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Sample records for crystal parameter analysis

  1. Liquid crystal parameter analysis for tunable photonic bandgap fiber devices

    DEFF Research Database (Denmark)

    Weirich, Johannes; Lægsgaard, Jesper; Wei, Lei;

    2010-01-01

    We investigate the tunability of splay-aligned liquid crystals for the use in solid core photonic crystal fibers. Finite element simulations are used to obtain the alignment of the liquid crystals subject to an external electric field. By means of the liquid crystal director field the optical per...

  2. Use of three-dimensional parameters in the analysis of crystal structures under compression

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci

    2007-01-01

    Volume-related parameters of atomic coordinations are an important tool for the analysis of structural changes. Unlike usual tables of bond distances and angles they directly depict three-dimensional properties of coordination polyhedra, and in many instances give more profound structural...... information. Accurate determination of atomic coordinations is difficult in cases where a clear bond gap does not exist. In such instances the most reliable existing method is the determination of atomic domains in electron density, which can be performed even for experimental high-pressure crystal structure...... that completely describe distortions of coordinations are the eccentricity, the asphericity Calculation of volumes of coordination polyhedra of any shape and their standard deviations can be programmed using the general expression for the volume of a tetrahedron based on the orthogonal coordinates of its vertices...

  3. Parameter analysis of a photonic crystal fiber with raised-core index profile based on effective index method

    Institute of Scientific and Technical Information of China (English)

    Faramarz E. Seraji; Mahnaz Rashidi; Vajieh Khasheie

    2006-01-01

    @@ Photonic crystal fibers (PCFs) with a stepped raised-core profile and one layer equally spaced holes in the cladding are analyzed. Using effective index method and considering a raised step refractive index difference between the index of the core and the effective index of the cladding, we improve the characteristic parameters such as numerical aperture and V-parameter, and reduce its bending loss to about one tenth of a conventional PCF. Implementing such a structure in PCFs may be one step forward to achieve low loss PCFs for communication applications.

  4. Identification Trial of Crystallization Parameters of Modified Chromium Cast Iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2007-07-01

    Full Text Available In the paper results of researches of abrasion-resisting chromium cast iron inoculated with boron carbide B4C primary crystallization are presented. The main aim of work was make an attempt to identification of crystallization parameters that changed in reason of inoculation. Essential primary crystallization parameters, with the help of which, will be possible to evaluate the inoculation capacity were searched. It was found that in the result of inoculant actions characteristic temperatures were changed and time of primary crystallization was decreased. For tests the new broadened Derivative Thermal Analysis method, in which three samples with different solidification module were applied, was used. Thanks to this inoculation capacity in casts with significant diversified self-cooling ranges was possible to observe.

  5. THERMODYNAMIC PARAMETERS OF LEAD SULFIDE CRYSTALS IN THE CUBIC PHASE

    Directory of Open Access Journals (Sweden)

    T. O. Parashchuk

    2016-07-01

    Full Text Available Geometric and thermodynamic parameters of cubic PbS crystals were obtained using the computer calculations of the thermodynamic parameters within density functional theory method DFT. Cluster models for the calculation based on the analysis of the crystal and electronic structure. Temperature dependence of energy ΔE and enthalpy ΔH, Gibbs free energy ΔG, heat capacity at constant pressure CP and constant volume CV, entropy ΔS were determined on the basis of ab initio calculations of the crystal structure of molecular clusters. Analytical expressions of temperature dependences of thermodynamic parameters which were approximated with quantum-chemical calculation points have been presented. Experimental results compared with theoretically calculated data.

  6. Solid state parameters, structure elucidation, High Resolution X-Ray Diffraction (HRXRD), phase matching, thermal and impedance analysis on L-Proline trichloroacetate (L-PTCA) NLO single crystals.

    Science.gov (United States)

    Kalaiselvi, P; Raj, S Alfred Cecil; Jagannathan, K; Vijayan, N; Bhagavannarayana, G; Kalainathan, S

    2014-11-11

    Nonlinear optical single crystal of L-Proline trichloroacetate (L-PTCA) was successfully grown by Slow Evaporation Solution Technique (SEST). The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm the structure. From the single crystal XRD data, solid state parameters were determined for the grown crystal. The crystalline perfection has been evaluated using high resolution X-ray diffractometer. The frequencies of various functional groups were identified from FTIR spectral analysis. The percentage of transmittance was obtained from UV Visible spectral analysis. TGA-DSC measurements indicate the thermal stability of the crystal. The dielectric constant, dielectric loss and ac conductivity were measured by the impedance analyzer. The DC conductivity was calculated by the cole-cole plot method.

  7. Effect of process parameters on crystal size and morphology of lactose in ultrasound-assisted crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Patel, S.R.; Murthy, Z.V.P. [Chemical Engineering Department, S.V. National Institute of Technology, Surat - 395 007, Gujarat (India)

    2011-03-15

    {alpha}-lactose monohydrate is widely used as a pharmaceutical excipient. Drug delivery system requires the excipient to be of narrow particle size distribution with regular particle shape. Application of ultrasound is known to increase or decrease the growth rate of certain crystal faces and controls the crystal size distribution. In the present paper, effect of process parameters such as sonication time, anti-solvent concentration, initial lactose concentration and initial pH of sample on lactose crystal size, shape and thermal transition temperature was studied. The parameters were set according to the L{sub 9}-orthogonal array method at three levels and recovered lactose from whey by sonocrystallization. The recovered lactose was analyzed by particle size analyzer, scanning electron microscopy and differential scanning calorimeter. It was found that the morphology of lactose crystal was rod/needle like shape. Crystal size distribution of lactose was observed to be influenced by different process parameters. From the results of analysis of variance, the sonication time interval was found to be the most significant parameter affecting the volume median diameter of lactose with the highest percentage contribution (74.28%) among other parameters. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Analysis of liquid crystal properties for photonic crystal fiber devices

    DEFF Research Database (Denmark)

    Weirich, Johannes; Lægsgaard, Jesper; Wei, Lei

    2009-01-01

    We analyze the bandgap structure of Liquid Crystal infiltrated Photonic Crystal Fibers depending on the parameters of the Liquid Crystals by means of finite element simulations. For a biased Liquid Crystal Photonic Crystal Fiber, we show how the tunability of the bandgap position depends...... on the Liquid Crystal parameters....

  9. Crystal growth and structural analysis of zirconium sulphoselenide single crystals

    Indian Academy of Sciences (India)

    K R Patel; R D Vaidya; M S Dave; S G Patel

    2008-08-01

    A series of zirconium sulphoselenide (ZrSSe3–, where = 0, 0.5, 1, 1.5, 2, 2.5, 3) single crystals have been grown by chemical vapour transport technique using iodine as a transporting agent. The optimum condition for the growth of these crystals is given. The stoichiometry of the grown crystals were confirmed on the basis of energy dispersive analysis by X-ray (EDAX) and the structural characterization was accomplished by X-ray diffraction (XRD) studies. The crystals are found to possess monoclinic structure. The lattice parameters, volume, particle size and X-ray density have been carried out for these crystals. The effect of sulphur proportion on the lattice parameter, unit cell volume and X-ray density in the series of ZrSSe3– single crystals have been studied and found to decrease in all these parameters with rise in sulphur proportion. The grown crystals were examined under optical zoom microscope for their surface topography study. Hall effect measurements were carried out on grown crystals at room temperature. The negative value of Hall coefficient implies that these crystals are -type in nature. The conductivity is found to decrease with increase of sulphur content in the ZrSSe3– series. The electrical resistivity parallel to c-axis as well as perpendicular to -axis have been carried out in the temperature range 303–423 K. The results obtained are discussed in detail.

  10. Analysis of liquid crystal properties for photonic crystal fiber devices

    DEFF Research Database (Denmark)

    Weirich, Johannes; Lægsgaard, Jesper; Wei, Lei;

    2009-01-01

    We analyze the bandgap structure of Liquid Crystal infiltrated Photonic Crystal Fibers depending on the parameters of the Liquid Crystals by means of finite element simulations. For a biased Liquid Crystal Photonic Crystal Fiber, we show how the tunability of the bandgap position depends on the L...

  11. The Effect of Solution Parameters on Lysozyme Nucleation Rates and Crystal Quality

    Science.gov (United States)

    Judge, R. A.; Snell, E. H.

    1998-01-01

    In the pursuit of strongly diffracting high quality macromolecule crystals of suitable volume, this study investigates how the formation of macromolecules in solution and their growth characteristics effect crystal volume and diffracting quality. We systematically investigated the effect of solution conditions on lysozyme nucleation rates and the volume of crystals produced. Batch crystallization plates were used in combination with a video microscope system to measure nucleation rates and crystal volume. As expected from classical nucleation theory, crystal numbers were found to increase with increases in temperature and supersaturation. Small changes in solution pH, at constant supersaturation values were found, however, to dramatically effect the number of crystals nucleated in the wells varying from 1000s to 10s in the pH range 4.0 to 5.2. Having optimized the conditions required to produce an appropriate number of crystals of a suitable volume for X-ray analysis, a large number of uniform crystals were produced under exactly the same conditions. In the X-ray analysis of more than 50 such crystals there was found a wide variation in crystal lattice parameters and data quality. The variation in X-ray quality crystal samples is thought to be related to the growth rate variation caused by growth rate dispersion seen in lysozyme crystal growth experiments.

  12. The lattice parameter of highly pure silicon single crystals

    Science.gov (United States)

    Becker, P.; Scyfried, P.; Siegert, H.

    1982-08-01

    From crystal to crystal comparison, the d 220 lattice spacing in PERFX and WASO silicon crystals used in the only two existing absolute measurements have been found to be equal within ±2×10-7 d 220. This demonstrates that generic variabilities of the two crystals account only for a small part of the 1.8×10-6 d 220 difference in the two absolute measurements. In a new series of 336 single measurements, our d 220 value reported recently has been confirmed within ±2×10-8 d 220. From these results we derive the following lattice parameter for highly pure silicon single crystals: a 0=(543 102.018±0.034) fm (at 22.5°C, in vacuum).

  13. INFLUENCE OF PARAMETERS OF CRYSTALLIZATION ON MODIFYING OF AN ALLOY

    Directory of Open Access Journals (Sweden)

    V. Yu. Stetsenko

    2015-01-01

    Full Text Available It is shown that extent of modifying of an alloy is proportional to overcooling at its hardening, viscosity of fusion and interphase superficial energy of crystals of the leading phase. The key technological parameters of modifying of an alloy are the speed of its hardening, viscosity of fusion and extent of refinement from surface-active elements. Their adsorption on crystals of the leading phase interferes with modifying of an alloy.

  14. Supersymmetry Parameter Analysis

    CERN Document Server

    Kalinowski, Jan

    2002-01-01

    Supersymmetric particles can be produced copiously at future colliders. From the high-precision data taken at e+e- linear colliders, TESLA in particular, and combined with results from LHC, and CLIC later, the low-energy parameters of the supersymmetric model can be determined. Evolving the parameters from the low-energy scale to the high-scale by means of renormalization group techniques the fundamental supersymmetry parameters at the high scale, GUT or Planck, can be reconstructed to reveal the origin of supersymmetry breaking.

  15. Photoelastic sphenoscopic analysis of crystals

    Energy Technology Data Exchange (ETDEWEB)

    Montalto, L. [DIISM, Dip. Di Ingegneria Industriale e Scienze Matematiche—Università Politecnica delle Marche, Ancona (Italy); SIMAU, Dip. Di Scienze e Ingegneria della Materia, dell’ambiente ed Urbanistica—Università Politecnica delle Marche, Ancona (Italy); Rinaldi, D. [SIMAU, Dip. Di Scienze e Ingegneria della Materia, dell’ambiente ed Urbanistica—Università Politecnica delle Marche, Ancona (Italy); Scalise, L.; Paone, N. [DIISM, Dip. Di Ingegneria Industriale e Scienze Matematiche—Università Politecnica delle Marche, Ancona (Italy); Davì, F. [DICEA, Dip. Di Ingegneria Civile, Edile e Architettura—Università Politecnica delle Marche, Ancona (Italy)

    2016-01-15

    Birefringent crystals are at the basis of various devices used in many fields, from high energy physics to biomedical imaging for cancer detection. Since crystals are the main elements of those devices, a great attention is paid on their quality and properties. Here, we present a methodology for the photoelastic analysis of birefringent crystals, based on a modified polariscope. Polariscopes using conoscopic observation are used to evaluate crystals residual stresses in a precise but time consuming way; in our methodology, the light beam shape, which impinges on the crystal surface, has been changed from a solid cone (conoscopy) to a wedge (sphenoscopy). Since the polarized and coherent light is focused on a line rather than on a spot, this allows a faster analysis which leads to the observation, at a glance, of a spatial distribution of stress along a line. Three samples of lead tungstate crystals have been observed using this technique, and the obtained results are compared with the conoscopic observation. The samples have been tested both in unloaded condition and in a loaded configuration induced by means of a four points bending device, which allows to induce a known stress distribution in the crystal. The obtained results confirm, in a reliable manner, the sensitivity of the methodology to the crystal structure and stress.

  16. Crystal Field Parameters and Phase Transitions in ErSb

    DEFF Research Database (Denmark)

    Shapiro, S. M.; Bak, P.

    1975-01-01

    The crystal field levels of the Er ion in a single crystal of ErSb have been measured by inelastic neutron scattering. The crystal field parameters obtained by a least squares fit to the spectra at several temperatures are: B4 = (0·473 ± 0·005) × 10−2°K and B6 = (0·59 ± 0·06) × 10−5°K, which differ...... considerably from the values o by interpolation from measurements on other compounds. In addition the temperature dependence of the magnetic scattering in the vicinity of the Néel temperature (TN = 3·55°K) clearly demonstrates that the transition is second order in contrast to the first order behavior...

  17. Thermal kinetic and dielectric parameters of acenaphthene crystal grown by vertical Bridgman technique

    Science.gov (United States)

    Karuppusamy, S.; Dinesh Babu, K.; Nirmal Kumar, V.; Gopalakrishnan, R.

    2016-05-01

    The bulk acenaphthene crystal was grown in a single-wall ampoule by vertical Bridgman technique. X-ray diffraction analysis confirmed the orthorhombic crystal system of title compound with space group Pcm21. Thermal behavior of compound was studied using thermogravimetry—differential scanning calorimetry analysis. Thermal kinetic parameters like activation energy, frequency factor, Avrami exponent, reaction rate and degree of conversion were calculated using Kissingers and Ozawa methods under non-isothermal condition for acenaphthene crystal and reported for the first time. The calculated thermal kinetic parameters are presented. Dielectric studies were performed to calculate the dielectric parameters such as dielectric constant, dielectric loss, AC conductivity, and activation energy from Arrhenius plot.

  18. Physicochemical parameters of crystallization of dunite from the Guli ultrabasic massif (Maimecha Kotui province)

    Science.gov (United States)

    Simonov, V. A.; Vasiliev, Yu. R.; Stupakov, S. I.; Kotlyarov, A. V.; Karmanov, N. S.

    2015-09-01

    On the basis of analysis of molten inclusions in chrome-spinelide, physicochemical parameters of dunite crystallization were defined. Experimental, analytical studies directly indicate that dunite was formed from high-temperature melts close in petrochemical composition and high-temperature characteristics to meimechite magmas. Successive evolution of magmatic systems compositions in a course of intra-chamber crystallization of dunite was established: from picriteâ "meimechite (with olivine formation at 1590-1415°C and chrome-spinelide crystallization at 1405-1365°C) to picrate-basalt and basalt.

  19. Coefficient of crystal lattice matching as a parameter of substrate - crystal structure compatibility in silumins

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2009-07-01

    Full Text Available Adding high-melting point elements (Mo, Nb, Ni, Ti, W to complex silumins results in hardening of the latter ones, owing to the formation of new intermetallic phases of the AlxMey type, with refinement of dendrites in α solution and crystals in β phase. The hardening is also due to the effect of various inoculants. An addition of the inoculant is expected to form substrates, the crystal lattice of which, or some (privileged lattice planes and interatomic spaces should bear a strong resemblance to the crystal nucleus. To verify this statement, using binary phase equilibria systems, the coefficient of crystal lattice matching, being one of the measures of the crystallographic similarity, was calculated. A compatibility of this parameter (up to 20% may decide about the structure compatibility between the substrate and crystal which, in turn, is responsible for the effectiveness of alloy modification. Investigations have proved that, given the temperature range of their formation, the density, the lattice type, and the lattice parameter, some intermetallic phases of the AlxMey type can act as substrates for the crystallisation of aluminium and silicon, and some of the silumin hardening phases.

  20. Optimization of process parameters by Taguchi robust design method for the development of nano-crystals of sirolimus using sonication based crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, P.J.; Murthy, Z.V.P. [Chemical Engineering Department, S.V. National Institute of Technology, Surat, Gujarat (India); Pati, R.K. [Quantitative Methods and Operations Management, Indian Institute of Management, Kozhikode, Kerala (India)

    2012-01-15

    Taguchi method is widely used by the engineers and researchers across the globe for optimization of process parameters in view of cost, economy and time. Ultrasound based sonication process was used for deriving the nano-crystals of sirolimus in a narrow range. Seven critical process parameters with three levels were optimized with L{sub 18} array design. Crystal size analysis with its zeta potential measured and found that the crystals derived are stable in nature. Also SEM analysis carried out to know size and shape of the crystals and found that the crystals obtained are spherical in nature. Purity of the crystals derived checked with the help of melting point, TLC and HPLC procedures. Characterization of nano-crystals made with Fourier transform infrared spectroscopy and X-ray diffraction analysis. Correlation between the zeta potential and crystal size has been established with the help of scientific and statistical methods. Detailed statistical analysis such as t -test, regression and descriptive statistics of the results has been carried out to explore further information and interactions of process parameters. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Large-lattice-parameter perovskite single-crystal substrates

    Science.gov (United States)

    Uecker, Reinhard; Bertram, Rainer; Brützam, Mario; Galazka, Zbigniew; Gesing, Thorsten M.; Guguschev, Christo; Klimm, Detlef; Klupsch, Michael; Kwasniewski, Albert; Schlom, Darrell G.

    2017-01-01

    The pseudobinary system LaLuO3-LaScO3 was explored in hopes of discovering new perovskite-type substrates with pseudocubic lattice parameters above 4 Å. A complete solid solution of the type (LaLuO3)1-x(LaScO3)x forms between the end members LaLuO3 and LaScO3, enabling large single crystals of (LaLuO3)1-x(LaScO3)x to be grown from the melt. A single crystal with x≈0.34 was demonstrated. Considering the maximum thermal load of the iridium crucibles appropriate for Czochralski growth of this solid solution, the theoretically maximum achievable x-value is 0.67. Based on the phase diagram determined, it is anticipated that single crystals with pseudocubic lattice constants between 4.09 and 4.18 Å can be grown in this system by the Czochralski method.

  2. Understanding bibliometric parameters and analysis.

    Science.gov (United States)

    Choudhri, Asim F; Siddiqui, Adeel; Khan, Nickalus R; Cohen, Harris L

    2015-01-01

    Bibliometric parameters have become an important part of modern assessment of academic productivity. These parameters exist for the purpose of evaluating authors (publication count, citation count, h-index, m-quotient, hc-index, e-index, g-index, i-10 [i-n] index) and journals (impact factor, Eigenfactor, article influence score, SCImago journal rank, source-normalized impact per paper). Although in recent years there has been a proliferation of bibliometric parameters, the true meaning and appropriate use of these parameters is generally not well understood. Effective use of existing and emerging bibliometric tools can aid in assessment of academic productivity, including readiness for promotions and other awards. However, if not properly understood, the data can be misinterpreted and may be subject to manipulation. Familiarity with bibliometric parameters will aid in their effective implementation in the review of authors-whether individuals or groups-and journals, as well as their possible use in the promotions review process, maximizing the effectiveness of bibliometric analysis.

  3. Crystal nucleation as the ordering of multiple order parameters

    Science.gov (United States)

    Russo, John; Tanaka, Hajime

    2016-12-01

    Nucleation is an activated process in which the system has to overcome a free energy barrier in order for a first-order phase transition between the metastable and the stable phases to take place. In the liquid-to-solid transition, the process occurs between phases of different symmetry, and it is thus inherently a multi-dimensional process, in which all symmetries are broken at the transition. In this Focus Article, we consider some recent studies which highlight the multi-dimensional nature of the nucleation process. Even for a single-component system, the formation of solid crystals from the metastable melt involves fluctuations of two (or more) order parameters, often associated with the decoupling of positional and orientational symmetry breaking. In other words, we need at least two order parameters to describe the free-energy of a system including its liquid and crystalline states. This decoupling occurs naturally for asymmetric particles or directional interactions, focusing here on the case of water, but we will show that it also affects spherically symmetric interacting particles, such as the hard-sphere system. We will show how the treatment of nucleation as a multi-dimensional process has shed new light on the process of polymorph selection, on the effect of external fields on the nucleation process and on glass-forming ability.

  4. Framework for the analysis of crystallization operations

    DEFF Research Database (Denmark)

    Meisler, Kresten Troelstrup; Abdul Samad, Noor Asma Fazli Bin; Gernaey, Krist

    Crystallization is often applied in the production of salts and/oractive pharmaceutical ingredients (API), and the crystallization step is an essential part of the manufacturing process for many chemicals-based products.In recent years the monitoring and analysis of crystallization operations has...

  5. Crystal structure analysis of intermetallic compounds

    Science.gov (United States)

    Conner, R. A., Jr.; Downey, J. W.; Dwight, A. E.

    1968-01-01

    Study concerns crystal structures and lattice parameters for a number of new intermetallic compounds. Crystal structure data have been collected on equiatomic compounds, formed between an element of the Sc, Ti, V, or Cr group and an element of the Co or Ni group. The data, obtained by conventional methods, are presented in an easily usable tabular form.

  6. Spectral, mechanical, thermal, optical and solid state parameters, of metal-organic bis(hydrogenmaleate)-CO(II) tetrahydrate crystal

    Science.gov (United States)

    Chandran, Senthilkumar; Jagan, R.; Paulraj, Rajesh; Ramasamy, P.

    2015-10-01

    Metal-organic bis(hydrogenmaleate)-Co(II) tetrahydrate single crystals have been grown by slow evaporation solution growth technique at room temperature. The crystal structure and the unit cell parameters were analyzed from the X-ray diffraction studies. Single-crystal X-ray diffraction analyses reveal that the grown crystal belongs to triclinic system with the space group P-1. Functional groups in bis(hydrogenmaleate)-Co(II) tetrahydrate were identified by Fourier transform infrared spectral analysis. The peak observed at 663 cm-1 is assigned to the (Co-O) stretching vibrations. The optical transmission of the crystal was studied by UV-vis-NIR spectral analysis. The photoluminescence emission studies were carried out for the title compound in a wide wavelength range between 350 nm and 550 nm at 303 K. Mechanical strength was tested by Vickers microhardness test. The laser damage threshold value has been determined using Nd:YAG laser operating at 1064 nm. At various frequencies and temperatures the dielectric behavior of the material was investigated. Solid state parameters such as plasma energy, Penn gap, Fermi energy and electronic polarizability were evaluated. Photoconductivity measurements were carried out for the grown crystal in the presence of DC electric field at room temperature. Thermal stability and decomposition of the crystal were studied by TG-DTA. The weight loss of the title compound occurs in different steps.

  7. Crystallization and preliminary crystallographic analysis of recombinant human galectin-1

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Stacy A. [Institute for Glycomics, Gold Coast Campus, Griffith University, Queensland 4222 (Australia); Scott, Ken [School of Biological Sciences, University of Auckland, Auckland (New Zealand); Blanchard, Helen, E-mail: h.blanchard@griffith.edu.au [Institute for Glycomics, Gold Coast Campus, Griffith University, Queensland 4222 (Australia)

    2007-11-01

    Human galectin-1 has been cloned, expressed in E. coli, purified and crystallized in the presence of both lactose (ligand) and β-mercaptoethanol under six different conditions. The X-ray diffraction data obtained have enabled the assignment of unit-cell parameters for two novel crystal forms of human galectin-1. Galectin-1 is considered to be a regulator protein as it is ubiquitously expressed throughout the adult body and is responsible for a broad range of cellular regulatory functions. Interest in galectin-1 from a drug-design perspective is founded on evidence of its overexpression by many cancers and its immunomodulatory properties. The development of galectin-1-specific inhibitors is a rational approach to the fight against cancer because although galectin-1 induces a plethora of effects, null mice appear normal. X-ray crystallographic structure determination will aid the structure-based design of galectin-1 inhibitors. Here, the crystallization and preliminary diffraction analysis of human galectin-1 crystals generated under six different conditions is reported. X-ray diffraction data enabled the assignment of unit-cell parameters for crystals grown under two conditions, one belongs to a tetragonal crystal system and the other was determined as monoclinic P2{sub 1}, representing two new crystal forms of human galectin-1.

  8. Framework for the analysis of crystallization operations

    DEFF Research Database (Denmark)

    Meisler, Kresten Troelstrup; Abdul Samad, Noor Asma Fazli Bin; Gernaey, Krist

    received increased attention due to the growing need to control more sophisticated production lines as well asto measure/monitor the final product characteristics. Crystallization operations involve a combination of several phenomena, and different kinetic models are required for their modeling. Growth......Crystallization is often applied in the production of salts and/oractive pharmaceutical ingredients (API), and the crystallization step is an essential part of the manufacturing process for many chemicals-based products.In recent years the monitoring and analysis of crystallization operations has...... of the crystals occurs in multiple dimensions and the relative rates of different growth and other kinetic phenomena control the shape and size distribution of the final product. Including several dimensions in the crystallization will allow a more general description of the kinetic phenomena...

  9. Effect of Electrostatic Reduced-Gravity Environment on the Crystallographic Parameters of elt-Crystallized Polypropylene

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An electrostatic reduced-gravity device was developed and used specially for the study of the melt crystal-lization of polypropylene. The crystal structure of melt-crystallized polypropylene prepared under the reduced-gravityenvironment was investigated by using X-ray diffraction. The experiment results show that the crystal structure ofthe polypropylene is strongly dependent on the gravity applied to the sample during solidification. It is found that thecrystallographic parameters a and b increase markedly with reduced-gravity ratio, while the value of c increasesmildly.

  10. Optimization of control parameters of CdZnTe ACRT-Bridgman single crystal growth

    Institute of Scientific and Technical Information of China (English)

    LIU Juncheng

    2004-01-01

    The CdZnTe vertical Bridgman single crystal process with accelerated crucible rotation technique (ACRT) has been simulated. Effects have been investigated of the ACRT wave parameters on the solid-liquid interface concavity and the solute segregation of the crystal. The results show that ACRT can result in the increase of both the solid-liquid interface concavity and the temperature gradient of the melt in the front of the solid-liquid interface, of which the magnitude varies from small to many times when the ACRT wave parameters change. Of the ACRT wave parameters, the increase of the crucible maximum rotation rate can hardly improve the radial solute segregation of the crystal, but the variation of the crucible acceleration time, the keep time at the maximum rotation rate, and the crucible deceleration time can affect the solute segregation of the single crystal extraordinarily. With suitable wave parameters, ACRT greatly decreases the radial solute segregation of the crystal, and even makes it disappear completely. However, it increases both the axial solute segregation and the radial one notably with bad wave parameters. An excellent single crystal could be gotten, of which a majority part is with no segregation, with ACRT-Bridgman method by adjusting both the ACRT wave parameters and the crystal growth control parameters, such as the initial temperature of the melt, the temperature gradient, and the crucible withdrawal rate, etc.

  11. Crystal imperfections and Mott parameters of sprayed nanostructure IrO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hassanien, A.S., E-mail: a.s.hassanien@gmail.com [Engineering Mathematics and Physics Department, Faculty of Engineering (Shoubra), Benha University (Egypt); Physics Department, Faculty of Science in Ad-Dawadmi, Shaqra University, 11911 (Saudi Arabia); Akl, Alaa A. [Physics Department, Faculty of Science in Ad-Dawadmi, Shaqra University, 11911 (Saudi Arabia)

    2015-09-15

    Nano-crystalline iridium oxide thin films were obtained by a spray pyrolysis technique onto preheated glass substrates. X-ray diffraction reveals that IrO{sub 2} thin films were polycrystalline in the rutile structure with primitive tetragonal lattice and its preferential orientation were along the 〈110〉 and 〈101〉 directions. X-ray diffraction line profile analysis (XRDLPA) was used to assign microstructure and crystal imperfections of IrO{sub 2} thin films. Some important parameters such as crystallite size, microstrain, average residual stress, number of crystallite/cm{sup 2} and dislocation density were studied. The effects of deposition temperatures and solution concentrations on the microstructural and crystal defects were discussed. All estimated values were found to be dependent upon the growth parameters. Mott parameters, trapping state energy and potential barrier were investigated and studied for a defined thin film sample. This sample was selected because it has the suitable conditions for electrochromic applications.

  12. Spectral, mechanical, thermal, optical and solid state parameters, of metal-organic bis(hydrogenmaleate)-CO(II) tetrahydrate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Chandran, Senthilkumar [Centre for Crystal Growth, Department of Physics, SSN College of Engineering, Kalavakkam 603110 (India); Jagan, R. [Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India); Paulraj, Rajesh, E-mail: rajeshp@ssn.edu.in [Centre for Crystal Growth, Department of Physics, SSN College of Engineering, Kalavakkam 603110 (India); Ramasamy, P. [Centre for Crystal Growth, Department of Physics, SSN College of Engineering, Kalavakkam 603110 (India)

    2015-10-15

    Metal-organic bis(hydrogenmaleate)-Co(II) tetrahydrate single crystals have been grown by slow evaporation solution growth technique at room temperature. The crystal structure and the unit cell parameters were analyzed from the X-ray diffraction studies. Single-crystal X-ray diffraction analyses reveal that the grown crystal belongs to triclinic system with the space group P-1. Functional groups in bis(hydrogenmaleate)-Co(II) tetrahydrate were identified by Fourier transform infrared spectral analysis. The peak observed at 663 cm{sup −1} is assigned to the (Co–O) stretching vibrations. The optical transmission of the crystal was studied by UV–vis–NIR spectral analysis. The photoluminescence emission studies were carried out for the title compound in a wide wavelength range between 350 nm and 550 nm at 303 K. Mechanical strength was tested by Vickers microhardness test. The laser damage threshold value has been determined using Nd:YAG laser operating at 1064 nm. At various frequencies and temperatures the dielectric behavior of the material was investigated. Solid state parameters such as plasma energy, Penn gap, Fermi energy and electronic polarizability were evaluated. Photoconductivity measurements were carried out for the grown crystal in the presence of DC electric field at room temperature. Thermal stability and decomposition of the crystal were studied by TG–DTA. The weight loss of the title compound occurs in different steps. - Graphical abstract: Molecular structure of the bis(hydrogenmaleate)-Co(II) tetrahydrate drawn at 40% ellipsoid probability level. - Highlights: • Bis(hydrogenmaleate)-Co(II) tetrahydrate single crystal is grown by slow evaporation method. • Structural and optical properties were discussed. • The title complex crystal is thermally stable up to 91 °C. • Plasma energy, Fermi energy and electronic polarizability are evaluated. • It exhibits positive photoconductivity.

  13. Supersymmetry Parameter Analysis with Fittino

    Energy Technology Data Exchange (ETDEWEB)

    Bechtle, Philip; /SLAC; Desch, Klaus; Wienemann, Peter; /Freiburg U.

    2005-06-24

    We present the results of a realistic global fit of the Lagrangian parameters of the Minimal Supersymmetric Standard Model to simulated data from ILC and LHC with realistic estimates of the observable uncertainties. Higher order radiative corrections are accounted for where ever possible to date. Results are obtained for a modified SPS1a MSSM benchmark scenario but they were checked not to depend critically on this assumption. Exploiting a simulated annealing algorithm, a stable result is obtained without any a priori assumptions on the fit parameters. Most of the Lagrangian parameters can be extracted at the percent level or better if theoretical uncertainties are neglected. Neither LHC nor ILC measurements alone will be sufficient to obtain a stable result. The effects of theoretical uncertainties arising from unknown higher-order corrections and parametric uncertainties are examined qualitatively. They appear to be relevant and the result motivates further precision calculations.

  14. Ecolifter Conceptual Configuration Design and Parameter Analysis

    Institute of Scientific and Technical Information of China (English)

    唐胜景

    2003-01-01

    In the phase of conceptually designing, the Ecolifter with three-lift-surface configuration, the influences of aircraft geometric parameters and configuration such as wing geometric parameters, canard parameters, aircraft center of gravity and engine positions and so on, on flight dynamic stability are discussed with the integrated analysis method. On the basis of the analysis of flight dynamic stability, the suitable wing geometric parameters are given and the improved aircraft configuration is proposed.

  15. Analysis of Hydrogen Bonds in Crystals

    Directory of Open Access Journals (Sweden)

    Sławomir J. Grabowski

    2016-05-01

    Full Text Available The determination of crystal structures provides important information on the geometry of species constituting crystals and on the symmetry relations between them. Additionally, the analysis of crystal structures is so conclusive that it allows us to understand the nature of various interactions. The hydrogen bond interaction plays a crucial role in crystal engineering and, in general, its important role in numerous chemical, physical and bio-chemical processes was the subject of various studies. That is why numerous important findings on the nature of hydrogen bonds concern crystal structures. This special issue presents studies on hydrogen bonds in crystals, and specific compounds and specific H-bonded patterns existing in crystals are analyzed. However, the characteristics of the H-bond interactions are not only analyzed theoretically; this interaction is compared with other ones that steer the arrangement of molecules in crystals, for example halogen, tetrel or pnicogen bonds. More general findings concerning the influence of the hydrogen bond on the physicochemical properties of matter are also presented.

  16. Photonic Crystals Mathematical Analysis and Numerical Approximation

    CERN Document Server

    Dörfler, Willy; Plum, Michael; Schneider, Guido; Wieners, Christian

    2011-01-01

    This book concentrates on the mathematics of photonic crystals, which form an important class of physical structures investigated in nanotechnology. Photonic crystals are materials which are composed of two or more different dielectrics or metals, and which exhibit a spatially periodic structure, typically at the length scale of hundred nanometers. In the mathematical analysis and the numerical simulation of the partial differential equations describing nanostructures, several mathematical difficulties arise, e. g., the appropriate treatment of nonlinearities, simultaneous occurrence of contin

  17. Determination of inconsistency of crystal lattice parameters of. gamma. - and. gamma. '-phases of nickel heat resisting alloys by Fourier-analysis of x-ray diffraction reflex profiles

    Energy Technology Data Exchange (ETDEWEB)

    Samojlov, A.I.; Ignatova, I.A.; Krivko, A.I.; Kozlova, V.S.; Dodonova, L.P.

    1983-01-01

    A method is outlined that enables with the use of Fourier-analysis of summary unresolved X-ray diffraction profile of the matrix ..gamma.. and intermetallic ..gamma..' phases of nickel heat resisting alloys of the Ni-Cr-Co-Al-Ti-Nb-W-Mo-V -Hf system, to calculate the location of reflexes of each phase, that is, to determine the periods of their crystal lattices in the alloy (in monolith) directly without electrolytic separation of ..gamma..'-phase. The limits of the method applicability were determined.

  18. Theoretical explanation of electron paramagnetic resonance and optical parameters for Cu2+ ion in LiNbO3 crystal

    Indian Academy of Sciences (India)

    S Ravi; P Subramanian

    2007-08-01

    The EPR parameters, anisotropic -factors , and for Cu2+ ion and hyperfine structure constants , and for Cu2+ in LiNbO3 crystal are calculated by the method of diagonalizing the full Hamiltonian matrix. The crystal-field parameters contact with the crystal structure by the aid of the superposition model. The optical transition parameters are calculated using Zhao crystal-field model. The calculated results are in good agreement with the observed values. The results are discussed.

  19. Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes.

    Science.gov (United States)

    Samad, Noor Asma Fazli Abdul; Sin, Gürkan; Gernaey, Krist V; Gani, Rafiqul

    2013-11-01

    This paper presents the application of uncertainty and sensitivity analysis as part of a systematic model-based process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty, while for sensitivity analysis, global methods including the standardized regression coefficients (SRC) and Morris screening are used to identify the most significant parameters. The potassium dihydrogen phosphate (KDP) crystallization process is used as a case study, both in open-loop and closed-loop operation. In the uncertainty analysis, the impact on the predicted output of uncertain parameters related to the nucleation and the crystal growth model has been investigated for both a one- and two-dimensional crystal size distribution (CSD). The open-loop results show that the input uncertainties lead to significant uncertainties on the CSD, with appearance of a secondary peak due to secondary nucleation for both cases. The sensitivity analysis indicated that the most important parameters affecting the CSDs are nucleation order and growth order constants. In the proposed PAT system design (closed-loop), the target CSD variability was successfully reduced compared to the open-loop case, also when considering uncertainty in nucleation and crystal growth model parameters. The latter forms a strong indication of the robustness of the proposed PAT system design in achieving the target CSD and encourages its transfer to full-scale implementation.

  20. Determination of SDI parameters for single crystal AGS

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1999-01-01

    The responses for 1 and 4 AGS detectectors were compared. It was found that 1 detector reacts approximately as 25% of four detectors. Altitude and angle variations follow the same tendensies whether 1 or 4 detectors are used. Kerma rates equations were compared and discussed. Parameters for calcu...... for calculation of SDI air kerma rate (1 m) were calculated for HMS, KNO3 and 137Cs....

  1. Overcoming drug crystallization in electrospun fibers--Elucidating key parameters and developing strategies for drug delivery.

    Science.gov (United States)

    Seif, Salem; Franzen, Lutz; Windbergs, Maike

    2015-01-15

    For the development of novel therapeutics, uncontrolled crystallization of drugs within delivery systems represents a major challenge. Especially for thin and flexible polymeric systems such as oral films or dermal wound dressings, the formation and growth of drug crystals can significantly affect drug distribution and release kinetics as well as physical storage stability. In this context, electrospinning was introduced as a fabrication technique with the potential to encapsulate drugs within ultrafine fibers by rapid solvent evaporation overcoming drug crystallization during fabrication and storage. However, these effects could so far only be shown for specific drug-polymer combinations and an in-depth understanding of the underlying processes of drug-loaded fiber formation and influencing key parameters is still missing. In this study, we systematically investigated crystal formation of caffeine as a model drug in electrospun fibers comparing different polymers. The solvent polarity was found to have a major impact on the drug crystal formation, whereas only a minor effect was attributed to the electrospinning process parameters. Based on an in-depth understanding of the underlying processes determining drug crystallization processes in electrospun fibers, key parameters could be identified which allow for the rational development of drug-loaded electrospun fibers overcoming drug crystallization.

  2. Kinetics of 12-Hydroxyoctadecanoic Acid SAFiN Crystallization Rationalized Using Hansen Solubility Parameters.

    Science.gov (United States)

    Rogers, Michael A; Marangoni, Alejandro G

    2016-12-06

    Changes in solvent chemistry influenced kinetics of both nucleation and crystallization of 12-hydroxyoctadecenoic, as determined using differential scanning calorimetry and applying a modified Avrami model to the calorimetric data. Altering solvent properties influenced solvent-gelator compatibility, which in turn altered the chemical potential of the system at the onset of crystallization, the kinetics of gelation, and the resulting 12HOA crystal fiber length. The chemical potential at the onset of crystallization was linearly correlated to both the hydrogen-bonding Hansen solubility parameter and the solvent-gelator vectorial distance in Hansen space, Ra. Our work suggests that solvent properties can be modulated to affect the solubility of 12HOA, which in turn influences the kinetics of crystallization and the self-assembly of this organogelator into supramolecular crystalline structures. Therefore, modulation of solvent properties during organogelation can be used to control fiber length and thus engineer the physical properties of the gel.

  3. Influence of precipitating agents on thermodynamic parameters of protein crystallization solutions.

    Science.gov (United States)

    Stavros, Philemon; Saridakis, Emmanuel; Nounesis, George

    2016-09-01

    X-ray crystallography is the most powerful method for determining three-dimensional structures of proteins to (near-)atomic resolution, but protein crystallization is a poorly explained and often intractable phenomenon. Differential Scanning Calorimetry was used to measure the thermodynamic parameters (ΔG, ΔH, ΔS) of temperature-driven unfolding of two globular proteins, lysozyme, and ribonuclease A, in various salt solutions. The mixtures were categorized into those that were conducive to crystallization of the protein and those that were not. It was found that even fairly low salt concentrations had very large effects on thermodynamic parameters. High concentrations of salts conducive to crystallization stabilized the native folded forms of proteins, whereas high concentrations of salts that did not crystallize them tended to destabilize them. Considering the ΔH and TΔS contributions to the ΔG of unfolding separately, high concentrations of crystallizing salts were found to enthalpically stabilize and entropically destabilize the protein, and vice-versa for the noncrystallizing salts. These observations suggest an explanation, in terms of protein stability and entropy of hydration, of why some salts are good crystallization agents for a given protein and others are not. This in turn provides theoretical insight into the process of protein crystallization, suggesting ways of predicting and controlling it. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 642-652, 2016.

  4. Visualization of Parameter Space for Image Analysis

    Science.gov (United States)

    Pretorius, A. Johannes; Bray, Mark-Anthony P.; Carpenter, Anne E.; Ruddle, Roy A.

    2013-01-01

    Image analysis algorithms are often highly parameterized and much human input is needed to optimize parameter settings. This incurs a time cost of up to several days. We analyze and characterize the conventional parameter optimization process for image analysis and formulate user requirements. With this as input, we propose a change in paradigm by optimizing parameters based on parameter sampling and interactive visual exploration. To save time and reduce memory load, users are only involved in the first step - initialization of sampling - and the last step - visual analysis of output. This helps users to more thoroughly explore the parameter space and produce higher quality results. We describe a custom sampling plug-in we developed for CellProfiler - a popular biomedical image analysis framework. Our main focus is the development of an interactive visualization technique that enables users to analyze the relationships between sampled input parameters and corresponding output. We implemented this in a prototype called Paramorama. It provides users with a visual overview of parameters and their sampled values. User-defined areas of interest are presented in a structured way that includes image-based output and a novel layout algorithm. To find optimal parameter settings, users can tag high- and low-quality results to refine their search. We include two case studies to illustrate the utility of this approach. PMID:22034361

  5. Laser diffraction analysis of colloidal crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sogami, Ikuo S.; Shinohara, Tadatomi; Yoshiyama, Tsuyoshi [Kyoto Sangyo Univ., Department of Physics, Kyoto (Japan)

    2001-10-01

    Laser diffraction analysis is made on crystallization in salt-free aqueous suspensions of highly-charged colloidal particles for semi-dilute specimens of concentration 0.1-10.0 vol%. Kossel diffraction patterns which represent faithfully accurate information on lattice symmetries in the suspensions enable us to investigate the time evolution of colloidal crystals. The results show that the crystallization proceeds by way of the following intermediate phase transitions: two-dimensional hcp structure {yields} random layer structure {yields} layer structure with one sliding degree of freedom {yields} stacking disorder structure {yields} stacking structure with multivariant periodicity {yields} fcc twin structure with twin plane (111) {yields} normal fcc structure {yields} bcc twin structure with twin plane (11-bar2) or (1-bar12) {yields} normal bcc structure. For concentrated suspensions (>2 vol %), the phase transition ceases to proceed at the normal fcc structure. (author)

  6. Calculations of the electronic levels, spin-Hamiltonian parameters and vibrational spectra for the CrCl3 layered crystals

    Science.gov (United States)

    Avram, C. N.; Gruia, A. S.; Brik, M. G.; Barb, A. M.

    2015-12-01

    Calculations of the Cr3+ energy levels, spin-Hamiltonian parameters and vibrational spectra for the layered CrCl3 crystals are reported for the first time. The crystal field parameters and the energy level scheme were calculated in the framework of the Exchange Charge Model of crystal field. The spin-Hamiltonian parameters (zero-field splitting parameter D and g-factors) for Cr3+ ion in CrCl3 crystals were obtained using two independent techniques: i) semi-empirical crystal field theory and ii) density functional theory (DFT)-based model. In the first approach, the spin-Hamiltonian parameters were calculated from the perturbation theory method and the complete diagonalization (of energy matrix) method. The infrared (IR) and Raman frequencies were calculated for both experimental and fully optimized geometry of the crystal structure, using CRYSTAL09 software. The obtained results are discussed and compared with the experimental available data.

  7. Process Parameters of Manufacturing Single Crystal Copper by Heated Mold Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    XU Guangji; DING Zongfu; DING Yutian; KOU Shengzhong; LIU Guanglin; LI Wei

    2005-01-01

    The effect of process parameters on the surface quality of single crystal copper ingot was studied through experiment with a self-designed horizontal heated mould continuous casting apparatus, and the mechanism was analyzed. The results show that the process parameters affect the surface quality of pure copper ingot by affecting the position of the liquid-solid interface in the mould. The position of the liquid-solid interface in the mould must be controlled carefully in an appropriate range determined through experiments in order to gain a single crystal copper ingot with a high surface quality.

  8. Investigation of the Spin Hamiltonian Parameters of Yb3+ in CaWO4 Crystal

    Science.gov (United States)

    Dong, Hui-Ning; Wu, Shao-Yi

    2004-12-01

    In this paper, the spin Hamiltonian parameters g factors g∥ and g⊥ of Yb3+ and hyperfine structure constants A∥ and A⊥ of 171Yb3+ and 173Yb3+ in CaWO4 crystal are calculated from the two-order perturbation formulae. In these formulae, the contributions of the covalence effects, the admixture between J =7/2 and J =5/2 states as well as the second-order perturbation are included. The needed crystal parameters are obtained from the superposition model and the local structure of the studied system. The calculated results are in reasonable agreement with the observed values. The results are discussed.

  9. Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli Bin; Sin, Gürkan; Gernaey, Krist

    2013-01-01

    This paper presents the application of uncertainty and sensitivity analysis as part of a systematic modelbased process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty......, while for sensitivity analysis, global methods including the standardized regression coefficients (SRC) and Morris screening are used to identify the most significant parameters. The potassium dihydrogen phosphate (KDP) crystallization process is used as a case study, both in open-loop and closed...

  10. Study of linear optical parameters of sodium sulphide nano-particles added ADP crystals

    Science.gov (United States)

    Kochuparampil, A. P.; Joshi, J. H.; Dixit, K. P.; Jethva, H. O.; Joshi, M. J.

    2017-05-01

    Ammonium Dihydrogen Phosphate (ADP) is one of the nonlinear optical crystals. It is having various applications like optical mixing, electro-optical modulator, harmonic generators, etc. Chalcogenide compounds are poorly soluble in water and difficult to add in the water soluble ADP crystals. The solubility of Chalcogenide compounds can be increased by synthesizing the nano-structured samples with suitable capping agent. In the present study sodium sulphide was added in to ADP to modify its linear optical parameters. Sodium sulphide nano particles were synthesized by co-precipitation technique using Ethylene diamine as capping agent followed by microwave irradiation. The powder XRD confirmed the nano-structured nature of sodium sulphide nano particles. The solubility of nanoparticles of sodium sulphide increased significantly in water compared to the bulk. Pure and Na2S added ADP crystals were grown by slow solvent evaporation method at room temperature. The presence of sodium in ADP was confirmed by AAS. The UV-Vis spectra were recorded for all crystals. Various optical parameters like, transmittance, energy band gap, extinction coefficient, refractive index, optical conductivity, etc. were evaluated. The electronic polarizibility of pure and doped crystals calculated from energy band gap. The effect of doping concentration was found on various parameters.

  11. Order parameters of liquid crystal on the rubbing surfaces of alignment layers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Liquid crystal (LC) alignment is most important in LC devices. In this paper, we quantitatively analyze the LC scalar order parameters on the rubbed surface of an alignment layer. Careful measurement of dichroic infrared absorbance is performed. The result gives the evidence that the order parameter of LC just on the rubbed alignment film is only 1/3-1/2 that in the LC bulk.

  12. Numerical Research of Materials Crystal Lattice Parameters Based on Rare-Earth Metals

    Directory of Open Access Journals (Sweden)

    Obkhodsky Artem

    2017-01-01

    Full Text Available Geometrical parameters (coordinates and angles of CeO2 crystal lattice by molecular dynamics method are calculated. Calculated parameters of crystal lattice are applied for definition the energy band structure via Hartree-Fock method in an approximation to CO LCAO (crystal orbitals as linear combination of atomic orbitals and using the model of cyclic cluster. Calculated minimum energy band p-d is within the value range of experimental data. Valence band maximum is 4.2 while minimum energy band p-d width is 2.8 eV Quantum-chemical calculations are accelerated by Schwarz inequality and direct inversion method in iterative subspace. The obtained mathematical model is implemented into software package for calculating material properties.

  13. Supersymmetry Parameter Analysis : SPA Convention and Project

    CERN Document Server

    Aguilar-Saavedra, J A; Allanach, Benjamin C; Arnowitt, R; Baer, H A; Bagger, J A; Balázs, C; Barger, V; Barnett, M; Bartl, Alfred; Battaglia, M; Bechtle, P; Belyaev, A; Berger, E L; Blair, G; Boos, E; Bélanger, G; Carena, M S; Choi, S Y; Deppisch, F; Desch, Klaus; Djouadi, A; Dutta, B; Dutta, S; Díaz, M A; Eberl, H; Ellis, Jonathan Richard; Erler, Jens; Fraas, H; Freitas, A; Fritzsche, T; Godbole, Rohini M; Gounaris, George J; Guasch, J; Gunion, J F; Haba, N; Haber, Howard E; Hagiwara, K; Han, L; Han, T; He, H J; Heinemeyer, S; Hesselbach, S; Hidaka, K; Hinchliffe, Ian; Hirsch, M; Hohenwarter-Sodek, K; Hollik, W; Hou, W S; Hurth, Tobias; Jack, I; Jiang, Y; Jones, D R T; Kalinowski, Jan; Kamon, T; Kane, G; Kang, S K; Kernreiter, T; Kilian, W; Kim, C S; King, S F; Kittel, O; Klasen, M; Kneur, J L; Kovarik, K; Kraml, Sabine; Krämer, M; Lafaye, R; Langacker, P; Logan, H E; Ma, W G; Majerotto, Walter; Martyn, H U; Matchev, K; Miller, D J; Mondragon, M; Moortgat-Pick, G; Moretti, S; Mori, T; Moultaka, G; Muanza, S; Mukhopadhyaya, B; Mühlleitner, M M; Nauenberg, U; Nojiri, M M; Nomura, D; Nowak, H; Okada, N; Olive, Keith A; Oller, W; Peskin, M; Plehn, T; Polesello, G; Porod, Werner; Quevedo, Fernando; Rainwater, D L; Reuter, J; Richardson, P; Rolbiecki, K; de Roeck, A; Weber, Ch.

    2006-01-01

    High-precision analyses of supersymmetry parameters aim at reconstructing the fundamental supersymmetric theory and its breaking mechanism. A well defined theoretical framework is needed when higher-order corrections are included. We propose such a scheme, Supersymmetry Parameter Analysis SPA, based on a consistent set of conventions and input parameters. A repository for computer programs is provided which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e+e- linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles. In addition, programs for calculating high-precision low energy observables, the density of cold dark matter (CDM) in the universe as well as the cross sections for CDM search experiments are included. The SPA scheme still requires extended efforts on both the theoretical and experimental side before data can be evaluated in the future at the level of the d...

  14. Scaling of crystal field parameters between Pd 2REIn and Pd 2RESn

    Science.gov (United States)

    Babateen, M.; Neumann, K.-U.; Ziebeck, K. R. A.

    1995-02-01

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd 2REIn and Pd 2RESn (RE = rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation.

  15. An extensive investigation on nucleation, growth parameters, crystalline perfection, spectroscopy, thermal, optical, microhardness, dielectric and SHG studies on potential NLO crystal - Ammonium Hydrogen L-tartarte

    Science.gov (United States)

    Hanumantharao, Redrothu; Kalainathan, S.; Bhagavannarayana, G.; Madhusoodanan, U.

    2013-02-01

    Ammonium Hydrogen L-tartarte (AMT), an organic nonlinear optical crystal was grown by slow evaporation method at ambient temperature. Solubility, metastable zone width and induction period of Ammonium Hydrogen L-tartarte in aqueous solution were determined. Good quality crystals were selected and characterized by Single crystal XRD, HR-XRD, FT-IR, 1H NMR, Mass, TGA-DTA, SEM, EDAX, optical and NLO studies. Single crystal XRD analysis revealed that the crystal system belongs to orthorhombic with cell parameters a = 7.65 Å, b = 7.85 Å and c = 11.07 Å. High-resolution-X-ray diffraction (HR-XRD) analysis was carried out to study the crystalline perfection of the grown crystal. 1H NMR and FTIR spectrum thus confirmed the presence of functional groups of the grown crystal. Molecular mass of AMT was measured accurately by mass spectroscopic analysis. Surface features of the grown crystal were analyzed by SEM, AFM, chemical etching and the presence of elements in the compound was identified by EDAX analysis. Thermal behavior of the grown crystal has been studied by TG/DTA analysis. The recorded UV-Vis-NIR spectrum shows excellent transmission in the region of 190-1100 nm. The Vickers and Knoop's microhardness studies have been carried out on AMT crystals over a range of 10-50 g. Hardness anisotropy has been observed in accordance with the orientation of the crystal. Fluorescence spectral studies were carried in the range of 280-500 nm for the grown crystal. The SHG conversion efficiency and laser damage threshold were measured using an Nd: YAG laser (1064 nm).

  16. Parameters for efficient growth of second harmonic field in nonlinear photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Shereena, E-mail: sherin5462@gmail.com; Khan, Mohd. Shahid; Hafiz, Aurangzeb Khurram

    2014-03-01

    The ultrashort pulse propagation and nonlinear second harmonic generation under the undepleted pump approximation in a quadratic nonlinear photonic crystal (NPC) structure is theoretically investigated and the optimized parameters for high second harmonic generation conversion efficiency are extracted. The transfer matrix method is used for the numerical formulation for oblique angle of incidence. A unique set of material combination GaInP/InAlP is selected as alternating nonlinear and linear layers. The NPC parameters like incident angle and layer thickness are manipulated to obtain the exact phase matching using double resonance condition for a fixed number of layers with known experimental material parameters.

  17. Temperature dependence of ratio between dielectric anisotropy and order parameter in fluorinated nematic liquid crystals

    Institute of Scientific and Technical Information of China (English)

    Ma Heng; Sun Rui-Zhi; Li Zhen-Xin; Liu Yu-Fang

    2008-01-01

    Temperature dependence of ratio between dielectric anisotropy and order parameter of fluorinated nematic liquid crystal is investigated by using a semi-empirical molecular orbital package that can accurately calculate an angle between molecular dipole moment and long axis.We optimize the molecular conformations with three semi-empirical Hamiltonians AM1,PM3 and PM5,and then make a comparison between computational results and experimental measurements.It is shown that the results obtained from AM1 method are in good agreement with the measurements.The present study offers an applicable method to predict the dielectric properties of liquid crystal material.

  18. Fourier Analysis and Structure Determination--Part III: X-ray Crystal Structure Analysis.

    Science.gov (United States)

    Chesick, John P.

    1989-01-01

    Discussed is single crystal X-ray crystal structure analysis. A common link between the NMR imaging and the traditional X-ray crystal structure analysis is reported. Claims that comparisons aid in the understanding of both techniques. (MVL)

  19. Analysis of sagittal spinopelvic parameters in achondroplasia.

    Science.gov (United States)

    Hong, Jae-Young; Suh, Seung-Woo; Modi, Hitesh N; Park, Jong-Woong; Park, Jung-Ho

    2011-08-15

    Prospective radiological analysis of patients with achondroplasia. To analyze sagittal spinal alignment and pelvic orientation in achondroplasia patients. Knowledge of sagittal spinopelvic parameters is important for the treatment of achondroplasia, because they differ from those of the normal population and can induce pain. The study and control groups were composed of 32 achondroplasia patients and 24 healthy volunteers, respectively. All underwent lateral radiography of the whole spine including hip joints. The radiographic parameters examined were sacral slope (SS), pelvic tilt, pelvic incidence (PI), S1 overhang, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis (LL1, LL2), and sagittal balance. Statistical analysis was performed to identify significant differences between the two groups. In addition, correlations between parameters and symptoms were sought. Sagittal spinopelvic parameters, namely, pelvic tilt, pelvic incidence, S1 overhang, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis 1 and sagittal balance were found to be significantly different in the patient and control groups (P achondroplasia patients and normal healthy controls. The present study shows that sagittal spinal and pelvic parameters can assist the treatment of spinal disorders in achondroplasia patients.

  20. Uncertainty Analysis in the Noise Parameters Estimation

    Directory of Open Access Journals (Sweden)

    Pawlik P.

    2012-07-01

    Full Text Available The new approach to the uncertainty estimation in modelling acoustic hazards by means of the interval arithmetic is presented in the paper. In the case of the noise parameters estimation the selection of parameters specifying the acoustic wave propagation in an open space as well as parameters which are required in a form of average values – often constitutes a difficult problem. In such case, it is necessary to determine the variance and then, related strictly to it, the uncertainty of model parameters. The application of the interval arithmetic formalism allows to estimate the input data uncertainties without the necessity of the determination their probability distribution, which is required by other methods of uncertainty assessment. A successive problem in the acoustic hazards estimation is a lack of the exact knowledge of the input parameters. In connection with the above, the analysis of the modelling uncertainty in dependence of inaccuracy of model parameters was performed. To achieve this aim the interval arithmetic formalism – representing the value and its uncertainty in a form of an interval – was applied. The proposed approach was illustrated by the example of the application the Dutch RMR SRM Method, recommended by the European Union Directive 2002/49/WE, in the railway noise modelling.

  1. Optimization of Polishing Parameters with Taguchi Method for LBO Crystal in CMP

    Institute of Scientific and Technical Information of China (English)

    Jun Li; Yongwei Zhu; Dunwen Zuo; Yong Zhu; Chuangtian Chen

    2009-01-01

    Chemical mechanical polishing (CMP) was used to polish Lithium triborate (UB_3O_5 or LBO) crystal. Taguchi method was applied for optimization of the polishing parameters. Material removal rate (MRR) and surface roughness are considered as criteria for the optimization. The polishing pressure, the abrasive concentration and the table velocity are important parameters which influence MRR and surface roughness in CMP of LBO crystal. Experiment results indicate that for MRR the polishing pressure is the most significant polishing parameter followed by table velocity; while for the surface roughness, the abrasive concentration is the most important one. For high MRR in CMP of LBO crystal the optimal conditions are: pressure 620 g/cm~2, concentration 5.0 wt pct, and velocity 60 r/min, respectively. For the best surface roughness the optimal conditions are: pressure 416 g/cm~2, concentration 5.0 wt pct, and velocity 40 r/min, respectively. The contributions of individual parameters for MRR and surface roughness were obtained.

  2. Design Optimization of Structural Parameters for Highly Sensitive Photonic Crystal Label-Free Biosensors

    Directory of Open Access Journals (Sweden)

    Yun-ah Han

    2013-03-01

    Full Text Available The effects of structural design parameters on the performance of nano-replicated photonic crystal (PC label-free biosensors were examined by the analysis of simulated reflection spectra of PC structures. The grating pitch, duty, scaled grating height and scaled TiO2 layer thickness were selected as the design factors to optimize the PC structure. The peak wavelength value (PWV, full width at half maximum of the peak, figure of merit for the bulk and surface sensitivities, and surface/bulk sensitivity ratio were also selected as the responses to optimize the PC label-free biosensor performance. A parametric study showed that the grating pitch was the dominant factor for PWV, and that it had low interaction effects with other scaled design factors. Therefore, we can isolate the effect of grating pitch using scaled design factors. For the design of PC-label free biosensor, one should consider that: (1 the PWV can be measured by the reflection peak measurement instruments, (2 the grating pitch and duty can be manufactured using conventional lithography systems, and (3 the optimum design is less sensitive to the grating height and TiO2 layer thickness variations in the fabrication process. In this paper, we suggested a design guide for highly sensitive PC biosensor in which one select the grating pitch and duty based on the limitations of the lithography and measurement system, and conduct a multi objective optimization of the grating height and TiO2 layer thickness for maximizing performance and minimizing the influence of parameter variation. Through multi-objective optimization of a PC structure with a fixed grating height of 550 nm and a duty of 50%, we obtained a surface FOM of 66.18 RIU−1 and an S/B ratio of 34.8%, with a grating height of 117 nm and TiO2 height of 210 nm.

  3. Supersymmetry Parameter Analysis: SPA Convention and Project

    Energy Technology Data Exchange (ETDEWEB)

    Hinchliffe, I.; et al.

    2005-05-05

    High-precision analyses of supersymmetry parameters aim atreconstructing the fundamental supersymmetric theory and its breakingmechanism. A well defined theoretical framework is needed whenhigher-order corrections are included. We propose such a scheme,Supersymmetry Parameter Analysis SPA, based on a consistent set ofconventions and input parameters. A repository for computer programs isprovided which connect parameters in different schemes and relate theLagrangian parameters to physical observables at LHC and high energy e+e-linear collider experiments, i.e., masses, mixings, decay widths andproduction cross sections for supersymmetric particles. In addition,programs for calculating high-precision low energy observables, thedensity of cold dark matter (CDM) in the universe as well as the crosssections for CDM search experiments are included. The SPA scheme stillrequires extended efforts on both the theoretical and experimental sidebefore data can be evaluated in the future at the level of the desiredprecision. We take here an initial step of testing the SPA scheme byapplying the techniques involved to a specific supersymmetry referencepoint.

  4. Morphology and parameters of crystallization the blend PE/Epoxy/PE-co-PEG; Morfologia e parametros de cristalizacao da blenda PE/epoxi/PE-co-PEG

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Daniela; Coelho, Luiz Antonio Ferreira; Nack, Fernanda; Silva, Bruna Louise, E-mail: dep2db@joinville.udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas

    2014-07-01

    This study aims to evaluate the morphology and crystallization parameters of high density polyethylene (HDPE) with different concentrations of epoxy (DGEBA / OTBG), and the compatibility of this system was used and the copolymer polyethylene-block-poly (ethylene glycol) (PEG-co-PE). The blends were obtained by mechanical mixing on a torque rheometer (Haake). Determined the crystallization parameters of the test matrix differential scanning calorimetry (DSC) and by X-ray diffraction (XRD). The morphology of the system was analyzed by transmission electron microscopy (TEM). It was observed by XRD analysis that the addition of compatibilizer and epoxy resins do not interfere with the crystal structure of HDPE, indicating that the increase in crystallinity associated with the crystallization kinetics. It was observed that the compatibilizing helped the adhesion, reducing the size of the dispersed phase becomes a more stable morphology and obtaining a distribution of the dispersed epoxy phase. (author)

  5. Calculation of crystal-field parameters for rare-earth noble metal alloys

    Energy Technology Data Exchange (ETDEWEB)

    Steinbeck, L. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Richter, M. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Eschrig, H. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Nitzsche, U. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany)

    1995-02-09

    The crystal-field (CF) parameters for 4f electrons of a series of rare-earth impurities in Ag and Au have been evaluated from first-principles density functional calculations of the charge distribution which are based on an optimized LCAO scheme. The localized 4f states are treated as `open core shell`. By including the self-interaction correction for the 4f states, artificial constraints on the 4f charge density employed in earlier density functional CF calculations are avoided. The calculated parameters are compared with recent neutron scattering data. ((orig.)).

  6. Calculation of crystal-field parameters for rare-earth noble metal alloys

    Science.gov (United States)

    Steinbeck, L.; Richter, M.; Eschrig, H.; Nitzsche, U.

    1995-02-01

    The crystal-field (CF) parameters for 4f electrons of a series of rare earth impurities in Ag and Au have been evaluated from first-principles density functional calculations of the charge distribution which are based on an optimized LCAO scheme. The localized 4f states are treated as 'open core shell'. By including the self-interaction correction for the 4f states, artificial constraints on the 4f charge density employed in earlier density functional CF calculations are avoided. The calculated parameters are compared with recent neutron scattering data.

  7. Lattice variation and thermal parameters of gel grown KDP crystals added with some ammonium compounds

    Indian Academy of Sciences (India)

    T H Freeda; C Mahadevan

    2001-10-01

    Pure and impurity added (with NH4Cl, NH4NO3, NH4H2PO4, and (NH4)2SO4) KDP single crystals were grown by the gel method using silica gels. X-ray diffraction data were collected for powder samples and used for the estimation of lattice variation and thermal parameters like Debye–Waller factor, mean-square amplitude of vibration, Debye temperature and Debye frequency. The thermal parameters do not vary in a particular order with respect to impurity concentration. The results obtained are reported and discussed.

  8. Optimization of glass-ceramic crystallization based on DTA exotherm analysis.

    Science.gov (United States)

    Parsell, D E; Anusavice, K J

    1994-05-01

    Crystallization of glass-ceramics is traditionally achieved through a two-stage heat treatment consisting of an isothermal nucleation stage followed by an isothermal growth stage. A method for determining a more efficient heat treatment schedule for a glass-ceramic material using a thermal analysis technique is proposed. The goal of an optimized heat treatment schedule is the production of a glass-ceramic with a desired microstructure (number of crystals per volume) in the shortest amount of time. The proposed method involves differential thermal analysis (DTA) to measure glass crystallization exotherm characteristics which are correlated with the population density of growing crystals, and therefore, to the effectiveness of any prior heat treatment. Traditional thermal processing parameters were investigated and optimized. A method for generating a more efficient heat treatment schedule composed of a series of increasing heating rates was also demonstrated. The thermal analysis method measured a significant effect upon the number density of crystals generated as a function of several experimental variables. Micrographs from samples crystallized with a more time-efficient heat treatment schedule were shown to have equivalent crystal number densities compared to those crystallized with a more time consuming, traditional schedule. This work demonstrated that a rapid thermal analysis method was capable of measuring the relative effectiveness of heat treatment schedules to generate crystalline populations. A novel heat treatment schedule was developed based on progressive adjustment of processing heating rates to generate the maximum crystal population in the shortest amount of time.

  9. A Local Order Parameter-Based Method for Simulation of Free Energy Barriers in Crystal Nucleation.

    Science.gov (United States)

    Eslami, Hossein; Khanjari, Neda; Müller-Plathe, Florian

    2017-03-14

    While global order parameters have been widely used as reaction coordinates in nucleation and crystallization studies, their use in nucleation studies is claimed to have a serious drawback. In this work, a local order parameter is introduced as a local reaction coordinate to drive the simulation from the liquid phase to the solid phase and vice versa. This local order parameter holds information regarding the order in the first- and second-shell neighbors of a particle and has different well-defined values for local crystallites and disordered neighborhoods but is insensitive to the type of the crystal structure. The order parameter is employed in metadynamics simulations to calculate the solid-liquid phase equilibria and free energy barrier to nucleation. Our results for repulsive soft spheres and the Lennard-Jones potential, LJ(12-6), reveal better-resolved solid and liquid basins compared with the case in which a global order parameter is used. It is also shown that the configuration space is sampled more efficiently in the present method, allowing a more accurate calculation of the free energy barrier and the solid-liquid interfacial free energy. Another feature of the present local order parameter-based method is that it is possible to apply the bias potential to regions of interest in the order parameter space, for example, on the largest nucleus in the case of nucleation studies. In the present scheme for metadynamics simulation of the nucleation in supercooled LJ(12-6) particles, unlike the cases in which global order parameters are employed, there is no need to have an estimate of the size of the critical nucleus and to refine the results with the results of umbrella sampling simulations. The barrier heights and the nucleation pathway obtained from this method agree very well with the results of former umbrella sampling simulations.

  10. Effect of process parameters and crystal orientation on 3D anisotropic stress during CZ and FZ growth of silicon

    Science.gov (United States)

    Drikis, Ivars; Plate, Matiss; Sennikovs, Juris; Virbulis, Janis

    2017-09-01

    Simulations of 3D anisotropic stress are carried out in and oriented Si crystals grown by FZ and CZ processes for different diameters, growth rates and process stages. Temperature dependent elastic constants and thermal expansion coefficients are used in the FE simulations. The von Mises stress at the triple point line is 5-11% higher in crystals compared to crystals. The process parameters have a larger effect on the von Mises stress than the crystal orientation. Generally, the crystal has a higher azimuthal variation of stress along the triple point line ( 8%) than the crystal ( 2%). The presence of a crystal ridge increases the stress beside the ridge and decreases it on the ridge compared with the round crystal.

  11. Raman mapping for kinetic analysis of crystallization of amorphous drug based on distributional images.

    Science.gov (United States)

    Ueda, Hiroshi; Ida, Yasuo; Kadota, Kazunori; Tozuka, Yuichi

    2014-02-28

    The feasibility of Raman mapping for understanding the crystallization mechanism of an amorphous drug was investigated using described images. The crystallization tendency of amorphous indomethacin under dry condition at 30 °C was kinetically evaluated by means of Raman mapping and X-ray powder diffraction (XRPD) with change in the calculated crystallinities. Raman images directly revealed the occurrence of particle size-dependent non-uniform crystallization; slow crystallization of large particles, but fast crystallization of small particles. Kinetic analysis by fitting to the Kolmogorov-Johnson-Mehl-Avrami equation was performed for the crystallization profiles of both Raman mapping and XRPD data. For the Raman mapping data, the distribution of large particles was characterized and examined. The kinetic parameters calculated from the whole Raman image area agreed well with those of XRPD, suggesting accurate prediction of both techniques for the entire crystallization. Raman images revealed the change in the crystallization mechanism for the focused area; the large particles showed a reduced crystallization rate constant and an increase in the dimensional crystal growth exponent. Raman mapping is an attractive tool for quantitative and kinetic investigation of the crystallization mechanism with distributional images.

  12. Parameter Uncertainty for Repository Thermal Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Greenberg, Harris [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dupont, Mark [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-01

    This report is one follow-on to a study of reference geologic disposal design concepts (Hardin et al. 2011a). Based on an analysis of maximum temperatures, that study concluded that certain disposal concepts would require extended decay storage prior to emplacement, or the use of small waste packages, or both. The study used nominal values for thermal properties of host geologic media and engineered materials, demonstrating the need for uncertainty analysis to support the conclusions. This report is a first step that identifies the input parameters of the maximum temperature calculation, surveys published data on measured values, uses an analytical approach to determine which parameters are most important, and performs an example sensitivity analysis. Using results from this first step, temperature calculations planned for FY12 can focus on only the important parameters, and can use the uncertainty ranges reported here. The survey of published information on thermal properties of geologic media and engineered materials, is intended to be sufficient for use in generic calculations to evaluate the feasibility of reference disposal concepts. A full compendium of literature data is beyond the scope of this report. The term “uncertainty” is used here to represent both measurement uncertainty and spatial variability, or variability across host geologic units. For the most important parameters (e.g., buffer thermal conductivity) the extent of literature data surveyed samples these different forms of uncertainty and variability. Finally, this report is intended to be one chapter or section of a larger FY12 deliverable summarizing all the work on design concepts and thermal load management for geologic disposal (M3FT-12SN0804032, due 15Aug2012).

  13. THEORETICAL ANALYSIS OF KINETICS OF NONISOTHERMAL CRYSTALLIZATION OF POLYMERS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhiying

    1994-01-01

    The classical crystallization theories proposed by Avrami, Evans, and Mandelkern were extended to the nonisothermal situation. The expressions derived from the classical equations can be expressed in either the differential form or the integral form. A method was provided so as to obtain the parameters characterizing the crystallization rate and mechanism from DSC curves with several constant heating or cooling rates. The rate constants of crystallization obtained from both isothermal and nonisothermal curves of poly(ethylene terephthalate)were compared.

  14. Determination and analysis of synchronous motor's parameters

    Science.gov (United States)

    Mesņajevs, Aleksandrs; Zviedris, Andrejs

    2009-01-01

    In this work the parameters of synchronous machines are analyzed- direct-axis reaction Xad and quadrature-axis reaction Xaq. Methods of calculation in view of magnetic system's and its element's saturation are presented. It is shown that definition of these reactances, using as a basis a two-reaction method, is not correct and connected with work demanding chart analyzing calculations. The new approach to the qualitative and quantitative analysis of synchronous machine's operating modes which is based on consecutive use of the magnetic field's theory is offered, without it with two-reaction parameters Xad and Xaq. This approach is realized by means of a magnetic field's modeling using numerical methods with help of modern computers.

  15. Orientational order parameter studies in two symmetric dimeric liquid crystals - an optical study

    Science.gov (United States)

    Pardhasaradhi, P.; Datta Prasad, P. V.; Madhavi Latha, D.; Pisipati, V. G. K. M.; Padmaja Rani, G.

    2012-12-01

    The optical technique developed by [W. Kuczynski, B. Zywucki, and J. Malecki, Determination of orientational order parameter in various liquid-crystalline phases, Mol. Cryst. Liq. Cryst. 381 (2002), pp. 1-19; B.J. Zywucki and W. Kuczynski, IEEE transactions on optical phenomena - The orientational order in nematic liquid crystals from birefringence measurements, Dielectr. Electr. Insul. 8 (2001), pp. 512-515] is fabricated and used to determine the orientational order parameter in two dimeric liquid crystalline compounds nematic and SmA phases of α,ω-bis(4-alkylanilinebenzylidene-4‧-oxy)alkane (m.OnO.m) homologous series. The compounds studied are 5.O8O.5 and 5.O10O.5 which exhibit nematic and SmA, and nematic phases, respectively. The orientational order parameter in both the phases of nematic and SmA phases of the compound one and the nematic phase of the compound two are obtained using the principle of Newton's rings which gives directly the birefringence, δn of the liquid crystal dimer. The merits of the technique used are presented over the conventional techniques for the determination of orientational order parameter. The results for the two compounds are compared with those values estimated from n e, n o and density using the two internal field models due to Vuks and Neugebauer applicable to nematic phase.

  16. Crystallization And Preliminary Crystallographic Analysis of Recombinant Human Galectin-1

    Energy Technology Data Exchange (ETDEWEB)

    Scott, S.A.; Scott, K.; Blanchard, H.

    2009-06-04

    Human galectin-1 has been cloned, expressed in E. coli, purified and crystallized in the presence of both lactose (ligand) and {beta}-mercaptoethanol under six different conditions. The X-ray diffraction data obtained have enabled the assignment of unit-cell parameters for two novel crystal forms of human galectin-1.

  17. Economic analysis of crystal growth in space

    Science.gov (United States)

    Ulrich, D. R.; Chung, A. M.; Yan, C. S.; Mccreight, L. R.

    1972-01-01

    Many advanced electronic technologies and devices for the 1980's are based on sophisticated compound single crystals, i.e. ceramic oxides and compound semiconductors. Space processing of these electronic crystals with maximum perfection, purity, and size is suggested. No ecomonic or technical justification was found for the growth of silicon single crystals for solid state electronic devices in space.

  18. Crystal lattice properties fully determine short-range interaction parameters for alkali and halide ions

    CERN Document Server

    Mao, Albert H; 10.1063/1.4742068

    2012-01-01

    Accurate models of alkali and halide ions in aqueous solution are necessary for computer simulations of a broad variety of systems. Previous efforts to develop ion force fields have generally focused on reproducing experimental measurements of aqueous solution properties such as hydration free energies and ion-water distribution functions. This dependency limits transferability of the resulting parameters because of the variety and known limitations of water models. We present a solvent-independent approach to calibrating ion parameters based exclusively on crystal lattice properties. Our procedure relies on minimization of lattice sums to calculate lattice energies and interionic distances instead of equilibrium ensemble simulations of dense fluids. The gain in computational efficiency enables simultaneous optimization of all parameters for Li+, Na+, K+, Rb+, Cs+, F-, Cl-, Br-, and I- subject to constraints that enforce consistency with periodic table trends. We demonstrate the method by presenting lattice-d...

  19. Estimation of Hoffman-Lauritzen parameters from nonisothermal crystallization kinetics of PET/MWCNT nanocomposites

    Science.gov (United States)

    Gaonkar, Amita; Murudkar, Vrishali; Deshpande, V. D.

    2016-05-01

    Polyethylene terephthalate (PET) and Nucleated PET/ multi-walled carbon nanotubes (MWCNTs) nanocomposites with different MWCNTs loadings were prepared by melt compounding. The influence of the addition of MWCNTs and precipitated PET (p-PET) on the morphology and thermal properties of the nanocomposites was investigated. From Transmission Electronic Microscopy (TEM) and Wide angle X-Ray diffraction (WAXD) study, it can be clearly seen that nanocomposites with low MWCNTs contents (0.1 wt. %) get better MWCNTs dispersion than higher MWCNT loading. Comparing with PET, nucleated PET nanocomposite with 0.1% MWCNT loading shows higher value of Lauritzen-Hoffman parameters U* and Kg evaluated using the differential isoconversional method. Crystallization regime transition temperature range shifts to higher temperature (208°C - 215°C) for nanocomposites. The presence of p-PET in addition of MWCNT, which act as good nucleating agent, enhanced the crystallization of PET through heterogeneous nucleation.

  20. Strain gradient crystal plasticity analysis of a single crystal containing a cylindrical void

    DEFF Research Database (Denmark)

    Borg, Ulrik; Kysar, J.W.

    2007-01-01

    The effects of void size and hardening in a hexagonal close-packed single crystal containing a cylindrical void loaded by a far-field equibiaxial tensile stress under plane strain conditions are studied. The crystal has three in-plane slip systems oriented at the angle 60 degrees with respect...... to one another. Finite element simulations are performed using a strain gradient crystal plasticity formulation with an intrinsic length scale parameter in a non-local strain gradient constitutive framework. For a vanishing length scale parameter the non-local formulation reduces to a local crystal...... to three times higher for smaller void sizes than for larger void sizes in the non-local material....

  1. Crystal nucleation in binary hard-sphere mixtures: the effect of order parameter on the cluster composition

    NARCIS (Netherlands)

    Ni, R.; Smallenburg, F.; Filion, L.C.; Dijkstra, M.

    2011-01-01

    We study crystal nucleation in a binary mixture of hard spheres and investigate the composition and size of the (non)critical clusters using Monte Carlo simulations. In order to study nucleation of a crystal phase in computer simulations, a one-dimensional order parameter is usually defined to ident

  2. Investigations of EPR parameters for the trigonal Ti3+-Ti3+ pair in beryl crystal.

    Science.gov (United States)

    Wang, Fang; Zheng, Wen-Chen

    2007-08-01

    By using the complete diagonalization of energy matrix of 3d1 ions in trigonal symmetry, the EPR parameters (g factors g( parallel), g( perpendicular) and zero-field splitting D) of the trigonal Ti3+-Ti3+ pair in beryl crystal are calculated. In the calculations, the exchange interaction in the Ti3+-Ti3+ pair is taken as the perturbation and the local trigonal distortion in the defect center is considered. The results (which are in agreement with the experimental values) are discussed.

  3. Identification of the crystallization kinetic parameters of a semi-crystalline polymer by using PVTα measurement

    Science.gov (United States)

    Tardif, X.; Sobotka, V.; Boyard, N.; Delaunay, D.

    2011-05-01

    Injection molding is the most widely used process in the plastic industry. In the case of semi-crystalline polymer, crystallization kinetics impacts directly the quality of the piece, both on dimensional and mechanical aspects. The characterization of these kinetics is therefore of primary importance to model the process, in particular during the cooling phase. To be representative, this characterization must be carried out under conditions as close as possible to those encountered in the process: high pressure, high cooling rate, shearing, and potential presence of fibers. However, conventional apparatus such as the differential scanning calorimeter do not allow to reach these conditions. A PVTα apparatus, initially developed in the laboratory for the characterization of thermoset composites, was adapted to identify the crystallization kinetics. The aim of the presented study is to demonstrate the feasibility of the identification. This device allows the molding of a circular sample of 40 mm diameter and 6 mm thick by controlling the applied pressure on the sample and the temperature field on its surfaces. This mold is designed such as heat transfer is 1D within the thickness of the sample. It is equipped with two heat flux sensors to determine the average crystallization rate through the thickness and a displacement sensor for the determination of the volume change. The heat transfer problem between the polymer and the molding cavity is modeled by using a 1D conduction problem with a moving boundary, in which the control volume is a uniform temperature disk with a variable volume, and coupled to a crystallization kinetic model. An inverse method is used to identify the parameters of the crystallization kinetic model by minimizing an objective function based on the difference between the evolutions of the experimental and computed volume of the sample. The first validation of this methodology was to compare the kinetic parameters identified with this apparatus

  4. Optical Dispersion Parameters with Different Orientations for SrLaAlO4 Single Crystals

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The different optical dispersion parameters of SrLaAlO4 single crystals have been studied by the transmission andreflection measurements at normal incidence for the three orientations 001, 100 and 101 in the spectral range400 nm~2500 nm.The optical absorption data revealed the existance of allowed indirect and direct transition. Therefractive index has abnormal behaviour in the spectral region 400~900 nm, but has a normal one in the higherwavelength region. The optical dispersion parameters, the single oscillator energy Eo and the dispersion energy Edwere determined and indicated the ionic structure of the material. The high-frequency dielectric constant, the latticedielectric constant and the electronic polarizability were determined by the free carriers and the lattice vibrationmodes. The real dielectric constant e1, the dielectric loss tangent (tanδ), the volume (VELF) and the surface energyloss function (SELF) have also been discussed.

  5. Calculated crystal-field parameters for rare-earth impurities in noble metals

    Science.gov (United States)

    Steinbeck, Lutz; Richter, Manuel; Eschrig, Helmut; Nitzsche, Ulrike

    1994-06-01

    From first-principles density-functional calculations of the charge distribution the crystal-field (CF) parameters for 4f states of Er and Dy impurities in Ag and Au have been evaluated. The calculations are based on an optimized linear combination of atomic orbitals scheme, where the local-density approximation (LDA) is used for the conduction-electron states, while the localized rare-earth 4f states are treated as ``open core shell.'' As the 4f localization cannot be properly described within LDA, a self-interaction correction for the 4f states is included. In this way, any artificial constraints on the 4f charge density employed in earlier first-principles CF calculations are avoided. The calculated CF parameters agree well with recent neutron scattering data.

  6. Optical properties of 3d-ions in crystals spectroscopy and crystal field analysis

    CERN Document Server

    Brik, Mikhail

    2013-01-01

    "Optical Properties of 3d-Ions in Crystals: Spectroscopy and Crystal Field Analysis" discusses spectral, vibronic and magnetic properties of 3d-ions in a wide range of crystals, used as active media for solid state lasers and potential candidates for this role. Crystal field calculations (including first-principles calculations of energy levels and absorption spectra) and their comparison with experimental spectra, the Jahn-Teller effect, analysis of vibronic spectra, materials science applications are systematically presented. The book is intended for researchers and graduate students in crystal spectroscopy, materials science and optical applications. Dr. N.M. Avram is an Emeritus Professor at the Physics Department, West University of Timisoara, Romania; Dr. M.G. Brik is a Professor at the Institute of Physics, University of Tartu, Estonia.

  7. Order-parameter-aided temperature-accelerated sampling for the exploration of crystal polymorphism and solid-liquid phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tang-Qing, E-mail: tangqing.yu@nyu.edu; Vanden-Eijnden, Eric, E-mail: eve2@cims.nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Chen, Pei-Yang; Chen, Ming [Department of Chemistry, New York University, New York, New York 10003 (United States); Samanta, Amit [Program in Applied and Computational Mathematics, Princeton University, Princeton, New Jersey 08544, USA and Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Tuckerman, Mark, E-mail: mark.tuckerman@nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Department of Chemistry, New York University, New York, New York 10003 (United States); NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062 (China)

    2014-06-07

    The problem of predicting polymorphism in atomic and molecular crystals constitutes a significant challenge both experimentally and theoretically. From the theoretical viewpoint, polymorphism prediction falls into the general class of problems characterized by an underlying rough energy landscape, and consequently, free energy based enhanced sampling approaches can be brought to bear on the problem. In this paper, we build on a scheme previously introduced by two of the authors in which the lengths and angles of the supercell are targeted for enhanced sampling via temperature accelerated adiabatic free energy dynamics [T. Q. Yu and M. E. Tuckerman, Phys. Rev. Lett. 107, 015701 (2011)]. Here, that framework is expanded to include general order parameters that distinguish different crystalline arrangements as target collective variables for enhanced sampling. The resulting free energy surface, being of quite high dimension, is nontrivial to reconstruct, and we discuss one particular strategy for performing the free energy analysis. The method is applied to the study of polymorphism in xenon crystals at high pressure and temperature using the Steinhardt order parameters without and with the supercell included in the set of collective variables. The expected fcc and bcc structures are obtained, and when the supercell parameters are included as collective variables, we also find several new structures, including fcc states with hcp stacking faults. We also apply the new method to the solid-liquid phase transition in copper at 1300 K using the same Steinhardt order parameters. Our method is able to melt and refreeze the system repeatedly, and the free energy profile can be obtained with high efficiency.

  8. Vacuum pyrolysis characteristics and kinetic analysis of liquid crystal from scrap liquid crystal display panels.

    Science.gov (United States)

    Chen, Ya; Zhang, Lingen; Xu, Zhenming

    2017-04-05

    Recycling of waste liquid crystal display (LCD) panels is an urgent task with the rapid expanding LCD market. However, as important composition of LCD panels, the treatment of liquid crystal is seldom concerned for its low concentration. In present study, a stripping product enriched liquid crystal and indium is gained by mechanical stripping process, in which liquid crystal is enriched from 0.3wt.% to 53wt.% and indium is enriched from 0.02wt.% to 7.95wt.%. For the stripping product, liquid crystal should be removed before indium recovery because (a) liquid crystal will hinder indium recycling; (b) liquid crystal is hazardous waste. Hence, an effective and green approach by vacuum pyrolysis is proposed to treat liquid crystal in the stripping product. The results are summarized as: (i) From the perspective of apparent activation energy, the advantages of vacuum pyrolysis is expounded according to kinetic analysis. (ii) 89.10wt.% of liquid crystal is converted and the content of indium in residue reaches 14.18wt.% under 773K, 15min and system pressure of 20Pa. This study provides reliable information for further industrial application and an essential pretreatment for the next step of indium recycling.

  9. Thermodynamic scaling of dynamic properties of liquid crystals: verifying the scaling parameters using a molecular model.

    Science.gov (United States)

    Satoh, Katsuhiko

    2013-08-28

    The thermodynamic scaling of molecular dynamic properties of rotation and thermodynamic parameters in a nematic phase was investigated by a molecular dynamic simulation using the Gay-Berne potential. A master curve for the relaxation time of flip-flop motion was obtained using thermodynamic scaling, and the dynamic property could be solely expressed as a function of TV(γτ) , where T and V are the temperature and volume, respectively. The scaling parameter γτ was in excellent agreement with the thermodynamic parameter Γ, which is the logarithm of the slope of a line plotted for the temperature and volume at constant P2. This line was fairly linear, and as good as the line for p-azoxyanisole or using the highly ordered small cluster model. The equivalence relation between Γ and γ(τ) was compared with results obtained from the highly ordered small cluster model. The possibility of adapting the molecular model for the thermodynamic scaling of other dynamic rotational properties was also explored. The rotational diffusion constant and rotational viscosity coefficients, which were calculated using established theoretical and experimental expressions, were rescaled onto master curves with the same scaling parameters. The simulation illustrates the universal nature of the equivalence relation for liquid crystals.

  10. The construction of the CMS electromagnetic calorimeter: automatic measurements of the physics parameters of PWO crystals

    CERN Multimedia

    2005-01-01

    Crystal properties (dimensions, optical transmission, light yield) are automatically measured. The pictures show different measurement stations of the automatic machine. Crystals are measured on trays containing five crystals each.

  11. CRYSTALLIZATION KINETICS OF GLASS-CERAMICS BY DIFFERENTIAL THERMAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    A. NOZAD

    2011-06-01

    Full Text Available The crystallization behavior of fluorphlogopite, a glass-ceramic in the MgO–SiO2–Al2O3–K2O–B2O3–F system, was studied by substitution of Li2O for K2O in the glass composition. DTA, XRD and SEM were used for the study of crystallization behavior, formed phases and microstructure of the resulting glass-ceramics. Crystallization kinetics of the glass was investigated under non-isothermal conditions, using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed, and both the activation energy of crystallization process as well as the crystallization mechanism were characterized. Calculated kinetic parameters indicated that the appropriate crystallization mechanism was bulk crystallization for base glass and the sample with addition of Li2O. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses was in the range of 234-246 KJ/mol and in the samples with addition of Li2O was changed to the range of 317-322 KJ/mol.

  12. Influence of composition on microstructural parameters of single crystal nickel-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    MacKay, R.A., E-mail: Rebecca.A.MacKay@nasa.gov [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Gabb, T.P. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Garg, A. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); University of Toledo, 2801 W. Bancroft, Toledo, Ohio 43606 (United States); Rogers, R.B.; Nathal, M.V. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States)

    2012-08-15

    Fourteen nickel-base superalloy single crystals containing a range of chromium (Cr), cobalt (Co), molybdenum (Mo), and rhenium (Re) levels, and fixed amounts of aluminum (Al) and tantalum (Ta), were examined to determine the effect of bulk composition on basic microstructural parameters, including {gamma} Prime solvus, {gamma} Prime volume fraction, topologically close-packed (TCP) phases, {gamma} and {gamma} Prime phase chemistries, and {gamma}-{gamma} Prime lattice mismatch. Regression models describing the influence of bulk alloy composition on each of the microstructural parameters were developed and compared to predictions by a commercially-available software tool that used computational thermodynamics. Co produced the largest change in {gamma} Prime solvus over the wide compositional range explored and Mo produced the biggest effect on the {gamma} lattice parameter over its range, although Re had a very potent influence on all microstructural parameters investigated. Changing the Cr, Co, Mo, and Re contents in the bulk alloy had an impact on their concentrations in the {gamma} matrix and to a smaller extent in the {gamma} Prime phase. The software tool under-predicted {gamma} Prime solvus temperatures and {gamma} Prime volume fractions, and over-predicted TCP phase volume fractions at 982 Degree-Sign C. However, the statistical regression models provided excellent estimations of the microstructural parameters and demonstrated the usefulness of such formulas. - Highlights: Black-Right-Pointing-Pointer Effects of Cr, Co, Mo, and Re on microstructure in new low density superalloys Black-Right-Pointing-Pointer Co produced a large change in {gamma} Prime solvus; Mo had a large effect on lattice mismatch. Black-Right-Pointing-Pointer Re exhibited very potent influence on all microstructural parameters was investigated. Black-Right-Pointing-Pointer {gamma} and {gamma} Prime phase chemistries both varied with temperature and alloy composition. Black

  13. Crystal field parameters and crystal field linewidths in the (REY)Pd/sub 3/ and (REY)Al/sub 2/ alloys

    Energy Technology Data Exchange (ETDEWEB)

    Walter, U.; Holland-Moritz, E.

    1981-12-01

    The LLW-parameters x and W of dilute rare earth impurities (RE = Pr, Nd, Tb, Dy, Ho, Er, Tm; c approx. equal to 0.05) in the cubic matrices YPd/sub 3/ and YAl/sub 2/ could be determined unequivocally in the crystal field scheme of Lea, Leask and Wolf by inelastic neutron scattering. The crystal field parameters derived from x and W are not consistent with the point charge model. The ratio of N(Esub(F))Jsub(ex) for the (REY)Al/sub 2/ extracted from the RE-linewidths correlates with the corresponding ratio extracted from their magnetic ordering temperatures.

  14. Unscented Kalman filter with parameter identifiability analysis for the estimation of multiple parameters in kinetic models

    OpenAIRE

    Baker Syed; Poskar C; Junker Björn

    2011-01-01

    Abstract In systems biology, experimentally measured parameters are not always available, necessitating the use of computationally based parameter estimation. In order to rely on estimated parameters, it is critical to first determine which parameters can be estimated for a given model and measurement set. This is done with parameter identifiability analysis. A kinetic model of the sucrose accumulation in the sugar cane culm tissue developed by Rohwer et al. was taken as a test case model. Wh...

  15. Crystal quality analysis and improvement using x-ray topography

    Science.gov (United States)

    Maj, J. A.; Goetze, K.; Macrander, A. T.; Zhong, Y. C.; Huang, X. R.; Maj, L.

    2008-08-01

    The Topography X-ray Laboratory of the Advanced Photon Source (APS) at Argonne National Laboratory operates as a collaborative effort with APS users to produce high performance crystals for APS X-ray beamline experiments. For many years the topography laboratory has worked closely with an on-site optics shop to help ensure the production of crystals with the highest quality, most stress-free surface finish possible. It has been instrumental in evaluating and refining methods used to produce high quality crystals. Topographical analysis has shown to be an effective method to quantify and determine the distribution of stresses, to help identify methods that would mitigate the stresses and improve the Rocking curve, and to create CCD images of the crystal. This paper describes the topography process and offers methods for reducing crystal stresses in order to substantially improve the crystal optics.

  16. Crystal quality analysis and improvement using x-ray topography.

    Energy Technology Data Exchange (ETDEWEB)

    Maj, J.; Goetze, K.; Macrander, A.; Zhong, Y.; Huang, X.; Maj, L.; Univ. of Chicago

    2008-01-01

    The Topography X-ray Laboratory of the Advanced Photon Source (APS) at Argonne National Laboratory operates as a collaborative effort with APS users to produce high performance crystals for APS X-ray beamline experiments. For many years the topography laboratory has worked closely with an on-site optics shop to help ensure the production of crystals with the highest quality, most stress-free surface finish possible. It has been instrumental in evaluating and refining methods used to produce high quality crystals. Topographical analysis has shown to be an effective method to quantify and determine the distribution of stresses, to help identify methods that would mitigate the stresses and improve the Rocking curve, and to create CCD images of the crystal. This paper describes the topography process and offers methods for reducing crystal stresses in order to substantially improve the crystal optics.

  17. Quartz Crystal Microbalance Technique for in Situ Analysis of Supersaturation in Cooling Crystallization.

    Science.gov (United States)

    Liu, Li-Shang; Kim, Jong-Min; Kim, Woo-Sik

    2016-06-07

    A quartz crystal microbalance (QCM) is used as a novel in situ strategy for analyzing the supersaturation profile during cooling crystallization. The main concept is based on preventing any solid mass loading on the QCM sensor by modifying the sensor surface. As a result, the QCM responses only depend on the solution concentration changes during the crystallization. The proposed strategy is confirmed on the basis of an analysis of sulfamerazine (SMZ) crystallization. When the QCM sensor is modified using 11-amino-1-undecanethiol (AUT), crystal formation on the sensor is completely prevented due to a repulsive interaction between the -NH2 functional groups of the AUT and SMZ crystals. Thus, the QCM responses reflect only the property changes in the solution phase during the crystallization. The supersaturation in the solution is then estimated on the basis of the difference in the frequency shifts between the SMZ solution and a blank solution. The accuracy of the in situ QCM analysis of supersaturation is confirmed using an off-line gravimetric method.

  18. Novel cell parameter determination of a twisted-nematic liquid crystal display

    Institute of Scientific and Technical Information of China (English)

    Huang Xia; Jing Hai; Fu Guo-Zhu

    2008-01-01

    In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays (TNLCD) by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate.

  19. Effects of Microstructural Parameters on Creep of Nickel-Base Superalloy Single Crystals

    Science.gov (United States)

    MacKay, Rebecca A.; Gabb, Timothy P.; Nathal, Michael V.

    2013-01-01

    Microstructure-sensitive creep models have been developed for Ni-base superalloy single crystals. Creep rupture testing was conducted on fourteen single crystal alloys at two applied stress levels at each of two temperatures, 982 and 1093 C. The variation in creep lives among the different alloys could be explained with regression models containing relatively few microstructural parameters. At 982 C, gamma-gamma prime lattice mismatch, gamma prime volume fraction, and initial gamma prime size were statistically significant in explaining the creep rupture lives. At 1093 C, only lattice mismatch and gamma prime volume fraction were significant. These models could explain from 84 to 94 percent of the variation in creep lives, depending on test condition. Longer creep lives were associated with alloys having more negative lattice mismatch, lower gamma prime volume fractions, and finer gamma prime sizes. The gamma-gamma prime lattice mismatch exhibited the strongest influence of all the microstructural parameters at both temperatures. Although a majority of the alloys in this study were stable with respect to topologically close packed (TCP) phases, it appeared that up to approximately 2 vol% TCP phase did not affect the 1093 C creep lives under applied stresses that produced lives of approximately 200 to 300 h. In contrast, TCP phase contents of approximately 2 vol% were detrimental at lower applied stresses where creep lives were longer. A regression model was also developed for the as-heat treated initial gamma prime size; this model showed that gamma prime solvus temperature, gamma-gamma prime lattice mismatch, and bulk Re content were all statistically significant.

  20. Degradation of crystal violet over heterogeneous TiO2 -based catalysts: The effect of process parameters

    Directory of Open Access Journals (Sweden)

    Marija B. Vasić

    2016-09-01

    Full Text Available In this study, modified sol-gel method was employed to synthesize the pure and Zr-doped titania catalysts. Brunauer-Emmett-Teller (BET method was applied to determine porosity, X-ray diffraction (XRD analysis was used to study crystal structure, scanning electron microscopy (SEM was used to investigate morphology and Fourier transform infrared spectroscopy (FTIR was used to examine surface properties/total acidity of the obtained catalysts samples. Photocatalytic activity was tested in the reaction of crystal violet (CV dye decolourization/degradation under UV light irradiation. The effects of several photocatalysis operational parameters were considered, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment, as well as catalysts calcination temperatures and dopant amounts. The obtained results indicated faster dye decolourization/degradation with the increase of the catalyst dosage and the decrease of initial CV concentrations. The Zr-doping affects photocatalytic properties, i.e. CV decolourization/degradation of the prepared catalytic materials. Thus, addition of 5 wt.% of ZrO2 to titania increases photocatalytic effect for ∼15% and addition of 10 wt.% of ZrO2 improves the photocatalytic efficiency of titania for nearly 30%.

  1. Structure analysis on synthetic emerald crystals

    Science.gov (United States)

    Lee, Pei-Lun; Lee, Jiann-Shing; Huang, Eugene; Liao, Ju-Hsiou

    2013-05-01

    Single crystals of emerald synthesized by means of the flux method were adopted for crystallographic analyses. Emerald crystals with a wide range of Cr3+-doping content up to 3.16 wt% Cr2O3 were examined by X-ray single crystal diffraction refinement method. The crystal structures of the emerald crystals were refined to R 1 (all data) of 0.019-0.024 and w R 2 (all data) of 0.061-0.073. When Cr3+ substitutes for Al3+, the main adjustment takes place in the Al-octahedron and Be-tetrahedron. The effect of substitution of Cr3+ for Al3+ in the beryl structure results in progressively lengthening of the Al-O distance, while the length of the other bonds remains nearly unchanged. The substitution of Cr3+ for Al3+ may have caused the expansion of a axis, while keeping the c axis unchanged in the emerald lattice. As a consequence, the Al-O-Si and Al-O-Be bonding angles are found to decrease, while the angle of Si-O-Be increases as the Al-O distance increases during the Cr replacement.

  2. Algorithm and program for precise determination of unit-cell parameters of single crystal taking into account the sample eccentricity

    Science.gov (United States)

    Dudka, A. P.; Smirnova, E. S.; Verin, I. A.; Bolotina, N. B.

    2017-07-01

    A technique has been developed to refine the unit-cell parameters of single crystals with minimization of the influence of instrumental errors on the result. The corresponding computational procedure HuberUB is added to the software package of Huber-5042 diffractometer with a point detector and closedcycle helium cryostat Displex DE-202. The parameters of unit cell, its orientation, the goniometer zero angles, the sample eccentricity, the distances in the goniometer, and the radiation wavelength were refined by the nonlinear least-squares method, which allows imposition of constraints on the unit-cell parameters, depending on the crystal symmetry. The technique is approved on a LuB12 single crystal. The unit-cell parameters are determined in a temperature range of 20-295 K, with an absolute error not larger than 0.0004 Å (the relative error is of 5 × 10-5). The estimates of the unit-cell parameters obtained by the proposed method are evidenced to be unbiased. Some specific features of the behavior of parameters in the ranges of 120-140 and 20-50 K are revealed, which correlate with the anomalies of the physical properties of the crystal.

  3. Studies on the effect of different operational parameters on the crystallization kinetics of α-lactose monohydrate single crystals in aqueous solution

    Science.gov (United States)

    Parimaladevi, P.; Srinivasan, K.

    2014-09-01

    Supersaturation dependent nucleation, size and morphology of alpha-lactose monohydrate (α-LM) crystals from aqueous solution were investigated by adopting two different crystallization methods, slow evaporation and fast evaporation, in the supersaturation range between σ=0.05 and 1.30. The induction period of nucleation is comparatively long in case of slow evaporation and is very short in case of fast evaporation process as the interconversion between α-L and β-L is uncontrollable in the former and is under control in the latter case. Moreover α-LM crystals with tomahawk morphology were obtained throughout the supersaturation range by slow evaporation method whereas crystals with tomahawk, triangular and needle-like morphologies were obtained in supersaturation ranges σ=0.05-0.5, σ=0.5-0.9 and σ=0.9-1.30 respectively by fast evaporation method. Experimentally observed nucleation parameters were verified with theoretically deuced values. It is realized that the fast evaporation method employed in the present study is found to be highly efficient in controlling the interconversion between α-L and β-L as well as in suppressing the inhibitory activity of β molecule on the nucleation and growth of α-LM crystals when compared to conventional slow evaporation method and is successful in producing the industrially preferred needle-like crystals at high supersaturation ranges.

  4. Fabrication and Analysis of Photonic Crystals

    Science.gov (United States)

    Campbell, Dean J.; Korte, Kylee E.; Xia, Younan

    2007-01-01

    These laboratory experiments are designed to explore aspects of nanoscale chemistry by constructing and spectroscopically analyzing thin films of photonic crystals. Films comprised of colloidal spheres and polydimethylsiloxane exhibit diffraction-based stop bands that shift reversibly upon exposure to some common solvents. Topics covered in these…

  5. Design and optimization of production parameters for boric acid crystals with the crystallization process in an MSMPR crystallizer using FBRM® and PVM® technologies

    Science.gov (United States)

    Kutluay, Sinan; Şahin, Ömer; Ceyhan, A. Abdullah; İzgi, M. Sait

    2017-06-01

    In crystallization studies, newly developed technologies, such as Focused Beam Reflectance Measurement (FBRM) and Particle Vision and Measurement (PVM) are applied for determining on-line monitoring of a representation of the Chord Length Distribution (CLD) and observe the photographs of crystals respectively; moreover recently they are widely used. Properly installed, the FBRM ensures on-line determination of the CLD, which is statistically associated to the Crystal Size Distribution (CSD). In industrial crystallization, CSD and mean crystal size as well as external habit and internal structure are important characteristics for further use of the crystals. In this paper, the effect of residence time, stirring speed, feeding rate, supersaturation level and the polyelectrolytes such as anionic polyacrylamide (APAM) and non-ionic polyacrylamide (NPAM) on the CLD as well as the shape of boric acid crystals were investigated by using the FBRM G600 and the PVM V819 probes respectively in an MSMPR (Mixed Suspension Mixed Product Removal) crystallizer. The CSD and kinetic data were determined experimentally using continuous MSMPR crystallizer running at steady state. The population density of nuclei, the nucleation rate and the growth rate were determined from the experimental population balance distribution when the steady state was reached.

  6. Analysis of Modeling Parameters on Threaded Screws.

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, Miquela S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brake, Matthew Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vangoethem, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry cause issues when generating a mesh of the model. This paper will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. The results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.

  7. Optical characterization of the nematic lyotropic chromonic liquid crystals: light absorption, birefringence, and scalar order parameter.

    Science.gov (United States)

    Nastishin, Yu A; Liu, H; Schneider, T; Nazarenko, V; Vasyuta, R; Shiyanovskii, S V; Lavrentovich, O D

    2005-10-01

    We report on the optical properties of the nematic (N) phase formed by lyotropic chromonic liquid crystals (LCLCs) in well aligned planar samples. LCLCs belong to a broad class of materials formed by one-dimensional molecular self-assembly and are similar to other systems such as "living polymers" and "wormlike micelles." We study three water soluble LCLC forming materials: disodium chromoglycate, a derivative of indanthrone called Blue 27, and a derivative of perylene called Violet 20. The individual molecules have a planklike shape and assemble into rodlike aggregates that form the phase once the concentration exceeds about 0.1 M. The uniform surface alignment of the N phase is achieved by buffed polyimide layers. According to the light absorption anisotropy data, the molecular planes are on average perpendicular to the aggregate axes and thus to the nematic director. We determined the birefringence of these materials in the N and biphasic N-isotropic (I) regions and found it to be negative and significantly lower in the absolute value as compared to the birefringence of typical thermotropic low-molecular-weight nematic materials. In the absorbing materials Blue 27 and Violet 20, the wavelength dependence of birefringence is nonmonotonic because of the effect of anomalous dispersion near the absorption bands. We describe positive and negative tactoids formed as the nuclei of the new phase in the biphasic N-I region (which is wide in all three materials studied). Finally, we determined the scalar order parameter of the phase of Blue 27 and found it to be relatively high, in the range 0.72-0.79, which puts the finding into the domain of general validity of the Onsager model. However, the observed temperature dependence of the scalar order parameter points to the importance of factors not accounted for in the athermal Onsager model, such as interaggregate interactions and the temperature dependence of the aggregate length.

  8. Kernel parameter dependence in spatial factor analysis

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg

    2010-01-01

    feature space via the kernel function and then performing a linear analysis in that space. In this paper we shall apply a kernel version of maximum autocorrelation factor (MAF) [7, 8] analysis to irregularly sampled stream sediment geochemistry data from South Greenland and illustrate the dependence...

  9. Scaling of crystal field parameters between Pd{sub 2}REIn and Pd{sub 2}RESn

    Energy Technology Data Exchange (ETDEWEB)

    Babateen, M. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Neumann, K.U. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Ziebeck, K.R.A. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom)

    1995-02-09

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd{sub 2}REIn and Pd{sub 2}RESn (RE=rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation. ((orig.)).

  10. Purification, crystallization and preliminary X-ray analysis of the membrane-bound [NiFe] hydrogenase from Allochromatium vinosum

    Energy Technology Data Exchange (ETDEWEB)

    Kellers, Petra; Ogata, Hideaki; Lubitz, Wolfgang, E-mail: lubitz@mpi-muelheim.mpg.de [Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr (Germany)

    2008-08-01

    This article describes the first successful crystallization of a membrane-bound [NiFe] hydrogenase isolated from a photosynthetic organism (A. vinosum). The crystals obtained produced diffraction patterns up to 2.5 Å resolution. The membrane-bound [NiFe] hydrogenase is a unique metalloprotein that is able to catalyze the reversible oxidation of hydrogen to protons and electrons during a complex reaction cycle. The [NiFe] hydrogenase was isolated from the photosynthetic purple sulfur bacterium Allochromatium vinosum and its crystallization and preliminary X-ray analysis are reported. It was crystallized by the hanging-drop vapour-diffusion method using sodium citrate and imidazole as crystallization agents. The crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 205.00, b = 217.42, c = 120.44 Å. X-ray diffraction data have been collected to 2.5 Å resolution.

  11. Optimization of control parameters of CdZnTe ACRT-Bridgman single crystal growth

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Liu Juncheng, Jie Wanqi. Modeling Ekman flow during the ACRT process with marked particals, J. Cryst. Growth, 1998, 183: 140-149.[27]Yeckel, A., Derby, J. J., Effect of accelerated crucible rotation on melt composition in high-pressure vertical Bridgman growth of cadmium zinc telluride, J. Cryst. Growth, 2000, 209: 734-750.[28]Sen, S., Konkel, W. H.,Tighe, S. J. et al., Crystal growth of large-area single-crystal CdTe and CdZnTe by the computer-controlled vertical modified-Bridgman process, J. Cryst. Growth, 1988, 86: 111-117.[29]Rudolph, P., Muhlberg, M., Basic problems of vertical Bridgman growth of CdTe, Mater. Sci. Eng. B, 1993, 16: 8-16.[30]Aslam, N., Jones, E., Noakes, T. C. Q. et al., The diffusion of zinc in cadmium telluride, J. Cryst. Growth, 1992,117: 249-253.[31]Liu Juncheng. Effects of ACRT forced convection on heat and mass transportation of directional solidification, Progress in Natural Science, 2003, 13(12): 1293-1300.[32]Liu Xiaohua, Jie Wanqi, Zhou Yaohe, Numerical analysis on Hg1-xCdxTe growth by ACRT-VBM, J. Cryst. Growth, 2000, 209: 751-762.[33]Liu Xiaohua, Jie Wanqi, Zhou Yaohe, Numerical analysis of Cd1-xZnxTe crystal growth by the vertical Bridgman method using the accelerated crucible rotation technique, J. Cryst. Growth, 2000, 219: 22-31.[34]Yeckel, A., Derby, J. J., Buoyancy and rotation in small-scale vertical Bridgman growth of cadmium zinc telluride using accelerated crucible rotation, J. Cryst. Growth, 2001, 233: 599-608.

  12. Measuring parameters of large-aperture crystals used for generating optical harmonics

    Energy Technology Data Exchange (ETDEWEB)

    English, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hibbard, R. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Michie, R. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wegner, P. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Auerbach, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Norton, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Summers, M. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Perfect, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-23

    The purpose of this project was to develop tools for understanding the influence of crystal quality and crystal mounting on harmonic-generation efficiency at high irradiance. Measuring the homogeneity of crystals interferometrically, making detailed physics calculations of conversion efficiency, performing finite- element modeling of mounted crystals, and designing a new optical metrology tool were key elements in obtaining that understanding. For this work, we used the following frequency-tripling scheme: type I second- harmonic generation followed by type II sum-frequency mixing of the residual fundamental and the second harmonic light. The doubler was potassium dihydrogen phosphate (KDP), and the tripler was deuterated KDP (KD*P). With this scheme, near-infrared light (1053 nm) can be frequency tripled (to 351 nm) at high efficiency (theoretically >90%) for high irradiance (>3 GW/cm²). Spatial variations in the birefringence of the large crystals studied here (37 to 41 cm square by about 1 cm thick) imply that the ideal phase-matching orientation of the crystal with respect to the incident laser beam varies across the crystal. We have shown that phase-measuring interferometry can be used to measure these spatial variations. We observed transmitted wavefront differences between orthogonally polarized interferograms of {lambda}/50 to {lambda}/100, which correspond to index variations of order 10-6. On some plates that we measured, the standard deviation of angular errors is 22-23 µrad; this corresponds to a 1% reduction in efficiency. Because these conversion crystals are relatively thin, their surfaces are not flat (deviate by k2.5 urn from flat). A crystal is mounted against a precision-machined surface that supports the crystal on four edges. This mounting surface is not flat either (deviates by +2.5 µm from flat). A retaining flange presses a compliant element against the crystal. The load thus applied near the edges of the crystal surface holds

  13. Chemical Bond Analysis of Single Crystal Growth of Magnesium Oxide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Starting from the crystallographic structure of magnesium oxide (MgO), both the chemical bond model of solids and Pauling's third rule (polyhedral sharing rule) were employed to quantitatively analyze the chemical bonding structure of constituent atoms and single crystal growth. Our analytical results show that MgO single crystals prefer to grow along the direction and the growth rate of the {100} plane is the slowest one. Therefore, the results show that the {100} plane of MgO crystals can be the ultimate morphology face, which is in a good agreement with our previous experimental results. The study indicate that the structure analysis is an effective tool to control the single-crystal growth.

  14. Ab-initio calculations of Judd–Ofelt intensity parameters for transitions between crystal-field levels

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Jun, E-mail: wenjunkd@mail.ustc.edu.cn [School of Physics and Electric Engineering, Anqing Normal University, Anqing 246011 (China); Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Reid, Michael F. [Department of Physics and Astronomy and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, PB4800 Christchurch (New Zealand); Ning, Lixin [Department of Physics, Anhui Normal University, Wuhu 241000 (China); Zhang, Jie [School of Physics and Electric Engineering, Anqing Normal University, Anqing 246011 (China); Zhang, Yongfan [Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); Duan, Chang-Kui; Yin, Min [Department of Physics, University of Science and Technology of China, Hefei 230026 (China)

    2014-08-01

    Wavefunction-based ab-initio calculations of the electric-dipole moments of 4f{sup N}–4f{sup N} transitions of lanthanide ions are performed to extract the A{sub tp}{sup λ} intensity parameters. The extraction method is an extension of our earlier calculations of crystal-field (CF) parameters for lanthanide ions in crystals. The CASSCF/RASSI-SO (Complete-Active-Space Self-Consistent-Field/Restricted-Active-Space State-Interaction Spin-Orbit) calculations have been carried out on the chosen model system of CaF{sub 2}: Ce{sup 3+} with an interstitial fluoride ion (F{sub i}{sup −}) on z-axis (Ce{sup 3+} ion occupying the C{sub 4v} symmetry site). In consideration of the site symmetry and the coordination situation of Ce{sup 3+} ion at C{sub 4v} site in CaF{sub 2} as well as the superposition model (SM), the calculated intensity parameters for Ce{sup 3+} ion can be classified into three categories, and detailed discussions are then given. - Highlights: • Extraction of transition intensity parameters from ab-initio calculations. • CASSCF/RASSI-SO calculations are performed for Ce{sup 3+}-doped CaF{sub 2} crystal (C{sub 4v} case). • Extracted parameters are analyzed and compared with experiment and other calculation.

  15. Studies of the optical spectra and spin-Hamiltonian parameters for the trivalent ytterbium ions in lithium yttrium fluoride crystals

    Science.gov (United States)

    Feng, W. L.; Han, Z.; Zhong, Y. C.

    In this paper, the crystal field (CF) levels and spin-Hamiltonian (SH) parameters (g factors g∥ and g⊥ and hyperfine structure constants A∥ and A⊥) of the rare-earth ion Yb3+ in lithium yttrium fluoride crystals are calculated under D2d point symmetry assumption. Two main methods are used in the calculation to study the SH parameters: one is the perturbation theory method and the other is the complete diagonalization (energy matrix) method (CDM). Comparing the calculated results with the experimental data, we can see that the CDM is more effective to calculate the SH parameters. In addition, the CF J-mixing of all excited-state multiplets into the ground-state multiplet 2F7/2 is considered. The validity of the calculated results is discussed.

  16. Research on crystal growth by using pressure as a control parameter; Atsuryoku seigyo ni yoru kessho seicho ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-31

    This research project aims to establish a technique for crystal growth using pressure as a principal control parameter, and combining it with a microgravity condition, to develop a novel process material fabrication. Since the solubility of materials depends on pressure, it is possible to control a supersaturated condition for crystal growth by changing pressure. The growth condition can be controlled precisely, which is not possible by conventional methods that vary temperature and other factors. On the other hand, because a concentration diffusing field is formed autonomically around crystals in association with their growth, density convection is generated under gravity as a result of difference in the concentrations, making the growth conditions severely complex and uncontrollable. Ideal crystal growth condition control may be possible if the pressure control is performed under micro-gravity by which generation of the density convection can be suppressed. Realization has been achieved on in-situ observation by using high-magnification microscope which uses a diamond anvil cell, development of a hydraulic type optic pressure cell, and a high- speed crystal growing technology by means of pressure control utilizing the cell. New findings were also obtained on effects of pressure on crystal forms, and the pressure induced solid phase transfer mechanism. 67 refs., 49 figs., 3 tabs.

  17. Isolation, crystallization and preliminary crystallographic analysis of Salmonella typhimurium uridine phosphorylase crystallized with 2,2′-anhydrouridine

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, Vladimir I.; Lashkov, Alexander A.; Gabdoulkhakov, Azat G.; Pavlyuk, Bogdan Ph. [A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninskiy Prospect 59, 119333 Moscow (Russian Federation); Kachalova, Galina S. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya Street 3, 142290 Pushchino, Moscow Region (Russian Federation); Betzel, Christian [Institute fur Biochemie und Lebensmittelchemie, University of Hamburg, c/o DESY, Building 22, Notkestrasse 85, 22604 Hamburg (Germany); Morgunova, Ekaterina Yu.; Zhukhlistova, Nadezhda E.; Mikhailov, Al’bert M., E-mail: amm@ns.crys.ras.ru [A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninskiy Prospect 59, 119333 Moscow (Russian Federation)

    2007-10-01

    S. typhimurium uridine phosphorylase has been isolated and crystallized in the presence of ligand. Uridine phosphorylase (UPh; EC 2.4.2.3) is a member of the pyrimidine nucleoside phosphorylase family of enzymes which catalyzes the phosphorolytic cleavage of the C—N glycoside bond of uridine, with the formation of ribose 1-phosphate and uracil. This enzyme has been shown to be important in the activation and catabolism of fluoropyrimidines. Modulation of its enzymatic activity may affect the therapeutic efficacy of chemotherapeutic agents. The structural investigation of the bacterial uridine phosphorylases, both unliganded and complexed with substrate/product analogues and inhibitors, may help in understanding the catalytic mechanism of the phosphorolytic cleavage of uridine. Salmonella typhimurium uridine phosphorylase has been crystallized with 2,2′-anhydrouridine. X-ray diffraction data were collected to 2.15 Å. Preliminary analysis of the diffraction data indicates that the crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 88.52, b = 123.98, c = 133.52 Å. The solvent content is 45.51%, assuming the presence of one hexamer molecule per asymmetric unit.

  18. Spectroscopic analysis of LYSO:Ce crystals

    Science.gov (United States)

    Martins, A. F.; Carreira, J. F. C.; Rodrigues, J.; Sedrine, N. Ben; Castro, I. F. C.; Correia, P. M. M.; Veloso, J. F. C. A.; Rino, L.; Monteiro, T.

    2017-02-01

    Rare earth orthosilicates are among the most widely used scintillator materials in the last decades. Particularly, lutetium-yttrium oxyorthosilicate (LYSO) is known to exhibit great potentialities in the field of radiation detectors for medical imaging. Consequently, an in-depth knowledge of the material properties is of utmost interest for the mentioned applications. In this work the spectroscopic properties of commercial cerium doped lutetium-yttrium oxyorthosilicate crystals (LYSO:Ce) were investigated by Raman spectroscopy, steady state photoluminescence, photoluminescence excitation and time resolved photoluminescence. Site selective excitation was used under steady state (325 nm) and pulsed (266 nm) conditions to separately investigate the temperature dependence of the 5d → 4f Ce1 and Ce2 luminescence, allowing to establish the thermal quenching dependence of the Ce2 optical center. In the case of the Ce1 optical center, a luminescence quantum efficiency of 78% was obtained from 14 K to room temperature with 266 nm photon excitation.

  19. First-principles calculation of crystal field parameters of Dy ions substituted for Nd in Nd-Fe-B magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, S; Moriya, H; Tsuchiura, H; Sakuma, A [Department of Applied Physics, Tohoku University, Sendai 980-8579 (Japan); Divis, M [Department of Condensed Matter, Charles University, FMF, Prague (Czech Republic); Novak, P, E-mail: tanaka@olive.apph.tohoku.ac.jp [Institute of Physics of ASCR, Cukrovarnicka 10, 162 53 Prague 6 (Czech Republic)

    2011-01-01

    We study the electronic structures of crystalline Nd{sub 2}Fe{sub 14}B, Dy{sub 2}Fe{sub 14}B and Dy-doped Nd-Fe-B, and estimate the crystal field parameter A{sup 0}{sub 2}(r{sup 2}) of the rare earth ions of these systems based on the first principles calculations. We find that the crystal field of the Dy ions is appreciably insensitive to its crystallographic location than that of Nd ions.

  20. Sensitivity analysis of soil parameters based on interval

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Interval analysis is a new uncertainty analysis method for engineering struc-tures. In this paper, a new sensitivity analysis method is presented by introducing interval analysis which can expand applications of the interval analysis method. The interval anal-ysis process of sensitivity factor matrix of soil parameters is given. A method of parameter intervals and decision-making target intervals is given according to the interval analysis method. With FEM, secondary developments are done for Marc and the Duncan-Chang nonlinear elastic model. Mutual transfer between FORTRAN and Marc is implemented. With practial examples, rationality and feasibility are validated. Comparison is made with some published results.

  1. Crystallization and preliminary crystallographic analysis of human glycosylated haemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Syakhovich, Vitaly E. [Department of Biochemistry and Biophysics, International Sakharov Environmental University, Dolgobrodskaya St 23, 220009 Minsk (Belarus); Saraswathi, N. T.; Ruff, Marc, E-mail: ruff@igbmc.u-strasbg.fr [Département de Biologie et Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, BP 10142, 67404 Illkirch (France); Bokut, Sergey B. [Department of Biochemistry and Biophysics, International Sakharov Environmental University, Dolgobrodskaya St 23, 220009 Minsk (Belarus); Moras, Dino [Département de Biologie et Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, 1 Rue Laurent Fries, BP 10142, 67404 Illkirch (France); Department of Biochemistry and Biophysics, International Sakharov Environmental University, Dolgobrodskaya St 23, 220009 Minsk (Belarus)

    2006-02-01

    Non enzymatic modification of haemoglobin by glucose plays an important role in diabetes pathogenesis. Here the purification, characterization and crystallization of human glycosylated haemoglobin are reported. Human glycosylated haemoglobin A{sub 1C} is a stable minor variant formed in vivo by post-translational modification of the main form of haemoglobin by glucose. Crystals of oxyHbA{sub 1C} were obtained using the hanging-drop vapour-diffusion method and PEG as precipitant. The diffraction pattern of the crystal extends to a resolution of 2.3 Å at 120 K. The crystals belong to space group C2, with unit-cell parameters a = 237.98, b = 59.27, c = 137.02 Å, α = 90.00, β = 125.40, γ = 90.00°. The presence of two and a half molecules per asymmetric unit gives a crystal volume per protein weight (V{sub M}) of 9.70 Å{sup 3} Da{sup −1} and a solvent content of 49%.

  2. Crystallization and preliminary X-ray diffraction analysis of restriction endonuclease EcoRII

    Science.gov (United States)

    Karpova, E. A.; Meehan, E.; Pusey, M. L.; Chen, L.

    1999-01-01

    Crystals of the restriction endonuclease EcoRII have been obtained by the vapor-diffusion technique in the presence of ammonium sulfate or polyethylene glycol. The best crystals were grown with ammonium sulfate as a precipitant. Crystals with dimensions of up to 0.6 x 0. 6 x 0.6 mm have been observed. The crystals diffract to about 4.0 A resolution at a cryo-temperature of 100 K using a rotating-anode X-ray source and a Rigaku R-AXIS IV imaging-plate detector. The space group has been determined to be either I23 or I2(1)3, with unit-cell parameters a = b = c = 160.3 A, alpha = beta = gamma = 90 degrees. The crystal asymmetric unit contains two protein molecules, and self-rotation function analysis shows a pseudo-twofold symmetry relating the two monomers. Attempts to improve the resolution of crystal diffraction and to search for heavy-atom derivatives are under way.

  3. Advancing sensitivity analysis to precisely characterize temporal parameter dominance

    Science.gov (United States)

    Guse, Björn; Pfannerstill, Matthias; Strauch, Michael; Reusser, Dominik; Lüdtke, Stefan; Volk, Martin; Gupta, Hoshin; Fohrer, Nicola

    2016-04-01

    Parameter sensitivity analysis is a strategy for detecting dominant model parameters. A temporal sensitivity analysis calculates daily sensitivities of model parameters. This allows a precise characterization of temporal patterns of parameter dominance and an identification of the related discharge conditions. To achieve this goal, the diagnostic information as derived from the temporal parameter sensitivity is advanced by including discharge information in three steps. In a first step, the temporal dynamics are analyzed by means of daily time series of parameter sensitivities. As sensitivity analysis method, we used the Fourier Amplitude Sensitivity Test (FAST) applied directly onto the modelled discharge. Next, the daily sensitivities are analyzed in combination with the flow duration curve (FDC). Through this step, we determine whether high sensitivities of model parameters are related to specific discharges. Finally, parameter sensitivities are separately analyzed for five segments of the FDC and presented as monthly averaged sensitivities. In this way, seasonal patterns of dominant model parameter are provided for each FDC segment. For this methodical approach, we used two contrasting catchments (upland and lowland catchment) to illustrate how parameter dominances change seasonally in different catchments. For all of the FDC segments, the groundwater parameters are dominant in the lowland catchment, while in the upland catchment the controlling parameters change seasonally between parameters from different runoff components. The three methodical steps lead to clear temporal patterns, which represent the typical characteristics of the study catchments. Our methodical approach thus provides a clear idea of how the hydrological dynamics are controlled by model parameters for certain discharge magnitudes during the year. Overall, these three methodical steps precisely characterize model parameters and improve the understanding of process dynamics in hydrological

  4. Electrochemical degradation of crystal violet with BDD electrodes: effect of electrochemical parameters and identification of organic by-products.

    Science.gov (United States)

    Palma-Goyes, Ricardo E; Guzmán-Duque, Fernando L; Peñuela, Gustavo; González, Ignacio; Nava, Jose L; Torres-Palma, Ricardo A

    2010-09-01

    This paper explores the applicability of electrochemical oxidation on a triphenylmethane dye compound model, hexamethylpararosaniline chloride (or crystal violet, CV), using BDD anodes. The effect of the important electrochemical parameters: current density (2.5-15 m A cm(-2)), dye concentration (33-600 mg L(-1)), sodium sulphate concentration (7.1-50.0 g L(-1)) and initial pH (3-11) on the efficiency of the electrochemical process was evaluated. The results indicated that while the current density was lower than the limiting current density, no side products (hydrogen peroxide, peroxodisulphate, ozone and chlorinated oxidizing compounds) were generated and the degradation, through OH radical attack, occurred with high efficiency. Analysis of intermediates using GC-MS investigation identified several products: N-methylaniline, N,N-dimethylaniline, 4-methyl-N,N-dimethylaniline, 4-methyl-N-methylaniline, 4-dimethylaminophenol, 4-dimethylaminobenzoic acid, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino) diphenylmethane, 4-(4-dimethylaminophenyl)-N,N-dimethylaniline, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino) benzophenone. The presence of these aromatic structures showed that the main CV degradation pathway is related to the reaction of CV with the OH radical. Under optimal conditions, practically 100% of the initial substrate and COD were eliminated in approximately 35 min of electrolysis; indicating that the early CV by-products were completely degraded by the electrochemical system. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  5. Crystallization and preliminary X-ray analysis of Rv1674c from Mycobacterium tuberculosis

    Science.gov (United States)

    Li, Jincheng; Wang, Xudong; Gong, Weimin; Niu, Chunyan; Zhang, Min

    2015-01-01

    Adaptations to hypoxia play an important role in Mycobacterium tuberculosis pathogenesis. Rv0324, which contains an HTH DNA-binding domain and a rhodanese domain, is one of the key transcription regulators in response to hypoxia. M. tuberculosis Rv1674c is a homologue of Rv0324. To understand the interdomain interaction and regulation of the HTH domain and the rhodanese domain, recombinant Rv1674c protein was purified and crystallized by the vapour-diffusion method. The crystals diffracted to 2.25 Å resolution. Preliminary diffraction analysis suggests that the crystals belonged to space group P3121 or P3221, with unit-cell parameters a = b = 67.8, c = 174.5 Å, α = β = 90, γ = 120°. The Matthews coefficient was calculated to be 2.44 Å3 Da−1, assuming that the crystallographic asymmetric unit contains two protein molecules. PMID:25760714

  6. Crystallization and initial X-ray diffraction analysis of human pyruvate dehydrogenase

    Science.gov (United States)

    Ciszak, E.; Korotchkina, L. G.; Hong, Y. S.; Joachimiak, A.; Patel, M. S.

    2001-01-01

    Human pyruvate dehydrogenase (E1) is a component enzyme of the pyruvate dehydrogenase complex. The enzyme catalyzes the irreversible decarboxylation of pyruvic acid and the rate-limiting reductive acetylation of the lipoyl moiety linked to the dihydrolipoamide acetyltransferase component of the pyruvate dehydrogenase complex. E1 is an alpha(2)beta(2) tetramer ( approximately 154 kDa). Crystals of this recombinant enzyme have been grown in polyethylene glycol 3350 using a vapor-diffusion method at 295 K. The crystals are characterized as orthorhombic, space group P2(1)2(1)2(1), with unit-cell parameters a = 64.2, b = 126.9, c = 190.2 A. Crystals diffracted to a minimum d spacing of 2.5 A. The asymmetric unit contains one alpha(2)beta(2) tetrameric E1 assembly; self-rotation function analysis showed a pseudo-twofold symmetry relating the two alphabeta dimers.

  7. Purification, crystallization and preliminary X-ray analysis of uridine phosphorylase from Salmonella typhimurium.

    Science.gov (United States)

    Dontsova, Mariya V; Savochkina, Yulia A; Gabdoulkhakov, Azat G; Baidakov, Sergey N; Lyashenko, Andrey V; Zolotukhina, Maria; Errais Lopes, Liubov; Garber, Mariya B; Morgunova, Ekaterina Yu; Nikonov, Stanislav V; Mironov, Alexandr S; Ealick, Steven E; Mikhailov, Al 'Bert M

    2004-04-01

    The structural udp gene encoding uridine phosphorylase (UPh) was cloned from the Salmonella typhimurium chromosome and overexpressed in Escherichia coli cells. S. typhimurium UPh (StUPh) was purified to apparent homogeneity and crystallized. The primary structure of StUPh has high homology to the UPh from E. coli, but the enzymes differ substantially in substrate specificity and sensitivity to the polarity of the medium. Single crystals of StUPh were grown using hanging-drop vapor diffusion with PEG 8000 as the precipitant. X-ray diffraction data were collected to 2.9 A resolution. Preliminary analysis of the diffraction data indicated that the crystal belonged to space group P6(1(5)), with unit-cell parameters a = 92.3, c = 267.5 A. The solvent content is 37.7% assuming the presence of one StUPh hexamer per asymmetric unit.

  8. Crystallization and preliminary X-ray diffraction analysis of West Nile virus

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Barbel; Plevka, Pavel; Kuhn, Richard J.; Rossmann, Michael G. (Purdue)

    2010-05-25

    West Nile virus, a human pathogen, is closely related to other medically important flaviviruses of global impact such as dengue virus. The infectious virus was purified from cell culture using polyethylene glycol (PEG) precipitation and density-gradient centrifugation. Thin amorphously shaped crystals of the lipid-enveloped virus were grown in quartz capillaries equilibrated by vapor diffusion. Crystal diffraction extended at best to a resolution of about 25 {angstrom} using synchrotron radiation. A preliminary analysis of the diffraction images indicated that the crystals had unit-cell parameters a {approx_equal} b {approx_equal} 480 {angstrom}, {gamma} = 120{sup o}, suggesting a tight hexagonal packing of one virus particle per unit cell.

  9. Investigations on nucleation, HRXRD, optical, piezoelectric, polarizability and Z-scan analysis of L-arginine maleate dihydrate single crystals

    Science.gov (United States)

    Sakthy Priya, S.; Alexandar, A.; Surendran, P.; Lakshmanan, A.; Rameshkumar, P.; Sagayaraj, P.

    2017-04-01

    An efficient organic nonlinear optical single crystal of L-arginine maleate dihydrate (LAMD) has been grown by slow evaporation solution technique (SEST) and slow cooling technique (SCT). The crystalline perfection of the crystal was examined using high-resolution X-ray diffractometry (HRXRD) analysis. Photoluminescence study confirmed the optical properties and defects level in the crystal lattice. Electromechanical behaviour was observed using piezoelectric co-efficient (d33) analysis. The photoconductivity analysis confirmed the negative photoconducting nature of the material. The dielectric constant and loss were measured as a function of frequency with varying temperature and vice-versa. The laser damage threshold (LDT) measurement was carried out using Nd:YAG Laser with a wavelength of 1064 nm (Focal length is 35 cm) and the obtained results showed that LDT value of the crystal is high compared to KDP crystal. The high laser damage threshold of the grown crystal makes it a potential candidate for second and higher order nonlinear optical device application. The third order nonlinear optical parameters of LAMD crystal is determined by open-aperture and closed-aperture studies using Z-scan technique. The third order linear and nonlinear optical parameters such as the nonlinear refractive index (n2), two photon absorption coefficient (β), Real part (Reχ3) and imaginary part (Imχ3) of third-order nonlinear optical susceptibility are calculated.

  10. The purification, crystallization and preliminary X-ray diffraction analysis of dihydrodipicolinate synthase from Clostridium botulinum

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Renwick C. J., E-mail: rdobson@unimelb.edu.au; Atkinson, Sarah C. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia); Gorman, Michael A. [St Vincents Institute, 9 Princes Street, Fitzroy, Victoria 3065 (Australia); Newman, Janet M. [CSIRO Division of Molecular and Health Technologies, 343 Royal Parade, Parkville, Victoria 3052 (Australia); Parker, Michael W. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia); St Vincents Institute, 9 Princes Street, Fitzroy, Victoria 3065 (Australia); Perugini, Matthew A. [Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010 (Australia); Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2008-03-01

    Dihydrodipicolinate synthase (DHDPS), an enzyme in the lysine-biosynthetic pathway, is a promising target for antibiotic development against pathogenic bacteria. Here, the expression, purification, crystallization and preliminary diffraction analysis of DHDPS from C. botulinum are reported. In recent years, dihydrodipicolinate synthase (DHDPS; EC 4.2.1.52) has received considerable attention from both mechanistic and structural viewpoints. This enzyme, which is part of the diaminopimelate pathway leading to lysine, couples (S)-aspartate-β-semialdehyde with pyruvate via a Schiff base to a conserved active-site lysine. In this paper, the expression, purification, crystallization and preliminary X-ray diffraction analysis of DHDPS from Clostridium botulinum, an important bacterial pathogen, are presented. The enzyme was crystallized in a number of forms, predominantly using PEG precipitants, with the best crystal diffracting to beyond 1.9 Å resolution and displaying P4{sub 2}2{sub 1}2 symmetry. The unit-cell parameters were a = b = 92.9, c = 60.4 Å. The crystal volume per protein weight (V{sub M}) was 2.07 Å{sup 3} Da{sup −1}, with an estimated solvent content of 41%. The structure of the enzyme will help guide the design of novel therapeutics against the C. botulinum pathogen.

  11. A topological analysis of charge densities in diamond, silicon and germanium crystals

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, Yu.A. [National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan); Okamura, F.P. [National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)

    1997-03-01

    The Hansen-Coppens multipole model of charge density has been fitted to highly accurate published experimental and theoretical structure factors for diamond, silicon and germanium crystals. Analysis of both model experimental and theoretical charge densities using the resulting model parameters was performed in terms of Bader`s topological theory. The general topology of the charge density appeared to be identical for all crystals, containing the four possible types of critical points of rank three, and no non-nuclear attractors between neighboring atoms were found within achieved accuracy. Theoretical and experimental values of charge density and its Laplacian show quantitative and semiquantitative agreement, respectively, at the critical points of model charge densities. For Ge crystals, such agreement is worse at the ring critical point. These results suggest the possibility of semiquantitative (within 10-30%) study of the topological characteristics of highly accurate X-ray charge densities of crystals displaying shared interatomic interactions. Comparative topological analysis of the chemical bond in this series of crystals is discussed in terms of the quantum topological theory. (orig.).

  12. Glaciological parameters of disruptive event analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bull, C.

    1980-04-01

    The possibility of complete glaciation of the earth is small and probably need not be considered in the consequence analysis by the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program. However, within a few thousand years an ice sheet may well cover proposed waste disposal sites in Michigan. Those in the Gulf Coast region and New Mexico are unlikely to be ice covered. The probability of ice cover at Hanford in the next million years is finite, perhaps about 0.5. Sea level will fluctuate as a result of climatic changes. As ice sheets grow, sea level will fall. Melting of ice sheets will be accompanied by a rise in sea level. Within the present interglacial period there is a definite chance that the West Antarctic ice sheet will melt. Ice sheets are agents of erosion, and some estimates of the amount of material they erode have been made. As an average over the area glaciated by late Quaternary ice sheets, only a few tens of meters of erosion is indicated. There were perhaps 3 meters of erosion per glaciation cycle. Under glacial conditions the surface boundary conditions for ground water recharge will be appreciably changed. In future glaciations melt-water rivers generally will follow pre-existing river courses. Some salt dome sites in the Gulf Coast region could be susceptible to changes in the course of the Mississippi River. The New Mexico site, which is on a high plateau, seems to be immune from this type of problem. The Hanford Site is only a few miles from the Columbia River, and in the future, lateral erosion by the Columbia River could cause changes in its course. A prudent assumption in the AEGIS study is that the present interglacial will continue for only a limited period and that subsequently an ice sheet will form over North America. Other factors being equal, it seems unwise to site a nuclear waste repository (even at great depth) in an area likely to be glaciated.

  13. Investigations on critical parameters, growth, structural and spectral studies of beta-alaninium picrate (BAP) single crystals

    Science.gov (United States)

    Shanthi, D.; Selvarajan, P.; Perumal, S.

    2014-12-01

    Beta-alaninium picrate (BAP) salt has been synthesized and the solubility of the synthesized sample in double distilled water was determined at different temperatures. Solution stability was studied by observing the metastable zone width by employing the polythermal method. Induction period values for different supersaturation ratios at room temperature were determined based on the isothermal method. The nucleation parameters such as critical radius, critical free energy change, interfacial tension, and nucleation rate have been estimated for BAP salt on the basis of the classical nucleation theory. The lattice parameters of the grown BAP crystal were determined using the x-ray diffraction (XRD) technique. The reflection planes of the sample were confirmed by the powder XRD study and diffraction peaks were indexed. Fourier transform infrared spectroscopy and Fourier transform-Raman studies were used to confirm the presence of various functional groups in the BAP crystal. The nonlinear optical property of the grown crystal was studied using the Kurtz-Perry powder technique. UV-visible spectral studies were carried out to understand optical transparency and the type of band gap of the grown BAP crystal.

  14. THEORETICAL RESEARCH OF THE OPTICAL SPECTRA AND EPR PARAMETERS FOR Cs2NaYCl6:Dy3+ CRYSTAL

    Science.gov (United States)

    Dong, Hui-Ning; Dong, Meng-Ran; Li, Jin-Jin; Li, Deng-Feng; Zhang, Yi

    2013-09-01

    The calculated EPR parameters are in reasonable agreement with the observed values. The important material Cs2NaYCl6 doped with rare earth ions have received much attention because of its excellent optical and magnetic properties. Based on the superposition model, in this paper the crystal field energy levels, the electron paramagnetic resonance parameters g factors of Dy3+ and hyperfine structure constants of 161Dy3+ and 163Dy3+ isotopes in Cs2NaYCl6 crystal are studied by diagonalizing the 42 × 42 energy matrix. In the calculations, the contributions of various admixtures and interactions such as the J-mixing, the mixtures among the states with the same J-value, and the covalence are all considered. The calculated results are in reasonable agreement with the observed values. The results are discussed.

  15. Features in simulation of crystal growth using the hyperbolic PFC equation and the dependence of the numerical solution on the parameters of the computational grid

    Energy Technology Data Exchange (ETDEWEB)

    Starodumov, Ilya [Laboratory of Multi-Scale Mathematical Modeling, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Kropotin, Nikolai [AO NPO MKM, Ilfata Zakirova st. 24, 426000 Izhevsk (Russian Federation)

    2016-08-10

    We investigate the three-dimensional mathematical model of crystal growth called PFC (Phase Field Crystal) in a hyperbolic modification. This model is also called the modified model PFC (originally PFC model is formulated in parabolic form) and allows to describe both slow and rapid crystallization processes on atomic length scales and on diffusive time scales. Modified PFC model is described by the differential equation in partial derivatives of the sixth order in space and second order in time. The solution of this equation is possible only by numerical methods. Previously, authors created the software package for the solution of the Phase Field Crystal problem, based on the method of isogeometric analysis (IGA) and PetIGA program library. During further investigation it was found that the quality of the solution can strongly depends on the discretization parameters of a numerical method. In this report, we show the features that should be taken into account during constructing the computational grid for the numerical simulation.

  16. Features in simulation of crystal growth using the hyperbolic PFC equation and the dependence of the numerical solution on the parameters of the computational grid

    Science.gov (United States)

    Starodumov, Ilya; Kropotin, Nikolai

    2016-08-01

    We investigate the three-dimensional mathematical model of crystal growth called PFC (Phase Field Crystal) in a hyperbolic modification. This model is also called the modified model PFC (originally PFC model is formulated in parabolic form) and allows to describe both slow and rapid crystallization processes on atomic length scales and on diffusive time scales. Modified PFC model is described by the differential equation in partial derivatives of the sixth order in space and second order in time. The solution of this equation is possible only by numerical methods. Previously, authors created the software package for the solution of the Phase Field Crystal problem, based on the method of isogeometric analysis (IGA) and PetIGA program library. During further investigation it was found that the quality of the solution can strongly depends on the discretization parameters of a numerical method. In this report, we show the features that should be taken into account during constructing the computational grid for the numerical simulation.

  17. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    Science.gov (United States)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-08-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  18. Quadratic nonlinear optical parameters of 7% MgO-doped LiNbO3 crystal

    Science.gov (United States)

    Kulyk, B.; Kapustianyk, V.; Figà, V.; Sahraoui, B.

    2016-06-01

    Pure and 7% MgO-doped lithium niobate (LiNbO3) single crystals were grown by the Czochralski technique. The shift of optical absorption edge in 7% MgO-doped crystal in direction of shorter wavelength compared to undoped crystal was observed. The second harmonic generation measurements of 7% MgO-doped LiNbO3 crystal were performed at room temperature by means of the rotational Maker fringe technique using Nd:YAG laser generating at 1064 nm in picoseconds regime. Experimentally obtained value of nonlinear optical coefficient d33 for 7% MgO-doped LiNbO3 was found to be less than for undoped crystal but higher than for 5% MgO-doped. I-type phase-matched second harmonic generation was achieved and the value of phase-matched angle was calculated. High quadratic nonlinearity together with tolerance to intensive laser irradiation makes 7% MgO-doped LiNbO3 crystal interesting for application in optoelectronics.

  19. Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis

    Directory of Open Access Journals (Sweden)

    Christian Held

    2013-01-01

    Full Text Available Introduction: Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. Methods: In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline′s modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. Results: This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. Conclusion: The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

  20. Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis

    Science.gov (United States)

    Held, Christian; Nattkemper, Tim; Palmisano, Ralf; Wittenberg, Thomas

    2013-01-01

    Introduction: Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. Methods: In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline's modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. Results: This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. Conclusion: The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum. PMID:23766941

  1. Back-analysis for Determining the Rheological Parameter of Rock

    Institute of Scientific and Technical Information of China (English)

    Xu Wenhuan; Zhu Dayong

    1994-01-01

    In this paper,a new method of back analysis for determmning the parameters of rheological surrounding rock is proposed. This method is based on the elasticviscoelastic correspondence principle, and the theological parameters are back analyzed from the measured displacemenrs during construction of the tunnel.A numerical exampie proves that the proposed method is applicanle to engineering practice.

  2. Lattice variation and thermal parameters of NiMg1–SO4 7H2O single crystals

    Indian Academy of Sciences (India)

    M Theivanayagom; C Mahadevan

    2001-10-01

    NiMg1–SO4.7H2O single crystals were grown by the slow evaporation method from aqueous solutions. Density was measured by the floatation method. X-ray diffraction data were collected for powder samples and used for the estimation of lattice variation and thermal parameters like Debye–Waller factor, mean-square amplitude of vibration and Debye temperature. Lattice volumes approximately obey a relation similar to Retger’s rule. Values of thermal parameters do not follow any particular order with composition. The results obtained are reported.

  3. Studies on Pidotimod Enantiomers With Chiralpak-IA: Crystal Structure, Thermodynamic Parameters and Molecular Docking.

    Science.gov (United States)

    Dou, Xiaorui; Su, Xin; Wang, Yue; Chen, Yadong; Shen, Weiyang

    2015-11-01

    Pidotimod, a synthetic dipeptide, has two chiral centers with biological and immunological activity. Its enantiomers were characterized by x-ray crystallographic analysis. A chiral stationary phase (CSP) Chiralpak-IA based on amylose derivatized with tris-(3, 5-dimethylphenyl carbamate) was used to separate pidotimod enantiomers. The mobile phase was prepared in a ratio of 35:65:0.2 of methyl-tert-butyl-ether and acetonitrile trifluoroaceticacid. In addition, thermodynamics and molecular docking methods were used to explain the enantioseparation mechanism by Chiralpak-IA. Thermodynamic studies were carried out from 10 to 45 °C. In general, both retention and enantioselectivity decreased as the temperature increased. Thermodynamic parameters indicate that the interaction force between the pidotimod enantiomer (4S, 2'R) and IA CSP is stronger and their complex model is more stable. According to GOLD molecular docking simulation, Van der Waals force is the leading cause of pidotimod enantiomers separation by IA CSP.

  4. Relationship between thermodynamic parameter and thermodynamic scaling parameter for orientational relaxation time for flip-flop motion of nematic liquid crystals.

    Science.gov (United States)

    Satoh, Katsuhiko

    2013-03-07

    Thermodynamic parameter Γ and thermodynamic scaling parameter γ for low-frequency relaxation time, which characterize flip-flop motion in a nematic phase, were verified by molecular dynamics simulation with a simple potential based on the Maier-Saupe theory. The parameter Γ, which is the slope of the logarithm for temperature and volume, was evaluated under various conditions at a wide range of temperatures, pressures, and volumes. To simulate thermodynamic scaling so that experimental data at isobaric, isothermal, and isochoric conditions can be rescaled onto a master curve with the parameters for some liquid crystal (LC) compounds, the relaxation time was evaluated from the first-rank orientational correlation function in the simulations, and thermodynamic scaling was verified with the simple potential representing small clusters. A possibility of an equivalence relationship between Γ and γ determined from the relaxation time in the simulation was assessed with available data from the experiments and simulations. In addition, an argument was proposed for the discrepancy between Γ and γ for some LCs in experiments: the discrepancy arises from disagreement of the value of the order parameter P2 rather than the constancy of relaxation time τ1(*) on pressure.

  5. Purification, crystallization and preliminary X-ray diffraction analysis of water-soluble chlorophyll-binding protein from Chenopodium album

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, Takayuki [Department of Bimolecular Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan); Ohshima, Shigeru [Department of Environmental Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan); Uchida, Akira, E-mail: auchida@biomol.sci.toho-u.ac.jp [Department of Bimolecular Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan)

    2007-09-01

    A water-soluble chlorophyll-binding protein with photoconvertibility from C. album was extracted, purified and crystallized in a darkroom. The crystal diffracted to around 2.0 Å resolution. A water-soluble chlorophyll-binding protein (WSCP) with photoconvertibility from Chenopodium album was extracted, purified and crystallized in a darkroom. Green crystals suitable for data collection appeared in about 10 d. A native data set was collected to 2.0 Å resolution at 100 K. The space group of the crystal was determined to be orthorhombic I222 or I2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 48.13, b = 60.59, c = 107.21 Å. Preliminary analysis of the X-ray data indicated that there is one molecule per asymmetric unit.

  6. Parameter estimation and error analysis in environmental modeling and computation

    Science.gov (United States)

    Kalmaz, E. E.

    1986-01-01

    A method for the estimation of parameters and error analysis in the development of nonlinear modeling for environmental impact assessment studies is presented. The modular computer program can interactively fit different nonlinear models to the same set of data, dynamically changing the error structure associated with observed values. Parameter estimation techniques and sequential estimation algorithms employed in parameter identification and model selection are first discussed. Then, least-square parameter estimation procedures are formulated, utilizing differential or integrated equations, and are used to define a model for association of error with experimentally observed data.

  7. Back analysis of mechanical parameters of roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam displacements.During the process of back analysis,the initial samples of parameters were designed with uniform design method.Then,a transversely isotropic model of RCCD was established by MSC.Marc software.Through this model,training samples of LSSVM model could be obtained.And then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was established.Finally,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using PLS.By inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be obtained.The example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

  8. Unscented Kalman filter with parameter identifiability analysis for the estimation of multiple parameters in kinetic models

    Directory of Open Access Journals (Sweden)

    Baker Syed

    2011-01-01

    Full Text Available Abstract In systems biology, experimentally measured parameters are not always available, necessitating the use of computationally based parameter estimation. In order to rely on estimated parameters, it is critical to first determine which parameters can be estimated for a given model and measurement set. This is done with parameter identifiability analysis. A kinetic model of the sucrose accumulation in the sugar cane culm tissue developed by Rohwer et al. was taken as a test case model. What differentiates this approach is the integration of an orthogonal-based local identifiability method into the unscented Kalman filter (UKF, rather than using the more common observability-based method which has inherent limitations. It also introduces a variable step size based on the system uncertainty of the UKF during the sensitivity calculation. This method identified 10 out of 12 parameters as identifiable. These ten parameters were estimated using the UKF, which was run 97 times. Throughout the repetitions the UKF proved to be more consistent than the estimation algorithms used for comparison.

  9. Unscented Kalman filter with parameter identifiability analysis for the estimation of multiple parameters in kinetic models.

    Science.gov (United States)

    Baker, Syed Murtuza; Poskar, C Hart; Junker, Björn H

    2011-10-11

    In systems biology, experimentally measured parameters are not always available, necessitating the use of computationally based parameter estimation. In order to rely on estimated parameters, it is critical to first determine which parameters can be estimated for a given model and measurement set. This is done with parameter identifiability analysis. A kinetic model of the sucrose accumulation in the sugar cane culm tissue developed by Rohwer et al. was taken as a test case model. What differentiates this approach is the integration of an orthogonal-based local identifiability method into the unscented Kalman filter (UKF), rather than using the more common observability-based method which has inherent limitations. It also introduces a variable step size based on the system uncertainty of the UKF during the sensitivity calculation. This method identified 10 out of 12 parameters as identifiable. These ten parameters were estimated using the UKF, which was run 97 times. Throughout the repetitions the UKF proved to be more consistent than the estimation algorithms used for comparison.

  10. Study on Lattice Parameter Variance and Eutectic Reaction during Crystal Growth of Nd,Cr∶GSGG by Czochralksi Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During the crystal growth of Nd, Cr∶GSGG by Czochralski method, in some cases eutectic reaction occurred in the nether region of the crystal, and the boule was divided into two obvious different parts, which is upper Nd,Cr∶GSGG crystal and the nether coexisting Nd,Cr∶GSGG and GdScO3. By X-ray powder diffraction, the structure change of NdCr∶GSGG crystal of Φ 27 mm×120 mm with eutectic along its grown direction was studied. By the least square method and extrapolation function f=sinθ-sinθ1-t(t is an adjustable parameter), the lattice parameters of Nd,Cr∶GSGG and additional GdScO3 phase were computed. The results indicate that the lattice parameters of Nd,Cr∶GSGG increase along its growth direction, which changes from a=(1.25650±0.00007) nm of the top to (1.25798±0.00010) nm of the bottom. In the process of Nd,Cr∶GSGG growth, Gd3+ in Nd,Cr∶GSGG is partly replaced by Nd3+ with larger ionic radii, and the volatilization of Ga component results in its composition variance, which cause the lattice parameters increase along growth direction. In the eutectic section, there are the Nd,Cr∶GSGG and the second phase orthorhombic GdScO3. The lattice parameters of GdScO3 are a=0.5443±0.0007, b=0.5699±0.0005 and c=(0.7865±0.0009) nm, and that of Nd,Cr∶GSGG is (1.25798±0.00010) nm. In the final growth stage, excessive volatilization of Ga composition during the crystal growth causes the growth melt deflect of the Nd,Cr∶GSGG solid solution range seriously, and results in the eutectic reaction, and the outgrowth of Nd,Cr∶GSGG and GdScO3. So it is necessary to decrease the effect of gallium volatilization during the growth in order to avoid eutectic growth and obtain a high-quality Nd,Cr∶GSGG.

  11. Crystallization and preliminary crystallographic analysis of manganese lipoxygenase.

    Science.gov (United States)

    Wennman, Anneli; Oliw, Ernst H; Karkehabadi, Saeid

    2014-04-01

    Lipoxygenases constitute a family of nonhaem metal enzymes with catalytic iron or, occasionally, catalytic manganese. Lipoxygenases oxidize polyunsaturated fatty acids with position specificity and stereospecificity to hydroperoxides, which contribute to inflammation and the development of cancer. Little is known about the structural differences between lipoxygenases with Fe or Mn and the metal-selection mechanism. A Pichia pastoris expression system was used for the production of the manganese lipoxygenase of the take-all fungus of wheat, Gaeumannomyces graminis. The active enzyme was treated with α-mannosidase, purified to apparent homogeneity and subjected to crystal screening and X-ray diffraction. The crystals diffracted to 2.6 Å resolution and belonged to space group C2, with unit-cell parameters a = 226.6, b = 50.6, c = 177.92 Å, β = 91.70°.

  12. [Spectroscopic analysis of Nd:GGG laser crystal].

    Science.gov (United States)

    Zeng, Fan-ming; Zhang, Ying; Sun, Jing; Liu, Jing-he

    2009-05-01

    Neodymium-doped gadolinium gallium garnet (Nd:GGG)crystal is the best operation material of solid-state heat-capacity laser. In the present paper, Nd:GGG single crystal was grown by Czochralski (Cz) method. Fluorescence spectra and absorption spectra were measured. At the same time, the spectral parameters of Nd:GGG laser crystal were calculated by Judd-Ofelt theory, including absorption and emission cross-section, intensity parameters, radiative transition probability, fluorescence branch ratio and fluorescent lifetime. According to the measurement and calculation of absorption spectra, it is illustrated that the main absorption peak of Nd: GGG crystal was at near 808 nm, the absorption cross section of the main peak at 808 nm sigma abs, was equal to 4. 35 x 10(-20) cm2. The FWHM of absorption line-width was equal to 8 nm, and the absorption intensity became stronger with the increase in Nd3+ ions concentration. According to the measurement and calculation of fluorescence spectra, the fluorescence emission peak was at near 1062 nm, which corresponds to 4F(3/2) - 4(I(11/2) emission band of Nd3+ ions. The radiative transition probabilityof the main emission peak at 1062 nm A(jj') was equal to 1 832.01 s(-1). The fluorescence branch ratio betajj was equal to 45.07%. The fluorescence lifetime r was equal to 250 micros. The stimulated emission cross section sigma(lamda) was equal to 21.58 x 10(-20) cm2. The laser operationof 4F(3/2) - 4I(11/2) transition can be realized due to the larger fluorescence branch ratio and stimulated emission cross section

  13. Link between optical spectra, crystal-field parameters, and local environments of Eu3+ ions in Eu2O3-doped sodium disilicate glass

    Science.gov (United States)

    Qin, T.; Mountjoy, G.; Afify, N. D.; Reid, M. F.; Yeung, Y. Y.; Speghini, A.; Bettinelli, M.

    2011-09-01

    Rare-earth-doped glasses are key materials for optical technology due to the luminescent properties of 4fn ions. The crystal-field model describes the effect of local environment on transitions between 4f electrons. We present a detailed modeling study of the optical spectra of sodium disilicate glass, 33Na2O·67SiO2, doped with 0.2% and 1.0 mol% Eu2O3. This study uses very large molecular dynamics models with up to 100 Eu3+ ions, the superposition model for covalent and overlap effects on crystal-field parameters, and realistic values for homogeneous linewidth broadening. The simulated spectra are in reasonable agreement with experiment. The trends in 7FJ energy levels across different Eu3+ ion sites have been examined and a very detailed analysis is presented that looks at how features of the spectra are related to features of the local environment of Eu3+ ions. Increasing the crystal-field strength Stotal causes the 7F0 energy level to decrease and causes the splitting of 7FJ manifolds to increase, and this is due to increasing mixing of 4f wave functions. To a reasonable approximation the crystal-field strength components Sk depend on angular positions of ligands independently of distances to ligands. The former are seen to be more significant in determining Sk, which are closely related to the rotationally invariant bond-orientational order parameters Qk. The values of S2 are approximately linear in Q2, and the values of Q2 are higher for fivefold than sixfold coordinated rare-earth ions. These results can be of importance for efforts to enhance the local environment of rare-earth ions in oxide glasses for optical applications.

  14. Analysis of sagittal balance of ankylosing spondylitis using spinopelvic parameters.

    Science.gov (United States)

    Lee, Jung Sub; Suh, Kuen Tak; Kim, Jeung Il; Goh, Tae Sik

    2014-05-01

    Prospective study. To analyze sagittal spinopelvic parameters in ankylosing spondylitis (AS) patients. There are little data on the relationship between the sagittal spinopelvic parameters and AS. The study and control groups comprised 90 AS patients and 40 controls. Participants were classified into 3 groups: normal (n=40), sagittal balance (n=58), and sagittal imbalance (n=32) groups. All underwent lateral radiograph of the whole spine including hip joints. The radiographic parameters were sacral slope, pelvic tilting, pelvic incidence, overhang of S1, thoracic kyphosis, lumbar lordosis, and C7 plumbline. Statistical analysis was performed to identify significant differences between the 2 groups. Correlations between radiological parameters and symptoms were sought. AS patients and controls were found to be significantly different in terms of sagittal balance, sacral slope, pelvic tilt, pelvic incidence, S1 overhang, and lumbar lordosis. However, no significant difference was observed between these 2 groups for thoracic kyphosis (P>0.05). Of the 90 AS patients, 32 patients (5 women and 27 men) were assigned to the sagittal imbalance group and 58 (12 women and 46 men) to the sagittal balance group. There was a significant difference in all sagittal parameters and visual analogue scale (VAS) score between these 2 groups. Correlation analysis revealed significant relationships between sagittal parameters in AS. However, there was no association between sacral slope and S1 overhang, and between pelvic incidence and VAS score. Stepwise logistic regression analysis revealed that pelvic tilt contributed significantly to sagittal balance. AS patients and normal controls were found to be significantly different in terms of sagittal spinopelvic parameters. Significant relationships were found between sagittal spinopelvic parameters in AS patients. Pelvic tilt was a significant parameter in determination of sagittal balance in AS patient. Furthermore, VAS scores were

  15. Isolation, crystallization and preliminary crystallographic analysis of Salmonella typhimurium uridine phosphorylase crystallized with 2,2′-anhydrouridine

    Science.gov (United States)

    Timofeev, Vladimir I.; Lashkov, Alexander A.; Gabdoulkhakov, Azat G.; Pavlyuk, Bogdan Ph.; Kachalova, Galina S.; Betzel, Christian; Morgunova, Ekaterina Yu.; Zhukhlistova, Nadezhda E.; Mikhailov, Al’bert M.

    2007-01-01

    Uridine phosphorylase (UPh; EC 2.4.2.3) is a member of the pyrimidine nucleoside phosphorylase family of enzymes which catalyzes the phosphorolytic cleavage of the C—N glycoside bond of uridine, with the formation of ribose 1-­phosphate and uracil. This enzyme has been shown to be important in the activation and catabolism of fluoropyrimidines. Modulation of its enzymatic activity may affect the therapeutic efficacy of chemotherapeutic agents. The structural investigation of the bacterial uridine phosphorylases, both unliganded and complexed with substrate/product analogues and inhibitors, may help in understanding the catalytic mechanism of the phosphorolytic cleavage of uridine. Salmonella typhimurium uridine phosphorylase has been crystallized with 2,2′-anhydrouridine. X-ray diffraction data were collected to 2.15 Å. Preliminary analysis of the diffraction data indicates that the crystal belongs to space group P212121, with unit-cell parameters a = 88.52, b = 123.98, c = 133.52 Å. The solvent content is 45.51%, assuming the presence of one hexamer molecule per asymmetric unit. PMID:17909287

  16. Isolation, crystallization and preliminary crystallographic analysis of Salmonella typhimurium uridine phosphorylase crystallized with 2,2'-anhydrouridine.

    Science.gov (United States)

    Timofeev, Vladimir I; Lashkov, Alexander A; Gabdoulkhakov, Azat G; Pavlyuk, Bogdan Ph; Kachalova, Galina S; Betzel, Christian; Morgunova, Ekaterina Yu; Zhukhlistova, Nadezhda E; Mikhailov, Al'bert M

    2007-10-01

    Uridine phosphorylase (UPh; EC 2.4.2.3) is a member of the pyrimidine nucleoside phosphorylase family of enzymes which catalyzes the phosphorolytic cleavage of the C-N glycoside bond of uridine, with the formation of ribose 1-phosphate and uracil. This enzyme has been shown to be important in the activation and catabolism of fluoropyrimidines. Modulation of its enzymatic activity may affect the therapeutic efficacy of chemotherapeutic agents. The structural investigation of the bacterial uridine phosphorylases, both unliganded and complexed with substrate/product analogues and inhibitors, may help in understanding the catalytic mechanism of the phosphorolytic cleavage of uridine. Salmonella typhimurium uridine phosphorylase has been crystallized with 2,2'-anhydrouridine. X-ray diffraction data were collected to 2.15 A. Preliminary analysis of the diffraction data indicates that the crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 88.52, b = 123.98, c = 133.52 A. The solvent content is 45.51%, assuming the presence of one hexamer molecule per asymmetric unit.

  17. Analysis of Nematic Liquid Crystals with Disclination Lines

    CERN Document Server

    Bauman, P; Phillips, D

    2011-01-01

    We investigate the structure of nematic liquid crystal thin films described by the Landau--de Gennes tensor-valued order parameter with Dirichlet boundary conditions of nonzero degree. We prove that as the elasticity constant goes to zero a limiting uniaxial texture forms with disclination lines corresponding to a finite number of defects, all of degree 1/2 or all of degree -1/2. We also state a result on the limiting behavior of minimizers of the Chern-Simons-Higgs model without magnetic field that follows from a similar proof.

  18. The analysis of crystallization of sodium chloride from the solution in vacuum crystallizer with the recirculation of the suspension

    Directory of Open Access Journals (Sweden)

    Jotanović Milovan B.

    2009-01-01

    Full Text Available Crystallization from a solution most often is the final stage of many technological processes, and has a major role in bulk chemical industry. Basic requirements which stand before the process of crystallization are as follows: providing a minimum energy use-up together with a maximum specific capacity of the crystallizer, as well as with obtaining a product with the necessary degree of purity. These demands are successfully fulfilled by vacuum crystallizers with recirculation of suspension, which are the most promising apparatus for the crystallization of inorganic salts from solutions in bulk production. Vacuum crystallizers, like other chemical apparatuses, are described as a sum of physical and chemical phenomena which together create a unit process of crystallization of NaCl from water solutions. The term apparatus process unit (APU was introduced and a vacuum crystallizer is described as the sum of APU and shown in a structural scheme. The analysis of the vacuum crystallizer was performed based on its APU component, using theoretical assumptions, the results published as well as the results of researches on models. A particular focus was given to the description of the mass and heat transfer, as well as to the hydrodynamics of fluids in the area where the starting solution and the recircular suspension are mixed, in the circulation channel and the central pipe, as well as in the area of vaporization. This study gives the conclusions made based on the investigation of vacuum crystallizers. .

  19. Crystallization and preliminary X-ray diffraction analysis of L-threonine dehydrogenase (TDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis.

    Science.gov (United States)

    Bowyer, A; Mikolajek, H; Wright, J N; Coker, A; Erskine, P T; Cooper, J B; Bashir, Q; Rashid, N; Jamil, F; Akhtar, M

    2008-09-01

    The enzyme L-threonine dehydrogenase catalyses the NAD(+)-dependent conversion of L-threonine to 2-amino-3-ketobutyrate, which is the first reaction of a two-step biochemical pathway involved in the metabolism of threonine to glycine. Here, the crystallization and preliminary crystallographic analysis of L-threonine dehydrogenase (Tk-TDH) from the hyperthermophilic organism Thermococcus kodakaraensis KOD1 is reported. This threonine dehydrogenase consists of 350 amino acids, with a molecular weight of 38 kDa, and was prepared using an Escherichia coli expression system. The purified native protein was crystallized using the hanging-drop vapour-diffusion method and crystals grew in the tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 124.5, c = 271.1 A. Diffraction data were collected to 2.6 A resolution and preliminary analysis indicates that there are four molecules in the asymmetric unit of the crystal.

  20. Strain Analysis of Stretched Tourmaline Crystals Using ImageJ, Microsoft Excel and PowerPoint

    Science.gov (United States)

    Bosbyshell, H.

    2012-12-01

    This poster describes an undergraduate structural geology lab exercise utilizing the Mohr's circle diagram for finite strain, constructed using measurements obtained from stretched tourmaline crystals. A small building housing HVAC equipment at the south end of West Chester University's Recitation Hall (itself made of serpentinite) is constructed of early-Cambrian Chickies Quartzite. Stretched tourmaline crystals, with segments joined by fibrous quartz, are visible on many surfaces (presumably originally bedding). While the original orientation of any stone is unknown, these rocks provide an opportunity for a short field exercise during a two-hour lab period and a great base for conducting strain analysis. It is always fun to ask how many in the class have ever noticed the tourmaline (few have). Students take photos using their cell phones or cameras. Since strain is a ratio the absolute size of the tourmaline crystals is immaterial. Nonetheless, this is a good opportunity to remind students of the importance of including a scale in their photographs. The photos are opened in ImageJ and the line tool is used to determine the original and final lengths of selected crystals. Students calculate strain parameters using Microsoft Excel. Then, we use Adobe Illustrator or the drafting capabilities of Microsoft PowerPoint 2010 to follow Ramsay and Huber's techniques using a Mohr's circle construction to determine the finite strain ellipse. If a stretching direction can be estimated, elongation of two crystals is all that is required to determine the strain ratio. If no stretching direction is apparent, three crystals are required for a more complicated analysis that allows for determination of the stretching direction, as well as the strain ratio.

  1. Overexpression, purification, crystallization and preliminary X-ray analysis of Rv2780 from Mycobacterium tuberculosis H37Rv

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Sarvind Mani; Ramachandran, Ravishankar, E-mail: r-ravishankar@cdri.res.in [Molecular and Structural Biology Division, Central Drug Research Institute, PO Box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow 226001 (India)

    2008-05-01

    Rv2780, an alanine dehydrogenase from M. tuberculosis, has been crystallized in apo and NAD/pyruvate-bound forms. Preliminary crystallographic analysis shows that there is a hexamer and trimer in the asymmetric units of the apo and ternary complex forms, respectively. Rv2780, an alanine dehydrogenase from Mycobacterium tuberculosis (MtAlaDH), catalyzes the NAD-dependent interconversion of alanine and pyruvate. Alanine dehydrogenase is released into the culture medium in substantial amounts by virulent strains of mycobacteria and is not found in the vaccine strain of tuberculosis. Crystals of recombinant MtAlaDH were grown from 2 M ammonium sulfate solution at ∼12 mg ml{sup −1} protein concentration in two crystal forms which occur in the presence and absence of NAD/pyruvate, respectively. Diffraction data extending to 2.6 Å were collected at room temperature from both apo and ternary complex crystals. Crystals of the apoenzyme have unit-cell parameters a = 173.89, b = 127.07, c = 135.95 Å. They are rod-like in shape and belong to space group C2. They contain a hexamer in the asymmetric unit. Crystals of the ternary complex belong to space group P4{sub 3}2{sub 1}2 and have unit-cell parameters a = b = 88.99, c = 373.85 Å. There are three subunits in the asymmetric unit of the holoenzyme crystals.

  2. Crystallization and preliminary X-ray diffraction analysis of human adenovirus

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, V.S.; Natchiar, S.K.; Gritton, L.; Mullen, T.-M.; Stewart, P.L.; Nemerow, G.R. (Scripps); (Vanderbilt)

    2010-07-22

    Replication-defective and conditionally replicating adenovirus (AdV) vectors are currently being utilized in {approx}25% of human gene transfer clinical trials. Unfortunately, progress in vector development has been hindered by a lack of accurate structural information. Here we describe the crystallization and preliminary X-ray diffraction analysis of a HAdV5 vector that displays a short flexible fiber derived from HAdV35. Crystals of Ad35F were grown in 100 mM HEPES pH 7.0, 200 mM Ca(OAc){sub 2}, 14% PEG 550 MME, 15% glycerol in 100 mM Tris-HCl 8.5. Freshly grown crystals diffracted well to 4.5 {angstrom} resolution and weakly to 3.5 {angstrom} at synchrotron sources. HAdV crystals belong to space group P1 with unit cell parameters a = 854.03 {angstrom}, b = 855.17 {angstrom}, c = 865.24 {angstrom}, {alpha} = 119.57{sup o}, {beta} = 91.71{sup o}, {gamma} = 118.08{sup o} with a single particle in the unit cell. Self-rotation and locked-rotation function analysis allowed the determination of the particle orientation. Molecular replacement, density modification and phase-extension procedures are being employed for structure determination.

  3. Reinforcement Learning for Ramp Control: An Analysis of Learning Parameters

    Directory of Open Access Journals (Sweden)

    Chao Lu

    2016-08-01

    Full Text Available Reinforcement Learning (RL has been proposed to deal with ramp control problems under dynamic traffic conditions; however, there is a lack of sufficient research on the behaviour and impacts of different learning parameters. This paper describes a ramp control agent based on the RL mechanism and thoroughly analyzed the influence of three learning parameters; namely, learning rate, discount rate and action selection parameter on the algorithm performance. Two indices for the learning speed and convergence stability were used to measure the algorithm performance, based on which a series of simulation-based experiments were designed and conducted by using a macroscopic traffic flow model. Simulation results showed that, compared with the discount rate, the learning rate and action selection parameter made more remarkable impacts on the algorithm performance. Based on the analysis, some suggestionsabout how to select suitable parameter values that can achieve a superior performance were provided.

  4. Measurement of the Slope Parameter $\\alpha$ for the $\\eta\\to 3\\pi^0$ decay with the Crystal Ball at MAMI-C

    CERN Document Server

    Prakhov, S; Aguar, P; Akasoy, L K; Annand, J R M; Arends, H J; Bartolome, P A; Bantawa, K; Beck, R; Bekrenev, V; Berghauser, H; Boillat, B; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Downie, E J; Drexler, P; Filkov, L V; Glazier, D I; Gregor, R; Heid, E; Hornidge, D; Jahn, O; Jude, T C; Kashevarov, V L; Kellie, J D; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Krambrich, D; Kruglov, S; Krusche, B; Lang, M; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Manley, D M; Martínez, M; McGeorge, J C; McNicoll, E F; Mekterovic, D; Metag, V; Micanovic, S; Nikolaev, A; Novotny, R; Ostrick, M; Otte, P B; Pedroni, P; Pheron, F; Polonski, A; Robinson, J; Rosner, G; Rost, M; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D I; Starostin, A; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Zamboni, I; Zehr, F

    2008-01-01

    The dynamics of the $\\eta\\to 3\\pi^0$ decay have been studied with the Crystal Ball multiphoton spectrometer and the TAPS calorimeter. Bremsstrahlung photons produced by the 1.5 GeV electron beam of the Mainz microtron MAMI-C and tagged by the Glasgow photon spectrometer were used for $\\eta$-meson production. The analysis of $3 \\times 10^6$ $\\gamma p \\to \\eta p \\to 3\\pi^0 p \\to 6\\gamma p$ events yields the value $\\alpha=-0.032\\pm0.003$ for the $\\eta\\to 3\\pi^0$ slope parameter, which agrees with the majority of recent experimental results and has the smallest uncertainty. The $\\pi^0\\pi^0$ invariant-mass spectrum was investigated for the occurrence of a cusp-like structure in the vicinity of the $\\pi^+\\pi^-$ threshold. The observed effect is small and does not affect our measured value for the slope parameter.

  5. Correlation Analysis between TCM Syndromes and Physicochemical Parameters

    Institute of Scientific and Technical Information of China (English)

    SUN Zhan-quan; XI Guang-cheng; Li Hai-xia; YI Jian-qiang; WANG jie

    2006-01-01

    Traditionally, differentiation of syndromes of Traditional Chinese Medicine (TCM) mainly depends on the information obtained from four diagnosis methods. Now many physicochemical parameters are available in clinic. There exists great correlation between TCM syndromes and physicochemical parameters.The objective of the paper is to analyze the correlation between TCM syndromes and physicochemical parameters quantitatively. Correlation analysis has been widely studied and many analysis methods have been developed. Mutual information based on entropy can measure arbitrary dependence between variables. It has been applied to many kinds of fields, especially to pattern recognition. But most works are restricted to discrete variables and little work has been done to study the relation between discrete and continuous variables. A novel algorithm is proposed to calculate the mutual information between discrete and continuous variables. It is used to analyze the correlation between TCM syndromes and physicochemical parameters.

  6. Facile synthesis, single crystal analysis, and computational studies of sulfanilamide derivatives

    Science.gov (United States)

    Tahir, Muhammad Nawaz; Khalid, Muhammad; Islam, Ayesha; Ali Mashhadi, Syed Muddassir; Braga, Ataualpa A. C.

    2017-01-01

    Antibacterial resistance is a worldwide problem. Sulfanilamide is widely used antibacterial. For the first time, we report here a simple method for the derivative synthesis of the title drugs, single crystal XRD and density functional theory (DFT) studies. The optimized molecular structure, natural bond orbital (NBO), frontier molecular orbitals (FMOs) molecular electrostatic potential studies (MEP) and Mulliken population analysis (MPA) have been performed using M06-2X/6-31G(d, p). The FT-IR spectra and thermodynamic parameters were calculated at M06-2X/6-311 + G(2d,p) and B3LYP/6-31G(d, p) levels respectively, while, the UV-Vis analysis was performed using TD-DFT/B3LYP/6-31G(d, p) method. The experimental FT-IR spectra of both compounds were also carried out to reconfirm sbnd H⋯Osbnd hydrogen bonds. The DFT optimized parameters exhibiting good agreement with the experimental data. NBO analysis explored the hyper conjugative interaction and stability of title crystals, especially, reconfirmed the existence of sbnd H⋯Osbnd hydrogen bonds between the dimers. The FT-IR, thermodynamic parameters, MEP and MPA also revealed the hydrogen bonding detail is harmonious to XRD data. As a matter of the fact, the hydrogen bonding is a significant parameter for the understanding and design of molecular crystals, subsequently; it can also play a vital role in the supramolecular chemistry. Moreover, the global reactivity descriptors suggest that title compounds might be bioactive.

  7. Bloch-mode analysis for retrieving effective parameters of metamaterials

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Ha, Sangwoo; Sukhorukov, Andrey A.

    2012-01-01

    We introduce an approach for retrieving effective parameters of metamaterials based on the Bloch-mode analysis of quasiperiodic composite structures. We demonstrate that, in the case of single-mode propagation, a complex effective refractive index can be assigned to the structure, being restored...... that this approach can be useful for retrieval of both material and wave effective parameters of a broad range of metamaterials....

  8. Stability Analysis for Multi-Parameter Linear Periodic Systems

    DEFF Research Database (Denmark)

    Seyranian, A.P.; Solem, Frederik; Pedersen, Pauli

    1999-01-01

    This paper is devoted to stability analysis of general linear periodic systems depending on real parameters. The Floquet method and perturbation technique are the basis of the development. We start out with the first and higher-order derivatives of the Floquet matrix with respect to problem...... parameters. Then the behaviour of simple and multiple multipliers of the system with a change of parameters is studied. Weak and strong interactions of multipliers in the complex plane are treated separately. The presented theory is exemplified and discussed....

  9. Frequency and Temperature Dependence of Fabrication Parameters in Polymer Dispersed Liquid Crystal Devices

    Directory of Open Access Journals (Sweden)

    Juan C. Torres

    2014-05-01

    Full Text Available A series of polymer dispersed liquid crystal devices using glass substrates have been fabricated and investigated focusing on their electrical properties. The devices have been studied in terms of impedance as a function of frequency. An electric equivalent circuit has been proposed, including the influence of the temperature on the elements into it. In addition, a relevant effect of temperature on electrical measurements has been observed.

  10. Primary component analysis method and reduction of seismicity parameters

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; MA Qin-zhong; LIN Ming-zhou; WU Geng-feng; WU Shao-chun

    2005-01-01

    In the paper, the primary component analysis is made using 8 seismicity parameters of earthquake frequency N (ML≥3.0), b-value, 7-value, A(b)-value, Mf-value, Ac-value, C-value and D-value that reflect the characteristics of magnitude, time and space distribution of seismicity from different respects. By using the primary component analysis method, the synthesis parameter W reflecting the anomalous features of earthquake magnitude, time and space distribution can be gained. Generally, there is some relativity among the 8 parameters, but their variations are different in different periods. The earthquake prediction based on these parameters is not very well. However,the synthesis parameter W showed obvious anomalies before 13 earthquakes (MS>5.8) occurred in North China,which indicates that the synthesis parameter W can reflect the anomalous characteristics of magnitude, time and space distribution of seismicity better. Other problems related to the conclusions drawn by the primary component analysis method are also discussed.

  11. Influence analysis of structural parameters and operating parameters on electromagnetic properties of HTS linear induction motor

    Science.gov (United States)

    Fang, J.; Sheng, L.; Li, D.; Zhao, J.; Li, Sh.; Qin, W.; Fan, Y.; Zheng, Q. L.; Zhang, W.

    A novel High Temperature Superconductor Linear Induction Motor (HTS LIM) is researched in this paper. Since the critical current and the electromagnetic force of the motor are determined mainly by the primary slot leakage flux, the main magnetic flux and eddy current respectively, in order to research the influence of structural parameters and operating parameters on electromagnetic properties of HTS LIM, the motor was analyzed by 2D transient Finite Element Method (FEM). The properties of the motor, such as the maximum slot leakage flux density, motor thrust, motor vertical force and critical current are analyzed with different structural parameters and operating parameters. In addition, an experimental investigation was carried out on prototype HTS motor. Electrical parameters were deduced from these tests and also compared with the analysis results from FEM. AC losses of one HTS coil in the motor were measured and AC losses of all HTS coils in HTS LIM were estimated. The results in this paper could provide reference for the design and research on the HTS LIM.

  12. Numerical Simulation of Dendritic crystal growth using phase field method and investigating the effects of different physical parameter on the growth of the dendrite

    OpenAIRE

    Sanal, Rahul

    2014-01-01

    In this journal, we study the phase-field model of solidification for numerical simulation of dendritic crystal growth that occurs during the casting of metals and alloys based on the kobayashi [1] model. Qualitative relationships between shapes of the crystal and physical parameters are studied and visualized.

  13. Impact on the Spatial Resolution Performance of a Monolithic Crystal PET Detector Due to Different Sensor Parameters.

    Science.gov (United States)

    Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K; Miyaoka, Robert S

    2009-10-24

    The performance characteristics of a monolithic crystal PET detector utilizing a novel sensor on the entrance surface (SES) design is reported. To facilitate this design, we propose to utilize a 2D silicon photomultiplier (SiPM) array device. SiPMs are a form of Geiger-Muller mode avalanche photodiodes (GMAPD) that can provide signal gain similar to a photomultiplier tube (PMT). Since these devices are still under active development, their performance parameters are changing. Using a multi-step simulation process, we investigated how different SiPM parameters affect the performance of a monolithic crystal PET detector. These parameters include gain variability between different channels; gain instability; and dark count noise. The detector simulated was a 49.6 mm by 49.6 mm by 15 mm LYSO crystal detector readout by a 16 by 16 array of 2.8 mm by 2.8 mm SiPM elements. To reduce the number of signal channels that need to be collected, the detector utilizes row-column summing. A statistics based positioning method is used for event positioning and depth of interaction (DOI) decoding. Of the variables investigated, the dark count noise had the largest impact on the intrinsic spatial resolution. Gain differences of 5-10% between detector calibration and detector testing had a modest impact on the intrinsic spatial resolution performance and led to a slight bias in positioning. There was no measurable difference with a gain variability of up to 25% between the individual SiPM channels. Based upon these results we are planning to cool our detectors below room temperature to reduce dark count noise and to actively control the temperature of the SiPMs to reduce drifts in gain over time.

  14. Desiccator Volume: A Vital Yet Ignored Parameter in CaCO3 Crystallization by the Ammonium Carbonate Diffusion Method

    Directory of Open Access Journals (Sweden)

    Joe Harris

    2017-07-01

    Full Text Available Employing the widely used ammonium carbonate diffusion method, we demonstrate that altering an extrinsic parameter—desiccator size—which is rarely detailed in publications, can alter the route of crystallization. Hexagonally packed assemblies of spherical magnesium-calcium carbonate particles or spherulitic aragonitic particles can be selectively prepared from the same initial reaction solution by simply changing the internal volume of the desiccator, thereby changing the rate of carbonate addition and consequently precursor formation. This demonstrates that it is not merely the quantity of an additive which can control particle morphogenesis and phase selectivity, but control of other often ignored parameters are vital to ensure adequate reproducibility.

  15. Privacy Preserving Categorical Data Analysis with Unknown Distortion Parameters

    Directory of Open Access Journals (Sweden)

    Ling Guo

    2009-12-01

    Full Text Available Randomized Response techniques have been investigated in privacy preserving categorical data analysis. However, the released distortion parameters can be exploited by attackers to breach privacy. In this paper, we investigate whether data mining or statistical analysis tasks can still be conducted on randomized data when distortion parameters are not disclosed to data miners. We first examine how various objective association measures between two variables may be affected by randomization. We then extend to multiple variables by examining the feasibility of hierarchical loglinear modeling. Finally we show some classic data mining tasks that cannot be applied on the randomized data directly.

  16. Analysis of Boundary Conditions for Crystal Defect Atomistic Simulations

    Science.gov (United States)

    Ehrlacher, V.; Ortner, C.; Shapeev, A. V.

    2016-12-01

    Numerical simulations of crystal defects are necessarily restricted to finite computational domains, supplying artificial boundary conditions that emulate the effect of embedding the defect in an effectively infinite crystalline environment. This work develops a rigorous framework within which the accuracy of different types of boundary conditions can be precisely assessed. We formulate the equilibration of crystal defects as variational problems in a discrete energy space and establish qualitatively sharp regularity estimates for minimisers. Using this foundation we then present rigorous error estimates for (i) a truncation method (Dirichlet boundary conditions), (ii) periodic boundary conditions, (iii) boundary conditions from linear elasticity, and (iv) boundary conditions from nonlinear elasticity. Numerical results confirm the sharpness of the analysis.

  17. Purification, crystallization and preliminary structural analysis of nucleoside diphosphate kinase from Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Gauri [Molecular and Structural Biology Division, Central Drug Research Institute, PO Box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow 226 001 (India); Aggarwal, Anita [Institute of Genomics and Integrative Biology, Mall Road, Delhi 110 007 (India); Mittal, Sonia [Molecular and Structural Biology Division, Central Drug Research Institute, PO Box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow 226 001 (India); Singh, Yogendra [Institute of Genomics and Integrative Biology, Mall Road, Delhi 110 007 (India); Ramachandran, Ravishankar, E-mail: r-ravishankar@cdri.res.in [Molecular and Structural Biology Division, Central Drug Research Institute, PO Box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow 226 001 (India)

    2007-12-01

    Nucleoside diphosphate kinase from B. anthracis has been crystallized. Preliminary crystallographic analysis shows that there is one monomer in the asymmetric unit of the crystal. Bacillus anthracis nucleoside diphosphate kinase (BaNdk) is an enzyme whose primary function is to maintain deoxynucleotide triphosphate (dNTP) pools by converting deoxynucleotide diphosphates to triphosphates using ATP as the major phosphate donor. Although the structures of Ndks from a variety of organisms have been elucidated, the enzyme from sporulating bacteria has not been structurally characterized to date. Crystals of the B. anthracis enzyme were grown using the vapour-diffusion method from a hanging drop consisting of 2 µl 10 mg ml{sup −1} protein in 50 mM Tris–HCl pH 8.0, 50 mM NaCl, 5 mM EDTA equilibrated against 500 µl reservoir solution consisting of 2.25 M ammonium formate and 0.1 M HEPES buffer pH 7.25. Diffraction data extending to 2.0 Å were collected at room temperature from a single crystal with unit-cell parameters a = b = 107.53, c = 52.3 Å. The crystals are hexagonal in shape and belong to space group P6{sub 3}22. The crystals contain a monomer in the asymmetric unit, which corresponds to a Matthews coefficient (V{sub M}) of 2.1 Å{sup 3} Da{sup −1} and a solvent content of about 36.9%.

  18. Crystal-Chemical Analysis Martian Minerals in Gale Crater

    Science.gov (United States)

    Morrison, S. M.; Downs, R. T.; Blake, D. F.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Yen, A. S.; Chipera, S. J.; Treiman, A. H.; Vaniman, D. T.; hide

    2015-01-01

    The CheMin instrument on the Mars Science Laboratory rover Curiosity performed X-ray diffraction analyses on scooped soil at Rocknest and on drilled rock fines at Yellowknife Bay (John Klein and Cumberland samples), The Kimberley (Windjana sample), and Pahrump (Confidence Hills sample) in Gale crater, Mars. Samples were analyzed with the Rietveld method to determine the unit-cell parameters and abundance of each observed crystalline phase. Unit-cell parameters were used to estimate compositions of the major crystalline phases using crystal-chemical techniques. These phases include olivine, plagioclase and clinopyroxene minerals. Comparison of the CheMin sample unit-cell parameters with those in the literature provides an estimate of the chemical compositions of the major crystalline phases. Preliminary unit-cell parameters, abundances and compositions of crystalline phases found in Rocknest and Yellowknife Bay samples were reported in. Further instrument calibration, development of 2D-to- 1D pattern conversion corrections, and refinement of corrected data allows presentation of improved compositions for the above samples.

  19. Reference priors of nuisance parameters in Bayesian sequential population analysis

    CERN Document Server

    Bousquet, Nicolas

    2010-01-01

    Prior distributions elicited for modelling the natural fluctuations or the uncertainty on parameters of Bayesian fishery population models, can be chosen among a vast range of statistical laws. Since the statistical framework is defined by observational processes, observational parameters enter into the estimation and must be considered random, similarly to parameters or states of interest like population levels or real catches. The former are thus perceived as nuisance parameters whose values are intrinsically linked to the considered experiment, which also require noninformative priors. In fishery research Jeffreys methodology has been presented by Millar (2002) as a practical way to elicit such priors. However they can present wrong properties in multiparameter contexts. Therefore we suggest to use the elicitation method proposed by Berger and Bernardo to avoid paradoxical results raised by Jeffreys priors. These benchmark priors are derived here in the framework of sequential population analysis.

  20. Sensitivity Analysis of Hardwired Parameters in GALE Codes

    Energy Technology Data Exchange (ETDEWEB)

    Geelhood, Kenneth J.; Mitchell, Mark R.; Droppo, James G.

    2008-12-01

    The U.S. Nuclear Regulatory Commission asked Pacific Northwest National Laboratory to provide a data-gathering plan for updating the hardwired data tables and parameters of the Gaseous and Liquid Effluents (GALE) codes to reflect current nuclear reactor performance. This would enable the GALE codes to make more accurate predictions about the normal radioactive release source term applicable to currently operating reactors and to the cohort of reactors planned for construction in the next few years. A sensitivity analysis was conducted to define the importance of hardwired parameters in terms of each parameter’s effect on the emission rate of the nuclides that are most important in computing potential exposures. The results of this study were used to compile a list of parameters that should be updated based on the sensitivity of these parameters to outputs of interest.

  1. Tilt order parameters, polarity, and inversion phenomena in smectic liquid crystals.

    Science.gov (United States)

    Karahaliou, P K; Vanakaras, A G; Photinos, D J

    2002-03-01

    The order parameters for the phenomenological description of the smectic-A to smectic-C phase transition are formulated on the basis of molecular symmetry and structure. It is shown that, unless the long molecular axis is an axis of twofold or higher rotational symmetry, the ordering of the molecules in the smectic-C phase gives rise to more than one tilt order parameter and to one or more polar order parameters. The latter describe the indigenous polarity of the smectic-C phase, which is not related to molecular chirality but underlies the appearance of spontaneous polarization in chiral smectics. A phenomenological theory of the phase transition is formulated by means of a Landau expansion in two tilt order parameters (primary and secondary) and an indigenous polarity order parameter. The coupling among these order parameters determines the possibility of sign inversions in the temperature dependence of the spontaneous polarization and of the helical pitch observed experimentally for some chiral smectic-C* materials. The molecular interpretation of the inversion phenomena is examined in the light of this formulation.

  2. Optimization of plasma parameters for the production of silicon nano-crystals

    CERN Document Server

    Chaabane, N; Vach, H; Cabarrocas, P R I

    2003-01-01

    We use silane-hydrogen plasmas to synthesize silicon nano-crystals in the gas phase and thermophoresis to collect them onto a cooled substrate. To distinguish between nano-crystals formed in the plasma and those grown on the substrate, as a result of surface and subsurface reactions, we have simultaneously deposited films on a conventional substrate heated at 250 deg. C and on a second substrate cooled down to 90 deg. C. A series of samples deposited at various discharge pressures, in the range of 400 mTorr to 1.2 Torr, have been characterized by Raman spectroscopy and ellipsometry. At low pressure (400-500 mTorr), the films are amorphous on the cold substrate and micro-crystalline on the hot one. As pressure increases, gas phase reactions lead to the formation of nano-crystalline particles which are attracted by the cold substrate due to thermophoresis. Consequently, we obtain nano-crystalline silicon thin films on the cold substrate and amorphous thin films on the heated one in the pressure range of 600-900...

  3. Crystallization and preliminary X-ray analysis of Chandipura virus glycoprotein G.

    Science.gov (United States)

    Baquero, Eduard; Buonocore, Linda; Rose, John K; Bressanelli, Stéphane; Gaudin, Yves; Albertini, Aurélie A

    2012-09-01

    Fusion in members of the Rhabdoviridae virus family is mediated by the G glycoprotein. At low pH, the G glycoprotein catalyzes fusion between viral and endosomal membranes by undergoing a major conformational change from a pre-fusion trimer to a post-fusion trimer. The structure of the G glycoprotein from vesicular stomatitis virus (VSV G), the prototype of Vesiculovirus, has recently been solved in its trimeric pre-fusion and post-fusion conformations; however, little is known about the structural details of the transition. In this work, a soluble form of the ectodomain of Chandipura virus G glycoprotein (CHAV G(th)) was purified using limited proteolysis of purified virus; this soluble ectodomain was also crystallized. This protein shares 41% amino-acid identity with VSV G and thus its structure could provide further clues about the structural transition of rhabdoviral glycoproteins induced by low pH. Crystals of CHAV G(th) obtained at pH 7.5 diffracted X-rays to 3.1 Å resolution. These crystals belonged to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 150.3, b = 228.2, c = 78.8 Å. Preliminary analysis of the data based on the space group and the self-rotation function indicated that there was no trimeric association of the protomers. This unusual oligomeric status could result from the presence of fusion intermediates in the crystal.

  4. Cloning, expression, crystallization and preliminary X-ray data analysis of norcoclaurine synthase from Thalictrum flavum

    Energy Technology Data Exchange (ETDEWEB)

    Pasquo, Alessandra [ENEA Casaccia Research Centre, Dipartimento BIOTEC, Sezione Genetica e Genomica Vegetale, PO Box 2400, I-00100 Rome (Italy); Bonamore, Alessandra; Franceschini, Stefano; Macone, Alberto; Boffi, Alberto; Ilari, Andrea, E-mail: andrea.ilari@uniroma1.it [Istituto di Biologia e Patologia Molecolari, CNR (IBPM) and Department Of Biochemical Sciences, University of Roma ‘La Sapienza’, Piazza Aldo Moro 5, 00179 Roma (Italy); ENEA Casaccia Research Centre, Dipartimento BIOTEC, Sezione Genetica e Genomica Vegetale, PO Box 2400, I-00100 Rome (Italy)

    2008-04-01

    The cloning, expression, crystallization and preliminary X-ray data analysis of norcoclaurine synthase from T. flavum, a protein which catalyzes the first committed step in the biosynthesis of benzylisoquinoline alkaloids, are reported. Norcoclaurine synthase (NCS) catalyzes the condensation of 3,4-dihydroxyphenylethylamine (dopamine) and 4-hydroxyphenylacetaldehyde (4-HPAA) as the first committed step in the biosynthesis of benzylisoquinoline alkaloids in plants. The protein was cloned, expressed and purified. Crystals were obtained at 294 K by the hanging-drop vapour-diffusion method using ammonium sulfate and sodium chloride as precipitant agents and diffract to better than 3.0 Å resolution using a synchrotron-radiation source. The crystals belong to the trigonal space group P3{sub 1}21, with unit-cell parameters a = b = 86.31, c = 118.36 Å. A selenomethionine derivative was overexpressed, purified and crystallized in the same space group. A complete MAD data set was collected at 2.7 Å resolution. The model is under construction.

  5. Crystallization and preliminary X-ray analysis of alginate importer from Sphingomonas sp. A1.

    Science.gov (United States)

    Maruyama, Yukie; Itoh, Takafumi; Nishitani, Yu; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2012-03-01

    Sphingomonas sp. A1 directly incorporates alginate polysaccharides through a 'superchannel' comprising a pit on the cell surface, alginate-binding proteins in the periplasm and an ABC transporter (alginate importer) in the inner membrane. Alginate importer, consisting of four subunits, AlgM1, AlgM2 and two molecules of AlgS, was crystallized in the presence of the binding protein AlgQ2. Preliminary X-ray analysis showed that the crystal diffracted to 3.3 Å resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 72.5, b = 136.8, c = 273.3 Å, suggesting the presence of one complex in the asymmetric unit.

  6. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Offsite consequence analysis parameters. 68.22 Section 68.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... topography, as appropriate. Urban means that there are many obstacles in the immediate area; obstacles...

  7. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry; Optimisation des parametres de scintillation des cristaux de tungstate de plomb pour leur application dans la calorimetrie electromagnetique de haute precision

    Energy Technology Data Exchange (ETDEWEB)

    Drobychev, G

    2000-04-12

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals (PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  8. Characterization of calcium lactate crystals on cheddar cheese by image analysis.

    Science.gov (United States)

    Rajbhandari, P; Kindstedt, P S

    2008-06-01

    Previous research demonstrated that crystal coverage on the surface of Cheddar cheese can be quantitatively and nondestructively measured using image analysis of digital photographs of the cheese surface. The objective of the present study was to extend image analysis methodology to quantify and characterize additional features of visible crystals on cheese surfaces as they grow over time. A random weight (approximately 300 g) retail sample of naturally smoked Cheddar cheese exhibiting white surface crystals was obtained from a commercial source. The total area occupied by crystals and total number of discrete crystal regions on one of the surfaces (approximately 55 x 120 mm) was measured at 3-wk intervals for 30 wk using image analysis. In addition, 5 small (approximately 0.3 mm radius) individual crystals on that surface were chosen for observation over the 30-wk period. The crystals were evaluated for area, radius, and shape factor (circularity) every third week using image analysis. The total area occupied by crystals increased in a linear manner (R(2) = 0.95) from about 0.44 to 7.42% of the total cheese surface area over the 30-wk period. The total number of discrete crystal regions also increased but in a nonlinear manner that was best described by a quadratic relationship. Measurement of discrete crystal regions underestimated the true number of crystals present at the cheese surface due to merging of adjacent crystals as they grew and merged into a single crystal region over time. Throughout this period, the shapes of the 5 individual crystals closely approximated perfect circles, except when adjacent crystals merged to form a single irregular crystal region, and the area occupied by each of the 5 crystals increased in a near-linear manner (R(2) = 0.95). Image analysis approaches may be used to evaluate crystal formation and growth rates and morphology on cheese.

  9. Purification, crystallization and preliminary X-ray crystallographic analysis of rice bifunctional α-amylase/subtilisin inhibitor from Oryza sativa

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Hung [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Peng, Wen-Yan [Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Huang, Yen-Chieh [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Guan, Hong-Hsiang; Hsieh, Ying-Cheng [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Chang, Tschining [Department of Hospitality Management, Nan Jeon Institute of Technology, Yen-Shui, Tainan 73746,Taiwan (China); Chen, Chun-Jung, E-mail: cjchen@nsrrc.org.tw [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China)

    2006-08-01

    The crystallization of rice α-amylase/subtilisin bifunctional inhibitor is reported. Rice bifunctional α-amylase/subtilisin inhibitor (RASI) can inhibit both α-amylase from larvae of the red flour beetle (Tribolium castaneum) and subtilisin from Bacillus subtilis. The synthesis of RASI is up-regulated during the late milky stage in developing seeds. The 8.9 kDa molecular-weight RASI from rice has been crystallized using the hanging-drop vapour-diffusion method. According to 1.81 Å resolution X-ray diffraction data from rice RASI crystals, the crystal belongs to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 79.99, b = 62.95, c = 66.70 Å. Preliminary analysis indicates two RASI molecules in an asymmetric unit with a solvent content of 44%.

  10. Purification, crystallization and preliminary X-ray crystallographic analysis of branched-chain aminotransferase from Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chung-Der; Huang, Tien-Feng [Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Lin, Chih-Hao [Institute of Biological Chemistry, National Taiwan University, Taipei 110,Taiwan (China); Guan, Hong-Hsiang; Hsieh, Yin-Cheng [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Lin, Yi-Hung; Huang, Yen-Chieh; Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Chang, Wen-Chang, E-mail: wchang@ntu.edu.tw [Institute of Biological Chemistry, National Taiwan University, Taipei 110,Taiwan (China); Chen, Chun-Jung, E-mail: wchang@ntu.edu.tw [Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China)

    2007-06-01

    The crystallization of branched-chain aminotransferase from D. radiodurans is described. The branched-chain amino-acid aminotransferase (BCAT), which requires pyridoxal 5′-phosphate (PLP) as a cofactor, is a key enzyme in the biosynthetic pathway of the hydrophobic amino acids leucine, isoleucine and valine. DrBCAT from Deinococcus radiodurans, which has a molecular weight of 40.9 kDa, was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data to 2.50 Å resolution from a DrBCAT crystal, the crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 56.37, b = 90.70, c = 155.47 Å. Preliminary analysis indicates the presence of two DrBCAT molecules in the asymmetric unit, with a solvent content of 47.52%.

  11. Parameters of surface and bulk transonic acoustic waves in hexagonal crystals for the {gamma}-geometry

    Energy Technology Data Exchange (ETDEWEB)

    Alshits, V.I.; Gorkunova, A.S.; Shuvalov, A.L. [Russian Academy of Sciences, Moscow (Russian Federation)

    1994-12-31

    The characteristics of surface-wave modes with the propagation direction m in the plane of transverse isotropy are studied in a semiifinite hexagonal elastic medium with an arbitrary orientation of a free boundary set by the normal n. The parameters of bulk transonic and limiting elastic waves propagating in an equivalent unbound medium with the energy flux normal to the vector n are determined. Possible types of configurations of the refraction sheets in the cross section by a sagittal plane (m,n) and their relation to the parameters of the surface as well as limiting volume modes are analyzed. 14 refs., 4 figs.

  12. Crystallization and preliminary crystallographic analysis of a family 43 β-d-xylosidase from Geobacillus stearothermophilus T-6

    Energy Technology Data Exchange (ETDEWEB)

    Brüx, Christian; Niefind, Karsten [Institute for Biochemistry, University of Cologne (Germany); Ben-David, Alon; Leon, Maya [Department of Biotechnology and Food Engineering and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Haifa (Israel); Shoham, Gil [Department of Inorganic Chemistry and The Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem (Israel); Shoham, Yuval [Department of Biotechnology and Food Engineering and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Haifa (Israel); Schomburg, Dietmar, E-mail: d.schomburg@uni-koeln.de [Institute for Biochemistry, University of Cologne (Germany)

    2005-12-01

    The crystallization and preliminary X-ray analysis of a β-d-xylosidase from G. stearothermophilus T-6, a family 43 glycoside hydrolase, is described. Native and catalytic inactive mutants of the enzymes were crystallized in two different space groups, orthorhombic P2{sub 1}2{sub 1}2 and tetragonal P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2), using a sensitive cryoprotocol. The latter crystal form diffracted X-rays to a resolution of 2.2 Å. β-d-Xylosidases (EC 3.2.1.37) are hemicellulases that cleave single xylose units from the nonreducing end of xylooligomers. In this study, the crystallization and preliminary X-ray analysis of a β-d-xylosidase from Geobacillus stearothermophilus T-6 (XynB3), a family 43 glycoside hydrolase, is described. XynB3 is a 535-amino-acid protein with a calculated molecular weight of 61 891 Da. Purified recombinant native and catalytic inactive mutant proteins were crystallized and cocrystallized with xylobiose in two different space groups, P2{sub 1}2{sub 1}2 (unit-cell parameters a = 98.32, b = 99.36, c = 258.64 Å) and P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2; unit-cell parameters a = b = 140.15, c = 233.11 Å), depending on the detergent. Transferring crystals to cryoconditions required a very careful protocol. Orthorhombic crystals diffract to 2.5 Å and tetragonal crystals to 2.2 Å.

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

    Science.gov (United States)

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

    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 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.

  14. Electron paramagnetic resonance parameters of Mn4+ ion in h-BaTiO3 crystal from a two-mechanism model

    Indian Academy of Sciences (India)

    Wu Xiao-Xuan; Fang Wang; Feng Wen-Lin; Zheng Wen-Chen

    2009-03-01

    The EPR parameters ( factors ∥, ⊥ and zero-field splitting ) of Mn4+ ion in h-BaTiO3 crystal are calculated from the complete high-order perturbation formulas based on a two-mechanism model for the EPR parameters of 33 ions in trigonal symmetry. In the model, not only the widely used crystal-field mechanism, but also the charge-transfer mechanism (which is not considered in crystal-field theory) are included. The calculated results are in reasonable agreement with the experimental values. The relative importance of charge-transfer mechanism to EPR parameters and the defect structure of Mn4+ centre in h-BaTiO3 crystal obtained from the calculations are discussed.

  15. Laboratory longitudinal diffusion tests: 2. Parameter estimation by inverse analysis

    Science.gov (United States)

    Takeda, M.; Zhang, M.; Nakajima, H.; Hiratsuka, T.

    2008-04-01

    This study focuses on the verification of test interpretations for different state analyses of diffusion experiments. Part 1 of this study identified that steady, quasi-steady and equilibrium state analyses for the through- and in-diffusion tests with solution reservoirs are generally feasible where the tracer is not highly sorptive. In Part 2 we investigate parameter identifiability in transient-state analysis of reservoir concentration variation using a numerical approach. For increased generality, the analytical models, objective functions and Jacobian matrix necessary for inverse analysis of transient-state data are reformulated using unified dimensionless parameters. In these dimensionless forms, the number of unknown parameters is reduced and a single dimensionless parameter represents the sorption property. The dimensionless objective functions are evaluated for individual test methods and parameter identifiability is discussed in relation to the sorption property. The effects of multiple minima and measurement error on parameter identifiability are also investigated. The main findings are that inverse problems for inlet and outlet reservoir concentration analyses are generally unstable and well-posed, respectively. Where the tracer is sorptive, the inverse problem for the inlet reservoir concentration analysis may have multiple minima. When insufficient measurement data is collected, multiple solutions may result and this should be taken into consideration when inversely analyzing data including that of inlet reservoir concentration. Verification of test interpretation by cross-checking different state analyses is feasible where the tracer is not highly sorptive. In an actual experiment, test interpretation validity is demonstrated through consistency between theory and practice for different state analyses.

  16. Modeling and simulation of HTS cables for scattering parameter analysis

    Science.gov (United States)

    Bang, Su Sik; Lee, Geon Seok; Kwon, Gu-Young; Lee, Yeong Ho; Chang, Seung Jin; Lee, Chun-Kwon; Sohn, Songho; Park, Kijun; Shin, Yong-June

    2016-11-01

    Most of modeling and simulation of high temperature superconducting (HTS) cables are inadequate for high frequency analysis since focus of the simulation's frequency is fundamental frequency of the power grid, which does not reflect transient characteristic. However, high frequency analysis is essential process to research the HTS cables transient for protection and diagnosis of the HTS cables. Thus, this paper proposes a new approach for modeling and simulation of HTS cables to derive the scattering parameter (S-parameter), an effective high frequency analysis, for transient wave propagation characteristics in high frequency range. The parameters sweeping method is used to validate the simulation results to the measured data given by a network analyzer (NA). This paper also presents the effects of the cable-to-NA connector in order to minimize the error between the simulated and the measured data under ambient and superconductive conditions. Based on the proposed modeling and simulation technique, S-parameters of long-distance HTS cables can be accurately derived in wide range of frequency. The results of proposed modeling and simulation can yield the characteristics of the HTS cables and will contribute to analyze the HTS cables.

  17. Structural parameter identifiability analysis for dynamic reaction networks

    DEFF Research Database (Denmark)

    Davidescu, Florin Paul; Jørgensen, Sten Bay

    2008-01-01

    . The proposed analysis is performed in two phases. The first phase determines the structurally identifiable reaction rates based on reaction network stoichiometry. The second phase assesses the structural parameter identifiability of the specific kinetic rate expressions using a generating series expansion...... method based on Lie derivatives. The proposed systematic two phase methodology is illustrated on a mass action based model for an enzymatically catalyzed reaction pathway network where only a limited set of variables is measured. The methodology clearly pinpoints the structurally identifiable parameters...

  18. Preparation, Crystal Structure, and Thermal Analysis of Carbohydrazide Trinitrophloroglucinolate

    Institute of Scientific and Technical Information of China (English)

    LIU Zhen-hua; ZHANG Tong-lai; HU Xiao-chun; ZHANG Jian-guo; YANG Li; QIAO Xiao-jing

    2008-01-01

    A new compound (CHZ)(HTNPG).0.5H2O was synthesized by mixing carbohydrazide(CHZ) and trinitrophloroglucinol(TNPG) and characterized by elemental analysis and Fourier transform infrared (FTIR) spectrum.Its crystal structure was determined by single crystal X-ray diffraction analysis.The crystal belongs to triclinic system,P1 space group,with a=0.45578(9) nm,b=1.0142(2) nm,c=1.3041(3) nm,a=86.53(3)°,β=99.56(3)°,γ=81.94(3)°,V=0.5958(2) nm3,Z=2,Dc=2.008 g/cm3,R1=0.0476,and wR2=O.1139.The compound is a di-substituted salt of TNPG,which consists of a cation (CHZ)2+ and an anion (HTNPG)2-.The thermal analysis of the compound was studied by means of differential scanning calorimetry(DSC) and thermogravimetry-derivative thermogravimetry(TG-DTG).Under nitrogen atmosphere at a heating rate of 10 ℃/min,the thermal decomposition of the compound contained one endothermic process of dehydrating stage and two intense exothermic decomposition processes in a temperature range of 140--232℃ on the DSC trace.The decomposition products of the title compound are nearly gaseous products.The existing complicated hydrogen bond networks and electrostatic attraction between (CHZ)2+ and (HTNPG)2-enhance the thermal stability of the title compound.

  19. Capillary-Seeding Crystallization and Preliminary Crystallographic Analysis of a Solvent-Tolerant Elastase from Pseudomonas aeruginosa Strain K

    Directory of Open Access Journals (Sweden)

    Abu Bakar Salleh

    2013-08-01

    Full Text Available Seeding is a versatile method for optimizing crystal growth. Coupling this technique with capillary counter diffusion crystallization enhances the size and diffraction quality of the crystals. In this article, crystals for organic solvent-tolerant recombinant elastase strain K were successfully produced through microseeding with capillary counter-diffusion crystallization. This technique improved the nucleation success rate with a low protein concentration (3.00 mg/mL. The crystal was grown in 1 M ammonium phosphate monobasic and 0.1 M sodium citrate tribasic dihydrate pH 5.6. The optimized crystal size was 1 × 0.1 × 0.05 mm3. Elastase strain K successfully diffracted up to 1.39 Å at SPring-8, Japan, using synchrotron radiation for preliminary data diffraction analysis. The space group was determined to be monoclinic space group P1211 with unit cell parameters of a = 38.99 Ǻ, b = 90.173 Å and c = 40.60 Å.

  20. Statistical analysis of crystallization database links protein physico-chemical features with crystallization mechanisms.

    Directory of Open Access Journals (Sweden)

    Diana Fusco

    Full Text Available X-ray crystallography is the predominant method for obtaining atomic-scale information about biological macromolecules. Despite the success of the technique, obtaining well diffracting crystals still critically limits going from protein to structure. In practice, the crystallization process proceeds through knowledge-informed empiricism. Better physico-chemical understanding remains elusive because of the large number of variables involved, hence little guidance is available to systematically identify solution conditions that promote crystallization. To help determine relationships between macromolecular properties and their crystallization propensity, we have trained statistical models on samples for 182 proteins supplied by the Northeast Structural Genomics consortium. Gaussian processes, which capture trends beyond the reach of linear statistical models, distinguish between two main physico-chemical mechanisms driving crystallization. One is characterized by low levels of side chain entropy and has been extensively reported in the literature. The other identifies specific electrostatic interactions not previously described in the crystallization context. Because evidence for two distinct mechanisms can be gleaned both from crystal contacts and from solution conditions leading to successful crystallization, the model offers future avenues for optimizing crystallization screens based on partial structural information. The availability of crystallization data coupled with structural outcomes analyzed through state-of-the-art statistical models may thus guide macromolecular crystallization toward a more rational basis.

  1. Comparative Analysis of Visco-elastic Models with Variable Parameters

    Directory of Open Access Journals (Sweden)

    Silviu Nastac

    2010-01-01

    Full Text Available The paper presents a theoretical comparative study for computational behaviour analysis of vibration isolation elements based on viscous and elastic models with variable parameters. The changing of elastic and viscous parameters can be produced by natural timed evolution demo-tion or by heating developed into the elements during their working cycle. It was supposed both linear and non-linear numerical viscous and elastic models, and their combinations. The results show the impor-tance of numerical model tuning with the real behaviour, as such the characteristics linearity, and the essential parameters for damping and rigidity. Multiple comparisons between linear and non-linear simulation cases dignify the basis of numerical model optimization regarding mathematical complexity vs. results reliability.

  2. Influence of Processing Parameters on the Solidification Behavior of Single-Crystal CMSX-4 Superalloy

    Science.gov (United States)

    Wang, Fu; Ma, Dexin; Bogner, Samuel; Bührig-Polaczek, Andreas

    2016-07-01

    The microstructural evolution of a superalloy, single-crystal CMSX-4 solidified at different withdrawal rates was investigated using a directional solidification quenching method. Analyses of the cross-sections within mushy zones generated the evolution of the solid volume fractions ( f s) during the reduction in the temperature and the solidification sequences. At the withdrawal rate of 0.3 mm min-1, f s increases by about 81 pct within the first 23 pct of the solidification interval, whereas it increases by about 64 pct at the withdrawal rate of 0.7 mm min-1. The Bower-Brody-Flemings model can characterize the evolution tendency of f s curve at the lower withdrawal rate, while it can not only describe the changing tendency of f s, but also precisely predict the f s values at higher withdrawal rate. With increasing withdrawal rate, the solidification intervals of the γ dendrite and γ/ γ' eutectics are increased. In addition to this, the forming site of the γ/ γ' eutectic at the lower withdrawal rate lags behind that at the higher withdrawal rate. At both the withdrawal rates the solidification of the γ/ γ' eutectic islands commences with the γ/ γ' core formed on the surface of the γ dendrites, then progressed spatially and developed the coarse γ/ γ' structure.

  3. Important population viability analysis parameters for giant pandas (Aliuropoda melanoleuca)

    Institute of Scientific and Technical Information of China (English)

    Minghao GONG; Yanling SONG; Zhisong YANG; Chen LIN

    2012-01-01

    Population viability analysis (PVA) is a tool to evaluate the risk of extinction for endangered species and aid conservation decision-making.The quality of PVA output is dependent on parameters related to population dynamics and life-history; however,it has been difficult to collect this information for the giant panda (Aliuropoda melanoleuca),a rare and endangered mammal native to China,confined to some 30 fragmented habitat patches.Since giant pandas are long-lived,mature late,have lower reproductive rates,and show little sexual dimorphism,obtaining data to perform adequate PVA has been difficult.Here,we develop a parameter sensitivity index by modeling the dynamics of six giant panda populations in the Minshan Mountains,in order to determine the parameters most influential to giant panda populations.Our data shows that the giant panda populations are most sensitive to changes in four female parameters:initial breeding age,reproductive rate,mortality rate between age 0 and 1,and mortality rate of adults.The parameter sensitivity index strongly correlated with initial population size,as smaller populations were more sensitive to changes in these four variables.This model suggests that demographic parameters of females have more influence on the results of PVA,indicating that females may play a more important role in giant panda population dynamics than males.Consequently,reintroduction of female individuals to a small giant panda population should be a high priority for conservation efforts.Our findings form a technical basis for the coming program of giant panda reintroduction,and inform which parameters are crucial to successfully and feasibly monitoring wild giant panda populations.

  4. Supersymmetry Parameter Analysis: SPA Convention andProject

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Saavedra, J.A.; Ali, A.; Allanach, B.C.; Arnowitt, R.; Baer, H.A.; Bagger, J.A.; Balazs, C.; Barger, V.; Barnett, M.; Bartl, A.; Battaglia, M.; Bechtle, P.; Belanger, G.; Belyaev, A.; Berger, E.L.; Blair, G.; Boos, E.; Carena, M.; Choi, S.Y.; Deppisch, F.; De Roeck, A.; /Lisbon, IST /DESY /Cambridge U., DAMTP /Texas A-M /Florida State

    2005-12-02

    High-precision analyses of supersymmetry parameters aim at reconstructing the fundamental supersymmetric theory and its breaking mechanism. A well defined theoretical framework is needed when higher-order corrections are included. We propose such a scheme, Supersymmetry Parameter Analysis SPA, based on a consistent set of conventions and input parameters. A repository for computer programs is provided which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e{sup +}e{sup -} linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles. In addition, programs for calculating high-precision low energy observables, the density of cold dark matter (CDM) in the universe as well as the cross sections for CDM search experiments are included. The SPA scheme still requires extended efforts on both the theoretical and experimental side before data can be evaluated in the future at the level of the desired precision. We take here an initial step of testing the SPA scheme by applying the techniques involved to a specific supersymmetry reference point.

  5. Sensitivity analysis of influencing parameters in cavern stability

    Institute of Scientific and Technical Information of China (English)

    Abolfazl Abdollahipour; Reza Rahmannejad

    2012-01-01

    In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of cavern,a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2.The stability of cavern has been studied by investigating the side wall deformation.Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation.Also parameters of Hoek-Brown criterion and σc have no sensitivity when cavern is in a perfect elastic state.But in an elasto-plastic state,parameters of Hoek-Brown criterion and σc affect the deformability; such effect becomes more remarkable with increasing plastic area.Other parameters have different sensitivities concerning rock mass quality (RMR).Results have been used to propose the best set of parameters for study on prediction of sidewall displacement.

  6. Growth, structure, spectral properties and crystal-field analysis of monoclinic Nd:YNbO4 single crystal

    Science.gov (United States)

    Ding, Shoujun; Zhang, Qingli; Gao, Jinyun; Liu, Wenpeng; Luo, Jianqiao; Sun, Dunlu; Sun, Guihua; Wang, Xiaofei

    2016-12-01

    A Nd:YNbO4 single crystal was successfully grown by Czochralski (Cz) method, its structural and spectroscopic properties were investigated. The X-ray rocking curve of the (010) diffraction face of Nd:YNbO4 crystal was measured, the full width at half maximum (FWHM) of this diffraction peak is 0.05°, which indicates a high crystalline quality of the as-grown crystal. Its lattice parameters, atomic coordinates and so on were obtained by Rietvield refinement to X-ray diffraction data. According to the Archimedes drainage method, the crystal density of Nd:YNbO4 is calculated to be 5.4 g/cm3. The Mohr‧s hardness value along (010) face was determined to be 6.0. The transmission spectrum along (010) face at room temperature was recorded and the excitation and emission spectra at 8 K were measured. Photoluminescence peaks of Nd:YNbO4 were assigned, and the crystal-field splitting of Nd3+ in YNbO4 was obtained. The fluorescence lifetime of the 4F3/2→4I11/2 transition of Nd3+ in YNbO4 is fitted to be 152 μs These spectroscopic and energy splitting data give an important reference for the research of laser property of Nd:YNbO4 crystal.

  7. Growth, structure, spectral properties and crystal-field analysis of monoclinic Nd:YNbO{sub 4} single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shoujun [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Key Laboratory of Photonic Devices and Materials, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Zhang, Qingli, E-mail: zql@aiofm.ac.cn [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Key Laboratory of Photonic Devices and Materials, Hefei 230031 (China); Gao, Jinyun; Liu, Wenpeng; Luo, Jianqiao; Sun, Dunlu; Sun, Guihua; Wang, Xiaofei [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Key Laboratory of Photonic Devices and Materials, Hefei 230031 (China)

    2016-12-15

    A Nd:YNbO{sub 4} single crystal was successfully grown by Czochralski (Cz) method, its structural and spectroscopic properties were investigated. The X-ray rocking curve of the (010) diffraction face of Nd:YNbO{sub 4} crystal was measured, the full width at half maximum (FWHM) of this diffraction peak is 0.05°, which indicates a high crystalline quality of the as-grown crystal. Its lattice parameters, atomic coordinates and so on were obtained by Rietvield refinement to X-ray diffraction data. According to the Archimedes drainage method, the crystal density of Nd:YNbO{sub 4} is calculated to be 5.4 g/cm{sup 3}. The Mohr′s hardness value along (010) face was determined to be 6.0. The transmission spectrum along (010) face at room temperature was recorded and the excitation and emission spectra at 8 K were measured. Photoluminescence peaks of Nd:YNbO{sub 4} were assigned, and the crystal-field splitting of Nd{sup 3+} in YNbO{sub 4} was obtained. The fluorescence lifetime of the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition of Nd{sup 3+} in YNbO{sub 4} is fitted to be 152 μs These spectroscopic and energy splitting data give an important reference for the research of laser property of Nd:YNbO{sub 4} crystal.

  8. Crystal growth, Judd–Ofelt analysis and radiative properties of Nd:YAG single crystal grown by HDS

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huaixin, E-mail: guohuaixin@gmail.com; Zhang, Mingfu, E-mail: mfzhang1@hit.edu.cn; Han, Jiecai; Nie, Ying

    2013-08-15

    Nd{sup 3+}-doped Y{sub 3}A{sub l5}O{sub 12} single crystal was successfully grown by horizontal directional solidification (HDS) method; in addition optical absorption and fluorescence spectra were measured at room temperature. Base on the Judd–Ofelt theory, the intensity parameters of Nd{sup 3+} in YAG crystal grown by HDS were determined, and then three spectroscopic parameter Ω{sub t} (t=2,4,6), radiative transition probabilities, radiative lifetime and branching ratios were obtained according to the absorption spectra and fluorescence spectra, and the results were discussed as well. Furthermore, the stimulated emission cross-section of {sup 4}F{sub 3/2}–{sup 4}I{sub 11/2} transition of Nd{sup 3+} in YAG crystal grown by the HDS technique was calculated as 17.86×10{sup −20} cm{sup 2}. In comparison with Nd:YAG crystal grown by the Czochraiski technique, those results indicated that lowly Nd{sup 3+}-doped YAG crystal grown by HDS method had highly efficient stimulated emission for laser materials. -- Highlights: ► The intensity parameters of Nd{sup 3+} in YAG crystal grown by the HDS were determined base on the Judd–Ofelt theory. ► The spectroscopic quality factor Ω{sub 4}/Ω{sub 6} was stimulated to be 0.6497. ► Radiative transition probabilities, radiative lifetime and branching ratios were estimated. ► The emission cross-section calculated for the {sup 4}F{sub 3/2}→{sup 4}I{sub 11/2} transition was 17.86×10{sup −20} cm{sup 2}.

  9. Bloch-mode analysis for effective parameters restoration

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Andryieuski, Andrei; Ha, Sangwoo

    2012-01-01

    We utilize the Bloch-mode analysis of periodic composite structures to introduce an approach for retrieving effective parameters of homogenized metamaterials. In the case of single-mode propagation we can restore a complex effective refractive index with a high accuracy. By further employing...... on the nature of microfields returned by Maxwell's solvers, showing that ignoring of difference between magnetic strength and induction lead to incorrect determination of the Poynting vector....

  10. Study of Some Alkanes Thermodynamic Parameters Using New Liquid Crystals Containing Sulfur as Stationary Phases

    Directory of Open Access Journals (Sweden)

    Mebrouk Djedid

    2015-06-01

    Full Text Available Most of the synthesized compounds which have liquid crystalline character in their composition comprise aromatic molecules. Furthermore there are few jobs that replace this type of molecules by inhomogeneous molecules that have LC character. We will replace the aromatic rings by units of 1,3,4-oxadiazole and study the effects of these new components of the transition temperatures and the Thermodynamic characteristics of n- alkanes in these two LC's phases. have been investigated by inverse gas chromatography. The transition temperatures obtained by GC are in good agreement with those found by DSC. The results are interpreted in terms of parameters “b” and related thermodynamic quantities

  11. Measurement of Large Dipolar Couplings of a Liquid Crystal with Terminal Phenyl Rings and Estimation of the Order Parameters.

    Science.gov (United States)

    Kumar, R V Sudheer; Ramanathan, Krishna V

    2015-07-20

    NMR spectroscopy is a powerful means of studying liquid-crystalline systems at atomic resolutions. Of the many parameters that can provide information on the dynamics and order of the systems, (1) H-(13) C dipolar couplings are an important means of obtaining such information. Depending on the details of the molecular structure and the magnitude of the order parameters, the dipolar couplings can vary over a wide range of values. Thus the method employed to estimate the dipolar couplings should be capable of estimating both large and small dipolar couplings at the same time. For this purpose, we consider here a two-dimensional NMR experiment that works similar to the insensitive nuclei enhanced by polarization transfer (INEPT) experiment in solution. With the incorporation of a modification proposed earlier for experiments with low radio frequency power, the scheme is observed to enable a wide range of dipolar couplings to be estimated at the same time. We utilized this approach to obtain dipolar couplings in a liquid crystal with phenyl rings attached to either end of the molecule, and estimated its local order parameters.

  12. Investigations of the EPR parameters and local lattice structure for the rhombic Cu{sup 2+} centre in TZSH crystal

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao-Ying; Liu, Shi-Fei; Fu, Jin-Xian [Shangrao Normal University, Jiangxi (China). School of Physics and Electronic Information

    2016-07-01

    The electron paramagnetic resonance (EPR) parameters [i.e. g factors g{sub i} (i=x, y, z) and hyperfine structure constants A{sub i}] and the local lattice structure for the Cu{sup 2+} centre in Tl{sub 2}Zn(SO{sub 4}){sub 2}.6H{sub 2}O (TZSH) crystal were theoretically investigated by utilising the perturbation formulae of these parameters for a 3d{sup 9} ion under rhombically elongated octahedra. In the calculations, the admixture of d orbitals in the ground state and the ligand orbital and spin-orbit coupling interactions are taken into account based on the cluster approach. The theoretical EPR parameters show good agreement with the observed values, and the Cu{sup 2+}-H{sub 2}O bond lengths are obtained as follows: R{sub x}∼1.98 Aa, R{sub y}∼2.09 Aa, R{sub z}∼2.32 Aa. The results are discussed.

  13. Analysis of submicron-sized niflumic acid crystals prepared by electrospray crystallization.

    Science.gov (United States)

    Ambrus, Rita; Radacsi, Norbert; Szunyogh, Tímea; van der Heijden, Antoine E D M; Ter Horst, Joop H; Szabó-Révész, Piroska

    2013-03-25

    Interest in submicron-sized drug particles has emerged from both laboratory and industrial perspectives in the last decade. Production of crystals in the nano size scale offers a novel way to particles for drug formulation solving formulation problems of drugs with low solubility in class II of the Biopharmaceutical Classification System. In this work niflumic acid nanoparticles with a size range of 200-800nm were produced by the novel crystallization method, electrospray crystallization. Their properties were compared to those from evaporative and anti-solvent crystallizations, using the same organic solvent, acetone. There is a remarkable difference in the product crystal size depending on the applied methods. The size and morphology were analyzed by scanning electron microscopy and laser diffraction. The structure of the samples was investigated using differential scanning calorimetry, Fourier-transformed infrared spectroscopy and X-ray powder diffraction. The particles produced using electrospray crystallization process were probably changing from amorphous to crystalline state after the procedure.

  14. Investigation of design parameters and choice of substrate resistivity and crystal orientation for the CMS silicon microstrip detector

    CERN Document Server

    Braibant, S

    2000-01-01

    The electrical characteristics ( interstrip and backplane capacitance, leakage current, depletion and breakdown voltage) of silicon microstrip detectors were measured for strip pitches between 60 um and 240 um and various strip implant and metal widths on multi-geometry devices. Both AC and DC coupled devices wereinvestigated. Measurements on detectors were performed before and after irradiation with 24 GeV/c protons up to a fluence of 4.1x10E14 cm-2. We found that the total strip capacitance can be parametrized as a linear function of the ratio of the implant width over the read-out pitch only. We found a significant increase in the interstrip capacitance after radiation on detectors with standard <111> crystal orientation but not on sensors with <100> crystal orientation. We analyzed the measured depletion voltages as a function of the detector geometrical parameters ( read-out pitch, strip width and substrate thickness) found in the literature and we found a linear dependence in...

  15. Parameter analysis calculation on characteristics of portable FAST reactor

    Energy Technology Data Exchange (ETDEWEB)

    Otsubo, Akira; Kowata, Yasuki [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-06-01

    In this report, we performed a parameter survey analysis by using the analysis program code STEDFAST (Space, TErrestrial and Deep sea FAST reactor-gas turbine system). Concerning the deep sea fast reactor-gas turbine system, calculations with many variable parameters were performed on the base case of a NaK cooled reactor of 40 kWe. We aimed at total equipment weight and surface area necessary to remove heat from the system as important values of the characteristics of the system. Electric generation power and the material of a pressure hull were specially influential for the weight. The electric generation power, reactor outlet/inlet temperatures, a natural convection heat transfer coefficient of sea water were specially influential for the area. Concerning the space reactor-gas turbine system, the calculations with the variable parameters of compressor inlet temperature, reactor outlet/inlet temperatures and turbine inlet pressure were performed on the base case of a Na cooled reactor of 40 kWe. The first and the second variable parameters were influential for the total equipment weight of the important characteristic of the system. Concerning the terrestrial fast reactor-gas turbine system, the calculations with the variable parameters of heat transferred pipe number in a heat exchanger to produce hot water of 100degC for cogeneration, compressor stage number and the kind of primary coolant material were performed on the base case of a Pb cooled reactor of 100 MWt. In the comparison of calculational results for Pb and Na of primary coolant material, the primary coolant weight flow rate was naturally large for the former case compared with for the latter case because density is very different between them. (J.P.N.)

  16. Determination of thermodynamic parameters for enolization reaction of malonic and metylmalonic acids by using quartz crystal microbalance

    Directory of Open Access Journals (Sweden)

    Minoru Yoshimoto

    2016-06-01

    Full Text Available We investigated the process of a bromination reaction of malonic acid and methylmalonic acid in the Belousov-Zhabotinsky reaction by using a quartz crystal microbalance (QCM. The process involves an enolization reaction as a rate-determining step. We found that, in the step, the variation of Br2 concentration induced an exactly quantitative shift of a resonant frequency of the QCM, based on the change of the surface mass on the QCM and the solution viscosity and density. This new finding enabled us to estimate the reaction rate constants and the thermodynamic parameters of the enolization reaction due to a QCM measurement. The values measured by the QCM were in good agreement with those measured by a UV-spectrophotometer. As a result, we succeeded to develop a new measurement method of a nonlinear chemical reaction.

  17. Spectral Parameters of Nd3+ in the Nd3+:GdMgB5O10 Crystal

    Institute of Scientific and Technical Information of China (English)

    FAN Jun-Mei; LIN Zhou-Bin; ZHANG Li-Zhen; HU Zu-Shu; WANG Guo-Fu

    2005-01-01

    The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: Ω2 = 2.099×10-20 cm2, Ω4 = 4.599×10-20 cm2 and Ω6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.

  18. ESBP在轧Al单晶体滑移系分析中的应用%Application of EBSP in crystal slip analysis of rolled Al single crystals

    Institute of Scientific and Technical Information of China (English)

    李峥杰; 刘庆

    2002-01-01

    Microstructure and local crystallography of rolled Al crystals were investigated by the electron backscattered pattern (EBSP) technique. A crystal slip analysis was proposed based on the experimental results and Frank formula.

  19. Crystallization and preliminary crystallographic analysis of merohedrally twinned crystals of MJ0729, a CBS-domain protein from Methanococcus jannaschii

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Millán, Pablo; Kortazar, Danel; Lucas, María [Unidad de Cristalografía Macromolecular, CIC bioGUNE, Parque Tecnológico de Vizcaya, Ed. 800, 48160 Derio, Vizcaya (Spain); Martínez-Chantar, María Luz [Unidad de Metabolómica, CIC bioGUNE, Parque Tecnológico de Vizcaya, Ed. 801, 48160 Derio, Vizcaya (Spain); Astigarraga, Egoitz; Fernández, José Andrés [Departamento de Química-Física, Universidad del País Vasco UPV-EHU, Barrio Sarriena s/n, E-48940 Leioa (Spain); Sabas, Olatz [Unidad de Cristalografía Macromolecular, CIC bioGUNE, Parque Tecnológico de Vizcaya, Ed. 800, 48160 Derio, Vizcaya (Spain); Albert, Armando [Instituto de Química-Física ‘Rocasolano’, CSIC, c/Serrano 119, 28006 Madrid (Spain); Mato, Jose M. [Unidad de Metabolómica, CIC bioGUNE, Parque Tecnológico de Vizcaya, Ed. 801, 48160 Derio, Vizcaya (Spain); Martínez-Cruz, Luis Alfonso, E-mail: amartinez@cicbiogune.es [Unidad de Cristalografía Macromolecular, CIC bioGUNE, Parque Tecnológico de Vizcaya, Ed. 800, 48160 Derio, Vizcaya (Spain)

    2008-07-01

    Trigonal crystals of MJ0729 showing different degrees of merohedral twinning that may vary from perfect hemihedral twinning to perfect tetartohedral twinning were obtained upon slight variation of the pH. CBS domains are small protein motifs, usually associated in tandem, that are implicated in binding to adenosyl groups. Several genetic diseases in humans have been associated with mutations in CBS sequences, which has made them very promising targets for rational drug design. Trigonal crystals of the CBS-domain protein MJ0729 from Methanococcus jannaschii were grown by the vapour-diffusion method at acidic pH. Preliminary analysis of nine X-ray diffraction data sets using Yeates statistics and Britton plots showed that slight variation in the pH as well as in the buffer used in the crystallization experiments led to crystals with different degrees of merohedral twinning that may vary from perfect hemihedral twinning to perfect tetartohedral twinning.

  20. Statistical analysis of acoustic wave parameters near active regions

    CERN Document Server

    Soares, M Cristina Rabello; Scherrer, Philip H

    2016-01-01

    In order to quantify the influence of magnetic fields on acoustic mode parameters and flows in and around active regions, we analyse the differences in the parameters in magnetically quiet regions nearby an active region (which we call `nearby regions'), compared with those of quiet regions at the same disc locations for which there are no neighboring active regions. We also compare the mode parameters in active regions with those in comparably located quiet regions. Our analysis is based on ring diagram analysis of all active regions observed by HMI during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the active regions, for which it is about 5.1 mHz. This amplitude enhancement (the `acoustic halo effect') is as large as that observed in the active regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes...

  1. Rescaled range (R/S) analysis on seismic activity parameters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The rescaled range (R/S) analysis, proposed by Hurst, is a newstatistical method. Being different from traditional statistical method, R/S analysis can provide the information of maximum fluctuation (range) of statistical parame-ters. At present paper, several modern instrumental earthquake catalogues in different spatial scale, temporal scale, and with different seismic activity background are studied, and R/S method is used to analyze the variation of range of seismic parameters such as earthquake frequency, and earthquake time interval. For different seismic parameters, the ratio of range to standard deviation - R/S is a power law function of the length of time, and the exponent H of power law is always greater than 0.5. As we know, H=0.5 is the characteristics of all ideal random processes. Our results indicate that earthquake series is not an ideal Poisson process, on the contrary, the earth-quake as a phenomenon bears dual characteristics of randomicity and regularity, and the greater H departs from 0.5, the more regularity the time series will show, and vice versa. With time scale changing, one can give the conserva-tive estimate of the fluctuation, which might occur in a relatively long time scale, only by using the limited and known time records.

  2. Sensitivity analysis on various parameters for lattice analysis of DUPIC fuel with WIMS-AECL code

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Gyu Hong; Choi, Hang Bok; Park, Jee Won [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    The code WIMS-AECL has been used for the lattice analysis of DUPIC fuel. The lattice parameters calculated by the code is sensitive to the choice of number of parameters, such as the number of tracking lines, number of condensed groups, mesh spacing in the moderator region, other parameters vital to the calculation of probabilities and burnup analysis. We have studied this sensitivity with respect to these parameters and recommend their proper values which are necessary for carrying out the lattice analysis of DUPIC fuel.

  3. Theoretical analysis of a biased photonic crystal fiber infiltrated with a negative dielectric anisotropy liquid crystal

    DEFF Research Database (Denmark)

    Weirich, Johannes; Wei, Lei; Lægsgaard, Jesper;

    2009-01-01

    We simulate the PBG mode of a biased Photonic Crystal Fiber (PCF) infiltrated with a Liquid Crystal (LC) with negative dielectric anisotropy. We analyse the voltage induced change of the transmission spectrum, dispersion and losses and compare them to the experimental values....

  4. Analysis of Shannon entropy for protein crystallization and prediction of crystallization pH and precipitants

    Science.gov (United States)

    Pérez-Priede, Mónica; García-Granda, Santiago

    2017-02-01

    This is a new attempt at analysing crystallization data from Protein Data Bank. In line with the idea that crystallization conditions are intimately related with amino acid sequences, we have computed the Shannon entropy of polypeptides and polynucleotides and we have discovered a relationship between Shannon entropy and molecular weight, and also between the entropy of polypeptides, and the precipitants used in crystallization experiments. In fact, the Shannon entropy and the molecular weight of proteins are good precipitant predictors. On the other hand, we have proposed the hypothesis that homologous proteins may have similar crystallization conditions, and we have tried to find evidence that supports it, predicting the crystallization pH of a large amount of polypeptide sequences by means of a nearest neighbour approach combined with local sequence alignment.

  5. Statistical Analysis of Acoustic Wave Parameters Near Solar Active Regions

    Science.gov (United States)

    Rabello-Soares, M. Cristina; Bogart, Richard S.; Scherrer, Philip H.

    2016-08-01

    In order to quantify the influence of magnetic fields on acoustic mode parameters and flows in and around active regions, we analyze the differences in the parameters in magnetically quiet regions nearby an active region (which we call “nearby regions”), compared with those of quiet regions at the same disk locations for which there are no neighboring active regions. We also compare the mode parameters in active regions with those in comparably located quiet regions. Our analysis is based on ring-diagram analysis of all active regions observed by the Helioseismic and Magnetic Imager (HMI) during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the active regions, for which it is about 5.1 mHz. This amplitude enhacement (the “acoustic halo effect”) is as large as that observed in the active regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes from a deficit to an excess at around 4.2 mHz, but averages to zero over all modes. The frequency difference in nearby regions increases with increasing frequency until a point at which the frequency shifts turn over sharply, as in active regions. However, this turnover occurs around 4.9 mHz, which is significantly below the acoustic cutoff frequency. Inverting the horizontal flow parameters in the direction of the neigboring active regions, we find flows that are consistent with a model of the thermal energy flow being blocked directly below the active region.

  6. Relationships between the surface quality of a single crystal copper ingot and the process parameters of a heated mould continuous casting method

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The relationships between the surface quality of a single crystal copper ingot and the process parameters of heated mould continuous casting method were studied experimentally using our own design of horizontal heated mould continuous casting apparatus, and the mechanism by which process parameters affect the surface quality of a single crystal copper ingot is analyzed in the present paper. The results show that the process parameters affect the surface quality of a pure copper ingot by affecting the position of the liquid-solid interface in the mould. The position of the liquid-solid interface in the mould must be controlled carefully within an appropriate range, which is determined through a series of experiments,in order to gain a single crystal copper ingot with good surface quality.

  7. Crystallization and preliminary crystallographic analysis of 2-aminophenol 1,6-dioxygenase complexed with substrate and with an inhibitor.

    Science.gov (United States)

    Li, De-Feng; Zhang, Jia-Yue; Hou, Yanjie; Liu, Lei; Liu, Shuang-Jiang; Liu, Wei

    2012-11-01

    Dioxygen activation implemented by nonhaem Fe(II) enzymes containing the 2-His-1-carboxylate facial triad has been extensively studied in recent years. Extradiol dioxygenase is the archetypal member of this superfamily and catalyzes the oxygenolytic ring opening of catechol analogues. Here, the crystallization and preliminary X-ray analysis of 2-aminophenol 1,6-dioxygenase, an enzyme representing a minor subset of extradiol dioxygenases that catalyze the fission of 2-aminophenol rather than catecholic compounds, is reported. Crystals of the holoenzyme with FeII and of complexes with the substrate 2-aminophenol and the suicide inhibitor 4-nitrocatechol were grown using the cocrystallization method under the same conditions as used for the crystallization of the apoenzyme. The crystals belonged to space group C2 and diffracted to 2.3-2.7 Å resolution; the crystal that diffracted to the highest resolution had unit-cell parameters a=270.24, b=48.39, c=108.55 Å, β=109.57°. All X-ray data sets collected from diffraction-quality crystals were suitable for structure determination.

  8. Phenylacetic acid co-crystals with acridine, caffeine, isonicotinamide and nicotinamide: Crystal structures, thermal analysis, FTIR spectroscopy and Hirshfeld surface analysis

    Science.gov (United States)

    Amombo Noa, Francoise M.; Jacobs, Ayesha

    2017-07-01

    Co-crystals of phenylacetic acid (PAA) with acridine (ACR), caffeine (CAF), isonicotinamide (INM) and nicotinamide (NAM) have been successfully prepared and characterised by single crystal X-ray diffraction, FTIR spectroscopy, thermal analysis and Hirshfeld surface analysis. The ACR, INM and NAM co-crystals with PAA exhibit the carboxylic acid-pyridine heterosynthon. Furthermore the amide-amide supramolecular homosynthon is observed in the PAA co-crystals with INM and NAM as well as Nsbnd H⋯O interactions between the acid and the respective base. The CAF co-crystal exhibits hydrogen bonding between the imidazole nitrogen and the COOH group of the PAA. The compounds demonstrate different stoichiometries; for PAA·ACR and PAA·INM a 1:1 ratio is displayed, a 2:1 in 2PAA·CAF and a 2:2 in the case of 2PAA·2NAM.

  9. Local structure distortion and spin Hamiltonian parameters for Cr3+-VZn tetragonal defect centre in Cr3+ doped KZnF3 crystal

    Institute of Scientific and Technical Information of China (English)

    Yang Zi-Yuan

    2011-01-01

    The quantitative relationship between the spin Hamiltonian parameters (D,g1l,Og) and the crystal structure parameters for the Cr3+-VZ,,tetragonal defect centre in a Cr3+:KZnF3 crystal is established by using the superposition model. On the above basis,the local structure distortion and the spin Hamiltonian parameter for the Cr3+-VZn tetragonal defect centre in the KZnF3 crystal are systematically investigated using the complete diagonalization method.It is found that the Vzn vacancy and the differences in mass,radius and charge between the Cr3+ and the Zn2+ ions induce the local lattice distortion of the Cr3+ centre ions in the KZnF3 crystal. The local lattice distortion is shown to give rise to the tetragonal crystal field,which in turn results in the tetragonal zero-field splitting parameter D and the anisotropic g factor △g. We find that the ligand F-ion along [001]and the other five F-ions move towards the central Cr3+ by distances of △l=0.0121 nm and △2=0.0026 nm,respectively. Our approach takes into account the spin-orbit interaction as well as the spin-spin,spin-other-orbit,and orbit-orbit interactions omitted in the previous studies. It is found that for the Cr3+ ions in the Cr3+:KZnF3 crystal,although the spin-orbit mechanism is the most important one,the contribution to the spin Hamiltonian parameters from the other three mechanisms,including spin-spin,spin-other-orbit,and orbit-orbit magnetic interactions,is appreciable and should not be omitted,especially for the zero-field splitting (ZFS) parameter D.

  10. Analysis of acoustic emission effect accompanying metal crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Vorontsov, V B [Urals State University of Railway Transport (USURT), 66 Kolmogorov Street, Ekaterinburg, 620034 (Russian Federation); Katalnikov, V V [Ural State Technical University (USTU), 19 Mira St, Ekaterinburg, 620002 (Russian Federation)], E-mail: vorontsov@bgd.usart.ru, E-mail: vdeka@mail.ru

    2008-02-15

    The work is devoted to acoustic emission (AE) which occurs in the process of crystallization of metals and non-organic substances. The objective of the research is to obtain an AE signal from the interphase surface and carry out frequency analysis of the spectrum. The results of the research have shown that the signals generated have maximum amplitude in 21-27 kHz range with maximums at 21 and 24 kHz at v=0,8 cm/sec and at 21 and 23 kHz at v=1,43 cm/sec. To explain the results obtained the cluster model of melts was applied. Every AE signal corresponds to the advance of interphase surface by a step equal to 3 layers of clusters.

  11. Investigations on nucleation thermodynamical parameters of NdBa2Cu3O7– (Nd123) crystallization by high temperature solution growth

    Indian Academy of Sciences (India)

    D P Paul; R Jayavel; C Subramanian; P Ramasamy

    2000-04-01

    Investigations on nucleation thermodynamical parameters are very essential for the successful growth of good quality single crystals from high temperature solution. A theoretical estimation of the nucleation thermodynamical parameters like interfacial energy between the solid Nd123 and its flux BaO–CuO, metastable zone-width, Gibbs free energy, critical energy barrier for nucleation and critical nucleation radius have been calculated from the knowledge of solubility data and by applying the classical nucleation theory. Results are discussed to understand the growth kinetics of Nd123 crystals.

  12. Theoretical studies of the spin-Hamiltonian parameters for the orthorhombic Pr4+ centers in Sr2CeO4 crystals

    Indian Academy of Sciences (India)

    Wen-Lin Feng

    2008-04-01

    Theoretical studies of spin-Hamiltonian (SH) parameters associated with Pr4+ in Sr2CeO4 single crystals have been made by using the complete diagonalizing energy matrix method (CDM) for the 41 electronic configuration. The calculated results are in excellent agreement with the experimental data. The negative signs of the anisotropic -factors and hyperfine structure constants (where = || or ⊥) for the orthorhombic Pr4+ ion in Sr2CeO4 are suggested from the calculations. By comparing the results obtained by the CDM with the experimental data, one finds it is valid to interpret the SH parameters for 41 ions in crystals. The results are discussed.

  13. Crystallization and Preliminary X-ray Diffraction Analysis of Salmonella typhi PilS

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna,A.; Tan, Y.; Mok, H.; Saxena, A.; Swaminathan, K.

    2006-01-01

    The structure determination of PilS, a type IV pilin, by X-ray crystallography is reported. The recombinant protein from Salmonella typhi was overexpressed, purified and crystallized. The crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 77.88, b = 114.53, c = 31.75 {angstrom}. The selenomethionine derivative of the PilS protein was overexpressed, purified and crystallized in the same space group. Data sets have been collected to 2.1 {angstrom} resolution from the selenomethionine-derivative crystal using synchrotron radiation for multiwavelength anomalous dispersion (MAD) phasing.

  14. Analysis on optical bistability parameters in photonic switching devices

    Science.gov (United States)

    Sarafraz, Hossein; Sayeh, Mohammad R.

    2016-06-01

    An investigation has been done on the parameters of a hysteretic bistable optical Schmitt trigger device. From a design point of view, it is important to know the regions where this bistability occurs and is fully functional with respect to its subsystem parameters. Otherwise experimentally reaching such behavior will be very time-consuming and frustrating, especially with multiple devices employed in a single photonic circuit. A photonic Schmitt trigger consisting of two feedbacked inverting amplifiers, each characterized by -m (slope), A (y-intercept), and B (constant base) parameters is considered. This system is investigated dynamically with a varying input to find its stable and unstable states both mathematically and with simulation. In addition to a complete mathematical analysis of the system, we also describe how m, A, and B can be properly chosen in order to satisfy certain system conditions that result in bistability. More restrictions are also imposed to these absolute conditions by the system conditions as will be discussed. Finally, all results are verified in a more realistic photonic simulation.

  15. Anisotropic parameter estimation using velocity variation with offset analysis

    Energy Technology Data Exchange (ETDEWEB)

    Herawati, I.; Saladin, M.; Pranowo, W.; Winardhie, S.; Priyono, A. [Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, 40132 (Indonesia)

    2013-09-09

    Seismic anisotropy is defined as velocity dependent upon angle or offset. Knowledge about anisotropy effect on seismic data is important in amplitude analysis, stacking process and time to depth conversion. Due to this anisotropic effect, reflector can not be flattened using single velocity based on hyperbolic moveout equation. Therefore, after normal moveout correction, there will still be residual moveout that relates to velocity information. This research aims to obtain anisotropic parameters, ε and δ, using two proposed methods. The first method is called velocity variation with offset (VVO) which is based on simplification of weak anisotropy equation. In VVO method, velocity at each offset is calculated and plotted to obtain vertical velocity and parameter δ. The second method is inversion method using linear approach where vertical velocity, δ, and ε is estimated simultaneously. Both methods are tested on synthetic models using ray-tracing forward modelling. Results show that δ value can be estimated appropriately using both methods. Meanwhile, inversion based method give better estimation for obtaining ε value. This study shows that estimation on anisotropic parameters rely on the accuracy of normal moveout velocity, residual moveout and offset to angle transformation.

  16. Purification, crystallization and preliminary X-ray crystallographic analysis of rice Bowman–Birk inhibitor from Oryza sativa

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Hung [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Li, Hsin-Tai [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Huang, Yen-Chieh [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Hsieh, Ying-Cheng; Guan, Hong-Hsiang [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Chang, Tschining; Wang, Andrew H.-J., E-mail: ahjwang@gate.sinica.edu.tw [Institute of Biological Chemistry, Academia Sinica, Taipei 11529,Taiwan (China); Chen, Chun-Jung, E-mail: ahjwang@gate.sinica.edu.tw [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China)

    2006-06-01

    Rice Bowman–Birk inhibitor was expressed and crystallized. Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 74.37, b = 96.69, c = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%.

  17. Crystallization and preliminary X-ray diffraction analysis of an anti-H(O) lectin from Lotus tetragonolobus seeds.

    Science.gov (United States)

    Moreno, Frederico Bruno Mendes Batista; Martil, Daiana Evelin; Cavada, Benildo Sousa; de Azevedo, Walter Filgueira

    2006-07-01

    The seed lectin from Lotus tetragonolobus (LTA) has been crystallized. The best crystals grew over several days and were obtained using the vapour-diffusion method at a constant temperature of 293 K. A complete structural data set was collected at 2.00 angstroms resolution using a synchrotron-radiation source. LTA crystals were found to be monoclinic, belonging to space group P2(1), with unit-cell parameters a = 68.89, b = 65.83, c = 102.53 angstroms, alpha = gamma = 90, beta = 92 degrees. Molecular replacement yielded a solution with a correlation coefficient and R factor of 34.4 and 51.6%, respectively. Preliminary analysis of the molecular-replacement solution indicates a new quaternary association in the LTA structure. Crystallographic refinement is under way.

  18. Expression, purification, crystallization and preliminary X-ray analysis of the cathelicidin motif of the protegrin-3 precursor.

    Science.gov (United States)

    Sanchez, J F; Hoh, F; Strub, M P; Strub, J M; Van Dorsselaer, A; Lehrer, R; Ganz, T; Chavanieu, A; Calas, B; Dumas, C; Aumelas, A

    2001-11-01

    Numerous precursors of antibacterial peptides with unrelated sequences share a similar prosequence which belongs to the cathelicidin family of proteins. The three-dimensional structure of this cathelicidin motif, which contains two disulfide bonds, has not yet been reported. The cathelicidin motif (ProS) of the protegrin-3 precursor was overexpressed in Escherichia coli as a His-tagged protein. The His(6) tag was removed by thrombin cleavage. ProS was purified to homogeneity and single crystals were obtained by the hanging-drop vapour-diffusion method at pH 3-4. Preliminary X-ray diffraction analysis indicated that these crystals belong to the hexagonal space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 51.42, c = 134.25 A. These crystals diffracted beyond 2.75 A (1.9 A at ESRF) and contain one molecule per asymmetric unit.

  19. Analysis of Network Parameters Influencing Performance of Hybrid Multimedia Networks

    Directory of Open Access Journals (Sweden)

    Dominik Kovac

    2013-10-01

    Full Text Available Multimedia networks is an emerging subject that currently attracts the attention of research and industrial communities. This environment provides new entertainment services and business opportunities merged with all well-known network services like VoIP calls or file transfers. Such a heterogeneous system has to be able satisfy all network and end-user requirements which are increasing constantly. Therefore the simulation tools enabling deep analysis in order to find the key performance indicators and factors which influence the overall quality for specific network service the most are highly needed. This paper provides a study on the network parameters like communication technology, routing protocol, QoS mechanism, etc. and their effect on the performance of hybrid multimedia network. The analysis was performed in OPNET Modeler environment and the most interesting results are discussed at the end of this paper

  20. Study on characteristic parameters influencing laser-induced damage threshold of KH(2)PO(4) crystal surface machined by single point diamond turning.

    Science.gov (United States)

    Chen, Mingjun; Li, Mingquan; Cheng, Jian; Jiang, Wei; Wang, Jian; Xu, Qiao

    2011-12-01

    It has fundamental meaning to find the elements influencing the laser-induced damage threshold (LIDT) of KH(2)PO(4) (KDP) crystal and to provide suitable characterization parameters for these factors in order to improve the LIDT of KDP. Using single-point diamond turning (SPDT) to process the KDP crystal, the machined surface quality has important effects on its LIDT. However, there are still not suitable characteristic parameters of surface quality of KDP to correspond with the LIDT nowadays. In this paper, guided by the Fourier model theory, we study deeply the relationship between the relevant characteristic parameters of surface topography of KDP crystal and the experimental LIDT. Research results indicate that the waviness rather than the roughness is the leading topography element on the KDP surface machined by the SPDT method when the LIDT is considered and the amplitude of micro-waviness has greater influence on the light intensity inside the KDP crystal within the scope of dangerous frequencies between (180 μm)(-1) and (90 μm)(-1); with suitable testing equipment, the characteristic parameters of waviness amplitude, such as the arithmetical mean deviation of three-dimensional profile S(a) or root mean square deviation of three-dimensional contour S(q), are able to be considered as suitable parameters to reflect the optical quality of the machined surface in order to judge approximately the LIDT of the KDP surface and guide the machining course.

  1. ANALYSIS OF PARAMETERS AFFECTING THE QUALITY OF A CUTTING MACHINE

    Directory of Open Access Journals (Sweden)

    Iveta Onderová

    2014-02-01

    Full Text Available The quality of cutting machines is affected by several factors that can be directly or indirectly influenced by manufacturers, technicians and users of machine tools. The most critical qualitative evaluation parameters of machine tools include accuracy and stability. Investigations of accuracy and repeatable positioning accuracy were essential for the research presented in this paper. The aim was to develop and experimentally verify the design of a methodology for cutting centers aimed at achieving the desired working precision. Before working on the topic described here, it was necessary to make several scientific analyses, which are summarized in this paper. We can build on the initial working hypothesis that by improving the technological parameters (e.g. by increasing the working speed of the machine, or by improving the precision of the positioning the quality of the cutting machine will also be improved. For the purposes of our study, several investigated parameters were set affecting positioning accuracy, such as rigidity, positioning speed, etc. First, the stiffness of the portal structure of the cutting machine was analyzed. FEM analysis was used to investigate several alternative structures of the cutting machine, and also an innovative solution for beam mounting. The second step was to integrate two types of drives into the design of the cutting machine. The first drive is a classic rack and pinion drive for cutting machines. To increase (improve the working speed of the machine, linear motors were designed as an alternative drive. The portal of the cutting machine was designed for a working speed of 260mmin−1 and acceleration of 25 m. s−2. The third step was based on the results of the analysis. In collaboration with Microstep, an experimental cutting machine in a portal version was produced using linear synchronous motors driving the portal on both sides, and with direct linear metering of its position. In the fourth step, an

  2. Analysis of Wave Directional Spreading by Bayesian Parameter Estimation

    Institute of Scientific and Technical Information of China (English)

    钱桦; 莊士贤; 高家俊

    2002-01-01

    A spatial array of wave gauges installed on an observatoion platform has been designed and arranged to measure the lo-cal features of winter monsoon directional waves off Taishi coast of Taiwan. A new method, named the Bayesian ParameterEstimation Method( BPEM), is developed and adopted to determine the main direction and the directional spreading parame-ter of directional spectra. The BPEM could be considered as a regression analysis to find the maximum joint probability ofparameters, which best approximates the observed data from the Bayesian viewpoint. The result of the analysis of field wavedata demonstrates the highly dependency of the characteristics of normalized directional spreading on the wave age. The Mit-suyasu type empirical formula of directional spectnun is therefore modified to be representative of monsoon wave field. More-over, it is suggested that Smax could be expressed as a function of wave steepness. The values of Smax decrease with increas-ing steepness. Finally, a local directional spreading model, which is simple to be utilized in engineering practice, is prop-osed.

  3. Analysis and Evaluation of Cooking Parameters for Sweet Bakery Products

    Directory of Open Access Journals (Sweden)

    Giuseppe Vignali

    2013-07-01

    Full Text Available Cooking process is essential for the preparation of sweet bakery products, such as Panettone, a typical Italian seasonal dessert. This study is aimed at evaluating the features of the finished product leaving the oven chamber using the Design of Experiments technique. Four features of the product like “water activity”, “humidity”, “pH” and “sensorial judge” have been explained as functions of independent variables: recipe of the dough, affecting the dough strength and cooking process parameters, such as time, temperature and oven chamber configuration. A two-level, complete four-factor design has been used to carry out the experiments; consequently the analysis of variance has pointed out the effects of main factors and some of their interaction effects; multiple regression analysis was also carried out to explain the variability and to predict the process. The model can be profitably adopted in order to adjust the cooking process parameters in accordance to the dough recipe or the boundary cooking conditions. This study can be further developed by optimizing the input factors in order to maximize the “overall rating” response of the finished product.

  4. Crystal field energy levels, spin-Hamiltonian parameters and local structures for the Cr3+ and Mn4+ centers in La3Ga5SiO14 crystals

    Science.gov (United States)

    Mei, Yang; Chen, Bo-Wei; Zheng, Wen-Chen; Li, Bang-Xing

    2017-02-01

    The crystal field energy levels (obtained from optical spectra) together with the spin-Hamiltonian parameters g//, g⊥ and D (obtained from EPR spectra) for 3d3 ions Cr3+ and Mn4+ at the trigonal octahedral Ga3+ sites in La3Ga5SiO14 crystals are computed from the complete diagonalization (of energy matrix) method based on the two-spin-orbit-parameter model. The model takes into account the contributions due to the spin-orbit parameter of central dn ion (in the traditional crystal field theory) and that of ligand ions via covalence effect. The calculated results are in rational accord with the experimental values. The calculations also imply that the covalence of (MnO6)8- center in La3Ga5SiO14 crystals is stronger than that of (CrO6)9- center, and the impurity-induced local lattice relaxation for (MnO6)8- center is larger than that for (CrO6)9- cluster because of the larger size and charge mismatch for Mn4+ replacing Ga3+ in La3Ga5SiO14 crystals.

  5. Cloning, purification, crystallization and preliminary crystallographic analysis of SecA from Enterococcus faecalis

    Energy Technology Data Exchange (ETDEWEB)

    Meining, Winfried, E-mail: wim@csb.ki.se [Karolinska Institutet, Department of Biosciences, Center of Structural Biochemistry (Sweden); Scheuring, Johannes; Fischer, Markus; Weinkauf, Sevil [Technische Universität München, Chemistry Department (Germany); Karolinska Institutet, Department of Biosciences, Center of Structural Biochemistry (Sweden)

    2006-06-01

    SecA ATPase from E. faecalis has been cloned, overexpressed, purified and crystallized. Crystals belong to space group C2 and diffract to 2.4 Å resolution. The gene coding for SecA from Enterococcus faecalis was cloned and overexpressed in Escherichia coli. In this protein, the lysine at position 6 was replaced by an asparagine in order to reduce sensitivity towards proteases. The modified protein was purified and crystallized. Crystals diffracting to 2.4 Å resolution were obtained using the vapour-diffusion technique. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 203.4, b = 49.8, c = 100.8 Å, α = γ = 90.0, β = 119.1°. A selenomethionine derivative was prepared and is currently being tested in crystallization trials.

  6. Liquid Crystal Thermography Measurement Uncertainty Analysis and Its Application to Turbulent Heat Transfer Measurements

    Directory of Open Access Journals (Sweden)

    Yu Rao

    2012-01-01

    Full Text Available Liquid crystal thermography is an advanced nonintrusive measurement technique, which is capable of providing a high-accuracy continuous temperature field measurement, especially for a complex structured heat transfer surface. The first part of the paper presents a comprehensive introduction to the thermochromic liquid crystal material and the related liquid crystal thermography technique. Then, based on the aythors' experiences in using the liquid crystal thermography for the heat transfer measurement, the parameters affecting the measurement uncertainty of the liquid crystal thermography have been discussed in detail through an experimental study. The final part of the paper describes the applications of the steady and transient liquid crystal thermography technique in the study of the turbulent flow heat transfer related to the aeroengine turbine blade cooling.

  7. Effect of solidification parameters on the microstructures of a single crystal Ni-based superalloy AM3

    Institute of Scientific and Technical Information of China (English)

    Yu Zhuhuan; Liu Lin; Zhao Xinbao; Zhang Weiguo; Zhang Jun; Fu Hengzhi

    2010-01-01

    A single crystal Ni-based superalloy AM3 was processed at withdraw rates of 3.5, 10, 50, 100, 200, and 500 IJm-s-1, respectively. The as-cast microstructures and solidification segregation ratio were characterized with various withdraw rates. The shape and size of carbide microstructuras were determined. As expected, the primary and secondary dendrite arm spacings (PDAS and SDAS) decrease with the increase of withdraw rate. The highest volume fraction of eutectic γ/γ' is observed at the 100 μm·s-1 withdraw rate. The volume fraction of eutectic γ/γ' does not appear to be a strong function of the withdraw rate. With increasing withdraw rate, interface morphologies change in the sequence of planar, cellular, and dendrite. There is a general refinement of the microstructure as the withdraw rate increases. EPMA analysis showed that withdraw rate does not have obvious influence on the segregation of elements.

  8. Crystal landscape in the orcinol:4,4′-bipyridine system: synthon modularity, polymorphism and transferability of multipole charge density parameters

    Directory of Open Access Journals (Sweden)

    Ritesh Dubey

    2014-01-01

    Full Text Available Polymorphism in the orcinol:4,4′-bipyridine cocrystal system is analyzed in terms of a robust convergent modular phenol...pyridine supramolecular synthon. Employing the Synthon Based Fragments Approach (SBFA to transfer the multipole charge density parameters, it is demonstrated that the crystal landscape can be quantified in terms of intermolecular interaction energies in the five crystal forms so far isolated in this complex system. There are five crystal forms. The first has an open, divergent O—H...N based structure with alternating orcinol and bipyridine molecules. The other four polymorphs have different three-dimensional packing but all of them are similar at an interaction level, and are based on a modular O—H...N mediated supramolecular synthon that consists of two orcinol and two bipyridine molecules in a closed, convergent structure. The SBFA method, which depends on the modularity of synthons, provides good agreement between experiment and theory because it takes into account the supramolecular contribution to charge density. The existence of five crystal forms in this system shows that polymorphism in cocrystals need not be considered to be an unusual phenomenon. Studies of the crystal landscape could lead to an understanding of the kinetic pathways that control the crystallization processes, in other words the valleys in the landscape. These pathways are traditionally not considered in exercises pertaining to computational crystal structure prediction, which rather monitors the thermodynamics of the various stable forms in the system, in other words the peaks in the landscape.

  9. STRUCTURAL CHARACTERIZATION OF POLYETHYLENES BY DSC ANALYSIS AFTER CRYSTALLIZATION SEGREGATION

    Institute of Scientific and Technical Information of China (English)

    Yu Ma; Mao Xu

    2000-01-01

    The molecular structure of polyethylene (PE) samples with various comonomers including propylene, 1-butene and 1-hexene was investigated by DSC and 13C-NMR techniques. The density of the samples varies from 0.948 g/cm3 to 0.917 g/cm3, and the molecular weight determined by the GPC method is in the range of 1~2 × 105. The branch point content of the samples was determined by 13C-NMR measurements and was found to be less than 20 per 1000 C atoms along the main chain. Crystallization segregation DSC technique (CSDSC) was used to characterize the branch point distribution or the segment length distribution of PEs. The crystallization segregation was performed in a successive annealing process at decreasing temperatures. The interval of two successive annealing temperatures was 6 K, and the time length of each annealing step was 2.5 h. The CSDSC results clearly indicate that all the PE samples used, including some metallocene PEs,more or less exhibit their non-uniformity in segment length distribution, and bimodal or multimodal CSDSC curves were usually observed. For quantitative characterization of the CSDSC curves and the segment length distribution two parameters,the average melting point, TmAV, and the root-mean-square deviation of melting temperature, (ATm2AV)1/2, were proposed.TmAV is corresponding to the average segment length due to branching and (ATm2AV)1/2 gives information about the width of the segment length distribution. Experimental results show that both the degree of average melting temperature depression and the width of the distribution seem to increase with increasing the branching content and are dependent on the type of comonomers. Very good reproducibility and additivity of the CSDSC method were evidenced experimentally. It was concluded that the CSDSC technique is a sensitive and convenient method for characterizing the segment length distribution of branched polyethylenes and will be of great interest in structure-property relationship

  10. Analysis of crystallization data in the Protein Data Bank.

    Science.gov (United States)

    Kirkwood, Jobie; Hargreaves, David; O'Keefe, Simon; Wilson, Julie

    2015-10-01

    The Protein Data Bank (PDB) is the largest available repository of solved protein structures and contains a wealth of information on successful crystallization. Many centres have used their own experimental data to draw conclusions about proteins and the conditions in which they crystallize. Here, data from the PDB were used to reanalyse some of these results. The most successful crystallization reagents were identified, the link between solution pH and the isoelectric point of the protein was investigated and the possibility of predicting whether a protein will crystallize was explored.

  11. Crystallization and preliminary X-ray diffraction analysis of a protease inhibitor from the haemolymph of the Indian tasar silkworm Antheraea mylitta

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Sobhan [Department of Biotechnology, Indian Institute of Technology, Kharagpur (India); Aravind, Penmatsa [Centre for Cellular and Molecular Biology, Hyderabad (India); Madhurantakam, Chaithanya; Ghosh, Ananta Kumar [Department of Biotechnology, Indian Institute of Technology, Kharagpur (India); Sankaranarayanan, Rajan, E-mail: sankar@ccmb.res.in [Centre for Cellular and Molecular Biology, Hyderabad (India); Das, Amit Kumar, E-mail: sankar@ccmb.res.in [Department of Biotechnology, Indian Institute of Technology, Kharagpur (India)

    2006-07-01

    The crystallization and preliminary X-ray crystallographic analysis of a protease inhibitor from the haemolymph of the Indian tasar silk worm A. mylitta is reported. A protein with inhibitory activity against fungal proteases was purified from the haemolymph of the Indian tasar silkworm Antheraea mylitta and was crystallized using the hanging-drop vapour-diffusion method. Polyethylene glycol 3350 was used as a precipitant. Crystals belonged to space group P6{sub 3}22, with unit-cell parameters a = b = 60.6, c = 85.1 Å. X-ray diffraction data were collected and processed to a maximum resolution of 2.1 Å.

  12. Theoretical calculations of spin-Hamiltonian parameters for the square planer CuCl4 2 - cluster in Cs2ZrCl6 crystal

    Science.gov (United States)

    Liu, Gang; Mei, Yang; Zhang, Xin-Xin; Zheng, Wen-Chen

    2015-05-01

    The high-order perturbation formulas based on a two-mechanism model (where in addition to the contributions from the crystal-field (CF) mechanism in the usually-applied CF theory, those from the generally-neglected charge-transfer (CT) mechanism are also contained) are employed to calculate the spin-Hamiltonian parameters (g factors g//, g⊥ and the hyperfine structure constants A//, A⊥) of the square planar CuCl4 2 - clusters in Cs2ZrCl6 crystal. The needed CF energy levels in the calculations are obtained from the observed optical spectra. The calculated results show reasonable agreement with the experimented values. The negative sign of A// and positive sign of A⊥ are proposed from the calculations. The calculations also suggest that one should take account of the contributions due to both the CF and CT mechanisms for the exact and rational calculations of spin-Hamiltonian parameters of Cu2+-Cl- combination in crystals.

  13. Crystallization and preliminary crystallographic analysis of merohedrally twinned crystals of MJ0729, a CBS-domain protein from Methanococcus jannaschii

    Science.gov (United States)

    Fernández-Millán, Pablo; Kortazar, Danel; Lucas, María; Martínez-Chantar, María Luz; Astigarraga, Egoitz; Fernández, José Andrés; Sabas, Olatz; Albert, Armando; Mato, Jose M.; Martínez-Cruz, Luis Alfonso

    2008-01-01

    CBS domains are small protein motifs, usually associated in tandem, that are implicated in binding to adenosyl groups. Several genetic diseases in humans have been associated with mutations in CBS sequences, which has made them very promising targets for rational drug design. Trigonal crystals of the CBS-domain protein MJ0729 from Methanococcus jannaschii were grown by the vapour-diffusion method at acidic pH. Preliminary analysis of nine X-ray diffraction data sets using Yeates statistics and Britton plots showed that slight variation in the pH as well as in the buffer used in the crystallization experiments led to crystals with different degrees of merohedral twinning that may vary from perfect hemihedral twinning to perfect tetartohedral twinning. PMID:18607087

  14. Spontaneous piezoelectric effect as order parameter in (NH4)2CuBr4·2H2O crystal

    Science.gov (United States)

    Tylczyński, Z.; Wiesner, M.; Trzaskowska, A.

    2016-11-01

    Temperature change of piezoelectric properties of (NH4)2CuBr4·2H2O crystal in the low-temperature ferroelastoelectric phase is studied. The macroscopic order parameter is proved to be the h36 component of the spontaneous piezoelectric tensor. The critical exponent related with the phase transition is α=0.60±0.05.

  15. Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

    Science.gov (United States)

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

    2015-12-01

    Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

  16. Effects of carbon nanotubes on liquid crystal order parameter and Freedericksz transition in electro-optic cells

    Science.gov (United States)

    Georgiev, Georgi; Gombos, Erin; McIntyre, Michael; Mattera, Michael; Gati, Peter; Cabrera, Yaniel; Cebe, Peggy

    2010-03-01

    We studied the effects of multiwalled carbon nanotubes (MWCTs) at low concentrations (0.01 wt %) on the Freedericksz transition of a 4-Cyano-4'-pentylbipenyl (5CB) liquid crystal using transmission ellipsometry. In addition, we calibrated the altitudinal angle of CNTs as a function of the electric field and directed the azimuthal angle which gave us complete control of the 3D orientation of the CNTs. Our results show that in the presence of CNTs the voltage and width for the Freedericksz transition are reduced by a factor of 1.8 as compared to the control electro-optic cell without CNTs. The shift in transition voltage correlates with increase in order parameter of the electro-optic cell as measured by our polarized UV/Vis absorption spectroscopy results. Research supported by: Assumption College Faculty Development Grant, funding for students' stipends, instrumentation and supplies, the NSF Polymers Program of the DME, grant (DMR-0602473) and NASA grant (NAG8-1167).

  17. Analysis of the variation of range parameters of thermal cameras

    Science.gov (United States)

    Bareła, Jarosław; Kastek, Mariusz; Firmanty, Krzysztof; Krupiński, Michał

    2016-10-01

    Measured range characteristics may vary considerably (up to several dozen percent) between different samples of the same camera type. The question is whether the manufacturing process somehow lacks repeatability or the commonly used measurement procedures themselves need improvement. The presented paper attempts to deal with the aforementioned question. The measurement method has been thoroughly analyzed as well as the measurement test bed. Camera components (such as detector and optics) have also been analyzed and their key parameters have been measured, including noise figures of the entire system. Laboratory measurements are the most precise method used to determine range parameters of a thermal camera. However, in order to obtain reliable results several important conditions have to be fulfilled. One must have the test equipment capable of measurement accuracy (uncertainty) significantly better than the magnitudes of measured quantities. The measurements must be performed in a controlled environment thus excluding the influence of varying environmental conditions. The personnel must be well-trained, experienced in testing the thermal imaging devices and familiar with the applied measurement procedures. The measurement data recorded for several dozen of cooled thermal cameras (from one of leading camera manufacturers) have been the basis of the presented analysis. The measurements were conducted in the accredited research laboratory of Institute of Optoelectronics (Military University of Technology).

  18. Sensitivity analysis on parameters and processes affecting vapor intrusion risk.

    Science.gov (United States)

    Picone, Sara; Valstar, Johan; van Gaans, Pauline; Grotenhuis, Tim; Rijnaarts, Huub

    2012-05-01

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion.

  19. Sensitivity analysis on parameters and processes affecting vapor intrusion risk

    KAUST Repository

    Picone, Sara

    2012-03-30

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion. © 2012 SETAC.

  20. Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Stephen B., E-mail: bmbsbc@bmb.leeds.ac.uk [Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom); Makris, George [Omega Mediation Hellas Ltd, Clinical and Pharma Consulting, 11525 N. Psychiko, Athens (Greece); Phillips, Simon E. V.; Thomas, Christopher D. [Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2006-11-01

    The crystallization and data collection of topoisomerase IV from S. aureus is described. Phasing by molecular replacement proved difficult owing to the presence of translational NCS and strategies used to overcome this are discussed. DNA topoisomerase IV removes undesirable topological features from DNA molecules in order to help maintain chromosome stability. Two constructs of 56 and 59 kDa spanning the DNA-cleavage domain of the A subunit of topoisomerase IV from Staphylococcus aureus (termed GrlA56 and GrlA59) have been crystallized. Crystals were grown at 291 K using the sitting-drop vapour-diffusion technique with PEG 3350 as a precipitant. Preliminary X-ray analysis revealed that GrlA56 crystals belong to space group P2{sub 1}, diffract to a resolution of 2.9 Å and possess unit-cell parameters a = 83.6, b = 171.5, c = 87.8 Å, β = 90.1°, while crystals of GrlA59 belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 41.5, b = 171.89, c = 87.9 Å. These crystals diffract to a resolution of 2.8 Å. This is the first report of the crystallization and preliminary X-ray analysis of the DNA-cleavage domain of a topoisomerase IV from a Gram-positive organism.

  1. Analysis of Electrical Coupling Parameters in Superconducting Cables

    CERN Document Server

    Bottura, L; Rosso, C

    2003-01-01

    The analysis of current distribution and redistribution in superconducting cables requires the knowledge of the electric coupling among strands, and in particular the interstrand resistance and inductance values. In practice both parameters can have wide variations in cables commonly used such as Rutherford cables for accelerators or Cable-in-Conduits for fusion and SMES magnets. In this paper we describe a model of a multi-stage twisted cable with arbitrary geometry that can be used to study the range of interstrand resistances and inductances that is associated with variations of geometry. These variations can be due to cabling or compaction effects. To describe the variations from the nominal geometry we have adopted a cable model that resembles to the physical process of cabling and compaction. The inductance calculation part of the model is validated by comparison to semi-analytical results, showing excellent accuracy and execution speed.

  2. Parameter Characterisation of Asphalt Mixtures for Visco-Elastoplastic Analysis

    Institute of Scientific and Technical Information of China (English)

    陆阳; 廖敬梅; 廖军

    2002-01-01

    Asphalt mixtures exhibit strong viscous properties under repetitive loads. This phenomenon can be simulated in creep and recovery tests. By applying the visco-elastoplastic model proposed, data recorded in the tests are interpreted. It is emphasised that applicability of the visco-elastoplastic model depends on the proper method of characterising parameters involved in the constitutive equations. Since two or more strain components of elasticity and viscosity coexist during the loading or unloading, a measuring system of two loggers is introduced to decouple these components. Test data are analysed in three steps as elastic, visco-elastic and visco-plastic evaluations, using the records collected at the moment of unloading, during the periods of recovery and creep respectively. Factors that may influence the accuracy of data analysis are also discussed.

  3. Finite element analysis on badminton racket design parameters

    CERN Document Server

    Nasruddin, Fakhrizal Azmy; Syahrom, Ardiyansyah; Abdul Kadir, Mohammed Rafiq; Omar, Abdul Hafidz; Öchsner, Andreas

    2016-01-01

    This work identifies the characteristics of racket design parameters that influence racket performance.  It presents the finite element analysis of several designs of badminton rackets and compares them to experimental results for validation. Designing a racket requires a comprehensive understanding of racket performance characteristics. Essentially, racket performance is related to the sweet spot, which is the spot on the racket head that produces the most power and control when it strikes a shuttlecock. Determining a coefficient of restitution can help to identify the sweet spot on a racket. By analyzing several head shape designs, it becomes apparent that isometric head shape rackets produce better coefficients of restitution compared to oval and round ones. It is recommended that the racket design consist of low string tension, stiffer racket shafts and bigger head size in order to produce higher shuttlecock speed.

  4. Analysis of Subclinical Hyperthyroidism Influence on Parameters of Bone Metabolism

    Directory of Open Access Journals (Sweden)

    I.V. Pankiv

    2015-04-01

    Full Text Available State of subclinical hypothyroidism can be considered as the optimal model for assessing the significance of thyroid stimulating hormone (TSH for bone tissue in clinical practice. Objective: to make a comparative analysis of the impact of subclinical hyperthyroidism of various origins on the performance of bone mineral density (BMD and bone metabolism parameters. Materials and methods. The study in an outpatient setting included 112 women with a diagnosis of subclinical hyperthyroidism and duration of menopause for at least 5 years. Among the examinees, endogenous subclinical hyperthyroidism has been detected in 78 women (group I, exogenous subclinical hyperthyroidism on the background of suppressive levothyroxine therapy (group II — in 34. The control group (group III included 20 women without thyroid dysfunction. Results. The study first conducted a comparative analysis of bone metabolism, BMD indicators, as well as parameters of phosphorus and calcium, blood lipids in women with subclinical hyperthyroidism of various origins. A positive correlation between markers of bone metabolism and free triiodothyronine (fT3 as hormones necessary for the development of the skeleton and to maintain its homeostasis indicates a physiological effect of parathyroid hormone and fT3 on bone tissue. It is shown that the bone metabolism and BMD depend not only on the content of TSH, but also on the causes of subclinical hyperthyroidism.Conclusions. In postmenopausal women with endogenous subclinical hyperthyroidism, there is a significant decline in BMD indices, more pronounced in the bones with the cortical structure. A negative correlation between markers of bone metabolism and TSH has been observed among all patients included in the study.

  5. Imaging and interferometric analysis of protein crystal growth

    Science.gov (United States)

    Raghunandan, Ranjini; Gupta, Anamika Sethia; Muralidhar, K.

    2008-04-01

    Protein crystals are grown under controlled temperature, concentration and vapor pressure conditions, usually by vapor diffusion, liquid-liquid diffusion and dialysis techniques. The present study examines the effects of protein concentration, drop size and reservoir height on the crystal growth of Hen Egg White Lysozyme (HEWL). Crystals are grown by the hanging drop vapor diffusion method using Modular VDX TM Plates. Due to the vapor pressure difference created between the protein drop and the reservoir, evaporation takes place till equilibrium is attained. Crystal formation takes place after a certain level of supersaturation is attained when the protein precipitates out in crystalline form. The observations revealed that the growth is faster for higher lysozyme concentration, smaller drop sizes and larger reservoir heights. The morphology of the crystals is viewed during the growth process using stereomicroscope. The number of crystals formed is the maximum for higher concentrations, drop sizes and reservoir heights. When the number of crystals formed is less, the size of the crystals is comparatively larger. The effect of evaporation of water vapor from the protein drop into the reservoir is studied using Mach-Zehnder interferometry. The recorded interferograms and shadowgraph images indicate the diffusion of condensed water into the reservoir. The radius of the drop is determined using the shadowgraph images of the growth process. The radius decreases with evaporation and the rate of decrease of radius is highest for higher protein concentrations, smaller drop sizes and larger reservoir heights.

  6. Volumetric and MGMT parameters in glioblastoma patients: Survival analysis

    Directory of Open Access Journals (Sweden)

    Iliadis Georgios

    2012-01-01

    Full Text Available Abstract Background In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre- and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O6-methylguanine methyltransferase related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods We prospectively analyzed 65 patients suffering from glioblastoma (GBM who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR sequences were used, acquired both pre- and postoperatively (pre-radiochemotherapy. The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligation-dependent Probe Amplification (MLPA, for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS (p = 0.023 and for preoperative necrosis on progression-free survival (PFS (p = 0.030. Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5% evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei was inversely associated with pre-operative tumor necrosis (p = 0.021. Conclusions Our findings implicate that volumetric parameters may have a significant role in

  7. [Measurement and analysis of anatomical parameter values in tree shrews].

    Science.gov (United States)

    Li, Bo; Zhang, Rong-Ping; Li, Jin-Tao; He, Bao-Li; Zhen, Hong; Wang, Li-Mei; Jiao, Jian-Lin

    2013-04-01

    Anatomical parameter values in tree shrews are major biological characteristic indicators in laboratory animals. Body size, bones and mammilla, organ weights, coefficient intestinal canal and other anatomical data were measured and analyzed in laboratory domesticated tree shrews (7 to 9 months of age). Measurement of 31 anatomical parameters showed that body height, width of the right ear, ileum and colon had significant differences between males and females (P<0.05). Highly significant differences were also found in body slanting length, chest depth, torso length, left and right forelimb length, right hind limb length, left and right ear length, left ear width, keel bone length, left and right tibia length, duodenum and jejunum (P<0.01). With body length as the dependent variable, and tail length, torso length, right and left forelimb length, and left and right hind limb length as independent variables for stepwise regression analysis, the regression equation for body length = 13.90 + tail length × 0.16. The results of 37 organs weights between female and male tree shrews showed very significant differences (P<0.01) for weight of heart, lungs, spleen, left and right kidney, bladder, left and right hippocampus, left submandibular gland, and left and right thyroid gland, as well as significant (P<0.05) differences in the small intestine, right submandibular gland, and left adrenal gland. The coefficient of heart, lung, stomach, bladder, small and large intestine, brain, right hippocampus, and left adrenal gland showed highly significant differences (P<0.01), while differences in the right kidney, left hippocampus, left submandibular gland, right adrenal gland, and left and right thyroid gland were significant (P<0.05). With animal weight as the dependent variable and indicators of heart, lung, liver, spleen, left and right kidney and brain as independent variables for stepwise regression analysis, the regression equation showed that weight = 62.73 + left kidney

  8. Analysis of crystallization data in the Protein Data Bank

    Energy Technology Data Exchange (ETDEWEB)

    Kirkwood, Jobie [University of York, York YO10 5DD (United Kingdom); Hargreaves, David [AstraZeneca, Darwin Building, Cambridge Science Park, Cambridge CB4 0WG (United Kingdom); O’Keefe, Simon [University of York, York YO10 5DD (United Kingdom); Wilson, Julie, E-mail: julie.wilson@york.ac.uk [University of York, York YO10 5DD (United Kingdom); University of York, York YO10 5DD (United Kingdom)

    2015-09-23

    In a large-scale study using data from the Protein Data Bank, some of the many reported findings regarding the crystallization of proteins were investigated. The Protein Data Bank (PDB) is the largest available repository of solved protein structures and contains a wealth of information on successful crystallization. Many centres have used their own experimental data to draw conclusions about proteins and the conditions in which they crystallize. Here, data from the PDB were used to reanalyse some of these results. The most successful crystallization reagents were identified, the link between solution pH and the isoelectric point of the protein was investigated and the possibility of predicting whether a protein will crystallize was explored.

  9. Co-crystals of the antiretroviral nevirapine: crystal structures, thermal analysis and dissolution behaviour

    OpenAIRE

    Aucamp, Marique Elizabeth; Engel, Emile; Liebenberg, Wilna; Stieger, Nicole; Caira, Mino R.; Susan A. Bourne

    2012-01-01

    Synthesis and physicochemical characterization of co-crystals of the antiretroviral drug nevirapine (NV) with the pharmaceutically acceptable co-formers saccharin, rac-tartaric acid, maleic acid, glutaric acid and salicylic acid are reported for the first time. The respective stoichiometric NV : co-former ratios are 2 : 1, 1 : 1, 1 : 1, 1 : 1 and 2 : 1. In the 1 : 1 co-crystals, the predicted R22(8) NV(amide)–carboxylic acid supramolecular synthon occurs, whereas in the 2 : 1 species, the co-...

  10. Performance analysis of pin fins with temperature dependent thermal parameters using the variation of parameters method

    Directory of Open Access Journals (Sweden)

    Cihat Arslantürk

    2016-08-01

    Full Text Available The performance of pin fins transferring heat by convection and radiation and having variable thermal conductivity, variable emissivity and variable heat transfer coefficient was investigated in the present paper. Nondimensionalizing the fin equation, the problem parameters which affect the fin performance were obtained. Dimensionless nonlinear fin equation was solved with the variation of parameters method, which is quite new in the solution of nonlinear heat transfer problems. The solution of variation of parameters method was compared with known analytical solutions and some numerical solution. The comparisons showed that the solutions are seen to be perfectly compatible. The effects of problem parameters were investigated on the heat transfer rate and fin efficiency and results were presented graphically.

  11. Expression, purification, crystallization and preliminary X-ray diffraction analysis of the DDX3 RNA helicase domain.

    Science.gov (United States)

    Rodamilans, Bernardo; Montoya, Guillermo

    2007-04-01

    DDX3 is a human RNA helicase that is involved in RNA processing and important human diseases. This enzyme belongs to the DEAD-box protein family, the members of which are characterized by the presence of nine conserved motifs including the Asp-Glu-Ala-Asp motif that defines the family. DDX3 has two distinct domains: an ATP-binding domain in the central region of the protein and a helicase domain in the carboxy-terminal region. The helicase domain of DDX3 was cloned and overexpressed in Escherichia coli. Crystallization experiments yielded crystals that were suitable for X-ray diffraction analysis. The final crystallization conditions were a reservoir solution consisting of 2 M ammonium sulfate, 0.1 M imidazole pH 6.4 plus 5 mM spermine tetrahydrochloride and a protein solution containing 10 mM HEPES, 500 mM ammonium sulfate pH 8.0. The crystals of the helicase domain belong to the monoclinic space group P2(1), with unit-cell parameters a = 43.85, b = 60.72, c = 88.39 A, alpha = gamma = 90, beta = 101.02 degrees , and contained three molecules per asymmetric unit. These crystals diffracted to a resolution limit of 2.2 A using synchrotron radiation at the European Synchrotron Radiation Facility (ESRF) and the Swiss Light Source (SLS).

  12. Growth and chemical analysis of bulk Nd 2- xCe xCuO y single crystals

    Science.gov (United States)

    Zhigunov, D. I.; Shiryaev, S. V.; Kurnevich, L. A.; Kalanda, N. A.; Kurochkin, L. A.; Barilo, S. N.; Vashuk, V. V.; Smakhtin, L. A.

    1999-03-01

    Single crystals of Nd 2- xCe xCuO y (0< x<0.17) from a family of the electron-type superconductors have been grown using platinum crucibles by the top seeded solution growth technique. The structural quality of the crystals was examined by X-ray diffraction. The FWHM of the Bragg reflections for the best samples varies from 8 to 20 angular seconds. Full neutron activation analysis was carried out to determine the chemical composition of the as-grown crystals. Small cation stoichiometry deviations from ideal (NdCe)/Cu ratio are found as well as Pt substitution on the copper sublattice at a level up to 2 at% exists depending on growth conditions. The results of thermogravimetric measurements and further annealing of samples show that the problem of an oxygen reduction of large Nd 2- xCe xCuO y crystals is closely connected with inhomogeneity of anion distribution in the lattice possibly caused by non-optimal parameters for the reduction process and the level of impurities contamination. A three step reduction process which produces superconductivity with Tc˜19 K in single crystals thicker than 1 mm has been developed.

  13. Crystallization and preliminary X-ray crystallographic analysis of polyphenol oxidase from Juglans regia (jrPPO1)

    Energy Technology Data Exchange (ETDEWEB)

    Zekiri, Florime; Bijelic, Aleksandar; Molitor, Christian; Rompel, Annette, E-mail: annette.rompel@univie.ac.at [Universität Wien, Althanstrasse 14, 1090 Wien (Austria)

    2014-05-28

    The crystallization and preliminary X-ray crystallographic analysis of a plant PPO exhibiting monophenolase activity from J. regia (jrPPO1) in its active form (Asp{sup 101}–Arg{sup 445}) are reported. Tyrosinase is a type 3 copper enzyme that catalyzes the ortho-hydroxylation of monophenols to diphenols as well as their subsequent oxidation to quinones, which are precursors for the biosynthesis of melanins. The first plant tyrosinase from walnut leaves (Juglans regia) was purified to homogeneity and crystallized. During the purification, two forms of the enzyme differing only in their C-termini [jrPPO1(Asp{sup 101}–Pro{sup 444}) and jrPPO1(Asp{sup 101}–Arg{sup 445})] were obtained. The most abundant form jrPPO1(Asp{sup 101}–Arg{sup 445}), as described in Zekiri et al. [Phytochemistry (2014 ▶), 101, 5–15], was crystallized, resulting in crystals that belonged to space group C121, with unit-cell parameters a = 115.56, b = 91.90, c = 86.87 Å, α = 90, β = 130.186, γ = 90°, and diffracted to 2.39 Å resolution. Crystals were only obtained from solutions containing at least 30% polyethylene glycol 5000 monomethyl ether in a close-to-neutral pH range.

  14. Crystallization and preliminary X-ray diffraction analysis of an anti-H(O) lectin from Lotus tetragonolobus seeds

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Frederico Bruno Mendes Batista; Martil, Daiana Evelin [Programa de Pós-graduação em Biofísica Molecular, Departamento de Física, UNESP, São José do Rio Preto, SP 15054-000 (Brazil); Cavada, Benildo Sousa [BioMol-Lab UFC, Caixa Postal 6043, 60.455-970, Fortaleza-CE (Brazil); Azevedo, Walter Filgueira Jr de, E-mail: walter.junior@pucrs.br [Faculdade de Biociências-PUCRS, Av. Ipiranga 6681, Porto Alegre-RS, CEP 90619-900 (Brazil); Programa de Pós-graduação em Biofísica Molecular, Departamento de Física, UNESP, São José do Rio Preto, SP 15054-000 (Brazil)

    2006-07-01

    The seed lectin from Lotus tetragonolobus (LTA) has been crystallized. The best crystals grew over several days and were obtained using the vapour-diffusion method at a constant temperature of 293 K. The seed lectin from Lotus tetragonolobus (LTA) has been crystallized. The best crystals grew over several days and were obtained using the vapour-diffusion method at a constant temperature of 293 K. A complete structural data set was collected at 2.00 Å resolution using a synchrotron-radiation source. LTA crystals were found to be monoclinic, belonging to space group P2{sub 1}, with unit-cell parameters a = 68.89, b = 65.83, c = 102.53 Å, α = γ = 90, β = 92°. Molecular replacement yielded a solution with a correlation coefficient and R factor of 34.4 and 51.6%, respectively. Preliminary analysis of the molecular-replacement solution indicates a new quaternary association in the LTA structure. Crystallographic refinement is under way.

  15. Theoretical investigations of the spin-Hamiltonian parameters and local structural distortion of Fe(3+): ZnAl2O4 crystals.

    Science.gov (United States)

    Yang, Zi-Yuan

    2014-10-15

    The relations between the spin-Hamiltonian (SH) parameters and the structural parameters of the Fe(3+) ions in Fe(3+): ZnAl2O4 crystals have been established by means of the microscopic spin Hamiltonian theory and the superposition model (SPM). On the basis of this, the local structure distortion, the second-order zero-field splitting (ZFS) parameter D, the fourth-order ZFS parameter (a-F), and the Zeeman g-factors g factors: g//, g⊥, and Δg(=g//-g⊥) for Fe(3+) ions in Fe(3+): ZnAl2O4 crystals, for the first time taking into account the electronic magnetic interactions, i.e. the spin-spin (SS), the spin-other-orbit (SOO), and the orbit-orbit (OO) interactions, besides the well-known spin-orbit (SO) interaction, are theoretically investigated using complete diagonalization method (CDM). This investigation reveals that the local structure distortion effect plays an important role in explaining the spectroscopic properties of Fe(3+) ions in Fe(3+): ZnAl2O4 crystals. The theoretical second-order ZFS parameter D, the fourth-order ZFS parameter (a-F), and the Zeeman g-factors: g//, g⊥, and Δg of the ground state for Fe(3+) ion in Fe(3+): ZnAl2O4 crystals yield a good agreement with experiment findings by taking into account the lattice distortions: ΔR=0.0191nm and Δθ=0.076°. In conclusion, our research shows that there is a slight local structure distortion for Fe(3+) ions in Fe(3+): ZnAl2O4 crystals, but the site of Fe(3+) still retains D3d symmetry. On the other hand, it is found for Fe(3+) ions in Fe(3+): ZnAl2O4 crystals that the SO mechanism is the most important one, whereas the contributions to the SH parameters from other four mechanisms, including the SS, SOO, OO, and SO∼SS∼SOO∼OO mechanisms are not appreciable, especially for the ZFS parameter D.

  16. Statistical analysis of the operating parameters which affect cupola emissions

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.W.; Draper, A.B.

    1977-12-01

    A sampling program was undertaken to determine the operating parameters which affected air pollution emission from gray iron foundry cupolas. The experimental design utilized the analysis of variance routine. Four independent variables were selected for examination on the basis of previous work reported in the literature. These were: (1) blast rate; (2) iron-coke ratio; (3) blast temperature; and (4) cupola size. The last variable was chosen since it most directly affects melt rate. Emissions from cupolas for which concern has been expressed are particle matter and carbon monoxide. The dependent variables were, therefore, particle loading, particle size distribution, and carbon monoxide concentration. Seven production foundries were visited and samples taken under conditions prescribed by the experimental plan. The data obtained from these tests were analyzed using the analysis of variance and other statistical techniques where applicable. The results indicated that blast rate, blast temperature, and cupola size affected particle emissions and the latter two also affected the particle size distribution. The particle size information was also unique in that it showed a consistent particle size distribution at all seven foundaries with a sizable fraction of the particles less than 1.0 micrometers in diameter.

  17. Analysis of submicron-sized niflumic acid crystals prepared by electrospray crystallization

    NARCIS (Netherlands)

    Ambrus, R.; Radacsi, N.; Szunyogh, T.; Heijden, A.E.D.M. van der; Horst, J.H. ter; Szabó-Révész, P.

    2013-01-01

    Interest in submicron-sized drug particles has emerged from both laboratory and industrial perspectives in the last decade. Production of crystals in the nano size scale offers a novel way to particles for drug formulation solving formulation problems of drugs with low solubility in class II of the

  18. Analysis of hydration parameter for sugars determined from viscosity and its relationship with solution parameters.

    Science.gov (United States)

    Sato, Yukinori; Miyawaki, Osato

    2016-01-01

    The hydration parameter h was obtained from the viscosity B-coefficients and the partial molar volume of solute, V2, for various sugars and urea in aqueous solutions. The parameter h showed a good correlation with the parameter α, determined from the activity coefficient of water, representing the solute-solvent interaction. The parameter h also showed a good correlation with the number of equatorial-OH groups (e-OH) for sugars, suggesting that the sugar molecules with the higher e-OH fit more to the water-structure. From the temperature dependence of the parameter h (dh/dT), the negative dh/dT for sugars suggested their water-structure making activity while the positive dh/dT for urea corresponded to its structure breaking effect. From the Arrhenius plot, the activation energy for h, Ea, was determined to be as low as 10 kJ/mol for disaccharides suggesting the stable hydration structure. The Ea increased with a decrease in molecular weight for sugars.

  19. Descriptive quantitative analysis of hallux abductovalgus transverse plane radiographic parameters.

    Science.gov (United States)

    Meyr, Andrew J; Myers, Adam; Pontious, Jane

    2014-01-01

    Although the transverse plane radiographic parameters of the first intermetatarsal angle (IMA), hallux abductus angle (HAA), and the metatarsal-sesamoid position (MSP) form the basis of preoperative procedure selection and postoperative surgical evaluation of the hallux abductovalgus deformity, the so-called normal values of these measurements have not been well established. The objectives of the present study were to (1) evaluate the descriptive statistics of the first IMA, HAA, and MSP from a large patient population and (2) to determine an objective basis for defining "normal" versus "abnormal" measurements. Anteroposterior foot radiographs from 373 consecutive patients without a history of previous foot and ankle surgery and/or trauma were evaluated for the measurements of the first IMA, HAA, and MSP. The results revealed a mean measurement of 9.93°, 17.59°, and position 3.63 for the first IMA, HAA, and MSP, respectively. An advanced descriptive analysis demonstrated data characteristics of both parametric and nonparametric distributions. Furthermore, clear differentiations in deformity progression were appreciated when the variables were graphically depicted against each other. This could represent a quantitative basis for defining "normal" versus "abnormal" values. From the results of the present study, we have concluded that these radiographic parameters can be more conservatively reported and analyzed using nonparametric descriptive and comparative statistics within medical studies and that the combination of a first IMA, HAA, and MSP at or greater than approximately 10°, 18°, and position 4, respectively, appears to be an objective "tipping point" in terms of deformity progression and might represent an upper limit of acceptable in terms of surgical deformity correction.

  20. Theoretical research of the spin-Hamiltonian parameters for two rhombic W5+ centers in KTiOPO4 (KTP) crystal through a two-mechanism model

    Science.gov (United States)

    Mei, Yang; Chen, Bo-Wei; Wei, Chen-Fu; Zheng, Wen-Chen

    2016-09-01

    The high-order perturbation formulas based on the two-mechanism model are employed to calculate the spin-Hamiltonian parameters (g factors gi and hyperfine structure constants Ai, where i=x, y, z) for two approximately rhombic W5+ centers in KTiOPO4 (KTP) crystal. In the model, both the widely-applied crystal-field (CF) mechanism concerning the interactions of CF excited states with the ground state and the generally-neglected charge-transfer (CT) mechanism concerning the interactions of CT excited states with the ground state are included. The calculated results agree with the experimental values, and the signs of constants Ai are suggested. The calculations indicate that (i) for the high valence state dn ions in crystals, the contributions to spin-Hamiltonian parameters should take into account both the CF and CT mechanisms and (ii) the large g-shifts |Δgi | (=|gi-ge |, where ge≈ 2.0023) for W5+ centers in crystals are due to the large spin-orbit parameter of free W5+ ion.

  1. Remote sensing of ice crystal asymmetry parameter using multi-directional polarization measurements – Part 1: Methodology and evaluation with simulated measurements

    Directory of Open Access Journals (Sweden)

    P. Yang

    2012-10-01

    Full Text Available We present a new remote sensing technique to infer the average asymmetry parameter of ice crystals near cloud top from multi-directional polarization measurements. The method is based on previous findings that (a complex aggregates of hexagonal crystals generally have scattering phase matrices resembling those of their components; and (b scattering phase matrices systematically vary with aspect ratios of crystals and their degree of microscale surface roughness. Ice cloud asymmetry parameters are inferred from multi-directional polarized reflectance measurements by searching for the closest fit in a look-up table of simulated polarized reflectances computed for cloud layers that contain individual, randomly oriented hexagonal columns and plates with varying aspect ratios and roughness values. The asymmetry parameter of the hexagonal particle that leads to the best fit with the measurements is considered the retrieved value. For clouds with optical thickness less than 5, the cloud optical thickness must be retrieved simultaneously with the asymmetry parameter, while for optically thicker clouds the asymmetry parameter retrieval is independent of cloud optical thickness. Evaluation of the technique using simulated measurements based on the optical properties of a number of complex particles and their mixtures shows that the ice crystal asymmetry parameters are generally retrieved to within 5%, or about 0.04 in absolute terms. The retrieval scheme is largely independent of calibration errors, range and sampling density of scattering angles and random noise in the measurements. The approach can be applied to measurements of past, current and future airborne and satellite instruments that measure multi-directional polarized reflectances of ice-topped clouds.

  2. Remote sensing of ice crystal asymmetry parameter using multi-directional polarization measurements – Part 1: Methodology and evaluation with simulated measurements

    Directory of Open Access Journals (Sweden)

    B. van Diedenhoven

    2012-06-01

    Full Text Available We present a new remote sensing technique to infer the average asymmetry parameter of ice crystals near cloud top from multi-directional polarization measurements. The method is based on previous findings that (a complex aggregates of hexagonal crystals generally have scattering phase matrices resembling those of their components and (b scattering phase matrices systematically vary with aspect ratios of crystals and their degree of microscale surface roughness. Ice cloud asymmetry parameters are inferred from multi-directional polarized reflectance measurements by searching for the closest fit in a look-up table of simulated polarized reflectances computed for cloud layers that contain individual hexagonal columns and plates with varying aspect ratios and roughness values. The asymmetry parameter of the hexagonal particle that leads to the best fit with the measurements is considered the retrieved value. For clouds with optical thickness less than 5, the cloud optical thickness must be retrieved simultaneously with the asymmetry parameter, while for optically thicker clouds the asymmetry parameter retrieval is independent of cloud optical thickness. Evaluation of the technique using simulated measurements based on the optical properties of a number of complex particles and their mixtures shows that the ice crystal asymmetry parameters are generally retrieved to within 5%, or about 0.04 in absolute terms. The retrieval scheme is largely independent of calibration errors, range and sampling density of scattering angles and random noise in the measurements. The approach can be readily applied to measurements of past, current and future airborne and satellite instruments that measure multi-directional polarized reflectances of ice-topped clouds.

  3. UV optical absorption spectra analysis of beryl crystals from Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Isotani, Sadao, E-mail: sisotani@if.usp.b [Instituto de Fisica da Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo (Brazil); Regina Blak, Ana; Watanabe, Shigueo [Instituto de Fisica da Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo (Brazil)

    2010-03-15

    The spectral decomposition analysis was applied to the optical absorption spectra of green and colorless beryl crystals from the Brazilian Eastern Pegmatitic province in the natural state, submitted to heat treatment and irradiated with UV light. The attributions of the lines were made taking into account highly accurate quantum mechanical calculations. The deconvolution of the green beryl spectra revealed four lines, two of them around 12,000 cm{sup -1} (1.5 eV) and two of them around 34,000 cm{sup -1} (4.2 eV) attributed to Fe{sup 2+} and Fe{sup 3+}, respectively. The deconvolution of the colorless beryl spectra without any treatment, after heating and for the same heat treatment followed by UV light irradiation revealed five lines. The analysis of ratio relations showed that the lines at 36,400 cm{sup -1} (4.5 eV) and 41,400 cm{sup -1} (5.1 eV) belongs to a single defect attributed to a silicon dangling bond defect (=Si:). Discussions and comparison with reported defects in quartz have supported the allocation of the lines at 61,000 cm{sup -1} (7.6 eV) and 43,800 cm{sup -1} (5.4 eV) to diamagnetic oxygen vacancy defect (ident toSi-Siident to) and unrelaxed (ident toSi...Siident to) defect, respectively. Finally, the line at 39,100 cm{sup -1} (4.8 eV), quite polarized along the c-axis, was attributed to a (Fe{sup 2+}OH{sup -}) defect in the structural channels.

  4. Crystallization and preliminary X-ray analysis of Streptococcus mutans dextran glucosidase

    Energy Technology Data Exchange (ETDEWEB)

    Saburi, Wataru; Hondoh, Hironori, E-mail: hondoh@abs.agr.hokudai.ac.jp [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan); Unno, Hideaki [Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521 (Japan); Okuyama, Masayuki; Mori, Haruhide [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan); Nakada, Toshitaka [Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Matsuura, Yoshiki [Institute for Protein Research, Osaka University, Suita, Osaka 565-0871 (Japan); Kimura, Atsuo [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan)

    2007-09-01

    Dextran glucosidase from S. mutans was crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.2 Å resolution. Dextran glucosidase from Streptococcus mutans is an exo-hydrolase that acts on the nonreducing terminal α-1,6-glucosidic linkage of oligosaccharides and dextran with a high degree of transglucosylation. Based on amino-acid sequence similarity, this enzyme is classified into glycoside hydrolase family 13. Recombinant dextran glucosidase was purified and crystallized by the hanging-drop vapour-diffusion technique using polyethylene glycol 6000 as a precipitant. The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 72.72, b = 86.47, c = 104.30 Å. A native data set was collected to 2.2 Å resolution from a single crystal.

  5. Crystallization and preliminary crystallographic analysis of endo-1,4-beta-xylanase I from Aspergillus niger

    NARCIS (Netherlands)

    Krengel, U; Rozeboom, HJ; Kalk, KH; Dijkstra, BW

    1996-01-01

    A family G xylanase from Aspergillus niger has been crystallized using the vapor-diffusion method. Several crystal forms could be obtained using various sodium salts as precipitants. Three of the crystal forms belong to space groups P2(1), P2(1)2(1)2(1) and P4(3) and have cell parameters of approxim

  6. Crystal Plasticity Analysis on Compressive Loading of Magnesium with Suppression of Twinning

    Science.gov (United States)

    Mayama, Tsuyoshi; Ohashi, Tetsuya; Higashida, Kenji; Kawamura, Yoshihito

    The compressive loading behavior of single crystals and bicrystals of magnesium without consideration of deformation twinning has been investigated by crystal plasticity finite element analysis with the aim of fundamental understanding of kink band formation in magnesium alloys with long period stacking ordered structure (LPSO) phase. The basal plane of the single crystal model is set to be parallel to the compressive direction. The result of the compressive loading analysis of single crystals indicates the significant influence of suppression of twinning on the activation of nonbasal slip systems and stress-strain behavior. The compressive analysis of symmetric bicrystal is also performed to clarify the influence of the angle between basal plane and the loading axis. The influence of the introduction of grain boundary and the slight change of crystal orientation is discussed in terms of activated deformation modes.

  7. Applying shot boundary detection for automated crystal growth analysis during in situ transmission electron microscope experiments

    Energy Technology Data Exchange (ETDEWEB)

    Moeglein, W. A.; Griswold, R.; Mehdi, B. L.; Browning, N. D.; Teuton, J.

    2017-01-03

    In-situ (scanning) transmission electron microscopy (S/TEM) is being developed for numerous applications in the study of nucleation and growth under electrochemical driving forces. For this type of experiment, one of the key parameters is to identify when nucleation initiates. Typically the process of identifying the moment that crystals begin to form is a manual process requiring the user to perform an observation and respond accordingly (adjust focus, magnification, translate the stage etc.). However, as the speed of the cameras being used to perform these observations increases, the ability of a user to “catch” the important initial stage of nucleation decreases (there is more information that is available in the first few milliseconds of the process). Here we show that video shot boundary detection (SBD) can automatically detect frames where a change in the image occurs. We show that this method can be applied to quickly and accurately identify points of change during crystal growth. This technique allows for automated segmentation of a digital stream for further analysis and the assignment of arbitrary time stamps for the initiation of processes that are independent of the user’s ability to observe and react.

  8. Rapid X-ray crystal structure analysis in few second measurements using microstrip gas chamber

    CERN Document Server

    Ochi, A; Tanimori, T; Ohashi, Y; Toyokawa, H; Nishi, Y; Nishi, Y; Nagayoshi, T; Koishi, S

    2001-01-01

    X-ray crystal structure analysis using microstrip gas chamber was successfully carried out in a measurement time within a few seconds. The continuous rotation photograph method, in which most of the diffraction peaks can be obtained within one continuous rotation of the sample crystal (without stopping or oscillation), was applied for this measurement. As an example, the structure of a single crystal of ammonium bitartrate (r=1 mm, spherical) was measured. Diffraction spots from the sample, which were sufficient to obtain crystal structure, were successfully obtained by taking only 2 s measurements with a commercially available laboratory X-ray source.

  9. Purification, crystallization and preliminary X-ray analysis of struthiocalcin 1 from ostrich (Struthio camelus) eggshell

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Grajeda, Juan Pablo [Unidad de Proteómica Médica, Instituto Nacional de Medicina Genómica, Mexico City (Mexico); Marín-García, Liliana [Instituto de Química, Universidad Nacional Autónoma de México (Mexico); Stojanoff, Vivian [Brookhaven National Laboratories, NSLS, Upton, New York (United States); Moreno, Abel, E-mail: carcamo@servidor.unam.mx [Instituto de Química, Universidad Nacional Autónoma de México (Mexico); Unidad de Proteómica Médica, Instituto Nacional de Medicina Genómica, Mexico City (Mexico)

    2007-11-01

    The purification, crystallization and preliminary X-ray diffraction data of the protein struthiocalcin 1 isolated from ostrich eggshell are reported. The purification, crystallization and preliminary X-ray analysis of struthiocalcin 1 (SCA-1), a protein obtained from the intramineral part of ostrich (Struthio camelus) eggshell, is reported.

  10. Analysis of CZT crystals and detectors grown in Russia and the Ukraine by high-pressure Bridgman methods

    Energy Technology Data Exchange (ETDEWEB)

    H. Hermon; M. Schieber; R. B. James; E. Y. Lee; N. Yang; A. J. Antolak; D. H. Morse; C. Hackett; E. Tarver; N. N. P. Kolesnikov; Yu N. Ivanov; V. Komar; M. S. Goorsky; H. Yoon

    2000-01-10

    Sandia National Laboratories (SNL) is leading an effort to evaluate vertical high pressure Bridgman (VHPB) Cd{sub 1-x}Zn{sub x}Te (CZT) crystals grown in the former Soviet Union (FSU) (Ukraine and Russia), in order to study the parameters limiting the crystal quality and the radiation detector performance. The stoichiometry of the CZT crystals, with 0.04 < x < 0.25, has been determined by methods such as proton-induced X-ray emission (PIXE), X-ray diffraction (XRD), microprobe analysis and laser ablation ICP mass spectroscopy (LA-ICP/MS). Other methods such as triaxial double crystal x-ray diffraction (TADXRD), infrared transmission spectroscopy (IR), atomic force microscopy (AFM), thermoelectric emission spectroscopy (TEES) and laser induced transient charge technique (TCT) were also used to evaluate the material properties. The authors have measured the zinc distribution in a CZT ingot along the axial direction and also its homogeneity. The (Cd+Zn)/Te average ratio measured on the Ukraine crystals was 1.2, compared to the ratio of 0.9-1.06 on the Russian ingots. The IR transmission showed highly decorated grain boundaries with precipitates and hollow bubbles. Microprobe elemental analysis and LA-ICP/MS showed carbon precipitates in the CZT bulk and carbon deposits along grain boundaries. The higher concentration of impurities and the imperfect crystallinity lead to shorter electron and hole lifetimes in the range of 0.5--2 {micro}s and 0.1 {micro}s respectively, compared to 3--20 {micro}s and 1--7 {micro}s measured on US spectrometer grade CZT detectors. These results are consistent with the lower resistivity and worse crystalline perfection of these crystals, compared to US grown CZT. However, recently grown CZT from FSU exhibited better detector performance and good response to alpha particles.

  11. Thermal-capillary analysis of Czochralski and liquid encapsulated Czochralski crystal growth. II - Processing strategies

    Science.gov (United States)

    Derby, J. J.; Brown, R. A.

    1986-01-01

    The pseudosteady-state heat transfer model developed in a previous paper is augmented with constraints for constant crystal radius and melt/solid interface deflection. Combinations of growth rate, and crucible and bottom-heater temperatures are tested as processing parameters for satisfying the constrained thermal-capillary problem over a range of melt volumes corresponding to the sequence occuring during the batchwise Czochralski growth of a small-diameter silicon crystal. The applicability of each processing strategy is judged by the range of existence of the solution, in terms of melt volume and the values of the axial and radial temperature gradients in the crystal.

  12. Crystallization and preliminary X-ray crystallographic analysis of human geranylgeranyl pyrophosphate synthase

    Institute of Scientific and Technical Information of China (English)

    CHEN Yushu; LI Xiaofeng; LOU Zhiyong; WANG Weina; PANG Hai; RAO Zihe

    2006-01-01

    Human geranylgeranyl pyrophosphate synthase (GGPS) is an enzyme that catalyzes the synthesis of geranylgeranyl py rophosphate (GGPP) from farnesyldiphosphate and isopentenyldiphosphate. Recombinant human GGPS was crystallized by the hanging-drop vapor diffusion method. Crystals were grown at 18℃ using PEG 4000 as precipitant. Diffraction data were obtained to a resolution of 2.8 (A) from a single frozen crystal belonging to space group PI, with unit-cell parameters: α = 68.9 (A), b = 107.7 (A), c = 137.4 (A),α=99.6°, β=97.6°, γ=97.8°.

  13. Mechanical and morphological investigation of virgin polyethylene and silver nanoparticle-loaded nanocomposites film: comprehensive analysis of kinetic models for non-isothermal crystallization

    Indian Academy of Sciences (India)

    RAJESH KUMAR SAHOO; BISHNU PRASAD PANDA; SANJAY KUMAR NAYAK; SMITA MOHANTY

    2017-04-01

    This research was accomplished to examine the mechanical, morphological and crystallization kinetics study of polyethylene/silver nanoparticles (Ag-NPs) nanocomposite films. In this research, low-density polyethylene (LDPE) nanocomposite films were prepared containing Ag-NPs using maleic-anhydride-grafted low-density polyethylene (LDPE-g-MAH) as a compatibilizer by the melt mixing process. From mechanical property evaluation, it is revealed that the LDPE/LDPE-g-MAH/Ag-NPs nanocomposite films showed decreased tensile strength as compared with virgin LDPE matrix. Thermal characteristics of the prepared virgin LDPE and its nanocomposite films were studied by differential scanning calorimetry (DSC). Comprehensive analysis of different kinetic modelssuch as the Avrami and Mo model on non-isothermal crystallization kinetics was performed in order to correlate the rate of crystallization and its various kinetic parameters. Further, the macrokinetic equation as proposed by Malkinhas been applied to describe the kinetics of crystallization in the light of the Avrami equation. Concerning virgin LDPE and Ag-NP-reinforced LDPE, the former shows primary crystallization, whereas the later exhibits both primaryand secondary crystallization with varying Avrami exponents. Kinetic parameters are recognized, and confirm the influence of Ag-NPs on crystallization kinetics. X-ray diffraction spectroscopy and transmission electron microscopicanalysis of the nanocomposite films were conducted to verify the dispersion of inorganic filler particles in the resulting hybrids.

  14. Purification, crystallization and preliminary crystallographic analysis of KatB, a manganese catalase from Anabaena PCC 7120.

    Science.gov (United States)

    Bihani, Subhash Chandra; Chakravarty, Dhiman; Ballal, Anand

    2013-11-01

    Catalases are enzymes that play an important role in the detoxification of hydrogen peroxide (H2O2) in aerobic organisms. Among catalases, haem-containing catalases are ubiquitously distributed and their enzymatic mechanism is very well understood. On the other hand, manganese catalases that contain a bimanganese core in the active site have been less well characterized and their mode of action is not fully understood. The genome of Anabaena PCC 7120 does not show the presence of a haem catalase-like gene; instead, two ORFs encoding manganese catalases (Mn-catalases) are present. Here, the crystallization and preliminary X-ray crystallographic analysis of KatB, one of the two Mn-catalases from Anabaena, are reported. KatB was crystallized using the hanging-drop vapour-diffusion method with PEG 400 as a precipitant and calcium acetate as an additive. Diffraction data were collected in-house on an Agilent SuperNova system using a microfocus sealed-tube X-ray source. The crystal diffracted to 2.2 Å resolution at 100 K. The tetragonal crystal belonged to space group P4(1)2(1)2 (or enantiomer), with unit-cell parameters a = b = 101.87, c = 138.86 Å. Preliminary X-ray diffraction analysis using the Matthews coefficient and self-rotation function suggests the presence of a trimer in the asymmetric unit.

  15. Design & Analysis of Optical Lenses by using 2D Photonic Crystals for Sub-wavelength Focusing

    Directory of Open Access Journals (Sweden)

    Rajib Ahmed

    2013-01-01

    Full Text Available 2D Photonic lenses (Convex-Convex, Convex-Plane, Plane-Convex, Concave-Concave, Concave-plane, and PlaneConcave have been designed, simulated and optimized for optical communication using FDTD method. The effect of Crystal structures (Rectangular, Hexagonal, Face centered Cubic (FCC, Body centered Cubic (BCC, variation lattice constant (Λ, hole radius(r, reflective index (n, is demonstrated to get optimized parameters. Finally, with optimized parameters the effect of variation of lens radius on focal lengths and Electrical Field Intensity (Ey is analyzed. Like optical lens, the focal length of photonic lens is also increased with lens radii, has dependency on optical axis. Moreover, with optimized parameters, ConcaveConcave lens have been found as an optimal photonic lens that show sub-wavelength focusing with spatial resolutions-9.22439μm (Rectangular crystal, 7.379512μm (Hexagonal Crystal, 7.840732μm (FCC, BCC.

  16. Sensitivity analysis on parameter changes in underground mine ventilation systems

    Institute of Scientific and Technical Information of China (English)

    LI Gary; KOCSIS Charles; HARDCASTLE Steve

    2011-01-01

    A more efficient mine ventilation system,the ventilation-on-demand (VOD) system,has been proposed and tested in Canadian mines recently.In order to supply the required air volumes to the production areas of a mine,operators need to know the cause and effect of any changes requested from the VOD system.The sensitivity analysis is developed through generating a cause and effect matrix of sensitivity factors on given parameter changes in a ventilation system.This new utility,which was incorporated in the 3D-CANVENT mine ventilation simulator,is able to predict the airflow distributions in a ventilation network when underground conditions and ventilation controls are changed.For a primary ventilation system,the software can determine the optimal operating speed of the main fans to satisfy the airflow requirements in underground workings without necessarily using booster fans and regulators locally.An optimized fan operating speed time-table would assure variable demand-based fresh air delivery to the production areas effectively,while generating significant savings in energy consumption and operating cost.

  17. Meteorologic parameters analysis above Dome C made with ECMWF data

    CERN Document Server

    Geissler, Kryno K

    2006-01-01

    In this paper we present the characterization of all the principal meteorological parameters (wind speed and direction, pressure, absolute and potential temperature) extended over 25 km from the ground and over two years (2003 and 2004) above the Antarctic site of Dome C. The data set is composed by 'analyses' provided by the General Circulation Model (GCM) of the European Center for Medium Weather Forecasts (ECMWF) and they are part of the catalog MARS. A monthly and seasonal (summer and winter time) statistical analysis of the results is presented. The Richardson number is calculated for each month of the year over 25 km to study the stability/instability of the atmosphere. This permits us to trace a map indicating where and when the optical turbulence has the highest probability to be triggered on the whole troposphere, tropopause and stratosphere. We finally try to predict the best expected isoplanatic angle and wavefront coherence time employing the Richardson number maps, the wind speed profiles and sim...

  18. Hansen solubility parameter analysis on the dispersion of zirconia nanocrystals.

    Science.gov (United States)

    Wang, Sho-Hsun; Liu, Jia-Hong; Pai, Chin-Tung; Chen, Chien-Wei; Chung, Pao-Tang; Chiang, Anthony Shiaw-Tseh; Chang, Shinn-Jen

    2013-10-01

    Nanoparticle dispersible in a broad range of solvents is desirable when preparing an organic/inorganic nanocomposite. In this report, the dispersion behavior of carboxylate-grafted zirconia nanoparticle in 25 solvents covering a wide range of polarity was analyzed based on their Hansen solubility parameters (HSP). Particles grafted with alkyl-chain longer than four carbons could only be dispersed in non-polar solvents, while that grafted with acetic acid was dispersible in polar ones. However, particle modified with methacrylic acid (MA) was compatible with both types of solvents, which was rather unexpected. Further NMR analysis showed that the carboxylate-grafted samples contained a trace amount of triethanolamine (TEA) due to the particular ZrO2 synthesis process employed. The combination of the hydrophilic TEA ligand with the short hydrophobic tail of methacrylate broadened the range of compatible solvents from benzene to methanol. Such an extended solvent compatibility was observed previously only for nanoparticles covered with large polymer surfactants having both hydrophilic and hydrophobic groups. Achieving this with two small molecules having separate functional groups is crucial when one needs to maximize the inorganic content in a composite.

  19. Using Entropy for Parameter Analysis of Evolutionary Algorithms

    Science.gov (United States)

    Smit, Selmar K.; Eiben, Agoston E.

    Evolutionary algorithms (EA) form a rich class of stochastic search methods that share the basic principles of incrementally improving the quality of a set of candidate solutions by means of variation and selection (Eiben and Smith 2003, De Jong 2006). Such variation and selection operators often require parameters to be specified. Finding a good set of parameter values is a nontrivial problem in itself. Furthermore, some EA parameters are more relevant than others in the sense that choosing different values for them affects EA performance more than for the other parameters. In this chapter we explain the notion of entropy and discuss how entropy can disclose important information about EA parameters, in particular, about their relevance. We describe an algorithm that is able to estimate the entropy of EA parameters and we present a case study, based on extensive experimentation, to demonstrate the usefulness of this approach and some interesting insights that are gained.

  20. Crystallization and preliminary X-ray crystallographic analysis of yeast prion protein Ure2p with shortened N-terminal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An orthorhombic crystal form of a recombinant yeast prion protein with shortened N-terminal, 90Ure2p, has been obtained. Crystals were grown by the vapordiffusion technique against a mother liquor containing imidazole. Crystals belong to the primitive orthorhombic lattice with the cell parameters a = 54.5 ?, b = 74.7 ?, c = 131.0 ?. The crystals diffract to beyond 3.0 ? resolution at a synchrotron beamline.

  1. Crysalis: an integrated server for computational analysis and design of protein crystallization.

    Science.gov (United States)

    Wang, Huilin; Feng, Liubin; Zhang, Ziding; Webb, Geoffrey I; Lin, Donghai; Song, Jiangning

    2016-02-24

    The failure of multi-step experimental procedures to yield diffraction-quality crystals is a major bottleneck in protein structure determination. Accordingly, several bioinformatics methods have been successfully developed and employed to select crystallizable proteins. Unfortunately, the majority of existing in silico methods only allow the prediction of crystallization propensity, seldom enabling computational design of protein mutants that can be targeted for enhancing protein crystallizability. Here, we present Crysalis, an integrated crystallization analysis tool that builds on support-vector regression (SVR) models to facilitate computational protein crystallization prediction, analysis, and design. More specifically, the functionality of this new tool includes: (1) rapid selection of target crystallizable proteins at the proteome level, (2) identification of site non-optimality for protein crystallization and systematic analysis of all potential single-point mutations that might enhance protein crystallization propensity, and (3) annotation of target protein based on predicted structural properties. We applied the design mode of Crysalis to identify site non-optimality for protein crystallization on a proteome-scale, focusing on proteins currently classified as non-crystallizable. Our results revealed that site non-optimality is based on biases related to residues, predicted structures, physicochemical properties, and sequence loci, which provides in-depth understanding of the features influencing protein crystallization. Crysalis is freely available at http://nmrcen.xmu.edu.cn/crysalis/.

  2. Remote sensing of ice crystal asymmetry parameter using multi-directional polarization measurements – Part 2: Application to the Research Scanning Polarimeter

    Directory of Open Access Journals (Sweden)

    B. van Diedenhoven

    2013-03-01

    Full Text Available A new method to retrieve ice cloud asymmetry parameters from multi-directional polarized reflectance measurements is applied to measurements of the airborne Research Scanning Polarimeter (RSP obtained during the CRYSTAL-FACE campaign in 2002. The method assumes individual hexagonal ice columns and plates serve as proxies for more complex shapes and aggregates. The closest fit is searched in a look-up table of simulated polarized reflectances computed for cloud layers that contain individual, randomly oriented hexagonal columns and plates with a virtually continuous selection of aspect ratios and distortion. The asymmetry parameter, aspect ratio and distortion of the hexagonal particle that leads to the best fit with the measurements are considered the retrieved values. Two cases of thick convective clouds and two cases of thinner anvil cloud layers are analyzed. Median asymmetry parameters retrieved by the RSP range from 0.76 to 0.78, and are generally smaller than those currently assumed in most climate models and satellite retrievals. In all cases the measurements indicate roughened or distorted ice crystals, which is consistent with previous findings. Retrieved aspect ratios in three of the cases range from 0.9 to 1.6, indicating compact particles dominate the cloud-top shortwave radiation. Retrievals for the remaining case indicate plate-like ice crystals with aspect ratios around 0.3. The RSP retrievals are qualitatively consistent with the CPI images obtained in the same cloud layers. Retrieved asymmetry parameters are compared to those determined in situ by the Cloud Integrating Nephelometer (CIN. For two cases, the median values of asymmetry parameter retrieved by CIN and RSP agree within 0.01, while for the two other cases RSP asymmetry parameters are about 0.03–0.05 greater than those obtained by the CIN. Part of this bias might be explained by vertical variation of the asymmetry parameter or ice shattering on the CIN probe, or both.

  3. Remote sensing of ice crystal asymmetry parameter using multi-directional polarization measurements - Part 2: Application to the Research Scanning Polarimeter

    Science.gov (United States)

    van Diedenhoven, B.; Cairns, B.; Fridlind, A. M.; Ackerman, A. S.; Garrett, T. J.

    2013-03-01

    A new method to retrieve ice cloud asymmetry parameters from multi-directional polarized reflectance measurements is applied to measurements of the airborne Research Scanning Polarimeter (RSP) obtained during the CRYSTAL-FACE campaign in 2002. The method assumes individual hexagonal ice columns and plates serve as proxies for more complex shapes and aggregates. The closest fit is searched in a look-up table of simulated polarized reflectances computed for cloud layers that contain individual, randomly oriented hexagonal columns and plates with a virtually continuous selection of aspect ratios and distortion. The asymmetry parameter, aspect ratio and distortion of the hexagonal particle that leads to the best fit with the measurements are considered the retrieved values. Two cases of thick convective clouds and two cases of thinner anvil cloud layers are analyzed. Median asymmetry parameters retrieved by the RSP range from 0.76 to 0.78, and are generally smaller than those currently assumed in most climate models and satellite retrievals. In all cases the measurements indicate roughened or distorted ice crystals, which is consistent with previous findings. Retrieved aspect ratios in three of the cases range from 0.9 to 1.6, indicating compact particles dominate the cloud-top shortwave radiation. Retrievals for the remaining case indicate plate-like ice crystals with aspect ratios around 0.3. The RSP retrievals are qualitatively consistent with the CPI images obtained in the same cloud layers. Retrieved asymmetry parameters are compared to those determined in situ by the Cloud Integrating Nephelometer (CIN). For two cases, the median values of asymmetry parameter retrieved by CIN and RSP agree within 0.01, while for the two other cases RSP asymmetry parameters are about 0.03-0.05 greater than those obtained by the CIN. Part of this bias might be explained by vertical variation of the asymmetry parameter or ice shattering on the CIN probe, or both.

  4. Coagulation parameters and platelet function analysis in patients with acromegaly.

    Science.gov (United States)

    Colak, A; Yılmaz, H; Temel, Y; Demirpence, M; Simsek, N; Karademirci, İ; Bozkurt, U; Yasar, E

    2016-01-01

    Acromegaly is associated with increased cardiovascular morbidity and mortality. The data about the evaluation of coagulation and fibrinolysis in acromegalic patients are very limited and to our knowledge, platelet function analysis has never been investigated. So, we aimed to investigate the levels of protein C, protein S, fibrinogen, antithrombin 3 and platelet function analysis in patients with acromegaly. Thirty-nine patients with active acromegaly and 35 healthy subjects were included in the study. Plasma glucose and lipid profile, fibrinogen levels, GH and IGF-1 levels and protein C, protein S and antithrombin III activities were measured in all study subjects. Also, platelet function analysis was evaluated with collagen/ADP and collagen-epinephrine-closure times. Demographic characteristics of the patient and the control were similar. As expected, fasting blood glucose levels and serum GH and IGF-1 levels were significantly higher in the patient group compared with the control group (pglc: 0.002, pGH: 0.006, pIGF-1: 0.001, respectively). But lipid parameters were similar between the two groups. While serum fibrinogen and antithrombin III levels were found to be significantly higher in acromegaly group (p fibrinogen: 0.005 and pantithrombin III: 0.001), protein S and protein C activity values were significantly lower in the patient group (p protein S: 0.001, p protein C: 0.001). Also significantly enhanced platelet function (measured by collagen/ADP- and collagen/epinephrine-closure times) was demonstrated in acromegaly (p col-ADP: 0.002, p col-epinephrine: 0.002). The results did not change, when we excluded six patients with type 2 diabetes in the acromegaly group. There was a negative correlation between serum GH levels and protein S (r: -0.25, p: 0.04)) and protein C (r: -0.26, p: 0.04) values. Likewise, there was a negative correlation between IGF-1 levels and protein C values (r: -0.39, p: 0.002), protein S values (r: -0.39, p: 0.001), collagen

  5. Crystallization and preliminary X-ray diffraction analysis of two N-terminal fragments of the DNA-cleavage domain of topoisomerase IV from Staphylococcus aureus.

    Science.gov (United States)

    Carr, Stephen B; Makris, George; Phillips, Simon E V; Thomas, Christopher D

    2006-11-01

    DNA topoisomerase IV removes undesirable topological features from DNA molecules in order to help maintain chromosome stability. Two constructs of 56 and 59 kDa spanning the DNA-cleavage domain of the A subunit of topoisomerase IV from Staphylococcus aureus (termed GrlA56 and GrlA59) have been crystallized. Crystals were grown at 291 K using the sitting-drop vapour-diffusion technique with PEG 3350 as a precipitant. Preliminary X-ray analysis revealed that GrlA56 crystals belong to space group P2(1), diffract to a resolution of 2.9 A and possess unit-cell parameters a = 83.6, b = 171.5, c = 87.8 A, beta = 90.1 degrees, while crystals of GrlA59 belong to space group P2(1)2(1)2, with unit-cell parameters a = 41.5, b = 171.89, c = 87.9 A. These crystals diffract to a resolution of 2.8 A. This is the first report of the crystallization and preliminary X-ray analysis of the DNA-cleavage domain of a topoisomerase IV from a Gram-positive organism.

  6. Translation effects on vertical Bridgman growth and optical, mechanical and surface analysis of 2-phenylphenol single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Sadhasivam, S., E-mail: sadha.phy1@gmail.com [Department of Physics, Center for Crystal Growth, SSN College of Engineering, Tamil Nadu, India-603 110 (India); Perumal, Rajesh Narayana

    2016-05-06

    2-phenylphenol optical crystals were grown in cone ampoules using vertical Bridgman technique. Single crystal of 2-phenylphenol with 150 mm length has been grown. The inclination on the conical part of the ampoule reduces the growth defects in the 2-phenylphenol single crystal. The lattice parameters and structure studied using single crystal X-ray diffraction method. 2-phenylphenol single crystal belongs to orthorhombic space group Fdd2. The micro translation rate affects crystal growth of 2-phenylphenol crystal was studied. The translation rate dependent defects present in the crystal were investigated by transmittance, indentation and etching characterizations. The dislocation induced indentation crack lengths variations were studied. Etch pits and striations observed for the selective etchants furnish significant information on growth aspects and degree of defect present in the crystal.

  7. Translation effects on vertical Bridgman growth and optical, mechanical and surface analysis of 2-phenylphenol single crystal

    Science.gov (United States)

    Sadhasivam, S.; Perumal, Rajesh Narayana

    2016-05-01

    2-phenylphenol optical crystals were grown in cone ampoules using vertical Bridgman technique. Single crystal of 2-phenylphenol with 150 mm length has been grown. The inclination on the conical part of the ampoule reduces the growth defects in the 2-phenylphenol single crystal. The lattice parameters and structure studied using single crystal X-ray diffraction method. 2-phenylphenol single crystal belongs to orthorhombic space group Fdd2. The micro translation rate affects crystal growth of 2-phenylphenol crystal was studied. The translation rate dependent defects present in the crystal were investigated by transmittance, indentation and etching characterizations. The dislocation induced indentation crack lengths variations were studied. Etch pits and striations observed for the selective etchants furnish significant information on growth aspects and degree of defect present in the crystal.

  8. Theoretical Analysis and Derivation of Combustion Wave Parameters

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun

    2006-01-01

    Theoretical relations of pressure, density, velocity, temperature and Mach number of combustion waves are built. The parameters' curves with different combustion energy are illustrated in which four zones are pointed out to represent different combustion states. The expressions and curves of parameters are important to analyze the trends of combustion waves, and to determine conditions on which detonation waves or deflagration waves occur.

  9. Effect of impurities and growth parameters on the quality of Tl3AsSe3 optical crystal

    Science.gov (United States)

    Singh, N. B.; Su, Ching-Hua; Arnold, Bradley; Choa, Fow-Sen; Nagaradona, Teja

    2016-10-01

    Thallium arsenic selenide (Tl3AsSe3) stoichiometric source materials suitable for crystal growth was synthesized in a horizontal furnace using purified parent components Tl, As and Se. Single crystal was grown using a two zone vertical Bridgman furnace using capillary for nucleation. A thermal gradient 18-20 K/cm and growth speed of 1 cm/day was used in vertical Bridgman furnace during crystal growth. Crystals were free from micro cracks and precipitates and demonstrated good fabricability. Results indicated that lower gradient and low growth rate are key to reduce thermal stresses in this ternary Tl-As-Se material system. Measured dielectric values in the range of 10 Hz to 100 KHz were almost constant indicating its suitability for applications in a range of frequency where constant dielectric is required.

  10. The effects of initial welding temperature and welding parameters on the crystallization behaviors of laser spot welded Zr-based bulk metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huei-Sen, E-mail: huei@mail.isu.edu.tw [Department of Materials Science and Engineering, I-Shou University, Kaohsiung County 84001, Taiwan (China); Chiou, Mau-Sheng; Chen, Hou-Guang [Department of Materials Science and Engineering, I-Shou University, Kaohsiung County 84001, Taiwan (China); Jang, Jason Shian-Ching [Department of Mechanical Engineering, National Central University, Taoyuan County 32001, Taiwan (China)

    2011-09-15

    This study investigated the effects of the initial welding temperature (IWT) and welding parameters on the crystallization behaviors of laser spot welded (Zr{sub 53}Cu{sub 30}Ni{sub 9}Al{sub 8})Si{sub 0.5} bulk metallic glass (BMG). After the welding process, the microstructure evolution, glass-forming ability (GFA) and mechanical properties of the welded samples were determined by a combination of scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and the Vicker's micro-hardness test. The results showed that the heat-affected zone (HAZ) crystallization seemed avoidable under the room temperature welding process. However, with a combination of a lower energy input (welding Condition C) and a lower IWT (at 0 deg. C), a crystallization-free HAZ was finally obtained. Using the above welding condition into the refined heat flow equation, a critical retention time of 79 ms for the crystallization temperature interval was estimated. Moreover, as the laser welded samples came to crystallization in the HAZ, it was observed that a higher content of spherical-type crystalline precipitates tended to result in a higher value of glass transition temperature, T{sub g}. Therefore, the GFA indices, {Delta}T{sub x}, {gamma} and {gamma}{sub m}, were reduced. Furthermore, it was found that the micro-hardness value in the HAZ crystallization area was decreased due to the massive cracks formed in most parts of the crystalline precipitates. For a crystallization-free HAZ, the hardness seemed unaffected.

  11. single crystal growth, x-ray structure analysis, optical band gap ...

    African Journals Online (AJOL)

    2015-09-01

    Sep 1, 2015 ... absorption spectra illustrate the change in opticalband gap from 3.01eVto ... Keywords: Single crystal growth; structure analysis; optical Eg; Raman spectra; strain tensor ... Journal of Fundamental and Applied Sciences.

  12. Effects of Parameter Modulation on Near-Field Imaging in Photonic Crystal Consisting of Alternately Left-Handed Material and Right-Handed Material

    Institute of Scientific and Technical Information of China (English)

    WANG Qiong; YAN Chang-Chun; ZHANG Ling-Ling; CUI Yi-Ping

    2008-01-01

    @@ By means of the transfer-matrix method, the effects of parameter modulation on the quality of near-field imaging in one-dimensional photonic crystal consisting of alternately Lett-handed material and right-handed material are investigated.Based on analyses of the recovery rate and ph'ase shift, the results show that the imaging quality is not obviously affected by the minor changes of layer thickness.In addition, by modulating the material parameters of the Lett-handed material, it is found that for both the real part and the imaginary part, the system is more sensitive to the permeability than the permittivity for the TE wave.For the TM wave, it is reverse.These properties are very useful to fabricate Lett-handed material photonic crystals in practice.

  13. Growth, spectral, optical, thermal, surface analysis and third order nonlinear optical properties of an organic single crystal: 1-(2-Methyl-6-nitro-4-phenyl-3-quinolyl) ethanone.

    Science.gov (United States)

    Nirosha, M; Kalainathan, S; Sarveswari, S; Vijayakumar, V; Srikanth, A

    2015-02-25

    Single crystal of 1-(2-Methyl-6-nitro-4-phenyl-3-quinolyl) ethanone was grown using slow evaporation solution growth technique. Single crystal X-ray diffraction study reveals the lattice parameters of the grown crystal. The modes of vibration of different molecular groups present in 2M6NQE were identified by FTIR spectral analysis. Its optical behavior was examined through UV-vis-NIR absorption and PL emission spectrum. They signify that the crystal has transparency in the region between 383 and 1100 nm. The PL spectrum of the title compound shows green emission in the crystal. From the thermal analysis, 2M6NQE has found to be thermally stable up to 263°C, and the melting point of the material is 170°C. The estimations of third order non-linear optical properties like non-linear absorption coefficient (β), non-linear refractive index (n2) and susceptibility [χ(3)] were calculated using Z-scan technique. It has observed that, crystal exhibits reverse saturation absorption and self-defocusing performance. Etching study was carried out for the grown crystal using different solvents. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Optimization of process parameters during vibratory welding technique using Taguchi's analysis

    Directory of Open Access Journals (Sweden)

    Pravin Kumar Singh

    2016-09-01

    Full Text Available With an aim to improve the mechanical properties of a weld joint, a new concept of vibratory setup has been designed which is capable to stir the molten weld pool before it solidifies during shielded metal arc welding (SMAW operation. Mechanical vibration having resonance frequency of 300 Hz and amplitude of 0.5 mm was transferred to the molten weld pool of 6 mm thick mild steel butt-welded joints during the welding operation. The experimental work was conducted at various ranges of frequencies, welding current and welding speed. Taguchi's analysis technique has been applied to optimize the process parameters; the response values for analysis are yield strength and micro-hardness. The test results showed that with the application of the vibratory treatment the values of hardness and tensile properties increased. The auxiliary vibrations induced into the weld pool resulted in increased micro-hardness of the weld metal which indicates the orientation of the crystal and refinement of grains took place. This study shows that vibration applied into the weld pool can be successfully improved the mechanical properties of welded joints. Thus this research attempt provided an alternative welding technique for grain refinement of weldments.

  15. Determination of the Dalitz plot parameter alpha for the decay eta->3pi^0 with the Crystal Ball at MAMI-B

    CERN Document Server

    Unverzagt, M; Ahrens, J; Annand, J R M; Arends, H J; Beck, R; Bekrenev, V; Boillat, B; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J W; Cherepnya, S; Codling, R; Downie, E J; Filkov, L V; Glazier, D I; Gregor, R; Heid, E; Hornidge, D; Jahn, O; Kashevarov, V L; Kondratiev, R; Korolija, M; Kotulla, M; Krambrich, D; Krusche, B; Lang, M; Lisin, V; Livingston, K; Lugert, S; MacGregor, I J D; Manley, D M; Martinez-Fabregate, M; McGeorge, J C; Mekterovic, D; Metag, V; Nefkens, B M K; Nikolaev, A; Novotny, R; Owens, R O; Pedroni, P; Polonski, A; Prakhov, S N; Price, J W; Rosner, G; Rost, M; Rostomyan, T; Schumann, S; Sober, D; Starostin, A; Supek, I; Tarbert, C M; Thomas, A; Walcher, Th; Watts, D P; Zehr, F

    2008-01-01

    A precise measurement of the Dalitz plot parameter, alpha, for the eta->3pi^0 decay is presented. The experiment was performed with the Crystal Ball and TAPS large acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8*10^6 eta->3pi^0 events were obtained, giving the result alpha = -0.032 \\pm 0.002_{stat} \\pm 0.002_{syst}.

  16. Crystallization and preliminary X-ray diffraction analysis of the magnesium transporter CorA.

    Science.gov (United States)

    Payandeh, Jian; Pai, Emil F

    2006-02-01

    The full-length integral membrane protein CorA from Thermotoga maritima (TmCorA(1-351)) has been expressed in Escherichia coli and purified without membrane isolation. TmCorA(1-351) crystallized in the monoclinic space group C2, with unit-cell parameters a = 214.25, b = 86.30, c = 181.53 A, beta = 112.23 degrees. Native crystals diffracted to 3.7 A using synchrotron radiation, but selenomethionine-substituted crystals rarely diffracted to better than 5.0 A. All full-length protein crystals were highly mosaic and produced anisotropic diffraction patterns. To aid in crystallographic phasing, soluble domain constructs were screened and the periplasmic domain of CorA from Archaeoglobus fulgidus (AfCorA(1-263)) was crystallized in the hexagonal space group P6(1)22, with unit-cell parameters a = b = 101.17, c = 142.87 A. Native and SeMet-substituted AfCorA(1-263) crystals diffracted to approximately 3.0 A using synchrotron radiation.

  17. Complex assembly, crystallization and preliminary X-ray crystallographic analysis of the human Rod–Zwilch–ZW10 (RZZ) complex

    Energy Technology Data Exchange (ETDEWEB)

    Altenfeld, Anika; Wohlgemuth, Sabine [Max Planck Institute of Molecular Physiology, Otto Hahn Strasse 11, 44227 Dortmund (Germany); Wehenkel, Annemarie [Institut Curie, CNRS UMR 3348/INSERM U1005, Bâtiment 110, Centre Universitaire, 91405 Orsay CEDEX (France); Vetter, Ingrid R. [Max Planck Institute of Molecular Physiology, Otto Hahn Strasse 11, 44227 Dortmund (Germany); Musacchio, Andrea, E-mail: andrea.musacchio@mpi-dortmund.mpg.de [Max Planck Institute of Molecular Physiology, Otto Hahn Strasse 11, 44227 Dortmund (Germany); University of Duisburg-Essen, Universitätstrasse 1, 45141 Essen (Germany)

    2015-03-20

    The 800 kDa complex of the human Rod, Zwilch and ZW10 proteins (the RZZ complex) was reconstituted in insect cells, purified, crystallized and subjected to preliminary X-ray diffraction analysis. The spindle-assembly checkpoint (SAC) monitors kinetochore–microtubule attachment during mitosis. In metazoans, the three-subunit Rod–Zwilch–ZW10 (RZZ) complex is a crucial SAC component that interacts with additional SAC-activating and SAC-silencing components, including the Mad1–Mad2 complex and cytoplasmic dynein. The RZZ complex contains two copies of each subunit and has a predicted molecular mass of ∼800 kDa. Given the low abundance of the RZZ complex in natural sources, its recombinant reconstitution was attempted by co-expression of its subunits in insect cells. The RZZ complex was purified to homogeneity and subjected to systematic crystallization attempts. Initial crystals containing the entire RZZ complex were obtained using the sitting-drop method and were subjected to optimization to improve the diffraction resolution limit. The crystals belonged to space group P3{sub 1} (No. 144) or P3{sub 2} (No. 145), with unit-cell parameters a = b = 215.45, c = 458.7 Å, α = β = 90.0, γ = 120.0°.

  18. Crystallization and Preliminary X-ray analysis of Human Recombinant Acid beta-glucocerebrosidase, a treatment for Gaucher's Disease

    Science.gov (United States)

    Roeber, Dana F.; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl - O - beta-D - glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme(R) (Genzyme Corporation, Cambridge, MA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is commercially available for the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. We report the crystallization and the initial diffraction analysis of Cerezyme(R). The crystals are C-centered orthorhombic, with unit-cell parameters of a = 285.0 A, b = 110.2 A, and c = 91.7 A. A 99.9 A complete data set has been collected to 2.75 A with an R(sub sym) of 8.8 %.

  19. Crystallization and preliminary X-ray analysis of recombinant human acid beta-glucocerebrosidase, a treatment for Gaucher's disease

    Science.gov (United States)

    Roeber, Dana; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.

    2003-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl-1-O-beta-D-glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme (Genzyme Corporation, Cambridge, MA, USA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is used in the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. Here, the crystallization and the initial diffraction analysis of Cerezyme are reported. The crystals are C-centered orthorhombic, with unit-cell parameters a = 285.0, b = 110.2, c = 91.7 A. A 99.9% complete data set has been collected to 2.75 A with an R(sym) of 8.8%.

  20. Effect of Operating Parameters and Chemical Additives on Crystal Habit and Specific Cake Resistance of Zinc Hydroxide Precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Alwin, Jennifer Louise [New Mexico State Univ., Las Cruces, NM (United States)

    1999-08-01

    The effect of process parameters and chemical additives on the specific cake resistance of zinc hydroxide precipitates was investigated. The ability of a slurry to be filtered is dependent upon the particle habit of the solid and the particle habit is influenced by certain process variables. The process variables studied include neutralization temperature, agitation type, and alkalinity source used for neutralization. Several commercially available chemical additives advertised to aid in solid/liquid separation were also examined in conjunction with hydroxide precipitation. A statistical analysis revealed that the neutralization temperature and the source of alkalinity were statistically significant in influencing the specific cake resistance of zinc hydroxide precipitates in this study. The type of agitation did not significantly effect the specific cake resistance of zinc hydroxide precipitates. The use of chemical additives in conjunction with hydroxide precipitation had a favorable effect on the filterability. The morphology of the hydroxide precipitates was analyzed using scanning electron microscopy.

  1. Wavelet Analysis on Solar Wind Parameters and Geomagnetic Indices

    CERN Document Server

    Katsavrias, Ch; Moussas, X

    2012-01-01

    The sun as an oscillator produces frequencies which propagate in the heliosphere, via solar wind, to the terrestrial magnetosphere. We searched for those frequencies in the parameters of the near Earth solar plasma and the geomagnetic indices for the past four solar cycles. The solar wind parameters used in this work are the interplanetary magnetic field, plasma beta, Alfven Mach number, solar wind speed, plasma temperature, plasma pressure, plasma density and the geomagnetic indices DST, AE, Ap and Kp. We found out that each parameter of the solar wind exhibit certain periodicities which di?erentiate in each cycle. Our results indicate intermittent periodicities in our data, some of them shared between the solar wind parameters and geomagnetic indices.

  2. Analysis of some meteorological parameters using artificial neural ...

    African Journals Online (AJOL)

    user

    2010-08-26

    Aug 26, 2010 ... artificial neural network method for Makurdi, Nigeria. Chukwu, S. C.1*, and ... the effects of meteorological parameters and finally prediction of solar ... intelligence techniques and are data-driven. Essentially,. ANN are used to ...

  3. Elastic orthorhombic anisotropic parameter inversion: An analysis of parameterization

    KAUST Repository

    Oh, Ju Won

    2016-09-15

    The resolution of a multiparameter full-waveform inversion (FWI) is highly influenced by the parameterization used in the inversion algorithm, as well as the data quality and the sensitivity of the data to the elastic parameters because the scattering patterns of the partial derivative wavefields (PDWs) vary with parameterization. For this reason, it is important to identify an optimal parameterization for elastic orthorhombic FWI by analyzing the radiation patterns of the PDWs for many reasonable model parameterizations. We have promoted a parameterization that allows for the separation of the anisotropic properties in the radiation patterns. The central parameter of this parameterization is the horizontal P-wave velocity, with an isotropic scattering potential, influencing the data at all scales and directions. This parameterization decouples the influence of the scattering potential given by the P-wave velocity perturbation fromthe polar changes described by two dimensionless parameter perturbations and from the azimuthal variation given by three additional dimensionless parameters perturbations. In addition, the scattering potentials of the P-wave velocity perturbation are also decoupled from the elastic influences given by one S-wave velocity and two additional dimensionless parameter perturbations. The vertical S-wave velocity is chosen with the best resolution obtained from S-wave reflections and converted waves, little influence on P-waves in conventional surface seismic acquisition. The influence of the density on observed data can be absorbed by one anisotropic parameter that has a similar radiation pattern. The additional seven dimensionless parameters describe the polar and azimuth variations in the P- and S-waves that we may acquire, with some of the parameters having distinct influences on the recorded data on the earth\\'s surface. These characteristics of the new parameterization offer the potential for a multistage inversion from high symmetry

  4. Thermal analysis of line-defect photonic crystal lasers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Ottaviano, Luisa; Chen, Yaohui

    2015-01-01

    We report a systematic study of thermal effects in photonic crystal membrane lasers based on line-defect cavities. Two material platforms, InGaAsP and InP, are investigated experimentally and numerically. Lasers with quantum dot layers embedded in an InP membrane exhibit lasing at room temperatur...

  5. CRYSTAL STRUCTURE ANALYSIS OF A PUTATIVE OXIDOREDUCTASE FROM KLEBSIELLA PNEUMONIAE

    Energy Technology Data Exchange (ETDEWEB)

    Baig, M.; Brown, A.; Eswaramoorthy, S.; Swaminathan, S.

    2009-01-01

    Klebsiella pneumoniae, a gram-negative enteric bacterium, is found in nosocomial infections which are acquired during hospital stays for about 10% of hospital patients in the United States. The crystal structure of a putative oxidoreductase from K. pneumoniae has been determined. The structural information of this K. pneumoniae protein was used to understand its function. Crystals of the putative oxidoreductase enzyme were obtained by the sitting drop vapor diffusion method using Polyethylene glycol (PEG) 3350, Bis-Tris buffer, pH 5.5 as precipitant. These crystals were used to collect X-ray data at beam line X12C of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). The crystal structure was determined using the SHELX program and refi ned with CNS 1.1. This protein, which is involved in the catalysis of an oxidation-reduction (redox) reaction, has an alpha/beta structure. It utilizes nicotinamide adenine dinucleotide phosphate (NADP) or nicotine adenine dinucleotide (NAD) to perform its function. This structure could be used to determine the active and co-factor binding sites of the protein, information that could help pharmaceutical companies in drug design and in determining the protein’s relationship to disease treatment such as that for pneumonia and other related pathologies.

  6. Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, Mamta [School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States); Moriyama, Hideaki, E-mail: hmoriyama2@unl.edu [Department of Chemistry, e-Toxicology and Biotechnology, University of Nebraska-Lincoln, Hamilton Hall, Lincoln, Nebraska 68588-0304 (United States); School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States)

    2007-05-01

    The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal. The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V{sub M} of 1.8 Å{sup 3} Da{sup −1}.

  7. Preparation, crystallization and preliminary crystallographic analysis of old yellow enzyme from Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Shigeru [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Tokuoka, Keiji [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Uchiyama, Nahoko [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Okamoto, Naoki; Okano, Yousuke; Matsumura, Hiroyoshi [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Inaka, Koji [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Urade, Yoshihiro [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Inoue, Tsuyoshi, E-mail: inouet@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan)

    2007-10-01

    Old yellow enzyme from Trypanosoma cruzi, has been crystallized using the hanging-drop vapour-diffusion method. Old yellow enzyme (OYE) is an NADPH oxidoreductase that contains a flavin mononucleotide as a prosthetic group. The OYE from Trypanosoma cruzi, which produces prostaglandin F{sub 2α}, a potent mediator of various physiological and pathological processes, from prostaglandin H2. The protein was recombinantly expressed and purified from Escherichia coli and was crystallized using the hanging-drop vapour-diffusion method. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 56.3, b = 78.8, c = 78.8 Å, β = 93.4° and two molecules per asymmetric unit. The crystals were suitable for X-ray crystallographic studies and diffracted to 1.70 Å resolution. A Patterson search method is in progress using the structure of OYE from Pseudomonas putida as a starting model.

  8. Crystallization and preliminary X-ray analysis of CTP:phosphoethanolamine cytidylyltransferase (ECT) from Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuka, Jun; Nagata, Koji; Lee, Woo Cheol [Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 (Japan); Ono, Yusuke; Fukuda, Ryouichi; Ohta, Akinori [Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 (Japan); Tanokura, Masaru, E-mail: amtanok@mail.ecc.u-tokyo.ac.jp [Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2006-10-01

    CTP:phosphoethanolamine cytidylyltransferase from S. cerevisiae has been expressed, purified and crystallized. CTP:phosphoethanolamine cytidylyltransferase (ECT) is the enzyme that catalyzes the conversion of phosphoethanolamine to CDP-ethanolamine in the phosphatidylethanolamine-biosynthetic pathway (Kennedy pathway). ECT from Saccharomyces cerevisiae was crystallized by the sitting-drop vapour-diffusion method using PEG 4000 as precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.88 Å resolution. The space group was assigned as primitive tetragonal, P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 66.3, c = 150.8 Å. The crystals contain one ECT molecule in the asymmetric unit (V{sub M} = 2.2 Å{sup 3} Da{sup −1}), with a solvent content of 43%.

  9. Energy-level structure and spectral analysis of Nd3+ in GdNbO4 crystal

    Science.gov (United States)

    Ding, Shoujun; Zhang, Qingli; Gao, Jinyun; Luo, Jianqiao; Liu, Wenpeng; Wang, XiaoFei; Sun, Guihua; Sun, Dunlu

    2017-02-01

    A detailed crystal-field splitting analysis is given for the 22 lowest-energy multiplet manifolds of Nd3+ (4f3) in GdNbO4 crystal. The absorption spectra obtained at room temperature, excitation spectra obtained at 8 K in the wavelength range of 280-900 nm, and emission spectra obtained between 8 K and room temperature in the wavelength range of 950-1420 nm are analyzed for transitions between individual energy (Stark) levels. Based on the excitation and absorption spectra, all of the 63 Stark levels associated with these manifolds are identified by transitions from the ground state Stark level 4I9/2 (Z1) to excited stark levels. Based on the emission spectra, the emitting stark level 4F3/2 (R1) to the stark levels in the manifolds of 4I9/2, 4I11/2 and 4I13/2 are obtained. The effective Judd-Ofelt parameters are calculated to be:6.126, 1.561, and 2.8071 × 10-20 cm2, respectively. All of the obtained energy level and spectroscopic parameters have great significance for the in-depth research of a new laser crystal of Nd:GdNbO4.

  10. Hydrostatic Parameters and Domain Effects in Novel 2-2 Composites Based on PZN-0.12PT Single Crystals

    Directory of Open Access Journals (Sweden)

    Vitaly Yu. Topolov

    2011-01-01

    Full Text Available A novel 0.88Pb(Zn1/3Nb2/3O3-0.12PbTiO3 crystal/polymer composite with 2-2 connectivity is studied at variable orientations of spontaneous polarisation vector of the crystal component. Orientation and volume-fraction dependences of the hydrostatic piezoelectric coefficients dh*, eh*, and gh* and hydrostatic electromechanical coupling factor kh* are related to the important role of the piezoelectric and elastic anisotropy of single-domain layers of the 2-2 composite. The record value of |eh∗|≈77 C/m2 near the absolute-minimum point and the correlation between the hydrostatic (eh* and piezoelectric (e3j* coefficients and between the hydrostatic (gh* and piezoelectric (g3j* coefficients are first established. This discovery is of value for hydrostatic and piezotechnical applications. The hydrostatic performance of the composite based on the single-domain 0.88Pb(Zn1/3Nb2/3O3-0.12PbTiO3 crystal is compared to the performance of the 2–2 composites based on either the same polydomain crystal or the related single-domain crystal.

  11. Improvement in the Plutonium Parameter Files of the FRAM Isotopic Analysis Code

    Energy Technology Data Exchange (ETDEWEB)

    D. T. Vo; T. E. Sampson

    2000-09-01

    The isotopic analysis code Fixed-energy Response-function Analysis with Multiple efficiency (FRAM) employs user-editable parameter sets to analyze a broad range of sample types. This report presents new parameter files, based upon a new set of plutonium branding ratios, which give more accurate isotope results than the current parameter files that use FRAM.

  12. Purification, crystallization and preliminary X-ray diffraction analysis of the kinase domain of human tousled-like kinase 2

    Energy Technology Data Exchange (ETDEWEB)

    Garrote, Ana M.; Redondo, Pilar [Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid (Spain); Montoya, Guillermo, E-mail: gmontoya@cnio.es [Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid (Spain); University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen (Denmark); Muñoz, Inés G., E-mail: gmontoya@cnio.es [Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid (Spain)

    2014-02-19

    The C-terminal kinase domain of TLK2 (a human tousled-like kinase) has been cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4{sub 1}22 and cubic P2{sub 1}3. Tousled-like kinases (TLKs) are an evolutionarily conserved family of serine/threonine protein kinases involved in chromatin dynamics, including DNA replication and repair, transcription and chromosome segregation. The two members of the family reported in humans, namely TLK1 and TLK2, localize to the cell nucleus and are capable of forming homo- or hetero-oligomers by themselves. To characterize the role of TLK2, its C-terminal kinase domain was cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4{sub 1}22 and cubic P2{sub 1}3. The latter produced the best diffracting crystal (3.4 Å resolution using synchrotron radiation), with unit-cell parameters a = b = c = 126.05 Å, α = β = γ = 90°. The asymmetric unit contained one protein molecule, with a Matthews coefficient of 4.59 Å{sup 3} Da{sup −1} and a solvent content of 73.23%.

  13. Crystal structure, Hirshfeld surface analysis, vibrational, thermal behavior and UV spectroscopy of (2,6-diaminopyridinium) dihydrogen arsenate

    Science.gov (United States)

    Bouaziz, Emna; Ben Hassen, Chawki; Chniba-Boudjada, Nassira; Daoud, Abdelaziz; Mhiri, Tahar; Boujelbene, Mohamed

    2017-10-01

    A new organic dihydrogenomonoarsenate (C5H8N3)H2AsO4 was synthesized by slow evaporation method at room temperature and characterized by X-ray single crystal diffraction. This compound crystallizes in the monoclinic system with the centro-symmetric space group P21/n. Unit cell parameters are a = 10.124 (5)Ǻ, b = 6.648 (5)Ǻ, c = 13.900 (5)Ǻ, β = 105.532° with Z = 4. The crystal structure was solved and refined to R = 0.038 with 2001 independent reflections. Hirshfeld surfaces analysis were used to visualize the fidelity of the crystal structure which has been determined by X-ray data collection on single crystals (C5H8N3)H2AsO4. Due the strong hydrogen Osbnd H⋯O bond network connecting the H2AsO4 groups, the anionic arrangement must be described as infinite (H2AsO4)nn-of dimers chains spreading, in a zig zag fashion, parallel to the b direction. The organic groups (C5H8N3)+ are anchored between adjacent polyanions through multiple hydrogen bonds Nsbnd H⋯O. The thermal decomposition of precursors studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), indicate the existence of two mass loss regions correspond to degradation of the title compound. The existence of vibrational modes correspond to the organic and inorganic groups are identified by the infrared and Raman spectroscopy in the frequency ranges 500-4000 and 25-4000 cm-1, respectively.

  14. Comparative analysis of lipid composition and thermal, polymorphic, and crystallization behaviors of granular crystals formed in beef tallow and palm oil.

    Science.gov (United States)

    Meng, Zong; Liu, Yuan-Fa; Jin, Qing-Zhe; Huang, Jian-Hua; Song, Zhi-Hua; Wang, Feng-Yan; Wang, Xing-Guo

    2011-02-23

    Six rectangular block all beef tallow (BT)-based and all palm oil (PO)-based model shortenings prepared on a laboratory scale, respectively denoted BTMS and POMS, were stored under temperature fluctuation cycles of 5-20 °C until granular crystals were observed. The lipid composition and thermal, polymorphic, and isothermal crystallization behaviors of the granular crystals and their surrounding materials separated from BTMS and POMS, respectively, were evaluated. The changes of nanostructure including the aggregation of high-melting triacylglycerols (TAGs) and polymorphic transformation from β' form of double chain length structures to complicated crystal structures, in which the β and β' form crystals of triple and double chain length structures simultaneously coexist, had occurred in granular crystals compared with surrounding materials, whether in BTMS or in POMS. Consequently, a slower crystallization rate appeared in granular crystal parts of both model shortenings noted above, which would yield larger and fewer crystals indicated by the Avrami model analysis that would further aggregate to form large granular crystals.

  15. Analysis of Discretionary Lane Changing Parameters on Freeways

    Directory of Open Access Journals (Sweden)

    Esmaeil Balal

    2014-09-01

    Full Text Available A lane changing event, at the instant when a vehicle crosses the lane marker, involves up to five vehicles: the subject vehicle, preceding and following vehicles in the original lane, and the preceding and following vehicles in the target lane. Understanding the interactions of the subject vehicle with the surrounding vehicles is fundamental to the study of the safety and modeling of lane changing behavior. This research studies the statistical properties of 10 lane changing parameters. These parameters describe the gaps, times to collision between vehicles and the subject vehicle's speed. The parameter values were extracted from the vehicle trajectory data in the Next Generation Simulation data sets. The results show that (i all the parameters are positively correlated with each other; (ii the gaps and distance are best described by the log-normal distribution; (ii the times to collision are best described by the Laplace distribution; (iii the speed may be described by the log-logistic distribution and the normal distribution. The results suggest that using one or few selected parameters may be sufficient to quantify the risk of a lane changing event.

  16. Crystal structure analysis of a hexatungstate by a high-energy X-ray diffraction experiment using an imaging plate Weissenberg camera at the BL04B2 beamline of SPring-8

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Tomoji; Honma, Noritaka [Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo (Japan); Kusaka, Katsuhiro [Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), Tokyo (Japan)

    2001-08-01

    An imaging plate Weissenberg camera was installed in the BL04B2 beamline of SPring-8 aiming at automated crystal structure determinations of small molecules. Since this beamline is designed to provide X-rays with the energies higher than 37 keV ({lambda}<0.33 A), this camera is advantageous in crystal structure analyses of heavily X-ray absorbing materials. The title crystal structure analysis led to precise positional parameters and well-behaved displacement parameters not only for heavy atoms but also for light atoms. (author)

  17. Structural considerations on acridine/acridinium derivatives: Synthesis, crystal structure, Hirshfeld surface analysis and computational studies

    Science.gov (United States)

    Wera, Michał; Storoniak, Piotr; Serdiuk, Illia E.; Zadykowicz, Beata

    2016-02-01

    This article describes a detailed study of the molecular packing and intermolecular interactions in crystals of four derivatives of acridine, i.e. 9-methyl-, 9-ethyl, 9-bromomethyl- and 9-piperidineacridine (1, 2, 3 and 4, respectively) and three 10-methylacridinium salts containing the trifluoromethanesulphonate anion and 9-vinyl-, 9-bromomethyl, and 9-phenyl-10-methylacridinium cations (5, 6 and 7, respectively). The crystal structures of all of the compounds are stabilized by long-range electrostatic interactions, as well as by a network of short-range C-HṡṡṡO (in hydrates and salts 3 and 5-7, respectively), C-Hṡṡṡπ, π-π, C-Fṡṡṡπ and S-Oṡṡṡπ (in salts 5-7) interactions. Hirshfeld surface analysis shows that various intermolecular contacts play an important role in the crystal packing, graphically exhibiting the differences in spatial arrangements of the acridine/acridinium derivatives under scrutiny here. Additionally, computational methods have been used to compare the intermolecular interactions in the crystal structures of the investigated compounds. Computations have confirmed the great contribution of dispersive interactions for crystal lattice stability in the case of 9-substituted acridine and electrostatic interactions for the crystal lattice stability in the case of 9-substituted 10-methylacridinium trifluoromethanesulphonates. The value of crystal lattice energy and the electrostatic contribution in the crystal lattice energy of monohydrated acridine derivatives have confirmed that these compounds have behave as acridinium derivatives.

  18. Analysis of distorted measurements -- parameter estimation and unfolding

    CERN Document Server

    Zech, Guenter

    2016-01-01

    1. Parameter inference from distorted measurements is discussed. 2. Smeared measurements are unfolded without explicit regularization. The corresponding results are unbiased and permit to fit parameters and to apply quantitative goodness-of-fit tests. 3. Common unfolding methods (iterative EM with early stopping, truncated SVD, ML fits with curvature, entropy and norm penalties) are tested and compared to each other with the regularization parameter adjusted to minimize the integrated square error (ISE) in all cases. Apart from histogram representations, spline approximations are considered. All simulations indicate that the EM method leads to smaller ISEs than the competing approaches. Especially promising is the EM unfolding to spline approximations. The studies are based on different distributions, event numbers, resolutions and enough independent simulations to obtain conclusive results. It is proposed to unfold data with the EM method to b-spline approximations and to supplement the results with histogra...

  19. CORRELATIVE ANALYSIS OF COSMIC RAY INTENSITY AND SOLAR ACTIVITY PARAMETERS

    Directory of Open Access Journals (Sweden)

    M. ROY

    2014-02-01

    Full Text Available Incoming cosmic ray shows significant intensity modulation in association with different solar geo parameters during their passage through heliosphere. Cosmic ray intensity is found anticorrelated with solar activity parameters. Using pressure corrected data of Mcmurdo neutron monitor, modulation of cosmic ray is analyzed covering solar cycles 21, 22, 23 and 24 (from 1976 to 2013. Negative and high correlations are obtained with some time lag for most of the solar parameters. Difference in shapes of hysteresis curves CRI~SSN, CRI~SRF. CRI~CI and CRI~FI for odd and even cycles pointed out that different mechanisms convection and diffusion are the dominating factors to drift cosmic ray particles.

  20. Spatial Analysis of Cities Using Renyi Entropy and Fractal Parameters

    CERN Document Server

    Chen, Yanguang

    2016-01-01

    Spatial distributions of cities fall into groups: one is the simple distribution with characteristic scale (e.g. exponential distribution), and the other is the complex distribution without characteristic scale (e.g. power-law distribution). The latter belongs to scale-free distributions, which can be modeled with fractal geometry. However, fractal dimension is suitable for the former distribution. In contrast, spatial entropy can be used to measure any types of urban distributions. This paper is devoted to developing multifractal parameters by means of the relation between entropy and fractal dimension. A new discovery is that normalized fractal dimension is equal to normalized entropy. Based on this finding, we can define a set of spatial indexes, which bears an analogy with the multifractal parameters. These indexes can be employed to describe both the simple distributions and complex distributions. The generalized fractal parameters are applied to the spatial density of population density of Hangzhou city...

  1. Parameter recognition for defocus blur image using cepstrum analysis

    Institute of Scientific and Technical Information of China (English)

    Zhou Qu; Yan Guozheng; Wang Wenxing

    2008-01-01

    Successful restoration of blurred images depends primarily on the knowledge about the degradation parameter.Defocus blur model in the frequency domain is characterized by concentric rings and the blur radius of the point spread function (PSF) can be identified conveniently in the frequency field for people by manual means rather than for computer.This paper introduces a practical method for computer to estimate the defocus blur parameter in cepstrum area.Fourier transform plays an intermediate role in the path to cepstrum domain.We suggest a weighted adjustment operation in the frequency domain and then convert it to the cepstrum field to increase the accuracy of recognition.

  2. Analysis and Optimization of Central Processing Unit Process Parameters

    Science.gov (United States)

    Kaja Bantha Navas, R.; Venkata Chaitana Vignan, Budi; Durganadh, Margani; Rama Krishna, Chunduri

    2017-05-01

    The rapid growth of computer has made processing more data capable, which increase the heat dissipation. Hence the system unit CPU must be cooled against operating temperature. This paper presents a novel approach for the optimization of operating parameters on Central Processing Unit with single response based on response graph method. These methods have a series of steps from of proposed approach which are capable of decreasing uncertainty caused by engineering judgment in the Taguchi method. Orthogonal Array value was taken from ANSYS report. The method shows a good convergence with the experimental and the optimum process parameters.

  3. Analysis of the carbon source for diamond crystal growth

    Institute of Scientific and Technical Information of China (English)

    LI Li; XU Bin; LI MuSen

    2008-01-01

    The lattice constants of diamond and graphite at high pressure and high temperature (HPHT) were calculated on the basis of linear expansion coefficient and elastic constant. According to the empirical electron theory of solids and molecules (EET), the valence electron structures (VESs) of diamond, graphite crystal and their common planes were calculated. The relationship between diamond and graphite structure was analyzed based on the boundary condition of the improved Thomas-Fermi-Dirac theory by Cheng (TFDC). It was found that the electron densities of common planes in graphite were not continuous with those of planes in diamond at the first order of approximation. The results show that during the course of diamond single crystal growth at HPHT with metal catalyst, the carbon sources forming diamond structure do not come from the graphite structure directly. The diamond growth mechanism was discussed from the viewpoint of valence electron structure.

  4. Analysis of switching conditions of chalcogenide alloys during crystallization

    Institute of Scientific and Technical Information of China (English)

    Wanhua Yu; C.D. Wright

    2006-01-01

    To understand the principle and limitation of chalcogenide alloy Ge2Sb2Te5 (GST) in solid-state memory devices during crystallization, it was necessary to develop a physically realistic model that could reflect the electrical and thermal properties of these media. A novel comprehensive numerical model has been developed for simulating these memory devices, which describes the electrical and thermal behavior using the solution of the nonlinear, time-dependent electrical and heat conduction equation. The finite-difference-time-domain technique was adopted to compute the electrical field and heat distribution in the device. Several contributing factors that affect the crystallization switching process such as the geometry of the GST layer, temperature and electric field dependency of the electrical conductivity have been discussed. The results of the simulations were then used to provide critical guidelines for fabrication and optimization of the device performance.

  5. Supermode analysis of the 18-core photonic crystal fiber laser

    Institute of Scientific and Technical Information of China (English)

    王远; 姚建铨; 郑一博; 温午麒; 陆颖; 王鹏

    2012-01-01

    The modal of 18-core photonic crystal fiber laser is discussed and calculated.And corresponding far-field distribution of the supermodes is given by Fresnel diffraction integral.For improving beam quality,the mode selection method based on the Talbot effect is introduced.The reflection coefficients are calculated,and the result shows that an in-phase supermode can be locked better at a large propagation distance.

  6. Analysis of the optical parameters of phase holographic gratings

    Directory of Open Access Journals (Sweden)

    Є.О. Тихонов

    2008-03-01

    Full Text Available  Suitability of 2- wave approximation of the coupled waves theory tor description of holographic phase gratings recorded on photopolymer compound ФПК-488 is proved. Using the basic formulas of the theory, main grating optical parameters - a depth of modulation and finished thickness are not measured immediately are determined.

  7. THE UNCERTAIN EIGENVALUES ANALYSIS OF STRUCTURES WITH UNCERTAIN PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    Guo Xuedong; Xie Jun; Chen Suhuan

    2000-01-01

    This paper presents a method for estimating the upper and lower bounds of eigenvalues of structures with uncertainties. The uncertain parameters are described by the convex model. A numerical ex ample of the frame structure is given to illustrate the efficiency of the method.

  8. Laser parameters of a Fe : ZnSe crystal in the 85-255-K temperature range

    NARCIS (Netherlands)

    Voronov, AA; Kozlovskii, [No Value; Korostelin, YV; Podmar'kov, YP; Frolov, MP

    The temperature dependence of the efficiency of a laser based on a Fe:ZnSe crystal grown from the vapour phase by the free-growth method is studied in the 85-255-K temperature range. As the temperature was increased, the slope efficiency of the laser with respect to absorbed energy decreased from

  9. 2-[(1E-({[(Benzylsulfanylmethanethioyl]amino}iminomethyl]-6-methoxyphenol: crystal structure and Hirshfeld surface analysis

    Directory of Open Access Journals (Sweden)

    Enis Nadia Md Yusof

    2016-04-01

    Full Text Available The title dithiocarbazate ester, C16H16N2O2S2, comprises two almost planar residues, i.e. the phenyl ring and the remaining 14 non-H atoms (r.m.s. deviation = 0.0410 Å. These are orientated perpendicularly, forming a dihedral angle of 82.72 (5°. An intramolecular hydroxy-O—H...N(imine hydrogen bond, leading to an S(6 loop, is noted. An analysis of the geometric parameters is consistent with the molecule existing as the thione tautomer, and the conformation about the C=N bond is E. The thione S and imine H atoms lie to the same side of the molecule, facilitating the formation of intermolecular N—H...S hydrogen bonds leading to eight-membered {...HNCS}2 synthons in the crystal. These aggregates are connected by phenyl-C—H...O(hydroxy interactions into a supramolecular layer in the bc plane; these stack with no directional interactions between them. An analysis of the Hirshfeld surface confirms the nature of the intermolecular interactions.

  10. Mapping residual stresses in PbWO$_{4}$ crystals using photo-elastic analysis

    CERN Document Server

    Lebeau, Michel; Majni, G; Paone, N; Pietroni, P; Rinaldi, D

    2005-01-01

    Large scintillating crystals are affected by internal stresses induced by the crystal growth temperature gradient remanence. Cutting boules (ingots) into finished crystal shapes allows for a partial tension relaxation but residual stresses remain the main cause of breaking. Quality control of residual stresses is essential in the application of Scintillating Crystals to high-energy physics calorimeters (e.g. CMS ECAL at CERN LHC). In this context the industrial process optimisation towards stress reduction is mandatory. We propose a fast technique for testing samples during the production process in order to evaluate the residual stress distribution after the first phases of mechanical processing. We mapped the stress distribution in PbWO/sub 4/slabs cut from the same production boule. The analysis technique is based on the stress intensity determination using the photo-elastic properties of the samples. The stress distribution is mapped in each sample. The analysis shows that there are regions of high residu...

  11. Purification, crystallization and preliminary X-ray crystallographic analysis of the CIDE-N domain of Fsp27.

    Science.gov (United States)

    Wang, Xiaodan; Zhang, Bo; Xu, Duo; Gao, Jinlan; Wang, Linfang; Wang, Zhi; Shan, Yaming; Yu, Xianghui

    2012-12-01

    Fsp27, a member of the CIDE protein family which is selectively expressed in adipocytes, has emerged as a novel regulator for unilocular lipid droplet (LD) formation, lipid metabolism, differentiation of adipocytes and insulin sensitivity. An LD is a subcellular compartment that is used by adipocytes for the efficient storage of fats. The CIDE-N domain of Fsp27 functions as a recruitment platform that induces the correct configuration of the Fsp27 CIDE-C domain to facilitate LD fusion. This study reports the high-yield expression of the mouse Fsp27 CIDE-N domain in Escherichia coli; a two-step purification protocol with high efficiency was established and crystallographic analysis was performed. The purity of the recombinant Fsp27 was >95% as assessed by SDS-PAGE. Crystals were obtained at 291 K using 28% polyethylene glycol 4000 as a precipitant. Diffraction data were collected to 1.92 Å resolution and the crystal belonged to space group P6(5), with unit-cell parameters a=b=63.3, c=37.4 Å, α=β=90, γ=120°. The components of the crystal were identified by ion-trap LC/MS/MS spectrometric analysis. The structure has been solved by molecular replacement and refinement is in progress.

  12. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Directory of Open Access Journals (Sweden)

    Cornelia Victoria Anghel

    2006-10-01

    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  13. Structure Analysis of Needle-like Copper Tantalum Trisulfide Crystals by XPS and Raman Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    CHENG Dan; JIN Hua; LI Ben-xian; WANG Xiao-feng; CHU Qing-xin; L(U) Yang; LIU Xiao-yang; ZHAO Xu-dong

    2012-01-01

    High-quality needle-like CuTaS3 single crystals have been synthesized through a chemical vapor transport(CVT)process.Crystallographic data show the special double chains of edge-sharing TaS6 octahedra.The detailed XPS analysis of CuTaS3 was undertaken and the valence states can be described by Cu+Ta5+3S2-.In addition,CuTaS3 crystals were characterized with Raman spectroscopy.

  14. Optical parametric oscillators in isotropic photonic crystals and cavities: 3D time domain analysis

    OpenAIRE

    Conti, Claudio; Di Falco, Andrea; Assanto, Gaetano

    2004-01-01

    We investigate optical parametric oscillations through four-wave mixing in resonant cavities and photonic crystals. The theoretical analysis underlines the relevant features of the phenomenon and the role of the density of states. Using fully vectorial 3D time-domain simulations, including both dispersion and nonlinear polarization, for the first time we address this process in a face centered cubic lattice and in a photonic crystal slab. The results lead the way to the development of novel p...

  15. Correlation analysis between pulmonary function test parameters and CT image parameters of emphysema

    Science.gov (United States)

    Liu, Cheng-Pei; Li, Chia-Chen; Yu, Chong-Jen; Chang, Yeun-Chung; Wang, Cheng-Yi; Yu, Wen-Kuang; Chen, Chung-Ming

    2016-03-01

    Conventionally, diagnosis and severity classification of Chronic Obstructive Pulmonary Disease (COPD) are usually based on the pulmonary function tests (PFTs). To reduce the need of PFT for the diagnosis of COPD, this paper proposes a correlation model between the lung CT images and the crucial index of the PFT, FEV1/FVC, a severity index of COPD distinguishing a normal subject from a COPD patient. A new lung CT image index, Mirage Index (MI), has been developed to describe the severity of COPD primarily with emphysema disease. Unlike conventional Pixel Index (PI) which takes into account all voxels with HU values less than -950, the proposed approach modeled these voxels by different sizes of bullae balls and defines MI as a weighted sum of the percentages of the bullae balls of different size classes and locations in a lung. For evaluation of the efficacy of the proposed model, 45 emphysema subjects of different severity were involved in this study. In comparison with the conventional index, PI, the correlation between MI and FEV1/FVC is -0.75+/-0.08, which substantially outperforms the correlation between PI and FEV1/FVC, i.e., -0.63+/-0.11. Moreover, we have shown that the emphysematous lesion areas constituted by small bullae balls are basically irrelevant to FEV1/FVC. The statistical analysis and special case study results show that MI can offer better assessment in different analyses.

  16. Spectral parameters of Nd3+ ion in Nd sup 3 sup + :LaCa sub 4 O(BO sub 3) sub 3 crystal

    CERN Document Server

    Yi, L

    2003-01-01

    The spectral parameters of Nd sup 3 sup + ions in Nd:LaCa sub 4 O(BO sub 3) sub 3 crystal have been investigated based on Judd-Ofelt theory. The spectral parameters were obtained: the intensity parameters OMEGA sublambda are OMEGA sub 2 =1.98 x 10 sup - sup 2 sup 0 cm sup 2 , OMEGA sub 4 =2.39 x 10 sup - sup 2 sup 0 cm sup 2 , OMEGA sub 6 =1.38 x 10 sup - sup 2 sup 0 cm sup 2 , the radioactive lifetime is 655 mu s, the quantum efficiency is 10%, and the fluorescence branch ratios were calculated: beta sub 1 = 0.51, beta sub 2 = 0.42, beta sub 3 = 0.066, beta sub 4 = 0.003. (orig.)

  17. Distortion Parameters Analysis Method Based on Improved Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    ZHANG Shutuan

    2013-10-01

    Full Text Available In order to realize the accurate distortion parameters test of aircraft power supply system, and satisfy the requirement of corresponding equipment in the aircraft, the novel power parameters test system based on improved filtering algorithm is introduced in this paper. The hardware of the test system has the characters of s portable and high-speed data acquisition and processing, and the software parts utilize the software Labwindows/CVI as exploitation software, and adopt the pre-processing technique and adding filtering algorithm. Compare with the traditional filtering algorithm, the test system adopted improved filtering algorithm can help to increase the test accuracy. The application shows that the test system with improved filtering algorithm can realize the accurate test results, and reach to the design requirements.  

  18. Crystallization and X-ray diffraction analysis of human CLEC-2

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Aleksandra A.; O’Callaghan, Christopher A., E-mail: chrisoc@ccmp.ox.ac.uk [Henry Wellcome Building of Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom)

    2005-12-01

    Recombinant human CLEC-2 was crystallized in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} and X-ray diffraction data were collected to 2.0 Å. The human C-type lectin-like protein CLEC-2 has recently been shown to be expressed on the surface of platelets and to function as a receptor for the snake-venom protein rhodocytin. The C-type lectin-like domain (CTLD) of CLEC-2 was expressed in Escherichia coli, refolded and purified. Crystals of this recombinant CLEC-2 were grown by sitting-drop vapour diffusion using polyethylene glycol (PEG) 6000 as a precipitant. After optimization, crystals were grown which diffracted to 2.0 Å using in-house radiation (λ = 1.5418 Å). These crystals belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 35.407, b = 55.143, c = 56.078 Å. The presence of one molecule per asymmetric unit is consistent with a crystal volume per unit weight (V{sub M}) of 1.82 Å{sup 3} Da{sup −1} and a solvent content of 32.6%. These results suggest that crystals producing diffraction of this quality will be suitable for the structural determination of human CLEC-2.

  19. Analysis QoS Parameters for MANETs Routing Protocols

    Directory of Open Access Journals (Sweden)

    S. R. Biradar

    2010-05-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a decentralized network of autonomous mobile nodes able to communicate with each other over wireless links. We selected three routing protocols DSDV, DSR and AODVfor measuring QoS parameters. We have used the network simulator ns-2 for simulating routing protocols using group mobility model, and present the results of simulations of networks of 40 wireless mobile nodes.

  20. Extracting Chaos Control Parameters from Time Series Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R B B [Centro Universitario da FEI, Avenida Humberto de Alencar Castelo Branco 3972, 09850-901, Sao Bernardo do Campo, SP (Brazil); Graves, J C, E-mail: rsantos@fei.edu.br [Instituto Tecnologico de Aeronautica, Praca Marechal Eduardo Gomes 50, 12228-900, Sao Jose dos Campos, SP (Brazil)

    2011-03-01

    We present a simple method to analyze time series, and estimate the parameters needed to control chaos in dynamical systems. Application of the method to a system described by the logistic map is also shown. Analyzing only two 100-point time series, we achieved results within 2% of the analytical ones. With these estimates, we show that OGY control method successfully stabilized a period-1 unstable periodic orbit embedded in the chaotic attractor.

  1. Stellar and wind parameters of massive stars from spectral analysis

    Science.gov (United States)

    Araya, I.; Curé, M.

    2017-07-01

    The only way to deduce information from stars is to decode the radiation it emits in an appropriate way. Spectroscopy can solve this and derive many properties of stars. In this work we seek to derive simultaneously the stellar and wind characteristics of A and B supergiant stars. Our stellar properties encompass the effective temperature, the surface gravity, the stellar radius, the micro-turbulence velocity, the rotational velocity and, finally, the chemical composition. For wind properties we consider the mass-loss rate, the terminal velocity and the line-force parameters (α, k and δ) obtained from the standard line-driven wind theory. To model the data we use the radiative transport code Fastwind considering the newest hydrodynamical solutions derived with Hydwind code, which needs stellar and line-force parameters to obtain a wind solution. A grid of spectral models of massive stars is created and together with the observed spectra their physical properties are determined through spectral line fittings. These fittings provide an estimation about the line-force parameters, whose theoretical calculations are extremely complex. Furthermore, we expect to confirm that the hydrodynamical solutions obtained with a value of δ slightly larger than ˜ 0.25, called δ-slow solutions, describe quite reliable the radiation line-driven winds of A and late B supergiant stars and at the same time explain disagreements between observational data and theoretical models for the Wind-Momentum Luminosity Relationship (WLR).

  2. Sensitivity analysis of permeability parameters for flows on Barcelona networks

    Science.gov (United States)

    Rarità, Luigi; D'Apice, Ciro; Piccoli, Benedetto; Helbing, Dirk

    We consider the problem of optimizing vehicular traffic flows on an urban network of Barcelona type, i.e. square network with streets of not equal length. In particular, we describe the effects of variation of permeability parameters, that indicate the amount of flow allowed to enter a junction from incoming roads. On each road, a model suggested by Helbing et al. (2007) [11] is considered: free and congested regimes are distinguished, characterized by an arrival flow and a departure flow, the latter depending on a permeability parameter. Moreover we provide a rigorous derivation of the model from fluid dynamic ones, using recent results of Bretti et al. (2006) [3]. For solving the dynamics at nodes of the network, a Riemann solver maximizing the through flux is used, see Coclite et al. (2005) [4] and Helbing et al. (2007) [11]. The network dynamics gives rise to complicate equations, where the evolution of fluxes at a single node may involve time-delayed terms from all other nodes. Thus we propose an alternative hybrid approach, introducing additional logic variables. Finally we compute the effects of variations on permeability parameters over the hybrid dynamics and test the obtained results via simulations.

  3. Viscoelasticity imaging using ultrasound: parameters and error analysis.

    Science.gov (United States)

    Sridhar, M; Liu, J; Insana, M F

    2007-05-07

    Techniques are being developed to image viscoelastic features of soft tissues from time-varying strain. A compress-hold-release stress stimulus commonly used in creep-recovery measurements is applied to samples to form images of elastic strain and strain retardance times. While the intended application is diagnostic breast imaging, results in gelatin hydrogels are presented to demonstrate the techniques. The spatiotemporal behaviour of gelatin is described by linear viscoelastic theory formulated for polymeric solids. Measured creep responses of polymers are frequently modelled as sums of exponentials whose time constants describe the delay or retardation of the full strain response. We found the spectrum of retardation times tau to be continuous and bimodal, where the amplitude at each tau represents the relative number of molecular bonds with a given strength and conformation. Such spectra indicate that the molecular weight of the polymer fibres between bonding points is large. Imaging parameters are found by summarizing these complex spectral distributions at each location in the medium with a second-order Voigt rheological model. This simplification reduces the dimensionality of the data for selecting imaging parameters while preserving essential information on how the creeping deformation describes fluid flow and collagen matrix restructuring in the medium. The focus of this paper is on imaging parameter estimation from ultrasonic echo data, and how jitter from hand-held force applicators used for clinical applications propagate through the imaging chain to generate image noise.

  4. Exploring charge density analysis in crystals at high pressure: data collection, data analysis and advanced modelling.

    Science.gov (United States)

    Casati, Nicola; Genoni, Alessandro; Meyer, Benjamin; Krawczuk, Anna; Macchi, Piero

    2017-08-01

    The possibility to determine electron-density distribution in crystals has been an enormous breakthrough, stimulated by a favourable combination of equipment for X-ray and neutron diffraction at low temperature, by the development of simplified, though accurate, electron-density models refined from the experimental data and by the progress in charge density analysis often in combination with theoretical work. Many years after the first successful charge density determination and analysis, scientists face new challenges, for example: (i) determination of the finer details of the electron-density distribution in the atomic cores, (ii) simultaneous refinement of electron charge and spin density or (iii) measuring crystals under perturbation. In this context, the possibility of obtaining experimental charge density at high pressure has recently been demonstrated [Casati et al. (2016). Nat. Commun. 7, 10901]. This paper reports on the necessities and pitfalls of this new challenge, focusing on the species syn-1,6:8,13-biscarbonyl[14]annulene. The experimental requirements, the expected data quality and data corrections are discussed in detail, including warnings about possible shortcomings. At the same time, new modelling techniques are proposed, which could enable specific information to be extracted, from the limited and less accurate observations, like the degree of localization of double bonds, which is fundamental to the scientific case under examination.

  5. X-Ray Diffraction Analysis of NLO Crystals: Traditional Applications and More New Opportunities

    Science.gov (United States)

    Antipin, Mikhail Yu.; Clark, Ronald D.; Nesterov, Vladimir N.

    1998-01-01

    Single crystal X-ray diffraction analysis is one of the more important methods for the molecular and crystal structure determination of matter and therefore it has a great importance in material science including design and engineering of different compounds with non-linear optical (NLO) properties. It was shown in our previous publications that this method provides unique information about molecular structure of NLO compounds, their crystal symmetry and crystal packing arrays, molecular conformation and geometries and many other structural and electronic characteristics that are important for understanding the nature of NLO properties of solids. A very new application of the X-ray diffraction method is related to analysis of the electron density distribution p(r) in crystals and some of its characteristics (atomic and group charges, dipole and higher multipole moments, etc.), that may be obtained directly form the diffraction measurements. In the present work, we will discuss our preliminary low temperature high-resolution X-ray data for the m-nitroaniline (mNA) single crystal (VI). This is one of the "classical" organic NLO materials and electron density distribution analysis in this simple compound has a great scientific interest.

  6. Effects of Additive AlCl3 on Crystal Phase, Particle Size and Microstructural Parameters of Nanocrystalline TiO2 Prepared by HF-PCVD

    Institute of Scientific and Technical Information of China (English)

    Haiping XU; Yanping SUN; Xinmou CHEN

    2004-01-01

    Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructural parameters of TiO2 nanocrystallites were investigated by X-ray diffraction(XRD) and transmission electron microscopy (TEM). The nanocrystallites obtained experimentally are mixture of anatase and rutile, the uniform diameters of particles are about 30 nm. The phase transformation from anatase to rutile was accelerated by AlCl3, and rutile content is increased from 26.7 wt pct to 53.6 wt pct with increasing of addition of AlCl3 from 0.0 wt pct to 5.0 wt pct. The particle size is reduced and the size distribution becomes very narrow. The crystal lattice constants have the trend to decrease, and cell volumes appear as shrinkable.

  7. Simple method for the determination of refractive indices and loss parameters for liquid-crystal materials in the millimeter-wave region.

    Science.gov (United States)

    Nose, Toshiaki; Honma, Michinori; Nozokido, Tatsuo; Mizuno, Koji

    2005-03-01

    A reflection-type liquid crystal (LC) test cell is prepared with a rectangular waveguide for investigation of a novel method to determine refractive indices and loss parameters of nematic liquid-crystal materials. As the bottom of the test cell is sealed with a glass window and the top of the cell is capped with a metal-tipped movable reflector after the LC materials are injected, both ends of the waveguide test cell have large reflectance. Thus the reflection properties of the LC test cell can be well described by a multiple-beam interference model. A simple method for the determination of refractive indices from the reflection measurement data is proposed based on results of some investigations with the theoretical model. Commercially available LC materials have been measured with this method at a millimeter-wave frequency (50 GHz) by use of a simple experimental setup with a Gunn oscillator and a diode detector.

  8. Analysis of the temperature dependence of the thermal conductivity of insulating single crystal oxides

    Directory of Open Access Journals (Sweden)

    E. Langenberg

    2016-10-01

    Full Text Available The temperature dependence of the thermal conductivity of 27 different single crystal oxides is reported from ≈20 K to 350 K. These crystals have been selected among the most common substrates for growing epitaxial thin-film oxides, spanning over a range of lattice parameters from ≈3.7 Å to ≈12.5 Å. Different contributions to the phonon relaxation time are discussed on the basis of the Debye model. This work provides a database for the selection of appropriate substrates for thin-film growth according to their desired thermal properties, for applications in which heat management is important.

  9. Design and analysis of dual ring resonator based 2D-photonic crystal WDDM

    Science.gov (United States)

    Venkatachalam, K.; Robinson, S.; Kumar, D. Sriram

    2017-06-01

    In this paper, four channel 2D Photonic Crystal (PC) based Wavelength Division Demultiplexer (WDDM) using 2D-Photonic Crystal is proposed and designed. The important functional parameters of the proposed demultiplexer such as transmission efficiency, Q factor and resonant wavelength are analyzed. The Plane Wave Expansion (PWE) method and Finite Difference Time Domain (FDTD) method are employed to calculate the photonic band gap and normalized output spectrum of the proposed demultiplexer. The average transmission efficiency and Q factor of this proposed device is about 93% and 781, respectively. The overall size of the demultiplexer is around 681 µm2 which will be suitable for integrated optics for future all optical networks.

  10. Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-[beta]-lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, N.; Toney, J.H.; Fitzgerald, P.M.D. (Merck)

    2010-07-20

    The CphA metallo-{beta}-lactamase from Aeromonas hydrophilia has been expressed, purified and crystallized by the hanging-drop vapor-diffusion method using ammonium sulfate as the precipitant. The crystals exhibit orthorhombic symmetry (P2{sub 1}2{sub 1}2), with unit-cell parameters a = 40.75, b = 42.05, c = 128.88 {angstrom}. There is one monomer in the asymmetric unit and the solvent content is estimated to be 44% by volume. A data set extending to 1.8 {angstrom} has been measured.

  11. Crystallization and initial X-ray diffraction analysis of a mannose-binding lectin from champedak.

    Science.gov (United States)

    Gabrielsen, Mads; Abdul-Rahman, Puteri Shafinaz; Isaacs, Neil W; Hashim, Onn Haji; Cogdell, Richard J

    2010-05-01

    Mannose-binding lectin from champedak (Artocarpus integer) is a homotetramer with a single-monomer molecular weight of 16 800 Da. Previous work has shown it to bind IgE and IgM, as well as being a mitogen of T cells in humans. Champedak mannose-binding lectin has successfully been used to detect altered glycosylation states of serum proteins. The protein was crystallized at 293 K in space group P2(1)2(1)2(1) (unit-cell parameters a = 76.89, b = 86.22, c = 95.37 A) and the crystals diffracted to 2.0 A resolution.

  12. Crystallization and preliminary X-ray diffraction analysis of myotoxin I, a Lys49-phospholipase A{sub 2} from Bothrops moojeni

    Energy Technology Data Exchange (ETDEWEB)

    Marchi-Salvador, D. P. [Departamento de Física e Biofísica-IB, UNESP, CP 510, CEP 18618-000, Botucatu-SP (Brazil); Silveira, L. B.; Soares, A. M. [Departamento de Biotecnologia, UNAERP, Ribeirão Preto/SP (Brazil); Fontes, M. R. M., E-mail: fontes@ibb.unesp.br [Departamento de Física e Biofísica-IB, UNESP, CP 510, CEP 18618-000, Botucatu-SP (Brazil)

    2005-10-01

    A new myotoxic Lys49-phospholipase from B. moojeni has been crystallized and X-ray diffraction data were collected to 2.18 Å resolution. Preliminary analysis indicates the presence of four molecules in the asymmetric unit, leading to a possible new oligomeric structure for Lys49-PLA{sub 2}s. A new myotoxic Lys49-phospholipase A{sub 2} isolated from Bothrops moojeni snake venom has been crystallized. The crystals diffracted to 2.18 Å resolution using a synchrotron-radiation source and belong to space group C2. The unit-cell parameters are a = 56.8, b = 125.0, c = 64.7 Å, β = 105.5°. Preliminary analysis indicates the presence of four molecules in the asymmetric unit. This may suggest a new quaternary structure for this Lys49-phospholipase A{sub 2} in contrast to the dimeric and monomeric structures solved so far for this class of proteins.

  13. Numerical analysis and simulation of Czochralski growth processes for large diameter silicon crystals

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Numerical analysis and simulation have been an effective means to develop the advanced growth technology and to control the defects type, size and density for silicon crystals of 300 mm and beyond In the present paper, numerical analysis of the melt flow in the Czochralski (CZ) crystal growth configuration, the three dimensional (3D) modeling, the simulation of melt flow under the magnetic field, the inverse modeling and the time-dependent simulation are reviewed. Finally, comparison of numerical analysis with experimental measurements is discussed.

  14. Tracking and Motion Analysis of Crack Propagations in Crystals for Molecular Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Tsap, L V; Duchaineau, M; Goldgof, D B

    2001-05-14

    This paper presents a quantitative analysis for a discovery in molecular dynamics. Recent simulations have shown that velocities of crack propagations in crystals under certain conditions can become supersonic, which is contrary to classical physics. In this research, they present a framework for tracking and motion analysis of crack propagations in crystals. It includes line segment extraction based on Canny edge maps, feature selection based on physical properties, and subsequent tracking of primary and secondary wavefronts. This tracking is completely automated; it runs in real time on three 834-image sequences using forty 250 MHZ processors. Results supporting physical observations are presented in terms of both feature tracking and velocity analysis.

  15. Crystallization Analysis and Control of Ammonia-Based Air Source Absorption Heat Pump in Cold Regions

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-01-01

    Full Text Available Energy consumption of heating and domestic hot water is very high and will keep increasing. Air source absorption heat pump (ASAHP was proposed to overcome the problems of low energy efficiency and high air pollution existing in boiler systems, as well as the problem of bad performance under low ambient temperatures for electrical heat pumps. In order to investigate the crystallization possibility of ammonia-salt ASAHP, crystallization margin (evaluated by solution mass concentration at generating temperature ranging from 100 to 150°C, evaporating temperature from −30 to 10°C, and condensing temperature from 30 to 65°C are analyzed. To prevent the NH3–NaSCN solution from crystallizing, ASAHP integrated with pressure booster located between the evaporator and absorber is simulated. Analysis and comparisons show that NH3–NaSCN is easy to crystallize at relatively high generating temperature, low evaporating temperature, and low condensing temperature. But crystallization margin of NH3–LiNO3 can always stay above 5% for most conditions, keeping away from crystallization. Pressure booster can effectively avoid the crystallization problem that will take place in the NH3–NaSCN ASAHP system.

  16. Low-temperature change of lattice parameters in LiKB{sub 4}O{sub 7} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Adamiv, Volodymyr; Burak, Yaroslav; Teslyuk, Ihor [Institute of Physical Optics, Lviv (Ukraine)

    2009-02-15

    Structural investigations of LiKB{sub 4}O{sub 7} crystals in the 13-290 K temperature range have been carried out by means of the high-resolution powder diffraction technique applying synchrotron radiation. It is shown that the structural phase transitions are absent and all the linear thermal expansion coefficients {alpha}{sub ij} are positive in the investigated temperature range. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Purification, crystallization and preliminary crystallographic analysis of the Hermes transposase

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Zhanita N.; Musingarimi, Primrose [Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD (United States); Craig, Nancy L. [Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins School of Medicine, Baltimore, MD (United States); Dyda, Fred; Hickman, Alison Burgess, E-mail: ahickman@helix.nih.gov [Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD (United States)

    2005-06-01

    Upon purification, an N-terminally deleted version of the Hermes transposase exists in solution as a mixture of two species that are approximately hexameric and dimeric. Crystals have been obtained of the smaller species that diffract to 2.1 Å resolution. DNA transposition is the movement of a defined segment of DNA from one location to another. Although the enzymes that catalyze transposition in bacterial systems have been well characterized, much less is known about the families of transposase enzymes that function in higher organisms. Active transposons have been identified in many insect species, providing tools for gene identification and offering the possibility of altering the genotypes of natural insect populations. One of these active transposons is Hermes, a 2749-base-pair element from Musca domestica that encodes its own transposase. An N-terminally deleted version of the Hermes transposase (residues 79–612) has been overexpressed and purified, and crystals that diffract to 2.1 Å resolution have been obtained at 277 K by the hanging-drop method.

  18. Analysis of thin-film photonic crystal microstructures

    CERN Document Server

    Pottage, J M

    2003-01-01

    Optical-scale microstructures containing thin-film photonic crystals (TFPCs) are modelled by transfer/scattering matrix methods, based on Fourier-series expansion of the optical Bloch eigenmodes. The majority of the TFPCs considered consist of 2D arrays of holes arranged in a triangular lattice, etched into high-index Al sub x Ga sub 1 sub - sub x As and placed on a low-index oxidised substrate. These TFPCs can be easily fabricated by standard electron-beam lithography techniques. Unlike most photonic crystal devices that have been proposed, our 'intra-pass-band' TFPCs would work by exploiting the somewhat surprising properties of propagating optical Bloch waves rather than directly relying on photonic bandgaps. By numerical modelling, it is demonstrated that 2D-patterned TFPCs can support highly dispersive high-Q quasi-guided and truly-guided resonant modes, and the unusual properties of these modes are explained in terms of their Bloch-wave compositions. Modal dispersion diagrams of TFPCs, showing the loci ...

  19. Crystal structure and conformational analysis of angiotensinogen fragments.

    Science.gov (United States)

    Benkoulouche, M; Cotrait, M; Geoffre, S; Precigoux, G

    1989-12-01

    The tripeptide acetyl-L-prolyl-L-phenylalanyl-L-histidine crystallizes in the orthorhombic space group P2(1)2(1)2(1) with eight molecules in a unit cell of dimensions a = 9.028(2), b = 140.54(6) and c = 42.41(1)A. The structure has been solved by direct methods and refined to an R value of 0.056 for 2904 observed reflections. The molecule exists as a zwitterion with terminal (His)CO2- and (imidazole)H+ as charged groups. The two peptide molecules in the structure adopt a type I beta-turn with Pro and Phe as the corner residues. The main conformational difference between the two crystallographically independent molecules is seen to be in the histidine side-chain orientations. The molecules arrange themselves in sheets perpendicular to the c axis. All hydrophobic side chains lie on one side of the sheets thus generated, whereas the hydrophilic groups are located on the other side. An interesting feature of the crystal structure is the existence of a water layer between adjacent peptide sheets. The conformational study of the isolated Ac-His-Pro-Phe-His-MA using energy calculations gives a rather limited number of stable conformers. The most stable corresponds to a type I beta-turn stabilized through two hydrogen bonds, followed by a less stable type II beta-turn (delta E = 2.0 kcal) and a partly helical structure (delta E = 2.6 kcal).

  20. Qualitative Analysis of Relationship between Refractive Index and Atomic Parameters of Solid Materials

    Institute of Scientific and Technical Information of China (English)

    罗遵度; 黄艺东

    2004-01-01

    The refractive index is one of the important parameters describing the optical properties of solid materials. However, it is difficult to obtain a quantitative relation between the refractive index and the structure and composition of materials. A qualitative relation between the refractive index and some atomic parameters of materials was proposed and demonstrated by some oxide optical crystals. A parameter P=r-/F=r-/(r+ΔxD) is defined, in which Δx is the difference of the electronegativities between cations and anions in the materials and r+ and r- are the radii of cations and anions respectively. On the other hand, the factor D was introduced to describe the effect of mass difference of the ions. It is demonstrated by both theoretical discussion and experimental data that refractive index is a decreasing function of parameter P. The relation may be useful for the investigation of optical materials.

  1. determination of weibull parameters and analysis of wind power ...

    African Journals Online (AJOL)

    HOD

    Resulting from the analysis, the values of the average wind speed, the average daily wind power, the ... Keywords: Wind power potential, Energy production, Weibull distribution, Wind ... was added globally in 2015 indicating a 23.2% increase.

  2. Statistical Analysis of I Stokes Parameter of Millisecond Pulsars

    CERN Document Server

    Panahi, Hossein; Monadi, Reza

    2016-01-01

    Using Detrended Fluctuation Analysis (DFA) and box counting method, we test spacial correlation and fractality of Polarization Pulse Profiles (PPPs) of 24 millisecond pulsars (MSPs) which were observed in Parkes Pulsar Timing Array (PPTA) project. DFA analysis indicates that MSPs' PPPs are persistent and the results of box counting method confirm the fractality in the majority of PPPs. A Kolmogorov-Smirnov test indicates that isolated MSPs have more complex PPPs than binary ones. Then we apply our analysis on a random sample of normal pulsars. Comparing the results of our analysis on MSPs and normal pulsars shows that MSPs have more complex PPPs which is resulted from smaller angular half-width of the emission cone and more peaks in MSPs PPPs. On the other hand, high values of Hurst exponent in MSPs confirm compact emission regions in these pulsars.

  3. ANALYSIS THE DIURNAL VARIATIONS ON SELECTED PHYSICAL AND PHYSIOLOGICAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    A. MAHABOOBJAN

    2010-12-01

    Full Text Available The purpose of the study was to analyze the diurnal variations on selected physical and physiological parameters such as speed, explosive power, resting heart rate and breath holding time among college students. To achieve the purpose of this study, a total of twenty players (n=20 from Government Arts College, Salem were selected as subjects To study the diurnal variation of the players on selected physiological and performance variables, the data were collected 4 times a day with every four hours in between the times it from 6.00 to 18.00 hours were selected as another categorical variable. One way repeated measures (ANOVA was used to analyze the data. If the obtained F-ratio was significant, Seheffe’s post-hoc test was used to find out the significant difference if anyamong the paired means. The level of significance was fixed at.05 level. It has concluded that both physical and physiological parameters were significantly deferred with reference to change of temperature in a day

  4. Crystallization analysis of AlMg (AG 10 alloy with use of ATND method

    Directory of Open Access Journals (Sweden)

    Ciućka T.

    2007-01-01

    Full Text Available The paper presents results of non-ferrous metal crystallization research with use of ATND method. The research was carried out in the Faculty of Chipless Forming Technology, University of Bielsko-Biała. The new method of analysis of non-ferrous metals alloy crystallization assures complete picture of generated structural components of the alloy. Structural components defined in the tested alloy using ATND method have been verified by X-ray microanalysis, which unambiguously has confirmed their presence. Below are presented results of the crystallization analysis with ATND method in graphic form (crystallization diagrams. In crystallization diagrams of AG10 alloy there were shown curves (thermal curve with its derivative, voltage curve and its derivative. Individual structural components crystallizing in the tested alloy are reflected on curves of the method in form of characteristic peaks. The research was carried out on AG10 aluminum-magnesium cast alloy. Moreover, the paper shows the structures of the tested alloy together with marked structural components, identified with use of X-ray microanalysis.

  5. Instrumental neutron activation analysis of an enriched 28Si single-crystal

    CERN Document Server

    DAgostino, G; Giordani, L; Mana, G; Oddone, M

    2013-01-01

    The determination of the Avogadro constant plays a key role in the redefinition of the kilogram in terms of a fundamental constant. The present experiment makes use of a silicon single-crystal highly enriched in 28Si that must have a total impurity mass fraction smaller than a few parts in 109. To verify this requirement, we previously developed a relative analytical method based on neutron activation for the elemental characterization of a sample of the precursor natural silicon crystal WASO 04. The method is now extended to fifty-nine elements and applied to a monoisotopic 28Si single-crystal that was grown to test the achievable enrichment. Since this crystal was likely contaminated, this measurement tested also the detection capabilities of the analysis. The results quantified contaminations by Ge, Ga, As, Tm, Lu, Ta, W and Ir and, for a number of the detectable elements, demonstrated that we can already reach the targeted 1 ng/g detection limit.

  6. Crystallization kinetics of poly-(lactic acid) with and without talc: Optical microscopy and calorimetric analysis

    Science.gov (United States)

    Refaa, Z.; Boutaous, M.; Rousset, F.; Fulchiron, R.; Zinet, M.; Xin, S.; Bourgin, P.

    2014-05-01

    Poly-(lactic acid) or PLA is a biodegradable polymer synthesized from renewable resources. Recently, the discovery of new polymerization routes has allowed increasing the produced volumes. As a consequence, PLA is becoming of great interest for reducing the dependence on petroleum-based plastics. Because of its interesting mechanical properties, PLA is seen as a potential substitute for some usual polymers. However, its relatively slow crystallization kinetics can be a disadvantage with regard to industrial applications. The crystallization kinetics of PLA can be enhanced by adding nucleating agents, which also influences on crystalline morphology and rheological behavior. In the present work, the isothermal quiescent crystallization kinetics of both neat PLA and PLA/talc composite (5 wt% talc) are investigated. The effects of talc on the overall crystallization kinetics and on the crystalline morphology are analyzed using both optical microscopy measurements and thermal analysis by differential scanning calorimetry.

  7. Electric field dependence of nonlinearity parameters and third order elastic constants of 0.70Pb(Mg(13)Nb(23))O(3)-0.30PbTiO(3) single crystal.

    Science.gov (United States)

    Liu, Xiaozhou; Zhang, Shujun; Luo, Jun; Shrout, Thomas R; Cao, Wenwu

    2010-02-01

    Through second harmonic measurements, the ultrasonic nonlinearity parameters of [001](c) and [111](c) polarized 0.70Pb(Mg(13)Nb(23))O(3)-0.30PbTiO(3)(PMN-0.3PT) single crystals have been measured as a function of bias electric field. It was found that the nonlinearity parameter increases almost linearly with field at low field but shows a drastic increase near the coercive field. The [111](c) polarized single domain crystal has much smaller nonlinearity parameter than that of the [001](c) polarized multidomain crystal. Based on effective symmetries of these crystals, we were able to derive the field dependence of several third order elastic constants, which are important parameters for high field applications.

  8. Electric field dependence of nonlinearity parameters and third order elastic constants of 0.70Pb(Mg1∕3Nb2∕3)O3–0.30PbTiO3 single crystal

    Science.gov (United States)

    Liu, Xiaozhou; Zhang, Shujun; Luo, Jun; Shrout, Thomas R.; Cao, Wenwu

    2010-01-01

    Through second harmonic measurements, the ultrasonic nonlinearity parameters of [001]c and [111]c polarized 0.70Pb(Mg1∕3Nb2∕3)O3–0.30PbTiO3(PMN–0.3PT) single crystals have been measured as a function of bias electric field. It was found that the nonlinearity parameter increases almost linearly with field at low field but shows a drastic increase near the coercive field. The [111]c polarized single domain crystal has much smaller nonlinearity parameter than that of the [001]c polarized multidomain crystal. Based on effective symmetries of these crystals, we were able to derive the field dependence of several third order elastic constants, which are important parameters for high field applications. PMID:20198132

  9. Determination of the Dalitz plot parameter {alpha} for the decay {eta}{yields}3{pi}{sup 0} with the Crystal Ball at MAMI-B

    Energy Technology Data Exchange (ETDEWEB)

    Unverzagt, M.; Beck, R.; Lang, M.; Nikolaev, A.; Schumann, S. [University Mainz, Institut fuer Kernphysik, Mainz (Germany); University Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Aguar-Bartolome, P.; Ahrens, J.; Arends, H.J.; Heid, E.; Jahn, O.; Krambrich, D.; Martinez-Fabregate, M.; Rost, M.; Thomas, A.; Walcher, T. [University Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Codling, R.; Livingston, K.; MacGregor, I.J.D.; McGeorge, J.C.; Owens, R.O.; Rosner, G. [University of Glasgow, Department of Physics and Astronomy, Glasgow (United Kingdom); Bekrenev, V. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Boillat, B.; Krusche, B.; Zehr, F. [University Basel, Institut fuer Physik, Basel (Switzerland); Braghieri, A.; Pedroni, P.; Rostomyan, T. [INFN Sezione di Pavia, Pavia (Italy); Branford, D.; Glazier, D.I.; Tarbert, C.M.; Watts, D.P. [Univ. of Edinburgh, School of Physics, Edinburgh (United Kingdom); Briscoe, W.J. [The George Washington Univ., Center for Nuclear Studies, Washington, D.C. (United States); Brudvik, J.W.; Nefkens, B.M.K.; Prakhov, S.N.; Price, J.W.; Starostin, A. [Univ. of California at Los Angeles, Los Angeles, CA (United States); Cherepnya, S.; Fil' kov, L.V.; Kashevarov, V.L. [Lebedev Physical Inst., Moscow (Russian Federation); Downie, E.J. [Univ. Mainz, Inst. fuer Kernphysik, Mainz (Germany); Univ. of Glasgow, Dept. of Physics and Astronomy, Glasgow (United Kingdom); Gregor, R.; Kotulla, M.; Lugert, S.; Metag, V.; Novotny, R. [Univ. Giessen, II. Physikalisches Inst., Giessen (Germany); Hornidge, D. [Mount Allison Univ., Sackville, NB (Canada); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Mekterovic, D.; Supek, I. [Rudjer Boskovic Inst., Zagreb (Croatia); Manley, D.M. [Kent State Univ., Kent, OH (United States); Sober, D. [The Catholic Univ. of America, Washington, D.C. (United States)

    2009-02-15

    A precise measurement of the Dalitz plot parameter, {alpha}, for the {eta}{yields}3{pi}{sup 0} decay is presented. The experiment was performed with the Crystal Ball and TAPS large-acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8.10{sup 6} {eta}{yields}3{pi}{sup 0} events were obtained, giving the result {alpha}=-0.032{+-}0.002{sub stat}{+-}0.002{sub syst}. (orig.)

  10. Purification, crystallization and preliminary crystallographic analysis of Streptococcus pyogenes laminin-binding protein Lbp

    Energy Technology Data Exchange (ETDEWEB)

    Linke, Christian, E-mail: clin180@ec.auckland.ac.nz [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Caradoc-Davies, Tom T. [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Australian Synchrotron, Clayton, Victoria 3168 (Australia); Proft, Thomas [School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand); Baker, Edward N. [School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland (New Zealand)

    2008-02-01

    The S. pyogenes laminin-binding protein Lbp, which is essential for adhesion to human laminin, has been expressed, purified and crystallized. The laminin-binding protein Lbp (Spy2007) from Streptococcus pyogenes (a group A streptococcus) mediates adhesion to the human basal lamina glycoprotein laminin. Accordingly, Lbp is essential in in vitro models of cell adhesion and invasion. However, the molecular and structural basis of laminin binding by bacteria remains unknown. Therefore, the lbp gene has been cloned for recombinant expression in Escherichia coli. Lbp has been purified and crystallized from 30%(w/v) PEG 1500 by the sitting-drop vapour-diffusion method. The crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 42.62, b = 92.16, c = 70.61 Å, β = 106.27°, and diffracted to 2.5 Å resolution.

  11. Expression, purification, crystallization and preliminary X-ray analysis of Pseudomonas aeruginosa AlgX

    Energy Technology Data Exchange (ETDEWEB)

    Weadge, J.T.; Robinson, H.; Yip, P. P.; Arnett, K.; Tipton, P. A.; Howell, P. L.

    2010-05-01

    AlgX is a periplasmic protein required for the production of the exopolysaccharide alginate in Pseudomonas sp. and Azotobacter vinelandii. AlgX has been overexpressed and purified and diffraction-quality crystals have been grown using iterative seeding and the hanging-drop vapor-diffusion method. The crystals grew as flat plates with unit-cell parameters a = 46.4, b = 120.6, c = 86.9 {angstrom}, {beta} = 95.7{sup o}. The crystals exhibited the symmetry of space group P2{sub 1} and diffracted to a minimum d-spacing of 2.1 {angstrom}. On the basis of the Matthews coefficient (V{sub M} = 2.25 {angstrom}{sup 3} Da{sup -1}), two molecules were estimated to be present in the asymmetric unit.

  12. Crystallization and preliminary X-ray diffraction analysis of the fructofuranosidase from Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Polo, Aitana; Linde, Dolores; Estévez, Marta; Fernández-Lobato, María; Sanz-Aparicio, Julia

    2010-11-01

    Xanthophyllomyces dendrorhous invertase is an extracellular enzyme that releases β-fructose from the nonreducing termini of various β-D-fructofuranoside substrates. Its ability to produce neokestose by transglycosylation makes this enzyme an interesting research target for applications in industrial biotechnology. The native enzyme, which is highly glycosylated, failed to crystallize. Therefore, it was submitted to EndoH deglycosylating treatment and crystals were grown by vapour-diffusion methods. The crystals belonged to space group P2(1)2(1)2, with unit-cell parameters a = 75.29, b = 204.93, c = 146.25 Å. Several diffraction data sets were collected using a synchrotron source. Self-rotation function and gel-filtration experiments suggested that the enzyme is a dimer with twofold symmetry.

  13. Harmonic Analysis in One-Parameter Metabelian Nilmanifolds

    Directory of Open Access Journals (Sweden)

    Amira Ghorbel

    2011-02-01

    Full Text Available Let G be a connected, simply connected one-parameter metabelian nilpotent Lie group, that means, the corresponding Lie algebra has a one-codimensional abelian subalgebra. In this article we show that G contains a discrete cocompact subgroup. Given a discrete cocompact subgroup Γ of G, we define the quasi-regular representation τ=ind_Γ^G 1 of G. The basic problem considered in this paper concerns the decomposition of τ into irreducibles. We give an orbital description of the spectrum, the multiplicity function and we construct an explicit intertwining operator between τ and its desintegration without considering multiplicities. Finally, unlike the Moore inductive algorithm for multiplicities on nilmanifolds, we carry out here a direct computation to get the multiplicity formula.

  14. Analysis of Self Screening Jammer Parameters with RADAR Equation

    Directory of Open Access Journals (Sweden)

    L.Surendra

    2014-03-01

    Full Text Available RADARs are mainly used to detect and locate the position of objects. The power received at the radar depends on the radiating power, object size, target material, shape of the target and channel noises due to atmosphere and external induced devices. In the war fields it is very important that the target identity is masked so that the enemy attacks can be overcome. In order to mask the targets and create the false identity jammers are very useful. There are various types of jammers and self screening jammers are the most protecting jammers. Hence we have analysed all the parameters related to self screening jammers. By calculating the range between target and the radar and observing the power transmitted by the source station and power received at the radar we have estimated the Cross over range. The variation of this cross over range with respect to jammer peak power, RADAR peak power, attenuation are analysed using matlab in this paper.

  15. Analysis of parameters for leachate treatment in a greenhouse system

    Directory of Open Access Journals (Sweden)

    Ana Laura Gómez Blasco

    2017-06-01

    Full Text Available In this paper is presented an approach for landfill leachate treatment using enhanced natural evaporation. Experimental set up considered using a greenhouse pilot prototype placed into the municipal landfill of Puebla city, México. The greenhouse was built with a basement surface enough to place 9 trays with leachate. Treatment follow up was done through the following parameters: air temperature inside and outside the greenhouse; leachate temperature at surface and middle liquid height. Results of the first set of experiments defined a minimal initial liquid height of 20% in respect to the tray height; the 2nd set allowed defining optimal evaporation rate conditions evaluated in respect of a tray placed outside, considered as reference of 100% efficiency (blank, obtained results showed that morning and night processes provided efficiencies up to 2 times the reference; otherwise, afternoon measurements showed similar temperature values inside and outside. In general collected data at winter season provided efficiencies between 82% and 147%, in periods of 24 h, it was observed that higher liquid reductions took place at North, and lower ones at the South positions. Based on these results it was proposed a 20 days experiment, using stagnant (E and recharge (R conditions referred to the blank (L, the R process showed greater efficiency (168% than the stagnant one (158%. Leachate chemical characterization indicates that pH is highly stable; while total solids, chemical oxygen demand, sulfate and chloride exhibit an increase in concentration reaching values of 1.2–2.5 times the initial concentration, phosphate was the only parameter exhibiting a decreasing trend ending with 40% of its initial concentration.

  16. Analysis on the Key Parameters of Aerospace Microminiaturization Decelerator

    Directory of Open Access Journals (Sweden)

    Xiangyang Jin

    2013-10-01

    Full Text Available A high efficiency special transmission decelerator is designed by scheme design, structural design, optimization design, and return difference analysis and computer simulation. Small teeth difference transmission with the first level bevel gear pair and the second level beveloid gear pair is adopted as the form of transmission in the decelerating system. Great torque and big bending moment are available by transmission ratio formula deduction, force analysis and strength analysis. The particle swarm optimization and the genetic algorithm have been combined and the mutation operator optimization model has been proposed to optimize the design of decelerator. Then the transmission with large transmission ratio, high torque, high power and high precision will be realized in small space. This model has solved the problems of particle swarm optimization in mechanical design. For example, there are more variables, it is constrained and it is easily precocious. This model has provided the theoretical basis for the optimum design of microminiaturization gear system.  

  17. An exploration of experimental parameters in the analysis of epoxy resin by reverse phase liquid chromatography.

    Science.gov (United States)

    Twichell, J E; Walker, J Q; Maynard, J B

    1979-05-01

    Reverse phase liquid chromatographic methods have been developed for the quality control of epoxy resin formulations. The results show that different formulations require different instrumental parameters for optimun separation and detection. Operating parameters required for the analysis of complex mixtures of epoxy resins, which include curing agents and diluents, are described in this paper. Parameters found to be critical are column temperature, solvent flow rate and gradient, and detector wavelength. Microprocessor parameters required to obtain reproducible data are also discussed.

  18. Analysis of ripple formation in single crystal spot welds

    Science.gov (United States)

    Rappaz, M.; Corrigan, D.; Boatner, L. A.

    1997-01-01

    Stationary spot welds have been made at the (001) surface of Fe-l5%Ni-15%Cr single crystals using a Gas Tungsten Arc (GTA). On the top surface of the spot welds, very regular and concentric ripples were observed after solidification by differential interference color microscopy. Their height (typically 1--5 micrometers and spacing, typically approximately 60 micrometers) decreased with the radius of the pool. These ripples were successfully accounted for in terms of capillary-wave theory using the fundamental mode frequency f(sub 0) given by the first zero of the zero-order Bessel function. The spacing d between the ripples was then equated to v(sub s)/f(sub 0), where v(sub s) is the solidification rate. From the measured ripple spacing, the velocity of the pool was deduced as a function of the radius, and this velocity was in good agreement with the results of a heat-flow simulation.

  19. Lifetime analysis of laser crystallized silicon films on glass

    Energy Technology Data Exchange (ETDEWEB)

    Kühnapfel, Sven; Amkreutz, Daniel; Gall, Stefan [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH - Institut Silizium-Photovoltaik, Berlin (Germany); Huang, Jialiang; Teal, Anthony; Kampwerth, Henner; Varlamov, Sergey [University of New South Wales, Sydney (Australia)

    2015-08-07

    Only recently, the quality of liquid phase crystallized silicon directly on glass substrates made a huge leap towards the quality of multi-crystalline wafers with open circuit voltages well above 600 mV. In this paper, we investigate the material quality in order to identify the factors limiting further performance improvements. We employ photoluminescence imaging on a state of the art test structure with lifetime calibration by transient photoluminescence. The resulting lifetime map is converted into an effective diffusion length map and the origin of regions with short lifetimes is investigated with electron backscattering and transmission electron microscopy. High local dislocation densities in areas with dissociated coincidence site lattice boundaries were found to be responsible for the localised quenching of the photoluminescence signal.

  20. Crystallization and preliminary X-ray analysis of l-methionine γ-lyase 1 from Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Dan [Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052 (Japan); Center for Integrated Medical Research, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Karaki, Tsuyoshi; Shimizu, Akira; Kamei, Kaeko; Harada, Shigeharu, E-mail: harada@kit.ac.jp [Graduate School of Science and Technology, Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Nozaki, Tomoyoshi [Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640 (Japan); Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052 (Japan)

    2008-08-01

    l-Methionine γ-lyase 1, a key enzyme in sulfur-containing amino-acid degradation, from the protozoan parasite E. histolytica was crystallized in a form suitable for X-ray structure analysis. l-Methionine γ-lyase (MGL) is a pyridoxal phosphate-dependent enzyme that is involved in the degradation of sulfur-containing amino acids. MGL is an attractive drug target against amoebiasis because the mammalian host of its causative agent Entamoeba histolytica lacks MGL. For the development of anti-amoebic agents based on the structure of MGL, one of two MGL isoenzymes (EhMGL1) was crystallized in the monoclinic space group P2{sub 1}, with unit-cell parameters a = 99.12, b = 85.38, c = 115.37 Å, β = 101.82°. The crystals diffract to beyond 2.0 Å resolution. The presence of a tetramer in the asymmetric unit (4 × 42.4 kDa) gives a Matthews coefficient of 2.8 Å{sup 3} Da{sup −1} and a solvent content of 56%. The structure was solved by the molecular-replacement method and structure refinement is now in progress.

  1. The SecB-like chaperone Rv1957 from Mycobacterium tuberculosis: crystallization and X-ray crystallographic analysis.

    Science.gov (United States)

    Lu, Zuokun; Wang, Han; Yu, TingTing

    2016-06-01

    Protein export is important in all bacteria, and bacteria have evolved specialized export machineries to fulfil this task. In Mycobacterium tuberculosis, the causative agent of tuberculosis, the general secretion pathway (Sec pathway) is conserved and is essential in performing the export of proteins. The bacterial Sec pathway post-translationally exports unfolded proteins out of the cytoplasm, and the core of the Sec pathway is composed of a heterotrimeric membrane-embedded channel, SecYEG, and two cytosolic components, SecA and SecB. SecB functions by stabilizing unfolded proteins, maintaining them in an export-competent state. Although SecB is mainly found in Proteobacteria, a SecB-like protein, Rv1957, that controls a stress-response toxin-antitoxin system, is found in M. tuberculosis. Rv1957 can also functionally replace the Escherichia coli SecB chaperone both in vivo and in vitro. In this work, the production, crystallization and X-ray crystallographic analysis of Rv1957 are reported. Notably, diffraction-quality crystals were obtained only at high concentrations of dimethyl sulfoxide, i.e. about 12%(v/v). The crystals of Rv1957 belonged to space group P212121, with unit-cell parameters a = 64.5, b = 92.0, c = 115.4 Å.

  2. Optimisation of shock absorber process parameters using failure mode and effect analysis and genetic algorithm

    Science.gov (United States)

    Mariajayaprakash, Arokiasamy; Senthilvelan, Thiyagarajan; Vivekananthan, Krishnapillai Ponnambal

    2013-07-01

    The various process parameters affecting the quality characteristics of the shock absorber during the process were identified using the Ishikawa diagram and by failure mode and effect analysis. The identified process parameters are welding process parameters (squeeze, heat control, wheel speed, and air pressure), damper sealing process parameters (load, hydraulic pressure, air pressure, and fixture height), washing process parameters (total alkalinity, temperature, pH value of rinsing water, and timing), and painting process parameters (flowability, coating thickness, pointage, and temperature). In this paper, the process parameters, namely, painting and washing process parameters, are optimized by Taguchi method. Though the defects are reasonably minimized by Taguchi method, in order to achieve zero defects during the processes, genetic algorithm technique is applied on the optimized parameters obtained by Taguchi method.

  3. Sensitivity analysis on parameters and processes affecting vapor intrusion risk

    NARCIS (Netherlands)

    Picone, S.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2012-01-01

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the v

  4. Axion Crystals

    CERN Document Server

    Ozaki, Sho

    2016-01-01

    The low-energy effective theories for gapped insulators are classified by three parameters: permittivity $\\epsilon$, permeability $\\mu$, and theta angle $\\theta$. Crystals with periodic $\\epsilon$ are known as photonic crystals. We here study the band structure of photons in a new type of crystals with periodic $\\theta$ (modulo $2\\pi$) in space, which we call the axion crystals. We find that the axion crystals have a number of new properties that the usual photonic crystals do not possess, such as the helicity-dependent photonic band gaps and the nonrelativistic gapless dispersion relation at small momentum. We briefly discuss possible realizations of axion crystals in condensed matter systems as well as high-energy physics.

  5. Crystallization and preliminary X-ray diffraction analysis of red clover necrotic mosaic virus

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stanton L.; Guenther, Richard H.; Sit, Tim L.; Swartz, Paul D.; Meilleur, Flora; Lommel, Steven A.; Rose, Robert B. (NCSU)

    2010-11-12

    Red clover necrotic mosaic virus (RCNMV) is a species that belongs to the Tombusviridae family of plant viruses with a T = 3 icosahedral capsid. RCNMV virions were purified and were crystallized for X-ray analysis using the hanging-drop vapor-diffusion method. Self-rotation functions and systematic absences identified the space group as I23, with two virions in the unit cell. The crystals diffracted to better than 4 {angstrom} resolution but were very radiation-sensitive, causing rapid decay of the high-resolution reflections. The data were processed to 6 {angstrom} in the analysis presented here.

  6. Crystallization and preliminary X-ray crystallographic analysis of yeast NAD{sup +}-specific isocitrate dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Gang [Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States); Taylor, Alexander B. [Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States); X-ray Crystallography Core Laboratory, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States); McAlister-Henn, Lee [Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States); Hart, P. John, E-mail: pjhart@biochem.uthscsa.edu [Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States); X-ray Crystallography Core Laboratory, University of Texas Health Science Center, San Antonio, TX 78229-3900 (United States)

    2005-05-01

    Yeast NAD{sup +}-isocitrate dehydrogenase has been purified and crystallized using sodium citrate, a competitive inhibitor of the enzyme, as a precipitant. Preliminary X-ray analyses indicate the molecular boundaries of the molecule and large continuous solvent channels in the crystal. NAD{sup +}-specific isocitrate dehydrogenase (IDH; EC 1.1.1.41) is a complex allosterically regulated enzyme in the tricarboxylic acid cycle. Yeast IDH is believed to be an octamer containing four catalytic IDH2 and four regulatory IDH1 subunits. Crystals of yeast IDH have been obtained and optimized using sodium citrate, a competitive inhibitor of the enzyme, as the precipitating agent. The crystals belong to space group R3, with unit-cell parameters a = 302.0, c = 112.1 Å. Diffraction data were collected to 2.9 Å from a native crystal and to 4.0 Å using multiwavelength anomalous diffraction (MAD) methods from an osmium derivative. Initial electron-density maps reveal large solvent channels and the molecular boundaries of the allosteric IDH multimer.

  7. Crystallization and preliminary crystallographic analysis of hygromycin B phosphotransferase from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Iino, Daisuke [Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502 (Japan); Takakura, Yasuaki [Division of Integrative Environmental Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572 (Japan); Kuroiwa, Mika; Kawakami, Ryouta; Sasaki, Yasuyuki [Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502 (Japan); Hoshino, Takayuki [Division of Integrative Environmental Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572 (Japan); Ohsawa, Kanju [Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502 (Japan); Nakamura, Akira [Division of Integrative Environmental Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572 (Japan); Yajima, Shunsuke, E-mail: yshun@nodai.ac.jp [Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502 (Japan)

    2007-08-01

    The crystallization and preliminary X-ray studies of the aminoglycoside antibiotic-modifying enzyme hygromycin B phosphotransferase from E. coli are reported. Aminoglycoside antibiotics, such as hygromycin, kanamycin, neomycin, spectinomycin and streptomycin, inhibit protein synthesis by acting on bacterial and eukaryotic ribosomes. Hygromycin B phosphotransferase (Hph; EC 2.7.1.119) converts hygromycin B to 7′′-O-phosphohygromycin using a phosphate moiety from ATP, resulting in the loss of its cell-killing activity. The Hph protein has been crystallized for the first time using a thermostable mutant and the hanging-drop vapour-diffusion method. The crystal provided diffraction data to a resolution of 2.1 Å and belongs to space group P3{sub 2}21, with unit-cell parameters a = b = 71.0, c = 125.0 Å. Crystals of complexes of Hph with hygromycin B and AMP-PNP or ADP have also been obtained in the same crystal form as that of the apoprotein.

  8. ReSe2: a reassessment of crystal structure and thermal analysis

    Science.gov (United States)

    Jariwala, Bhakti; Thamizhavel, Arumugum; Bhattacharya, Arnab

    2017-02-01

    The rhenium-based layered dichalcogenide ReSe2 crystallizes in a distorted triclinic structure which results in unique, anisotropic electronic and optical properties. This, along with a weak layer-dependence of band gap has made ReSe2 a subject of intense contemporary research interest. However, there has been no agreement on the exact crystal structure of this material, or knowledge of its thermal properties like the melting point. In this work, we perform single crystal, Laue, and powder diffraction measurements on high-quality ReSe2 crystals synthesized using a modified Bridgman technique. We confirm the presence of triclinic symmetry (P\\bar{1} -space group) and support the view that that ReSe2 has a distorted CdCl2-type structure (rather than Cd(OH)2 as initially proposed) and obtain lattice parameter values of a  =  6.5791(8) Å, b  =  6.6897(10) Å, and c  =  6.7013(11) Å. Further, thermal measurements on these crystals show a clear endothermic peak at around 1115 °C pointing to a melting transition, and show no other phase transitions up to 1300 °C.

  9. Crystallization Behavior and Microstructural Analysis of Strontium Rich (PbSr−TiO Glass Ceramics in Presence of LaO

    Directory of Open Access Journals (Sweden)

    C. R. Gautam

    2011-01-01

    Full Text Available Crystallization and microstructural behavior of various strontium-rich glass ceramics in the system 65[(PbxSr1−xTiO3]-24[2SiO2⋅B2O3]-5[BaO]-5[K2O]-1[La2O3] (0.0≤≤0.4 with addition of 1% La2O3 have been investigated. The addition of La2O3 has been found to play an important role in crystallization of perovskite (Pb,SrTiO3 as a solid solution phase. Also, it causes a change in the surface morphology of the fined crystallites of the major phase. Differential thermal analysis (DTA shows only one exothermic crystallization peak, which shifts towards higher temperature with increasing amount of strontium oxide. Glasses were subjected to various heat treatment schedules for the crystallization. Very good crystallization of strontium-rich glass compositions is observed. X-ray diffraction studies confirm that cubic perovskite lead strontium titanate crystallizes as major phase. Lattice parameter decreases with increasing strontium content similar to lead strontium titanate ceramics. Uniform and interconnected crystallites are dispersed in glassy matrix.

  10. Crystallization and X-ray diffraction analysis of the Trp/amber editing site of hepatitis delta virus (+)RNA: a case of rational design

    Energy Technology Data Exchange (ETDEWEB)

    MacElrevey, Celeste; Wedekind, Joseph E., E-mail: joseph-wedekind@urmc.rochester.edu [Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642 (United States)

    2005-12-01

    Well diffracting decamer crystals of the hepatitis delta virus RNA-editing site were prepared, but exhibited merohedral twinning and base averaging owing to duplex symmetry. A longer asymmetric construct that includes additional flanking RNA sequences has been crystallized that does not appear to exhibit these defects. RNA editing by mammalian ADAR1 (Adenosine Deaminase Acting on RNA) is required for the life cycle of the hepatitis delta virus (HDV). Editing extends the single viral open reading frame to yield two protein products of alternate length. ADARs are believed to recognize double-stranded RNA substrates via a ‘structure-based’ readout mechanism. Crystals of 10-mer duplexes representing the HDV RNA-editing site diffracted to 1.35 Å resolution, but suffered from merohedral twinning and averaging of the base registry. Expansion of the construct to include two flanking 3 × 1 internal loops yielded crystals in the primitive tetragonal space group P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2. X-ray diffraction data were collected to 2.8 Å resolution, revealing a unit cell with parameters a = 62.5, c = 63.5 Å. The crystallization and X-ray analysis of multiple forms of the HDV RNA-editing substrate, encounters with common RNA crystal-growth defects and a strategy to overcome these problems are reported.

  11. Effect of size discrepancy of. gamma. - and. gamma. '-phases crystal lattice parameters on heat resisting dispersion hardening nickel alloys

    Energy Technology Data Exchange (ETDEWEB)

    Petrushin, N.V.; Ignatova, I.A.; Logunov, A.V.; Samojlov, A.I.; Razumovskij, I.M.

    Effect of Cr, Co, Nb and W alloying elements on crystal lattice parameters of ..gamma.. ahd ..gamma..' phases in Ni-Cr-Co-W-Al-Ti- Nb-Hf alloys and on their dimensional misfit at 293 and 1173 K is studied. Alloying at which alloys have the parameter of ..gamma..-solid solution lattice less than that of ..gamma..'-phase results in low heat-resistant properties and in considerable difference of coefficients of thermal expansion of the phases. Definite positive misfit of ..gamma..- and ..gamma..'-phase lattices and a low temperature gradient are the conditions of high heat resistance of complex-alloyed nickel alloys. Possible mechanisms of lattice misfit effect on strength and coalescence kinetics of the second phase in heterogeneous alloys at high temperatures are discussed.

  12. Sperm penetration assay and its correlation with semen analysis parameters

    Directory of Open Access Journals (Sweden)

    Laxmi Kant Pandey

    2015-11-01

    Full Text Available Background: Aim of current study was to determine whether the Sperm Penetration Assay (SPA can be used as a test to discriminate the infertile male from fertile one. We have also correlated the SPA with semen analysis. Methods: Sperm characteristics namely Semen analysis and the sperm penetration assay were tested in 44 infertile and 10 fertile men. Sperm penetration assay was determined by using zona free hamster eggs. Results: With decreasing spermatozoa concentration in the semen there was significant decrease in percentage penetration of zona free Hamster eggs (p0.05. Conclusions: The Sperm penetration assay could discriminate the infertile group from fertile group significantly (p<0.001. The test appeared to be highly reproducible and probably identifies a truly infertile male. [Int J Res Med Sci 2015; 3(11.000: 3197-3201

  13. Structural parameters of young star clusters: fractal analysis

    Science.gov (United States)

    Hetem, A.

    2017-07-01

    A unified view of star formation in the Universe demand detailed and in-depth studies of young star clusters. This work is related to our previous study of fractal statistics estimated for a sample of young stellar clusters (Gregorio-Hetem et al. 2015, MNRAS 448, 2504). The structural properties can lead to significant conclusions about the early stages of cluster formation: 1) virial conditions can be used to distinguish warm collapsed; 2) bound or unbound behaviour can lead to conclusions about expansion; and 3) fractal statistics are correlated to the dynamical evolution and age. The technique of error bars estimation most used in the literature is to adopt inferential methods (like bootstrap) to estimate deviation and variance, which are valid only for an artificially generated cluster. In this paper, we expanded the number of studied clusters, in order to enhance the investigation of the cluster properties and dynamic evolution. The structural parameters were compared with fractal statistics and reveal that the clusters radial density profile show a tendency of the mean separation of the stars increase with the average surface density. The sample can be divided into two groups showing different dynamic behaviour, but they have the same dynamic evolution, since the entire sample was revealed as being expanding objects, for which the substructures do not seem to have been completely erased. These results are in agreement with the simulations adopting low surface densities and supervirial conditions.

  14. Parameter Calibration and Numerical Analysis of Twin Shallow Tunnels

    Science.gov (United States)

    Paternesi, Alessandra; Schweiger, Helmut F.; Scarpelli, Giuseppe

    2017-05-01

    Prediction of displacements and lining stresses in underground openings represents a challenging task. The main reason is primarily related to the complexity of this ground-structure interaction problem and secondly to the difficulties in obtaining a reliable geotechnical characterisation of the soil or the rock. In any case, especially when class A predictions fail in forecasting the system behaviour, performing class B or C predictions, which rely on a higher level of knowledge of the surrounding ground, can represent a useful resource for identifying and reducing model deficiencies. The case study presented in this paper deals with the construction works of twin-tube shallow tunnels excavated in a stiff and fine-grained deposit. The work initially focuses on the ground parameter calibration against experimental data, which together with the choice of an appropriate constitutive model plays a major role in the assessment of tunnelling-induced deformations. Since two-dimensional analyses imply initial assumptions to take into account the effect of the 3D excavation, three-dimensional finite element analyses were preferred. Comparisons between monitoring data and results of numerical simulations are provided. The available field data include displacements and deformation measurements regarding both the ground and tunnel lining.

  15. Analysis of physical and chemical parameters of bottled drinking water.

    Science.gov (United States)

    Mahajan, Rakesh Kumar; Walia, T P S; Lark, B S; Sumanjit

    2006-04-01

    Seventeen different brands of bottled drinking water, collected from different retail shops in Amritsar, were analyzed for different physical and chemical parameters to ascertain their compliability with the prescribed/recommended limits of the World Heath Organization (WHO) and the United States Environmental Protection Agency (USEPA). It was found that the majority of the brands tested were over-treated. Lower values of hardness, total dissolved solids (TDS) and conductance than the prescribed limits of WHO showed that water was deficient in essential minerals. Minerals like magnesium, potassium, calcium and fluoride were present in some cases in such a low concentration that water seemed to be as good as distilled water. Samples showing fluoride lesser than 0.5 mg/l warranted additional sources of fluoride for the people consuming only bottled water for drinking purposes. Zero values for chlorine demand as shown by all the bottled water samples showed that water samples were safe from micro-organisms. In case of heavy metals, only lead had been found to be greater than the limit of 0.015 mg/l as prescribed by WHO and USEPA, in seven out of 17 samples. Lead even at such a low concentration can pose a great health hazard.

  16. Analysis of the Epididymal Sperm Parameters in Fertile Men

    Institute of Scientific and Technical Information of China (English)

    文任乾; 李世勤; 王春湘; 王庆辉; 李庆琨; 冯焕民; 姜彦嘉; 张信烈

    1994-01-01

    The left and right epididymial fluids from 73 normal fertile men were respectively eollected by eannulating the yes deferens during the operation of vasectomy. The parameters of epididymal spermatozoa were analysed. The results indicated that the sperm motility( % ), normal sperm morphology(%), sperm viability(%) and hypoosmotie swelling test (HOST) ( % ) were within the normal range as compared with those in the ejaculated spermatozoa. However, the sperm concentration in epididymis (6220.6± 5300.8 million per ml) was higher than that in semen. It is of interest that the sperm concentration in the right epidymis was significantly higher than that in the left.It was also demonstrated that the percentage of abnormal Kremer's test in the left epididymal spermatozoa was significantly higher than that in the right. The above phenomenon was discussed. There was no anti-sperm antibody on the surface of spermatozoa from epididymis as determined by the sperm cervical mucus contact test (SCMC) and lmmunobead test (IBT). These data will be usefull for the research of male reproductive physiology3,, male contracecetive and vasectomy.

  17. ASPM2: Progress Toward the Analysis of Symbolic Parameter Models

    Science.gov (United States)

    1994-09-01

    PAGE fr’..I oNS No.07408 wwOic .tgaflmq bwg #’n for INt (o~ft"Oo of information is estiffateo to a e, W~u mr tuueoe Whom W, Vue Jw for IrwSwWg...lFor XTIS QLanlDTIC TAB Unannounoed Justification_ By1Distrbut Avai lab i 1jt.y Codes Dist h : L O Y L A TD I 1h Running head: ANALYSIS OF SYMBOLIC

  18. Crystal Data

    Science.gov (United States)

    SRD 3 NIST Crystal Data (PC database for purchase)   NIST Crystal Data contains chemical, physical, and crystallographic information useful to characterize more than 237,671 inorganic and organic crystalline materials. The data include the standard cell parameters, cell volume, space group number and symbol, calculated density, chemical formula, chemical name, and classification by chemical type.

  19. Nanoemulsion-based delivery systems for poorly water-soluble bioactive compounds: Influence of formulation parameters on Polymethoxyflavone crystallization.

    Science.gov (United States)

    Li, Yan; Zheng, Jinkai; Xiao, Hang; McClements, David Julian

    2012-06-01

    Polymethoxyflavones (PMFs) extracted from citrus peel exhibit potent anti-cancer activity, but are highly hydrophobic molecules with poor solubility in both water and oil at ambient and body temperature, which limits their bioavailability. The possibility of encapsulating PMFs within nanoemulsion-based delivery systems to facilitate their application in nutraceutical and pharmaceutical products was investigated. The influence of oil type (corn oil, MCT, orange oil), emulsifier type (β-lactoglobulin, lyso-lecithin, Tween, and DTAB), and neutral cosolvents (glycerol and ethanol) on the formation and stability of PMF-loaded nanoemulsions was examined. Nanoemulsions (r emulsifier types, except DTAB. Lipid droplet charge could be altered from highly cationic (DTAB), to near neutral (Tween), to highly anionic (β-lactoglobulin, lyso-lecithin) by varying emulsifier type. PMF crystals formed in all nanoemulsions after preparation, which had a tendency to sediment during storage. The size, morphology, and aggregation of PMF crystals depended on preparation method, emulsifier type, oil type, and cosolvent addition. These results have important implications for the development of delivery systems for bioactive components that have poor oil and water solubility at application temperatures.

  20. Dependence of gain and phase-shift on crystal parameters and pump intensity in unidirectional photorefractive ring resonators

    Indian Academy of Sciences (India)

    M K Maurya; T K Yadav; R A Yadav

    2009-04-01

    The steady-state amplification of light beam during two-wave mixing in photorefractive materials has been analysed in the strong nonlinear regime. The oscillation conditions for unidirectional ring resonator have been studied. The signal beam can be amplified in the presence of material absorption, provided the gain due to the beam coupling is large enough to overcome the cavity losses. Such amplification is responsible for the oscillations. The gain bandwidth is only a few Hz. In spite of such an extremely narrow bandwidth, unidirectional oscillation can be observed easily at any cavity length in ring resonators by using photorefractive crystals as the medium and this can be explained in terms of the photorefractive phase-shift. The presence of such a phase-shift allows the possibility of the non-reciprocal steady-state transfer of energy between the two light beams. Dependence of gain bandwidth on coupling constant, absorption coefficient of the material's cavity length (crystal length) and modulation ratio have also been studied.

  1. Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Maskaly, Karlene Rosera [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2005-06-01

    increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.

  2. Multiscale Analysis of Structurally-Graded Microstructures Using Molecular Dynamics, Discrete Dislocation Dynamics and Continuum Crystal Plasticity

    Science.gov (United States)

    Saether, Erik; Hochhalter, Jacob D.; Glaessgen, Edward H.; Mishin, Yuri

    2014-01-01

    A multiscale modeling methodology is developed for structurally-graded material microstructures. Molecular dynamic (MD) simulations are performed at the nanoscale to determine fundamental failure mechanisms and quantify material constitutive parameters. These parameters are used to calibrate material processes at the mesoscale using discrete dislocation dynamics (DD). Different grain boundary interactions with dislocations are analyzed using DD to predict grain-size dependent stress-strain behavior. These relationships are mapped into crystal plasticity (CP) parameters to develop a computationally efficient finite element-based DD/CP model for continuum-level simulations and complete the multiscale analysis by predicting the behavior of macroscopic physical specimens. The present analysis is focused on simulating the behavior of a graded microstructure in which grain sizes are on the order of nanometers in the exterior region and transition to larger, multi-micron size in the interior domain. This microstructural configuration has been shown to offer improved mechanical properties over homogeneous coarse-grained materials by increasing yield stress while maintaining ductility. Various mesoscopic polycrystal models of structurally-graded microstructures are generated, analyzed and used as a benchmark for comparison between multiscale DD/CP model and DD predictions. A final series of simulations utilize the DD/CP analysis method exclusively to study macroscopic models that cannot be analyzed by MD or DD methods alone due to the model size.

  3. Analysis of the operating parameters of a vortex electrostatic precipitator

    Science.gov (United States)

    Congxiang, Lu; Chengwu, Yi; Rongjie, Yi; Shiwen, Liu

    2017-02-01

    A vortex electrostatic precipitator (VEP) forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that: when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry (PIV), the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.

  4. Analysis of the operating parameters of a vortex electrostatic precipitator

    Science.gov (United States)

    Lu, Congxiang; Yi, Chengwu; Yi, Rongjie; Liu, Shiwen

    2017-02-01

    A vortex electrostatic precipitator (VEP) forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that: when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry (PIV), the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.

  5. Crystal-field analysis for RE 3+ ions in laser materials: II. Absorption spectra and energy levels calculations for Nd 3+ ions doped into SrLaGa 3O 7 and BaLaGa 3O 7 crystals and Tm 3+ ions in SrGdGa 3O 7

    Science.gov (United States)

    Karbowiak, M.; Gnutek, P.; Rudowicz, C.; Ryba-Romanowski, W.

    2011-08-01

    Low temperature polarized absorption spectra are analyzed to achieve assignments of energy levels for Nd 3+ and Tm 3+ ions at monoclinic C s site symmetry in ABC 3O 7 crystals. Based on the concept of average optical center, the experimental energy levels for single crystals of SrLaGa 3O 7:Nd 3+ (SLG:Nd), BaLaGa 3O 7:Nd 3+ (BLG:Nd), and SrGdGa 3O 7:Tm 3+ (SGG:Tm) were analyzed in terms of the free-ion parameters and the crystal field (CF) ones, B kq. Assignments of the energy levels resolved in the spectra were done in stages applying the ascent/descent in symmetry method in CF analysis. The actual monoclinic C s site symmetry at the metal centers in ABC 3O 7 crystals and the approximated orthorhombic C 2v and tetragonal C 4v symmetry were considered. The starting values of B kq's for SLG:Nd and BLG:Nd crystals were obtained from superposition model (SPM) analysis. The final fitted crystal field parameters show high compatibility with the existing data for structurally similar ion-host systems. The obtained values of the intrinsic parameters provide basis for SPM analysis of CF parameters for rare earth ions in other similar systems, especially those exhibiting low-symmetry sites. The SPM parameters derived for SLG:Nd are used for simulation and assignment of the energy levels involved in the potential laser transitions at about 1800 nm due to Tm 3+ ions in SGG crystals. The evaluated emission cross-section is about two times lower than that obtained previously.

  6. First Principles Calculation of Structural Parameters of Si Crystal%Si晶体结构参数的第一性原理计算

    Institute of Scientific and Technical Information of China (English)

    林传金; 郭莉莉

    2013-01-01

    The total energy of Si crystal were calculated in different lattice constant by first principles, which based on the density functional theory. The calculated data were gotten by the Birch-Muranghan third-order equation, then the related parameters were obtained. The Si crystal’s specific form of Birch-Muranghan third equation was also deduced with these parameters. The lattice constant and elastic modulus of Si crystal in the steady state were also calculated, which were quite consistent with the experimental values.%本文采用基于密度泛函理论的第一性原理计算不同晶格常数下 Si 晶体的总能,用计算所得出的数据通过 Brich-Muranghan三阶状态方程进行拟合得到相关的参数,获得 Si晶体的 Brich-Muranghan三阶状态方程具体形式,并通过计算获得Si在稳定状态下的晶格常数和体弹性模量,结果与实验数值相符。

  7. Dislocation Analysis for Large-sized Sapphire Single Crystal Grown by SAPMAC Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, large-sized sapphire (Φ230×210 mm, 27.5 kg) was grown by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at the cooled center). Dislocation peculiarity in large sapphire boule (0001) basal plane was investigated by chemical etching, scanning electron microscopy and X-ray topography method. The triangular dislocation etch pit measured is 7.6×101~8.0×102 cm-2, in which relative high-density dislocations were generated at both initial and final stages of crystal growth. The analysis of single-crystal X-ray topography shows that there are no apparent sub-grain boundaries; the dislocation lines are isolated and straight. Finally, the origins of low-density dislocation in sapphire crystal are discussed by numerical analysis method.

  8. ANALYSIS OF THE FUNDAMENTAL CHARACTERISTICS OF DIAMOND-LIKE CRYSTALS AND LOW-DIMENSIONAL STRUCTURES

    Directory of Open Access Journals (Sweden)

    V.G.Litovchenko

    2004-01-01

    Full Text Available The principle has been developed for systematizing the diamond-like crystals with tetrahedral structure of the elementary cells and with valence chemical bonds, based on the calculation of the lattice constant. The approach proposed permits to predict basic parameters such as energy gap Eg, electron affinity (optical work function X, mechanical hardness H, melting temperature Tm, optical phonon frequency etc. These parameters have been calculated and the table is presented for a number of chemical compositions. For materials with mixed chemical bonds (valence and ionic the corrections can be calculated using Pouling electronegativity conception. The comparison with experiment demonstrates good agreement between the latter and the proposed procedure.

  9. Mathematical modeling and fuzzy availability analysis for serial processes in the crystallization system of a sugar plant

    Science.gov (United States)

    Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram

    2017-08-01

    The binary states, i.e., success or failed state assumptions used in conventional reliability are inappropriate for reliability analysis of complex industrial systems due to lack of sufficient probabilistic information. For large complex systems, the uncertainty of each individual parameter enhances the uncertainty of the system reliability. In this paper, the concept of fuzzy reliability has been used for reliability analysis of the system, and the effect of coverage factor, failure and repair rates of subsystems on fuzzy availability for fault-tolerant crystallization system of sugar plant is analyzed. Mathematical modeling of the system is carried out using the mnemonic rule to derive Chapman-Kolmogorov differential equations. These governing differential equations are solved with Runge-Kutta fourth-order method.

  10. Mathematical modeling and fuzzy availability analysis for serial processes in the crystallization system of a sugar plant

    Science.gov (United States)

    Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram

    2016-08-01

    The binary states, i.e., success or failed state assumptions used in conventional reliability are inappropriate for reliability analysis of complex industrial systems due to lack of sufficient probabilistic information. For large complex systems, the uncertainty of each individual parameter enhances the uncertainty of the system reliability. In this paper, the concept of fuzzy reliability has been used for reliability analysis of the system, and the effect of coverage factor, failure and repair rates of subsystems on fuzzy availability for fault-tolerant crystallization system of sugar plant is analyzed. Mathematical modeling of the system is carried out using the mnemonic rule to derive Chapman-Kolmogorov differential equations. These governing differential equations are solved with Runge-Kutta fourth-order method.

  11. Large Scale DD Simulation Results for Crystal Plasticity Parameters in Fe-Cr And Fe-Ni Systems

    Energy Technology Data Exchange (ETDEWEB)

    Zbib, Hussein M.; Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.

    2012-04-30

    The development of viable nuclear energy source depends on ensuring structural materials integrity. Structural materials in nuclear reactors will operate in harsh radiation conditions coupled with high level hydrogen and helium production, as well as formation of high density of point defects and defect clusters, and thus will experience severe degradation of mechanical properties. Therefore, the main objective of this work is to develop a capability that predicts aging behavior and in-service lifetime of nuclear reactor components and, thus provide an instrumental tool for tailoring materials design and development for application in future nuclear reactor technologies. Towards this end goal, the long term effort is to develop a physically based multiscale modeling hierarchy, validated and verified, to address outstanding questions regarding the effects of irradiation on materials microstructure and mechanical properties during extended service in the fission and fusion environments. The focus of the current investigation is on modern steels for use in nuclear reactors including high strength ferritic-martensitic steels (Fe-Cr-Ni alloys). The effort is to develop a predicative capability for the influence of irradiation on mechanical behavior. Irradiation hardening is related to structural information crossing different length scales, such as composition, dislocation, and crystal orientation distribution. To predict effective hardening, the influence factors along different length scales should be considered. Therefore, a hierarchical upscaling methodology is implemented in this work in which relevant information is passed between models at three scales, namely, from molecular dynamics to dislocation dynamics to dislocation-based crystal plasticity. The molecular dynamics (MD) was used to predict the dislocation mobility in body centered cubic (bcc) Fe and its Ni and Cr alloys. The results are then passed on to dislocation dynamics to predict the critical resolved

  12. Photocurrent analysis of AgIn$_5$S$_8$ crystal

    Indian Academy of Sciences (India)

    MAHMUT BUCURGAT; SELAHATTIN OZDEMIR; TEZER FIRAT

    2016-10-01

    The photocurrent (PC) spectrum of AgIn$_5$S$_8$ crystal consists of a single peak, which provides to determine the bandgap energy by applying the Moss rule. The temperature dependence of the bandgap energy was alsocalculated. The PC dramatically increased by pre-illumination with light having wavelength corresponding to the bandgap of AgIn$_5$S$_8$. The temperature-dependent PC of the sample was measured at different temperatures from80 to 300 K and the PC spectrum consisted a single broad peak. Thermal quenching of the PC was observed to start at $\\sim$105 K and the PC completely quenched at $\\sim$180 K. The quenching mechanism was discussed in terms of the two-centre model. The height of the PC peak rised linearly with applied voltage up to 5.0 V under constant intensity of light. Similarly, the dark current–voltage characteristics consisted of a single region dominating an ohmicbehaviour, and no space charge limited region was apparent at various temperatures up to 20 V.

  13. Expression, purification, crystallization, and preliminary X-ray crystallographic analysis of OXA-17, an extended-spectrum {beta}-lactamase conferring severe antibiotic resistance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H., E-mail: msgjhlee@mju.ac.kr; Sohn, S. G., E-mail: sgsohn@mju.ac.kr; Jung, H. I., E-mail: jhinumber1@hanmail.net; An, Y. J., E-mail: anyj0120@hanmail.net; Lee, S. H., E-mail: sangheelee@mju.ac.kr [Myongji University, Drug Resistance Proteomics Laboratory, Department of Biological Sciences (Korea, Republic of)

    2013-07-15

    OXA-17, an extended-spectrum {beta}-lactamase (ESBL) conferring severe antibiotic resistance, hydrolytically inactivates {beta}-lactam antibiotics, inducing a lack of eradication of pathogenic bacteria by oxyimino {beta}-lactams and not helping hospital infection control. Thus, the enzyme is a potential target for developing antimicrobial agents against pathogens producing ESBLs. OXA-17 was purified and crystallized at 298 K. X-ray diffraction data from OXA-17 crystal have been collected to 1.85 A resolution using synchrotron radiation. The crystal of OXA-17 belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 48.37, b = 101.12, and c = 126.07 A. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 54.6%.

  14. Purification, crystallization and preliminary X-ray diffraction analysis of the CBS-domain pair from the Methanococcus jannaschii protein MJ0100

    Science.gov (United States)

    Lucas, María; Kortazar, Danel; Astigarraga, Egoitz; Fernández, José A.; Mato, Jose M.; Martínez-Chantar, María Luz; Martínez-Cruz, Luis Alfonso

    2008-01-01

    CBS domains are small protein motifs consisting of a three-stranded β-sheet and two α-helices that are present in proteins of all kingdoms of life and in proteins with completely different functions. Several genetic diseases in humans have been associated with mutations in their sequence, which has made them promising targets for rational drug design. The C-terminal domain of the Methanococcus jannaschii protein MJ0100 includes a CBS-domain pair and has been overexpressed, purified and crystallized. Crystals of selenomethionine-substituted (SeMet) protein were also grown. The space group of both the native and SeMet crystals was determined to be orthorhombic P212121, with unit-cell parameters a = 80.9, b = 119.5, c = 173.3 Å. Preliminary analysis of the X-ray data indicated that there were eight molecules per asymmetric unit in both cases. PMID:18931440

  15. Expression, purification, crystallization, and preliminary X-ray crystallographic analysis of OXA-17, an extended-spectrum β-lactamase conferring severe antibiotic resistance

    Science.gov (United States)

    Lee, J. H.; Sohn, S. G.; Jung, H. I.; An, Y. J.; Lee, S. H.

    2013-07-01

    OXA-17, an extended-spectrum β-lactamase (ESBL) conferring severe antibiotic resistance, hydrolytically inactivates β-lactam antibiotics, inducing a lack of eradication of pathogenic bacteria by oxyimino β-lactams and not helping hospital infection control. Thus, the enzyme is a potential target for developing antimicrobial agents against pathogens producing ESBLs. OXA-17 was purified and crystallized at 298 K. X-ray diffraction data from OXA-17 crystal have been collected to 1.85 Å resolution using synchrotron radiation. The crystal of OXA-17 belongs to space group P212121, with unit-cell parameters a = 48.37, b = 101.12, and c = 126.07 Å. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 54.6%.

  16. The fractal method of the lunar surface parameters analysis

    Science.gov (United States)

    Nefedev, Yuri; Demina, Natalia; Petrova, Natalia; Demin, Sergey; Andreev, Alexey

    2016-10-01

    Analysis of complex selenographic systems is a complicated issue. This fully applies to the lunar topography. In this report a new method of the comparative reliable estimation of the lunar maps data is represented. The estimation was made by the comparison of high-altitude lines using the fractal analysis. The influence of the lunar macrofigure variances were determined by the method of fractal dimensions comparison.By now the highly accurate theories of the lunar movement have been obtained and stars coordinates have been determined on the basis of space measurements with the several mas accuracy but there are factors highly influencingon the accuracy of the results of these observations. They are: exactitude of the occultation moment recording, errors of the stars coordinates, accuracy of lunar ephemeris positions and unreliability of lunar marginal zone maps. Existing charts of the lunar marginal zone have some defects. To resolve this task thecomparison method in which the structure of the high-altitude lines of data appropriated with identical lunar coordinates can use. However, such comparison requires a lot of calculations.In order to find the variations of irregularities for the limb points above the mean level of lunar surface were computed the position angles of this points P and D by Hayn' coordinates. Thus the data of our studies was obtained by identical types.Then the first, segments of a lunar marginal zone for every 45" on P were considered. For each segment profile of the surface for a constant D were constructed with a step of 2". Thus 80 profiles were obtained. Secondly the fractal dimensions d for each considered structure was defined. Third the obtained values d were compared with the others maps considered in this work.The obtained results show some well agreement between the mean fractal dimensions for maps. Thus it can be concluded that the using of fractal method for lunar maps analysis to determine the accuracy of the presented to

  17. Influences of processing parameters on microstructure during investment casting of nickel-base single crystal superalloy DD3

    Directory of Open Access Journals (Sweden)

    Gao Sifeng

    2012-05-01

    Full Text Available The effects of solidification variables on the as-cast microstructures of nickel-base single crystal superalloy DD3 have been investigated by using the modified Bridgman apparatus. The experiments were performed under a thermal gradient of approximately 45 K·cm-1 and at withdrawal rates ranging from 30 to 200 m·s-1. The experimental results show that the primary and secondary dendritic arm spacings (PDAS and SDAS decrease when the withdrawal rate is increased. Compared with the theoretical models of PDAS, the results are in good agreement with Trivedi’s model. The relationships of PDAS and SDAS with withdrawal rates can be described as l1 = 649.7V -0.24±0.02 and l2 = 281V -0.32±0.03, respectively. In addition, the size of the γ′ phase significantly decreases with increasing withdrawal rate.

  18. Crystallization and preliminary crystallographic analysis of GanB, a GH42 intracellular β-galactosidase from Geobacillus stearothermophilus.

    Science.gov (United States)

    Solomon, Hodaya V; Tabachnikov, Orly; Feinberg, Hadar; Govada, Lata; Chayen, Naomi E; Shoham, Yuval; Shoham, Gil

    2013-10-01

    Geobacillus stearothermophilus T-6 is a Gram-positive thermophilic soil bacterium that contains a multi-enzyme system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. The bacterium uses a number of endo-acting extracellular enzymes that break down the high-molecular-weight polysaccharides into decorated oligosaccharides. These oligosaccharides enter the cell and are further hydrolyzed into sugar monomers by a set of intracellular glycoside hydrolases. One of these intracellular degrading enzymes is GanB, a glycoside hydrolase family 42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides to galactose. GanB and related enzymes therefore play an important part in the hemicellulolytic utilization system of many microorganisms which use plant biomass for growth. The interest in the biochemical characterization and structural analysis of these enzymes stems from their potential biotechnological applications. GanB from G. stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized in our laboratory as part of its complete structure-function study. The best crystals obtained for this enzyme belong to the primitive orthorhombic space group P2₁2₁2₁, with average crystallographic unit-cell parameters of a=71.84, b=181.35, c=196.57 Å. Full diffraction data sets to 2.45 and 2.50 Å resolution have been collected for both the wild-type enzyme and its E323A nucleophile catalytic mutant, respectively, as measured from flash-cooled crystals at 100 K using synchrotron radiation. These data are currently being used for the full three-dimensional crystal structure determination of GanB.

  19. Analysis of Fractal Parameters of the Lunar Surface

    Science.gov (United States)

    Nefedyev, Yuri; Petrova, Natalia; Andreev, Alexey; Demina, Natalya; Demin, Sergey

    2016-07-01

    Analysis of complex selenographic systems is a complicatedissue. This fully applies to the lunar topography. In this report a new method of the comparative reliable estimation of thelunar mapsdata is represented. The estimation was made by the comparison of high-altitude lines using the fractal analysis. The influence of the lunar macrofigure variances were determined by the method of fractal dimensions comparison. It should be noted the investigations of the lunar figure and rotation implystudy itsmarginal zone charts constructionwith various methods and this is traditionally carried out at the Engelhardt Astronomical Observatory (EAO). In particular this research is important for lunar occultations reductions and on the basis of that it is possible to solve a number of astrometric and astrophysical problems. By now the highly accurate theories of the lunar movement have been obtained and stars coordinates have been determined on the basis of space measurements with the several multiarcseconds accuracy but there are factors highly influencingon the accuracy of the results of these observations. They are: exactitude of the occultation moment recording, errors of the stars coordinates, accuracy of lunar ephemeris positions and unreliability of lunar marginal zone charts. Therefore difficulties arise during the reduction process of lunar occultations by the reason of irregularities of lunar limb. Existing charts of the lunar marginal zone have some defects. The researching of lunar marginal zone maps is very difficult. First of all, it concernsthe reliability of maps data. To resolve this task thecomparison method in which the structure of the high-altitude lines of data appropriated with identical lunar coordinates can used. However, such comparison requires a lot of calculations. In addition there is a large number of the marginal zone maps constructed by different methods and the accuracy of their data causes many questions. In other words, the lunar relief has a

  20. Crystallization and preliminary crystallographic analysis of l-asparaginase from Erwinia carotovora

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, Linnea E. K. [Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20521 (Finland); Krasotkina, Julya; Kuchumova, Anastasia; Sokolov, Nikolay N. [Institute for Biomedical Chemistry, Russian Academy of Medical Sciences, 559-B, 10 Pogodinskay St, Moscow 119121 (Russian Federation); Papageorgiou, Anastassios C., E-mail: tassos.papageorgiou@btk.fi [Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku 20521 (Finland)

    2005-04-01

    Er. carotovoral-asparaginase, a potential antileukaemic agent, has been crystallized. Crystals diffract to 2.6 Å using a rotating-anode source and belong to space group P2{sub 1}, with unit-cell parameters a = 78.0, b = 112.3, c = 78.7 Å, β = 101.9° and a homotetramer in the crystallographic asymmetric unit. Bacterial l-asparaginases have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia for over 30 y. However, their use is limited owing to the glutaminase activity of the administered enzymes, which results in serious side effects. In contrast, l-asparaginase from Erwinia carotovora exhibits low glutaminase activity at physiological concentrations of l-asparagine and l-glutamine in the blood. Recombinant Er. carotovoral-asparaginase was crystallized in the presence of l-glutamate by the hanging-drop vapour-diffusion method using 10 mg ml{sup −1} purified enzyme, 16–18%(w/v) PEG 3350 and 0.2 M NaF. X-ray diffraction data were collected to 2.6 Å at 293 K using an in-house rotating-anode generator. The crystals belong to the monoclinic P2{sub 1} space group, with unit-cell parameters a = 78.0, b = 112.3, c = 78.7 Å, β = 101.9° and a homotetramer in the crystallographic asymmetric unit. A molecular-replacement solution has been found and refinement is currently in progress. The crystal structure may provide leads towards protein-engineering efforts aimed at safer asparaginase administration in leukaemia treatment.

  1. Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

    Science.gov (United States)

    Xiao, Shou-Ne; Wang, Ming-Meng; Hu, Guang-Zhong; Yang, Guang-Wu

    2017-09-01

    In view of the problem that it's difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out-in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary conditions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the application of forward design method to high-speed trains.

  2. Kinematic Seismic Rupture Parameters from a Doppler Analysis

    Science.gov (United States)

    Caldeira, Bento; Bezzeghoud, Mourad; Borges, José F.

    2010-05-01

    The radiation emitted from extended seismic sources, mainly when the rupture spreads in preferred directions, presents spectral deviations as a function of the observation location. This aspect, unobserved to point sources, and named as directivity, are manifested by an increase in the frequency and amplitude of seismic waves when the rupture occurs in the direction of the seismic station and a decrease in the frequency and amplitude if it occurs in the opposite direction. The model of directivity that supports the method is a Doppler analysis based on a kinematic source model of rupture and wave propagation through a structural medium with spherical symmetry [1]. A unilateral rupture can be viewed as a sequence of shocks produced along certain paths on the fault. According this model, the seismic record at any point on the Earth's surface contains a signature of the rupture process that originated the recorded waveform. Calculating the rupture direction and velocity by a general Doppler equation, - the goal of this work - using a dataset of common time-delays read from waveforms recorded at different distances around the epicenter, requires the normalization of measures to a standard value of slowness. This normalization involves a non-linear inversion that we solve numerically using an iterative least-squares approach. The evaluation of the performance of this technique was done through a set of synthetic and real applications. We present the application of the method at four real case studies, the following earthquakes: Arequipa, Peru (Mw = 8.4, June 23, 2001); Denali, AK, USA (Mw = 7.8; November 3, 2002); Zemmouri-Boumerdes, Algeria (Mw = 6.8, May 21, 2003); and Sumatra, Indonesia (Mw = 9.3, December 26, 2004). The results obtained from the dataset of the four earthquakes agreed, in general, with the values presented by other authors using different methods and data. [1] Caldeira B., Bezzeghoud M, Borges JF, 2009; DIRDOP: a directivity approach to determining

  3. Changes in microstructural parameters of NB4D2 silk fibres due to electron irradiation: X-ray line profile analysis

    Indian Academy of Sciences (India)

    Sangappa; S Asha; P Parameswara; R Somashekar

    2011-12-01

    The present study is concerned with changes of microcrystalline parameters in NB4D2 (Bombyx mori) silk fibres, due to electron irradiation. The irradiation process was performed in air at room temperature using 8 MeV electron beam at different dose rates: 0, 25, 50 and 75 kGy, respectively. X-ray recording of these irradiated samples and the line profile analysis were carried out. The crystal imperfection parameters such as crystallite size $\\langle N \\rangle$, lattice strain (g in %) and surface weighted crystallite size ($D_{s}$) were computed and compared with other physical parameters in order to asertain the changes that have crept into these irradiated fibres. Exponential, lognormal and Reinhold functions for the column length distributions have been used for the determination of these parameters.

  4. Molecular Weight and Crystallization Temperature Effects on Poly(ethylene terephthalate (PET Homopolymers, an Isothermal Crystallization Analysis

    Directory of Open Access Journals (Sweden)

    Leonardo A. Baldenegro-Perez

    2014-02-01

    Full Text Available The isothermal crystallization of poly(ethylene terephthalate (PET homopolymers with different molecular weight was studied in a wide temperature range (140–230 °C using different experimental techniques. Three different morphological regions, labeled r1, r2 and r3, were distinguished as a function of crystallization temperature (Tc. In r1 (low Tc crystallized samples were characterized by a low crystalline degree with a small spherulite texture containing thin crystals. In r2 (intermediate Tc samples showed medium size spherulites composed of two distinct crystalline families (thin and thick crystals. In this temperature range, the crystallization exhibited a maximum value and it was associated with a high content of secondary crystals. In r3 (high Tc, samples presented considerable amorphous zones and regions consisting of oversized spherulites containing only thick crystals. Time-resolved wide-angle X-ray diffraction measurements, using synchrotron radiation, indicated a rapid evolution of the crystalline degree within the second region, in contrast with the quite slow evolution observed in the third region. On the other hand, by small-angle X-ray scattering (SAXS and time-resolved SAXS experiment, it was found that the long period (L as well as the lamellar thickness (lc increase as a function of Tc, corroborating the formation of the thickest crystals in the third region. From all these observations, a morphological model was proposed for each region.

  5. Parameter subset selection for the dynamic calibration of activated sludge models (ASMs): experience versus systems analysis

    DEFF Research Database (Denmark)

    Ruano, MV; Ribes, J; de Pauw, DJW

    2007-01-01

    In this work we address the issue of parameter subset selection within the scope of activated sludge model calibration. To this end, we evaluate two approaches: (i) systems analysis and (ii) experience-based approach. The evaluation has been carried out using a dynamic model (ASM2d) calibrated...... based approaches which excluded them from their analysis. Systems analysis reveals that parameter significance ranking and size of the identifiable parameter subset depend on the information content of data available for calibration. However, it suffers from heavy computational demand. In contrast...

  6. The Influence of Technological PVD Process Parameters on the Topography, Crystal and Molecular Structure of Nanocomposite Films Containing Palladium Nanograins

    Directory of Open Access Journals (Sweden)

    Rymarczyk Joanna

    2014-09-01

    Full Text Available The paper describes the preparation and characteristics of films composed of Pd nanograins placed in carbonaceous matrix. Films were obtained in PVD (Physical Vapor Deposition process from two sources containing: the first one - fullerene powder and the second one - palladium acetate. The topographical, morphological and structural changes due to different parameters of PVD process were studied with the use of Atomic Force Microscopy and Scanning Electron Microscopy, whereas the structure was studied with the application of the Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy methods. It was shown that topographical changes are connected with the decomposition ratio of Pd acetate as well as the form of carbonaceous matrix formed due to this decomposition. Palladium nanograins found in all films exhibit the fcc structure type and their diameter changes from 2 nm to 40 nm depending on the PVD process parameters.

  7. Crystal structure and order parameters in the phase transition of antiferroelectric PbZrO sub 3

    CERN Document Server

    Fujishita, H; Tanaka, S; Ogawaguchi, A; Katano, S

    2003-01-01

    X-ray and neutron diffraction and dielectric measurements were performed for the antiferroelectric phase of PbZrO sub 3. The antiferroelectric SIGMA sub 3 (TO) and the R sub 2 sub 5 superlattice-reflection intensities, and the pseudo-tetragonal lattice distortion of the perovskite sublattice showed the same temperature dependence below room temperature, showing a saturation below about 60 K. Above room temperature, however, they showed rather different temperature dependences. These temperature dependences can be well described by the free energy based on a group theoretical method, which includes a quantum effect. The atomic shifts do not necessarily conform to a simple concept of order parameter in soft mode condensation. However the antiferroelectric phase transition can be understood by the phenomenological theory for coupled order parameters if applied over the whole temperature region. (author)

  8. Modeling and Sensitivity Analysis of Navigation Parameter Errors for Airborne Synthetic Aperture Radar Stereo Geolocation

    Institute of Scientific and Technical Information of China (English)

    PANG Lei; ZHANG Jixian; YAN Qin

    2010-01-01

    For the high-resolution airborne synthetic aperture radar (SAR) stereo geolocation application, the final geolocation accuracy is influenced by various error parameter sources. In this paper, an airborne SAR stereo geolocation parameter error model,involving the parameter errors derived from the navigation system on the flight platform, has been put forward. Moreover, a kind of near-direct method for modeling and sensitivity analysis of navigation parameter errors is also given. This method directly uses the ground reference to calculate the covariance matrix relationship between the parameter errors and the eventual geolocation errors for ground target points. In addition, utilizing true flight track parameters' errors, this paper gave a verification of the method and a corresponding sensitivity analysis for airborne SAR stereo geolocation model and proved its efficiency.

  9. Optimization of process parameters in drilling of fibre hybrid composite using Taguchi and grey relational analysis

    Science.gov (United States)

    Vijaya Ramnath, B.; Sharavanan, S.; Jeykrishnan, J.

    2017-03-01

    Nowadays quality plays a vital role in all the products. Hence, the development in manufacturing process focuses on the fabrication of composite with high dimensional accuracy and also incurring low manufacturing cost. In this work, an investigation on machining parameters has been performed on jute-flax hybrid composite. Here, the two important responses characteristics like surface roughness and material removal rate are optimized by employing 3 machining input parameters. The input variables considered are drill bit diameter, spindle speed and feed rate. Machining is done on CNC vertical drilling machine at different levels of drilling parameters. Taguchi’s L16 orthogonal array is used for optimizing individual tool parameters. Analysis Of Variance is used to find the significance of individual parameters. The simultaneous optimization of the process parameters is done by grey relational analysis. The results of this investigation shows that, spindle speed and drill bit diameter have most effect on material removal rate and surface roughness followed by feed rate.

  10. Guidance in Kagome-like photonic crystal fibres I: analysis of an ideal fibre structure.

    Science.gov (United States)

    Chen, Lei; Pearce, Greg J; Birks, Timothy A; Bird, David M

    2011-03-28

    Propagation of light in a square-lattice hollow-core photonic crystal fibre is analysed as a model of guidance in a class of photonic crystal fibres that exhibit broad-band guidance without photonic bandgaps. A scalar governing equation is used and analytic solutions based on transfer matrices are developed for the full set of modes. It is found that an exponentially localised fundamental mode exists for a wide range of frequencies. These analytic solutions of an idealised structure will form the basis for analysis of guidance in a realistic structure in a following paper.

  11. Expression, purification, crystallization and preliminary crystallographic analysis of human Pim-1 kinase

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Kevin C., E-mail: kqian@rdg.boehringer-ingelheim.com [Department of Medicinal Chemistry, Boehringer Ingelheim Pharmaceuticals Inc., Research and Development, 175 Briar Ridge Road, Ridgefield, CT 06877 (United States); Studts, Joey; Wang, Lian; Barringer, Kevin; Kronkaitis, Anthony; Peng, Charline; Baptiste, Alistair; LaFrance, Roger; Mische, Sheenah [Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals Inc., Research and Development, 175 Briar Ridge Road, Ridgefield, CT 06877 (United States); Farmer, Bennett [Department of Medicinal Chemistry, Boehringer Ingelheim Pharmaceuticals Inc., Research and Development, 175 Briar Ridge Road, Ridgefield, CT 06877 (United States)

    2005-01-01

    Pim kinases, belong to a distinctive serine/threonine protein-kinase family and are involved in cytokine-induced signal transduction and the development of lymphoid malignancies. Human Pim-1 kinase has been cloned, expressed and crystallized Pim kinases, including Pim-1, Pim-2 and Pim-3, belong to a distinctive serine/threonine protein-kinase family. They are involved in cytokine-induced signal transduction and the development of lymphoid malignancies. Their kinase domains are highly homologous to one another, but share low sequence identity to other kinases. Specifically, there are two proline residues in the conserved hinge-region sequence ERPXPX separated by a residue that is non-conserved among Pim kinases. Full-length human Pim-1 kinase (1–313) was cloned and expressed in Escherichia coli as a GST-fusion protein and truncated to Pim-1 (14–313) by thrombin digestion during purification. The Pim-1 (14–313) protein was purified to high homogeneity and monodispersity. This protein preparation yielded small crystals in the initial screening and large crystals after optimization. The large crystals of apo Pim-1 enzyme diffracted to 2.1 Å resolution and belong to space group P6{sub 5}, with unit-cell parameters a = b = 95.9, c = 80.0 Å, β = 120° and one molecule per asymmetric unit.

  12. Crystallization and preliminary crystallographic analysis of d-alanine-d-alanine ligase from Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yong-Zhi; Sheng, Yu [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Li, Lan-Fen [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Tang, De-Wei [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liu, Xiang-Yu [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Zhao, Xiaojun, E-mail: zhaoxj@scu.edu.cn [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liang, Yu-He, E-mail: zhaoxj@scu.edu.cn; Su, Xiao-Dong [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China)

    2007-09-01

    A potential target for antibiotic drug design, d-alanine-d-alanine ligase from S. mutans, was expressed in E. coli, purified and crystallized. Diffraction data were collected to 2.4 Å resolution. d-Alanine-d-alanine ligase is encoded by the gene ddl (SMU-599) in Streptococcus mutans. This ligase plays a very important role in cell-wall biosynthesis and may be a potential target for drug design. To study the structure and function of this ligase, the gene ddl was amplified from S. mutans genomic DNA and cloned into the expression vector pET28a. The protein was expressed in soluble form in Escherichia coli strain BL21 (DE3). Homogeneous protein was obtained using a two-step procedure consisting of Ni{sup 2+}-chelating and size-exclusion chromatography. Purified protein was crystallized and the cube-shaped crystal diffracted to 2.4 Å. The crystal belongs to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 79.50, c = 108.97 Å. There is one molecule per asymmetric unit.

  13. Expression purification crystallization and preliminary X-ray analysis of Pseudomonas aeruginosa PelD

    Energy Technology Data Exchange (ETDEWEB)

    Marmont L. S.; Robinson H.; Whitney J. C.; Colvin K. M.; Parsek M. R.; Howell P. L.

    2012-02-01

    The production of the PEL polysaccharide in Pseudomonas aeruginosa requires the binding of bis-(3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP) to the cytoplasmic GGDEF domain of the inner membrane protein PelD. Here, the overexpression, purification and crystallization of a soluble construct of PelD that encompasses the GGDEF domain and a predicted GAF domain is reported. Diffraction-quality crystals were grown using the hanging-drop vapour-diffusion method. The crystals grew as flat plates, with unit-cell parameters a = 88.3, b = 114.0, c = 61.9 {angstrom}, {alpha} = {beta} = {gamma} = 90.0{sup o}. The PelD crystals exhibited the symmetry of space group P2{sub 1}2{sub 1}2 and diffracted to a minimum d-spacing of 2.2 {angstrom}. On the basis of the Matthews coefficient (V{sub M} = 2.29 {angstrom}{sup 3} Da{sup -1}), it was estimated that two molecules are present in the asymmetric unit.

  14. Overexpression, crystallization and preliminary X-ray crystallographic analysis of phosphopantetheine adenylyltransferase from Enterococcus faecalis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ji Yong; Lee, Hyung Ho; Yoon, Hye Jin; Kim, Hyoun Sook; Suh, Se Won, E-mail: sewonsuh@snu.ac.kr [Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2006-11-01

    Phosphopantetheine adenylyltransferase from En. faecalis was crystallized and X-ray diffraction data were collected to 2.70 Å resolution. Phosphopantetheine adenylyltransferase, an essential enzyme in the coenzyme A biosynthetic pathway, catalyzes the reversible transfer of an adenylyl group from ATP to 4′-phosphopantetheine, yielding 3′-dephospho-CoA and pyrophosphate. Enterococcus faecalis PPAT has been overexpressed in Escherichia coli as a fusion with a C-terminal purification tag and crystallized at 297 K using a reservoir solution consisting of 0.1 M sodium HEPES pH 7.5, 0.8 M sodium dihydrogen phosphate and 0.8 M potassium dihydrogen phosphate. X-ray diffraction data were collected to 2.70 Å at 100 K. The crystals belong to the primitive tetragonal space group P4{sub 1} (or P4{sub 3}), with unit-cell parameters a = b = 160.81, c = 225.68 Å. Four copies of the hexameric molecule are likely to be present in the asymmetric unit, giving a crystal volume per protein weight (V{sub M}) of 3.08 Å{sup 3} Da{sup −1} and a solvent content of 60.1%.

  15. Crystallization and preliminary crystallographic analysis of poly(3-hydroxybutyrate) depolymerase from Bacillus thuringiensis

    Science.gov (United States)

    Wang, Yung-Lin; Lin, Yi-Ting; Chen, Chia-Lin; Shaw, Gwo-Chyuan; Liaw, Shwu-Huey

    2014-01-01

    Poly[(R)-3-hydroxybutyrate] (PHB) is a microbial biopolymer that has been commercialized as biodegradable plastics. The key enzyme for the degradation is PHB depolymerase (PhaZ). A new intracellular PhaZ from Bacillus thuringiensis (BtPhaZ) has been screened for potential applications in polymer biodegradation. Recombinant BtPhaZ was crystallized using 25% polyethylene glycol 3350, 0.2 M ammonium acetate, 0.1 M bis-tris pH 6.5 at 288 K. The crystals belonged to space group P1, with unit-cell parameters a = 42.97, b = 83.23, c = 85.50 Å, α = 73.45, β = 82.83, γ = 83.49°. An X-ray diffraction data set was collected to 1.42 Å resolution with an R merge of 6.4%. Unexpectedly, a molecular-replacement solution was obtained using the crystal structure of Streptomyces lividans chloroperoxidase as a template, which shares 24% sequence identity to BtPhaZ. This is the first crystal structure of an intracellular poly(3-hydroxybutyrate) depolymerase. PMID:25286954

  16. Crystallization and preliminary diffraction analysis of a DsbA homologue from Wolbachia pipientis

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, M. [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia); Iturbe-Ormaetxe, I. [School of Integrative Biology, The University of Queensland, St Lucia, QLD 4072 (Australia); Jarrott, R. [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia); O’Neill, S. L. [School of Integrative Biology, The University of Queensland, St Lucia, QLD 4072 (Australia); Byriel, K. A.; Martin, J. L., E-mail: j.martin@imb.uq.edu.au; Heras, B., E-mail: j.martin@imb.uq.edu.au [Institute for Molecular Bioscience and ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, St Lucia, QLD 4072 (Australia)

    2008-02-01

    The first crystallization of a W. pipientis protein, α-DsbA1, was achieved using hanging-drop and sitting-drop vapour diffusion. α-DsbA1 is one of two DsbA homologues encoded by the Gram-negative α-proteobacterium Wolbachia pipientis, an endosymbiont that can behave as a reproductive parasite in insects and as a mutualist in medically important filarial nematodes. The α-DsbA1 protein is thought to be important for the folding and secretion of Wolbachia proteins involved in the induction of reproductive distortions. Crystals of native and SeMet α-DsbA1 were grown by vapour diffusion and belong to the monoclinic space group C2, with unit-cell parameters a = 71.4, b = 49.5, c = 69.3 Å, β = 107.0° and one molecule in the asymmetric unit (44% solvent content). X-ray data were recorded from native crystals to a resolution of 2.01 Å using a copper anode and data from SeMet α-DsbA1 crystals were recorded to 2.45 Å resolution using a chromium anode.

  17. Analysis of guided-resonance-based polarization beam splitting in photonic crystal slabs.

    Science.gov (United States)

    Kilic, Onur; Fan, Shanhui; Solgaard, Olav

    2008-11-01

    We present an analysis of the phase and amplitude responses of guided resonances in a photonic crystal slab. Through this analysis, we obtain the general rules and conditions under which a photonic crystal slab can be employed as a general elliptical polarization beam splitter, separating an incoming beam equally into its two orthogonal constituents, so that half the power is reflected in one polarization state, and half the power is transmitted in the other state. We show that at normal incidence a photonic crystal slab acts as a dual quarter-wave retarder in which the fast and slow axes are switched for reflection and transmission. We also analyze the case where such a structure operates at oblique incidences. As a result we show that the effective dielectric constant of the photonic crystal slab imposes the Brewster angle as a boundary, separating two ranges of angles with different mechanisms of polarization beam splitting. We show that the diattenuation can be tuned from zero to one to make the structure a circular or linear polarization beam splitter. We verify our analytical analysis through finite-difference time-domain simulations and experimental measurements at infrared wavelengths.

  18. Iso-conversional kinetic analysis of quaternary glass re-crystallization.

    Science.gov (United States)

    Srivastava, Ankita; Chandel, Namrata; Mehta, Neeraj

    2017-02-01

    Iso-conversional kinetic analysis is popular in scientific community for analyzing solid-state reactions (e.g., glass/amorphous and amorphous/crystal phase transformations, re-crystallization etc). It is a recognized significant tool to achieve useful outcomes for the solid state reaction under consideration. Present work is devoted to explore some insights of thermally activated crystallization using various heating rates (VHR) method. We have examined the correlation between iso-conversional activation energy and iso-conversional rate of crystal growth. In fact, we have observed the compensation law and iso-kinetic relationship using two different approaches for the study of crystallization phenomenon that drives thermally in an Arrhenian manner. Moreover, we found that the estimated intercepts and gradients (i.e., Meyer-Neldel energy and Meyer-Neldel pre-factor respectively) for both approaches also vary linearly and both sets are remarkably identical. These results approach to an inference for ensuring the equivalence of compensation law and iso-kinetic relationship and provide an understanding of various advanced materials in physical chemistry, materials sciences and solid-state physics.

  19. Analysis of Al-Mg casting alloys crystallization with use of „ATND” method

    Directory of Open Access Journals (Sweden)

    T. Ciućka

    2008-12-01

    Full Text Available The paper presents results of non-ferrous metals crystallization tests performed with use of the ATND method. Such tests are performed in the Institute of Chipless Technology, Academy of Technology and Humanities in Bielsko-Biala. Method of analysis of non-ferrous metals crystallization gives complete picture of arisen structural components of alloys. Particular structural components of alloys investigated with use of the ATND method were verified in x-ray microanalysis, what unequivocally confirmed their presence. Below are presented in graphical form (crystallization diagrams results of crystallization process obtained from the ATND method. In crystallization diagrams of AlMg10 and AG51 alloys are shown curves (thermal curve and its derivative, voltage curve and its derivative. Crystallizable individual structural components of the investigated alloys are reflected on curves of the method in form of characteristic peaks. The tests were performed with AlMg10 and AlMg5Si1 aluminum-magnesium alloys casting. Moreover, the paper presents structures of the investigated alloys with marked structural components identified with use of x-ray microanalysis.

  20. Ultrasonic motion analysis system - measurement of temporal and spatial gait parameters

    NARCIS (Netherlands)

    Huitema, RB; Hof, AL; Postema, K

    2002-01-01

    The duration of stance and swing phase and step and stride length are important parameters in human gait. In this technical note a low-cost ultrasonic motion analysis system is described that is capable of measuring these temporal and spatial parameters while subjects walk on the floor. By using the

  1. Effect of crystal habit on the dissolution behaviour of simvastatin crystals and its relationship to crystallization solvent properties.

    Science.gov (United States)

    Bukovec, P; Benkic, P; Smrkolj, M; Vrecer, F

    2016-05-01

    Simvastatin crystals, having same crystal structure but different types of habits and hence different intrinsic dissolution rate, were prepared by recrystallization from solvents selected according to their polarity index. Scanning electron microscopy, laser diffraction, image analysis, X-ray powder diffractometry, Fourier transform infrared spectroscopy and differential scanning calorimetry were used to investigate the physicochemical characteristics of the prepared crystals. The isolated crystals exhibited different crystal habits but possessed the same internal crystal structure. In this study the comparative intrinsic dissolution behaviour of the simvastatin crystals with different types of habits was studied and explained by surface energy and correlated to different solvent systems that were used for crystallization. In our work we diminished the influence of all other physical parameters that could influence the dissolution rate, e.g. particle size, specific surface area and polymorphism in order to focus the study onto the impact of crystal shape itself on the dissolution rate of simvastatin crystals. Rod shaped crystals isolated from more hydrophilic solvent mixture dissolved faster than plate-like crystals obtained from solvent mixture with lower polarity index. We correlated this fact to the different growth rate of the individual faces which resulted in different relative size of the individual crystal faces exposed to the dissolution medium as well as the chemical nature of those faces which in turn influenced the wettability and subsequent dissolution of the active pharmaceutical ingredient.

  2. Archaeal acylamino acid releasing enzyme/lipase: Crystallization and preliminary crystallographic analysis in a new crystal form

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A primitive orthorhombic crystal form of acylamino acid releasing enzyme/lipase (APE1547) from hyperthermophilic archaeon Aeropyrum pernix strain K1 has been obtained at 291 K. The diffraction pattern of the crystal extends to 0.27 nm resolution at 100 K using Cu Kαradiation. The crystal belongs to the space group P212121 with unit cell dimensions of a = 6.399, b = 10.439 and c = 16.953 nm. The presence of two molecules per asymmetric unit gives a crystal volume per protein mass (Vm) of 0.0022 nm3 Da-1 and a solvent content of 43% by volume. A full set of X-ray diffraction data were collected to 0.3 nm from the native crystal.

  3. The Effects of Annealing Parameters on the Crystallization and Morphology of Cu(In,GaSe2 Absorber Layers Prepared by Annealing Stacked Metallic Precursors

    Directory of Open Access Journals (Sweden)

    Chia-Ho Huang

    2014-01-01

    Full Text Available CIGS films are prepared by single-stage annealing of the solid Se-coated In/Cu-Ga bilayer precursor. The annealing processes were performed using various Ar pressures, heating rates, and soaking times. A higher Ar pressure is needed to fabricate highly crystalline CIGS films, as no extra Se-vapor source is supplied. As the heating rate increases, the surface morphologies of the CIGS films become looser and some cracks are observed. However, the influence of soaking time is insignificant and the selenization process only requires a short time when the precursors are selenized at a higher temperature with a lower heating rate and a higher Ar pressure. In this study, a dense chalcopyrite CIGS film with a thickness of about 1.5-1.6 μm, with large grains (~1.2 μm and no cracking or peeling is obtained after selenizing at a temperature of 550°C, an Ar pressure of 300 Torr, a heating rate of 60°C/min, and a soaking time of 20 min. By adequate design of the stacked precursor and controlling the annealing parameters, single-stage annealing of the solid Se-coated In/Cu-Ga bilayer precursor is simplified for the fabrication of a fully crystallized chalcopyrite CIGS absorber layers with good crystallization and large grains.

  4. Fukushima Daiichi unit 1 uncertainty analysis--Preliminary selection of uncertain parameters and analysis methodology

    Energy Technology Data Exchange (ETDEWEB)

    Cardoni, Jeffrey N.; Kalinich, Donald A.

    2014-02-01

    Sandia National Laboratories (SNL) plans to conduct uncertainty analyses (UA) on the Fukushima Daiichi unit (1F1) plant with the MELCOR code. The model to be used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). However, that study only examined a handful of various model inputs and boundary conditions, and the predictions yielded only fair agreement with plant data and current release estimates. The goal of this uncertainty study is to perform a focused evaluation of uncertainty in core melt progression behavior and its effect on key figures-of-merit (e.g., hydrogen production, vessel lower head failure, etc.). In preparation for the SNL Fukushima UA work, a scoping study has been completed to identify important core melt progression parameters for the uncertainty analysis. The study also lays out a preliminary UA methodology.

  5. A Multi-parameter Data Acquisition and Analysis System Based on Open VMS Operation System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We fall into disuse the JUHU system based on the PDP/11 computer for RSX11M operation system,and update our multi-parameter data aequisition and analysis system’s hardware and software based on VAXII computer and Open VMS operation system,make it adapted to the recent physics experiment.In this paper,we describe the updated inulti-parameter data acquisition and analysis system’s hardware,software configuration and system function.

  6. Crystallization and preliminary X-ray diffraction analysis of two extracytoplasmic solute receptors of the DctP family from Bordetella pertussis

    Energy Technology Data Exchange (ETDEWEB)

    Rucktooa, Prakash; Huvent, Isabelle [UMR8161 CNRS Institut de Biologie de Lille, Laboratoire de Cristallographie Macromoléculaire, 1 Rue du Professeur Calmette, BP 447, 59021 Lille CEDEX (France); IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); Antoine, Rudy; Lecher, Sophie; Jacob-Dubuisson, Françoise, E-mail: francoise.jacob@ibl.fr [IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); INSERM-U629, Lille (France); Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); Villeret, Vincent, E-mail: francoise.jacob@ibl.fr; Bompard, Coralie [UMR8161 CNRS Institut de Biologie de Lille, Laboratoire de Cristallographie Macromoléculaire, 1 Rue du Professeur Calmette, BP 447, 59021 Lille CEDEX (France); IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France)

    2006-10-01

    Sample preparation, crystallization and preliminary X-ray analysis are reported for two B. pertussis extracytoplasmic solute receptors. DctP6 and DctP7 are two Bordetella pertussis proteins which belong to the extracytoplasmic solute receptors (ESR) superfamily. ESRs are involved in the transport of substrates from the periplasm to the cytosol of Gram-negative bacteria. DctP6 and DctP7 have been crystallized and diffraction data were collected using a synchrotron-radiation source. DctP6 crystallized in space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 108.39, b = 108.39, c = 63.09 Å, while selenomethionyl-derivatized DctP7 crystallized in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 64.87, b = 149.83, c = 170.65 Å. The three-dimensional structure of DctP7 will be determined by single-wavelength anomalous diffraction, while the DctP6 structure will be solved by molecular-replacement methods.

  7. Spray-deposited CuIn{sub 1-x}Ga{sub x}Se{sub 2} solar cell absorbers: Influence of spray deposition parameters and crystallization promoters

    Energy Technology Data Exchange (ETDEWEB)

    Carrete, Alex; Placidi, Marcel; Shavel, Alexey [Catalonia Institute for Energy Research - IREC, Sant Adria del Besos, Barcelona (Spain); Perez-Rodriguez, Alejandro [Catalonia Institute for Energy Research - IREC, Sant Adria del Besos, Barcelona (Spain); IN2UB, Departament d' Electronica, Universitat de Barcelona (Spain); Cabot, Andreu [Catalonia Institute for Energy Research - IREC, Sant Adria del Besos, Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats - ICREA, Barcelona (Spain)

    2015-01-01

    To produce smooth, crack-free, and highly crystalline absorber layers are the main challenges in the fabrication of thin film solar cells using nanoparticle-based solution-processing technologies. In this work, we report on the optimization of the spray deposition parameters to produce highly homogeneous CuIn{sub 1-x}Ga{sub x}S{sub 2} thin films with controlled thickness using nanoparticle-based inks. We further explore the use of inorganic ligand exchange strategies to introduce metal ions able to promote crystallization during the selenization of the layers, removing structural defects and grain boundaries that potentially act as recombination centers. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Impact parameter dependent electron capture by decelerated U{sup 91+} ions at 20 MeV/u using crystal channeling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dauvergne, D. E-mail: d.dauvergne@ipnl.in2p3.fr; Braeuning-Demian, A.; Bosch, F.; Braeuning, H.; Chevallier, M.; Cohen, C.; Gumberidze, A.; L' Hoir, A.; Kirsch, R.; Kozhuharov, C.; Liesen, D.; Mokler, P.H.; Poizat, J.C.; Ray, C.; Stoehlker, Th.; Tarisien, M.; Testa, E.; Toleikis, S.; Toulemonde, M

    2003-05-01

    We present results of an experiment using decelerated U{sup 91+} ions, extracted from the GSI-ESR storage ring, and transmitted through a thin silicon crystal in channeling conditions. Charge state at emergence, secondary electron multiplicity and X-rays are measured simultaneously. These conditions allow to study the competition between mechanical electron capture (MEC) and radiative electron capture (REC) as a function of impact parameter. We observe that REC is the dominant charge exchange process for the best channeled ions, i.e. those travelling always far from the silicon target core electrons. For ions with high transverse energy, MEC into highly excited states is counterbalanced by enhanced ionization arising from a succession of close collisions along atomic rows.

  9. Crystallization and preliminary crystallographic analysis of beta-L-arabinopyranosidase from Streptomyces avermitilis NBRC14893.

    Science.gov (United States)

    Fujimoto, Zui; Ichinose, Hitomi; Harazono, Koichi; Honda, Mariko; Uzura, Atsuko; Kaneko, Satoshi

    2009-06-01

    Beta-L-arabinopyranosidase from Streptomyces avermitilis NBRC14893 is a monomeric protein consisting of a catalytic domain belonging to glycosyl hydrolase family 27, an unknown domain and a substrate-binding domain belonging to carbohydrate-binding module family 13. The complete enzyme (residues 45-658) has successfully been cloned and homologously expressed in the Streptomyces expression system. beta-L-Arabinopyranosidase was crystallized by the sitting-drop vapour-diffusion method. The crystals diffracted to 1.6 A resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 68.2, b = 98.9, c = 181.3 A. The Matthews coefficient was calculated to be 2.38 A(3) Da(-1).

  10. Expression, crystallization and preliminary X-ray crystallographic analysis of alcohol dehydrogenase (ADH) from Kangiella koreensis.

    Science.gov (United States)

    Ngo, Ho-Phuong-Thuy; Hong, Seung-Hye; Hong, Myoung-Ki; Pham, Tan-Viet; Oh, Deok-Kun; Kang, Lin-Woo

    2013-09-01

    Alcohol dehydrogenases (ADHs) are a group of dehydrogenase enzymes that facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of NAD(+) to NADH. In bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD(+). The adh gene from Kangiella koreensis was cloned and the protein (KkADH) was expressed, purified and crystallized. A KkADH crystal diffracted to 2.5 Å resolution and belonged to the monoclinic space group P2(1), with unit-cell parameters a = 94.1, b = 80.9, c = 115.6 Å, β = 111.9°. Four monomers were present in the asymmetric unit, with a corresponding VM of 2.55 Å(3) Da(-1) and a solvent content of 51.8%.

  11. Expression, purification, crystallization and preliminary X-ray crystallographic analysis of Zucchini from Drosophila melanogaster.

    Science.gov (United States)

    Fukuhara, Satoshi; Nishimasu, Hiroshi; Bonnefond, Luc; Matsumoto, Naoki; Ishitani, Ryuichiro; Nureki, Osamu

    2012-11-01

    PIWI-interacting RNAs (piRNAs) bind PIWI proteins and silence transposons to maintain the genomic integrity of germ cells. Zucchini (Zuc), a phospholipase D superfamily member, is conserved among animals and is implicated in piRNA biogenesis. However, the underlying mechanism by which Zuc participates in piRNA biogenesis remains elusive. Drosophila melanogaster Zuc (DmZuc) was expressed in Escherichia coli, purified and crystallized. X-ray diffraction data were collected to 1.75 Å resolution. The crystal belonged to space group P2(1), with unit-cell parameters a=55.0, b=71.2, c=56.3 Å, β=107.9°.

  12. Thermal analysis of the vertical bridgman semiconductor crystal growth technique. Ph.D. Thesis

    Science.gov (United States)

    Jasinski, T. J.

    1982-01-01

    The quality of semiconductor crystals grown by the vertical Bridgman technique is strongly influenced by the axial and radial variations of temperature within the charge. The relationship between the thermal parameters of the vertical Bridgman system and the thermal behavior of the charge are examined. Thermal models are developed which are capable of producing results expressable in analytical form and which can be used without recourse to extensive computer work for the preliminary thermal design of vertical Bridgman crystal growth systems. These models include the effects of thermal coupling between the furnace and the charge, charge translation rate, charge diameter, thickness and thermal conductivity of the confining crucible, thermal conductivity change and liberation of latent heat at the growth interface, and infinite charge length. The hot and cold zone regions, considered to be at spatially uniform temperatures, are separated by a gradient control region which provides added thermal design flexibility for controlling the temperature variations near the growth interface.

  13. Parameter estimation and sensitivity analysis for a mathematical model with time delays of leukemia

    Science.gov (United States)

    Cândea, Doina; Halanay, Andrei; Rǎdulescu, Rodica; Tǎlmaci, Rodica

    2017-01-01

    We consider a system of nonlinear delay differential equations that describes the interaction between three competing cell populations: healthy, leukemic and anti-leukemia T cells involved in Chronic Myeloid Leukemia (CML) under treatment with Imatinib. The aim of this work is to establish which model parameters are the most important in the success or failure of leukemia remission under treatment using a sensitivity analysis of the model parameters. For the most significant parameters of the model which affect the evolution of CML disease during Imatinib treatment we try to estimate the realistic values using some experimental data. For these parameters, steady states are calculated and their stability is analyzed and biologically interpreted.

  14. Analysis Of Impact Of Various Parameters On BER Performance For IEEE 802.11b

    Directory of Open Access Journals (Sweden)

    Nilesh B. Kalani

    2015-08-01

    Full Text Available Abstract This paper discusses about IEEE 802.11b simulation model implemented using LabVIEW software and its analyses for impact on bit error rate BER for different parameters as channel type channel number data transmission rate and packet size. Audio file is being transmitted processed and analyzed using the model for various parameters. This paper gives analysis of BER verses ESN0 for various parameter like data rate packet size and communication channel for the IEEE 802.11b simulation model generated using LabVIEW. It is proved that BER can be optimized by tweaking different parameters of wireless communication system.

  15. Crystallization and preliminary X-ray diffraction analysis of Salmonella typhimurium uridine phosphorylase complexed with 5-fluorouracil.

    Science.gov (United States)

    Lashkov, A A; Gabdoulkhakov, A G; Shtil, A A; Mikhailov, A M

    2009-06-01

    Uridine phosphorylase (UPh; EC 2.4.2.3) catalyzes the phosphorolytic cleavage of the N-glycosidic bond of uridine to form ribose 1-phosphate and uracil. This enzyme also activates pyrimidine-containing drugs, including 5-fluorouracil (5-FU). In order to better understand the mechanism of the enzyme-drug interaction, the complex of Salmonella typhimurium UPh with 5-FU was cocrystallized using the hanging-drop vapour-diffusion method at 294 K. X-ray diffraction data were collected to 2.2 A resolution. Analysis of these data revealed that the crystal belonged to space group C2, with unit-cell parameters a = 158.26, b = 93.04, c = 149.87 A, alpha = gamma = 90, beta = 90.65 degrees . The solvent content was 45.85% assuming the presence of six hexameric molecules of the complex in the unit cell.

  16. Effects of the crystallization parameters on the fabrication of ultrathin capacitors of PbTiO3

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2010-02-01

    Full Text Available Ultrathin ferroelectric films have interesting potential applications, for example, as transducer elements of nanoelectromechanical systems (NEMS. However, to be integrated in devices, several problems related to their preparation must be solved. In this work we focus on the fabrication of functional capacitors, i.e., without electrical shorts, from PbTiO3 ultrathin films obtained by chemical solution deposition. It has been shown that above a certain grain size to thickness ratio the films break up into isolated structures. Therefore, the control of grain growth by a reduction of the crystallization temperature must be analyzed and the effects on the properties of the ferroelectric films described. With the optimized processing conditions, functional PbTiO3 capacitors of around 40 nm thick with less contribution of leakage currents are obtained.Las láminas ultradelgadas ferroeléctricas tienen aplicaciones potenciales de gran interés, por ejemplo, como elementos transductores de los sistemas nanoelectromecánicos (NEMS. Pero para que puedan ser integradas de manera efectiva en dispositivos reales, varios problemas relacionados con su preparación deben ser resueltos primero. En este trabajo nos centramos en la fabricación de condensadores funcionales, es decir, sin cortos eléctricos, a partir de láminas ultadelgadas de PbTiO3 obtenidas por depósito de disoluciones. Se ha demostrado que por encima de un cierto valor del cociente entre el tamaño de grano y el espesor de la lámina, ésta se separa en estructuras aisladas, perdiendo su continuidad. Por tanto, el control del crecimiento de grano a través de la reducción de la temperatura de cristalización debe ser estudiada, así como sus efectos en las propiedades de las láminas ferroeléctricas. Usando condiciones de procesado óptimas se consiguen preparar condensadores funcionales de PbTiO3 de aproximadamente 40 nm de espesor con una baja contribución de las corrientes de pérdidas.

  17. Rotational analysis of birefringent crystal particles based on modified theory in optical tweezers

    Science.gov (United States)

    Wei, Yong; Zhu, Yanying; Yao, Wenying; Pei, Huan

    2015-04-01

    In order to achieve high-precision, controllable rotation of uniaxial birefringent crystal particles, we study the principle of optical rotation due to the transfer of spin angular momentum from light to birefringent crystal particles. The interaction process between the beam and particles is affected by various factors existed actually, for instance: the reflection of beam on the crystal surface, laser power, the set of angle between the crystal optical axis and surface, radius, phase difference between the ordinary ray and extraordinary ray. According to the analysis of these factors, the theoretical model of optical rotation is reconstructed. The theoretical curves of calcium carbonate and silicon particles chosen as experimental material between the rotational frequency and the radius are simulated and calculated. The result shows that the rotation frequency is inversely proportional to the cube of radius, and compared the performance of modified model with traditional model. The birefringent particles are rotated by optical tweezers in the experiment, and rotation frequency is measured with the same laser power. According to the experimental results of optical rotation, the modified Friese theoretical model is proved to be the reasonably and excellence, in addition, the result shows the maximum frequency of calcium carbonate is 19.1Hz, and the maximum frequency of silicon particles is 11.5Hz. The rationality of our experiment is testified by compared with theoretical analysis. Our study has great directive significance to the design of optical driven micro-mechanical motor and the material selection of rotor.

  18. Crystallization Kinetics of a Solid Oxide Fuel Cell Seal Glass by Differential Thermal Analysis

    Science.gov (United States)

    Bansal, Narottam P.; Gamble, Eleanor A.

    2005-01-01

    Crystallization kinetics of a barium calcium aluminosilicate glass (BCAS), a sealant material for planar solid oxide fuel cells, have been investigated by differential thermal analysis (DTA). From variation of DTA peak maximum temperature with heating rate, the activation energy for glass crystallization was calculated to be 259 kJ/mol. Development of crystalline phases on thermal treatments of the glass at various temperatures has been followed by powder x-ray diffraction. Microstructure and chemical composition of the crystalline phases were investigated by scanning electron microscopy and energy dispersive spectroscopic (EDS) analysis. BaSiO3 and hexacelsian (BaAl2Si2O8) were the primary crystalline phases whereas monoclinic celsian (BaAl2Si2O8) and (Ba(x), Ca(y))SiO4 were also detected as minor phases. Needle-shaped BaSiO3 crystals are formed first, followed by the formation of other phases at longer times of heat treatments. The glass does not fully crystallize even after long term heat treatments at 750 to 900 C.

  19. Response analysis based on smallest interval-set of parameters for structures with uncertainty

    Institute of Scientific and Technical Information of China (English)

    Xiao-jun WANG; Lei WANG; Zhi-ping QIU

    2012-01-01

    An integral analytic process from quantification to propagation based on limited uncertain parameters is investigated to deal with practical engineering problems.A new method by use of the smallest interval-set/hyper-rectangle containing all experimental data is proposed to quantify the parameter uncertainties. With the smallest parameter interval-set,the uncertainty propagation evaluation of the most favorable response and the least favorable response of the structures is studied based on the interval analysis.The relationship between the proposed interval analysis method (IAM) and the classical IAM is discussed.Two numerical examples are presented to demonstrate the feasibility and validity of the proposed method.

  20. A comparative analysis of selected parameters of roofing used in the Polish construction industry

    Directory of Open Access Journals (Sweden)

    Radziszewska-Zielina Elżbieta

    2014-06-01

    Full Text Available Roofing is an important element in the construction of the roof. It is also one of the essential elements of the whole building. The choice of roofing should depend on technical parameters that affect the quality of the materials used and the price. The present paper is a comparative analysis of the properties of five roofing materials selected as examples with respect to twelve parameters. As can be seen from the comparative analysis of the roofing parameters, roofing tile is by far the best material, receiving the highest score in the ranking

  1. Crystallization and preliminary X-ray analysis of a family 19 glycosyl hydrolase from Carica papaya latex

    Energy Technology Data Exchange (ETDEWEB)

    Huet, Joëlle, E-mail: jhuet@ulb.ac.be [Laboratoire de Chimie Générale (CP 206/4), Institut de Pharmacie, Université Libre de Bruxelles (ULB), Campus de la Plaine, Boulevard du Triomphe, B-1050 Bruxelles (Belgium); Azarkan, Mohamed [Laboratoire de Chimie Générale (CP 609), Faculté de Médecine, Université Libre de Bruxelles (ULB), Campus Erasme, 808 Route de Lennik, B-1070 Bruxelles (Belgium); Looze, Yvan [Laboratoire de Chimie Générale (CP 206/4), Institut de Pharmacie, Université Libre de Bruxelles (ULB), Campus de la Plaine, Boulevard du Triomphe, B-1050 Bruxelles (Belgium); Villeret, Vincent [CNRS-UMR 8161, Institut de Biologie de Lille, Université de Lille 1-Université de Lille 2-Institut Pasteur de Lille, IFR142, 1 Rue du Professeur Calmette, F-59021 Lille (France); Wintjens, René, E-mail: jhuet@ulb.ac.be [Laboratoire de Chimie Générale (CP 206/4), Institut de Pharmacie, Université Libre de Bruxelles (ULB), Campus de la Plaine, Boulevard du Triomphe, B-1050 Bruxelles (Belgium)

    2008-05-01

    A chitinase isolated from the latex of the tropical species Carica papaya has been crystallized. The addition of N-acetyl-d-glucosamine to the crystallization solution has improved the diffraction quality resolution of the crystal to 1.8 Å resolution. A chitinase isolated from the latex of the tropical species Carica papaya has been purified to homogeneity and crystallized. This enzyme belongs to glycosyl hydrolase family 19 and exhibits exceptional resistance to proteolysis. The initially observed crystals, which diffracted to a resolution of 2.0 Å, were improved through modification of the crystallization protocol. Well ordered crystals were subsequently obtained using N-acetyl-d-glucosamine, the monomer resulting from the hydrolysis of chitin, as an additive to the crystallization solution. Here, the characterization of a chitinase crystal that belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 69.08, b = 44.79, c = 76.73 Å, β = 95.33° and two molecules per asymmetric unit, is reported. Diffraction data were collected to a resolution of 1.8 Å. Structure refinement is currently in progress.

  2. Sampling the probability distribution of Type Ia Supernova lightcurve parameters in cosmological analysis

    Science.gov (United States)

    Dai, Mi; Wang, Yun

    2016-06-01

    In order to obtain robust cosmological constraints from Type Ia supernova (SN Ia) data, we have applied Markov Chain Monte Carlo (MCMC) to SN Ia lightcurve fitting. We develop a method for sampling the resultant probability density distributions (pdf) of the SN Ia lightcuve parameters in the MCMC likelihood analysis to constrain cosmological parameters, and validate it using simulated data sets. Applying this method to the `joint lightcurve analysis (JLA)' data set of SNe Ia, we find that sampling the SN Ia lightcurve parameter pdf's leads to cosmological parameters closer to that of a flat Universe with a cosmological constant, compared to the usual practice of using only the best-fitting values of the SN Ia lightcurve parameters. Our method will be useful in the use of SN Ia data for precision cosmology.

  3. An improved state-parameter analysis of ecosystem models using data assimilation

    Science.gov (United States)

    Chen, M.; Liu, S.; Tieszen, L.L.; Hollinger, D.Y.

    2008-01-01

    Much of the effort spent in developing data assimilation methods for carbon dynamics analysis has focused on estimating optimal values for either model parameters or state variables. The main weakness of estimating parameter values alone (i.e., without considering state variables) is that all errors from input, output, and model structure are attributed to model parameter uncertainties. On the other hand, the accuracy of estimating state variables may be lowered if the temporal evolution of parameter values is not incorporated. This research develops a smoothed ensemble Kalman filter (SEnKF) by combining ensemble Kalman filter with kernel smoothing technique. SEnKF has following characteristics: (1) to estimate simultaneously the model states and parameters through concatenating unknown parameters and state variables into a joint state vector; (2) to mitigate dramatic, sudden changes of parameter values in parameter sampling and parameter evolution process, and control narrowing of parameter variance which results in filter divergence through adjusting smoothing factor in kernel smoothing algorithm; (3) to assimilate recursively data into the model and thus detect possible time variation of parameters; and (4) to address properly various sources of uncertainties stemming from input, output and parameter uncertainties. The SEnKF is tested by assimilating observed fluxes of carbon dioxide and environmental driving factor data from an AmeriFlux forest station located near Howland, Maine, USA, into a partition eddy flux model. Our analysis demonstrates that model parameters, such as light use efficiency, respiration coefficients, minimum and optimum temperatures for photosynthetic activity, and others, are highly constrained by eddy flux data at daily-to-seasonal time scales. The SEnKF stabilizes parameter values quickly regardless of the initial values of the parameters. Potential ecosystem light use efficiency demonstrates a strong seasonality. Results show that the

  4. Prediction of chemical, physical and sensory data from process parameters for frozen cod using multivariate analysis

    DEFF Research Database (Denmark)

    Bechmann, Iben Ellegaard; Jensen, H.S.; Bøknæs, Niels

    1998-01-01

    Physical, chemical and sensory quality parameters were determined for 115 cod (Gadus morhua) samples stored under varying frozen storage conditions. Five different process parameters (period of frozen storage, frozen storage. temperature, place of catch, season for catching and state of rigor) were...... varied systematically at two levels. The data obtained were evaluated using the multivariate methods, principal component analysis (PCA) and partial least squares (PLS) regression. The PCA models were used to identify which process parameters were actually most important for the quality of the frozen cod....... PLS models that were able to predict the physical, chemical and sensory quality parameters from the process parameters of the frozen raw material were generated. The prediction abilities of the PLS models were good enough to give reasonable results even when the process parameters were characterised...

  5. Tensor methods for parameter estimation and bifurcation analysis of stochastic reaction networks.

    Science.gov (United States)

    Liao, Shuohao; Vejchodský, Tomáš; Erban, Radek

    2015-07-06

    Stochastic modelling of gene regulatory networks provides an indispensable tool for understanding how random events at the molecular level influence cellular functions. A common challenge of stochastic models is to calibrate a large number of model parameters against the experimental data. Another difficulty is to study how the behaviour of a stochastic model depends on its parameters, i.e. whether a change in model parameters can lead to a significant qualitative change in model behaviour (bifurcation). In this paper, tensor-structured parametric analysis (TPA) is developed to address these computational challenges. It is based on recently proposed low-parametric tensor-structured representations of classical matrices and vectors. This approach enables simultaneous computation of the model properties for all parameter values within a parameter space. The TPA is illustrated by studying the parameter estimation, robustness, sensitivity and bifurcation structure in stochastic models of biochemical networks. A Matlab implementation of the TPA is available at http://www.stobifan.org.

  6. Theoretical analysis and experimental research on thermal focal length of a YVO4/Nd:YVO4 composite crystal

    Institute of Scientific and Technical Information of China (English)

    Zhou Cheng

    2009-01-01

    This paper investigates the temperature field distribution and thermal focal length within a laser diode array(LDA)end-pumped YVO4/Nd:YVO4 rectangular composite crystal.A general expression of the temperature field distribution within the Nd:YVO4 rectangular crystal was obtained by analysing the characteristics of the Nd:YVO4 crystal and solving the Poisson equation with boundary conditions.The temperature field distributions in the Nd:YVO4 rectangular crystal for the YVO4/Nd:YVO4 composite crystal and the Nd:YVO4 single crystal are researched respectively.Calculating the thermal focal length within the Nd:YVO4 rectangular crystal was done by an analysis of the additional optical path differences(OPD)caused by heat,which was very identical with experimental results in this paper.Research results show that the maximum relative temperature on the rear face of the Nd:YVO4 crystal in the composite crystal is 150 K and the thermal focal length is 35.7 mm when the output power of the LDA is 22 W.In the same circumstances,the experimental value of the thermal focal length is 37.4 mm.So the relative error between the theoretical analysis and the experimental result is only 4.5%.With the same conditions,the thermal focal length of the Nd:YVO4 single crystal is 18.5 mm.So the relative rate of the thermal focal length between the YVO4/Nd:YVO4 crystal and the Nd:YVO4 crystal is 93%.So,the thermal stability of the output power and the beam quality of the YVO4/Nd:YVO4 laser is more advantageous than the laser with Nd:YVO4 single crystal.

  7. Carboxylic acids in crystallization of macromolecules: learning from successful crystallization experiments.

    Science.gov (United States)

    Offermann, Lesa R; He, John Z; Mank, Nicholas J; Booth, William T; Chruszcz, Maksymilian

    2014-03-01

    The production of macromolecular crystals suitable for structural analysis is one of the most important and limiting steps in the structure determination process. Often, preliminary crystallization trials are performed using hundreds of empirically selected conditions. Carboxylic acids and/or their salts are one of the most popular components of these empirically derived crystallization conditions. Our findings indicate that almost 40 % of entries deposited to the Protein Data Bank (PDB) reporting crystallization conditions contain at least one carboxylic acid. In order to analyze the role of carboxylic acids in macromolecular crystallization, a large-scale analysis of the successful crystallization experiments reported to the PDB was performed. The PDB is currently the largest source of crystallization data, however it is not easily searchable. These complications are due to a combination of a free text format, which is used to capture information on the crystallization experiments, and the inconsistent naming of chemicals used in crystallization experiments. Despite these difficulties, our approach allows for the extraction of over 47,000 crystallization conditions from the PDB. Initially, the selected conditions were investigated to determine which carboxylic acids or their salts are most often present in crystallization solutions. From this group, selected sets of crystallization conditions were analyzed in detail, assessing parameters such as concentration, pH, and precipitant used. Our findings will lead to the design of new crystallization screens focused around carboxylic acids.

  8. Parameter sensitivity and uncertainty analysis for a storm surge and wave model

    Science.gov (United States)

    Bastidas, Luis A.; Knighton, James; Kline, Shaun W.

    2016-09-01

    Development and simulation of synthetic hurricane tracks is a common methodology used to estimate hurricane hazards in the absence of empirical coastal surge and wave observations. Such methods typically rely on numerical models to translate stochastically generated hurricane wind and pressure forcing into coastal surge and wave estimates. The model output uncertainty associated with selection of appropriate model parameters must therefore be addressed. The computational overburden of probabilistic surge hazard estimates is exacerbated by the high dimensionality of numerical surge and wave models. We present a model parameter sensitivity analysis of the Delft3D model for the simulation of hazards posed by Hurricane Bob (1991) utilizing three theoretical wind distributions (NWS23, modified Rankine, and Holland). The sensitive model parameters (of 11 total considered) include wind drag, the depth-induced breaking γB, and the bottom roughness. Several parameters show no sensitivity (threshold depth, eddy viscosity, wave triad parameters, and depth-induced breaking αB) and can therefore be excluded to reduce the computational overburden of probabilistic surge hazard estimates. The sensitive model parameters also demonstrate a large number of interactions between parameters and a nonlinear model response. While model outputs showed sensitivity to several parameters, the ability of these parameters to act as tuning parameters for calibration is somewhat limited as proper model calibration is strongly reliant on accurate wind and pressure forcing data. A comparison of the model performance with forcings from the different wind models is also presented.

  9. Optimization of Process Parameters in Turning of AISI 8620 Steel Using Taguchi and Grey Taguchi Analysis

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Sharma

    2014-03-01

    Full Text Available The aim of this research is to investigate the optimization of cutting parameters (cutting speed, feed rate and depth of cut for surface roughness and metal removal rate in turning of AISI 8620 steel using coated carbide insert. Experiments have been carried out based on Taguchi L9 standard orthogonal array design with three process parameters namely cutting speed, feed rate and depth of cut for surface roughness and metal removal rate. The objective function has been chosen in relation to surface roughness and metal removal rate for quality target. Optimal parameters contribution of the CNC turning operation was obtained via grey relational analysis. The analysis of variance is applied to identify the most significant factor. Experiment with the optimized parameter setting, which has been obtained from the analysis, are giving to validate the results.

  10. MULTI-OBJECTIVE OPTIMIZATION OF EDM PARAMETERS USING GREY RELATION ANALYSIS

    Directory of Open Access Journals (Sweden)

    N. RADHIKA

    2015-01-01

    Full Text Available This paper involves the multi-objective optimization of process parameters of AlSi10Mg/9 wt% alumina/3 wt% graphite in Electrical Discharge Machining for obtaining minimum surface roughness, minimum tool wear rate and maximum material removal rate. The important machining parameters were selected as peak current, flushing pressure and pulse-on time. Experiments were conducted by selecting different operating levels for the three parameters according to Taguchi’s Design of Experiments. The multi-objective optimization was performed using Grey Relation Analysis to determine the optimal solution. The Grey Relation Grade values were then analysed using Analysis of Variance to determine the most contributing input parameter. On analysis it was found that peak current, flushing pressure and pulse-on time had an influence of 61.36%, 17.81% and 8.09% respectively on the optimal solution.

  11. Crystallization and preliminary X-ray diffraction analysis of the diterpene cyclooctatin synthase (CYC) from Streptomyces sp. LZ35

    Science.gov (United States)

    Zhang, Xiulei; Shang, Guijun; Gu, Lichuan; Shen, Yuemao

    2014-01-01

    Terpenoids are a large and highly diverse group of natural products, with the most chemically diverse pool of structures. Terpene synthase is the key enzyme in the process of terpenoid synthesis. In this paper, the first diterpene synthase (CYC) of bacterial origin was successfully crystallized. Native and SeMet-derivative crystals diffracted to 1.75 and 2.6 Å resolution, respectively. The native crystal belonged to space group P212121, with unit-cell parameters a = 59.10, b = 101.73, c = 108.93 Å, and contained two molecules per asymmetric unit. The SeMet-derivative crystal belonged to space group P21, with unit-cell parameters a = 58.64, b = 109.47, c = 58.73 Å, β = 119.35°, and had two molecules per asymmetric unit. PMID:24598929

  12. Crystallization and preliminary X-ray analysis of monalysin, a novel β-pore-forming toxin from the entomopathogen Pseudomonas entomophila.

    Science.gov (United States)

    Blemont, Maryline; Vincentelli, Renaud; Kellenberger, Christine; Opota, Onya; Lemaitre, Bruno; Roussel, Alain; Leone, Philippe

    2013-08-01

    Monalysin was recently described as a novel pore-forming toxin (PFT) secreted by the Drosophila pathogen Pseudomonas entomophila. Recombinant monalysin is multimeric in solution, whereas PFTs are supposed to be monomeric until target membrane association. Monalysin crystals were obtained by the hanging-drop vapour-diffusion method using PEG 8000 as precipitant. Preliminary X-ray diffraction analysis revealed that monalysin crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 162.4, b = 146.2, c = 144.4 Å, β = 122.8°, and diffracted to 2.85 Å resolution using synchrotron radiation. Patterson self-rotation analysis and Matthews coefficient calculation indicate that the asymmetric unit contains nine copies of monalysin. Heavy-atom derivative data were collected and a Ta6Br14 cluster derivative data set confirmed the presence of ninefold noncrystallographic symmetry.

  13. Dual parameter analysis of CsI:Tl/PMT with a digital oscilloscope

    CERN Document Server

    Devol, T A; Fjeld, R A

    1999-01-01

    Scintillation pulses from alpha-particle and gamma-ray excited CsI:Tl were recorded with a photomultiplier tube and digital oscilloscope card in single parameter (pulse shape or pulse height) and dual parameter (simultaneous pulse shape and pulse height) modes. A 2.8x1.3x1.3 cm sup 3 CsI:Tl crystal was coupled to a Burle 8850 photomultiplier tube (PMT) and excited with sup 1 sup 4 sup 8 Gd (E subalpha=3.18 MeV) and sup 1 sup 3 sup 7 Cs (E subgamma=0.662 MeV). The timing pulses (50 OMEGA terminated dynode signal) from the PMT base were directly input to a GaGe CompuScope 8012A/PCI sup T sup M (12-bit, 50 MHz dual channel digital oscilloscope card) that resided in a P6-300 MHz personal computer. Individual digitized pulses were processed via a LabVIEW sup T sup M V 4.1 interface to the oscilloscope. The ratio of the charge collected over a short time interval to the total charge collected was used for the single parameter pulse shape spectrum while the total charge collected was used for the single parameter pu...

  14. Non-destructive analysis of didymium and praseodymium molybdate crystals using energy dispersive X-ray fluorescence technique

    Science.gov (United States)

    Bhat, C. K.; Joseph, Daisy; Pandita, Sanjay; Kotru, P. N.

    2016-08-01

    Analysis of didymium (Di) and praseodymium molybdate crystals were carried out using energy dispersive X-ray fluorescence (EDXRF). The assigned empirical chemical formulae of the composites were tested and verified by the EDXRF technique by estimating experimental major elemental concentration ratios. On the Basis of these ratios, the established formulae for some of the composite materials have been verified and suggestions made for their refinement. Non-destructive technique used in this analysis enables to retain the original crystal samples and makes rapid simultaneous scan of major elements such as La, Pr, Ned and Mo as well as impurities such as Ce. Absence of samarium(Sm) in the spectrum during analysis of didymium molybdate crystals indicated an incomplete growth of mixed rare earth single crystal. These crystals (e.g.,Di) are shown to be of modified stoichiometry with Ce as trace impurity.

  15. Crystallization and preliminary X-ray crystallographic analysis of the sclerostin-neutralizing Fab AbD09097.

    Science.gov (United States)

    Boschert, Verena; Muth, Eva Maria; Knappik, Achim; Frisch, Christian; Mueller, Thomas D

    2015-04-01

    The secreted cystine-knot protein sclerostin was first identified from genetic screening of patients suffering from the rare bone-overgrowth diseases sclerosteosis and van Buchem disease. Sclerostin acts a negative regulator of bone growth through inhibiting the canonical Wnt signalling cascade by binding to and blocking the Wnt co-receptor LRP5/6. Its function in blocking osteoblastogenesis makes it an important target for osteoanabolic therapy approaches to treat osteoporosis, which is characterized by a progressive decrease in bone mass and density. In this work, the production, crystallization and preliminary X-ray diffraction data analysis of a sclerostin-neutralizing human Fab antibody fragment, AbD09097, obtained from a naive antibody library are reported. Crystals of the Fab AbD09097 belonged to space group P21, with unit-cell parameters a = 45.19, b = 78.49, c = 59.20 Å, β = 95.71° and diffracted X-rays to a resolution of 1.8 Å.

  16. Analysis of cutoff frequency in a one-dimensional superconductor-metamaterial photonic crystal

    Science.gov (United States)

    Aly, Arafa H.; Aghajamali, Alireza; Elsayed, Hussein A.; Mobarak, Mohamed

    2016-09-01

    In this paper, using the two-fluid model and the characteristic matrix method, we investigate the transmission characteristics of the one-dimensional photonic crystal. Our structure composed of the layers of low-temperature superconductor material (NbN) and double-negative metamaterial. We target studying the effect of many parameters such as the thickness of the superconductor material, the thickness of the metamaterial layer, and the operating temperature. We show that the cut-off frequency can be tuned efficiently by the operating temperature as well as the thicknesses of the constituent materials.

  17. Numerical analysis of dislocation density and residual stress in a GaN single crystal during the cooling process

    Science.gov (United States)

    Nakano, S.; Gao, B.; Kakimoto, K.

    2017-06-01

    In this study, we investigate the influence of thermal stress on the dislocation density and residual stress in GaN single crystals by numerical analysis. The results show that the dislocation density increases, but the thermal stress does not decrease, and the residual stress increases throughout the cooling process. The reason for this phenomenon is that the dislocation density is higher at the periphery of the crystal and distribution of dislocation density in the crystal is inhomogeneous. Then, the increase of dislocation does not allow the thermal stress on the entire crystal to relax.

  18. Crystallization and X-ray analysis of the extracellular adhesion domain of Helicobacter pylori adhesin A: the significance of the cation composition in the crystallization precipitant.

    Science.gov (United States)

    Guo, Ling; Zhang, Jinyong; Cui, Liwei; Liu, Dong; Ma, Bo; Wang, Shufeng; Li, Haibo; Wu, Yuzhang; Liu, Wei

    2017-04-01

    Adherence to host cells is a crucial step in the process of bacterial infection, which is usually mediated by a number of outer membrane proteins identified as adhesins. Helicobacter pylori adhesin A (HpaA) is a member of the adhesin family that mediates the adherence of Helicobacter pylori to gastric epithelial cells, and consequently assists the bacteria in becoming a life-long colonizer of the human stomach. In this study, two constructs were made for the production of truncated HpaA proteins comprising residues 31-260 and 53-260, respectively. The products of both constructs were crystallized, but only the protein from the shorter construct (residues 53-260) formed crystals that were capable of diffraction. In the subsequent optimization trials, crystals in different forms were unexpectedly obtained by using lithium sulfate and ammonium sulfate as the precipitant. An X-ray data set was collected to 1.95 Å resolution on beamline BL18U1 at SSRF using a crystal grown with 1.92 M lithium sulfate, which belonged to space group P65 with unit-cell parameters a = b = 95.42, c = 54.72 Å, γ = 120°, while another crystal grown with 1.9 M ammonium sulfate diffracted to 2.60 Å resolution and the collected data set was indexed in space group P21212, with unit-cell parameters a = 121.01, b = 190.56, c = 106.31 Å. The collection of diffraction data has established a solid basis for structure determination.

  19. Ab-initio crystal structure analysis and refinement approaches of oligo p-benzamides based on electron diffraction data

    DEFF Research Database (Denmark)

    Gorelik, Tatiana E; van de Streek, Jacco; Kilbinger, Andreas F M

    2012-01-01

    Ab-initio crystal structure analysis of organic materials from electron diffraction data is presented. The data were collected using the automated electron diffraction tomography (ADT) technique. The structure solution and refinement route is first validated on the basis of the known crystal stru...

  20. Crystallization and preliminary X-ray diffraction analysis on the homing endonuclease I-Dmo-I in complex with its target DNA

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Pilar [Macromolecular Crystallography Group, Structural Biology and Biocomputing Programme, Spanish National Cancer Centre (CNIO), c/Melchor Fdez. Almagro 3, 28029 Madrid (Spain); Prieto, Jesús; Ramos, Elena; Blanco, Francisco J. [NMR Group, Structural Biology and Biocomputing Programme, Spanish National Cancer Centre (CNIO), c/Melchor Fdez. Almagro 3, 28029 Madrid (Spain); Montoya, Guillermo, E-mail: gmontoya@cnio.es [Macromolecular Crystallography Group, Structural Biology and Biocomputing Programme, Spanish National Cancer Centre (CNIO), c/Melchor Fdez. Almagro 3, 28029 Madrid (Spain)

    2007-12-01

    I-Dmo-I is a well characterized homing endonuclease from the archaeon Desulfurococcus mobilis. The enzyme was cloned and overexpressed in Escherichia coli. Crystallization experiments of I-Dmo-I in complex with its DNA target in the presence of Ca{sup 2+} and Mg{sup 2+} yielded crystals that were suitable for X-ray diffraction analysis. Homing endonucleases are highly specific DNA-cleaving enzymes that recognize long stretches of base pairs. The availability of these enzymes has opened novel perspectives for genome engineering in a wide range of fields, including gene therapy, by taking advantage of the homologous gene-targeting enhancement induced by a double-strand break. I-Dmo-I is a well characterized homing endonuclease from the archaeon Desulfurococcus mobilis. The enzyme was cloned and overexpressed in Escherichia coli. Crystallization experiments of I-Dmo-I in complex with its DNA target in the presence of Ca{sup 2+} and Mg{sup 2+} yielded crystals that were suitable for X-ray diffraction analysis. The crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 106.75, b = 70.18, c = 106.85 Å, α = γ = 90, β = 119.93°. The self-rotation function and the Matthews coefficient suggested the presence of three protein–DNA complexes per asymmetric unit. The crystals diffracted to a resolution limit of 2.6 Å using synchrotron radiation at the Swiss Light Source (SLS) and the European Synchrotron Radiation Facility (ESRF)