transitions of β-type pyrochlore CsTaWO 6

DOE PAGES

Zhang, F. X.; Tracy, C. L.; Shamblin, J.; ...

2016-09-30

The β-type pyrochlore CsTaWO 6 was studied by synchrotron X-ray diffraction (XRD) and Raman scattering methods up to pressures of 43 GPa using a diamond anvil cell (DAC). With increasing pressure, the cubic pyrochlore in space group of Fd-3¯m with combining macron]m transforms to an orthorhombic structure (space group: Pnma) at 5.9 GPa and then to a monoclinic structure (space group: P2 1/c) at ~18 GPa. The structural evolution in CsTaWO 6 is a continuous process and experimental results suggest that the initial cubic phase has a tetragonal distortion at ambient conditions. Both XRD and Raman measurements indicate that themore » pressure-induced phase transitions in CsTaWO 6 are reversible. Lastly, these results may provide a structural explanation of previous experimental resistivity measurement results for the isostructural superconductor K(Cs)Os 2O 6 at high pressure conditions.« less

Pressure-induced phase transitions of β-type pyrochlore CsTaWO 6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, F. X.; Tracy, C. L.; Shamblin, J.

The β-type pyrochlore CsTaWO 6 was studied by synchrotron X-ray diffraction (XRD) and Raman scattering methods up to pressures of 43 GPa using a diamond anvil cell (DAC). With increasing pressure, the cubic pyrochlore in space group of Fd-3¯m with combining macron]m transforms to an orthorhombic structure (space group: Pnma) at 5.9 GPa and then to a monoclinic structure (space group: P2 1/c) at ~18 GPa. The structural evolution in CsTaWO 6 is a continuous process and experimental results suggest that the initial cubic phase has a tetragonal distortion at ambient conditions. Both XRD and Raman measurements indicate that themore » pressure-induced phase transitions in CsTaWO 6 are reversible. Lastly, these results may provide a structural explanation of previous experimental resistivity measurement results for the isostructural superconductor K(Cs)Os 2O 6 at high pressure conditions.« less

Cosmological perturbations in inflation and in de Sitter space

NASA Astrophysics Data System (ADS)

Pimentel, Guilherme Leite

This thesis focuses on various aspects of inflationary fluctuations. First, we study gravitational wave fluctuations in de Sitter space. The isometries of the spacetime constrain to a few parameters the Wheeler-DeWitt wavefunctional of the universe, to cubic order in fluctuations. At cubic order, there are three independent terms in the wavefunctional. From the point of view of the bulk action, one term corresponds to Einstein gravity, and a new term comes from a cubic term in the curvature tensor. The third term is a pure phase and does not give rise to a new shape for expectation values of graviton fluctuations. These results can be seen as the leading order non-gaussian contributions in a slow-roll expansion for inflationary observables. We also use the wavefunctional approach to explain a universal consistency condition of n-point expectation values in single field inflation. This consistency condition relates a soft limit of an n-point expectation value to ( n-1)-point expectation values. We show how these conditions can be easily derived from the wavefunctional point of view. Namely, they follow from the momentum constraint of general relativity, which is equivalent to the constraint of spatial diffeomorphism invariance. We also study expectation values beyond tree level. We show that subhorizon fluctuations in loop diagrams do not generate a mass term for superhorizon fluctuations. Such a mass term could spoil the predictivity of inflation, which is based on the existence of properly defined field variables that become constant once their wavelength is bigger than the size of the horizon. Such a mass term would be seen in the two point expectation value as a contribution that grows linearly with time at late times. The absence of this mass term is closely related to the soft limits studied in previous chapters. It is analogous to the absence of a mass term for the photon in quantum electrodynamics, due to gauge symmetry. Finally, we use the tools of holography and entanglement entropy to study superhorizon correlations in quantum field theories in de Sitter space. The entropy has interesting terms that have no equivalent in flat space field theories. These new terms are due to particle creation in an expanding universe. The entropy is calculated directly for free massive scalar theories. For theories with holographic duals, it is determined by the area of some extremal surface in the bulk geometry. We calculate the entropy for different classes of holographic duals. For one of these classes, the holographic dual geometry is an asymptotically Anti-de Sitter space that decays into a crunching cosmology, an open Friedmann-Robertson-Walker universe. The extremal surface used in the calculation of the entropy lies almost entirely on the slice of maximal scale factor of the crunching cosmology.

Morphologies of precise polyethylene-based acid copolymers and ionomers

NASA Astrophysics Data System (ADS)

Buitrago, C. Francisco

Acid copolymers and ionomers are polymers that contain a small fraction of covalently bound acidic or ionic groups, respectively. For the specific case of polyethylene (PE), acid and ionic pendants enhance many of the physical properties such as toughness, adhesion and rheological properties. These improved properties result from microphase separated aggregates of the polar pendants in the non-polar PE matrix. Despite the widespread industrial use of these materials, rigorous chemical structure---morphology---property relationships remain elusive due to the inevitable structural heterogeneities in the historically-available acid copolymers and ionomers. Recently, precise acid copolymers and ionomers were successfully synthesized by acyclic diene metathesis (ADMET) polymerization. These precise materials are linear, high molecular weight PEs with pendant acid or ionic functional groups separated by a precisely controlled number of carbon atoms. The morphologies of nine precise acid copolymers and eleven precise ionomers were investigated by X-ray scattering, solid-state 13C nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). For comparison, the morphologies of linear PEs with pseudo-random placement of the pendant groups were also studied. Previous studies of precise copolymers with acrylic acid (AA) found that the microstructural precision produces a new morphology in which PE crystals drive the acid aggregates into layers perpendicular to the chain axes and presumably at the interface between crystalline and amorphous phases. In this dissertation, a second new morphology for acid copolymers is identified in which the aggregates arrange on cubic lattices. The fist report of a cubic morphology was observed at room and elevated temperatures for a copolymer functionalized with two phosphonic acid (PA) groups on every 21st carbon atom. The cubic lattice has been identified as face-centered cubic (FCC). Overall, three morphology types have been identified for precise acid copolymers and ionomers at room temperature: (1) liquid-like order of aggregates dispersed throughout an amorphous PE matrix, (2) one-dimensional long-range order of aggregates in layers coexisting with PE crystals, and (3) three-dimensional periodicity of aggregates in cubic lattices in a PE matrix featuring defective packing. The liquid-like morphology is a result of high content of acid or ionic substituents deterring PE crystallinity due to steric hindrance. The layered morphology occurs when the content of pendants is low and the PE segments are long enough to crystallize. The cubic morphologies occur in precise copolymers with geminal substitution of phosphonic acid (PA) groups and long, flexible PE segments. At temperatures above the thermal transitions of the PE matrix, all but one material present a liquid-like morphology. Those conditions are ideal to study the evolution of the interaggregate spacing (d*) in X-ray scattering as a function of PE segment length between pendants, pendant type and pendant architecture (specifically, mono or geminal substitution). Also at elevated temperatures, the morphologies of precise acrylic acid (AA) copolymers and ionomers were investigated further via atomistic molecular dynamics (MD) simulations. The simulations complement X-ray scattering by providing real space visualization of the aggregates, demonstrating the occurrence of isolated, string-like and even percolated aggregate structures. This is the first dissertation completely devoted to the morphology of precise acid copolymers and precise ionomers. The complete analysis of the morphologies in these novel materials provides new insights into the shapes of aggregates in acid copolymers and ionomers in general. A key aspect of this thesis is the complementary use of experimental and simulation methods to unlock a wealth of new understanding.

40 CFR Table 3 to Subpart Ppp of... - Group 1 Storage Vessels at Existing and New Affected Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Group 1 Storage Vessels at Existing and... Polyether Polyols Production Pt. 63, Subpt. PPP, Table 3 Table 3 to Subpart PPP of Part 63—Group 1 Storage Vessels at Existing and New Affected Sources Vessel capacity(cubic meters) Vapor Pressure a (kilopascals...

40 CFR Table 3 to Subpart Ppp of... - Group 1 Storage Vessels at Existing and New Affected Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Group 1 Storage Vessels at Existing and... Polyether Polyols Production Pt. 63, Subpt. PPP, Table 3 Table 3 to Subpart PPP of Part 63—Group 1 Storage Vessels at Existing and New Affected Sources Vessel capacity(cubic meters) Vapor Pressure a (kilopascals...

Proceedings of the Scientific Conference on Obscuration and Aerosol Research Held in Aberdeen Proving Ground, Maryland on June 22-25, 1992

DTIC Science & Technology

1993-06-01

Qad and the other, which can be considered due to edges effects, Qcd . 2.2.1 Extended Anomalous Diffraction The anomalous diffraction formula is derived...particle with an array of N point dipoles on a cubic lattice . The polarization of each dipole is found by solving a self- consistent set of linear

40 CFR 63.7824 - What test methods and other procedures must I use to establish and demonstrate initial compliance...

Code of Federal Regulations, 2010 CFR

2010-07-01

... select sampling port locations and the number of traverse points. Sampling ports must be located at the... Method 25 (40 CFR part 60, appendix A), milligrams per dry standard cubic meters (mg/dscm) for each day... = Conversion factor (mg/lb); and K = Daily production rate of sinter, tons/hr. (4) Continue the sampling and...

40 CFR 63.7824 - What test methods and other procedures must I use to establish and demonstrate initial compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... select sampling port locations and the number of traverse points. Sampling ports must be located at the... Method 25 (40 CFR part 60, appendix A), milligrams per dry standard cubic meters (mg/dscm) for each day... = Conversion factor (mg/lb); and K = Daily production rate of sinter, tons/hr. (4) Continue the sampling and...

40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

Code of Federal Regulations, 2011 CFR

2011-07-01

... appendix A to 40 CFR part 60: (i) Method 1 to select sampling port locations and the number of traverse points. Sampling ports must be located at the outlet of the control device and prior to any releases to... = Concentration of chlorine or hydrochloric acid in the gas stream, milligrams per dry standard cubic meter (mg...

40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

Code of Federal Regulations, 2010 CFR

2010-07-01

... appendix A to 40 CFR part 60: (i) Method 1 to select sampling port locations and the number of traverse points. Sampling ports must be located at the outlet of the control device and prior to any releases to... = Concentration of chlorine or hydrochloric acid in the gas stream, milligrams per dry standard cubic meter (mg...

A net volume equation for Northeastern Minnesota.

Treesearch

Gerhard K. Raile

1980-01-01

Describes a net volume equation for northeastern Minnesota developed as part of the 1977 Minnesota Forest Inventory. Equation coefficients are presented by species groupings for both cubic foot and board foot volumes for five tree classes.

Polymorphism of the hydroxide perovskite Ga(OH)3 and possible proton-driven transformational behaviour

NASA Astrophysics Data System (ADS)

Welch, M. D.; Kleppe, A. K.

2016-07-01

The crystal structure of hydroxide perovskite Ga(OH)3, the mineral söhngeite, has been determined for a natural sample by single-crystal XRD in space group P42/ nmc to R 1 = 0.031, wR 2 = 0.071, GoF = 1.208, and for comparison also in space group P42/ n to R 1 = 0.031, wR 2 = 0.073, GoF = 1.076. Unit cell parameters are a = 7.4546(2) Å, c = 7.3915(2) Å, V = 410.75(2) Å3. The two structures are very similar and both have tilt system a + a + c -. The approximate positions of all H atoms in each structure have been refined. In the P42/ nmc structure all five H sites are half-occupied, whereas in the P42/ n structure four sites are half-occupied and one is fully occupied. The presence of five non-equivalent OH groups in söhngeite is confirmed by single-crystal Raman spectroscopy, but does not allow a choice between these two space groups to be made. There is only a single very weak violator of the c-glide of P42/ nmc and the two refined structures are essentially the same, but are significantly different from that of the original description in which orthorhombic space group Pmn21 was reported with corresponding tilt system a 0 a 0 c +. It is argued here that such a structure is very implausible for a hydroxide perovskite. On heating söhngeite to 423 K, transformation to a cubic structure with Imbar{3} symmetry ( a + a + a +) of the aristotype occurs. This cubic phase was recovered on cooling to 293 K without back-transformation to the tetragonal polymorph. As there is no continuous group/subgroup pathway from P42/ nmc (or P42/ n) to Imbar{3}, the transformation must be first-order, which is consistent with the large hysteresis observed. The change from the tetragonal to cubic structures involves a change in tilt system a + a + c - → a + a + a +, with a significant reconfiguration of hydrogen-bonding topology. The very different tilt systems and hydrogen-bonding configurations of the two polymorphs are responsible for hysteresis and metastable preservation of the cubic phase at 293 K. As the Ga(OH)6 octahedra of the low- and high- T polymorphs are very similar it is inferred that the transformation is driven by proton behaviour, presumably involving proton re-ordering.

Reply to “Structural and magnetic behavior of the cubic oxyfluoride SrFeO{sub 2}F studied by neutron diffraction”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clemens, Oliver, E-mail: oliver.clemens@kit.edu; Karlsruher Institut für Technologie, Institut für Nanotechnologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen; Berry, Frank J.

2015-03-15

In this article we comment on the results published by Thompson et al. (, J. Solid State Chem. 219 (2014) 173–178) on the crystal structure of SrFeO{sub 2}F, who claim the compound to crystallize in the cubic space group Pm-3m. We give a more detailed explanation of the determination of our previously reported structural model with Imma symmetry (Clemens et al., J. Solid State Chem. 206 (2013) 158–169), with addition of variable temperature XRD measurements with high counting time to provide unambiguous evidence for the Imma model being correct for our sample. - Graphical abstract: The crystal structure of SrFeO{submore » 2}F is discussed with regards to previous reports. - Highlights: • SrFeO{sub 2}F was synthesized by polymer based fluorination of SrFeO{sub 3}. • Evaluation of the diffraction data shows a pseudocubic cell metric. • Superstructure reflections at low d-spacings indicate deviation from cubic symmetry. • The phase transition temperature from orthorhombic to cubic was determined using variable temperature X-ray diffraction. • Results published by Thompson et al. are critically discussed with respect to those observations.« less

Signal-to-noise ratio estimation using adaptive tuning on the piecewise cubic Hermite interpolation model for images.

PubMed

Sim, K S; Yeap, Z X; Tso, C P

2016-11-01

An improvement to the existing technique of quantifying signal-to-noise ratio (SNR) of scanning electron microscope (SEM) images using piecewise cubic Hermite interpolation (PCHIP) technique is proposed. The new technique uses an adaptive tuning onto the PCHIP, and is thus named as ATPCHIP. To test its accuracy, 70 images are corrupted with noise and their autocorrelation functions are then plotted. The ATPCHIP technique is applied to estimate the uncorrupted noise-free zero offset point from a corrupted image. Three existing methods, the nearest neighborhood, first order interpolation and original PCHIP, are used to compare with the performance of the proposed ATPCHIP method, with respect to their calculated SNR values. Results show that ATPCHIP is an accurate and reliable method to estimate SNR values from SEM images. SCANNING 38:502-514, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Optical solitons, nonlinear self-adjointness and conservation laws for the cubic nonlinear Shrödinger's equation with repulsive delta potential

NASA Astrophysics Data System (ADS)

Baleanu, Dumitru; Inc, Mustafa; Aliyu, Aliyu Isa; Yusuf, Abdullahi

2017-11-01

In this paper, the complex envelope function ansatz method is used to acquire the optical solitons to the cubic nonlinear Shrödinger's equation with repulsive delta potential (δ-NLSE). The method reveals dark and bright optical solitons. The necessary constraint conditions which guarantee the existence of the solitons are also presented. We studied the δ-NLSE by analyzing a system of partial differential equations (PDEs) obtained by decomposing the equation into real and imaginary components. We derive the Lie point symmetry generators of the system and prove that the system is nonlinearly self-adjoint with an explicit form of a differential substitution satisfying the nonlinear self-adjoint condition. Then we use these facts to establish a set of conserved vectors for the system using the general Cls theorem presented by Ibragimov. Some interesting figures for the acquired solutions are also presented.

On the conditions for the onset of nonlinear chirping structures in NSTX

NASA Astrophysics Data System (ADS)

Duarte, Vinicius; Podesta, Mario; Berk, Herbert; Gorelenkov, Nikolai

2015-11-01

The nonlinear dynamics of phase space structures is a topic of interest in tokamak physics in connection with fast ion loss mechanisms. The onset of phase-space holes and clumps has been theoretically shown to be associated with an explosive solution of an integro-differential, nonlocal cubic equation that governs the early mode amplitude evolution in the weakly nonlinear regime. The existence and stability of the solutions of the cubic equation have been theoretically studied as a function of Fokker-Planck coefficients for the idealized case of a single resonant point of a localized mode. From realistic computations of NSTX mode structures and resonant surfaces, we calculate effective pitch angle scattering and slowing-down (drag) collisional coefficients and analyze NSTX discharges for different cases with respect to chirping experimental observation. Those results are confronted to the theory that predicts the parameters region that allow for chirping to take place.

Lattice dynamics and the nature of structural transitions in organolead halide perovskites

DOE PAGES

Comin, Riccardo; Crawford, Michael K.; Said, Ayman H.; ...

2016-09-09

Organolead halide perovskites are a family of hybrid organic-inorganic compounds whose remark- able optoelectronic properties have been under intensive scrutiny in recent years. Here we use inelastic X-ray scattering to study low-energy lattice excitations in single crystals of methylammonium lead iodide and bromide perovskites. Our ndings conrm the displacive nature of the cubic-to- tetragonal phase transition, which is further shown, using neutron and x-ray diraction, to be close to a tricritical point. The experimental sound speed, around 100-200 m/s, suggests that electron- phonon scattering is likely a limiting factor for further improvements in carrier mobility. Lastly, we detect quasistatic symmetry-breakingmore » nanodomains persisting well into the high-temperature cubic phase, possibly stabilized by local defects. These ndings reveal key structural properties of these materials, but also bear important implications for carrier dynamics across an extended temperature range relevant for photovoltaic applications.« less

A two dimensional interface element for coupling of independently modeled three dimensional finite element meshes and extensions to dynamic and non-linear regimes

NASA Technical Reports Server (NTRS)

Aminpour, Mohammad

1995-01-01

The work reported here pertains only to the first year of research for a three year proposal period. As a prelude to this two dimensional interface element, the one dimensional element was tested and errors were discovered in the code for built-up structures and curved interfaces. These errors were corrected and the benchmark Boeing composite crown panel was analyzed successfully. A study of various splines led to the conclusion that cubic B-splines best suit this interface element application. A least squares approach combined with cubic B-splines was constructed to make a smooth function from the noisy data obtained with random error in the coordinate data points of the Boeing crown panel analysis. Preliminary investigations for the formulation of discontinuous 2-D shell and 3-D solid elements were conducted.

Lattice dynamics and the nature of structural transitions in organolead halide perovskites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comin, Riccardo; Crawford, Michael K.; Said, Ayman H.

Organolead halide perovskites are a family of hybrid organic-inorganic compounds whose remark- able optoelectronic properties have been under intensive scrutiny in recent years. Here we use inelastic X-ray scattering to study low-energy lattice excitations in single crystals of methylammonium lead iodide and bromide perovskites. Our ndings conrm the displacive nature of the cubic-to- tetragonal phase transition, which is further shown, using neutron and x-ray diraction, to be close to a tricritical point. The experimental sound speed, around 100-200 m/s, suggests that electron- phonon scattering is likely a limiting factor for further improvements in carrier mobility. Lastly, we detect quasistatic symmetry-breakingmore » nanodomains persisting well into the high-temperature cubic phase, possibly stabilized by local defects. These ndings reveal key structural properties of these materials, but also bear important implications for carrier dynamics across an extended temperature range relevant for photovoltaic applications.« less

Partial regularity of weak solutions to a PDE system with cubic nonlinearity

NASA Astrophysics Data System (ADS)

Liu, Jian-Guo; Xu, Xiangsheng

2018-04-01

In this paper we investigate regularity properties of weak solutions to a PDE system that arises in the study of biological transport networks. The system consists of a possibly singular elliptic equation for the scalar pressure of the underlying biological network coupled to a diffusion equation for the conductance vector of the network. There are several different types of nonlinearities in the system. Of particular mathematical interest is a term that is a polynomial function of solutions and their partial derivatives and this polynomial function has degree three. That is, the system contains a cubic nonlinearity. Only weak solutions to the system have been shown to exist. The regularity theory for the system remains fundamentally incomplete. In particular, it is not known whether or not weak solutions develop singularities. In this paper we obtain a partial regularity theorem, which gives an estimate for the parabolic Hausdorff dimension of the set of possible singular points.

Magneto-optical spectroscopy of ferromagnetic shape-memory Ni-Mn-Ga alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veis, M., E-mail: veis@karlov.mff.cuni.cz; Beran, L.; Zahradnik, M.

2014-05-07

Magneto-optical properties of single crystal of Ni{sub 50.1}Mn{sub 28.4}Ga{sub 21.5} magnetic shape memory alloy in martensite and austenite phase were systematically studied. Crystal orientation was approximately along (100) planes of parent cubic austenite. At room temperature, the sample was in modulated 10M martensite phase and transformed to cubic austenite at 323 K. Spectral dependence of polar magneto-optical Kerr effect was obtained by generalized magneto-optical ellipsometry with rotating analyzer in the photon energy range from 1.2 to 4 eV, and from room temperature to temperature above the Curie point. The Kerr rotation spectra exhibit prominent features typical for complexes containing Mn atoms. Significantmore » spectral changes during transformation to austenite can be explained by different optical properties caused by changes in density of states near the Fermi energy.« less

Microstructural characterization of random packings of cubic particles

PubMed Central

Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

2016-01-01

Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO2 sequestration in rock, and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. The results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities. The maximum packing fraction is about 0.57. PMID:27725736

High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

NASA Astrophysics Data System (ADS)

Ueland, B. G.; Saunders, S. M.; Bud'Ko, S. L.; Schmiedeshoff, G. M.; Canfield, P. C.; Kreyssig, A.; Goldman, A. I.

YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below T* = 0 . 7 K, fragile antiferromagnetic order below TN = 0 . 4 K, a Kondo temperature of TK ~ 1 K, and crystalline-electric-field splitting (CEF) on the order of E /kB = 1 - 10 K. Its lattice is face-centered cubic at ambient temperature, but certain data, particularly those from studies aimed at determining the CEF level scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-energy x-ray diffraction experiments which show that, within our experimental resolution of ~ 6 - 10 ×10-5 Å, no structural phase transition occurs between 1 . 5 and 50 K. Despite this result, we demonstrate that the compound's thermal expansion may be modeled using CEF level schemes appropriate for Yb3+ residing on a site with either cubic or less than cubic point symmetry. Work at the Ames Laboratory was supported by the US DOE, BES, DMSE, under Contract No. DE-AC02-07CH11358. Work at Occidental College was supported by the NSF under DMR-1408598. This research used resources at the Advanced Photon Source a US DOE, Office of Science, User Facility.

Phase degradation in BxGa1-xN films grown at low temperature by metalorganic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Gunning, Brendan P.; Moseley, Michael W.; Koleske, Daniel D.; Allerman, Andrew A.; Lee, Stephen R.

2017-04-01

Using metalorganic vapor phase epitaxy, a comprehensive study of BxGa1-xN growth on GaN and AlN templates is described. BGaN growth at high-temperature and high-pressure results in rough surfaces and poor boron incorporation efficiency, while growth at low-temperature and low-pressure (750-900 °C and 20 Torr) using nitrogen carrier gas results in improved surface morphology and boron incorporation up to 7.4% as determined by nuclear reaction analysis. However, further structural analysis by transmission electron microscopy and x-ray pole figures points to severe degradation of the high boron composition films, into a twinned cubic structure with a high density of stacking faults and little or no room temperature photoluminescence emission. Films with <1% triethylboron (TEB) flow show more intense, narrower x-ray diffraction peaks, near-band-edge photoluminescence emission at 362 nm, and primarily wurtzite-phase structure in the x-ray pole figures. For films with >1% TEB flow, the crystal structure becomes dominated by the cubic phase. Only when the TEB flow is zero (pure GaN), does the cubic phase entirely disappear from the x-ray pole figure, suggesting that under these growth conditions even very low boron compositions lead to mixed crystalline phases.

Microstructural characterization of random packings of cubic particles

DOE PAGES

Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

2016-10-11

Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO 2 sequestration inmore » rock, and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. Here, the results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities.« less

A prototype experiment for cooperative monitoring of nuclear reactors with cubic meter scale antineutrino detectors

NASA Astrophysics Data System (ADS)

Bernstein, A.; Allen, M.; Bowden, N.; Brennan, J.; Carr, D. J.; Estrada, J.; Hagmann, C.; Lund, J. C.; Madden, N. W.; Winant, C. D.

2005-09-01

Our Lawrence Livermore National Laboratory/Sandia National Laboratories collaboration has deployed a cubic-meter-scale antineutrino detector to demonstrate non-intrusive and automatic monitoring of the power levels and plutonium content of a nuclear reactor. Reactor monitoring of this kind is required for all non-nuclear weapons states under the Nuclear Nonproliferation Treaty (NPT), and is implemented by the International Atomic Energy Agency (IAEA). Since the antineutrino count rate and energy spectrum depend on the relative yields of fissioning isotopes in the reactor core, changes in isotopic composition can be observed without ever directly accessing the core. Data from a cubic meter scale antineutrino detector, coupled with the well-understood principles that govern the core's evolution in time, can be used to determine whether the reactor is being operated in an illegitimate way. Our group has deployed a detector at the San Onofre reactor site in California to demonstrate this concept. This paper describes the concept and shows preliminary results from 8 months of operation.

In situ synthesis and characterization of uranium carbide using high temperature neutron diffraction

NASA Astrophysics Data System (ADS)

Reiche, H. Matthias; Vogel, Sven C.; Tang, Ming

2016-04-01

We investigated the formation of UCx from UO2+x and graphite in situ using neutron diffraction at high temperatures with particular focus on resolving the conflicting reports on the crystal structure of non-quenchable cubic UC2. The agents were UO2 nanopowder, which closely imitates nano grains observed in spent reactor fuels, and graphite powder. In situ neutron diffraction revealed the onset of the UO2 + 2C → UC + CO2 reaction at 1440 °C, with its completion at 1500 °C. Upon further heating, carbon diffuses into the uranium carbide forming C2 groups at the octahedral sites. This resulting high temperature cubic UC2 phase is similar to the NaCl-type structure as proposed by Bowman et al. Our novel experimental data provide insights into the mechanism and kinetics of formation of UC as well as characteristics of the high temperature cubic UC2 phase which agree with proposed rotational rehybridization found from simulations by Wen et al.

Membrane curvature stress and antibacterial activity of lactoferricin derivatives.

PubMed

Zweytick, Dagmar; Tumer, Sabine; Blondelle, Sylvie E; Lohner, Karl

2008-05-02

We have studied correlation of non-lamellar phase formation and antimicrobial activity of two cationic amphipathic peptides, termed VS1-13 and VS1-24 derived from a fragment (LF11) of human lactoferricin on Escherichia coli total lipid extracts. Compared to LF11, VS1-13 exhibits minor, but VS1-24 significantly higher antimicrobial activity. X-ray experiments demonstrated that only VS1-24 decreased the onset of cubic phase formation of dispersions of E. coli lipid extracts, significantly, down to physiological relevant temperatures. Cubic structures were identified to belong to the space groups Pn3m and Im3m. Formation of latter is enhanced in the presence of VS1-24. Additionally, the presence of this peptide caused membrane thinning in the fluid phase, which may promote cubic phase formation. VS1-24 containing a larger hydrophobic volume at the N-terminus than its less active counterpart VS1-13 seems to increase curvature stress in the bilayer and alter the behaviour of the membrane significantly enhancing disruption.

Wisconsin's Forests 2009

Treesearch

Charles H. Perry; Vern A. Everson; Brett J. Butler; Susan J. Crocker; Sally E. Dahir; Andrea L. Diss-Torrance; Grant M Domke; Dale D. Gormanson; Sarah K. Herrick; Steven S. Hubbard; Terry R. Mace; Patrick D. Miles; Mark D. Nelson; Richard B. Rodeout; Luke T. Saunders; Kirk M. Stueve; Barry T. Wilson; Christopher W. Woodall

2012-01-01

The second full annual inventory of Wisconsin's forests reports more than 16.7 million acres of forest land with an average volume of more than 1,400 cubic feet per acre. Forest land is dominated by the oak/hickory forest-type group, which occupies slightly more than one quarter of the total forest land area; the maple/beech/birch forest-type group occupies an...

Silicon displacement threshold energy determined by electron paramagnetic resonance and positron annihilation spectroscopy in cubic and hexagonal polytypes of silicon carbide

NASA Astrophysics Data System (ADS)

Kerbiriou, X.; Barthe, M.-F.; Esnouf, S.; Desgardin, P.; Blondiaux, G.; Petite, G.

2007-05-01

Both for electronic and nuclear applications, it is of major interest to understand the properties of point defects into silicon carbide (SiC). Low energy electron irradiations are supposed to create primary defects into materials. SiC single crystals have been irradiated with electrons at two beam energies in order to investigate the silicon displacement threshold energy into SiC. This paper presents the characterization of the electron irradiation-induced point defects into both polytypes hexagonal (6H) and cubic (3C) SiC single crystals by using both positron annihilation spectroscopy (PAS) and electron paramagnetic resonance (EPR). The nature and the concentration of the generated point defects depend on the energy of the electron beam and the polytype. After an electron irradiation at an energy of 800 keV vSi mono-vacancies and vSi-vC di-vacancies are detected in both 3C and 6H-SiC polytypes. On the contrary, the nature of point defects detected after an electron irradiation at 190 keV strongly depends on the polytype. Into 6H-SiC crystals, silicon Frenkel pairs vSi-Si are detected whereas only carbon vacancy related defects are detected into 3C-SiC crystals. The difference observed in the distribution of defects detected into the two polytypes can be explained by the different values of the silicon displacement threshold energies for 3C and 6H-SiC. By comparing the calculated theoretical numbers of displaced atoms with the defects numbers measured using EPR, the silicon displacement threshold energy has been estimated to be slightly lower than 20 eV in the 6H polytype and close to 25 eV in the 3C polytype.

Extensions of D-optimal Minimal Designs for Symmetric Mixture Models.

PubMed

Li, Yanyan; Raghavarao, Damaraju; Chervoneva, Inna

2017-01-01

The purpose of mixture experiments is to explore the optimum blends of mixture components, which will provide desirable response characteristics in finished products. D-optimal minimal designs have been considered for a variety of mixture models, including Scheffé's linear, quadratic, and cubic models. Usually, these D-optimal designs are minimally supported since they have just as many design points as the number of parameters. Thus, they lack the degrees of freedom to perform the Lack of Fit tests. Also, the majority of the design points in D-optimal minimal designs are on the boundary: vertices, edges, or faces of the design simplex. Also a new strategy for adding multiple interior points for symmetric mixture models is proposed. We compare the proposed designs with Cornell (1986) two ten-point designs for the Lack of Fit test by simulations.

40 CFR Table 6 to Subpart G of... - Group 1 Storage Vessels at New Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Group 1 Storage Vessels at New Sources.... 63, Subpt. G, Table 6 Table 6 to Subpart G of Part 63—Group 1 Storage Vessels at New Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 38 ≤ capacity<151 ≥13.1 151 ≤ capacity ≥0.7 a Maximum...

40 CFR Table 6 to Subpart G of... - Group 1 Storage Vessels at New Sources

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Group 1 Storage Vessels at New Sources.... 63, Subpt. G, Table 6 Table 6 to Subpart G of Part 63—Group 1 Storage Vessels at New Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 38 ≤ capacity<151 ≥13.1 151 ≤ capacity ≥0.7 a Maximum...

40 CFR Table 6 to Subpart G of... - Group 1 Storage Vessels at New Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Group 1 Storage Vessels at New Sources.... 63, Subpt. G, Table 6 Table 6 to Subpart G of Part 63—Group 1 Storage Vessels at New Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 38 ≤ capacity<151 ≥13.1 151 ≤ capacity ≥0.7 a Maximum...

40 CFR Table 6 to Subpart G of... - Group 1 Storage Vessels at New Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Group 1 Storage Vessels at New Sources.... 63, Subpt. G, Table 6 Table 6 to Subpart G of Part 63—Group 1 Storage Vessels at New Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 38 ≤ capacity<151 ≥13.1 151 ≤ capacity ≥0.7 a Maximum...

40 CFR Table 6 to Subpart G of... - Group 1 Storage Vessels at New Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Group 1 Storage Vessels at New Sources.... 63, Subpt. G, Table 6 Table 6 to Subpart G of Part 63—Group 1 Storage Vessels at New Sources Vessel capacity(cubic meters) Vapor pressure a (kilopascals) 38 ≤capacity<151 ≥13.1 151 ≤capacity ≥0.7 a Maximum...

Volume Tables and Point-Sampling Factors for Shortleaf Pines in Plantation on Abandoned Fields in Tennessee, Alabama, and Georgia Highlands

Treesearch

Glendon W. Smalley; David R. Bower

1968-01-01

The tables and equations published here provide ways to estimate total and merchantable cubic-foot volumes, both inside and outside bark, of shortleaf pines (Pinus echinata Mill.) planted on abandoned fields in the Ridge and Valley, Cumberland Plateau, Eastern Highland Rim, and Western Highland Rim regions of Tennessee, Alabama, and Georgia (fig. 1). There already are...

Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, March-October 1990

USGS Publications Warehouse

Taylor, R. Lynn

1995-01-01

Depths and velocities, measured at sample points after benthic macroinvertebrate sampling, ranged from 0.03 to 0.30 meter and from 0.06 to 1.2 meters per second, respectively. Measurable stream discharge ranged from 0.01 to 0.27 cubic meter per second. During two of the sampling periods, no flow was at site 1.

Control theory and splines, applied to signature storage

NASA Technical Reports Server (NTRS)

Enqvist, Per

1994-01-01

In this report the problem we are going to study is the interpolation of a set of points in the plane with the use of control theory. We will discover how different systems generate different kinds of splines, cubic and exponential, and investigate the effect that the different systems have on the tracking problems. Actually we will see that the important parameters will be the two eigenvalues of the control matrix.

An analytical method to assess spruce beetle impacts on white spruce resources, Kenai Peninsula, Alaska.

Treesearch

Willem W.S. van Hees

1992-01-01

Forest inventory data collected in 1987 fTom sample plots established on the Kenai Peninsula were analyzed to provide point-in-time estimates of the trend and current status of a spruce beetle infestation. Ground plots were categorized by stage of infestation. Estimates of numbers of live and dead white spruce trees, cubic-foot volume in those trees, and areal extent...

Uhlenbeck-Ford model: Phase diagram and corresponding-states analysis

NASA Astrophysics Data System (ADS)

Paula Leite, Rodolfo; Santos-Flórez, Pedro Antonio; de Koning, Maurice

2017-09-01

Using molecular dynamics simulations and nonequilibrium thermodynamic-integration techniques we compute the Helmholtz free energies of the body-centered-cubic (bcc), face-centered-cubic (fcc), hexagonal close-packed, and fluid phases of the Uhlenbeck-Ford model (UFM) and use the results to construct its phase diagram. The pair interaction associated with the UFM is characterized by an ultrasoft, purely repulsive pair potential that diverges logarithmically at the origin. We find that the bcc and fcc are the only thermodynamically stable crystalline phases in the phase diagram. Furthermore, we report the existence of two reentrant transition sequences as a function of the number density, one featuring a fluid-bcc-fluid succession and another displaying a bcc-fcc-bcc sequence near the triple point. We find strong resemblances to the phase behavior of other soft, purely repulsive systems such as the Gaussian-core model (GCM), inverse-power-law, and Yukawa potentials. In particular, we find that the fcc-bcc-fluid triple point and the phase boundaries in its vicinity are in good agreement with the prediction supplied by a recently proposed corresponding-states principle [J. Chem. Phys. 134, 241101 (2011), 10.1063/1.3605659; Europhys. Lett. 100, 66004 (2012), 10.1209/0295-5075/100/66004]. The particularly strong resemblance between the behavior of the UFM and GCM models are also discussed.

Unexpectedly high piezoelectricity of Sm-doped lead zirconate titanate in the Curie point region.

PubMed

Seshadri, Shruti B; Nolan, Michelle M; Tutuncu, Goknur; Forrester, Jennifer S; Sapper, Eva; Esteves, Giovanni; Granzow, Torsten; Thomas, Pam A; Nino, Juan C; Rojac, Tadej; Jones, Jacob L

2018-03-07

Large piezoelectric coefficients in polycrystalline lead zirconate titanate (PZT) are traditionally achieved through compositional design using a combination of chemical substitution with a donor dopant and adjustment of the zirconium to titanium compositional ratio to meet the morphotropic phase boundary (MPB). In this work, a different route to large piezoelectricity is demonstrated. Results reveal unexpectedly high piezoelectric coefficients at elevated temperatures and compositions far from the MPB. At temperatures near the Curie point, doping with 2 at% Sm results in exceptionally large piezoelectric coefficients of up to 915 pm/V. This value is approximately twice those of other donor dopants (e.g., 477 pm/V for Nb and 435 pm/V for La). Structural changes during the phase transitions of Sm-doped PZT show a pseudo-cubic phase forming ≈50 °C below the Curie temperature. Possible origins of these effects are discussed and the high piezoelectricity is posited to be due to extrinsic effects. The enhancement of the mechanism at elevated temperatures is attributed to the coexistence of tetragonal and pseudo-cubic phases, which enables strain accommodation during electromechanical deformation and interphase boundary motion. This work provides insight into possible routes for designing high performance piezoelectrics which are alternatives to traditional methods relying on MPB compositions.

Enthalpy measurement of coal-derived liquids. Technical progress report, August-October 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kidnay, A.J.; Yesavage, V.F.

The correlational effort on the coal syncrudes and model compounds has been proceeding along two fronts. The first involves experimental work on a correlating factor for association in the liquids and the second involves an investigation of the modeling capabilities of cubic equations of state. The first area of investigation is the experimental measurement of a correlating factor for assocition in coal liquids. The procedure involves molecular weight measurement by freezing point depression. To facilitate these measurements, a simple Beckman freezing point depression apparatus is being currently modified to increase the accuracy, speed, and ease of measurement. The second areamore » of effort has involved establishing a set of cubic equations of state which can adequately model the enthalpy departures of quinoline and m-cresol. To this effort, a number of standard and association specific equations of state have been tested against a data base of previously measured enthalpy departures of m-cresol and quinoline. It has been found that these equations do quantitatively a poor job on m-cresol and quinoline. These problems are probably due to the highly polar nature of m-cresol and to a lesser extent quinoline, and to the poor quality of critical parameters for quinoline.« less

A net volume equation for Indiana.

Treesearch

W. Brad Smith; Carol A. Weist

1982-01-01

Describes a Weibull-type volume equation for Indiana developed as part of the ongoing Resource Evaluation research in the Central States. Equation coefficients are presented by species groupings for both cubic foot and board foot volumes for three tree class categories.

Assessment of the SMAP Passive Soil Moisture Product

NASA Technical Reports Server (NTRS)

Chan, Steven K.; Bindlish, Rajat; O'Neill, Peggy E.; Njoku, Eni; Jackson, Tom; Colliander, Andreas; Chen, Fan; Burgin, Mariko; Dunbar, Scott; Piepmeier, Jeffrey;

Floods of September 15-16, 1992, in the Thompson, Weldon, and Chariton River basins, south-central Iowa

USGS Publications Warehouse

Eash, D.A.; Koppensteiner, B.A.

1997-01-01

Water-surface-elevation profiles and peak discharges for the floods of September 15-16, 1992, in the Thompson, Weldon, and Chariton River Basins, south-central Iowa, are presented in this report. The profiles illustrate the 1992 floods along the Thompson, Weldon, Chariton, and South Fork Chariton Rivers and along Elk Creek in the south-central Iowa counties of Adair, Clarke, Decatur, Lucas, Madison, Ringgold, Union, and Wayne. Water-surface-elevation profiles for the floods of July 4, 1981, along the Chariton River in Lucas County and along the South Fork Chariton River in Wayne County also are included in the report for comparative purposes. The September 15-16, 1992, floods are the largest known peak discharges at gaging stations Thompson River at Davis City (station number 06898000) 57,000 cubic feet per second, Weldon River near Leon (station number 06898400) 76,200 cubic feet per second, Chariton River near Chariton (station number 06903400) 37,700 cubic feet per second, and South Fork Chariton River near Promise City (station number 06903700) 70,600 cubic feet per second. The peak discharges were, respectively, 1.7, 2.6, 1.4, and 2.1 times larger than calculated 100-year recurrence-interval discharges. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Thompson, Weldon, and Chariton River Basins using flood information collected through 1995. Information on temporary bench marks and reference points established in the Thompson and Weldon River Basins during 1994-95, and in the Chariton River Basin during 1983-84 and 1994-95, also is included in the report. A flood history summarizes rainfall conditions and damages for floods that occurred during 1947, 1959, 1981, 1992, and 1993.

Phonons and superconductivity in fcc and dhcp lanthanum

NASA Astrophysics Data System (ADS)

Baǧcı, S.; Tütüncü, H. M.; Duman, S.; Srivastava, G. P.

2010-04-01

We have investigated the structural and electronic properties of lanthanum in the face-centered-cubic (fcc) and double hexagonal-close-packed (dhcp) phases using a generalized gradient approximation of the density functional theory and the ab initio pseudopotential method. It is found that double hexagonal-close-packed is the more stable phase for lanthanum. Differences in the density of states at the Fermi level between these two phases are pointed out and discussed in detail. Using the calculated lattice constant and electronic band structure for both phases, a linear response approach based on the density functional theory has been applied to study phonon modes, polarization characteristics of phonon modes, and electron-phonon interaction. Our phonon results show a softening behavior of the transverse acoustic branch along the Γ-L direction and the Γ-M direction for face-centered-cubic and double hexagonal-close-packed phases, respectively. Thus, the transverse-phonon linewidth shows a maximum at the zone boundary M(L) for the double hexagonal-close-packed phase (face-centered-cubic phase), where the transverse-phonon branch exhibits a dip. The electron-phonon coupling parameter λ is found to be 0.97 (1.06) for the double hexagonal-close-packed phase (face-centered-cubic phase), and the superconducting critical temperature is estimated to be 4.87 (dhcp) and 5.88 K (fcc), in good agreement with experimental values of around 5.0 (dhcp) and 6.0 K (fcc). A few superconducting parameters for the double hexagonal-close-packed phase have been calculated and compared with available theoretical and experimental results. Furthermore, the calculated superconducting parameters for both phases are compared between each other in detail.

Relationships among dietary fiber components and the digestibility of energy, dietary fiber, and amino acids and energy content of nine corn coproducts fed to growing pigs.

PubMed

Gutierrez, N A; Serão, N V L; Kerr, B J; Zijlstra, R T; Patience, J F

2014-10-01

An experiment was conducted to determine a best fitting dietary fiber (DF) component to estimate the effect of DF concentration on the digestibility of energy, DF, and AA and energy value of 9 corn coproducts: corn bran (37.0% total nonstarch polysaccharides [NSP]); corn bran with solubles (17.1% NSP); cooked corn distillers dried grains with solubles (DDGS; 20.4% NSP); reduced oil DDGS (25.0% NSP); uncooked DDGS (22.0% NSP); high protein distillers dried grains (21.9% NSP); dehulled, degermed corn (1.1% NSP); corn germ meal (44.4% NSP); and corn gluten meal (4.9% NSP). A total of 20 growing pigs (initial BW: 25.9 ± 2.5 kg) were fitted with a T-cannula in the distal ileum and allotted to 10 dietary treatment groups in a 4-period incomplete block design with 8 observations per treatment. Treatments included a corn-soybean meal-based basal diet and 9 diets obtained by mixing 70% of the basal diet with 30% of the test ingredient. In tested ingredients, 11 DF components were determined: 1) ADF, 2) NDF, 3) total dietary fiber, 4) hemicellulose, 5) total NSP, 6) NSP arabinose, 7) NSP xylose, 8) NSP mannose, 9) NSP glucose, 10) NSP galactose, and 11) arabinoxylan. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of GE, DM, and NDF and the AID of AA of ingredients were measured. A single best fitting DF component was assessed and ranked for each trait, showing that arabinoxylan concentration best explained variance in AID of GE (R(2) = 0.65; cubic, P < 0.01) and DM (R(2) = 0.67; cubic, P < 0.01). The NSP xylose residue best explained variance in ATTD of GE (R(2) = 0.80; cubic, P < 0.01), DM (R(2) = 0.78; cubic, P < 0.01), and NDF (R(2) = 0.63; cubic, P < 0.01); AID of Met (R(2) = 0.40; cubic, P = 0.02), Met + Cys (R(2) = 0.44; cubic, P = 0.04), and Trp (R(2) = 0.11; cubic, P = 0.04); and DE (R(2) = 0.66; linear, P = 0.02) and ME (R(2) = 0.71; cubic, P = 0.01) values. The AID of Lys was not predictable (P > 0.05) from the DF concentration. In conclusion, the arabinoxylan and NSP xylose residue were the DF components that best explained variation due to DF concentration and, with the exception of AID of Lys, can be used to predict the digestibility of energy and DF and the DE and ME values in corn coproducts.

Datum Feature Extraction and Deformation Analysis Method Based on Normal Vector of Point Cloud

NASA Astrophysics Data System (ADS)

Sun, W.; Wang, J.; Jin, F.; Liang, Z.; Yang, Y.

2018-04-01

In order to solve the problem lacking applicable analysis method in the application of three-dimensional laser scanning technology to the field of deformation monitoring, an efficient method extracting datum feature and analysing deformation based on normal vector of point cloud was proposed. Firstly, the kd-tree is used to establish the topological relation. Datum points are detected by tracking the normal vector of point cloud determined by the normal vector of local planar. Then, the cubic B-spline curve fitting is performed on the datum points. Finally, datum elevation and the inclination angle of the radial point are calculated according to the fitted curve and then the deformation information was analyzed. The proposed approach was verified on real large-scale tank data set captured with terrestrial laser scanner in a chemical plant. The results show that the method could obtain the entire information of the monitor object quickly and comprehensively, and reflect accurately the datum feature deformation.

Single point diamond crushing of glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, J.B.; Carter, D.L.; Clouser, R.W.

1984-05-23

Single point diamond crushing of glass was originally developed by Dr. R.E. Reason of Taylor and Hobson in England 34 years ago as a means of shaping glass aspheres prior to polishing. It has recently been tried at LLNL. A surface finish of 50 microinches peak-to-valley with occasional deeper pits has been achieved on Zerodur and BK-7 glass. A depth of cut of 0.008 inch or more can be taken at a surface speed of 900 feet per minute. Tool wear is on the order of 10 microinches after removal of one cubic inch of Zerodur. The tool's cost ismore » $5.45 each.« less

40 CFR 60.3 - Units and abbreviations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... m—meter m3—cubic meter mg—milligram—10 −3 gram mm—millimeter—10 −3 meter Mg—megagram—106 gram mol—mole N—newton ng—nanogram—10 −9 gram nm—nanometer—10 −9 meter Pa—pascal s—second V—volt W—watt Ω—ohm µg...—calorie cfm—cubic feet per minute cu ft—cubic feet dcf—dry cubic feet dcm—dry cubic meter dscf—dry cubic...

A net volume equation for Michigan's Upper and Lower Peninsulas.

Treesearch

Gerhard K. Raile; W. Brad Smith; Carol A. Weist

1982-01-01

Describes a volume equation for Michigan's Upper and Lower Peninsulas developed as part of the 1981 Michigan Forest Inventory. Equation coefficients are presented by species groupings for both cubic-foot and board-foot volumes for three tree categories.

Neutron Diffraction Study Oxygen Dissolution Alpha(sub 2)-Ti3Al

NASA Technical Reports Server (NTRS)

Jones, Camille Y.; Luecke, William E.; Copland, Evan

2005-01-01

Rietveld refinements of neutron powder diffraction data on alpha(sub 2)-Ti3Al have been performed to determine the crystal structure as a function of interstitial oxygen (O) concentration for three alloys with a Ti/Al ratio of approximately equal to 2.34 and O concentrations of 0.25%, 3.99% and 7.71%. The structures of the allows are hexagonal in space group P6(sub 3)/mmc where Ti and Al atoms populate unique sites with excess Al at the Ti site and O atoms occupy octahedral interstitial sites surrounded by six Ti sites. The length of the c-axis was found to increase linearly as the O occupancy of the interstitial sites increased; this lattice lengthening effect was much less pronounced along the alpha axis. Correspondingly, the increases in the lengths of Ti-Al and Ti-Ti bonds with a major component of their direction parallel to the c-axis were roughly an order of magnitude greater than the increases in the lengths of Ti-al and Ti-Ti bonds more closely aligned with the alpha-axis. Densities calculated form the lattice parameters and occupancy factors fall in the range (4.118 plus or minus 0.004) grams per cubic centimeter to (4.194 plus or minus 0.004) grams per cubic centimeter, and exhibit a nearly linear increase with oxygen concentration. Measured densities of (4.113 plus or minus 0.001) grams per cubic centimeter, (4.146 plus or minus 0.009) grams per cubic centimeter, and (4.191 plus or minus 0.002) grams per cubic centimeter for these alloys agree with the results of the refinements.

Mechano-chemical synthesis K2MF6 (M = Mn, Ni) by cation-exchange reaction at room temperature

NASA Astrophysics Data System (ADS)

Rawat, Pooja; Nagarajan, Rajamani

2018-02-01

In order to establish the power of mechanochemistry to produce industrially important phosphors, synthesis of K2MnF6 has been attempted by the successive grinding reactions of manganese (II) acetate with ammonium fluoride and potassium fluoride. The progress of reaction was followed by ex-situ characterization after periodic intervals of time. Cubic symmetry of K2MnF6 was evident from its powder X-ray diffraction pattern which was refined successfully in cubic space group (Fm-3m) with a = 8.4658 (20) Å. Stretching and bending vibration modes of MnF62- octahedral units appeared at 740 and 482 cm-1 in the fourier transformed infrared spectrum. Bands at 405 and 652 cm-1 appeared in the Raman spectrum and they were finger-print positions of cubic K2MnF6. Other than the ligand to metal charge transfer transition at 242 nm, transitions from 4A2g to 4T1g, 4T2g and 2T2g of Mn4+-ion appeared at 352, 429, 474 and 569 nm in the UV-visible diffuse reflectance spectrum of the sample. Red emission due to Mn4+ was observed in the photoluminescence spectrum with a decay time of 0.22 ms. Following the success in forming cubic K2MnF6, this approach has been extended to synthesize cubic K2NiF6 at room temperature. All these results confirmed the susceptibility of acetate salts of transition metals belonging to first-row of the periodic table to facile fluorination at room temperature aided by mechanical forces.

Precision mass measurements of magnesium isotopes and implications for the validity of the isobaric mass multiplet equation

DOE PAGES

Brodeur, M.; Kwiatkowski, A. A.; Drozdowski, O. M.; ...

2017-09-18

If the mass excess of neutron-deficient nuclei and their neutron-rich mirror partners are both known, it can be shown that deviations of the isobaric mass multiplet equation (IMME) in the form of a cubic term can be probed. Such a cubic term was probed by using the atomic mass of neutron-rich magnesium isotopes measured using the TITAN Penning trap and the recently measured proton-separation energies of 29Cl and 30Ar. The atomic mass of 27Mg was found to be within 1.6σ of the value stated in the Atomic Mass Evaluation. The atomic masses of 28,29Mg were measured to be both withinmore » 1σ, while being 7 and 33 times more precise, respectively. Using the 29Mg mass excess and previous measurements of 29Cl, we uncovered a cubic coefficient of d = 28(7)keV, which is the largest known cubic coefficient of the IMME. This departure, however, could also be caused by experimental data with unknown systematic errors. Hence there is a need to confirm the mass excess of 28S and the one-neutron separation energy of 29Cl, which have both come from a single measurement. Lastly, our results were compared with ab initio calculations from the valence-space in-medium similarity renormalization group, resulting in a good agreement.« less

Precision mass measurements of magnesium isotopes and implications for the validity of the isobaric mass multiplet equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodeur, M.; Kwiatkowski, A. A.; Drozdowski, O. M.

If the mass excess of neutron-deficient nuclei and their neutron-rich mirror partners are both known, it can be shown that deviations of the isobaric mass multiplet equation (IMME) in the form of a cubic term can be probed. Such a cubic term was probed by using the atomic mass of neutron-rich magnesium isotopes measured using the TITAN Penning trap and the recently measured proton-separation energies of 29Cl and 30Ar. The atomic mass of 27Mg was found to be within 1.6σ of the value stated in the Atomic Mass Evaluation. The atomic masses of 28,29Mg were measured to be both withinmore » 1σ, while being 7 and 33 times more precise, respectively. Using the 29Mg mass excess and previous measurements of 29Cl, we uncovered a cubic coefficient of d = 28(7)keV, which is the largest known cubic coefficient of the IMME. This departure, however, could also be caused by experimental data with unknown systematic errors. Hence there is a need to confirm the mass excess of 28S and the one-neutron separation energy of 29Cl, which have both come from a single measurement. Lastly, our results were compared with ab initio calculations from the valence-space in-medium similarity renormalization group, resulting in a good agreement.« less

Application of the algebraic RNG model for transition simulation. [renormalization group theory

NASA Technical Reports Server (NTRS)

Lund, Thomas S.

1990-01-01

The algebraic form of the RNG model of Yakhot and Orszag (1986) is investigated as a transition model for the Reynolds averaged boundary layer equations. It is found that the cubic equation for the eddy viscosity contains both a jump discontinuity and one spurious root. A yet unpublished transformation to a quartic equation is shown to remove the numerical difficulties associated with the discontinuity, but only at the expense of merging both the physical and spurious root of the cubic. Jumps between the branches of the resulting multiple-valued solution are found to lead to oscillations in flat plate transition calculations. Aside from the oscillations, the transition behavior is qualitatively correct.

Instantaneous nonlinear assessment of complex cardiovascular dynamics by Laguerre-Volterra point process models.

PubMed

Valenza, Gaetano; Citi, Luca; Barbieri, Riccardo

2013-01-01

We report an exemplary study of instantaneous assessment of cardiovascular dynamics performed using point-process nonlinear models based on Laguerre expansion of the linear and nonlinear Wiener-Volterra kernels. As quantifiers, instantaneous measures such as high order spectral features and Lyapunov exponents can be estimated from a quadratic and cubic autoregressive formulation of the model first order moment, respectively. Here, these measures are evaluated on heartbeat series coming from 16 healthy subjects and 14 patients with Congestive Hearth Failure (CHF). Data were gathered from the on-line repository PhysioBank, which has been taken as landmark for testing nonlinear indices. Results show that the proposed nonlinear Laguerre-Volterra point-process methods are able to track the nonlinear and complex cardiovascular dynamics, distinguishing significantly between CHF and healthy heartbeat series.

Magneto-optical study of holmium iron garnet Ho3Fe5O12

NASA Astrophysics Data System (ADS)

Kalashnikova, A. M.; Pavlov, V. V.; Kimel, A. V.; Kirilyuk, A.; Rasing, Th.; Pisarev, R. V.

2012-09-01

Bulk holmium iron garnet Ho3Fe5O12 is a cubic ferrimagnet with Curie temperature TC = 567 K and magnetization compensation point in the range 130-140 K. The magneto-optical data are presented for a holmium iron garnet Ho3Fe5O12 film, ˜10 μm thick, epitaxially grown on a (111)-type gadolinium-gallium garnet Gd3Ga5O12 substrate. A specific feature of this structure is that the parameters of the bulk material, from which the film was grown, closely match the substrate ones. The temperature and field dependences of Faraday rotation as well as the temperature dependence of the domain structure in zero field were investigated. The compensation point of the structure was found to be Tcomp = 127 K. It was shown that the temperature dependence of the characteristic size of domain structure diverges at this point. Based on the obtained results we established that the magnetic anisotropy of the material is determined by both uniaxial and cubic contributions, each characterized by different temperature dependence. A complex shape of hysteresis loops and sharp changes of the domain pattern with temperature indicate the presence of collinear-noncollinear phase transitions. Study of the optical second harmonic generation was carried out using 100 fs laser pulses with central photon energy E = 1.55 eV. The electric dipole contribution (both crystallographic and magnetic) to the second harmonic generation was observed with high reliability despite a small mismatch of the film and substrate parameters.

Nonlinear instability of half-solitons on star graphs

NASA Astrophysics Data System (ADS)

Kairzhan, Adilbek; Pelinovsky, Dmitry E.

2018-06-01

We consider a half-soliton stationary state of the nonlinear Schrödinger equation with the power nonlinearity on a star graph consisting of N edges and a single vertex. For the subcritical power nonlinearity, the half-soliton state is a degenerate critical point of the action functional under the mass constraint such that the second variation is nonnegative. By using normal forms, we prove that the degenerate critical point is a saddle point, for which the small perturbations to the half-soliton state grow slowly in time resulting in the nonlinear instability of the half-soliton state. The result holds for any N ≥ 3 and arbitrary subcritical power nonlinearity. It gives a precise dynamical characterization of the previous result of Adami et al. (2012) [2], where the half-soliton state was shown to be a saddle point of the action functional under the mass constraint for N = 3 and for cubic nonlinearity.

Friction surfaced Stellite6 coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid, E-mail: khalidrafi@gmail.com

2012-08-15

Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material formore » friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.« less

Structure of polarization singularities of a light beam at triple frequency generated in isotropic medium by singularly polarized beam.

PubMed

Grigoriev, K S; Ryzhikov, P S; Cherepetskaya, E B; Makarov, V A

2017-10-16

The components of electric field of the third harmonic beam, generated in isotropic medium with cubic nonlinearity by a monochromatic light beam carrying polarization singularity of an arbitrary type, are found analytically. The relation between C-points characteristics in the fundamental and signal beams are determined, as well as the impact of the phase mismatch on the shape of the C-lines.

Theory of freezing in simple systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cerjan, C.; Bagchi, B.

The transition parameters for the freezing of two one-component liquids into crystalline solids are evaluated by two theoretical approaches. The first system considered is liquid sodium which crystallizes into a body-centered-cubic (bcc) lattice; the second system is the freezing of adhesive hard spheres into a face-centered-cubic (fcc) lattice. Two related theoretical techniques are used in this evaluation: One is based upon a recently developed bifurcation analysis; the other is based upon the theory of freezing developed by Ramakrishnan and Yussouff. For liquid sodium, where experimental information is available, the predictions of the two theories agree well with experiment and eachmore » other. The adhesive-hard-sphere system, which displays a triple point and can be used to fit some liquids accurately, shows a temperature dependence of the freezing parameters which is similar to Lennard-Jones systems. At very low temperature, the fractional density change on freezing shows a dramatic increase as a function of temperature indicating the importance of all the contributions due to the triplet direction correlation function. Also, we consider the freezing of a one-component liquid into a simple-cubic (sc) lattice by bifurcation analysis and show that this transition is highly unfavorable, independent of interatomic potential choice. The bifurcation diagrams for the three lattices considered are compared and found to be strikingly different. Finally, a new stability analysis of the bifurcation diagrams is presented.« less

Phase degradation in B xGa 1–xN films grown at low temperature by metalorganic vapor phase epitaxy

DOE PAGES

Gunning, Brendan P.; Moseley, Michael W.; Koleske, Daniel D.; ...

2016-11-01

Using metalorganic vapor phase epitaxy, a comprehensive study of B xGa 1-xN growth on GaN and AlN templates is described. BGaN growth at high-temperature and high-pressure results in rough surfaces and poor boron incorporation efficiency, while growth at low-temperature and low-pressure (750–900 °C and 20 Torr) using nitrogen carrier gas results in improved surface morphology and boron incorporation up to ~7.4% as determined by nuclear reaction analysis. However, further structural analysis by transmission electron microscopy and x-ray pole figures points to severe degradation of the high boron composition films, into a twinned cubic structure with a high density of stackingmore » faults and little or no room temperature photoluminescence emission. Films with <1% triethylboron (TEB) flow show more intense, narrower x-ray diffraction peaks, near-band-edge photoluminescence emission at ~362 nm, and primarily wurtzite-phase structure in the x-ray pole figures. For films with >1% TEB flow, the crystal structure becomes dominated by the cubic phase. As a result, only when the TEB flow is zero (pure GaN), does the cubic phase entirely disappear from the x-ray pole figure, suggesting that under these growth conditions even very low boron compositions lead to mixed crystalline phases.« less

Phase degradation in B xGa 1–xN films grown at low temperature by metalorganic vapor phase epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunning, Brendan P.; Moseley, Michael W.; Koleske, Daniel D.

Using metalorganic vapor phase epitaxy, a comprehensive study of B xGa 1-xN growth on GaN and AlN templates is described. BGaN growth at high-temperature and high-pressure results in rough surfaces and poor boron incorporation efficiency, while growth at low-temperature and low-pressure (750–900 °C and 20 Torr) using nitrogen carrier gas results in improved surface morphology and boron incorporation up to ~7.4% as determined by nuclear reaction analysis. However, further structural analysis by transmission electron microscopy and x-ray pole figures points to severe degradation of the high boron composition films, into a twinned cubic structure with a high density of stackingmore » faults and little or no room temperature photoluminescence emission. Films with <1% triethylboron (TEB) flow show more intense, narrower x-ray diffraction peaks, near-band-edge photoluminescence emission at ~362 nm, and primarily wurtzite-phase structure in the x-ray pole figures. For films with >1% TEB flow, the crystal structure becomes dominated by the cubic phase. As a result, only when the TEB flow is zero (pure GaN), does the cubic phase entirely disappear from the x-ray pole figure, suggesting that under these growth conditions even very low boron compositions lead to mixed crystalline phases.« less

Far-infrared transmission in GaN, AlN, and AlGaN thin films grown by molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibanez, J.; Hernandez, S.; Alarcon-Llado, E.

2008-08-01

We present a far-infrared transmission study on group-III nitride thin films. Cubic GaN and AlN layers and c-oriented wurtzite GaN, AlN, and Al{sub x}Ga{sub 1-x}N (x<0.3) layers were grown by molecular beam epitaxy on GaAs and Si(111) substrates, respectively. The Berreman effect allows us to observe simultaneously the transverse optic and the longitudinal optic phonons of both the cubic and the hexagonal films as transmission minima in the infrared spectra acquired with obliquely incident radiation. We discuss our results in terms of the relevant electromagnetic theory of infrared transmission in cubic and wurtzite thin films. We compare the infrared resultsmore » with visible Raman-scattering measurements. In the case of films with low scattering volumes and/or low Raman efficiencies and also when the Raman signal of the substrate material obscures the weaker peaks from the nitride films, we find that the Berreman technique is particularly useful to complement Raman spectroscopy.« less

Coating of Carbon Fiber with Polyhedral Oligomeric Silsesquioxane (POSS) to Enhance Mechanical Properties and Durability of Carbon/Vinyl Ester Composites

PubMed Central

Mahfuz, Hassan; Powell, Felicia; Granata, Richard; Hosur, Mahesh; Khan, Mujib

2011-01-01

Our continuing quest to improve the performance of polymer composites under moist and saltwater environments has gained momentum in recent years with the reinforcement of inorganic nanoparticles into the polymer. The key to mitigate degradation of composites under such environments is to maintain the integrity of the fiber/matrix (F/M) interface. In this study, the F/M interface of carbon/vinyl ester composites has been modified by coating the carbon fiber with polyhedral oligomeric silsesquioxane (POSS). POSS is a nanostructured inorganic-organic hybrid particle with a cubic structure having silicon atoms at the core and linked to oxygen atoms. The advantage of using POSS is that the silicon atoms can be linked to a substituent that can be almost any chemical group known in organic chemistry. Cubic silica cores are ‘hard particles’ and are about 0.53 nm in diameter. The peripheral organic unit is a sphere of about 1–3 nm in diameter. Further, cubic structure of POSS remains intact during the polymerization process and therefore with appropriate functional groups, if installed on the fiber surface, would provide a stable and strong F/M interface. Two POSS systems with two different functional groups; namely, octaisobutyl and trisilanolphenyl have been investigated. A set of chemical and mechanical procedures has been developed to coat carbon fibers with POSS, and to fabricate layered composites with vinyl ester resin. Interlaminar shear and low velocity impact tests have indicated around 17–38% improvement in mechanical properties with respect to control samples made without the POSS coating. Saltwater and hygrothermal tests at various environmental conditions have revealed that coating with POSS reduces water absorption by 20–30% and retains the composite properties. PMID:28824160

Electronic properties and structural phase transition in A4 [M4O4] (A=Li, Na, K and Rb; M=Ag and Cu): A first principles study

NASA Astrophysics Data System (ADS)

Umamaheswari, R.; Yogeswari, M.; Kalpana, G.

2013-02-01

Self-consistent scalar relativistic band structure calculations for AMO (A=Li, Na, K and Rb; M=Ag and Cu) compounds have been performed using the tight-binding linear muffin-tin orbital (TB-LMTO) method within the local density approximation (LDA). At ambient conditions, these compounds are found to crystallize in tetragonal KAgO-type structure with two different space group I-4m2 and I4/mmm. Nowadays, hypothetical structures are being considered to look for new functional materials. AMO compounds have stoichiometry similar to eight-electron half-Heusler materials of type I-I-VI which crystallizes in cubic (C1b) MgAgAs-type structure with space group F-43m. For all these compounds, by interchanging the positions of atoms in the hypothetical cubic structure, three phases (α, β and γ) are formed. The energy-volume relation for these compounds in tetragonal KAgO-type structure and cubic α, β and γ phases of related structure have been obtained. Under ambient conditions these compounds are more stable in tetragonal KAgO-type (I4/mmm) structure. The total energies calculated within the atomic sphere approximation (ASA) were used to determine the ground state properties such as equilibrium lattice parameters, c/a ratio, bulk modulus, cohesive energy and are compared with the available experimental results. The results of the electronic band structure calculations at ambient condition show that LiCuO and NaMO are indirect band gap semiconductors whereas KMO and RbMO are direct band gap semiconductors. At high pressure the band gap decreases and the phenomenon of band overlap metallization occur. Also these compounds undergo structural phase transition from tetragonal I-4m2 phase to cubic α-phase and transition pressures were calculated.

Cubic liquid crystalline nanoparticles: optimization and evaluation for ocular delivery of tropicamide.

PubMed

Verma, Purnima; Ahuja, Munish

2016-10-01

The purpose of this study was to investigate the potential of cubic liquid crystalline nanoparticles for ocular delivery of tropicamide. Ultrasound-assisted fragmentation of cubic liquid crystalline bulk phases resulted in cubic liquid crystalline nanoparticles employing Pluronic F127 as dispersant. The effects of process variables such as sonication time, sonication amplitude, sonication depth, and pre-mixing time on particle size and polydispersity index was investigated using central composite design. The morphology of tropicamide-loaded nanoparticles was found to be nearly cubical in shape by transmission electron microscopy observation. Further, small angle X-ray scattering experiment confirmed the presence of D and P phase cubic structures in coexistence. The optimized tropicamide-loaded cubic nanoparticles showed in vitro corneal permeation of tropicamide across isolated porcine cornea comparable to its commercial preparation, Tropicacyl®. Ocular tolerance was evaluated by Hen's egg-chorioallantoic membrane test and histological studies. The results of in vivo mydriatic response study demonstrated a remarkably higher area under mydriatic response curve (AUC 0→1440 min ) values of cubic nanoparticles over Tropicacyl® indicating better therapeutic value of cubic nanoparticles. Furthermore, tropicamide-loaded cubic nanoparticles exhibited prolonged mydriatic effect on rabbits as compared to commercial conventional aqueous ophthalmic solution.

Towards Development of Innovative Bio-Inspired Materials by Analyzing the Hydrodynamic Properties of Polyondon Spathula (Paddlefish) Rostrum

DTIC Science & Technology

2013-09-01

Factors Multiply By To Obtain cubic inches 1.6387064 E -05 cubic meters inches 0.0254 meters pounds (force) 4.448222 newtons pounds (force) per...0.45359237 kilograms pounds (mass) per cubic foot 16.01846 kilograms per cubic meter pounds (mass) per cubic inch 2.757990 E +04 kilograms per cubic...14.59390 kilograms square inches 6.4516 E -04 square meters ERDC/ITL TR-13-4 1 1 Introduction 1.1 Bio–inspiration Nature has evolved from a

Thermoelectric properties of p-type cubic and rhombohedral GeTe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing, Guangzong; Sun, Jifeng; Li, Yuwei

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

Thermoelectric properties of p-type cubic and rhombohedral GeTe

DOE PAGES

Xing, Guangzong; Sun, Jifeng; Li, Yuwei; ...

2018-05-21

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

Y-TZP zirconia regeneration firing: Microstructural and crystallographic changes after grinding.

PubMed

Ryan, Daniel Patrick Obelenis; Fais, Laiza Maria Grassi; Antonio, Selma Gutierrez; Hatanaka, Gabriel Rodrigues; Candido, Lucas Miguel; Pinelli, Ligia Antunes Pereira

2017-07-26

This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (Lava TM and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was conducted using a diamond bur and annealing at 1,000°C. The microstructure was analyzed by SEM and the crystalline phases by X-ray diffraction (XRD). XRD showed that pre-sintered specimens contained tetragonal and monoclinic phases, while groups C and R showed tetragonal, cubic and monoclinic phases. After grinding, the cubic phase was eliminated in all groups. Annealing (DGR and WGR) resulted in only tetragonal phase. SEM showed semi-circular cracks after grinding and homogenization of particles after annealing. After grinding, surfaces show tetragonal and monoclinic phases and R can be assumed to be necessary prior to porcelain layering when grinding is performed.

Aqueous solution epitaxy of CdS layers on CuInSe 2

NASA Astrophysics Data System (ADS)

Furlong, M. J.; Froment, M.; Bernard, M. C.; Cortès, R.; Tiwari, A. N.; Krejci, M.; Zogg, H.; Lincot, D.

1998-09-01

Epitaxial CdS thin films have been deposited from an aqueous ammonia solution containing cadmium ions and thiourea as precursors on single crystalline CuInSe 2 films prepared by MBE on Si(1 1 1) and GaAs(1 0 0) substrates. The structure and quality of the films were investigated by RHEED, glancing angle XRD and HRTEM in cross-section. The films are cubic on (1 0 0) substrates, and mixed cubic and hexagonal on (1 1 1) substrates due to the presence of stacking faults parallel to the substrate. The growth is under surface kinetic control with an activation energy of 85 kJ mol -1. Epitaxy improves with increasing temperature and an epitaxial transition temperature at approx. 60°C is demonstrated in the selected experimental conditions. The epitaxy is very sensitive to the preparation of the surface. Beneficial effects of in situ or ex situ chemical etching are found. Similarities between aqueous solution and vapor-phase chemical depositions are pointed out.

Intricacies of cosmological bounce in polynomial metric f(R) gravity for flat FLRW spacetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharya, Kaushik; Chakrabarty, Saikat, E-mail: kaushikb@iitk.ac.in, E-mail: snilch@iitk.ac.in

2016-02-01

In this paper we present the techniques for computing cosmological bounces in polynomial f(R) theories, whose order is more than two, for spatially flat FLRW spacetime. In these cases the conformally connected Einstein frame shows up multiple scalar potentials predicting various possibilities of cosmological evolution in the Jordan frame where the f(R) theory lives. We present a reasonable way in which one can associate the various possible potentials in the Einstein frame, for cubic f(R) gravity, to the cosmological development in the Jordan frame. The issue concerning the energy conditions in f(R) theories is presented. We also point out themore » very important relationships between the conformal transformations connecting the Jordan frame and the Einstein frame and the various instabilities of f(R) theory. All the calculations are done for cubic f(R) gravity but we hope the results are sufficiently general for higher order polynomial gravity.« less

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

DOE PAGES

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett; ...

2016-08-22

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within themore » crystal lattice is confirmed by time-resolved visible absorption spectroscopy. Furthermore, this study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.« less

Single-Channel Seismic-Reflection Profiles Collected Over the U.S. Atlantic Continental Shelf, Slope, and Rise East of Cape Hatteras

USGS Publications Warehouse

Bailey, Norman G.; Grow, John A.

1980-01-01

During late October 1977, water discharge from Minidoka Dam into the Milner reach of the Snake River was less than 22 cubic meters per second, compared to normal flows for that time of year of about 42 cubic meters per second or more. To determine if impaired water-quality conditions existed, samples were collected at several sites above and below major point-source waste discharges near Burley, Idaho. Data collected for this study indicate some water-quality impairment within the study reach. At site 15 near Milner Dam, dissolved oxygen was below the 90 percent saturation standard prescribed by the Idaho water-quality standards. The total coliform and fecal coliform standards were exceeded at about one-third of the sites sampled on the main stem of the Snake River. Un-ionized ammonia concentration exceeded U.S. Environmental Protection Agency water-quality criteria at one site near Burley. Concentrations of trace metals, insecticides, and herbicides were all low; none exceeded existing criteria. (USGS)

Ferroelectric, elastic, piezoelectric, and dielectric properties of Ba(Ti0.7Zr0.3)O3-x(Ba0.82Ca0.18)TiO3 Pb-free ceramics

NASA Astrophysics Data System (ADS)

Yuan, Ruihao; Xue, Deqing; Zhou, Yumei; Ding, Xiangdong; Sun, Jun; Xue, Dezhen

2017-07-01

We designed and synthesized a pseudo-binary Pb-free system, Ba(Ti0.7Zr0.3)O3-x(Ba0.82Ca0.18)TiO3, by combining a rhombohedral end (with only cubic to rhombohedral ferroelectric phase transition) and a tetragonal end (with only cubic to tetragonal ferroelectric phase transition). The established composition-temperature phase diagram is characterized by a tricritical point type morphotropic phase boundary (MPB), and the MPB composition has better ferroelectric, piezoelectric, and dielectric properties than the compositions deviating from MPB. Moreover, a full set of material constants (including elastic stiffness constants, elastic compliance constants, piezoelectric constants, dielectric constants, and electromechanical coupling factors) of the MPB composition are determined using a resonance method. The good piezoelectric performance of the MPB composition can be ascribed to the high dielectric constants, elastic softening, and large electromechanical coupling factor.

Atomic mean-square displacement of a solid: A Green's-function approach

NASA Astrophysics Data System (ADS)

Shukla, R. C.; Hübschle, Hermann

1989-07-01

We have presented a Green's-function method of calculating the atomic mean-square displacement (MSD) of a solid. The method effectively sums a class of all anharmonic contributions to the MSD. From the point of view of perturbation theory (PT) our expression for MSD includes the lowest-order (λ2) PT contributions (cubic and quartic) with correct numerical coefficients. The numerical results obtained by this method in the high-temperature limit for a fcc nearest-neighbor Lennard-Jones-solid model are in excellent agreement with the Monte Carlo (MC) method for the same model over the entire temperature range of the solid. Highly accurate results for the order-λ2 PT contributions to MSD are obtained by eliminating the uncertainty in the convergence of the cubic contributions in the earlier work of Heiser, Shukla, and Cowly and they are now in much better agreement with the MC results but still inferior to the Green's-function method at the highest temperature.

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within themore » crystal lattice is confirmed by time-resolved visible absorption spectroscopy. Furthermore, this study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.« less

Traveltimes of flood waves on the New River between Hinton and Hawks Nest, West Virginia

USGS Publications Warehouse

Appel, David H.

1983-01-01

The New River Gorge National River's [a 51-mile segment of the New River between Hinton and Fayette (an abandoned community), W. Va. main attraction is a combination of scenic wilderness, fishing, cultural resources, and whitewater boating. However, recreational quality, safety, and use of the river depends in part upon the amount and fluctuations in streamflow, manmade and natural. During 1981 and 1982, the U.S. Geological Survey found that the flood wave travels at an average speed of 6.8 miles per hour when streamflow is 15,000 cubic feet per second and 3.5 miles per hour when streamflow is 2,200 cubic feet per second. Curves have been developed to estimate traveltimes between any two points within the National River jurisdiction. The gaging station at Thurmond, installed as part of this study, can be called by telephone, (304) 465-0493, to determine river stage. The river stage can be converted to streamflow and traveltimes.

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

PubMed Central

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett; Gati, Cornelius; Kimura, Tetsunari; Milne, Christopher; Milathianaki, Despina; Kubo, Minoru; Wu, Wenting; Conrad, Chelsie; Coe, Jesse; Bean, Richard; Zhao, Yun; Båth, Petra; Dods, Robert; Harimoorthy, Rajiv; Beyerlein, Kenneth R.; Rheinberger, Jan; James, Daniel; DePonte, Daniel; Li, Chufeng; Sala, Leonardo; Williams, Garth J.; Hunter, Mark S.; Koglin, Jason E.; Berntsen, Peter; Nango, Eriko; Iwata, So; Chapman, Henry N.; Fromme, Petra; Frank, Matthias; Abela, Rafael; Boutet, Sébastien; Barty, Anton; White, Thomas A.; Weierstall, Uwe; Spence, John; Neutze, Richard; Schertler, Gebhard; Standfuss, Jörg

2016-01-01

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX. PMID:27545823

Annual replenishment of bed material by sediment transport in the Wind River near Riverton, Wyoming

USGS Publications Warehouse

Smalley, M.L.; Emmett, W.W.; Wacker, A.M.

1994-01-01

The U.S. Geological Survey, in cooperation with the Wyoming Department of Transportation, conducted a study during 1985-87 to determine the annual replenishment of sand and gravel along a point bar in the Wind River near Riverton, Wyoming. Hydraulic- geometry relations determined from streamflow measurements; streamflow characteristics determined from 45 years of record at the study site; and analyses of suspended-sediment, bedload, and bed- material samples were used to describe river transport characteristics and to estimate the annual replenishment of sand and gravel. The Wind River is a perennial, snowmelt-fed stream. Average daily discharge at the study site is about 734 cubic feet per second, and bankfull discharge (recurrence interval about 1.5 years) is about 5,000 cubic feet per second. At bankfull discharge, the river is about 136 feet wide and has an average depth of about 5.5 feet and average velocity of about 6.7 feet per second. Streams slope is about 0.0010 foot per foot. Bed material sampled on the point bar before the 1986 high flows ranged from sand to cobbles, with a median diameter of about 22 millimeters. Data for sediment samples collected during water year 1986 were used to develop regression equations between suspended-sediment load and water discharge and between bedload and water discharge. Average annual suspended-sediment load was computed to be about 561,000 tons per year using the regression equation in combination with flow-duration data. The regression equation for estimating bedload was not used; instead, average annual bedload was computed as 1.5 percent of average annual suspended load about 8,410 tons per year. This amount of bedload material is estimated to be in temporary storage along a reach containing seven riffles--a length of approximately 1 river mile. On the basis of bedload material sampled during the 1986 high flows, about 75 percent (by weight) is sand (2 millimeters in diameter or finer); median particle size is about 0.5 milli- meter. About 20 percent (by weight) is medium gravel to small cobbles--12.7 millimeters (0.5 inch) or coarser. The bedload moves slowly (about 0.03 percent of the water speed) and briefly (about 10 percent of the time). The average travel distance of a median-sized particle is about 1 river mile per year. The study results indicate that the average replenishment rate of bedload material coarser than 12.7 millimeters is about 1,500 to 2,000 tons (less than 1,500 cubic yards) per year. Finer material (0.075 to 6.4 millimeters in diameter) is replen- ishment at about 4,500 to 5,000 cubic yards per year. The total volume of potentially usable material would average about 6,000 cubic yards per year.

Spatial resolution limits for the isotropic-3D PET detector X’tal cube

NASA Astrophysics Data System (ADS)

Yoshida, Eiji; Tashima, Hideaki; Hirano, Yoshiyuki; Inadama, Naoko; Nishikido, Fumihiko; Murayama, Hideo; Yamaya, Taiga

2013-11-01

Positron emission tomography (PET) has become a popular imaging method in metabolism, neuroscience, and molecular imaging. For dedicated human brain and small animal PET scanners, high spatial resolution is needed to visualize small objects. To improve the spatial resolution, we are developing the X’tal cube, which is our new PET detector to achieve isotropic 3D positioning detectability. We have shown that the X’tal cube can achieve 1 mm3 uniform crystal identification performance with the Anger-type calculation even at the block edges. We plan to develop the X’tal cube with even smaller 3D grids for sub-millimeter crystal identification. In this work, we investigate spatial resolution of a PET scanner based on the X’tal cube using Monte Carlo simulations for predicting resolution performance in smaller 3D grids. For spatial resolution evaluation, a point source emitting 511 keV photons was simulated by GATE for all physical processes involved in emission and interaction of positrons. We simulated two types of animal PET scanners. The first PET scanner had a detector ring 14.6 cm in diameter composed of 18 detectors. The second PET scanner had a detector ring 7.8 cm in diameter composed of 12 detectors. After the GATE simulations, we converted the interacting 3D position information to digitalized positions for realistic segmented crystals. We simulated several X’tal cubes with cubic crystals from (0.5 mm)3 to (2 mm)3 in size. Also, for evaluating the effect of DOI resolution, we simulated several X’tal cubes with crystal thickness from (0.5 mm)3 to (9 mm)3. We showed that sub-millimeter spatial resolution was possible using cubic crystals smaller than (1.0 mm)3 even with the assumed physical processes. Also, the weighted average spatial resolutions of both PET scanners with (0.5 mm)3 cubic crystals were 0.53 mm (14.6 cm ring diameter) and 0.48 mm (7.8 cm ring diameter). For the 7.8 cm ring diameter, spatial resolution with 0.5×0.5×1.0 mm3 crystals was improved 39% relative to the (1 mm)3 cubic crystals. On the other hand, spatial resolution with (0.5 mm)3 cubic crystals was improved 47% relative to the (1 mm)3 cubic crystals. The X’tal cube promises better spatial resolution for the 3D crystal block with isotropic resolution.

Deformation-induced structural transition in body-centred cubic molybdenum

PubMed Central

Wang, S. J.; Wang, H.; Du, K.; Zhang, W.; Sui, M. L.; Mao, S. X.

2014-01-01

Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original <001>-oriented body-centred cubic structure to a <110>-oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into <111>-oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama–Wassermann and Kurdjumov–Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions. PMID:24603655

Eliminating cubic terms in the pseudopotential lattice Boltzmann model for multiphase flow

NASA Astrophysics Data System (ADS)

Huang, Rongzong; Wu, Huiying; Adams, Nikolaus A.

2018-05-01

It is well recognized that there exist additional cubic terms of velocity in the lattice Boltzmann (LB) model based on the standard lattice. In this work, elimination of these cubic terms in the pseudopotential LB model for multiphase flow is investigated, where the force term and density gradient are considered. By retaining high-order (≥3 ) Hermite terms in the equilibrium distribution function and the discrete force term, as well as introducing correction terms in the LB equation, the additional cubic terms of velocity are entirely eliminated. With this technique, the computational simplicity of the pseudopotential LB model is well maintained. Numerical tests, including stationary and moving flat and circular interface problems, are carried out to show the effects of such cubic terms on the simulation of multiphase flow. It is found that the elimination of additional cubic terms is beneficial to reduce the numerical error, especially when the velocity is relatively large. Numerical results also suggest that these cubic terms mainly take effect in the interfacial region and that the density-gradient-related cubic terms are more important than the other cubic terms for multiphase flow.

A bicontinuous tetrahedral structure in a liquid-crystalline lipid

NASA Astrophysics Data System (ADS)

Longley, William; McIntosh, Thomas J.

1983-06-01

The structure of most lipid-water phases can be visualized as an ordered distribution of two liquid media, water and hydrocarbons, separated by a continuous surface covered by the polar groups of the lipid molecules1. In the cubic phases in particular, rod-like elements are linked into three-dimensional networks1,2. Two of these phases (space groups Ia3d and Pn3m) contain two such three-dimensional networks mutually inter-woven and unconnected. Under the constraints of energy minimization3, the interface between the components in certain of these `porous fluids' may well resemble one of the periodic minimal surface structures of the type described mathematically by Schwarz4,5. A structure of this sort has been proposed for the viscous isotropic (cubic) form of glycerol monooleate (GMO) by Larsson et al.6 who suggested that the X-ray diagrams of Lindblom et al.7 indicated a body-centred crystal structure in which lipid bilayers might be arranged as in Schwarz's octahedral surface4. We have now found that at high water contents, a primitive cubic lattice better fits the X-ray evidence with the material in the crystal arranged in a tetrahedral way. The lipid appears to form a single bilayer, continuous in three dimensions, separating two continuous interlinked networks of water. Each of the water networks has the symmetry of the diamond crystal structure and the bilayer lies in the space between them following a surface resembling Schwarz's tetrahedral surface4.

Evaluation of rapid progressors in HIV infection as an extreme phenotype.

PubMed

Olson, Ashley D; Guiguet, Marguerite; Zangerle, Robert; Gill, John; Perez-Hoyos, Santiago; Lodi, Sara; Ghosn, Jade; Dorrucci, Maria; Johnson, Anne; Sannes, Mette; Moreno, Santiago; Porter, Kholoud

2014-09-01

Rapid CD4 cell loss represents an HIV phenotype used to identify causal variants of accelerated disease progression. The optimal rate and threshold for identifying this extreme phenotype in recently infected individuals is unclear. Using a cohort of patients with known dates of HIV-1 seroconversion (SC), CASCADE (Concerted Action on SeroConversion on AIDS and Death in Europe), we identified proportions experiencing nadir CD4 cell levels within 1 year of SC, and assessed their mean AIDS-free survival time at 10-year follow-up and hazard of AIDS/death, compared with those whose CD4 remained >500 cells per cubic millimeter. Follow-up was censored at December 31, 1996 to avoid bias due to combination antiretroviral therapy initiation. Of 4876 individuals, 2.8%, 7.3%, and 24.9% experienced ≥1 CD4 <100, 200, and 350 cells per cubic millimeter, respectively, within 1 year of SC. Minimum CD4 levels of 30, 166, 231, and 506 cells per cubic millimeter were experienced during this period by 1%, 5%, 10%, and 50% of individuals, respectively. Mean (95% confidence interval) AIDS-free survival at 10 years follow-up was 2.9 (2.3 to 3.6), 5.5 (5.0 to 6.1), 6.7 (6.5 to 7.0), 7.4 (7.2 to 7.6), and 8.1 (7.9 to 8.3), for those with minimum counts ≤100, 100-200, 200-350, 350-500, >500 cells per cubic millimeter, respectively. Using counts of >500 cells per cubic millimeter as reference, the hazard ratios (95% confidence interval) of AIDS/death were 15.0 (11.9 to 18.9), 3.6 (2.9 to 4.5), 2.1 (1.8 to 2.4), and 1.5 (1.3 to 1.7), respectively. The hazard ratio increased to 37.5 (26.5 to 53.1) when a minimum CD4 count <100 was confirmed within 1 year of SC. At least 1 CD4 ≤100 cells per cubic millimeter within the first year of SC identifies a rare group of individuals at high risk of disease progression and could form the basis for defining the rapid progressor phenotype.

Floods of April 28, 1966 in the northern part of Dallas, Texas

USGS Publications Warehouse

Mills, Willard B.; Schroeder, Elmer E.

1969-01-01

The flood was caused by a 5-hour storm in the early hours of April 28. Antecedent rainfall had so saturated the area that the intense, but relatively low, total rainfall (less than a 50-year return period) caused historical floods to be exceeded at many points. A peak runoff rate of 3,160 cubic feet per second per square mile occurred on a 1.5 square-mile area within the watershed.

Prevention of Hydrogen-Induced Cracking in HY-130 Weldments.

DTIC Science & Technology

1977-09-30

cubic delta ferrite at the melting point (1538 C). The solu- bility increases from about k.9 to 8.3 ppm when delta ferrite transforms to * 3 The H... ferrite at 912 C. The solubility in ferrite then de- creases to less than 0.5 ppm at ambient temperature. This theory postulates that atomic...content than the dark- etching bands, and thus correspond to the regions last to freeze between the dendritic arms in the original ingot. During

An Unconditionally Monotone C 2 Quartic Spline Method with Nonoscillation Derivatives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Jin; Nelson, Karl E.

Here, a one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C 2 and unconditionally monotone. A set of control points is employed to constrain the curvature of the interpolation function and to eliminate possible nonphysical oscillations in the slope space. An extension of this method in two-dimensions is also discussed.

An Unconditionally Monotone C 2 Quartic Spline Method with Nonoscillation Derivatives

DOE PAGES

Yao, Jin; Nelson, Karl E.

2018-01-24

Here, a one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C 2 and unconditionally monotone. A set of control points is employed to constrain the curvature of the interpolation function and to eliminate possible nonphysical oscillations in the slope space. An extension of this method in two-dimensions is also discussed.

Structural and optical properties of NiFe2O4 synthesized via green technology

NASA Astrophysics Data System (ADS)

Patel, S.; Saleem, M.; Varshney, Dinesh

2018-05-01

The nanoparticles of NiFe2O4 were successfully synthesized via green technology using banana peel extract as the catalyst as well as the medium for reaction technique is reported. Analysis of X-ray diffraction spectrum revealed the cubic structure for the prepared spinel ferrite samples crystallized into cubic spinel structure with the space group Fd3m. The Retvield refinement was carried out which obeyed the results obtained from the XRD spectrum analysis of the sample. Raman spectrum provided confirmation for the spinel structure formation and five active Raman modes were observed. Since the optical band-gap value shows inverse response to the crystallite size, The UV-Vis spectrum study confirmed dual but reduced band-gap value.

Investigation of LiF, Mg and Ti (TLD-100) Reproducibility

PubMed Central

Sadeghi, M.; Sina, S.; Faghihi, R.

2015-01-01

LiF, Mg and Ti cubical TLD chips (known as TLD-100) are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy) with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC) were obtained 4 times by irradiating them to doses of 81 mGy (two times), 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%. PMID:26688801

Investigation of LiF, Mg and Ti (TLD-100) Reproducibility.

PubMed

Sadeghi, M; Sina, S; Faghihi, R

2015-12-01

LiF, Mg and Ti cubical TLD chips (known as TLD-100) are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy) with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC) were obtained 4 times by irradiating them to doses of 81 mGy (two times), 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%.

TU-D-207B-01: A Prediction Model for Distinguishing Radiation Necrosis From Tumor Progression After Gamma Knife Radiosurgery Based On Radiomics Features From MR Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Z; MD Anderson Cancer Center, Houston, TX; Ho, A

Purpose: To develop and validate a prediction model using radiomics features extracted from MR images to distinguish radiation necrosis from tumor progression for brain metastases treated with Gamma knife radiosurgery. Methods: The images used to develop the model were T1 post-contrast MR scans from 71 patients who had had pathologic confirmation of necrosis or progression; 1 lesion was identified per patient (17 necrosis and 54 progression). Radiomics features were extracted from 2 images at 2 time points per patient, both obtained prior to resection. Each lesion was manually contoured on each image, and 282 radiomics features were calculated for eachmore » lesion. The correlation for each radiomics feature between two time points was calculated within each group to identify a subset of features with distinct values between two groups. The delta of this subset of radiomics features, characterizing changes from the earlier time to the later one, was included as a covariate to build a prediction model using support vector machines with a cubic polynomial kernel function. The model was evaluated with a 10-fold cross-validation. Results: Forty radiomics features were selected based on consistent correlation values of approximately 0 for the necrosis group and >0.2 for the progression group. In performing the 10-fold cross-validation, we narrowed this number down to 11 delta radiomics features for the model. This 11-delta-feature model showed an overall prediction accuracy of 83.1%, with a true positive rate of 58.8% in predicting necrosis and 90.7% for predicting tumor progression. The area under the curve for the prediction model was 0.79. Conclusion: These delta radiomics features extracted from MR scans showed potential for distinguishing radiation necrosis from tumor progression. This tool may be a useful, noninvasive means of determining the status of an enlarging lesion after radiosurgery, aiding decision-making regarding surgical resection versus conservative medical management.« less

Assessment of second-line antiretroviral regimens for HIV therapy in Africa.

PubMed

Paton, Nicholas I; Kityo, Cissy; Hoppe, Anne; Reid, Andrew; Kambugu, Andrew; Lugemwa, Abbas; van Oosterhout, Joep J; Kiconco, Mary; Siika, Abraham; Mwebaze, Raymond; Abwola, Mary; Abongomera, George; Mweemba, Aggrey; Alima, Hillary; Atwongyeire, Dickens; Nyirenda, Rose; Boles, Justine; Thompson, Jennifer; Tumukunde, Dinah; Chidziva, Ennie; Mambule, Ivan; Arribas, Jose R; Easterbrook, Philippa J; Hakim, James; Walker, A Sarah; Mugyenyi, Peter

2014-07-17

The efficacy and toxic effects of nucleoside reverse-transcriptase inhibitors (NRTIs) are uncertain when these agents are used with a protease inhibitor in second-line therapy for human immunodeficiency virus (HIV) infection in resource-limited settings. Removing the NRTIs or replacing them with raltegravir may provide a benefit. In this open-label trial in sub-Saharan Africa, we randomly assigned 1277 adults and adolescents with HIV infection and first-line treatment failure to receive a ritonavir-boosted protease inhibitor (lopinavir-ritonavir) plus clinician-selected NRTIs (NRTI group, 426 patients), a protease inhibitor plus raltegravir in a superiority comparison (raltegravir group, 433 patients), or protease-inhibitor monotherapy after 12 weeks of induction therapy with raltegravir in a noninferiority comparison (monotherapy group, 418 patients). The primary composite end point, good HIV disease control, was defined as survival with no new World Health Organization stage 4 events, a CD4+ count of more than 250 cells per cubic millimeter, and a viral load of less than 10,000 copies per milliliter or 10,000 copies or more with no protease resistance mutations at week 96 and was analyzed with the use of imputation of data (≤4%). Good HIV disease control was achieved in 60% of the patients (mean, 255 patients) in the NRTI group, 64% of the patients (mean, 277) in the raltegravir group (P=0.21 for the comparison with the NRTI group; superiority of raltegravir not shown), and 55% of the patients (mean, 232) in the monotherapy group (noninferiority of monotherapy not shown, based on a 10-percentage-point margin). There was no significant difference in rates of grade 3 or 4 adverse events among the three groups (P=0.82). The viral load was less than 400 copies per milliliter in 86% of patients in the NRTI group, 86% in the raltegravir group (P=0.97), and 61% in the monotherapy group (P<0.001). When given with a protease inhibitor in second-line therapy, NRTIs retained substantial virologic activity without evidence of increased toxicity, and there was no advantage to replacing them with raltegravir. Virologic control was inferior with protease-inhibitor monotherapy. (Funded by European and Developing Countries Clinical Trials Partnership and others; EARNEST Current Controlled Trials number, ISRCTN37737787, and ClinicalTrials.gov number, NCT00988039.).

Thermodynamics of hairy black holes in Lovelock gravity

NASA Astrophysics Data System (ADS)

Hennigar, Robie A.; Tjoa, Erickson; Mann, Robert B.

2017-02-01

We perform a thorough study of the thermodynamic properties of a class of Lovelock black holes with conformal scalar hair arising from coupling of a real scalar field to the dimensionally extended Euler densities. We study the linearized equations of motion of the theory and describe constraints under which the theory is free from ghosts/tachyons. We then consider, within the context of black hole chemistry, the thermodynamics of the hairy black holes in the Gauss-Bonnet and cubic Lovelock theories. We clarify the connection between isolated critical points and thermodynamic singularities, finding a one parameter family of these critical points which occur for well-defined thermodynamic parameters. We also report on a number of novel results, including `virtual triple points' and the first example of a `λ-line' — a line of second order phase transitions — in black hole thermodynamics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linaburg, Matthew R.; McClure, Eric T.; Majher, Jackson D.

The structures of the lead halide perovskites CsPbCl3 and CsPbBr3 have been determined from X-ray powder diffraction data to be orthorhombic with Pnma space group symmetry. Their structures are distorted from the cubic structure of their hybrid analogs, CH3NH3PbX3 (X = Cl, Br), by tilts of the octahedra (Glazer tilt system a–b+a–). Substitution of the smaller Rb+ for Cs+ increases the octahedral tilting distortion and eventually destabilizes the perovskite structure altogether. To understand this behavior, bond valence parameters appropriate for use in chloride and bromide perovskites have been determined for Cs+, Rb+, and Pb2+. As the tolerance factor decreases, themore » band gap increases, by 0.15 eV in Cs1–xRbxPbCl3 and 0.20 eV in Cs1–xRbxPbBr3, upon going from x = 0 to x = 0.6. The band gap shows a linear dependence on tolerance factor, particularly for the Cs1–xRbxPbBr3 system. Comparison with the cubic perovskites CH3NH3PbCl3 and CH3NH3PbBr3 shows that the band gaps of the methylammonium perovskites are anomalously large for APbX3 perovskites with a cubic structure. This comparison suggests that the local symmetry of CH3NH3PbCl3 and CH3NH3PbBr3 deviate significantly from the cubic symmetry of the average structure.« less

The South’s timber industry - an assessment of timber product output and use, 2009

Treesearch

Tony G. Johnson; James W. Bentley; Mike Howell

2011-01-01

In 2009, industrial roundwood output from the South’s forests totaled 6.56 billion cubic feet, 20 percent less than in 2007. Pulpwood was the leading roundwood product at 3.43 billion cubic feet; saw logs ranked second at 2.26 billion cubic feet; veneer logs were third at 384.4 million cubic feet. Total receipts declined 21 percent to 6.55 billion cubic feet. Mill...

Thermal stability and phase transformation in fully indium oxide (InO{sub 1.5}) stabilized zirconia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piva, R.H., E-mail: honorato.piva@ua.pt; Piva, D.H

2017-01-15

Indium oxide (InO{sub 1.5}) stabilized zirconia (InSZ) is an attractive material as electrolyte, or electrode, in solid oxide fuel cells (SOFCs), and as corrosion resistant top coat in thermal barrier coatings. However, little is known about the phase stability of cubic InSZ at temperatures that simulate the conditions in an operating SOFC or turbine. This article provides an investigation of the phase stability and phase transformations in cubic InSZ after heat treatments at 800, 1000, and 1200 °C for periods up to 2000 h. The results revealed that cubic InSZ is not stable during annealing at 1000 and 1200 °C,more » owing to a fast destabilization of the initial cubic phase to tetragonal, and eventually to monoclinic (c → t → m). The c → t → m transition in InSZ is intimately associated with the indium volatilization. On the other hand, cubic InSZ remained stable for 2000 h at 800 °C, although the partial formation of the tetragonal phase was observed along with a 0.25% contraction in the unit cell volume of the cubic phase, caused by short-range ordering. These results demonstrate that technological applications of cubic InSZ are restricted to temperatures at which the volatilization of the InO{sub 1.5} stabilizer does not occur. - Highlights: •Phase stability of fully InO{sub 1.5} stabilized zirconia (cubic InSZ) was evaluated. •Cubic InSZ is instable at temperatures ≥ 1000 °C, owing to the cubic-to-tetragonal-to-monoclinic destabilization. •Cubic InSZ undergoes the cubic-to-tetragonal transformation at ~ 800 °C. •Owing to the low phase stability, applications of cubic InSZ in TBCs or SOFCs are restricted.« less

Calculations of and evidence for chain packing stress in inverse lyotropic bicontinuous cubic phases.

PubMed

Shearman, Gemma C; Khoo, Bee J; Motherwell, Mary-Lynn; Brakke, Kenneth A; Ces, Oscar; Conn, Charlotte E; Seddon, John M; Templer, Richard H

2007-06-19

Inverse bicontinuous cubic lyotropic phases are a complex solution to the dilemma faced by all self-assembled water-amphiphile systems: how to satisfy the incompatible requirements for uniform interfacial curvature and uniform molecular packing. The solution reached in this case is for the water-amphiphile interfaces to deform hyperbolically onto triply periodic minimal surfaces. We have previously suggested that although the molecular packing in these structures is rather uniform the relative phase behavior of the gyroid, double diamond, and primitive inverse bicontinuous cubic phases can be understood in terms of subtle differences in packing frustration. In this work, we have calculated the packing frustration for these cubics under the constraint that their interfaces have constant mean curvature. We find that the relative packing stress does indeed differ between phases. The gyroid cubic has the least packing stress, and at low water volume fraction, the primitive cubic has the greatest packing stress. However, at very high water volume fraction, the double diamond cubic becomes the structure with the greatest packing stress. We have tested the model in two ways. For a system with a double diamond cubic phase in excess water, the addition of a hydrophobe may release packing frustration and preferentially stabilize the primitive cubic, since this has previously been shown to have lower curvature elastic energy. We have confirmed this prediction by adding the long chain alkane tricosane to 1-monoolein in excess water. The model also predicts that if one were able to hydrate the double diamond cubic to high water volume fractions, one should destabilize the phase with respect to the primitive cubic. We have found that such highly swollen metastable bicontinuous cubic phases can be formed within onion vesicles. Data from monoelaidin in excess water display a well-defined transition, with the primitive cubic appearing above a water volume fraction of 0.75. Both of these results lend support to the proposition that differences in the packing frustration between inverse bicontinuous cubic phases play a pivotal role in their relative phase stability.

X-Ray Crystallographic Studies of Electrostatic Effects in Cubic Insulin

NASA Astrophysics Data System (ADS)

Gursky, Olga

1992-09-01

Cubic crystals of bovine insulin were obtained at pH 9 from sodium phosphate buffer. Pathway dependence of crystallization was analysed and crystallization using controlled nucleation was developed. Crystal stability and solubility were surveyed by dialysing the crystals against salt solutions varying in salt composition and ionic strength. Crystals dialysed in 0.1-0.2M Li, Na, K, Rb, NH(4) or Tl salt solutions at pH 9 diffracted to beyond 2.8A, while crystals dialysed in Cs, Mg, Ca or La rapidly lost lattice order. Change in the solvent anion did not affect crystal stability. Electron density maps calculated from X-ray data to 2.8A resolution showed two specific cation binding sites which may be occupied by monovalent cations with ionic radii <1.5A. One site lies between insulin dimers near crystallographic two-fold axis without the close involvement of protein charged groups. Cation binding at this site is important for crystal stability. The other site is alternatively occupied by B10 His in one of its two conformations. At pH 7, the Tl occupancy at both sites was decreased, at pH 9.5 the Tl occupancy of the site near B10 His was increased. The structure was refined using the refined model of cubic porcine insulin and the X-ray data collected to 2A resolution from a bovine insulin crystal at pH 9, to R = 16.1% for the data extending from 10A to 2A. High -resolution data from crystals at pH 7 and pH 10 were collected and analysed. The weights of the two B10 His conformers and the cation occupancy near B10 vary in the pH range from 7 to 10, indicating histidine titration. Shifts in the positions of B1-B4 at pH 7 suggest titration of the B-chain terminal amino groups. Co-operative conformational changes in the surface charged residues A1, A4, B21, B29, B30 at pH 10.2 suggest titration of the A-chain terminal amino groups. In several crystals treated with dichloroethane, the syn-dichloroethane was bound in the niche across the two-fold axis connecting insulin monomers. Dichloroethane binding does not perturb the site geometry and probably leads to cubic insulin preparations of increased stability.

Bifurcations and stability of standing waves in the nonlinear Schrödinger equation on the tadpole graph

NASA Astrophysics Data System (ADS)

Noja, Diego; Pelinovsky, Dmitry; Shaikhova, Gaukhar

2015-07-01

We develop a detailed analysis of edge bifurcations of standing waves in the nonlinear Schrödinger (NLS) equation on a tadpole graph (a ring attached to a semi-infinite line subject to the Kirchhoff boundary conditions at the junction). It is shown in the recent work [7] by using explicit Jacobi elliptic functions that the cubic NLS equation on a tadpole graph admits a rich structure of standing waves. Among these, there are different branches of localized waves bifurcating from the edge of the essential spectrum of an associated Schrödinger operator. We show by using a modified Lyapunov-Schmidt reduction method that the bifurcation of localized standing waves occurs for every positive power nonlinearity. We distinguish a primary branch of never vanishing standing waves bifurcating from the trivial solution and an infinite sequence of higher branches with oscillating behavior in the ring. The higher branches bifurcate from the branches of degenerate standing waves with vanishing tail outside the ring. Moreover, we analyze stability of bifurcating standing waves. Namely, we show that the primary branch is composed by orbitally stable standing waves for subcritical power nonlinearities, while all nontrivial higher branches are linearly unstable near the bifurcation point. The stability character of the degenerate branches remains inconclusive at the analytical level, whereas heuristic arguments based on analysis of embedded eigenvalues of negative Krein signatures support the conjecture of their linear instability at least near the bifurcation point. Numerical results for the cubic NLS equation show that this conjecture is valid and that the degenerate branches become spectrally stable far away from the bifurcation point.

Specific storage volumes: A useful tool for CO2 storage capacity assessment

USGS Publications Warehouse

Brennan, S.T.; Burruss, R.C.

2006-01-01

Subsurface geologic strata have the potential to store billions of tons of anthropogenic CO2; therefore, geologic carbon sequestration can be an effective mitigation tool used to slow the rate at which levels of atmospheric CO2 are increasing. Oil and gas reservoirs, coal beds, and saline reservoirs can be used for CO2 storage; however, it is difficult to assess and compare the relative storage capacities of these different settings. Typically, CO2 emissions are reported in units of mass, which are not directly applicable to comparing the CO2 storage capacities of the various storage targets. However, if the emission values are recalculated to volumes per unit mass (specific volume) then the volumes of geologic reservoirs necessary to store CO2 emissions from large point sources can be estimated. The factors necessary to convert the mass of CO2 emissions to geologic storage volume (referred to here as Specific Storage Volume or 'SSV') can be reported in units of cubic meters, cubic feet, and petroleum barrels. The SSVs can be used to estimate the reservoir volume needed to store CO2 produced over the lifetime of an individual point source, and to identify CO2 storage targets of sufficient size to meet the demand from that given point source. These storage volumes also can then be projected onto the land surface to outline a representative "footprint," which marks the areal extent of storage. This footprint can be compared with the terrestrial carbon sequestration capacity of the same land area. The overall utility of this application is that the total storage capacity of any given parcel of land (from surface to basement) can be determined, and may assist in making land management decisions. ?? Springer Science+Business Media, LLC 2006.

Hanging angles of two electrostatically repelling pith balls of different masses

NASA Astrophysics Data System (ADS)

Tran, Phuc G.; Mungan, Carl E.

2011-09-01

An analytic solution can be derived for the angles of two mutually repelling charged pith balls of unequal mass hanging from strings from a common point of attachment. Just as in the equal-mass case, a cubic equation is found for the square of the sine of either angle, and an approximation can be used to avoid Cardano's formula for small angles. These results extend a standard problem treated in introductory undergraduate courses in electricity and magnetism.

Reconnaissance Report, Small Navigation Project Section 107, Palmetto and Soldier Creeks, Baldwin County, Alabama

DTIC Science & Technology

1990-06-01

McMillan, Representative, Alabama Legislature Neil Lauder , Baldwin County Commission Percy C. Nixon, Baldwin County Engineer Albert P. Elebash, The Point...removal of 1500 cubic yards and their best bid to date is $15,000. Both Mr. Elebash and Mr. Southey believe that they will be able to raise the money ...support costs of this magnitude over the long term. A-4 3. Mr. Lauder and Mr. Nixon have been investigating other sources for some of the funds and

Automated Cartography by an Autonomous Mobile Robot Using Ultrasonic Range Finders

DTIC Science & Technology

1993-09-01

loco.c Temporal Type: Sequential Function (xd, yd, td, 0) dirctix vehicle fou TP S~obstacle IP EP Figure A.24 - The para function Move to a... tp (type POINT), and type (type int). In the case of an fline func- tion, the path element returned is a cubic spiral or an sline depending on the...geu~nst-> tp )) I --no_o...paths; currentsroboLpath.pc = get inst->c; currentLrobot...path.type = getLinst->class; readjinsto; )*end if * if (skipjflag

Bi-cubic interpolation for shift-free pan-sharpening

NASA Astrophysics Data System (ADS)

Aiazzi, Bruno; Baronti, Stefano; Selva, Massimo; Alparone, Luciano

2013-12-01

Most of pan-sharpening techniques require the re-sampling of the multi-spectral (MS) image for matching the size of the panchromatic (Pan) image, before the geometric details of Pan are injected into the MS image. This operation is usually performed in a separable fashion by means of symmetric digital low-pass filtering kernels with odd lengths that utilize piecewise local polynomials, typically implementing linear or cubic interpolation functions. Conversely, constant, i.e. nearest-neighbour, and quadratic kernels, implementing zero and two degree polynomials, respectively, introduce shifts in the magnified images, that are sub-pixel in the case of interpolation by an even factor, as it is the most usual case. However, in standard satellite systems, the point spread functions (PSF) of the MS and Pan instruments are centered in the middle of each pixel. Hence, commercial MS and Pan data products, whose scale ratio is an even number, are relatively shifted by an odd number of half pixels. Filters of even lengths may be exploited to compensate the half-pixel shifts between the MS and Pan sampling grids. In this paper, it is shown that separable polynomial interpolations of odd degrees are feasible with linear-phase kernels of even lengths. The major benefit is that bi-cubic interpolation, which is known to represent the best trade-off between performances and computational complexity, can be applied to commercial MS + Pan datasets, without the need of performing a further half-pixel registration after interpolation, to align the expanded MS with the Pan image.

Extent and relevance of stacking disorder in “ice Ic”

PubMed Central

Kuhs, Werner F.; Sippel, Christian; Falenty, Andrzej; Hansen, Thomas C.

2012-01-01

A solid water phase commonly known as “cubic ice” or “ice Ic” is frequently encountered in various transitions between the solid, liquid, and gaseous phases of the water substance. It may form, e.g., by water freezing or vapor deposition in the Earth’s atmosphere or in extraterrestrial environments, and plays a central role in various cryopreservation techniques; its formation is observed over a wide temperature range from about 120 K up to the melting point of ice. There was multiple and compelling evidence in the past that this phase is not truly cubic but composed of disordered cubic and hexagonal stacking sequences. The complexity of the stacking disorder, however, appears to have been largely overlooked in most of the literature. By analyzing neutron diffraction data with our stacking-disorder model, we show that correlations between next-nearest layers are clearly developed, leading to marked deviations from a simple random stacking in almost all investigated cases. We follow the evolution of the stacking disorder as a function of time and temperature at conditions relevant to atmospheric processes; a continuous transformation toward normal hexagonal ice is observed. We establish a quantitative link between the crystallite size established by diffraction and electron microscopic images of the material; the crystallite size evolves from several nanometers into the micrometer range with progressive annealing. The crystallites are isometric with markedly rough surfaces parallel to the stacking direction, which has implications for atmospheric sciences. PMID:23236184

Toward a theory of energetically optimal body size in growing animals.

PubMed

Hannon, B M; Murphy, M R

2016-06-01

Our objective was to formulate a general and useful model of the energy economy of the growing animal. We developed a theory that the respiratory energy per unit of size reaches a minimum at a particular point, when the marginal respiratory heat production rate is equal to the average rate. This occurs at what we defined as the energetically optimal size for the animal. The relationship between heat production rate and size was found to be well described by a cubic function in which heat production rate accelerates as the animal approaches and then exceeds its optimal size. Reanalysis of energetics data from the literature often detected cubic curvature in the relationship between heat production rate and body size of fish, rats, chickens, goats, sheep, swine, cattle, and horses. This finding was consistent with the theory for 13 of 17 data sets. The bias-corrected Akaike information criterion indicated that the cubic equation modeled the influence of the size of a growing animal on its heat production rate better than a power function for 11 of 17 data sets. Changes in the sizes and specific heat production rates of metabolically active internal organs, and body composition and tissue turnover rates were found to explain notable portions of the expected increase in heat production rate as animals approached and then exceeded their energetically optimum size. Accelerating maintenance costs in this region decrease net energy available for productive functions. Energetically and economically optimum size criteria were also compared.

Elastic excitations in BaTiO3 single crystals and ceramics: Mobile domain boundaries and polar nanoregions observed by resonant ultrasonic spectroscopy

NASA Astrophysics Data System (ADS)

Salje, Ekhard K. H.; Carpenter, Michael A.; Nataf, Guillaume F.; Picht, Gunnar; Webber, Kyle; Weerasinghe, Jeevaka; Lisenkov, S.; Bellaiche, L.

2013-01-01

The dynamic properties of elastic domain walls in BaTiO3 were investigated using resonance ultrasonic spectroscopy (RUS). The sequence of phase transitions is characterized by minima in the temperature dependence of RUS resonance frequencies and changes in Q factors (resonance damping). Damping is related to the friction of mobile twin boundaries (90° ferroelectric walls) and distorted polar nanoregions (PNRs) in the cubic phase. Damping is largest in the tetragonal phase of ceramic materials but very low in single crystals. Damping is also small in the low-temperature phases of the ceramic sample and slightly increases with decreasing temperature in the single crystal. The phase angle between the real and imaginary part of the dynamic response function changes drastically in the cubic and tetragonal phases and remains constant in the orthorhombic phase. Other phases show a moderate dependence of the phase angle on temperature showing systematic changes of twin microstructures. Mobile twin boundaries (or sections of twin boundaries such as kinks inside twin walls) contribute strongly to the energy dissipation of the forced oscillation while the reduction in effective modulus due to relaxing twin domains is weak. Single crystals and ceramics show strong precursor softening in the cubic phase related to polar nanoregions (PNRs). The effective modulus decreases when the transition point of the cubic-tetragonal transformation is approached from above. The precursor softening follows temperature dependence very similar to recent results from Brillouin scattering. Between the Burns temperature (≈586 K) and Tc at 405 K, we found a good fit of the squared RUS frequency [˜Δ (C11-C12)] to a Vogel-Fulcher process with an activation energy of ˜0.2 eV. Finally, some first-principles-based effective Hamiltonian computations were carried out in BaTiO3 single domains to explain some of these observations in terms of the dynamics of the soft mode and central mode.

Ground-water flow and quality near the Upper Great Lakes connecting channels, Michigan

USGS Publications Warehouse

Gillespie, J.L.; Dumouchelle, D.H.

1989-01-01

The Upper Great Lakes connecting channels are the St. Marys, St. Clair and Detroit Rivers, and Lake St. Clair. The effect of ground water on the connecting channels is largely unknown, and the controls on its movement and quality are undefined. Geologic, hydrologic, and environmental conditions near the channels have been examined.for this investigation. Included in the study area is a 50-mile reach of channel beginning at Whitefish Bay and extending to Neebish Island, and a 90-mile reach of channel between Port Huron and Pointe Mouillee in Lake Erie. Glacial deposits, which transmit most ground water to the channels, range from less than 100 feet in thickness in the southern part of the St. Clair-Detroit River area to more than 250 feet in thickness in the northern part. Marine seismic surveys were used at some locations to determine the thickness of deposits. Glacial deposits in the St. Marys River area range from less than 10 feet to more than 300 feet in thickness. Permeable bedrock in the southern reach of the Detroit River area and throughout most of the St. Marys River area may contribute substantial amounts of water to the channels. Total ground-water discharge to the channels, by area, is estimated as follows! St. Marys area, 76 cubic feet per second; St. Clair area, 11 cubic feet per second; Lake St. Clair area, 46 cubic feet per second; and Detroit area, 54 cubic feet per second. Analyses of water from 31 wells, 25 of which were installed by the U.S. Geological Survey, were made for organic compounds, trace metals, and other substances. Volatile hydrocarbons, and base neutral, acid extractable, and chlorinated neutral compounds were not detectable in water at most locations. Concentrations of trace metals, however, were higher than common in natural waters at some locations.

Effect of fatty acids on self-assembly of soybean lecithin systems.

PubMed

Godoy, C A; Valiente, M; Pons, R; Montalvo, G

2015-07-01

With the increasing interest in natural formulations for drug administration and functional foods, it is desirable a good knowledge of the phase behavior of lecithin/fatty acid formulations. Phase structure and properties of ternary lecithin/fatty acids/water systems are studied at 37°C, making emphasis in regions with relatively low water and fatty acid content. The effect of fatty acid saturation degree on the phase microstructure is studied by comparing a fully saturated (palmitic acid, C16:0), monounsaturated (oleic acid, C18:1), and diunsaturated (linoleic acid, C18:2) fatty acids. Phase determinations are based on a combination of polarized light microscopy and small-angle X-ray scattering measurements. Interestingly, unsaturated (oleic acid and linoleic acid) fatty acid destabilizes the lamellar bilayer. Slight differences are observed between the phase diagrams produced by the unsaturated ones: small lamellar, medium cubic and large hexagonal regions. A narrow isotropic fluid region also appears on the lecithin-fatty acid axis, up to 8wt% water. In contrast, a marked difference in phase microsctructure was observed between unsaturated and saturated systems in which the cubic and isotropic fluid phases are not formed. These differences are, probably, a consequence of the high Krafft point of the C16 saturated chains that imply rather rigid chains. However, unsaturated fatty acids result in more flexible tails. The frequent presence of, at least, one unsaturated chain in phospholipids makes it very likely a better mixing situation than in the case of more rigid chains. This swelling potential favors the formation of reverse hexagonal, cubic, and micellar phases. Both unsaturated fatty acid systems evolve by aging, with a reduction of the extension of reverse hexagonal phase and migration of the cubic phase to lower fatty acid and water contents. The kinetic stability of the systems seems to be controlled by the unsaturation of fatty acids. Copyright © 2015 Elsevier B.V. All rights reserved.

Ground-state ordering of the J1-J2 model on the simple cubic and body-centered cubic lattices

NASA Astrophysics Data System (ADS)

Farnell, D. J. J.; Götze, O.; Richter, J.

2016-06-01

The J1-J2 Heisenberg model is a "canonical" model in the field of quantum magnetism in order to study the interplay between frustration and quantum fluctuations as well as quantum phase transitions driven by frustration. Here we apply the coupled cluster method (CCM) to study the spin-half J1-J2 model with antiferromagnetic nearest-neighbor bonds J1>0 and next-nearest-neighbor bonds J2>0 for the simple cubic (sc) and body-centered cubic (bcc) lattices. In particular, we wish to study the ground-state ordering of these systems as a function of the frustration parameter p =z2J2/z1J1 , where z1 (z2) is the number of nearest (next-nearest) neighbors. We wish to determine the positions of the phase transitions using the CCM and we aim to resolve the nature of the phase transition points. We consider the ground-state energy, order parameters, spin-spin correlation functions, as well as the spin stiffness in order to determine the ground-state phase diagrams of these models. We find a direct first-order phase transition at a value of p =0.528 from a state of nearest-neighbor Néel order to next-nearest-neighbor Néel order for the bcc lattice. For the sc lattice the situation is more subtle. CCM results for the energy, the order parameter, the spin-spin correlation functions, and the spin stiffness indicate that there is no direct first-order transition between ground-state phases with magnetic long-range order, rather it is more likely that two phases with antiferromagnetic long range are separated by a narrow region of a spin-liquid-like quantum phase around p =0.55 . Thus the strong frustration present in the J1-J2 Heisenberg model on the sc lattice may open a window for an unconventional quantum ground state in this three-dimensional spin model.

Assessment of undiscovered oil and gas resources in the Eagle Ford Group and associated Cenomanian–Turonian Strata, U.S. Gulf Coast, Texas, 2018

USGS Publications Warehouse

Whidden, Katherine J.; Pitman, Janet K.; Pearson, Ofori N.; Paxton, Stanley T.; Kinney, Scott A.; Gianoutsos, Nicholas J.; Schenk, Christopher J.; Leathers-Miller, Heidi M.; Birdwell, Justin E.; Brownfield, Michael E.; Burke, Lauri A.; Dubiel, Russell F.; French, Katherine L.; Gaswirth, Stephanie B.; Haines, Seth S.; Le, Phuong A.; Marra, Kristen R.; Mercier, Tracey J.; Tennyson, Marilyn E.; Woodall, Cheryl A.

2018-06-22

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 8.5 billion barrels of oil and 66 trillion cubic feet of gas in continuous accumulations in the Upper Cretaceous Eagle Ford Group and associated Cenomanian–Turonian strata in onshore lands of the U.S. Gulf Coast region, Texas.

Mississippi forest industry

Treesearch

Dwane D. Van Hooser

1968-01-01

Nearly 402 million cubic feet of industrial roundwood were harvested in Mississippi in 1966. This was the largest harvest in a decade. Nearly three-fifths was softwood-mainly pine. Altogether, 305 million cubic feet were processed by the State's forest industries. Some 123 million cubic feet were shipped to surrounding States, while 26 million cubic feet were...

Solving Cubic Equations by Polynomial Decomposition

ERIC Educational Resources Information Center

Kulkarni, Raghavendra G.

2011-01-01

Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…

Semiconducting cubic titanium nitride in the Th 3 P 4 structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhadram, Venkata S.; Liu, Hanyu; Xu, Enshi

We report the discovery of a long-sought-after phase of titanium nitride with stoichiometry Ti 3 N 4 using diamond anvil cell experiments combined with in situ high-resolution x-ray diffraction and Raman spectroscopy techniques, supported by ab initio calculations. Ti 3 N 4 crystallizes in the cubic Th 3 P 4 structure [space group I ¯ 4 3 d (220)] from a mixture of TiN and N 2 above ≈ 75 GPa and ≈ 2400 K. The density ( ≈ 5.22 g/cc) and bulk modulus ( K 0 = 290 GPa) of cubic- Ti 3 N 4 ( c - Timore » 3 N 4 ) at 1 atm, estimated from the pressure-volume equation of state, are comparable to rocksalt TiN. Ab initio calculations based on the GW approximation and using hybrid functionals indicate that c - Ti 3 N 4 is a semiconductor with a direct band gap between 0.8 and 0.9 eV, which is larger than the previously predicted values. The c - Ti 3 N 4 phase is not recoverable to ambient pressure due to dynamic instabilities, but recovery of Ti 3 N 4 in the defect rocksalt (or related) structure may be feasible.« less

Analysis of pulsed-neutron powder diffraction patterns of the icosahedral quasicrystals Pd3Siu and AlCuLiMg (three alloys) as twinned cubic crystals with large units.

PubMed Central

Pauling, L

1991-01-01

The low-Q peaks on three pulsed-neutron powder patterns (total, U differential, and Pd differential) of the icosahedral quasicrystal Pd3SiU have been indexed on the basis of an assumed cubic structure of the crystals that by icosahedral twinning form the quasicrystal. The primitive unit cube is found to have edge length 56.20 A and to contain approximately 12,100 atoms. Similar analyses of pulsed-neutron patterns of Al55Cu10Li35, Al55Cu10Li30Mg5, and Al510Cu125Li235Mg130 give values of the cube edge length 58.3, 58.5, and 58.4 A, respectively, with approximately 11,650 atoms in the unit cube. It is suggested that the unit contains eight complexes in the beta-W positions, plus some small interstitial groups of atoms, with each complex consisting of a centered icosahedron of 13 clusters, each of 116 atoms with the icosahedral structure found in the body-centered cubic crystal Mg32(Al,Zn)49. PMID:11607201

Analysis of pulsed-neutron powder diffraction patterns of the icosahedral quasicrystals Pd3Siu and AlCuLiMg (three alloys) as twinned cubic crystals with large units.

PubMed

Pauling, L

1991-08-01

The low-Q peaks on three pulsed-neutron powder patterns (total, U differential, and Pd differential) of the icosahedral quasicrystal Pd3SiU have been indexed on the basis of an assumed cubic structure of the crystals that by icosahedral twinning form the quasicrystal. The primitive unit cube is found to have edge length 56.20 A and to contain approximately 12,100 atoms. Similar analyses of pulsed-neutron patterns of Al55Cu10Li35, Al55Cu10Li30Mg5, and Al510Cu125Li235Mg130 give values of the cube edge length 58.3, 58.5, and 58.4 A, respectively, with approximately 11,650 atoms in the unit cube. It is suggested that the unit contains eight complexes in the beta-W positions, plus some small interstitial groups of atoms, with each complex consisting of a centered icosahedron of 13 clusters, each of 116 atoms with the icosahedral structure found in the body-centered cubic crystal Mg32(Al,Zn)49.

Structure Evolution of BaTiO3 on Co Doping: X-ray diffraction and Raman study

NASA Astrophysics Data System (ADS)

Mansuri, Amantulla; Mishra, Ashutosh

2016-10-01

In the present study, we have synthesize polycrystalline samples of BaTi1-xCoxO3 (x = 0, 0.05 and 0.1) with standard solid state reaction technique. The obtained samples are characterized by X-ray diffraction (XRD) and Raman spectroscopy. The detail structural analysis has been performed by Rietveld refinement using Fullprof program. The structural analysis reveal the samples are chemical pure and crystallize in tetragonal phase with space group Pm3m. We observe an increase in lattice parameters which results due to substitution of Co2+ with large ionic radii (0.9) for smaller ionic radii (0.6) Ti4+. Moreover peak at 45.5° shift to 45° on Co doping, which is due to structure phase transition from tetragonal to cubic. Raman study infers that the intensity of characteristic peaks decreases and linewidth increases with Co doping. The bands linked with the tetragonal structure (307 cm1) decreased due to the tetragonal-towards-cubic phase transition with Co doping. Our structural study reveals the expansion of BTO unit cell and tetragonal-to-cubic phase transformation takes place, results from different characterization techniques are conclusive and show structural evolution with Co doping.

The crystal structure and morphology of NiO-YSZ composite that prepared from local zircon concentrate of Bangka Island

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahmawati, F., E-mail: fitria@mipa.uns.ac.id; Apriyani, K.; Heraldy, E.

2016-03-29

In order to increase the economic value of local zircon concentrate from Bangka Island, NiO-YSZ was synthesized from Zirconia, ZrO{sub 2} that was prepared from local zircon concentrate. The NiO-YSZ composite was synthesized by solid state reaction method. XRD analysis equipped with Le Bail refinement was carried out to analyze the crystal structure and cell parameters of the prepared materials. The result showed that zirconia was crystallized in tetragonal structure with a space group of P42/NMC. Yttria-Stabilized-Zirconia (YSZ) was prepared by doping 8% mol yttrium oxide into zirconia and then sintered at 1250°C for 3 hours. Doping of 8% molmore » Yttria allowed phase transformation of zirconia from tetragonal into the cubic structure. Meanwhile, the composite of NiO-YSZ consists of two crystalline phases, i.e. the NiO with cubic structure and the YSZ with cubic structure. SEM analysis of the prepared materials shows that the addition of NiO into YSZ allows the morphology to become more roughness with larger grain size.« less

Three-body spectrum in a finite volume: The role of cubic symmetry

DOE PAGES

Doring, M.; Hammer, H. -W.; Mai, M.; ...

2018-06-15

The three-particle quantization condition is partially diagonalized in the center-of-mass frame by using cubic symmetry on the lattice. To this end, instead of spherical harmonics, the kernel of the Bethe-Salpeter equation for particle-dimer scattering is expanded in the basis functions of different irreducible representations of the octahedral group. Such a projection is of particular importance for the three-body problem in the finite volume due to the occurrence of three-body singularities above breakup. Additionally, we study the numerical solution and properties of such a projected quantization condition in a simple model. It is shown that, for large volumes, these solutions allowmore » for an instructive interpretation of the energy eigenvalues in terms of bound and scattering states.« less

Three-body spectrum in a finite volume: The role of cubic symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doring, M.; Hammer, H. -W.; Mai, M.

The three-particle quantization condition is partially diagonalized in the center-of-mass frame by using cubic symmetry on the lattice. To this end, instead of spherical harmonics, the kernel of the Bethe-Salpeter equation for particle-dimer scattering is expanded in the basis functions of different irreducible representations of the octahedral group. Such a projection is of particular importance for the three-body problem in the finite volume due to the occurrence of three-body singularities above breakup. Additionally, we study the numerical solution and properties of such a projected quantization condition in a simple model. It is shown that, for large volumes, these solutions allowmore » for an instructive interpretation of the energy eigenvalues in terms of bound and scattering states.« less

Surface fitting three-dimensional bodies

NASA Technical Reports Server (NTRS)

Dejarnette, F. R.

1974-01-01

The geometry of general three-dimensional bodies is generated from coordinates of points in several cross sections. Since these points may not be smooth, they are divided into segments and general conic sections are curve fit in a least-squares sense to each segment of a cross section. The conic sections are then blended in the longitudinal direction by fitting parametric cubic-spline curves through coordinate points which define the conic sections in the cross-sectional planes. Both the cross-sectional and longitudinal curves may be modified by specifying particular segments as straight lines and slopes at selected points. Slopes may be continuous or discontinuous and finite or infinite. After a satisfactory surface fit has been obtained, cards may be punched with the data necessary to form a geometry subroutine package for use in other computer programs. At any position on the body, coordinates, slopes and second partial derivatives are calculated. The method is applied to a blunted 70 deg delta wing, and it was found to generate the geometry very well.

Random regression analyses using B-spline functions to model growth of Nellore cattle.

PubMed

Boligon, A A; Mercadante, M E Z; Lôbo, R B; Baldi, F; Albuquerque, L G

2012-02-01

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.

Large springs of east Tennessee

USGS Publications Warehouse

Sun, Pao-chang P.; Criner, J.H.; Poole, J.L.

1963-01-01

Springs constitute an important source of water in east Tennessee, and many individual springs are capable of supplying the large quantities needed for municipal and industrial supplies. Most of the springs in east Tennessee issue from solution openings and fractured and faulted zones in limestone and dolomite of the Knox Group, Chickamauga Limestone, and Conasauga Group. The ability of these rocks to yield a sustained flow of water to springs is dependent on a system of interconnected openings through which water can infiltrate from the land surface and move to points of natural discharge. Ninety springs were selected for detailed study, and 84 of these are analyzed in terms of magnitude and variability of discharge. Of the 84 springs analyzed, 4 flow at an average rate of 10 to 100 cfs (cubic feet per second), 62 at an average rate of 1 to 10 cfs, and 18 at an average rate of 1 cfs or less. Of the 90 springs, 75 are variable in their discharge; that is, the ratio of their fluctuations to their average discharges exceeds 100 percent. Mathematical analysis of the flow recession curve of Mill Spring near Jefferson City shows that the hydrologic system contributing to the flow of the spring has an effective capacity of about 70 million cubic feet of water. The rate of depletion of this volume of water, in the absence of significant precipitation, averages 0.0056 cfs per day between the time when the hydrologic system is full and the time when the spring ceases to flow. From such a curve it is possible to determine at any time the residual volume of water remaining in the system and the expected rate of decrease in discharge from that time to cessation of flow. Correlation of discharge measurements of 22 springs with those of Mill Spring shows that rough approximations of discharge can be projected for springs for which few measurements are available. Seventeen of the springs analyzed in this manner show good correlation with Mill Spring: that is, their coefficients of correlation were 0.70 or better as compared with a perfect correlation factor of 1.00.

Sheet-like assemblies of spherical particles with point-symmetrical patches.

PubMed

Mani, Ethayaraja; Sanz, Eduardo; Roy, Soumyajit; Dijkstra, Marjolein; Groenewold, Jan; Kegel, Willem K

2012-04-14

We report a computational study on the spontaneous self-assembly of spherical particles into two-dimensional crystals. The experimental observation of such structures stabilized by spherical objects appeared paradoxical so far. We implement patchy interactions with the patches point-symmetrically (icosahedral and cubic) arranged on the surface of the particle. In these conditions, preference for self-assembly into sheet-like structures is observed. We explain our findings in terms of the inherent symmetry of the patches and the competition between binding energy and vibrational entropy. The simulation results explain why hollow spherical shells observed in some Keplerate-type polyoxometalates (POM) appear. Our results also provide an explanation for the experimentally observed layer-by-layer growth of apoferritin--a quasi-spherical protein.

Basin boundaries and focal points in a map coming from Bairstow's method.

PubMed

Gardini, Laura; Bischi, Gian-Italo; Fournier-Prunaret, Daniele

1999-06-01

This paper is devoted to the study of the global dynamical properties of a two-dimensional noninvertible map, with a denominator which can vanish, obtained by applying Bairstow's method to a cubic polynomial. It is shown that the complicated structure of the basins of attraction of the fixed points is due to the existence of singularities such as sets of nondefinition, focal points, and prefocal curves, which are specific to maps with a vanishing denominator, and have been recently introduced in the literature. Some global bifurcations that change the qualitative structure of the basin boundaries, are explained in terms of contacts among these singularities. The techniques used in this paper put in evidence some new dynamic behaviors and bifurcations, which are peculiar of maps with denominator; hence they can be applied to the analysis of other classes of maps coming from iterative algorithms (based on Newton's method, or others). (c) 1999 American Institute of Physics.

Surface modeling method for aircraft engine blades by using speckle patterns based on the virtual stereo vision system

NASA Astrophysics Data System (ADS)

Yu, Zhijing; Ma, Kai; Wang, Zhijun; Wu, Jun; Wang, Tao; Zhuge, Jingchang

2018-03-01

A blade is one of the most important components of an aircraft engine. Due to its high manufacturing costs, it is indispensable to come up with methods for repairing damaged blades. In order to obtain a surface model of the blades, this paper proposes a modeling method by using speckle patterns based on the virtual stereo vision system. Firstly, blades are sprayed evenly creating random speckle patterns and point clouds from blade surfaces can be calculated by using speckle patterns based on the virtual stereo vision system. Secondly, boundary points are obtained in the way of varied step lengths according to curvature and are fitted to get a blade surface envelope with a cubic B-spline curve. Finally, the surface model of blades is established with the envelope curves and the point clouds. Experimental results show that the surface model of aircraft engine blades is fair and accurate.

46 CFR 181.410 - Fixed gas fire extinguishing systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... less than 170 cubic meters (6000 cubic feet), release of an extinguishing agent into a space must... unoccupied space of less than 170 cubic meters (6,000 cubic feet) may have the storage cylinders located... between 16,550 and 19,300 kPa (2,400 and 2,800 psi) must be installed in the distribution manifold to...

40 CFR 60.1795 - May I conduct stack testing less often?

Code of Federal Regulations, 2010 CFR

2010-07-01

... dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter... meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry...

40 CFR 60.1795 - May I conduct stack testing less often?

Code of Federal Regulations, 2012 CFR

2012-07-01

... dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter... meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry...

40 CFR 62.15250 - May I conduct stack testing less often?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for Class II units, for 2 consecutive years. In this case, you may choose... per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic...

40 CFR 60.1795 - May I conduct stack testing less often?

Code of Federal Regulations, 2014 CFR

2014-07-01

... dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter... meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry...

40 CFR 62.15250 - May I conduct stack testing less often?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for Class II units, for 2 consecutive years. In this case, you may choose... per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic...

40 CFR 62.15250 - May I conduct stack testing less often?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 15 nanograms per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic meter (total mass) for Class II units, for 2 consecutive years. In this case, you may choose... per dry standard cubic meter (total mass) for Class I units, or 30 nanograms per dry standard cubic...

Assessment of Non-Traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities

DTIC Science & Technology

2016-03-01

Assessment of Non-traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities Distribution Statement A. Approved for pubic...cubic meter (m 3 ) cubic foot (ft 3 ) 2.831 685 × 10 –2 cubic meter (m 3 ) Mass /Density pound (lb) 4.535 924 × 10 –1 kilogram (kg) unified...atomic mass unit (amu) 1.660 539 × 10 –27 kilogram (kg) pound- mass per cubic foot (lb ft –3 ) 1.601 846 × 10 1 kilogram per cubic meter (kg m –3

Subalgebras of BCK/BCI-Algebras Based on Cubic Soft Sets

PubMed Central

Muhiuddin, G.; Jun, Young Bae

2014-01-01

Operations of cubic soft sets including “AND” operation and “OR” operation based on P-orders and R-orders are introduced and some related properties are investigated. An example is presented to show that the R-union of two internal cubic soft sets might not be internal. A sufficient condition is provided, which ensure that the R-union of two internal cubic soft sets is also internal. Moreover, some properties of cubic soft subalgebras of BCK/BCI-algebras based on a given parameter are discussed. PMID:24895652

Incompressible material point method for free surface flow

NASA Astrophysics Data System (ADS)

Zhang, Fan; Zhang, Xiong; Sze, Kam Yim; Lian, Yanping; Liu, Yan

2017-02-01

To overcome the shortcomings of the weakly compressible material point method (WCMPM) for modeling the free surface flow problems, an incompressible material point method (iMPM) is proposed based on operator splitting technique which splits the solution of momentum equation into two steps. An intermediate velocity field is first obtained by solving the momentum equations ignoring the pressure gradient term, and then the intermediate velocity field is corrected by the pressure term to obtain a divergence-free velocity field. A level set function which represents the signed distance to free surface is used to track the free surface and apply the pressure boundary conditions. Moreover, an hourglass damping is introduced to suppress the spurious velocity modes which are caused by the discretization of the cell center velocity divergence from the grid vertexes velocities when solving pressure Poisson equations. Numerical examples including dam break, oscillation of a cubic liquid drop and a droplet impact into deep pool show that the proposed incompressible material point method is much more accurate and efficient than the weakly compressible material point method in solving free surface flow problems.

The computation of all plane/surface intersections for CAD/CAM applications

NASA Technical Reports Server (NTRS)

Hoitsma, D. H., Jr.; Roche, M.

1984-01-01

The problem of the computation and display of all intersections of a given plane with a rational bicubic surface patch for use on an interactive CAD/CAM system is examined. The general problem of calculating all intersections of a plane and a surface consisting of rational bicubic patches is reduced to the case of a single generic patch by applying a rejection algorithm which excludes all patches that do not intersect the plane. For each pertinent patch the algorithm presented computed the intersection curves by locating an initial point on each curve, and computes successive points on the curve using a tolerance step equation. A single cubic equation solver is used to compute the initial curve points lying on the boundary of a surface patch, and the method of resultants as applied to curve theory is used to determine critical points which, in turn, are used to locate initial points that lie on intersection curves which are in the interior of the patch. Examples are given to illustrate the ability of this algorithm to produce all intersection curves.

Extensions of D-optimal Minimal Designs for Symmetric Mixture Models

PubMed Central

Raghavarao, Damaraju; Chervoneva, Inna

2017-01-01

The purpose of mixture experiments is to explore the optimum blends of mixture components, which will provide desirable response characteristics in finished products. D-optimal minimal designs have been considered for a variety of mixture models, including Scheffé's linear, quadratic, and cubic models. Usually, these D-optimal designs are minimally supported since they have just as many design points as the number of parameters. Thus, they lack the degrees of freedom to perform the Lack of Fit tests. Also, the majority of the design points in D-optimal minimal designs are on the boundary: vertices, edges, or faces of the design simplex. In This Paper, Extensions Of The D-Optimal Minimal Designs Are Developed For A General Mixture Model To Allow Additional Interior Points In The Design Space To Enable Prediction Of The Entire Response Surface Also a new strategy for adding multiple interior points for symmetric mixture models is proposed. We compare the proposed designs with Cornell (1986) two ten-point designs for the Lack of Fit test by simulations. PMID:29081574

Availability of water from the Outwash Aquifer, Marion County, Indiana

USGS Publications Warehouse

Smith, B.S.

1983-01-01

The outwash aquifer in Marion County, Indiana is a continuous, unconfined sand and gravel deposit containing isolated boulder, till, silt, and clay deposits along the White River, Fall Creek, and Eagle Creek. Flow in the aquifer is from the boundaries of the aquifer with the Tipton till plain toward the streams and major pumping centers in the aquifer. A two-dimensional, finite-difference model of the outwash aquifer was calibrated to water levels of October 6 to 10, 1980 and used to estimate availability of water in the aquifer. A drawdown limit of 50-percent saturated thickness applied to 78 simulated-pumping wells assumed to be 1 foot in diameter produced 97 cubic feet per second from the outwash aquifer. Streamflow reductions caused by 97 cubic feet per second simulated pumpage and constant-flux boundaries were estimated to be 85 cubic feet per second in the White River and 12 cubic feet per second in Fall Creek. In comparison, the 7-day, 10-year low flows were 83 cubic feet per second in the White River near Nora and 23 cubic feet per second in Fall Creek at Millersville. Simulated pumpage of 115 cubic feet per second and constant-flux boundaries produced streamflow reductions of 101 cubic feet per second on the White River and 13 cubic feet per second on Fall Creek. (USGS)

36 CFR 1254.94 - What must my request include?

Code of Federal Regulations, 2010 CFR

2010-07-01

... includes the following elements: (1) Record group number or agency of origin or, for donated historical... volume in number of pages or cubic feet. (b) The estimated amount of time (work-days) that the microfilm... who would require training (see § 1254.108(b)). (c) The number and a description of the equipment that...

Mississippi's timber industry - an assessment of timber product output and use, 1995

Treesearch

Daniel P. Stratton; Michael Howell; Randal Romedy

1998-01-01

In 1995, roundwood output from Mississippi's forests totaled 1.0 billion cubic feet. Mill byproducts generated from primary manufacturers was 357 million cubic feet. Almost all plant residue was used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 493 million cubic feet; pulpwood ranked second at 454 million cubic feet; veneer...

Changes in Florida's industrial roundwood products output, 1987-1989

Treesearch

Edgar L. Davenport

1991-01-01

Nearly 483 million cubic feet of industrial roundwood products were harvested from Florida's forests during 1989, approximately 3 million cubic feet more than in 1987. Pulpwood accounted for 61 percent and saw logs 29 percent of the total roundwood production. Output of byproducts dropped from 170 million cubic feet in 1987 to 161 million cubic feet in 1989. Only...

Arkansas's timber industry-an assessment of timber product output and use, 2005

Treesearch

James W. Bentley; Michael Howell; Tony G. Johnson

2008-01-01

In 2005, roundwood output from Arkansas's forests totaled 749 million cubic feet. Mill byproducts generated from primary manufacturers were 354 million cubic feet. Almost all plant residues were used, primarily for fuel and fiber products. Saw logs were the leading roundwood product at 390 million cubic feet; pulpwood ranked second at 235 million cubic feet; and...

Arkansas' timber industry - an assessment of timber product output and use, 1999

Treesearch

James W. Bentley; Tony G. Johnson; Michael Howell

2002-01-01

In 1999, roundwood output from Arkansas' forests totaled 692 million cubic feet. Mill byproducts generated from primary manufacturers were 290 million cubic feet. Almost all plant residues were used, primarily for fuel and fiber products. Saw logs were the leading roundwood product at 320 million cubic feet; pulpwood ranked second at 285 million cubic feet; veneer...

Arkansas' timber industry - an assessment of timber product output and use, 1996

Treesearch

Michael Howell; Robert Levins

1998-01-01

In 1996, roundwood output from Arkansas forests totaled 636 million cubic feet. Mill byproducts generated from primary manufacturers was 286 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 315 million cubic feet; pulpwood ranked second at 242 million cubic feet; veneer logs...

Oklahoma's timber industry - an assessment of timber product output and use, 1996

Treesearch

Michael Howell; Tony G. Johnson

1998-01-01

In 1996, roundwood output from Oklahoma's forests totaled 113 million cubic feet. Mill byproducts generated from primary manufacturers was 42 million cubic feet. Almost all plant residue was used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 54 million cubic feet; pulpwood ranked second at 40 million cubic feet. There were...

Alabama's timber industry - an assessment of timber product output and use, 1997

Treesearch

Michael Howell; Jim R. Gober; J. Stephen Nix

1999-01-01

In 1997, roundwood output from Alabama's forests totaled 1.3 billion cubic feet. Mill byproducts generated from primary manufacturers amounted to 477 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Pulpwood was the leading roundwood product at 765 million cubic feet; saw logs ranked second at 450 million cubic feet;...

First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements

NASA Astrophysics Data System (ADS)

Li, Yubo; Wang, Pengtao; Hua, Fei; Zhan, Shijie; Wang, Xiaozhi; Luo, Jikui; Yang, Hangsheng

2018-03-01

Electronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA→B) or the N (IIA→N) atom. For IIA→B, a shallow accept level degenerated into valence band (VB); while for IIA→N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe→N and IIMg→N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants' radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant.

Identification and properties of the non-cubic phases of Mg 2Pb

DOE PAGES

Li, Yuwei; Bian, Guang; Singh, David J.

2016-12-20

Mg 2Pb occurs in the cubic fluorite structure and is a semimetal with a band structure strongly affected by spin-orbit interaction on the Pb p states. Its properties are therefore of interest in the context of topological materials. In addition a different phase of Mg 2Pb was experimentally reported, but its crystal structure and properties remain unknown. Here we determine the structure of this phase using ab initio evolutionary methods and report its properties. The energy of one tetragonal phase, space group P4/ nmm, is 2 meV per atom higher than that of the ground state structure supporting the experimentalmore » observation. We find this tetragonal phase to be a compenstated anisotropic metal with strong spin orbit effects. As a result, many other metastable structures have also been identified, especially one orthorhombic structure, space group Pnma, of which energy is 17 meV per atom higher than that of ground state structure and which perhaps could be the phase that was reported based on similarity of lattice parameters.« less

Polarization-free integrated gallium-nitride photonics

PubMed Central

Bayram, C.; Liu, R.

2017-01-01

Gallium Nitride (GaN) materials are the backbone of emerging solid state lighting. To date, GaN research has been primarily focused on hexagonal phase devices due to the natural crystallization. This approach limits the output power and efficiency of LEDs, particularly in the green spectrum. However, GaN can also be engineered to be in cubic phase. Cubic GaN has a lower bandgap (~200 meV) than hexagonal GaN that enables green LEDs much easily. Besides, cubic GaN has more isotropic properties (smaller effective masses, higher carrier mobility, higher doping efficiency, and higher optical gain than hexagonal GaN), and cleavage planes. Due to phase instability, however, cubic phase materials and devices have remained mostly unexplored. Here we review a new method of cubic phase GaN generation: Hexagonal-to-cubic phase transition, based on novel nano-patterning. We report a new crystallographic modelling of this hexagonal-to-cubic phase transition and systematically study the effects of nano-patterning on the GaN phase transition via transmission electron microscopy and electron backscatter diffraction experiments. In summary, silicon-integrated cubic phase GaN light emitters offer a unique opportunity for exploration in next generation photonics. PMID:29307953

Rheology of Ultraswollen Bicontinuous Lipidic Cubic Phases.

PubMed

Speziale, Chiara; Ghanbari, Reza; Mezzenga, Raffaele

2018-05-01

Rheological studies of liquid crystalline systems based on monopalmitolein and 5 or 8% of 1,2 distearoylphosphatidylglycerol are reported. Such cubic phases have been shown to possess unusually large water channels because of their ability of accommodating up to 80 wt % of water, a feature that renders these systems suitable for crystallizing membrane proteins with large extracellular domains. Their mechanical properties are supposed to be substantially different from those of traditional cubic phases. Rheological measurements were carried out on cubic phases of both Pn3 m and Ia3 d symmetries. It was verified that these ultraswollen cubic phases are less rigid than the normal cubic phases, with the Pn3 m being softer that the Ia3 d ones. Furthermore, for the Pn3 m case, the longest relaxation time is shown to decrease logarithmically with increasing surface area per unit volume, proving the critical role of the density of interfaces in establishing the macroscopic viscoelastic properties of the bicontinuous cubic phases.

Using SANS with Contrast-Matched Lipid Bicontinuous Cubic Phases To Determine the Location of Encapsulated Peptides, Proteins, and Other Biomolecules.

PubMed

van 't Hag, Leonie; de Campo, Liliana; Garvey, Christopher J; Feast, George C; Leung, Anna E; Yepuri, Nageshwar Rao; Knott, Robert; Greaves, Tamar L; Tran, Nhiem; Gras, Sally L; Drummond, Calum J; Conn, Charlotte E

2016-07-21

An understanding of the location of peptides, proteins, and other biomolecules within the bicontinuous cubic phase is crucial for understanding and evolving biological and biomedical applications of these hybrid biomolecule-lipid materials, including during in meso crystallization and drug delivery. While theoretical modeling has indicated that proteins and additive lipids might phase separate locally and adopt a preferred location in the cubic phase, this has never been experimentally confirmed. We have demonstrated that perfectly contrast-matched cubic phases in D2O can be studied using small-angle neutron scattering by mixing fully deuterated and hydrogenated lipid at an appropriate ratio. The model transmembrane peptide WALP21 showed no preferential location in the membrane of the diamond cubic phase of phytanoyl monoethanolamide and was not incorporated in the gyroid cubic phase. While deuteration had a small effect on the phase behavior of the cubic phase forming lipids, the changes did not significantly affect our results.

Preparation of Zr(Mo,W)2O8 with a larger negative thermal expansion by controlling the thermal decomposition of Zr(Mo,W)2(OH,Cl)2∙2H2O.

PubMed

Petrushina, Mariya Yu; Dedova, Elena S; Filatov, Eugeny Yu; Plyusnin, Pavel E; Korenev, Sergei V; Kulkov, Sergei N; Derevyannikova, Elizaveta A; Sharafutdinov, Marat R; Gubanov, Alexander I

2018-03-28

Solid solutions of Zr(Mo,W) 2 O 7 (OH,Cl) 2 ∙2H 2 O with a preset ratio of components were prepared by a hydrothermal method. The chemical composition of the solutions was determined by energy dispersive X-ray spectroscopy (EDX). For all the samples of ZrMo x W 2-x O 7 (OH,Cl) 2 ∙2H 2 O (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0), TGA and in situ powder X-ray diffraction (PXRD) studies (300-1100 K) were conducted. For each case, the boundaries of the transformations were determined: Zr(Mo,W) 2 O 7 (OH,Cl) 2 ∙2H 2 O → orthorhombic-ZrMo x W 2-x O 8 (425-525 K), orthorhombic-ZrMo x W 2-x O 8  → cubic-ZrMo x W 2-x O 8 (700-850 K), cubic-ZrMo x W 2-x O 8  → trigonal-ZrMo x W 2-x O 8 (800-1050 K for x > 1) and cubic-ZrMo x W 2-x O 8  → oxides (1000-1075 K for x ≤ 1). The cell parameters of the disordered cubic-ZrMo x W 2-x O 8 (space group Pa-3) were measured within 300-900 K, and the thermal expansion coefficients were calculated: -3.5∙10 -6  - -4.5∙10 -6  K -1 . For the ordered ZrMo 1.8 W 0.2 O 8 (space group P2 1 3), a negative thermal expansion (NTE) coefficient -9.6∙10 -6  K -1 (300-400 K) was calculated. Orthorhombic-ZrW2O 8 is formed upon the decomposition of ZrW 2 O 7 (OH,Cl) 2 ∙2H 2 O within 500-800 K.

Interconversion of large packets and small groups of cells of Micrococcus rubens: dependence upon magnesium and phosphate.

PubMed Central

Yamada, M; Koyama, T; Matsuhashi, M

1977-01-01

Micrococcus rubens, a gram-positive occus, usually forms large, cubic packets of more than 500 cells that are regularly arranged in three-dimensional cell groups. In medium with extremely low concentration of Mg2+ and phosphate, in which the cells can only grow on a agar surface, it formed small groups of 2 to 20 cells. Irregularly arraged cell groups of intermediated size were obtained in culture media containing intermediated concentrations of Mg2+ and phosphate. Mutants that formed irregular cell groups of intermediate size under normal culture conditions were also obtained. Images PMID:845123

X-Ray Diffraction (XRD) Characterization Methods for Sigma=3 Twin Defects in Cubic Semiconductor (100) Wafers

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Kim, Hyun Jung (Inventor); Skuza, Jonathan R. (Inventor); Lee, Kunik (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor)

2017-01-01

An X-ray defraction (XRD) characterization method for sigma=3 twin defects in cubic semiconductor (100) wafers includes a concentration measurement method and a wafer mapping method for any cubic tetrahedral semiconductor wafers including GaAs (100) wafers and Si (100) wafers. The methods use the cubic semiconductor's (004) pole figure in order to detect sigma=3/{111} twin defects. The XRD methods are applicable to any (100) wafers of tetrahedral cubic semiconductors in the diamond structure (Si, Ge, C) and cubic zinc-blend structure (InP, InGaAs, CdTe, ZnSe, and so on) with various growth methods such as Liquid Encapsulated Czochralski (LEC) growth, Molecular Beam Epitaxy (MBE), Organometallic Vapor Phase Epitaxy (OMVPE), Czochralski growth and Metal Organic Chemical Vapor Deposition (MOCVD) growth.

Performance of Statistical Temporal Downscaling Techniques of Wind Speed Data Over Aegean Sea

NASA Astrophysics Data System (ADS)

Gokhan Guler, Hasan; Baykal, Cuneyt; Ozyurt, Gulizar; Kisacik, Dogan

2016-04-01

Wind speed data is a key input for many meteorological and engineering applications. Many institutions provide wind speed data with temporal resolutions ranging from one hour to twenty four hours. Higher temporal resolution is generally required for some applications such as reliable wave hindcasting studies. One solution to generate wind data at high sampling frequencies is to use statistical downscaling techniques to interpolate values of the finer sampling intervals from the available data. In this study, the major aim is to assess temporal downscaling performance of nine statistical interpolation techniques by quantifying the inherent uncertainty due to selection of different techniques. For this purpose, hourly 10-m wind speed data taken from 227 data points over Aegean Sea between 1979 and 2010 having a spatial resolution of approximately 0.3 degrees are analyzed from the National Centers for Environmental Prediction (NCEP) The Climate Forecast System Reanalysis database. Additionally, hourly 10-m wind speed data of two in-situ measurement stations between June, 2014 and June, 2015 are considered to understand effect of dataset properties on the uncertainty generated by interpolation technique. In this study, nine statistical interpolation techniques are selected as w0 (left constant) interpolation, w6 (right constant) interpolation, averaging step function interpolation, linear interpolation, 1D Fast Fourier Transform interpolation, 2nd and 3rd degree Lagrange polynomial interpolation, cubic spline interpolation, piecewise cubic Hermite interpolating polynomials. Original data is down sampled to 6 hours (i.e. wind speeds at 0th, 6th, 12th and 18th hours of each day are selected), then 6 hourly data is temporally downscaled to hourly data (i.e. the wind speeds at each hour between the intervals are computed) using nine interpolation technique, and finally original data is compared with the temporally downscaled data. A penalty point system based on coefficient of variation root mean square error, normalized mean absolute error, and prediction skill is selected to rank nine interpolation techniques according to their performance. Thus, error originated from the temporal downscaling technique is quantified which is an important output to determine wind and wave modelling uncertainties, and the performance of these techniques are demonstrated over Aegean Sea indicating spatial trends and discussing relevance to data type (i.e. reanalysis data or in-situ measurements). Furthermore, bias introduced by the best temporal downscaling technique is discussed. Preliminary results show that overall piecewise cubic Hermite interpolating polynomials have the highest performance to temporally downscale wind speed data for both reanalysis data and in-situ measurements over Aegean Sea. However, it is observed that cubic spline interpolation performs much better along Aegean coastline where the data points are close to the land. Acknowledgement: This research was partly supported by TUBITAK Grant number 213M534 according to Turkish Russian Joint research grant with RFBR and the CoCoNET (Towards Coast to Coast Network of Marine Protected Areas Coupled by Wİnd Energy Potential) project funded by European Union FP7/2007-2013 program.

Thermal, structural, functional, optical and magnetic studies of pure and Ba doped CdO nanoparticles.

PubMed

Sivakumar, S; Venkatesan, A; Soundhirarajan, P; Khatiwada, Chandra Prasad

2015-12-05

In this research, a chemical precipitation method was used to synthesize undoped and doped cadmium oxide nanoparticles and studied by TG-DTA, XRD, FT-IR, SEM, with EDX and antibacterial activities, respectively. The melting points, thermal stability and the kinetic parameters like entropy (ΔS), enthalpy (ΔH), Gibb's energy (ΔG), activation energy (E), frequency factor (A) were evaluated from TG-DTA measurements. X-ray diffraction analysis (XRD) brought out the information about the synthesized products exist in spherical in shape with cubic structure. The functional groups and band area of the samples were established by Fourier transform infrared (FT-IR) spectroscopy. The direct and indirect band gap energy of pure and doped samples were determined by UV-Vis-DRS. The surface morphological, elemental compositions and particles sizes were evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Finally, antibacterial activities indicated the Gram-positive and Gram-negative bacteria are more active in transporter, dehydrogenize and periplasmic enzymatic activities of pure and doped samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Recipe for generating Weyl semimetals with extended topologically protected features

NASA Astrophysics Data System (ADS)

Wang, R.; Zhao, J. Z.; Jin, Y. J.; Xu, W. P.; Gan, L.-Y.; Wu, X. Z.; Xu, H.; Tong, S. Y.

2017-09-01

We present a recipe that leads to Weyl semimetals with extended topologically protected features. We show that compounds in a family that possess time-reversal symmetry and share a noncentrosymmetric cubic structure with the space group F -43 m (no. 216) host robust Weyl fermions with extended and easily measurable protected features. The candidates in this family are compounds with different chemical formulas, A B2 , ABC, AB C2 , and ABCD, and their Fermi levels are predominantly populated by nontrivial Weyl fermions. Symmetry of the system requires that the Weyl nodes with opposite chirality are well separated in momentum space. Adjacent Weyl points have the same chirality; thus these Weyl nodes would not annihilate each other with respect to lattice perturbations. As Fermi arcs and surface states connect Weyl nodes with opposite chirality, the large separation of the latter in momentum space guarantees the appearance of very long arcs and surface states. This work demonstrates that the use of system symmetry by first-principles calculations is a powerful approach for discovering new Weyl semimetals with attractive features whose protected fermions may be candidates of many applications.

Designing of skull defect implants using C1 rational cubic Bezier and offset curves

NASA Astrophysics Data System (ADS)

Mohamed, Najihah; Majid, Ahmad Abd; Piah, Abd Rahni Mt; Rajion, Zainul Ahmad

2015-05-01

Some of the reasons to construct skull implant are due to head trauma after an accident or an injury or an infection or because of tumor invasion or when autogenous bone is not suitable for replacement after a decompressive craniectomy (DC). The main objective of our study is to develop a simple method to redesign missing parts of the skull. The procedure begins with segmentation, data approximation, and estimation process of the outer wall by a C1 continuous curve. Its offset curve is used to generate the inner wall. A metaheuristic algorithm, called harmony search (HS) is a derivative-free real parameter optimization algorithm inspired from the musical improvisation process of searching for a perfect state of harmony. In this study, data approximation by a rational cubic Bézier function uses HS to optimize position of middle points and value of the weights. All the phases contribute significantly in making our proposed technique automated. Graphical examples of several postoperative skulls are displayed to show the effectiveness of our proposed method.

A novel numerical framework for self-similarity in plasticity: Wedge indentation in single crystals

NASA Astrophysics Data System (ADS)

Juul, K. J.; Niordson, C. F.; Nielsen, K. L.; Kysar, J. W.

2018-03-01

A novel numerical framework for analyzing self-similar problems in plasticity is developed and demonstrated. Self-similar problems of this kind include processes such as stationary cracks, void growth, indentation etc. The proposed technique offers a simple and efficient method for handling this class of complex problems by avoiding issues related to traditional Lagrangian procedures. Moreover, the proposed technique allows for focusing the mesh in the region of interest. In the present paper, the technique is exploited to analyze the well-known wedge indentation problem of an elastic-viscoplastic single crystal. However, the framework may be readily adapted to any constitutive law of interest. The main focus herein is the development of the self-similar framework, while the indentation study serves primarily as verification of the technique by comparing to existing numerical and analytical studies. In this study, the three most common metal crystal structures will be investigated, namely the face-centered cubic (FCC), body-centered cubic (BCC), and hexagonal close packed (HCP) crystal structures, where the stress and slip rate fields around the moving contact point singularity are presented.

Speed selection for traveling-wave solutions to the diffusion-reaction equation with cubic reaction term and Burgers nonlinear convection.

PubMed

Sabelnikov, V A; Lipatnikov, A N

2014-09-01

The problem of traveling wave (TW) speed selection for solutions to a generalized Murray-Burgers-KPP-Fisher parabolic equation with a strictly positive cubic reaction term is considered theoretically and the initial boundary value problem is numerically solved in order to support obtained analytical results. Depending on the magnitude of a parameter inherent in the reaction term (i) the term is either a concave function or a function with the inflection point and (ii) transition from pulled to pushed TW solution occurs due to interplay of two nonlinear terms; the reaction term and the Burgers convection term. Explicit pushed TW solutions are derived. It is shown that physically observable TW solutions, i.e., solutions obtained by solving the initial boundary value problem with a sufficiently steep initial condition, can be determined by seeking the TW solution characterized by the maximum decay rate at its leading edge. In the Appendix, the developed approach is applied to a non-linear diffusion-reaction equation that is widely used to model premixed turbulent combustion.

Melting curves and entropy of fusion of body-centered cubic tungsten under pressure

NASA Astrophysics Data System (ADS)

Liu, Chun-Mei; Chen, Xiang-Rong; Xu, Chao; Cai, Ling-Cang; Jing, Fu-Qian

2012-07-01

The melting curves and entropy of fusion of body-centered cubic (bcc) tungsten (W) under pressure are investigated via molecular dynamics (MD) simulations with extended Finnis-Sinclair (EFS) potential. The zero pressure melting point obtained is better than other theoretical results by MD simulations with the embedded-atom-method (EAM), Finnis-Sinclair (FS) and modified EAM potentials, and by ab initio MD simulations. Our radial distribution function and running coordination number analyses indicate that apart from the expected increase in disorder, the main change on going from solid to liquid is thus a slight decrease in coordination number. Our entropy of fusion of W during melting, ΔS, at zero pressure, 7.619 J/mol.K, is in good agreement with the experimental and other theoretical data. We found that, with the increasing pressure, the entropy of fusion ΔS decreases fast first and then oscillates with pressure; when the pressure is higher than 100 GPa, the entropy of fusion ΔS is about 6.575 ± 0.086 J/mol.K, which shows less pressure effect.

Hot-water aquifer storage: A field test

NASA Astrophysics Data System (ADS)

Parr, A. D.; Molz, F. J.; Andersen, P. F.

1980-03-01

The basic water injection cycle used in a large-scale field study of heat storage in a confined aquifer near Mobile, Alabama is described. Water was pumped from an upper semi-confined aquifer, passed through a boiler where it was heated to a temperature of about 55 C, and injected into a medium sand confined aquifer. The injection well has a 6-inch (15-cm) partially-penetrating steel screen. The top of the storage formation is about 40 meters below the surface and the formation thickness is about 21 meters. In the first cycle, after a storage period of 51 days, the injection well was pumped until the temperature of the recovered water dropped to 33 c. At that point 55,300 cubic meters of water had been withdrawn and 66 percent of the injected energy had been recovered. The recovery period for the second cycle continued until the water temperature was 27.5 C and 100,100 cubic meters of water was recovered. At the end of the cycle about 90 percent of the energy injected during the cycle had been recovered.

Cubic Interactions of Massless Bosonic Fields in Three Dimensions

NASA Astrophysics Data System (ADS)

Mkrtchyan, Karapet

2018-06-01

In this Letter, we take the first step towards construction of nontrivial Lagrangian theories of higher-spin gravity in a metriclike formulation in three dimensions. The crucial feature of a metriclike formulation is that it is known how to incorporate matter interactions into the description. We derive a complete classification of cubic interactions for arbitrary triples s1 , s2 , s3 of massless fields, which are the building blocks of any interacting theory with massless higher spins. We find that there is, at most, one vertex for any given triple of spins in 3D (with one exception, s1=s2=s3=1 , which allows for two vertices). Remarkably, there are no vertices for spin values that do not respect strict triangle inequalities and contain at least two spins greater than one. This translates into selection rules for three-point functions of higher-spin conserved currents in two dimensional conformal field theory. Furthermore, universal coupling to gravity for any spin is derived. Last, we argue that this classification persists in arbitrary Einstein backgrounds.

Louisiana’s timber industry-timber product output and use, 2013

Treesearch

James A. Gray; James W. Bentley; Jason A. Cooper; David J. Wall

2017-01-01

In 2013, processing of primary products in Louisiana mills gener-ated 206.7 million cubic feet of wood and bark residues. Coarse residues from all primary products amounted to 76.9 million cubic feet, while bark volume totaled 68.3 million cubic feet. Collective-ly, sawdust and shavings made up 30 percent of total residues, or 61.4 million cubic feet (fig. 7).

Arkansas' timber industry - an assessment of timber product output and use, 2002

Treesearch

James W. Bentley; Michael Howell; Tony G. Johnson

2005-01-01

In 2002, roundwood output from Arkansas’ forests totaled 680 million cubic feet. Mill byproducts generated from primary manufacturers were 326 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 342 million cubic feet; pulpwood ranked second at 213 million cubic feet; and veneer...

Tennessee's timber industry-an assessment of timber product output and use, 2005

Treesearch

James W. Bentley; Doug Schnabel

2007-01-01

In 2005, roundwood output from Tennessee’s forests was 325 million cubic feet. Mill byproducts generated from primary manufacturers totaled 119 million cubic feet. Seventy-three percent of the plant residues were used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 189 million cubic feet; pulpwood ranked second at 121 million cubic...

Alabama's timber industry-an assessment of timber product output and use, 2005

Treesearch

James w. Bentley; Walter E. Cartwright; Brian Hendricks

2008-01-01

In 2005, roundwood output from Alabama’s forests totaled 1.14 billion cubic feet. Mill byproducts generated from primary manufacturers amounted to 432 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Pulpwood was the leading roundwood product at 563 million cubic feet; saw logs ranked second at 425 million cubic feet;...

Changes in South Carolina's industrial timber products output, 1988

Treesearch

Edgar L. Davenport; John B. Tansey

1990-01-01

In 1988, roundwood output from South Carolina's forests amounted to 605.1 million cubic feet. Residue generated from plants in South Carolina increased to 205.9 million cubic feet and was mostly used for fiber and fuel. Pulpwood was the leading roundwood product with 283.2 million cubic feet; saw logs was next with 253.7 million cubic feet, and then veneer logs...

Oklahoma's timber industry - an assessment of timber product output and use, 2002

Treesearch

Tony G. Johnson; Michael Howell; James W. Bentley

2005-01-01

In 2002, roundwood output from Oklahoma’s forests totaled 126 million cubic feet. Mill byproducts generated from primary manufacturers totaled 50 million cubic feet. Almost all plant residue was used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 64 million cubic feet; pulpwood ranked second at 49 million cubic feet. There were...

Use of the Primitive Unit Cell in Understanding Subtle Features of the Cubic Closest-Packed Structure

ERIC Educational Resources Information Center

Hawkins, John A.; Rittenhouse, Jeffrey L.; Soper, Linda M.; Rittenhouse, Robert C.

2008-01-01

One of the most important crystal structures adopted by metals is characterized by the "abcabc"...stacking of close-packed layers. This structure is commonly referred to in textbooks as the cubic close-packed (ccp) or face-centered cubic (fcc) structure, since the entire lattice can be generated by replication of a face-centered cubic unit cell…

Oklahoma's timber industry--an assessment of timber product output and use, 2005

Treesearch

Tony G. Johnson; James W. Bentley; Michael Howell

2008-01-01

In 2005, roundwood output from Oklahoma’s forests totaled 119 million cubic feet. Mill byproducts generated from primary manufacturers totaled 54 million cubic feet. Almost all plant residue was used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 61 million cubic feet; pulpwood ranked second at 37 million cubic feet. There were...

Alabama's timber industry - An assessment of timber product output and use, 2003

Treesearch

James W. Bentley; Walter E. Cartwright

2006-01-01

In 2003, roundwood output from Alabama’s forests totaled 1.08 billion cubic feet. Mill byproducts generated from primary manufacturers amounted to 410 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Pulpwood was the leading roundwood product at 521 million cubic feet; saw logs ranked second at 404 million cubic feet;...

Use of Pom Pons to Illustrate Cubic Crystal Structures.

ERIC Educational Resources Information Center

Cady, Susan G.

1997-01-01

Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

Dolutegravir plus abacavir-lamivudine for the treatment of HIV-1 infection.

PubMed

Walmsley, Sharon L; Antela, Antonio; Clumeck, Nathan; Duiculescu, Dan; Eberhard, Andrea; Gutiérrez, Felix; Hocqueloux, Laurent; Maggiolo, Franco; Sandkovsky, Uriel; Granier, Catherine; Pappa, Keith; Wynne, Brian; Min, Sherene; Nichols, Garrett

2013-11-07

Dolutegravir (S/GSK1349572), a once-daily, unboosted integrase inhibitor, was recently approved in the United States for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in combination with other antiretroviral agents. Dolutegravir, in combination with abacavir-lamivudine, may provide a simplified regimen. We conducted a randomized, double-blind, phase 3 study involving adult participants who had not received previous therapy for HIV-1 infection and who had an HIV-1 RNA level of 1000 copies per milliliter or more. Participants were randomly assigned to dolutegravir at a dose of 50 mg plus abacavir-lamivudine once daily (DTG-ABC-3TC group) or combination therapy with efavirenz-tenofovir disoproxil fumarate (DF)-emtricitabine once daily (EFV-TDF-FTC group). The primary end point was the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter at week 48. Secondary end points included the time to viral suppression, the change from baseline in CD4+ T-cell count, safety, and viral resistance. A total of 833 participants received at least one dose of study drug. At week 48, the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter was significantly higher in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (88% vs. 81%, P=0.003), thus meeting the criterion for superiority. The DTG-ABC-3TC group had a shorter median time to viral suppression than did the EFV-TDF-FTC group (28 vs. 84 days, P<0.001), as well as greater increases in CD4+ T-cell count (267 vs. 208 per cubic millimeter, P<0.001). The proportion of participants who discontinued therapy owing to adverse events was lower in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (2% vs. 10%); rash and neuropsychiatric events (including abnormal dreams, anxiety, dizziness, and somnolence) were significantly more common in the EFV-TDF-FTC group, whereas insomnia was reported more frequently in the DTG-ABC-3TC group. No participants in the DTG-ABC-3TC group had detectable antiviral resistance; one tenofovir DF-associated mutation and four efavirenz-associated mutations were detected in participants with virologic failure in the EFV-TDF-FTC group. Dolutegravir plus abacavir-lamivudine had a better safety profile and was more effective through 48 weeks than the regimen with efavirenz-tenofovir DF-emtricitabine. (Funded by ViiV Healthcare; SINGLE ClinicalTrials.gov number, NCT01263015 .).

Proton dynamics and the phase diagram of dense water ice.

PubMed

Hernandez, J-A; Caracas, R

2018-06-07

All the different phases of water ice between 2 GPa and several megabars are based on a single body-centered cubic sub-lattice of oxygen atoms. They differ only by the behavior of the hydrogen atoms. In this study, we investigate the dynamics of the H atoms at high pressures and temperatures in water ice from first-principles molecular dynamics simulations. We provide a detailed analysis of the O-H⋯O bonding dynamics over the entire stability domain of the body-centered cubic (bcc) water ices and compute transport properties and vibrational density-of-states. We report the first ab initio evidence for a plastic phase of water and we propose a coherent phase diagram for bcc water ices compatible with the two groups of melting curves and with the multiple anomalies reported in ice VII around 15 GPa.

40 CFR Table 1a to Subpart Ec of... - Emissions Limits for Small, Medium, and Large HMIWI at Affected Facilities as Defined in § 60.50c...

Code of Federal Regulations, 2011 CFR

2011-07-01

... limits HMIWI size Small Medium Large Averaging time 1 Methodfor demonstrating compliance 2 Particulate matter Milligrams per dry standard cubic meter (grains per dry standard cubic foot) 69 (0.03) 34 (0.015.../furans (grains per billion dry standard cubic feet) or nanograms per dry standard cubic meter TEQ (grains...

40 CFR Table 1b to Subpart Ec of... - Emissions Limits for Small, Medium, and Large HMIWI at Affected Facilities as Defined in § 60.50c...

Code of Federal Regulations, 2011 CFR

2011-07-01

... HMIWI size Small Medium Large Averaging time 1 Method fordemonstrating compliance 2 Particulate matter Milligrams per dry standard cubic meter (grains per dry standard cubic foot) 66 (0.029) 22 (0.0095) 18 (0.../furans (grains per billion dry standard cubic feet) or nanograms per dry standard cubic meter TEQ (grains...

Oklahoma’s timber industry - an assessment of timber product output and use, 2009

Treesearch

Tony G. Johnson

2011-01-01

In 2009, roundwood output from Oklahoma’s forests totaled 66.3 million cubic feet. Mill byproducts generated from primary manufacturers totaled 19.2 million cubic feet. Almost all plant residues generated were used primarily for fuel and fiber products. Pulpwood was the leading roundwood product at 37.5 million cubic feet; saw logs ranked second at 25.3 million cubic...

Alabama’s timber industry - an assessment of timber product output and use, 2009

Treesearch

James W. Bentley; Tony G. Johnson; Brian Hendricks

2011-01-01

In 2009, roundwood output from Alabama’s forests totaled 803.3 million cubic feet. Mill byproducts generated from primary manufacturers amounted to 216.8 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Pulpwood was the leading roundwood product at 515.1 million cubic feet; saw logs ranked second at 228.3 million cubic feet...

Changes in output of industrial timber products in Virginia, 1976-1978

Treesearch

Richard L. Welch; Thomas R. Bellamy

1980-01-01

Almost 360 million cubic feet of industrial roundwood products were harvested from Virginia’s forest in 1978, and an estimates 137 million cubic feet of wood residues were left in the forests. Virginia shipped 41 million cubic feet of roundwood products to plants outside the State, and Virginia plants received 65 million cubic feet of out-of-state wood. Over 75 percent...

The time-dependence of the defective nature of ice Ic (cubic ice) and its implications for atmospheric science

NASA Astrophysics Data System (ADS)

Sippel, Christian; Koza, Michael M.; Hansen, Thomas C.; Kuhs, Werner F.

2010-05-01

The possible atmospheric implication of ice Ic (cubic ice) has already been suggested some time ago in the context of snow crystal formation [1]. New findings from air-borne measurements in cirrus clouds and contrails have put ice Ic into the focus of interest to understand the so-called "supersaturation puzzle" [2,3,4]. Our recent microstructural work on ice Ic [5,6] appears to be highly relevant in this context. We have found that ice Ic is characterized by a complex stacking fault pattern, which changes as a function of temperature as well as time. Indeed, from our own [7] and other group's work [8] one knows that (in contrast to earlier believe) ice Ic can form up to temperatures at least as high as 240K - thus in the relevant range for cirrus clouds. We have good preliminary evidence that the "cubicity" (which can be related to stacking fault probabilities) as well as the particle size of ice Ic are the relevant parameters for this correlation. The "cubicity" of stacking faulty ice Ic (established by diffraction) correlates nicely with the increased supersaturation at decreasing temperatures observed in cirrus clouds and contrails, a fact, which may be considered as further evidence for the presence of ice Ic. Recently, we have studied the time-dependency of the changes in both "cubicity" and particle size at various temperatures of relevance for cirrus clouds and contrails by in-situ neutron powder diffraction. The timescales over which changes occur (several to many hours) are similar to the life-time of cirrus clouds and contrails and suggest that the supersaturation situation may change within this time span in the natural environment too. Some accompanying results obtained by cryo-SEM (scanning electron microscopy) work will also be presented and suggest that stacking-faulty ice Ic has kinky surfaces providing many more active centres for heterogeneous reactions on the surface than in the usually assumed stable hexagonal form of ice Ih with its rather flat low-indexed crystal faces. [1] T Kobayashi & T Kuroda (1987) Snow Crystals. In: Morphology of Crystals (ed. I Sunagawa), Terra Scientific Publishing, Tokyo, pp.649-743. [2] RS Gao & 19 other authors (2004) Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds. Science 303, 516-520. [3] T Peter, C Marcolli, P Spichtinger, T Corti, MC Baker & T Koop (2006) When dry air is too humid. Science 314, 1399-1402. [4] JE Shilling, MA Tolbert, OB Toon, EJ Jensen, BJ Murray & AK Bertram (2006) Measurements of the vapor pressure of cubic ice and their implications for atmospheric ice clouds. Geophys.Res.Lett. 33, 026671. [5] TC Hansen, MM Koza & WF Kuhs (2008) Formation and annealing of cubic ice: I Modelling of stacking faults. J.Phys.Cond.Matt. 20, 285104. [6] TC Hansen, MM Koza, P Lindner & WF Kuhs (2008) Formation and annealing of cubic ice: II. Kinetic study. J.Phys.Cond.Matt. 20, 285105. [7] WF Kuhs, G Genov, DK Staykova & AN Salamatin, T Hansen (2004) Ice perfection and the onset of anomalous preservation of gas hydrates. Phys.Chem.Chem.Phys. 6, 4917-4920. [8] BJ Murray, DA Knopf & AK Bertram (2005) The formation of cubic ice under conditions relevant to Earth's atmosphere. Nature 434, 292-205.

Nuclear Security Summit and Workshop 2015: Preventing, Understanding and Recovering from Nuclear Accidents lessons learned from Chernobyl and Fukushima

DTIC Science & Technology

2016-09-01

10 –3 cubic meter (m 3 ) cubic foot (ft 3 ) 2.831 685 × 10 –2 cubic meter (m 3 ) Mass /Density pound (lb) 4.535 924 × 10 –1 kilogram (kg...unified atomic mass unit (amu) 1.660 539 × 10 –27 kilogram (kg) pound- mass per cubic foot (lb ft –3 ) 1.601 846 × 10 1 kilogram per cubic meter (kg m...have a controlling infleunce on the solubility of actinides and fission products, and can be harnessed for non-invasive bioremediation. In the “far

Unified structure theory of icosahedral quasicrystals: Evidence from neutron powder diffraction patterns that AlCrFeMnSi, AlCuLiMg, and TiNiFeSi icosahedral quasicrystals are twins of cubic crystals containing about 820 or 1012 atoms in a primitive unit cube

PubMed Central

Pauling, Linus

1988-01-01

A unified structure theory of icosahedral quasicrystals, combining the twinned-cubic-crystal theory and the Penrose-tiling-six-dimensional-projection theory, is described. Values of the primitive-cubic lattice constant for several quasicrystals are evaluated from x-ray and neutron diffraction data. The fact that the low-angle diffraction maxima can be indexed with cubic unit cells provides additional support for the twinned-cubic-crystal theory of icosahedral quasicrystals. PMID:16593990

Enhanced solar-blind responsivity of photodetectors based on cubic MgZnO films via gallium doping.

PubMed

Xie, Xiuhua; Zhang, Zhenzhong; Li, Binghui; Wang, Shuangpeng; Jiang, Mingming; Shan, Chongxin; Zhao, Dongxu; Chen, Hongyu; Shen, Dezhen

2014-01-13

We report on gallium (Ga) doped cubic MgZnO films, which have been grown by metal organic chemical vapor deposition. It was demonstrated that Ga doping improves the n-type conduction of the cubic MgZnO films. A two-orders of magnitude enhancement in lateral n-type conduction have been achieved for the cubic MgZnO films. The responsivity of the cubic MgZnO-based photodetector has been also enhanced. Depletion region electric field intensity enhanced model was adopted to explain the improvement of quantum efficiency in Ga doped MgZnO-based detectors.

Low pressure growth of cubic boron nitride films

NASA Technical Reports Server (NTRS)

Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

1997-01-01

A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical vapor deposition. The cubic boron nitride film is useful as a substitute for diamond coatings for a variety of applications in which diamond is not suitable. any tetragonal or hexagonal boron nitride. The cubic boron nitride produced in accordance with the preceding example is particularly well-suited for use as a coating for ultra hard tool bits and abrasives, especially those intended to use in cutting or otherwise fabricating iron.

Implementation of PSF engineering in high-resolution 3D microscopy imaging with a LCoS (reflective) SLM

NASA Astrophysics Data System (ADS)

King, Sharon V.; Doblas, Ana; Patwary, Nurmohammed; Saavedra, Genaro; Martínez-Corral, Manuel; Preza, Chrysanthe

2014-03-01

Wavefront coding techniques are currently used to engineer unique point spread functions (PSFs) that enhance existing microscope modalities or create new ones. Previous work in this field demonstrated that simulated intensity PSFs encoded with a generalized cubic phase mask (GCPM) are invariant to spherical aberration or misfocus; dependent on parameter selection. Additional work demonstrated that simulated PSFs encoded with a squared cubic phase mask (SQUBIC) produce a depth invariant focal spot for application in confocal scanning microscopy. Implementation of PSF engineering theory with a liquid crystal on silicon (LCoS) spatial light modulator (SLM) enables validation of WFC phase mask designs and parameters by manipulating optical wavefront properties with a programmable diffractive element. To validate and investigate parameters of the GCPM and SQUBIC WFC masks, we implemented PSF engineering in an upright microscope modified with a dual camera port and a LCoS SLM. We present measured WFC PSFs and compare them to simulated PSFs through analysis of their effect on the microscope imaging system properties. Experimentally acquired PSFs show the same intensity distribution as simulation for the GCPM phase mask, the SQUBIC-mask and the well-known and characterized cubic-phase mask (CPM), first applied to high NA microscopy by Arnison et al.10, for extending depth of field. These measurements provide experimental validation of new WFC masks and demonstrate the use of the LCoS SLM as a WFC design tool. Although efficiency improvements are needed, this application of LCoS technology renders the microscope capable of switching among multiple WFC modes.

Pressure-Induced Phase Transitions in GeTe-Rich Ge-Sb-Te Alloys across the Rhombohedral-to-Cubic Transitions.

PubMed

Krbal, Milos; Bartak, Jaroslav; Kolar, Jakub; Prytuliak, Anastasiia; Kolobov, Alexander V; Fons, Paul; Bezacier, Lucile; Hanfland, Michael; Tominaga, Junji

2017-07-17

We demonstrate that pressure-induced amorphization in Ge-Sb-Te alloys across the ferroelectric-paraelectric transition can be represented as a mixture of coherently distorted rhombohedral Ge 8 Sb 2 Te 11 and randomly distorted cubic Ge 4 Sb 2 Te 7 and high-temperature Ge 8 Sb 2 Te 11 phases. While coherent distortion in Ge 8 Sb 2 Te 11 does not prevent the crystalline state from collapsing into its amorphous counterpart in a similar manner to pure GeTe, the pressure-amorphized Ge 8 Sb 2 Te 11 phase begins to revert to the crystalline cubic phase at ∼9 GPa in contrast to Ge 4 Sb 2 Te 7 , which remains amorphous under ambient conditions when gradually decompressed from 40 GPa. Moreover, experimentally, it was observed that pressure-induced amorphization in Ge 8 Sb 2 Te 11 is a temperature-dependent process. Ge 8 Sb 2 Te 11 transforms into the amorphous phase at ∼27.5 and 25.2 GPa at room temperature and 408 K, respectively, and completely amorphizes at 32 GPa at 408 K, while some crystalline texture could be seen until 38 GPa (the last measurement point) at room temperature. To understand the origins of the temperature dependence of the pressure-induced amorphization process, density functional theory calculations were performed for compositions along the (GeTe) x - (Sb 2 Te 3 ) 1-x tie line under large hydrostatic pressures. The calculated results agreed well with the experimental data.

Electrostatic swelling of bicontinuous cubic lipid phases.

PubMed

Tyler, Arwen I I; Barriga, Hanna M G; Parsons, Edward S; McCarthy, Nicola L C; Ces, Oscar; Law, Robert V; Seddon, John M; Brooks, Nicholas J

2015-04-28

Lipid bicontinuous cubic phases have attracted enormous interest as bio-compatible scaffolds for use in a wide range of applications including membrane protein crystallisation, drug delivery and biosensing. One of the major bottlenecks that has hindered exploitation of these structures is an inability to create targeted highly swollen bicontinuous cubic structures with large and tunable pore sizes. In contrast, cubic structures found in vivo have periodicities approaching the micron scale. We have been able to engineer and control highly swollen bicontinuous cubic phases of spacegroup Im3m containing only lipids by (a) increasing the bilayer stiffness by adding cholesterol and (b) inducing electrostatic repulsion across the water channels by addition of anionic lipids to monoolein. By controlling the composition of the ternary mixtures we have been able to achieve lattice parameters up to 470 Å, which is 5 times that observed in pure monoolein and nearly twice the size of any lipidic cubic phase reported previously. These lattice parameters significantly exceed the predicted maximum swelling for bicontinuous cubic lipid structures, which suggest that thermal fluctuations should destroy such phases for lattice parameters larger than 300 Å.

Design and performance of tapered cubic anvil used for achieving higher pressure and larger sample cell

NASA Astrophysics Data System (ADS)

Han, Qi-Gang; Yang, Wen-Ke; Zhu, Pin-Wen; Ban, Qing-Chu; Yan, Ni; Zhang, Qiang

2013-07-01

In order to increase the maximum cell pressure of the cubic high pressure apparatus, we have developed a new structure of tungsten carbide cubic anvil (tapered cubic anvil), based on the principle of massive support and lateral support. Our results indicated that the tapered cubic anvil has some advantages. First, tapered cubic anvil can push the transfer rate of pressure well into the range above 36.37% compare to the conventional anvil. Second, the rate of failure crack decreases about 11.20% after the modification of the conventional anvil. Third, the limit of static high-pressure in the sample cell can be extended to 13 GPa, which can increase the maximum cell pressure about 73.3% than that of the conventional anvil. Fourth, the volume of sample cell compressed by tapered cubic anvils can be achieved to 14.13 mm3 (3 mm diameter × 2 mm long), which is three and six orders of magnitude larger than that of double-stage apparatus and diamond anvil cell, respectively. This work represents a relatively simple method for achieving higher pressures and larger sample cell.

Temperature and pressure tuneable swollen bicontinuous cubic phases approaching nature's length scales.

PubMed

Barriga, H M G; Tyler, A I I; McCarthy, N L C; Parsons, E S; Ces, O; Law, R V; Seddon, J M; Brooks, N J

2015-01-21

Bicontinuous cubic structures offer enormous potential in applications ranging from protein crystallisation to drug delivery systems and have been observed in cellular membrane structures. One of the current bottlenecks in understanding and exploiting these structures is that cubic scaffolds produced in vitro are considerably smaller in size than those observed in biological systems, differing by almost an order of magnitude in some cases. We have addressed this technological bottleneck and developed a methodology capable of manufacturing highly swollen bicontinuous cubic membranes with length scales approaching those seen in vivo. Crucially, these cubic systems do not require the presence of proteins. We have generated highly swollen Im3m symmetry bicontinuous cubic phases with lattice parameters of up to 480 Å, composed of ternary mixtures of monoolein, cholesterol and negatively charged lipid (DOPS or DOPG) and we have been able to tune their lattice parameters. The swollen cubic phases are highly sensitive to both temperature and pressure; these structural changes are likely to be controlled by a fine balance between lipid headgroup repulsions and lateral pressure in the hydrocarbon chain region.

High reflected cubic cavity as long path absorption cell for infrared gas sensing

NASA Astrophysics Data System (ADS)

Yu, Jia; Gao, Qiang; Zhang, Zhiguo

2014-10-01

One direct and efficient method to improve the sensitivity of infrared gas sensors is to increase the optical path length of gas cells according to Beer-Lambert Law. In this paper, cubic shaped cavities with high reflected inner coating as novel long path absorption cells for infrared gas sensing were developed. The effective optical path length (EOPL) for a single cubic cavity and tandem cubic cavities were investigated based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) measuring oxygen P11 line at 763 nm. The law of EOPL of a diffuse cubic cavity in relation with the reflectivity of the coating, the port fraction and side length of the cavity was obtained. Experimental results manifested an increase of EOPL for tandem diffuse cubic cavities as the decrease of port fraction of the connecting aperture f', and the EOPL equaled to the sum of that of two single cubic cavities at f'<0.01. The EOPL spectra at infrared wavelength range for different inner coatings including high diffuse coatings and high reflected metallic thin film coatings were deduced.

An improved transmutation method for quantitative determination of the components in multicomponent overlapping chromatograms.

PubMed

Shao, Xueguang; Yu, Zhengliang; Ma, Chaoxiong

2004-06-01

An improved method is proposed for the quantitative determination of multicomponent overlapping chromatograms based on a known transmutation method. To overcome the main limitation of the transmutation method caused by the oscillation generated in the transmutation process, two techniques--wavelet transform smoothing and the cubic spline interpolation for reducing data points--were adopted, and a new criterion was also developed. By using the proposed algorithm, the oscillation can be suppressed effectively, and quantitative determination of the components in both the simulated and experimental overlapping chromatograms is successfully obtained.

Melting line of polymeric nitrogen

NASA Astrophysics Data System (ADS)

Yakub, L. N.

2013-05-01

We made an attempt to predict location of the melting line of polymeric nitrogen using two equations for Helmholtz free energy: proposed earlier for cubic gauche-structure and developed recently for liquid polymerized nitrogen. The P-T relation, orthobaric densities and latent heat of melting were determined using a standard double tangent construction. The estimated melting temperature decreases with increasing pressure, alike the temperature of molecular-nonmolecular transition in solid. We discuss the possibility of a triple point (solid-molecular fluid-polymeric fluid) at ˜80 GPa and observed maximum of melting temperature of nitrogen.

Shell structures in aluminum nanocontacts at elevated temperatures

PubMed Central

2012-01-01

Aluminum nanocontact conductance histograms are studied experimentally from room temperature up to near the bulk melting point. The dominant stable configurations for this metal show a very early crossover from shell structures at low wire diameters to ionic subshell structures at larger diameters. At these larger radii, the favorable structures are temperature-independent and consistent with those expected for ionic subshell (faceted) formations in face-centered cubic geometries. When approaching the bulk melting temperature, these local stability structures become less pronounced as shown by the vanishing conductance histogram peak structure. PMID:22325572

A Local Net Volume Equation for Iowa

Treesearch

Jerold T. Hahn

1976-01-01

As a part of the 1974 Forest Survey of Iowa, the Station''s Forst Resources Evaluatioin Research Staff developed a merchantable tree volume equation and tables of coefficients for Iowa. They were developed for both board-foot (International ?-inch rule) and cubic foot volumes, for several species and species groups of growing-stock trees. The equation and...

Pennsylvania forests 2014

Treesearch

Thomas A. Albright; William H. McWilliams; Richard H. Widmann; Brett J. Butler; Susan J. Crocker; Cassandra M. Kurtz; Shawn Lehman; Tonya W. Lister; Patrick D. Miles; Randall S. Morin; Rachel Riemann; James E. Smith

2017-01-01

This report summarizes the third cycle of annualized inventory of Pennsylvania with field data collected from 2009 through 2014. Pennsylvania has 16.9 million acres of forest land dominated by sawtimber stands of oak/hickory and maple/beech/birch forest-type groups. Volumes continue to increase as the forests age with an average of 2,244 cubic feet per acre on...

Vermont's Forests 2007

Treesearch

Randall S. Morin; Chuck J. Barnett; Gary J. Brand; Brett J. Butler; Robert De Geus; Mark H. Hansen; Mark A. Hatfield; Cassandra M. Kurtz; W. Keith Moser; Charles H. Perry; Ron Piva; Rachel Riemann; Richard Widmann; Sandy Wilmot; Chris W. Woodall

2011-01-01

The first full annual inventory of Vermont's forests reports more than 4.5 million acres of forest land with an average volume of more than 2,200 cubic feet per acre. Forest land is dominated by the maple/beech/birch forest-type group, which occupies 70 percent of total forest land area. Sixty-three percent of forest land consists of large-diameter trees, 27...

New Hampshire's Forests 2007

Treesearch

Randall S. Morin; Chuck J. Barnett; Gary J. Brand; Brett J. Butler; Grant M. Domke; Susan Francher; Mark H. Hansen; Mark A. Hatfield; Cassandra M. Kurtz; W. Keith Moser; Charles H. Perry; Ron Piva; Rachel Riemann; Chris W. Woodall

2011-01-01

The first full annual inventory of New Hampshire's forests reports nearly 4.8 million acres of forest land with an average volume of nearly 2,200 cubic feet per acre. Forest land is dominated by the maple/beech/birch forest-type group, which occupies 53 percent of total forest land area. Fifty-seven percent of forest land consists of large-diameter trees, 32...

Historical trends of timber product output in the South

Treesearch

Tony G. Johnson; Daniel P. Stratton

1998-01-01

This report contains historical data of canvasses of primary wood-using plants conducted periodically in the 13 Southern States and presents changes in product output by year of survey species group, and product by thousand cubic feet and standard units. This data complements the Forest Inventory and Analysis periodic inventory of volume, growth, and removals from each...

Iowa's forest resources, 2005

Treesearch

Susan J. Crocker; Gary J. Brand; Aron Flickinger

2007-01-01

Report presents Iowa's annual inventory results for 2005. Estimates show that Iowa has more than 2.8 million acres of forest land. Total live-tree volume on forest land is 4.0 billion cubic feet. Ninety-eight percent of forest land is classified as timberland. Oak/hickory is the predominant forest-type group, representing 54 percent of timberland area. Growing-...

Illinois' Forests 2010

Treesearch

Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Tonya W. Lister; Dacia M. Meneguzzo; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

2013-01-01

The second full annual inventory of Illinois' forests, completed in 2010, reports more than 4.8 million acres of forest land and 97 tree species. Forest land is dominated by oak/hickory and elm/ash/cottonwood forest-type groups, which occupy 93 percent of total forest land area. The volume of growing stock on timberland totals 7.2 billion cubic feet. The average...

Kentucky's forests, 2004

Treesearch

Jeffery A. Turner; Christopher M. Oswalt; James L. Chamberlain; Roger C. Conner; Tony G. Johnson; Sonja N. Oswalt; KaDonna C. Randolph

2008-01-01

Forest land area in the Commonwealth of Kentucky amounted to 11.97 million acres, including 11.6 million acres of timberland. Over 110 different species, mostly hardwoods, account for an estimated 21.2 billion cubic feet of all live tree volume. Hardwood forest types occupy 85 percent of Kentucky’s timberland, and oak-hickory is the dominant forest-type group...

Tennessee's Forests, 2004

Treesearch

Christopher M. Oswalt; Sonja N. Oswalt; Tony G. Johnson; James L. Chamberlain; KaDonna C. Randolph; John W. Coulston

2009-01-01

Forest land area in Tennessee amounted to 13.78 million acres. About 125 different species, mostly hardwood, account for an estimated 22.6 billion cubic feet of all growing-stock volume on timberland in the State. Hardwood forest types occupy the vast majority of the State's forest land, and oak-hickory is the dominant forest-type group, accounting for about 10.1...

Georgia's timber, 1972

Treesearch

Herbert A. Knight; Joe P. McClure

1974-01-01

The fourth survey of Georgia's timber resource, completed in November 1972, shows improved timber supplies across most of the State since 1961. Inventory volume increased from 19.6 to 25.3 billion cubic feet, or by 29 percent. A group of counties south of the Altamaha river in Southeast Georgia was the only extensive area which experienced a reduction in timber...

The construction of high-accuracy schemes for acoustic equations

NASA Technical Reports Server (NTRS)

Tang, Lei; Baeder, James D.

1995-01-01

An accuracy analysis of various high order schemes is performed from an interpolation point of view. The analysis indicates that classical high order finite difference schemes, which use polynomial interpolation, hold high accuracy only at nodes and are therefore not suitable for time-dependent problems. Thus, some schemes improve their numerical accuracy within grid cells by the near-minimax approximation method, but their practical significance is degraded by maintaining the same stencil as classical schemes. One-step methods in space discretization, which use piecewise polynomial interpolation and involve data at only two points, can generate a uniform accuracy over the whole grid cell and avoid spurious roots. As a result, they are more accurate and efficient than multistep methods. In particular, the Cubic-Interpolated Psuedoparticle (CIP) scheme is recommended for computational acoustics.

Digital-model analysis of the effects of water-use alternatives on spring discharges Gooding and Jerome Counties, Idaho

USGS Publications Warehouse

Moreland, Joe A.

1976-01-01

Springs discharging from the Snake Plain aquifer contribute approximately 6,000 cubic feet per second (170 cubic metres per second) to flow in the Snake River between Milner and King Hill. Before irrigation began on the Snake River Plain north and east of the springs, total spring discharge was about 4,200 cubic feet per second (120 cubic meters per second). Increasing amounts of irrigated acreage from the early 1900's to the mid-1940's contributed more irrigation-return water to the aquifer resulting in increased discharge at the springs. Maximum discharge of about 6,800 cubic feet per second (190 cubic metres per second) occurred during the late 1940's and early 1950's. Increased use of pumped ground water for irrigation and changing irrigation practices have since resulted in a decline in spring discharge.

Second harmonic generation response of the cubic chalcogenides Ba( 6-x)Sr x[Ag( 4-y)Sn( y/4)](SnS 4) 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haynes, Alyssa S.; Liu, Te-Kun; Frazer, Laszlo

We synthesized the barium/strontium solid solution sequence Ba 6-xSr x[Ag( 4-y)Sn( y/4)](SnS 4) 4 for nonlinear optical (NLO) applications in the infrared (IR) via a flux synthesis route. All title compounds are isotypic, crystallizing in the cubic space group Imore » $$\\bar{_4}$$ 3d and are composed of a three-dimensional (3D) anionic framework of alternating corner-sharing SnS 4 and AgS 4 tetrahedra charge balanced by Ba and Sr. The shrinkage of Ba/Sr-S bond lengths causes the tetrahedra in the anionic framework to become more distorted, which results in a tunable band gap from 1.58 to 1.38 eV with increasing x values. The performance of the barium limit (x=0) is also superior to that of Sr (x=6), but surprisingly second harmonic generation (SHG) of the solid solution remains strong and is insensitive to the value of x over the range 0-3.8. Results show that the non-type-I phase-matched SHG produced by these cubic chalcogenides display intensities higher than the benchmark AgGaSe 2 from 600 to 1000 nm.« less

Hydrothermal recrystallization of transition metal nitroprussides. Formation of the most stable phases

NASA Astrophysics Data System (ADS)

Echevarría, F.; Reguera, L.; González M, M.; Galicia, J.; Ávila, M.; Reguera, E.

2018-02-01

Hydrothermal recrystallization appears to be an appropriate treatment to explore the structural diversity of porous coordination polymers. In this contribution, such a post-synthesis treatment is applied to divalent transition metal nitroprussides, T[Fe(CN)5NO]•xH2O with T =Mn, Fe, Co, Ni, Cu, Zn, Cd. This family of compounds forms an interesting series of nanoporous coordination polymers with a wide structural diversity, related to the synthesis route used and the solid hydration degree (x). The effect of a hydrothermal recrystallization of previously prepared fine powders using the precipitation method, on their crystal structure and related properties is herein discussed. In this series of coordination polymers, for Fe, Co, Ni the precipitated powders are obtained as cubic phase, with a high porosity related to presence of systematic vacancies for building unit [Fe(CN)5NO]. For Fe and Co a structural transition, from cubic to orthorhombic, was observed, which is associated to formation of a most compact structure. The crystal structure for the new orthorhombic phases was refined from the collected powder HR-XRD patterns. For Ni, the cubic phase remains stable even for large heating time, which is ascribed to the high polarizing power of this metal. The high porosity for the cubic phase allows an easy accommodation for the local deformations around the Ni atom coordination sphere. The structural information from XRD was complemented with CO2 and H2 adsorption and TG data, IR and UV-vis spectra, and magnetic measurements. The magnetic data, through the presence of spin-orbit coupling for Fe and Co in the two phases, provide fine details on the coordination environment for the metal linked at the N ends of the CN group.

Hole doping and structural transformation in CsTl1-xHgxCl3.

PubMed

Retuerto, Maria; Yin, Zhiping; Emge, Thomas J; Stephens, Peter W; Li, Man-Rong; Sarkar, Tapati; Croft, Mark C; Ignatov, Alexander; Yuan, Z; Zhang, S J; Jin, Changqing; Paria Sena, Robert; Hadermann, Joke; Kotliar, Gabriel; Greenblatt, Martha

2015-02-02

CsTlCl(3) and CsTlF(3) perovskites have been theoretically predicted to be superconductors when properly hole-doped. Both compounds have been previously prepared as pure compounds: CsTlCl(3) in a tetragonal (I4/m) and a cubic (Fm3̅m) perovskite polymorph and CsTlF(3) as a cubic perovskite (Fm3̅m). In this work, substitution of Tl in CsTlCl(3) with Hg is reported, in an attempt to hole-dope the system and induce superconductivity. The whole series CsTl(1-x)HgxCl(3) (x = 0.0, 0.1, 0.2, 0.4, 0.6, and 0.8) was prepared. CsTl(0.9)Hg(0.1)Cl(3) is tetragonal as the more stable phase of CsTlCl(3). However, CsTl(0.8)Hg(0.2)Cl(3) is already cubic with the space group Fm3̅m and with two different positions for Tl(+) and Tl(3+). For x = 0.4 and 0.5, solid solutions could not be formed. For x ≥ 0.6, the samples are primitive cubic perovskites with one crystallographic position for Tl(+), Tl(3+), and Hg(2+). All of the samples formed are insulating, and there is no signature of superconductivity. X-ray absorption spectroscopy indicates that all of the samples have a mixed-valence state of Tl(+) and Tl(3+). Raman spectroscopy shows the presence of the active Tl-Cl-Tl stretching mode over the whole series and the intensity of the Tl-Cl-Hg mode increases with increasing Hg content. First-principle calculations confirmed that the phases are insulators in their ground state and that Hg is not a good dopant in the search for superconductivity in this system.

Plastic fluctuations in empty crystals formed by cubic wireframe particles

NASA Astrophysics Data System (ADS)

McBride, John M.; Avendaño, Carlos

2018-05-01

We present a computer simulation study of the phase behavior of colloidal hard cubic frames, i.e., particles with nonconvex cubic wireframe geometry interacting purely by excluded volume. Despite the propensity of cubic wireframe particles to form cubic phases akin to their convex counterparts, these particles exhibit unusual plastic fluctuations in which a random and dynamic fraction of particles rotate around their lattice positions in the crystal lattice while the remainder of the particles remains fully ordered. We argue that this unexpected effect stems from the nonconvex geometry of the particles in which the faces of a particle can be penetrated by the vertices of the nearest neighbors even at high number densities.

Brookian stratigraphic plays in the National Petroleum Reserve - Alaska (NPRA)

USGS Publications Warehouse

Houseknecht, David W.

2003-01-01

The Brookian megasequence in the National Petroleum Reserve in Alaska (NPRA) includes bottomset and clinoform seismic facies of the Torok Formation (mostly Albian age) and generally coeval, topset seismic facies of the uppermost Torok Formation and the Nanushuk Group. These strata are part of a composite total petroleum system involving hydrocarbons expelled from three stratigraphic intervals of source rocks, the Lower Cretaceous gamma-ray zone (GRZ), the Lower Jurassic Kingak Shale, and the Triassic Shublik Formation. The potential for undiscovered oil and gas resources in the Brookian megasequence in NPRA was assessed by defining five plays (assessment units), one in the topset seismic facies and four in the bottomset-clinoform seismic facies. The Brookian Topset Play is estimated to contain between 60 (95-percent probability) and 465 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 239 million barrels. The Brookian Topset Play is estimated to contain between 0 (95-percent probability) and 679 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 192 billion cubic feet. The Brookian Clinoform North Play, which extends across northern NPRA, is estimated to contain between 538 (95-percent probability) and 2,257 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 1,306 million barrels. The Brookian Clinoform North Play is estimated to contain between 0 (95-percent probability) and 1,969 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 674 billion cubic feet. The Brookian Clinoform Central Play, which extends across central NPRA, is estimated to contain between 299 (95-percent probability) and 1,849 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 973 million barrels. The Brookian Clinoform Central Play is estimated to contain between 1,806 (95-percent probability) and 10,076 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 5,405 billion cubic feet. The Brookian Clinoform South-Shallow Play is estimated to contain between 0 (95-percent probability) and 1,254 (5-percent probability) million barrels of technically recoverable oil, with a mean (expected value) of 508 million barrels. The Brookian Clinoform South-Shallow Play is estimated to contain between 0 (95-percent probability) and 5,809 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 2,405 billion cubic feet. The Brookian Clinoform South-Deep Play is estimated to contain between 0 (95-percent probability) and 8,796 (5-percent probability) billion cubic feet of technically recoverable, nonassociated natural gas, with a mean (expected value) of 3,788 billion cubic feet. No technically recoverable oil is assessed in the Brookian Clinoform South-Deep Play, as it lies at depths that are entirely in the gas window. Among the Brookian stratigraphic plays in NPRA, the Brookian Clinoform North Play and the Brookian Clinoform Central Play are most likely to be objectives of exploration activity in the near-term future because they are estimated to contain multiple oil accumulations larger than 128 million barrels technically recoverable oil, and because some of those accumulations may occur near existing infrastructure in the eastern parts of the plays. The other Brookian stratigraphic plays are not likely to be the focus of exploration activity because they are estimated to contain maximum accumulation sizes that are smaller, but they may be an objective of satellite exploration if infrastructure is extended into the play areas. The total volumes of natural gas estimated to occur in B

Predicted cubic-foot yields of sawmill products for black cherry trees

Treesearch

Leland F. Hanks

1980-01-01

Equations and tables for estimating the cubic-foot volumes of lumber, sawdust, and sawmill residue for black cherry trees are presented. Also included are cubic-foot and board-foot predictions for the sawlog portion of the trees.

The defective nature of ice Ic and its implications for atmospheric science

NASA Astrophysics Data System (ADS)

Kuhs, W. F.; Hansen, T. C.

2009-04-01

The possible atmospheric implication of ice Ic (cubic ice) has already been suggested some time ago in the context of snow crystal formation [1]. New findings from air-borne measurements in cirrus clouds and contrails have put ice Ic into the focus of interest to understand the so-called "supersaturation puzzle" [2,3,4,5]. Our recent microstructural work on ice Ic [6,7] appears to be highly relevant in this context. We have found that ice Ic is characterized by a complex stacking fault pattern, which changes as a function of temperature as well as time. Indeed, from our own [8] and other group's work [9] one knows that (in contrast to earlier believe) ice Ic can form up to temperatures at least as high as 240K - thus in the relevant range for cirrus clouds. We have good preliminary evidence that the "cubicity" (which can be related to stacking fault probabilities) as well as the particle size of ice Ic are the relevant parameters for this correlation. The "cubicity" of stacking faulty ice Ic (established by diffraction) correlates nicely with the increased supersaturation at decreasing temperatures observed in cirrus clouds and contrails, a fact, which may be considered as further evidence for the presence of ice Ic. Moreover, the stacking faults lead to kinks in the outer shapes of the minute ice Ic crystals as seen by cryo scanning electron microscopy (cryo-SEM); these defective sites are likely to play some role in heterogeneous reactions in the atmosphere. The cryo-SEM work suggests that stacking-faulty ice Ic has many more active centres for such reactions than the usually considered thermodynamically stable form, ice Ih. [1] T Kobayashi & T Kuroda (1987) Snow Crystals. In: Morphology of Crystals (ed. I Sunagawa), Terra Scientific Publishing, Tokyo, pp.649-743. [2] DM Murphy (2003) Dehydration in cold clouds is enhanced by a transition from from cubic to hexagonal ice. Geophys.Res.Lett.,30, 2230, doi:10.1029/2003GL018566. [3] RS Gao & 19 other authors (2004) Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds. Science 303, 516-520. [4] T Peter, C Marcolli, P Spaichinger, T Corti, MC Baker & T Koop (2006) When dry air is too humid. Science 314, 1399-1402. [5] JE Shilling, MA Tolbert, OB Toon, EJ Jensen, BJ Murray & AK Bertram (2006) Measurements of the vapor pressure of cubic ice and their implications for atmospheric ice clouds. Geophys.Res.Lett. 33, 026671. [6] TC Hansen, MM Koza & WF Kuhs (2008) Formation and annealing of cubic ice: I Modelling of stacking faults. J.Phys.Cond.Matt. 20, 285104. [7] TC Hansen, MM Koza, P Lindner & WF Kuhs (2008) Formation and annealing of cubic ice: II. Kinetic study. J.Phys.Cond.Matt. 20, 285105. [8] WF Kuhs, G Genov, DK Staykova & AN Salamatin (2004) Ice perfection and the onset of anomalous preservation of gas hydrates. Phys.Chem.Chem.Phys. 6, 4917-4920. [9] BJ Murray, DA Knopf & AK Bertram (2005) The formation of cubic ice under conditions relevant to Earth's atmosphere. Nature 434, 292-205.

River gain and loss studies for the Red River of the North Basin, North Dakota and Minnesota

USGS Publications Warehouse

Williams-Sether, Tara

2004-01-01

The Dakota Water Resources Act passed by the U.S. Congress in 2000 authorized the Secretary of the Interior to conduct a comprehensive study of future water-quantity and -quality needs of the Red River of the North (Red River) Basin in North Dakota and of possible options to meet those water needs.  To obtain the river gain and loss information needed to properly account for available streamflow within the basin, available river gain and loss studies for the Sheyenne, Turtle, Forest, and Park Rivers in North Dakota and the Wild Rice, Sand Hill, Clearwater, South Branch Buffalo, and Otter Tail Rivers in Minnesota were reviewed.  Ground-water discharges for the Sheyenne River in a reach between Lisbon and Kindred, N. Dak., were about 28.8 cubic feet per second in 1963 and about 45.0 cubic feet per second in 1986.  Estimated monthly net evaporation losses for additional flows to the Sheyenne River from the Missouri River ranged from 1.4 cubic feet per second in 1963 to 51.0 cubic feet per second in 1976.  Maximum water losses for a reach between Harvey and West Fargo, N. Dak., for 1956-96 ranged from about 161 cubic feet per second for 1976 to about 248 cubic feet per second for 1977.  Streamflow gains of 1 to 1.5 cubic feet per second per mile were estimated for the Wild Rice, Sand Hill, and Clearwater Rivers in Minnesota.  The average ground-water discharge for a 5.2-mile reach of the Otter Tail River in Minnesota was about 14.1 cubic feet per second in August 1994.  The same reach lost about 14.1 cubic feet per second between February 1994 and June 1994 and about 21.2 cubic feet per second between August 1994 and August 1995.

CUBIC pathology: three-dimensional imaging for pathological diagnosis.

PubMed

Nojima, Satoshi; Susaki, Etsuo A; Yoshida, Kyotaro; Takemoto, Hiroyoshi; Tsujimura, Naoto; Iijima, Shohei; Takachi, Ko; Nakahara, Yujiro; Tahara, Shinichiro; Ohshima, Kenji; Kurashige, Masako; Hori, Yumiko; Wada, Naoki; Ikeda, Jun-Ichiro; Kumanogoh, Atsushi; Morii, Eiichi; Ueda, Hiroki R

2017-08-24

The examination of hematoxylin and eosin (H&E)-stained tissues on glass slides by conventional light microscopy is the foundation for histopathological diagnosis. However, this conventional method has some limitations in x-y axes due to its relatively narrow range of observation area and in z-axis due to its two-dimensionality. In this study, we applied a CUBIC pipeline, which is the most powerful tissue-clearing and three-dimensional (3D)-imaging technique, to clinical pathology. CUBIC was applicable to 3D imaging of both normal and abnormal patient-derived, human lung and lymph node tissues. Notably, the combination of deparaffinization and CUBIC enabled 3D imaging of specimens derived from paraffin-embedded tissue blocks, allowing quantitative evaluation of nuclear and structural atypia of an archival malignant lymphoma tissue. Furthermore, to examine whether CUBIC can be applied to practical use in pathological diagnosis, we performed a histopathological screening of a lymph node metastasis based on CUBIC, which successfully improved the sensitivity in detecting minor metastatic carcinoma nodules in lymph nodes. Collectively, our results indicate that CUBIC significantly contributes to retrospective and prospective clinicopathological diagnosis, which might lead to the establishment of a novel field of medical science based on 3D histopathology.

Transdermal delivery of paeonol using cubic gel and microemulsion gel

PubMed Central

Luo, Maofu; Shen, Qi; Chen, Jinjin

2011-01-01

Background The aim of this study was to develop new systems for transdermal delivery of paeonol, in particular microemulsion gel and cubic gel formulations. Methods Various microemulsion vehicles were prepared using isopropyl myristate as an oil phase, polyoxyethylated castor oil (Cremophor® EL) as a surfactant, and polyethylene glycol 400 as a cosurfactant. In the optimum microemulsion gel formulation, carbomer 940 was selected as the gel matrix, and consisted of 1% paeonol, 4% isopropyl myristate, 28% Cremophor EL/polyethylene glycol 400 (1:1), and 67% water. The cubic gel was prepared containing 3% paeonol, 30% water, and 67% glyceryl monooleate. Results A skin permeability test using excised rat skins indicated that both the cubic gel and microemulsion gel formulations had higher permeability than did the paeonol solution. An in vivo pharmacokinetic study done in rats showed that the relative bioavailability of the cubic gel and microemulsion gel was enhanced by about 1.51-fold and 1.28-fold, respectively, compared with orally administered paeonol suspension. Conclusion Both the cubic gel and microemulsion gel formulations are promising delivery systems to enhance the skin permeability of paeonol, in particular the cubic gel. PMID:21904450

The role of grain boundaries in hydrogen diffusion in metals at 25 C

NASA Technical Reports Server (NTRS)

Danford, M. D.

1993-01-01

The effect of grain size on hydrogen diffusion at 25 C was examined for 4340 steel (body-centered cubic) and for Inconel 718 (face-centered cubic). It was found that the effect of grain size is important for body-centered cubic structures, but plays a much less important role in face centered cubic structures. Accurate measurements of hydrogen desorption coefficients during hydrogen desorption show that these are not greatly different for both types of structures.

Sedimentation survey of Lago Cerrillos, Ponce, Puerto Rico, April-May 2008

USGS Publications Warehouse

Soler-López, Luis R.

2011-01-01

Lago Cerrillos dam, located in the municipality of Ponce in southern Puerto Rico, was constructed in 1991 as part of the multipurpose Rio Portugues and Bucana Project. This project provides flood protection, water supply, and recreation facilities for the municipio of Ponce. The reservoir had an original storage capacity of 38.03 million cubic meters at maximum conservation pool elevation of 174.65 meters above mean sea level and a drainage area of 45.32 square kilometers. Sedimentation in Lago Cerrillos reservoir has reduced the storage capacity from 38.03 million cubic meters in 1991 to 37.26 million cubic meters in 2008, which represents a total storage loss of about 2 percent. During July 29 to August 23, 2002, 8,492 cubic meters of sediment were removed from the Rio Cerrillos mouth of the reservoir. Taking into account this removed material, the total water-storage loss as of 2008 is 778,492 cubic meters, and the long-term annual water-storage capacity loss rate is about 45,794 cubic meters per year or about 0.12 percent per year. The Lago Cerrillos net sediment-contributing drainage area has an average sediment yield of about 1,069 cubic meters per square kilometer per year. Sediment accumulation in Lago Cerrillos is not uniformly distributed and averages about 3 meters in thickness. This represents a sediment deposition rate of about 18 centimeters per year. On the basis of the 2008 reservoir storage capacity of 37.26 million cubic meters per year and a long-term sedimentation rate of 45,794 cubic meters per year, Lago Cerrillos is estimated to have a useful life of about 814 years or until the year 2822.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shyer, E.B.

The New York State Development of Environmental Conservation`s Division of Mineral Resources is responsible for regulating the oil and gas industry and receiving operator`s annual well production reports. Production year 1970 and 627 active gas wells with reported production of 3 billion cubic feet by New York State operators. Ten years later in 1980, production had more than tripled to 15.5 billion cubic feet and reported active gas wells increased to 1,966. During 1990, reported gas production was 25 billion cubic feet from 5,536 active gas wells. The average production per gas well in 1970 was 4,773 thousand cubic feet.more » Average gas production per well peaked in 1978 with a reported production of 14 billion cubic feet by 1,431 active gas wells which averaged 9,821 thousand cubic feet per well. By 1994 the average production per well had decreased to 3,800 thousand cubic feet, a decrease of approximately 60%. The decrease in average well production is more a reflection of the majority of older wells reaching the lower end of their decline curve than a decrease in overall per well production. The number of completed gas wells increased following the rising price of gas. In 1970 gas was $0.30 per thousand cubic feet. By 1984 the price per thousand cubic feet had peaked at $4. After 1984 the price of gas started to decline while the number of active gas wells continued to increase. Sharp increases in gas production for certain counties such as Steuben in 1972 and 1973 and Chautauqua in 1980-83 reflects the discoveries of new fields such as Adrian Reef and Bass Island, respectively. The Stagecoach Field discovered in 1989 in Tioga County is the newest high producing field in New York State.« less

Effect of the introduction of oxide ion vacancies into cubic fluorite-type rare earth oxides on the NO decomposition catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masui, Toshiyuki; Nagai, Ryosuke; Imanaka, Nobuhito, E-mail: imanaka@chem.eng.osaka-u.ac.jp

2014-12-15

Cubic fluorite-type solid solutions based on Pr{sub 6}O{sub 11} and CeO{sub 2} were synthesized and oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice through the charge compensating mechanism by Mg{sup 2+} and/or Ca{sup 2+} doping into their lattices. The oxide anion vacancies bring about positive effect on NO decomposition catalysis. The reason for the increase in the catalytic activity was attributed to defect fluorite-type structures close to the C-type cubic one, because C-type cubic rare earth oxides, in which one-quarter of the oxygen atoms in the fluorite-type structure are removed, show high NO decomposition activity. In particular,more » the positive effect of the formation of oxide anion vacancies was significant for Pr{sub 6}O{sub 11} and its solid solutions, because the molar volume of Pr{sub 6}O{sub 11} is larger than that of CeO{sub 2}, and Pr{sub 6}O{sub 11} contains Pr{sup 3+} as well as Pr{sup 4+} and thereby a small amount of oxide anion vacancies exist inherently in the lattice. - Graphical abstract: Oxide anion vacancies intentionally introduced into the cubic fluorite-type lattice bring about positive effect on NO decomposition catalysis. - Highlights: • Cubic fluorite-type solid solutions were synthesized. • Oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice. • The oxide anion vacancies bring about positive effect on NO decomposition catalysis. • The activity was enhanced by making the structure close to the C-type cubic one.« less

Simulation of flow in the upper North Coast Limestone Aquifer, Manati-Vega Baja area, Puerto Rico

USGS Publications Warehouse

Cherry, Gregory S.

2001-01-01

A two-dimensional computer ground-water model was constructed of the Manati-Vega Baja area to improve the understanding of the unconfined upper aquifer within the North Coast Province of Puerto Rico. The modeled area covers approximately 79 square miles within the municipios of Manati and Vega Baja and small portions of Vega Alta and Barceloneta. Steady-state two-dimensional ground-water simulations were correlated to conditions prior to construction of the Laguna Tortuguero outlet channel in 1940 and calibrated to the observed potentiometric surface in March 1995. At the regional scale, the unconfined Upper North Coast Limestone aquifer is a diffuse ground-water flow system through the Aguada and Aymamon limestone units. The calibrated model input parameters for aquifer recharge varied from 2 inches per year in coastal areas to 18 inches per year in the upland areas south of Manati and Vega Baja. The calibrated transmissivity values ranged from less than 500 feet squared per day in the upland areas near the southern boundary to 70,000 feet squared per day in the areas west of Vega Baja. Increased ground-water withdrawals from 1.0 cubic foot per second for 1940 conditions to 26.3 cubic feet per second in 1995, has reduced the natural ground-water discharge to springs and wetland areas, and induced additional recharge from the rivers. The most important regional drainage feature is Laguna Tortuguero, which is the major ground-water discharge body for the upper aquifer, and has a drainage area of approximately 17 square miles. The discharge to the sea from Laguna Tortuguero through the outlet channel has been measured on a bi-monthly basis since 1974. The outflow represents a combination of ground- and surface-water discharge over the drainage area. Hydrologic conditions, prior to construction of the Laguna Tortuguero outlet channel in 1943, can be considered natural conditions with minimal ground-water pumpage (1.0 cubic foot per second), and heads in the lagoon were 2.4 feet higher. The model was calibrated to March 1995 conditions during a dry period of minimal aquifer recharge and relatively constant water levels in the upper aquifer. For the steady-state 1995 model simulation, however, ground-water pumpage had been increased to 26.3 cubic foot per second, due to increased demand for public water supply, the heads at 0.9 feet, and the outflow to the sea at Laguna Tortuguero had been lowered considerably. Simulated ground-water inflow for 1940 hydrologic conditions included 35.9 cubic feet per second from areal recharge, contributions from streamflow along the southern boundary of 1.6 cubic feet per second, and streamflow infiltration to the upper aquifer of 4.2 cubic feet per second. Simulated ground-water outflow for 1940 hydrologic conditions are discharge to springs of 17.4 cubic feet per second, total ground-water withdrawals of 1.0 cubic feet per second, and aquifer contribution to streamflow or wetland areas of 23.4 cubic feet per second. Simulated ground-water inflow for hydrologic conditions of March 1995 include d contributions from streamflow along the southern boundary of 1.6 cubic feet per second, areal recharge of 35.9 cubic feet per second, and streamflow infiltration to the upper aquifer of 11 cubic feet per second. Simulated ground-water outflow for hydrologic conditions of March 1995 are ground-water withdrawals of 26.3 cubic feet per second, discharge from springs of 7.3 cubic feet per second, and aquifer contribution to streamflow or wetland areas of 14 .9 cubic feet per second. The overall ground-water budget increased from 41.8 cubic feet per second for 1940 conditions to 48.6 cubic feet per second for the hydrologic conditions of March 1995. The increase in ground-water budget is a direct result of increased ground-water withdrawals, which induced greater streamflow infiltration. Simulated ground-water flux to Laguna Tortuguero for 1940 conditions was 11 cubic feet per second, which drop

Monotonicity preserving splines using rational cubic Timmer interpolation

NASA Astrophysics Data System (ADS)

Zakaria, Wan Zafira Ezza Wan; Alimin, Nur Safiyah; Ali, Jamaludin Md

2017-08-01

In scientific application and Computer Aided Design (CAD), users usually need to generate a spline passing through a given set of data, which preserves certain shape properties of the data such as positivity, monotonicity or convexity. The required curve has to be a smooth shape-preserving interpolant. In this paper a rational cubic spline in Timmer representation is developed to generate interpolant that preserves monotonicity with visually pleasing curve. To control the shape of the interpolant three parameters are introduced. The shape parameters in the description of the rational cubic interpolant are subjected to monotonicity constrained. The necessary and sufficient conditions of the rational cubic interpolant are derived and visually the proposed rational cubic Timmer interpolant gives very pleasing results.

Optical Quasi-Soliton Solutions for the Cubic-Quintic Nonlinear SCHRÖDINGER Equation with Variable Coefficients

NASA Astrophysics Data System (ADS)

Yang, Qin; Zhang, Jie-Fang

Optical quasi-soliton solutions for the cubic-quintic nonlinear Schrödinger equation (CQNLSE) with variable coefficients are considered. Based on the extended tanh-function method, we not only successfully obtained bright and dark quasi-soliton solutions, but also obtained the kink quasi-soliton solutions under certain parametric conditions. We conclude that the quasi-solitons induced by the combined effects of the group velocity dispersion (GVD) distribution, the nonlinearity distribution, higher-order nonlinearity distribution, and the amplification or absorption coefficient are quite different from those of the solitons induced only by the combined effects of the GVD, the nonlinearity distribution, and the amplification or absorption coefficient without considering the higher-order nonlinearity distribution (i.e. α(z)=0). Furthermore, we choose appropriate optical fiber parameters D(z) and R(z) to control the velocity of quasi-soliton and time shift, and discuss the evolution behavior of the special quasi-soliton.

Hyper-Raman and Raman scattering from the polar modes of PbMg1/3Nb2/3O3.

PubMed

Hehlen, B; Amouri, A; Al-Zein, A; Khemakhem, H

2014-01-08

Microhyper-Raman spectroscopy of PbMg(1/3)Nb(2/3)O(3) (PMN) single crystal is performed at room temperature. The use of an optical microscope working in backscattering geometry significantly reduces the LO signal, highlighting thereby the weak contributions underneath. We clearly identify the highest frequency transverse optic mode (TO3) in addition to the previously observed soft TO-doublet at low frequency and TO2 at intermediate frequency. TO3 exhibits strong inhomogeneous broadening but perfectly fulfils the hyper-Raman cubic selection rules. The analysis shows that hyper-Raman spectroscopy is sensitive to all the vibrations of the average cubic Pm3¯m symmetry group of PMN, the three polar F1u- and the silent F2u-symmetry modes. All these vibrations can be identified in the Raman spectra alongside other vibrational bands likely arising from symmetry breaking in polar nanoregions.

Catalyst comprising Ir or Ir and Ru for hydrazine decomposition

NASA Technical Reports Server (NTRS)

Armstrong, Warren E. (Inventor); Voge, Hervey H. (Inventor); Ryland, Lloyd B. (Inventor)

1978-01-01

A catalyst for hydrazine decomposition consisting essentially of a carrier having a pore volume of at least 0.1 cubic centimeters per gram and a specific surface area, measured in square meters per gram, equal to 195 (C.sub.p + 0.013 + 0.736 V.sub.p) where C.sub.p is the specific heat capacity of the carrier at about 25.degree. C in calories per gram per degree and V.sub.p is the pore volume of the carrier in cubic centimeters per gram and metal of the group consisting of iridium, and mixtures consisting of iridium and ruthenium deposited on said carrier in an amount between 20% and about 40% by weight of the catalyst and distributed through the pores thereof in discrete particles sufficiently separated from each other so that they do not sinter or fuse together when the catalyst is at hydrazine decomposition temperature.

TBGG- INTERACTIVE ALGEBRAIC GRID GENERATION

NASA Technical Reports Server (NTRS)

Smith, R. E.

1994-01-01

TBGG, Two-Boundary Grid Generation, applies an interactive algebraic grid generation technique in two dimensions. The program incorporates mathematical equations that relate the computational domain to the physical domain. TBGG has application to a variety of problems using finite difference techniques, such as computational fluid dynamics. Examples include the creation of a C-type grid about an airfoil and a nozzle configuration in which no left or right boundaries are specified. The underlying two-boundary technique of grid generation is based on Hermite cubic interpolation between two fixed, nonintersecting boundaries. The boundaries are defined by two ordered sets of points, referred to as the top and bottom. Left and right side boundaries may also be specified, and call upon linear blending functions to conform interior interpolation to the side boundaries. Spacing between physical grid coordinates is determined as a function of boundary data and uniformly spaced computational coordinates. Control functions relating computational coordinates to parametric intermediate variables that affect the distance between grid points are embedded in the interpolation formulas. A versatile control function technique with smooth cubic spline functions is also presented. The TBGG program is written in FORTRAN 77. It works best in an interactive graphics environment where computational displays and user responses are quickly exchanged. The program has been implemented on a CDC Cyber 170 series computer using NOS 2.4 operating system, with a central memory requirement of 151,700 (octal) 60 bit words. TBGG requires a Tektronix 4015 terminal and the DI-3000 Graphics Library of Precision Visuals, Inc. TBGG was developed in 1986.

Tunable photonic crystals with partial bandgaps from blue phase colloidal crystals and dielectric-doped blue phases.

PubMed

Stimulak, Mitja; Ravnik, Miha

2014-09-07

Blue phase colloidal crystals and dielectric nanoparticle/polymer doped blue phases are demonstrated to combine multiple components with different symmetries in one photonic material, creating a photonic crystal with variable and micro-controllable photonic band structure. In this composite photonic material, one contribution to the band structure is determined by the 3D periodic birefringent orientational profile of the blue phases, whereas the second contribution emerges from the regular array of the colloidal particles or from the dielectric/nanoparticle-doped defect network. Using the planewave expansion method, optical photonic bands of the blue phase I and II colloidal crystals and related nanoparticle/polymer doped blue phases are calculated, and then compared to blue phases with no particles and to face-centred-cubic and body-centred-cubic colloidal crystals in isotropic background. We find opening of local band gaps at particular points of Brillouin zone for blue phase colloidal crystals, where there were none in blue phases without particles or dopants. Particle size and filling fraction of the blue phase defect network are demonstrated as parameters that can directly tune the optical bands and local band gaps. In the blue phase I colloidal crystal with an additionally doped defect network, interestingly, we find an indirect total band gap (with the exception of one point) at the entire edge of SC irreducible zone. Finally, this work demonstrates the role of combining multiple - by symmetry - differently organised components in one photonic crystal material, which offers a novel approach towards tunable soft matter photonic materials.

CubiCal: Suite for fast radio interferometric calibration

NASA Astrophysics Data System (ADS)

Kenyon, J. S.; Smirnov, O. M.; Grobler, T. L.; Perkins, S. J.

2018-05-01

CubiCal implements several accelerated gain solvers which exploit complex optimization for fast radio interferometric gain calibration. The code can be used for both direction-independent and direction-dependent self-calibration. CubiCal is implemented in Python and Cython, and multiprocessing is fully supported.

Soaking it up: new lipid sponge phases and their applications

NASA Astrophysics Data System (ADS)

Brasnett, Christopher; Seddon, Annela

Recent work has demonstrated that cubic lipid systems may be doped with charged lipids, with important consequences for their physical properties. Among others, Tyler et al. have reported some of the largest lipid cubic phases seen to date using this technique. The sponge phase is a disordered bicontinuous phase, formed when the membrane curvature of a cubic phase is reduced through the addition of butane diol. Additionally, it is known that sponge phases may be converted back into highly ordered cubic ones. Whilst past work has concentrated on sponge phases formed from monoolein, we have investigated the properties and behaviour of a bipartite sponge phase formed of monoolein and DOPG, and their conversion to cubic phases using shear. Furthermore, as both the sponge and cubic phase are of interest with respect to their applications in protein crystallography, we have explored the interaction of the protein light-harvesting complex with the lipid system. CB is supported by a University of Bristol EPSRC funded studentship.

West Virginia Forests 2013

Treesearch

Randall S. Morin; Gregory W. Cook; Charles J. Barnett; Brett J. Butler; Susan J. Crocker; Mark A. Hatfield; Cassandra M. Kurtz; Tonya W. Lister; William G. Luppold; William H. McWilliams; Patrick D. Miles; Mark D. Nelson; Charles H. (Hobie) Perry; Ronald J. Piva; James E. Smith; Jim Westfall; Richard H. Widmann; Christopher W. Woodall

2016-01-01

The annual inventory of West Virginia's forests, completed in 2013, covers nearly 12.2 million acres of forest land with an average volume of more than 2,300 cubic feet per acre. This report is based data collected from 2,808 plots located across the State. Forest land is dominated by the oak/hickory forest-type group, which occupies 74 percent of total forest...

Crystal structure of low-symmetry rondorfite

NASA Astrophysics Data System (ADS)

Rastsvetaeva, R. K.; Zadov, A. E.; Chukanov, N. V.

2008-03-01

The crystal structure of an aluminum-rich variety of the mineral rondorfite with the composition Ca16[Mg2(Si7Al)(O31OH)]Cl4 from the skarns of the Verkhne-Chegemskoe plateau (the Kabardino-Balkarian Republic, the Northern Caucasus Region, Russia) was solved in the triclinic space group with the unit-cell parameters a = 15.100(2) Å, b = 15.110(2) Å, c = 15.092(2) Å, α = 90.06(1)°, β = 90.01(1)°, γ = 89.93(1)°, Z = 4, sp. gr. P1. The structural model consisting of 248 independent atoms was determined by the phase-correction method and refined to R = 3.8% with anisotropic displacement parameters based on all 7156 independent reflections with 7156 F > 3σ( F). The crystal structure is based on pentamers consisting of four Si tetrahedra linked by the central Mg tetrahedron. The structure can formally be refined in the cubic space group ( a = 15.105 Å, sp. gr. Fd overline 3 , seven independent positions) with anisotropic displacement parameters to R = 2.74% based on 579 reflections with F > 3σ( F) without accounting for more than 1000 observed reflections, which are inconsistent with the cubic symmetry of the crystal structure.

Rural counties chlamydia and gonorrhea rates in Pennsylvania among adolescents and young adults.

PubMed

Pinto, Casey N; Dorn, Lorah D; Chinchilli, Vernon M; Du, Ping; Chi, Guangqing

2017-09-01

American adolescents and young adults between the ages of 15 and 24 account for 50% of all sexually transmitted diseases (STDs) annually. Rural populations in this age group are often understudied, despite having factors that place them at higher risk for STDs. The purpose of this study was to evaluate the utility of time series analysis in the assessment of rural Pennsylvania county-level chlamydia and gonorrhea rates overtime (2004-2014) for 15- to 19- and 20- to 24-year-old age groups by gender. An exploratory analysis was completed using Pennsylvania STD surveillance case report and census data, to develop a linear mixed-effects model of the STD rate for each Pennsylvania county for the years 2004 through 2014 using 3-month increments. A cubic polynomial spline regression model was assumed over the 44 time points for each county to account for possible oscillations in the STD rate during the 11-year period. Eight out of 12 rural counties had a significant increase in chlamydia or gonorrhea rates, and five rural counties had significant decreases in chlamydia or gonorrhea rates from 2004 to 2014. Results from this study provide the first analysis of change in rates of STDs in rural settings and demonstrate the utility of time series analysis for populations with small sample sizes. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of vitamin E acetate and other lipids on the phase behavior of mesophases based on unsaturated monoglycerides.

PubMed

Sagalowicz, L; Guillot, S; Acquistapace, S; Schmitt, B; Maurer, M; Yaghmur, A; de Campo, L; Rouvet, M; Leser, M; Glatter, O

2013-07-02

The phase behavior of the ternary unsaturated monoglycerides (UMG)-DL-α-tocopheryl acetate-water system has been studied. The effects of lipid composition in both bulk and dispersed lyotropic liquid crystalline phases and microemulsions were investigated. In excess water, progressive addition of DL-α-tocopheryl acetate to a binary UMG mixture results in the following phase sequence: reversed bicontinuous cubic phase, reversed hexagonal (H(II)) phase, and a reversed microemulsion. The action of DL-α-tocopheryl acetate is then compared to that of other lipids such as triolein, limonene, tetradecane, and DL-α-tocopherol. The impact of solubilizing these hydrophobic molecules on the UMG-water phase behavior shows some common features. However, the solubilization of certain molecules, like DL-α-tocopherol, leads to the presence of the reversed micellar cubic phase (space group number 227 and symmetry Fd3m) while the solubilization of others does not. These differences in phase behavior are discussed in terms of physical-chemical characteristics of the added lipid molecule and its interaction with UMG and water. From an applications point of view, phase behavior as a function of the solubilized content of guest molecules (lipid additive in our case) is crucial since macroscopic properties such as molecular release depend strongly on the phase present. The effect of two hydrophilic emulsifiers, used to stabilize the aqueous dispersions of UMG, was studied and compared. Those were Pluronic F127, which is the most commonly used stabilizer for these kinds of inverted type structures, and the partially hydrolyzed emulsifier lecithin (Emultop EP), which is a well accepted food-grade emulsifier. The phase behavior of particles stabilized by the partially hydrolyzed lecithin is similar to that of bulk sample at full hydration, but this emulsifier interacts significantly with the internal structure and affects it much more than F127.

Study of structural properties of cubic InN films on GaAs(001) substrates by molecular beam epitaxy and migration enhanced epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casallas-Moreno, Y. L.; Perez-Caro, M.; Gallardo-Hernandez, S.

InN epitaxial films with cubic phase were grown by rf-plasma-assisted molecular beam epitaxy (RF-MBE) on GaAs(001) substrates employing two methods: migration-enhanced epitaxy (MEE) and conventional MBE technique. The films were synthesized at different growth temperatures ranging from 490 to 550 Degree-Sign C, and different In beam fluxes (BEP{sub In}) ranging from 5.9 Multiplication-Sign 10{sup -7} to 9.7 Multiplication-Sign 10{sup -7} Torr. We found the optimum conditions for the nucleation of the cubic phase of the InN using a buffer composed of several thin layers, according to reflection high-energy electron diffraction (RHEED) patterns. Crystallographic analysis by high resolution X-ray diffraction (HR-XRD)more » and RHEED confirmed the growth of c-InN by the two methods. We achieved with the MEE method a higher crystal quality and higher cubic phase purity. The ratio of cubic to hexagonal components in InN films was estimated from the ratio of the integrated X-ray diffraction intensities of the cubic (002) and hexagonal (1011) planes measured by X-ray reciprocal space mapping (RSM). For MEE samples, the cubic phase of InN increases employing higher In beam fluxes and higher growth temperatures. We have obtained a cubic purity phase of 96.4% for a film grown at 510 Degree-Sign C by MEE.« less

Pharmacokinetics and enhanced oral bioavailability in beagle dogs of cyclosporine A encapsulated in glyceryl monooleate/poloxamer 407 cubic nanoparticles

PubMed Central

Lai, Jie; Lu, Yi; Yin, Zongning; Hu, Fuqiang; Wu, Wei

2010-01-01

Efforts to improve the oral bioavailability of cyclosporine A (CyA) remains a challenge in the field of drug delivery. In this study, glyceryl monooleate (GMO)/poloxamer 407 cubic nanoparticles were evaluated as potential vehicles to improve the oral bioavailability of CyA. Cubic nanoparticles were prepared via the fragmentation of a bulk GMO/poloxamer 407 cubic phase gel by sonication and homogenization. The cubic inner structure formed was verified using Cryo-TEM. The mean diameters of the nanoparticles were about 180 nm, and the entrapment efficiency of these particles for CyA was over 85%. The in vitro release of CyA from these nanoparticles was less than 5% at 12 h. The results of a pharmacokinetic study in beagle dogs showed improved absorption of CyA from cubic nanoparticles as compared to microemulsion-based Neoral®; higher Cmax (1371.18 ± 37.34 vs 969.68 ± 176.3 ng mL−1), higher AUC0–t (7757.21 ± 1093.64 vs 4739.52 ± 806.30 ng h mL−1) and AUC0–∞ (9004.77 ± 1090.38 vs 5462.31 ± 930.76 ng h mL−1). The relative oral bioavailability of CyA cubic nanoparticles calculated on the basis of AUC0–∞ was about 178% as compared to Neoral®. The enhanced bioavailability of CyA is likely due to facilitated absorption by cubic nanoparticles rather than improved release. PMID:20161984

3D Power Line Extraction from Multiple Aerial Images.

PubMed

Oh, Jaehong; Lee, Changno

2017-09-29

Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters.

3D Power Line Extraction from Multiple Aerial Images

PubMed Central

Lee, Changno

2017-01-01

Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters. PMID:28961204

A Machine Learning Approach to Pedestrian Detection for Autonomous Vehicles Using High-Definition 3D Range Data

PubMed Central

Navarro, Pedro J.; Fernández, Carlos; Borraz, Raúl; Alonso, Diego

2016-01-01

This article describes an automated sensor-based system to detect pedestrians in an autonomous vehicle application. Although the vehicle is equipped with a broad set of sensors, the article focuses on the processing of the information generated by a Velodyne HDL-64E LIDAR sensor. The cloud of points generated by the sensor (more than 1 million points per revolution) is processed to detect pedestrians, by selecting cubic shapes and applying machine vision and machine learning algorithms to the XY, XZ, and YZ projections of the points contained in the cube. The work relates an exhaustive analysis of the performance of three different machine learning algorithms: k-Nearest Neighbours (kNN), Naïve Bayes classifier (NBC), and Support Vector Machine (SVM). These algorithms have been trained with 1931 samples. The final performance of the method, measured a real traffic scenery, which contained 16 pedestrians and 469 samples of non-pedestrians, shows sensitivity (81.2%), accuracy (96.2%) and specificity (96.8%). PMID:28025565

Interactions in higher-spin gravity: a holographic perspective

NASA Astrophysics Data System (ADS)

Sleight, Charlotte

2017-09-01

This review is an elaboration of recent results on the holographic re-construction of metric-like interactions in higher-spin gauge theories on anti-de Sitter space (AdS), employing their conjectured duality with free conformal field theories (CFTs). After reviewing the general approach and establishing the necessary intermediate results, we extract explicit expressions for the complete cubic action on AdSd+1 and the quartic self-interaction of the scalar on AdS4 for the type A minimal bosonic higher-spin theory from the three- and four- point correlation functions of single-trace operators in the free scalar O(N) vector model. For this purpose tools were developed to evaluate tree-level three-point Witten diagrams involving totally symmetric fields of arbitrary integer spin and mass, and the conformal partial wave expansions of their tree-level four-point Witten diagrams. We also discuss the implications of the holographic duality on the locality properties of interactions in higher-spin gauge theories.

A Machine Learning Approach to Pedestrian Detection for Autonomous Vehicles Using High-Definition 3D Range Data.

PubMed

Navarro, Pedro J; Fernández, Carlos; Borraz, Raúl; Alonso, Diego

2016-12-23

This article describes an automated sensor-based system to detect pedestrians in an autonomous vehicle application. Although the vehicle is equipped with a broad set of sensors, the article focuses on the processing of the information generated by a Velodyne HDL-64E LIDAR sensor. The cloud of points generated by the sensor (more than 1 million points per revolution) is processed to detect pedestrians, by selecting cubic shapes and applying machine vision and machine learning algorithms to the XY, XZ, and YZ projections of the points contained in the cube. The work relates an exhaustive analysis of the performance of three different machine learning algorithms: k-Nearest Neighbours (kNN), Naïve Bayes classifier (NBC), and Support Vector Machine (SVM). These algorithms have been trained with 1931 samples. The final performance of the method, measured a real traffic scenery, which contained 16 pedestrians and 469 samples of non-pedestrians, shows sensitivity (81.2%), accuracy (96.2%) and specificity (96.8%).

Estimating merchantable volumes of second growth Douglas-fir stands from total cubic volume and associated stand characteristics.

Treesearch

Richard L. Williamson; Robert O. Curtis

1980-01-01

Equations are given for estimating merchantable volumes of second-growth Douglas-fir stands to specified breast-high and top-diameter limits, in cubic feet or board feet, from total volume in cubic feet and certain associated stand characteristics.

Polymorphism in 2-X-adamantane derivatives (X = Cl, Br).

PubMed

Negrier, Philippe; Barrio, María; Tamarit, Josep Ll; Mondieig, Denise

2014-08-14

The polymorphism of two 2-X-adamantane derivatives, X = Cl, X = Br, has been studied by X-ray powder diffraction and normal- and high-pressure (up to 300 MPa) differential scanning calorimetry. 2-Br-adamantane displays a low-temperature orthorhombic phase (space group P212121, Z = 4) and a high-temperature plastic phase (Fm3̅m, Z = 4) from 277.9 ± 1.0 K to the melting point at 413.4 ± 1.0 K. 2-Cl-adamantane presents a richer polymorphic behavior through the temperature range studied. At low temperature it displays a triclinic phase (P1̅, Z = 2), which transforms to a monoclinic phase (C2/c, Z = 8) at 224.4 ± 1.0 K, both phases being ordered. Two high-temperature orientationally disordered are found for this compound, one hexagonal (P63/mcm, Z = 6) at ca. 241 K and the highest one, cubic (Fm3̅m, Z = 4), being stable from 244 ± 1.0 K up to the melting point at 467.5 ± 1.0 K. No additional phase appears due to the increase in pressure within the studied range. The intermolecular interactions are found to be weak, especially for the 2-Br-adamantane compound for which the Br···Br as well as C-Br···H distances are larger than the addition of the van der Waals radii, thus confirming the availability of this compound for building up diamondoid blocks.

X-ray diffraction and infrared spectroscopy studies of Ba(Fe1/2Nb1/2)O3-(Na1/2Bi1/2)TiO3 ceramics

NASA Astrophysics Data System (ADS)

Chandra, K. P.; Yadav, Anjana; Prasad, K.

2018-05-01

Ceramics (1-x)Ba(Fe1/2Nb1/2)O3-x(Na1/2Bi1/2)TiO3; 0≤x≤1.0 were prepared by conventional ceramic synthesis technique. Rietveld refinements of X-ray diffraction data of these ceramics were carried out using FullProf software and determined their crystal symmetry, space group and unit cell dimensions. Rietveld refinement revealed that Ba(Fe1/2Nb1/2)O3 has cubic structure with space group Pm 3 ¯ m and Na1/2Bi1/2)TiO3 has rhombohedral structure with space group R3c. Addition of (Na1/2Bi1/2)TiO3 to Ba(Fe1/2Nb1/2)O3 resulted in the change of unit cell structure from cubic to tetragonal (P4/mmm) for x = 0.75 and the X-Ray diffraction peaks slightly shift towards higher Bragg's angle, suggesting slight decrease in unit cell volume. SEM studies were carried out in order to access the quality of the prepared ceramics which showed a change in grain shapes with the increase of (Na1/2Bi1/2)TiO3 content. FTIR spectra confirmed the formation of perovskite type solid solutions.

Method of fabricating boron containing coatings

DOEpatents

Makowiecki, Daniel M.; Jankowski, Alan F.

1999-01-01

Hard coatings are fabricated from boron nitride, cubic boron nitride, and multilayer boron/cubic boron nitride, and the fabrication thereof involves magnetron sputtering in a selected atmosphere. These hard coatings may be applied to tools and engine and other parts, as well to reduce wear on tribological surfaces and electronic devices. These boron coatings contain no morphological growth features. For example, the boron is formed in an inert (e.g. argon) atmosphere, while the cubic boron nitride is formed in a reactive (e.g. nitrogen) atmosphere. The multilayer boron/cubic boron nitride, is produced by depositing alternate layers of boron and cubic boron nitride, with the alternate layers having a thickness of 1 nanometer to 1 micrometer, and at least the interfaces of the layers may be discrete or of a blended or graded composition.

Method of fabricating boron containing coatings

DOEpatents

Makowiecki, D.M.; Jankowski, A.F.

1999-04-27

Hard coatings are fabricated from boron nitride, cubic boron nitride, and multilayer boron/cubic boron nitride, and the fabrication thereof involves magnetron sputtering in a selected atmosphere. These hard coatings may be applied to tools and engine and other parts, as well to reduce wear on tribological surfaces and electronic devices. These boron coatings contain no morphological growth features. For example, the boron is formed in an inert (e.g. argon) atmosphere, while the cubic boron nitride is formed in a reactive (e.g. nitrogen) atmosphere. The multilayer boron/cubic boron nitride, is produced by depositing alternate layers of boron and cubic boron nitride, with the alternate layers having a thickness of 1 nanometer to 1 micrometer, and at least the interfaces of the layers may be discrete or of a blended or graded composition. 3 figs.

Local and average structures of BaTiO 3-Bi(Zn 1/2Ti 1/2)O 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Usher, Tedi-Marie; Iamsasri, Thanakorn; Forrester, Jennifer S.

The complex crystallographic structures of (1-x)BaTiO 3-xBi(Zn 1/2Ti 1/2)O 3 (BT-xBZT) are examined using high resolution synchrotron X-ray diffraction, neutron diffraction, and neutron pair distribution function (PDF) analyses. The short-range structures are characterized from the PDFs, and a combined analysis of the X-ray and neutron diffraction patterns is used to determine the long-range structures. Our results demonstrate that the structure appears different when averaged over different length scales. In all compositions, the local structures determined from the PDFs show local tetragonal distortions (i.e., c/a > 1). But, a box-car fitting analysis of the PDFs reveals variations at different length scales.more » For 0.80BT-0.20BZT and 0.90BT-0.10BZT, the tetragonal distortions decrease at longer atom-atom distances (e.g., 30 vs. 5 ). When the longest distances are evaluated (r > 40 ), the lattice parameters approach cubic. Neutron and X-ray diffraction yield further information about the long-range structure. Compositions 0.80BT-0.20BZT and 0.90BT-0.10BZT appear cubic by Bragg diffraction (no peak splitting), consistent with the PDFs at long distances. However, these patterns cannot be adequately fit using a cubic lattice model; modeling their structures with the P4mm space group allows for a better fit to the patterns because the space group allows for c-axis atomic displacements that occur at the local scale. Furthermore, for the compositions 0.92BT-0.08BZT and 0.94BT-0.06BZT, strong tetragonal distortions are observed at the local scale and a less-distorted tetragonal structure is observed at longer length scales. In Rietveld refinements, the latter is modeled using a tetragonal phase. Since the peak overlap in these two-phase compositions limits the ability to model the local-scale structures as tetragonal, it is approximated in the refinements as a cubic phase. These results demonstrate that alloying BT with BZT results in increased disorder and disrupts the long-range ferroelectric symmetry present in BT, while the large tetragonal distortion present in BZT persists at the local scale.« less

Local and average structures of BaTiO 3-Bi(Zn 1/2Ti 1/2)O 3

DOE PAGES

Usher, Tedi-Marie; Iamsasri, Thanakorn; Forrester, Jennifer S.; ...

2016-11-11

The complex crystallographic structures of (1-x)BaTiO 3-xBi(Zn 1/2Ti 1/2)O 3 (BT-xBZT) are examined using high resolution synchrotron X-ray diffraction, neutron diffraction, and neutron pair distribution function (PDF) analyses. The short-range structures are characterized from the PDFs, and a combined analysis of the X-ray and neutron diffraction patterns is used to determine the long-range structures. Our results demonstrate that the structure appears different when averaged over different length scales. In all compositions, the local structures determined from the PDFs show local tetragonal distortions (i.e., c/a > 1). But, a box-car fitting analysis of the PDFs reveals variations at different length scales.more » For 0.80BT-0.20BZT and 0.90BT-0.10BZT, the tetragonal distortions decrease at longer atom-atom distances (e.g., 30 vs. 5 ). When the longest distances are evaluated (r > 40 ), the lattice parameters approach cubic. Neutron and X-ray diffraction yield further information about the long-range structure. Compositions 0.80BT-0.20BZT and 0.90BT-0.10BZT appear cubic by Bragg diffraction (no peak splitting), consistent with the PDFs at long distances. However, these patterns cannot be adequately fit using a cubic lattice model; modeling their structures with the P4mm space group allows for a better fit to the patterns because the space group allows for c-axis atomic displacements that occur at the local scale. Furthermore, for the compositions 0.92BT-0.08BZT and 0.94BT-0.06BZT, strong tetragonal distortions are observed at the local scale and a less-distorted tetragonal structure is observed at longer length scales. In Rietveld refinements, the latter is modeled using a tetragonal phase. Since the peak overlap in these two-phase compositions limits the ability to model the local-scale structures as tetragonal, it is approximated in the refinements as a cubic phase. These results demonstrate that alloying BT with BZT results in increased disorder and disrupts the long-range ferroelectric symmetry present in BT, while the large tetragonal distortion present in BZT persists at the local scale.« less

Environmental assessment for the Plating Shop Replacement, Y-12 Plant, Oak Ridge, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-03-01

The existing of Y-12 Plant Plating Shop provides vital support functions for the US Department of Energy (DOE) Defense Programs operations. In addition to weapon component plating, the facility performs other plating services to support existing operations for the Y-12 Plant, other DOE facilities, and other federal agencies. In addition, the facility would also provide essential deplating services for weapons reclamation and teardown. The existing Y-12 Plant Plating Shop is presently located in a structure which is rapidly deteriorating and obsolete. The existing building structure was originally designed to house a steam plant, not chemical plating operations. As such, vaporsmore » from plating operations have deteriorated the structure to a point where a new facility is needed for continued safe operations. The potential environmental impacts of the proposed action was anticipated to be minimal and would affect no environmentally sensitive areas. Some short-term construction- and demolition-related effects would occur in an already highly industrialized setting. These include temporarily disturbing 72,000 square feet of land for the new plating shop and related site preparation activities, constructing a permanent building on part of the area, and using 80 construction personnel over a period of 18 months for site preparation and construction. Demolition effects vary depending on the environmentally suitable option selected, but they could involve as much as 262 cubic yards of concrete rubble and approximately 1600 cubic yards of soil disposed as waste. Either 1600 cubic yards of fresh soil or 1850 yards of clay and fresh soil could be required. Soil erosion would be minimal. Approximately 20 construction personnel would be involved for 12 months in demolition activities.« less

Dynamic properties of III-V polytypes from density-functional theory

NASA Astrophysics Data System (ADS)

Benyahia, N.; Zaoui, A.; Madouri, D.; Ferhat, M.

2017-03-01

The recently discovered hexagonal wurtzite phase of several III-V nanowires opens up strong opportunity to engineer optoelectronic and transport properties of III-V materials. Herein, we explore the dynamical and dielectric properties of cubic (3C) and wurtzite (2H) III-V compounds (AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, and InSb). For cubic III-V compounds, our calculated phonon frequencies agree well with neutron diffraction and Raman-scattering measurements. In the case of 2H III-V materials, our calculated phonon modes at the zone-center Γ point are in distinguished agreement with available Raman-spectroscopy measurements of wurtzite GaAs, InP, GaP, and InAs nanowires. Particularly, the "fingerprint" of the wurtzite phase, which is our predicted E2(high) phonon mode, at 261 cm-1(GaAs), 308 cm-1(InP), 358 cm-1(GaP), and 214 cm-1(InAs) matches perfectly the respective Raman values of 258 cm-1, 306.4 cm-1, 353 cm-1, and 213.7 cm-1 for GaAs, InP, GaP, and InAs. Moreover, the dynamic charges and high-frequency dielectric constants are predicted for III-V materials in both cubic (3C) and hexagonal (2H) crystal polytypes. It is found that the dielectric properties of InAs and InSb contrast markedly from those of other 2H III-V compounds. Furthermore, InAs and InSb evidence relative strong anisotropy in their dielectric constants and Born effective charges, whereas GaP evinces the higher Born effective charge anisotropy of 2H III-V compounds.

Europium gallium garnet (Eu3Ga5O12) and Eu3GaO6: Synthesis and material properties

NASA Astrophysics Data System (ADS)

Sawada, Kenji; Nakamura, Toshihiro; Adachi, Sadao

2016-10-01

Eu-Ga-O ternary compounds were synthesized from a mixture of cubic (c-) Eu2O3 and monoclinic Ga2O3 (β-Ga2O3) raw powders using the solid-state reaction method by calcination at Tc = 1200 °C. The structural and optical properties of the Eu-Ga-O ternary compounds were investigated using X-ray diffraction analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and Raman scattering measurements. Stoichiometric compounds such as cubic Eu3Ga5O12 (EGG) and orthorhombic Eu3GaO6 were synthesized using molar ratios of x = 0.375 and 0.75 [x≡Eu2O3/(Eu2O3 + Ga2O3)], respectively, together with the end-point binary compounds β-Ga2O3 (x = 0) and monoclinic (m-) Eu2O3 (x = 1.0). The structural change from "cubic" to "monoclinic" in Eu2O3 is due to the structural phase transition occurring at Tc ≥ 1050 °C. In principle, the perovskite-type EuGaO3 and monoclinic Eu4Ga2O9 can also be synthesized at x = 0.5 and 0.667, respectively; however, such stoichiometric compounds could not be synthesized in this study. The PL and PLE properties of EGG and Eu3GaO6 were studied in detail. The temperature dependence of the PL spectra was observed through measurements carried out between T = 20 and 300 K and explained using a newly developed model. Raman scattering measurements were also performed on the Eu-Ga-O ternary systems over the entire composition range from x = 0 (β-Ga2O3) to 1.0 (m-Eu2O3).

Hydrologic reconnaissance of the Noatak River basin, Alaska, 1978

USGS Publications Warehouse

Childers, Joseph M.; Kernodle, Donald R.

1981-01-01

Hydrologic data were collected in 1978 described water resources of the Noatak River basin, Alaska. Streamflow varies seasonally. No flow was observed from the upper part of the basin in late winter (April). In the lower part of the basin springs support perennial flow in the Kugururok River and downstream along the Noatak. The discharge of the Noatak was 150 cubic feet per second in April 1978. During the summer, rainstorms are common, and runoff produces high flow. During August 1978, flow was normal in the basin; unit runoff averaged about 1 cubic foot per second per square mile. The Noatak is a gravel-bed stream of moderate slope. It drops about 1,800 feet in elevation from a point near the head waters to the mouth, a distance of 400 miles. Streambed material in most places is gravel, cobbles, and boulders, maximum riffle depths and pool widths increase in a downstream direction. Stream velocity in August 1978 increased from about 1 foot per second in the upper basin to about 4 feet per second in the lower reaches. High-water marks of the maximum evident flood were found at elevations from bankfull to 5 feet above bankfull. Maximum evident flood unit runoff rates were estimated to be less than 50 cubic feet per second per square mile. Scars produced by ice jams were seldom seen above bankfull. Bank erosion appears to be most active in the lowlands. Water in the Noatak River basin is virtually unaffected by man 's activity. Water quality varies with location, weather, season, and source; the water is normally clear, cool, and hard. During late winter sea water intrudes into the Lower Noatak Canyon. Benthic invertebrate community composition and variability suggest the river 's undiminished natural quality. (USGS)

Investigation of methods for successful installation and operation of Juvenile Salmon Acoustic Telemetry System (JSATS) hydrophones in the Willamette River, Oregon, 2012

USGS Publications Warehouse

Rutz, Gary L.; Sholtis, Matthew D.; Adams, Noah S.; Beeman, John W.

2014-01-01

Acoustic telemetry equipment was installed at three sites in the Willamette River during October 2012 to test the effectiveness of using the Juvenile Salmon Acoustic Telemetry System to monitor the movements of fish in a high-flow, high-velocity riverine environment. Hydrophones installed on concrete blocks were placed on the bottom of the river, and data cables were run from the hydrophones to shore where they were attached to anchor points. Under relatively low-flow conditions (less than approximately 10,000 cubic feet per second) the monitoring system remained in place and could be used to detect tagged fish as they traveled downstream during their seaward migration. At river discharge over approximately 10,000 cubic feet per second, the hydrophones were damaged and cables were lost because of the large volume of woody debris in the river and the increase in water velocity. Damage at two of the sites was sufficient to prevent data collection. A limited amount of data was collected from the equipment at the third site. Site selection and deployment strategies were re-evaluated, and an alternate deployment methodology was designed for implementation in 2013.

Structural and magnetic properties of SrMn1-xRuxO3 perovskites

NASA Astrophysics Data System (ADS)

Dabrowski, B.; Kolesnik, S.; Chmaissem, O.; Maxwell, T.

2007-03-01

Ferromagnetism of SrRuO3 is unique among 4d transition metal based perovskite oxides. On substitution of Mn its TC decreases from 163 K to 0 for x˜0.5-0.6 followed by a formation of an antiferromagnetic insulating state at a quantum critical point. The other end member of the SrMn1-xRuxO3 family, a cubic perovskite SrMnO3 is a G-type antiferromagnet with TN=233 K. We have synthesized the complete SrMn1-xRuxO3 solid solution. The polycrystalline samples were characterized by neutron difraction, magnetic, and transport experiments. The incorporation of Ru in the SrMnO3 matrix (0.1<=x<=0.4) results in a phase transition to a C-type antiferromagnetic state accompanied by a cubic-tetragonal transition. The intermediate substitution level induces a spin-glass behavior, due to competing ferro- and antiferromagnetic interactions. Mixed valence Mn^3+/Mn^4+ and Ru^4+/Ru^5+ pairs introduce additional frustration to the magnetic states. The glassy behavior can be observed for x up to 0.7 in the tetragonal structure. Supported by NSF (DMR-0302617) and the U.S. Department of Education

Initial stages of ion beam-induced phase transformations in Gd2O3 and Lu2O3

NASA Astrophysics Data System (ADS)

Chen, Chien-Hung; Tracy, Cameron L.; Wang, Chenxu; Lang, Maik; Ewing, Rodney C.

2018-02-01

The atomic-scale evolution of lanthanide sesquioxides Gd2O3 and Lu2O3 irradiated with 1 MeV Kr ions at room temperature and 120 K, up to fluences of 1 × 1016 ions/cm2 (˜20 dpa), has been characterized by in situ transmission electron microscopy. At room temperature, both oxides exhibited high radiation tolerance. Irradiation did not cause any observable structural change in either material, likely due to the mobility of irradiation-induced point defects, causing efficient defect annihilation. For Gd2O3, having the larger cation ionic radius of the two materials, an irradiation-induced stacking fault structure appeared at low fluences in the low temperature irradiation. As compared with the cubic-to-monoclinic phase transformations known to result from higher energy (˜GeV) ion irradiation, Kr ions of lower energies (˜MeV) yield much lower rates of damage accumulation and thus less extensive structural modification. At a fluence of 2.5 × 1015 ions/cm2, only the initial stages of the cubic-to-monoclinic (C to B) phase transformation process, consisting of the formation and aggregation of defects, have been observed.

Stabilities and defect-mediated lithium-ion conduction in a ground state cubic Li 3 N structure

DOE PAGES

Nguyen, Manh Cuong; Hoang, Khang; Wang, Cai-Zhuang; ...

2016-01-07

A stable ground state structure with cubic symmetry of Li 3N (c-Li 3N) is found by ab initio initially symmetric random-generated crystal structure search method. Gibbs free energy, calculated within quasi-harmonic approximation, shows that c-Li 3N is the ground state structure for a wide range of temperature. The c-Li 3N structure has a negative thermal expansion coefficient at temperatures lower than room temperature, due mainly to two transverse acoustic phonon modes. This c-Li 3N phase is a semiconductor with an indirect band gap of 1.90 eV within hybrid density functional calculation. We also investigate the migration and energetics of nativemore » point defects in c-Li 3N, including lithium and nitrogen vacancies, interstitials, and anti-site defects. Lithium interstitials are found to have a very low migration barrier (~0.12 eV) and the lowest formation energy among all possible defects. Thus, the ionic conduction in c-Li 3N is expected to occur via an interstitial mechanism, in contrast to that in the well-known α-Li 3N phase which occurs via a vacancy mechanism.« less

Computational study of Ca, Sr and Ba under pressure

NASA Astrophysics Data System (ADS)

Jona, F.; Marcus, P. M.

2006-05-01

A first-principles procedure for the calculation of equilibrium properties of crystals under hydrostatic pressure is applied to Ca, Sr and Ba. The procedure is based on minimizing the Gibbs free energy G (at zero temperature) with respect to the structure at a given pressure p, and hence does not require the equation of state to fix the pressure. The calculated lattice constants of Ca, Sr and Ba are shown to be generally closer to measured values than previous calculations using other procedures. In particular for Ba, where careful and extensive pressure data are available, the calculated lattice parameters fit measurements to about 1% in three different phases, both cubic and hexagonal. Rigid-lattice transition pressures between phases which come directly from the crossing of G(p) curves are not close to measured transition pressures. One reason is the need to include zero-point energy (ZPE) of vibration in G. The ZPE of cubic phases is calculated with a generalized Debye approximation and applied to Ca and Sr, where it produces significant shifts in transition pressures. An extensive tabulation is given of structural parameters and elastic constants from the literature, including both theoretical and experimental results.

Simulation of Pellet Ablation

NASA Astrophysics Data System (ADS)

Parks, P. B.; Ishizaki, Ryuichi

2000-10-01

In order to clarify the structure of the ablation flow, 2D simulation is carried out with a fluid code solving temporal evolution of MHD equations. The code includes electrostatic sheath effect at the cloud interface.(P.B. Parks et al.), Plasma Phys. Contr. Fusion 38, 571 (1996). An Eulerian cylindrical coordinate system (r,z) is used with z in a spherical pellet. The code uses the Cubic-Interpolated Psudoparticle (CIP) method(H. Takewaki and T. Yabe, J. Comput. Phys. 70), 355 (1987). that divides the fluid equations into non-advection and advection phases. The most essential element of the CIP method is in calculation of the advection phase. In this phase, a cubic interpolated spatial profile is shifted in space according to the total derivative equations, similarly to a particle scheme. Since the profile is interpolated by using the value and the spatial derivative value at each grid point, there is no numerical oscillation in space, that often appears in conventional spline interpolation. A free boundary condition is used in the code. The possibility of a stationary shock will also be shown in the presentation because the supersonic ablation flow across the magnetic field is impeded.

Stability of the body-centred-cubic phase of iron in the Earth's inner core.

PubMed

Belonoshko, Anatoly B; Ahuja, Rajeev; Johansson, Börje

2003-08-28

Iron is thought to be the main constituent of the Earth's core, and considerable efforts have therefore been made to understand its properties at high pressure and temperature. While these efforts have expanded our knowledge of the iron phase diagram, there remain some significant inconsistencies, the most notable being the difference between the 'low' and 'high' melting curves. Here we report the results of molecular dynamics simulations of iron based on embedded atom models fitted to the results of two implementations of density functional theory. We tested two model approximations and found that both point to the stability of the body-centred-cubic (b.c.c.) iron phase at high temperature and pressure. Our calculated melting curve is in agreement with the 'high' melting curve, but our calculated phase boundary between the hexagonal close packed (h.c.p.) and b.c.c. iron phases is in good agreement with the 'low' melting curve. We suggest that the h.c.p.-b.c.c. transition was previously misinterpreted as a melting transition, similar to the case of xenon, and that the b.c.c. phase of iron is the stable phase in the Earth's inner core.

Construction of a WMR for trajectory tracking control: experimental results.

PubMed

Silva-Ortigoza, R; Márquez-Sánchez, C; Marcelino-Aranda, M; Marciano-Melchor, M; Silva-Ortigoza, G; Bautista-Quintero, R; Ramos-Silvestre, E R; Rivera-Díaz, J C; Muñoz-Carrillo, D

2013-01-01

This paper reports a solution for trajectory tracking control of a differential drive wheeled mobile robot (WMR) based on a hierarchical approach. The general design and construction of the WMR are described. The hierarchical controller proposed has two components: a high-level control and a low-level control. The high-level control law is based on an input-output linearization scheme for the robot kinematic model, which provides the desired angular velocity profiles that the WMR has to track in order to achieve the desired position (x∗, y∗) and orientation (φ∗). Then, a low-level control law, based on a proportional integral (PI) approach, is designed to control the velocity of the WMR wheels to ensure those tracking features. Regarding the trajectories, this paper provides the solution or the following cases: (1) time-varying parametric trajectories such as straight lines and parabolas and (2) smooth curves fitted by cubic splines which are generated by the desired data points {(x₁∗, y₁∗),..., (x(n)∗, y(n)∗)}. A straightforward algorithm is developed for constructing the cubic splines. Finally, this paper includes an experimental validation of the proposed technique by employing a DS1104 dSPACE electronic board along with MATLAB/Simulink software.

Construction of a WMR for Trajectory Tracking Control: Experimental Results

PubMed Central

Silva-Ortigoza, R.; Márquez-Sánchez, C.; Marcelino-Aranda, M.; Marciano-Melchor, M.; Silva-Ortigoza, G.; Bautista-Quintero, R.; Ramos-Silvestre, E. R.; Rivera-Díaz, J. C.; Muñoz-Carrillo, D.

2013-01-01

This paper reports a solution for trajectory tracking control of a differential drive wheeled mobile robot (WMR) based on a hierarchical approach. The general design and construction of the WMR are described. The hierarchical controller proposed has two components: a high-level control and a low-level control. The high-level control law is based on an input-output linearization scheme for the robot kinematic model, which provides the desired angular velocity profiles that the WMR has to track in order to achieve the desired position (x∗, y∗) and orientation (φ∗). Then, a low-level control law, based on a proportional integral (PI) approach, is designed to control the velocity of the WMR wheels to ensure those tracking features. Regarding the trajectories, this paper provides the solution or the following cases: (1) time-varying parametric trajectories such as straight lines and parabolas and (2) smooth curves fitted by cubic splines which are generated by the desired data points {(x1∗, y1∗),..., (xn∗, yn∗)}. A straightforward algorithm is developed for constructing the cubic splines. Finally, this paper includes an experimental validation of the proposed technique by employing a DS1104 dSPACE electronic board along with MATLAB/Simulink software. PMID:23997679

Anisotropy effects in magnetic hyperthermia: A comparison between spherical and cubic exchange-coupled FeO/Fe{sub 3}O{sub 4} nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khurshid, H., E-mail: khurshid@usf.edu, E-mail: sharihar@usf.edu; Nemati, Z.; Phan, M. H.

2015-05-07

Spherical and cubic exchange-coupled FeO/Fe{sub 3}O{sub 4} nanoparticles, with different FeO:Fe{sub 3}O{sub 4} ratios, have been prepared by a thermal decomposition method to probe anisotropy effects on their heating efficiency. X-ray diffraction and transmission electron microscopy reveal that the nanoparticles are composed of FeO and Fe{sub 3}O{sub 4} phases, with an average size of ∼20 nm. Magnetometry and transverse susceptibility measurements show that the effective anisotropy field is 1.5 times larger for the cubes than for the spheres, while the saturation magnetization is 1.5 times larger for the spheres than for the cubes. Hyperthermia experiments evidence higher values of the specificmore » absorption rate (SAR) for the cubes as compared to the spheres (200 vs. 135 W/g at 600 Oe and 310 kHz). These observations point to an important fact that the saturation magnetization is not a sole factor in determining the SAR and the heating efficiency of the magnetic nanoparticles can be improved by tuning their effective anisotropy.« less

An extended UTD analysis for the scattering and diffraction from cubic polynomial strips

NASA Technical Reports Server (NTRS)

Constantinides, E. D.; Marhefka, R. J.

1993-01-01

Spline and polynomial type surfaces are commonly used in high frequency modeling of complex structures such as aircraft, ships, reflectors, etc. It is therefore of interest to develop an efficient and accurate solution to describe the scattered fields from such surfaces. An extended Uniform Geometrical Theory of Diffraction (UTD) solution for the scattering and diffraction from perfectly conducting cubic polynomial strips is derived and involves the incomplete Airy integrals as canonical functions. This new solution is universal in nature and can be used to effectively describe the scattered fields from flat, strictly concave or convex, and concave convex boundaries containing edges. The classic UTD solution fails to describe the more complicated field behavior associated with higher order phase catastrophes and therefore a new set of uniform reflection and first-order edge diffraction coefficients is derived. Also, an additional diffraction coefficient associated with a zero-curvature (inflection) point is presented. Higher order effects such as double edge diffraction, creeping waves, and whispering gallery modes are not examined. The extended UTD solution is independent of the scatterer size and also provides useful physical insight into the various scattering and diffraction processes. Its accuracy is confirmed via comparison with some reference moment method results.

Atomistic properties of γ uranium.

PubMed

Beeler, Benjamin; Deo, Chaitanya; Baskes, Michael; Okuniewski, Maria

2012-02-22

The properties of the body-centered cubic γ phase of uranium (U) are calculated using atomistic simulations. First, a modified embedded-atom method interatomic potential is developed for the high temperature body-centered cubic (γ) phase of U. This phase is stable only at high temperatures and is thus relatively inaccessible to first principles calculations and room temperature experiments. Using this potential, equilibrium volume and elastic constants are calculated at 0 K and found to be in close agreement with previous first principles calculations. Further, the melting point, heat capacity, enthalpy of fusion, thermal expansion and volume change upon melting are calculated and found to be in reasonable agreement with experiment. The low temperature mechanical instability of γ U is correctly predicted and investigated as a function of pressure. The mechanical instability is suppressed at pressures greater than 17.2 GPa. The vacancy formation energy is analyzed as a function of pressure and shows a linear trend, allowing for the calculation of the extrapolated zero pressure vacancy formation energy. Finally, the self-defect formation energy is analyzed as a function of temperature. This is the first atomistic calculation of γ U properties above 0 K with interatomic potentials.

Atomistic properties of γ uranium

NASA Astrophysics Data System (ADS)

Beeler, Benjamin; Deo, Chaitanya; Baskes, Michael; Okuniewski, Maria

2012-02-01

The properties of the body-centered cubic γ phase of uranium (U) are calculated using atomistic simulations. First, a modified embedded-atom method interatomic potential is developed for the high temperature body-centered cubic (γ) phase of U. This phase is stable only at high temperatures and is thus relatively inaccessible to first principles calculations and room temperature experiments. Using this potential, equilibrium volume and elastic constants are calculated at 0 K and found to be in close agreement with previous first principles calculations. Further, the melting point, heat capacity, enthalpy of fusion, thermal expansion and volume change upon melting are calculated and found to be in reasonable agreement with experiment. The low temperature mechanical instability of γ U is correctly predicted and investigated as a function of pressure. The mechanical instability is suppressed at pressures greater than 17.2 GPa. The vacancy formation energy is analyzed as a function of pressure and shows a linear trend, allowing for the calculation of the extrapolated zero pressure vacancy formation energy. Finally, the self-defect formation energy is analyzed as a function of temperature. This is the first atomistic calculation of γ U properties above 0 K with interatomic potentials.

Pretransitional diffuse neutron scattering in the mixed perovskite relaxor K1-xLixTaO3

NASA Astrophysics Data System (ADS)

Yong, Grace; Toulouse, Jean; Erwin, Ross; Shapiro, Stephen M.; Hennion, Bernard

2000-12-01

Several previous studies of K1-xLixTaO3 (KLT) have revealed the presence, above the structural transition, of polar nanoregions. Recently, these have been shown to play an essential role in the relaxor behavior of KLT. In order to characterize these regions, we have performed a neutron-scattering study of KLT crystals with different lithium concentrations, both above and below the critical concentration. This study reveals the existence of diffuse scattering that appears upon formation of these regions. The rodlike distribution of the diffuse scattering along cubic directions indicates that the regions form in the shape of discs in the various cubic planes. From the width of the diffuse scattering we extract values for a correlation length or size of the regions as a function of temperature. Finally, on the basis of the reciprocal lattice points around which the diffuse scattering is most intense, we conclude that the regions have tetragonal symmetry. The large increase in Bragg intensities at the first-order transition suggests that the polar regions freeze to form large structural domains and the transition is triggered by the percolation of strain fields through the crystals.

Sedimentation History of Lago Dos Bocas, Puerto Rico, 1942-2005

USGS Publications Warehouse

Soler-López, Luis R.

2007-01-01

The Lago Dos Bocas Dam, located in the municipality of Utuado in north central Puerto Rico, was constructed in 1942 for hydroelectric power generation. The reservoir had an original storage capacity of 37.50 million cubic meters and a drainage area of 440 square kilometers. In 1948, the construction of the Lago Caonillas Dam on the Rio Caonillas branch of Lago Dos Bocas reduced the natural sediment-contributing drainage area to 310 square kilometers; therefore, the Lago Caonillas Dam is considered an effective sediment trap. Sedimentation in Lago Dos Bocas reservoir has reduced the storage capacity from 37.50 million cubic meters in 1942 to 17.26 million cubic meters in 2005, which represents a storage loss of about 54 percent. The long-term annual water-storage capacity loss rate remained nearly constant at about 320,000 cubic meters per year to about 1997. The inter-survey sedimentation rate between 1997 and 1999, however, is higher than the long-term rate at about 1.09 million cubic meters per year. Between 1999 and 2005 the rate is lower than the long-term rate at about 0.13 million cubic meters per year. The Lago Dos Bocas effective sediment-contributing drainage area had an average sediment yield of about 1,400 cubic meters per square kilometer per year between 1942 and 1997. This rate increased substantially by 1999 to about 4,600 cubic meters per square kilometer per year, probably resulting from the historical magnitude floods caused by Hurricane Georges in 1998. Recent data indicate that the Lago Dos Bocas drainage area sediment yield decreased substantially to about 570 cubic meters per square kilometer per year, which is much lower than the 1942-1997 area normalized sedimentation rate of 1,235 cubic meters per square kilometer per year. The impact of Hurricane Georges on the basin sediment yield could have been the cause of this change, since the magnitude of the floods could have nearly depleted the Lago Dos Bocas drainage area of easily erodible and transportable bed sediment. This report summarizes the historical change in water-storage capacity of Lago Dos Bocas between 1942 and 2005.

Enhanced Prophylaxis plus Antiretroviral Therapy for Advanced HIV Infection in Africa.

PubMed

Hakim, James; Musiime, Victor; Szubert, Alex J; Mallewa, Jane; Siika, Abraham; Agutu, Clara; Walker, Simon; Pett, Sarah L; Bwakura-Dangarembizi, Mutsa; Lugemwa, Abbas; Kaunda, Symon; Karoney, Mercy; Musoro, Godfrey; Kabahenda, Sheila; Nathoo, Kusum; Maitland, Kathryn; Griffiths, Anna; Thomason, Margaret J; Kityo, Cissy; Mugyenyi, Peter; Prendergast, Andrew J; Walker, A Sarah; Gibb, Diana M

2017-07-20

In sub-Saharan Africa, among patients with advanced human immunodeficiency virus (HIV) infection, the rate of death from infection (including tuberculosis and cryptococcus) shortly after the initiation of antiretroviral therapy (ART) is approximately 10%. In this factorial open-label trial conducted in Uganda, Zimbabwe, Malawi, and Kenya, we enrolled HIV-infected adults and children 5 years of age or older who had not received previous ART and were starting ART with a CD4+ count of fewer than 100 cells per cubic millimeter. They underwent simultaneous randomization to receive enhanced antimicrobial prophylaxis or standard prophylaxis, adjunctive raltegravir or no raltegravir, and supplementary food or no supplementary food. Here, we report on the effects of enhanced antimicrobial prophylaxis, which consisted of continuous trimethoprim-sulfamethoxazole plus at least 12 weeks of isoniazid-pyridoxine (coformulated with trimethoprim-sulfamethoxazole in a single fixed-dose combination tablet), 12 weeks of fluconazole, 5 days of azithromycin, and a single dose of albendazole, as compared with standard prophylaxis (trimethoprim-sulfamethoxazole alone). The primary end point was 24-week mortality. A total of 1805 patients (1733 adults and 72 children or adolescents) underwent randomization to receive either enhanced prophylaxis (906 patients) or standard prophylaxis (899 patients) and were followed for 48 weeks (loss to follow-up, 3.1%). The median baseline CD4+ count was 37 cells per cubic millimeter, but 854 patients (47.3%) were asymptomatic or mildly symptomatic. In the Kaplan-Meier analysis at 24 weeks, the rate of death with enhanced prophylaxis was lower than that with standard prophylaxis (80 patients [8.9% vs. 108 [12.2%]; hazard ratio, 0.73; 95% confidence interval [CI], 0.55 to 0.98; P=0.03); 98 patients (11.0%) and 127 (14.4%), respectively, had died by 48 weeks (hazard ratio, 0.76; 95% CI, 0.58 to 0.99; P=0.04). Patients in the enhanced-prophylaxis group had significantly lower rates of tuberculosis (P=0.02), cryptococcal infection (P=0.01), oral or esophageal candidiasis (P=0.02), death of unknown cause (P=0.03), and new hospitalization (P=0.03). However, there was no significant between-group difference in the rate of severe bacterial infection (P=0.32). There were nonsignificantly lower rates of serious adverse events and grade 4 adverse events in the enhanced-prophylaxis group (P=0.08 and P=0.09, respectively). Rates of HIV viral suppression and adherence to ART were similar in the two groups. Among HIV-infected patients with advanced immunosuppression, enhanced antimicrobial prophylaxis combined with ART resulted in reduced rates of death at both 24 weeks and 48 weeks without compromising viral suppression or increasing toxic effects. (Funded by the Medical Research Council and others; REALITY Current Controlled Trials number, ISRCTN43622374 .).

Pancreas segmentation from 3D abdominal CT images using patient-specific weighted subspatial probabilistic atlases

NASA Astrophysics Data System (ADS)

Karasawa, Kenichi; Oda, Masahiro; Hayashi, Yuichiro; Nimura, Yukitaka; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Rueckert, Daniel; Mori, Kensaku

2015-03-01

Abdominal organ segmentations from CT volumes are now widely used in the computer-aided diagnosis and surgery assistance systems. Among abdominal organs, the pancreas is especially difficult to segment because of its large individual differences of the shape and position. In this paper, we propose a new pancreas segmentation method from 3D abdominal CT volumes using patient-specific weighted-subspatial probabilistic atlases. First of all, we perform normalization of organ shapes in training volumes and an input volume. We extract the Volume Of Interest (VOI) of the pancreas from the training volumes and an input volume. We divide each training VOI and input VOI into some cubic regions. We use a nonrigid registration method to register these cubic regions of the training VOI to corresponding regions of the input VOI. Based on the registration results, we calculate similarities between each cubic region of the training VOI and corresponding region of the input VOI. We select cubic regions of training volumes having the top N similarities in each cubic region. We subspatially construct probabilistic atlases weighted by the similarities in each cubic region. After integrating these probabilistic atlases in cubic regions into one, we perform a rough-to-precise segmentation of the pancreas using the atlas. The results of the experiments showed that utilization of the training volumes having the top N similarities in each cubic region led good results of the pancreas segmentation. The Jaccard Index and the average surface distance of the result were 58.9% and 2.04mm on average, respectively.

Stochastic series expansion simulation of the t -V model

NASA Astrophysics Data System (ADS)

Wang, Lei; Liu, Ye-Hua; Troyer, Matthias

2016-04-01

We present an algorithm for the efficient simulation of the half-filled spinless t -V model on bipartite lattices, which combines the stochastic series expansion method with determinantal quantum Monte Carlo techniques widely used in fermionic simulations. The algorithm scales linearly in the inverse temperature, cubically with the system size, and is free from the time-discretization error. We use it to map out the finite-temperature phase diagram of the spinless t -V model on the honeycomb lattice and observe a suppression of the critical temperature of the charge-density-wave phase in the vicinity of a fermionic quantum critical point.

On the spectra of Pisot-cyclotomic numbers

NASA Astrophysics Data System (ADS)

Hare, Kevin G.; Masáková, Zuzana; Vávra, Tomáš

2018-07-01

We investigate the complex spectra X^A(β )= \\sum _{j=0}^na_jβ ^j : n\\in N, a_j\\in A where β is a quadratic or cubic Pisot-cyclotomic number and the alphabet A is given by 0 along with a finite collection of roots of unity. Such spectra are discrete aperiodic structures with crystallographically forbidden symmetries. We discuss in general terms under which conditions they possess the Delone property required for point sets modeling quasicrystals. We study the corresponding Voronoi tilings and we relate these structures to quasilattices arising from the cut-and-project method.

Electric field induced cubic to monoclinic phase transition in multiferroic 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Rishikesh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com

2014-10-20

The results of x-ray diffraction studies on 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution poled at various electric fields are presented. After poling, significant value of planar electromechanical coupling coefficient (k{sub P}) is observed for this composition having cubic structure in unpoled state. The cubic structure of 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} transforms to monoclinic structure with space group Pm for the poling field ≥5 kV/cm. Large c-axis microscopic lattice strain (1.6%) is achieved at 30 kV/cm poling field. The variation of the c-axis strain and unit cell volume with poling field shows a drastic jump similar to that observed for strainmore » versus electric field curve in (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3}) O{sub 3}-xPbTiO{sub 3} and (1 − x)Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3}.« less

USGS Streamgages Linked to the Medium Resolution NHD

USGS Publications Warehouse

Stewart, David W.; Rea, Alan; Wolock, David M.

2006-01-01

The locations of approximately 23,000 current and historical U.S. Geological Survey (USGS) streamgages in the United States and Puerto Rico (with the exception of Alaska) have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a hydrologic network that can be used to determine what is upstream or downstream from a point of interest on the NHD network. An automated snapping process made the initial determination of the NHD location of each streamgage. These initial NHD locations were comprehensively reviewed by local USGS personnel to ensure that streamgages were snapped to the correct NHD reaches. About 75 percent of the streamgages snapped to the appropriate NHD reach location initially and 25 percent required adjustment and relocation. This process resulted in approximately 23,000 gages being successfully snapped to the NHD. This dataset contains the latitude and longitude coordinates of the point on the NHD to which the streamgage is snapped and the location of the gage house for each streamgage. A process known as indexing may be used to create reference points (event tables) to the NHD reaches, expressed as a reach code and measure (distance along the reach). Indexing is dependent on the version of NHD to which the indexing is referenced. These data are well suited for use in indexing because nearly all the streamgage NHD locations have been reviewed and adjusted if necessary, to ensure they will index to the appropriate NHD reach. Flow characteristics were computed from the daily streamflow data recorded at each streamgage for the period of record. The flow characteristics associated with each streamgage include: *First date (year, month, day) of streamflow data *Last date (year, month, day) of streamflow data *Number of days of streamflow data *Number of days of non-zero streamflow data *Minimum and maximum daily flow for the period of record (cubic feet per second) *Percentiles (1, 5, 10, 20, 25, 50, 75, 80, 90, 95, 99) of daily flow for the period of record (cubic feet per second) *Average and standard deviation of daily flow for the period of record (cubic feet per second) *Mean annual base-flow index (BFI) computed for the period of record (fraction, ranging from 0 to 1) *Year-to-year standard deviation of the annual base-flow index computed for the period of record (fraction) *Number of years of data used to compute the base-flow index (years) The streamflow data used to compute flow characteristics were copied from the NWIS-Web historical daily discharge archive (nadww01.er.usgs.gov:/www/htdocs/nwisweb/data/discharge) on June 15, 2005.

Group-III elements under high pressure.

NASA Astrophysics Data System (ADS)

Simak, S. I.; Haussermann, U.; Ahuja, R.; Johansson, B.

2000-03-01

At ambient conditions the Group-III elements Ga and In attain unusual open ground-state crystal structures. Recent experiments have discovered that Ga under high pressure transforms into the face-centered (fcc) cubic close-packed structure, while such a transition for In has so far not been observed. We offer a simple explanation for such different behavior based on results from first principles calculations. We predict a so far undiscovered transition of In to the fcc structure at extreme pressures and show that the structure determining mechanism originates from the degree of s-p mixing of the valence orbitals. A unified bonding picture for the Group-III elements is discussed.

Nonlocal dark solitons under competing cubic-quintic nonlinearities.

PubMed

Chen, L; Wang, Q; Shen, M; Zhao, H; Lin, Y-Y; Jeng, C-C; Lee, R-K; Krolikowski, W

2013-01-01

We investigate properties of dark solitons under competing nonlocal cubic-local quintic nonlinearities. Analytical results, based on a variational approach and confirmed by direct numerical simulations, reveal the existence of a unique dark soliton solutions with their width being independent of the degree of nonlocality, due to the competing cubic-quintic nonlinearities.

46 CFR 147.85 - Oxygen.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic feet...

46 CFR 147.85 - Oxygen.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic feet...

46 CFR 147.85 - Oxygen.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic feet...

46 CFR 147.85 - Oxygen.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic feet...

46 CFR 147.85 - Oxygen.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic feet...

Stability of a general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Tianzhou; Rassias, John Michael; Xu Wanxin

2010-09-15

We establish some stability results concerning the general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces. In addition, we establish some results of approximately general mixed additive-cubic mappings in non-Archimedean fuzzy normed spaces. The results improve and extend some recent results.

Cotrimoxazole prophylaxis versus mefloquine intermittent preventive treatment to prevent malaria in HIV-infected pregnant women: two randomized controlled trials.

PubMed

Denoeud-Ndam, Lise; Zannou, Djimon-Marcel; Fourcade, Camille; Taron-Brocard, Clément; Porcher, Raphaël; Atadokpede, Felix; Komongui, Didier G; Dossou-Gbete, Lucien; Afangnihoun, Aldric; Ndam, Nicaise T; Girard, Pierre-Marie; Cot, Michel

2014-02-01

Malaria during pregnancy has serious consequences that are worsened by HIV infection. Malaria preventive measures for HIV-infected pregnant women include cotrimoxazole (CTX) prophylaxis given to prevent HIV-related opportunistic infections and also protective against malaria, or intermittent preventive treatment (IPTp) with an antimalarial drug. Here, we present the first study evaluating CTX efficacy versus mefloquine (MQ)-IPTp, alone and in combination, in HIV-infected pregnant women. We conducted 2 randomized, open-label, noninferiority trials in Benin. In the CTX-mandatory trial, HIV-infected women with CD4 counts of <350 per cubic millimeter received CTX either alone or with MQ-IPTp (N = 292). In the CTX-not-mandatory trial (CD4 count >350/mm), CTX was compared with MQ-IPTp (N = 140). In both the trials, the primary end point was microscopic placental parasitemia. At delivery, 1 woman in each CTX-alone treatment group exhibited placental parasitemia, versus no women in the groups receiving MQ. CTX alone demonstrated noninferiority in the CTX-mandatory trial. However, polymerase chain reaction-detected placental parasitemia was markedly reduced in the CTX + MQ group compared with CTX alone (0/105 vs. 5/103, P = 0.03). Because of insufficient recruitment in the CTX-not-mandatory trial, noninferiority could not be conclusively assessed. Dizziness and vomiting of moderate intensity were reported by 34%-37% of women receiving MQ in both the trials, versus 0%-3% in CTX groups (P < 0.0001). No serious adverse events related to these drugs were found. CTX alone provided adequate protection against malaria in HIV-infected pregnant women, although MQ-IPTp showed higher efficacy against placental infection. Although more frequently associated with dizziness and vomiting, MQ-IPTp may be an effective alternative given concerns about parasite resistance to CTX.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conn, Charlotte E.; Darmanin, Connie; Sagnella, Sharon M.

The dopamine D2 long (D2L) receptor and bacteriorhodopsin (bR), which are integral membraneproteins, have been incorporated within bicontinuous cubic mesophases formed by the lipids anandamide and H-farnesoyl monoethanolamide, which have been specifically investigated by us for use as in mesocrystallization media. We show that the incorporated membraneprotein affects the structure of the cubic phases with the particular effect observed dependent on the geometry of the underlying cubic phase. The results are complementary to those obtained in Part 1 of this series, where we demonstrated that the structural effects observed depend on the structure of the membraneprotein. Importantly protein concentrations commonlymore » used for crystallization can destroy the cubic phase matrix, particularly where there is a large discrepancy between the hydrophilic and the hydrophobic spans of the membraneprotein, and the hydrophilic and hydrophobic domain sizes of the cubic phase.« less

Effective optical path length for tandem diffuse cubic cavities as gas absorption cell

NASA Astrophysics Data System (ADS)

Yu, J.; Gao, Q.; Zhang, Y. G.; Zhang, Z. G.; Wu, S. H.

2014-12-01

Tandem diffuse cubic cavities designed by connecting two single diffuse cubic-shaped cavities, A and B, with an aperture (port fraction fap) in the middle of the connecting baffle was developed as a gas absorption cell. The effective optical path length (EOPL) was evaluated by comparing the oxygen absorption signal in the cavity and in air based on tunable diode laser absorption spectroscopy (TDLAS). Experimental results manifested an enhancement of EOPL for the tandem diffuse cubic cavities as the decrease of fap and can be expressed as the sum of EOPL of two single cubic cavities at fap < 0.01, which coincided well with theoretical analysis. The simulating EOPL was smaller than experimental results at fap > 0.01, which indicated that back scattering light from cavity B to cavity A cannot be ignored at this condition.

Estimation of volume and mass and of changes in volume and mass of selected chat piles in the Picher mining district, Ottawa County, Oklahoma, 2005-10

USGS Publications Warehouse

Smith, S. Jerrod

2013-01-01

From the 1890s through the 1970s the Picher mining district in northeastern Ottawa County, Oklahoma, was the site of mining and processing of lead and zinc ore. When mining ceased in about 1979, as much as 165–300 million tons of mine tailings, locally referred to as “chat,” remained in the Picher mining district. Since 1979, some chat piles have been mined for aggregate materials and have decreased in volume and mass. Currently (2013), the land surface in the Picher mining district is covered by thousands of acres of chat, much of which remains on Indian trust land owned by allottees. The Bureau of Indian Affairs manages these allotted lands and oversees the sale and removal of chat from these properties. To help the Bureau of Indian Affairs better manage the sale and removal of chat, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs, estimated the 2005 and 2010 volumes and masses of selected chat piles remaining on allotted lands in the Picher mining district. The U.S. Geological Survey also estimated the changes in volume and mass of these chat piles for the period 2005 through 2010. The 2005 and 2010 chat-pile volume and mass estimates were computed for 34 selected chat piles on 16 properties in the study area. All computations of volume and mass were performed on individual chat piles and on groups of chat piles in the same property. The Sooner property had the greatest estimated volume (4.644 million cubic yards) and mass (5.253 ± 0.473 million tons) of chat in 2010. Five of the selected properties (Sooner, Western, Lawyers, Skelton, and St. Joe) contained estimated chat volumes exceeding 1 million cubic yards and estimated chat masses exceeding 1 million tons in 2010. Four of the selected properties (Lucky Bill Humbah, Ta Mee Heh, Bird Dog, and St. Louis No. 6) contained estimated chat volumes of less than 0.1 million cubic yards and estimated chat masses of less than 0.1 million tons in 2010. The total volume of all selected chat piles was estimated to be 18.073 million cubic yards in 2005 and 16.171 million cubic yards in 2010. The total mass of all selected chat piles was estimated to be 20.445 ± 1.840 million tons in 2005 and 18.294 ± 1.646 million tons in 2010. All of the selected chat piles decreased in volume and mass for the period 2005 through 2010. Chat piles CP022 (Ottawa property) and CP013 (Sooner property) had some within-property chat-pile redistribution, with both chat piles having net decreases in volume and mass for the period 2005 through 2010. The Sooner property and the St. Joe property had the greatest volume (and mass) changes, with 1.266 million cubic yards and 0.217 million cubic yards (1.432 ± 0.129 million tons and 0.246 ± 0.022 million tons) of chat being removed, respectively. The chat removed from the Sooner and St. Joe properties accounts for about 78 percent of the chat removed from all selected chat piles and properties. The total volume and mass removed from all selected chat piles for the period 2005 through 2010 were estimated to be 1.902 million cubic yards and 2.151 ± 0.194 million tons, respectively.

Aboveground tree biomass on productive forest land in Alaska.

Treesearch

John Yarie; Delbert Mead

1982-01-01

Total aboveground woody biomass of trees on forest land that can produce 1.4 cubic m eters per hectare per year of industrial wood in Alaska is 1.33 billion metric tons green weight. The estimated energy value of the standing woody biomass is 11.9 x 10'5 Btu's. Statewide tables of biomass and energy values for softwoods, hardwoods, and species groups are...

Radiation Dose Assessments for Shore-Based Individuals in Operation Tomodachi, Revision 1

DTIC Science & Technology

2012-12-31

meter (m2) gallon (gal, U.S. liquid) 3.785 412 × 10–3 cubic meter (m3) cubic foot (ft3) 2.831 685 × 10–2 cubic meter (m3) Mass /Density pound (lb...4.535 924 × 10–1 kilogram (kg) atomic mass unit (AMU) 1.660 539 × 10–27 kilogram (kg) pound- mass per cubic foot (lb ft–3) 1.601 846 × 101 kilogram...Ridge, Inc., who provided peer review. • Dr. Mondher Chehata of SAIC who provided technical consultation and critical reviews of environmental

Generalized Vaidya spacetime for cubic gravity

NASA Astrophysics Data System (ADS)

Ruan, Shan-Ming

2016-03-01

We present a kind of generalized Vaidya solution of a new cubic gravity in five dimensions whose field equations in spherically symmetric spacetime are always second order like the Lovelock gravity. We also study the thermodynamics of its spherically symmetric apparent horizon and get its entropy expression and generalized Misner-Sharp energy. Finally, we present the first law and second law hold in this gravity. Although all the results are analogous to those in Lovelock gravity, we in fact introduce the contribution of a new cubic term in five dimensions where the cubic Lovelock term is just zero.

Effect of point defects and disorder on structural phase transitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toulouse, J.

1997-06-01

Since the beginning in 1986, the object of this project has been Structural Phase Transitions (SPT) in real as opposed to ideal materials. The first stage of the study has been centered around the role of Point Defects in SPT`s. Our intent was to use the previous knowledge we had acquired in the study of point defects in non-transforming insulators and apply it to the study of point defects in insulators undergoing phase transitions. In non-transforming insulators, point defects, in low concentrations, marginally affect the bulk properties of the host. It is nevertheless possible by resonance or relaxation methods tomore » study the point defects themselves via their local motion. In transforming solids, however, close to a phase transition, atomic motions become correlated over very large distances; there, even point defects far removed from one another can undergo correlated motions which may strongly affect the transition behavior of the host. Near a structural transition, the elastic properties win be most strongly affected so as to either raise or decrease the transition temperature, prevent the transition from taking place altogether, or simply modify its nature and the microstructure or domain structure of the resulting phase. One of the well known practical examples is calcium-stabilized zirconia in which the high temperature cubic phase is stabilized at room temperature with greatly improved mechanical properties.« less

Pressure-induced superconductivity of arsenic: Evidence for a structural phase transition

NASA Astrophysics Data System (ADS)

Kawamura, H.; Wittig, J.

1985-12-01

The group VB elements P, As, Sb and Bi are normally nonsuperconductors since they are either semiconductors or semimetals at ambient pressure. Under high pressure all of them are turned into superconductors. We have investigated the pressure dependence of Tc for As up to a pressure of 28 GPa quantitatively for the first time. Employing a 3He/ 4He dilution refrigetor we have discovered that Tc increases monotonously and steeply with pressure in the A7-rhombohedral phase from below 0.05 K at 10 GPa to a pronounced maximum at approximately 24 GPa with Tc, max2.7 K. Our results are in strong disagreement with a previous publication. In addition, a faint resistance anomaly is observed in the same pressure range. It is concluded that both phenomena point to the occurence of a structural phase transition in agreement with an unpublished X-ray investigation by another group of authors. The continuous rise of Tc with pressure in the A7 phase is so far a rather rare phenomenon among the B-group elements. Interestingly enough, quite similar behavior has also recently been reported for the A7 phases of P and Sb. We suggest that this unusual feature is related to a pressure-induced phonon softening in connection with a gradual weakening of the covalent bonds. The effect is believed to stand in close connection with the continuous reduction of the rhombohedral distortion of the crystal lattice towards simple cubic with increasing pressure. An interesting prediction for the shape of the melting curve of As at very high pressure can be made.

Assessment of costs and benefits of flexible and alternative fuel use in the US transportation sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1993-01-01

The primary objective of this report is to provide estimates of volumes and development costs of known nonassociated gas reserves in selected, potentially important supplier nations, using a standard set of costing algorithms and conventions. Estimates of undeveloped nonassociated gas reserves and the cost of drilling development wells, production equipment, gas processing facilities, and pipeline construction are made at the individual field level. A discounted cash-flow model of production, investment, and expenses is used to estimate the present value cost of developing each field on a per-thousand-cubic-foot (Mcf) basis. These gas resource cost estimates for individual accumulations (that is, fieldsmore » or groups of fields) then were aggregated into country-specific price-quantity curves. These curves represent the cost of developing and transporting natural gas to an export point suitable for tanker shipments or to a junction with a transmission line. The additional costs of LNG or methanol conversion are not included. A brief summary of the cost of conversion to methanol and transportation to the United States is contained in Appendix D: Implications of Gas Development Costs for Methanol Conversion.« less

Electrochemical characterization of FeMnO3 microspheres as potential material for energy storage applications

NASA Astrophysics Data System (ADS)

Saravanakumar, B.; Ramachandran, S. P.; Ravi, G.; Ganesh, V.; Guduru, Ramesh K.; Yuvakkumar, R.

2018-01-01

In this study, uniform iron manganese trioxide (FeMnO3) microspheres were characterized as electrode for supercapacitor applications. The microspheres were synthesized by hydrothermal method in the presence of different molar ratios of sucrose. X-ray diffraction pattern confirmed that the obtained microsphere has body-centered lattice structure of space group 1213(199). The Raman peak observed at 640 cm-1 might be attributed to the stretching mode of vibration of Mn-O bonds perpendicular to the direction of MnO6 octahedral double chains. The photoluminescence peak at the 536 nm corresponded to Fe2+ ions in FeMnO3 lattice point of body-centered cubic structure. The characteristic strong infrared (IR) bands observed at 669 cm-1 corresponded to Fe-O stretching. The electrochemical characterization of the obtained FeMnO3 products could be understood by carrying out cyclic voltammeter, electroimpedance spectra, and galvanostatic charging and discharge studies in a three-cell setup that demonstrates the exceptional specific capacitance of 773.5 F g-1 at a scan rate of 10 mV s-1 and 763.4 F g-1 at a current density of 1 A g-1.

Documentation of a groundwater flow model developed to assess groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina

USGS Publications Warehouse

Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

2016-08-31

The U.S. Geological Survey developed a groundwater flow model for the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to northeastern North Carolina as part of a detailed assessment of the groundwater availability of the area and included an evaluation of how these resources have changed over time from stresses related to human uses and climate trends. The assessment was necessary because of the substantial dependency on groundwater for agricultural, industrial, and municipal needs in this area.The three-dimensional, groundwater flow model developed for this investigation used the numerical code MODFLOW–NWT to represent changes in groundwater pumping and aquifer recharge from predevelopment (before 1900) to future conditions, from 1900 to 2058. The model was constructed using existing hydrogeologic and geospatial information to represent the aquifer system geometry, boundaries, and hydraulic properties of the 19 separate regional aquifers and confining units within the Northern Atlantic Coastal Plain aquifer system and was calibrated using an inverse modeling parameter-estimation (PEST) technique.The parameter estimation process was achieved through history matching, using observations of heads and flows for both steady-state and transient conditions. A total of 8,868 annual water-level observations from 644 wells from 1986 to 2008 were combined into 29 water-level observation groups that were chosen to focus the history matching on specific hydrogeologic units in geographic areas in which distinct geologic and hydrologic conditions were observed. In addition to absolute water-level elevations, the water-level differences between individual measurements were also included in the parameter estimation process to remove the systematic bias caused by missing hydrologic stresses prior to 1986. The total average residual of –1.7 feet was normally distributed for all head groups, indicating minimal bias. The average absolute residual value of 12.3 feet is about 3 percent of the total observed water-level range throughout the aquifer system.Streamflow observation data of base flow conditions were derived for 153 sites from the U.S. Geological Survey National Hydrography Dataset Plus and National Water Information System. An average residual of about –8 cubic feet per second and an average absolute residual of about 21 cubic feet per second for a range of computed base flows of about 417 cubic feet per second were calculated for the 122 sites from the National Hydrography Dataset Plus. An average residual of about 10 cubic feet per second and an average absolute residual of about 34 cubic feet per second were calculated for the 568 flow measurements in the 31 sites obtained from the National Water Information System for a range in computed base flows of about 1,141 cubic feet per second.The numerical representation of the hydrogeologic information used in the development of this regional flow model was dependent upon how the aquifer system and simulated hydrologic stresses were discretized in space and time. Lumping hydraulic parameters in space and hydrologic stresses and time-varying observational data in time can limit the capabilities of this tool to simulate how the groundwater flow system responds to changes in hydrologic stresses, particularly at the local scale.

40 CFR 49.137 - Rule for air pollution episodes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... continue or reoccur over the next 24 hours. (A) Particulate matter (PM10): 350 micrograms per cubic meter, 24-hour average; (B) Carbon monoxide (CO): 17 milligrams per cubic meter (15 ppm), 8-hour average; (C) Sulfur dioxide (SO2): 800 micrograms per cubic meter (0.3 ppm), 24-hour average; (D) Ozone (O3): 400...

40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

Code of Federal Regulations, 2010 CFR

2010-07-01

... from a designated facility is 400 micrograms per dry standard cubic meter, corrected to 7 percent... discharged to the atmosphere from a designated facility is 27 milligrams per dry standard cubic meter... standard cubic meter, corrected to 7 percent oxygen. (ii) [Reserved] (iii) The emission limit for opacity...