bluuebunny/crossref_metadata_2025 huggingface dataset:
Powder Diffraction Data for Two Energetic Materials and a Proposed Intensity Figure of Merit
Authors: Lowe-Ma Charlotte K.
Published: January 2013

Indexed X-ray powder diffraction data are reported for two energetic materials, oxalylhydroxamic acid and 2-diazo-4, 6-dinitrophenol (DDNP). For these two compounds, powder diffraction data calculated from single-crystal structure determinations are also presented and compared to the experimentally observed powder diffraction data. To evaluate the reliability of the experimentally obtained intensities, an intensity figure of merit, IX(N), based on an average percent difference between observed and calculated intensities for a limited number of strong and moderately-strong lines is proposed as a more useful measure of agreement than R1. For N lines with Icalc > X% relative intensity, IX(N) is defined as

This is compared to

which involves a summation over all lines.
QPDA – A User-Friendly, Interactive Program for Quantitative Phase and Crystal Size/Strain Analysis of Powder Diffraction Data
Authors: Madsen I.C. , Hill R.J.
Published: January 2013

Recent developments in the Rietveld method for the analysis of powder diffraction data have seen the method evolve from its original purpose of crystal structure refinement to nclude the determination of phase abundance in polycrysalline mixtures and the estimation of crystal size and strain parameters. However, the Rietveld method is not easy to use and may deter many powder diffractionists, who are not inerested in structure refinement per se, from using the method in its non-structural applications.

In order to overcome the difficulties in using the Rietveld method, a program, QPDA (for Quantitative Powder Diffraction Analysis), has been written that sets the conditions necessary for a single or multi-phase refinement, runs the Rietveld program and extracts phase abundance and size/strain information from the refined parameters. The program comprises a user-friendly, default-driven system of subroutines, written initially in VAX Fortran, and operates from a database of inorganic materials frequently encountered in a wide range of minerals and materials science industries.

Equations (3) and (5) should be corrected to read as follows:
General Expression of Quantitative Phase Analysis for Samples Containing Amorphous Phase
Authors: Wang Shao-Dong , Pu Xin-Cheng
Published: January 2013

A general expression for the method of QXRPD without standards is given in this paper to solve the problem of phase analysis on samples containing a non-crystalline component. Its application to some specific cases is discussed. The experiments have proved successful in the analysis of cement and sand-lime samples. The technique may also be applicable for the analysis of fly-ash, glass, ceramics, and metals. It is especially convenient in the study of kinetics and mechanism of reactions when the chemical composition of all samples does not change, because it is not necessary to know the mass absorption coefficient of samples. In the mathematical treatment of non-linear equations given in this paper, a method called linearized iteration procedure is first presented by the author.
A Powder Diffractometry Study of γ'-Phase Formation
Authors: Ariely S. , Kimmel G. , Dirnfeld S. F. , Bamberger M. , Prinz B.
Published: January 2013

The kinetics of γ'-phase formation in a Ni-base superalloy were studied. The data (pairs of cps and 2θ) were processed by the deconvolution program (Wiedemann, Unnam and Clark, 1987), which was rewritten in FORTRAN and installed on an IBM/VM and a VAX/VMS host computer. Optimal program parameters were found. Pure nickel was used as a standard. The only evidence obtained from the raw data is that the early stage of the aging process is accompanied by broadening. Deconvolution resolved the peaks into three kinds of diffraction lines: Ni(γ), precipitate (γ'), and undefined lines which have been interpreted as satellites. The results show that our X-ray diffraction lines are composed of the main diffraction lines of nickel-base A1 type alloy and additive satellites. In an advanced stage of aging the satellites assume the typical diffraction pattern of γ' phase.
X-Ray Diffraction Analysis of Strontium in Barites
Authors: Soriano M.C. Osácar , Ráfales J. Besteiro , Martínez J. González
Published: January 2013

A procedure for Sr-analysis of vein barites by X-ray powder diffraction is described. It is based on the measurement of barite d210 spacing change referenced to NaCl as the internal standard. This procedure covers a range of Sr isomorphic substitution of 0 to 12% SrSO4. Comparison with other values, derived from literature data, shows they are in good agreement with the experimental ones. Statistical analysis of the results yields a maximum absolute error of ±0.50 %SrSO4 in Sr determination. This measurement error proves to be acceptable for most studies of barite in mineral deposits. The effect of Pb-substitution is smaller, in most cases, than this error.

The reported method has the advantage of being fast and simple. It can routinely handle large number of samples as well as small samples isolated from large crystals. Moreover, it allows the recovery of the original sample after the analysis by dissolving the NaCl in water. The main disadvantage is that fair amounts of quartz interfere with the measurement of the position of the barite 210 line.
Quantitative Analysis of a Textured Coating by a New X-Ray Diffraction Method
Authors: Gu Mingyuan , Marder A.R.
Published: January 2013

An iterative external standard method of X-ray diffraction is presented to overcome the difficulties of preferred orientation and peak overlap encountered in quantitative phase analysis. Instead of using only a single line intensity in the traditional external standard technique, all the reflection data are used in the calculation. The accuracy and applicability of this method was tested on a series of two-phase powder mixtures with known composition. The results show markedly good agreement with the actual values. As an example, the analysis was applied to the data collected from an as plated electrodeposited Zn-Fe coating. The determined phase composition of the coating was found to be 88.2 +/− 5.3 wt % δ-phase and 11.8 +/− 0.7 wt % η -phase.
X-Ray Powder Diffraction Data for 2,2′,2″-triaminotriethylamine-trihydrochloride
Authors: Lundtoft Britta , Rasmussen Svend Erik
Published: January 2013

X-ray powder diffraction data for the compound 2,2′,2″-triaminotriethylamine-trihydrochloride, N-(CH2−CH2−NH2)3(HCL)3are reported. The crystals are cubic and the space group is P213 with a = 10.8734(12) Å. Dx= 1.320Mg/m3. The data were obtained both by photographic and diffractometric methods.
Permanent Samples for Guinier Cameras
Authors: Sperling Z.
Published: January 2013

A technique is described for the preparation of Guinier camera samples which are permanent and can be stored indefinitely in microslide file cases.
Powder Diffraction Data for Nitroguanidine, C(NH2)2NNO2
Authors: Vasil'ev E.K. , Sapozhnivov A.N. , Dobronravova Z.A. , Vereshchagin L.I.
Published: January 2013

A powder diffraction pattern and unit cell data for nitroguanidine, C(NH2)2NNO2 are presented. The orthorhombic space group Fdd2 (43) has been confirmed by single crystal methods.
Crystal Data and Solid-Liquid Transformation Study by DSC of 2 Hydroxymethyl-2 methyl-1,3 propanediol tetrahydrate
Authors: Laügt M. , Teisseire M. , Guion J.
Published: January 2013

2 Hydroxymethyl-2 methyl-1,3 propanediol tetrahydrate has been crystallised from aqueous solutions in the form of transparent tetragonal thin plates. The cell parameters of the unit cell were determined as a = 9.102(1) Å, c = 47.654(6) Å and the space group is I41/ a.

Solid liquid and reverse transformations have been studied by DSC, and a melting enthalpy of 185 kJ.kg−1 at 29.8° C determined.
Refinement of the Structure of MnSi by Powder Diffraction
Authors: Jørgensen Jens-Erik , Rasmussen Svend Erik
Published: January 2013

Crystal data and results of structure refinements for MnSi are reported. The material is cubic, P213, with a = 4.5603(2) Å, Vd = 94.84(1) Å3, Z = 4, Dx = 5.815 Mg/m3. Intensity data were obtained from a Stoe transmission type diffractometer equipped with a position sensitive detector. CuKα1 radiation, λ = 1.5405981 Å was employed. Germanium was used as an internal standard for the determination of the lattice constant (aGe= 5.6582 Å). The structure was refined by the Rietveld method by aid of three different programs.
Crystal and X-Ray Powder Data for a New Organic Diphosphate [NH3(CH2)2NH3]2·P207
Authors: Kamoun Slaheddine
Published: January 2013

With the help of Boulle's metathesis reaction, we have succeeded in preparing the compound [NH3(CH2)2NH3]2·P207. We describe its chemical preparation and main crystallographic features. The bis(ethylenediammonium) diphosphate salt is monoclinic, space group C2/c, with Z = 4. Unit cell parameters and powder diffraction data for this salt are reported.
Geometrical factors for correction of intensities in Seemann–Bohlin diffractometry
Authors: Černý R. , Kupčík V.
Published: January 2013

The correct formulas for geometrical factors for correction of diffracted intensities in Seemann-Bohlin diffractometry were tested. A Huber 653 goniometer, gold and titanium nitride layers, white tin, and rutile as specimens were used in the reflection mode. A Huber 642 goniometer and olivine as a specimen were used in the transmission mode. It was found that, due to a variable specimen-detector distance during 2θ scan, the variable efficiency of the Soller slits in the diffracted beam must be taken into account. The model describing this effect analytically is presented. As a final test the structures of white tin, rutile, and olivine were refined from the measured data corrected for different factors.
X-ray diffraction analysis of the cause of catalyst deactivation
Authors: Radović Vjera Novosel
Published: January 2013

After regeneration, the catalyst UOP-R-62 was used for conversion of reforming benzine. The percentage of conversion benzine fraction was considerably smaller than that of the new catalyst sample. To determine the cause of catalyst deactivation, in addition to standard methods of analysis, X-ray diffraction and scanning electron microscopy were used. Real and model samples of UOP-R-62 were analysed. Real samples were prepared with the new catalyst, a used and regenerated catalyst with good activity and a deactivated catalyst. Model samples were prepared from the new catalyst by heating at 400–1100 °C in a porcelain crucible in a muffle furnace for 1 h. Prepared samples were measured in a Philips diffractometer system and examined in a scanning electron microscope. The obtained diffractometer patterns, FWHM value of the 440 reflection of γAl2O3, electron micrographs and images of emitted characteristic X-rays were mutually compared. Only the values obtained from the deactivated catalyst differed from the others. Besides reduced broadening of the 440 line the material exhibited new X-ray diffraction lines, a change in phase composition, and modifications in morphology and microstructure. These changes are an indication that overheating of individual spheres of catalyst UOP-R-62 to a temperature of 700—1100 °C or higher caused their deactivation.
A quantitative X-ray powder diffraction analysis of the Li2O–SiO2glass–ceramic system
Authors: Tomlin D. W. , Sullenger D. B. , Cantrell J. S.
Published: January 2013

An X-ray powder diffraction quantitative analysis has been developed to determine the relative amounts of the principal crystalline phases (α-Li2SiO3,α-Li2Si2O5and theα-cristobalite form of SiO2) contained in selected Li2O–SiO2glass-ceramics. The analysis was extended to estimate the amorphous-to-crystalline content ratio of individual samples. The method utilized is an external-standard intensity ratio technique that employs cristobalite, a component common to each sample, for a standard.
High-temperature X-ray powder diffractometry of the decomposition of zirconium hydroxide nitrates
Authors: Bénard Patricia , Auffrédic Jean Paul , Louër Daniel
Published: January 2013

The decomposition reactions of two zirconium hydroxide nitrates Zr(OH)2(NO3)2·(4+x)H2O and α-Zr(OH)2 (NO3)2·(1+x)H2O (0≤x≤1) have been studied by thermogravimetric analysis and high-temperature X-ray powder diffractometry (HTXRD), in nitrogen gas environment. The decomposition reaction sequences were clearly displayed by the HTXRD technique. They are different for the two precursors, except the formation of amorphous zirconia at low temperature (200 °C) and crystalline zirconia at about 390 °C. Three modifications of Zr(OH)2(NO3)2·H2O (α,β,γ) were identified. Their X-ray powder diffraction patterns were indexed by the successive dichotomy method. The unit cells are triclinic and present some parametric and volumetric similarities from each other and also with that of their precursor. Moreover, the thermal decomposition sequences of Zr(OH)2(NO3)2·(4+x)H2O and α-Zr(OH)2(NO3)2·(1+x)H2O include the formation of anhydrous oxide nitrate ZrO(NO3)2 and anhydrous hydroxide nitrate Zr(OH)2(NO3)2, respectively.
Synthesis and powder data for [Mn(H2O)]0.25(VO)0.75PO4·2H2O
Authors: Beneš Ludvík , Richtrova Klára , Votinský Jiři , Kalousová Jaroslava , Zima Vítěslav
Published: January 2013

A new compound [Mn(H2O)]0.25(VO)0.75PO4·2H2O was prepared by the reaction of V2O5 with the boiling aqueous solution of H3PO4 and KMnO4. The reaction product is a yellow-brown powder, stable in air. The tetragonal unit-cell parameters (298 K) are a = 6.2034(2)Å, c = 13.814(1)Å, V = 531.59Å3, Z = 4, Mr = 194.94, Dx = 2.493 g/cm3, Dexp = 2.52 g/cm3. X-ray (CoKα radiation) powder diffraction data (35 lines) are reported. The compound's structure is probably derived from the VOPO4·2H2O layered lattice by substitution of [Mn(H2O)]3+ ions for a quarter of the vanadyl groups VO3+. Practically the same powder data and unit-cell parameters were found for [Mn(H2O)]x(VO)1−xPO4·2H2O, where x ranges from 0.185 to 0.25.
X-ray and neutron powder diffraction studies of NiFeGaO4 and ZnFeGaO4
Authors: Maayouf R. M. A. , Brokmeier H.-G. , Fayek M. K. , WÖhlert S.
Published: January 2013

The title compounds crystallize in the cubic space group Fd3m, Z = 8, with cell parameters of 8.2958(37) Å for NiFeGaO4 and 8.3921(24) Å for ZnFeGaO4. By comparison of experimental and calculated patterns with various site distribution models, ZnFeGaO4 has been determined to have the normal spinel structure and NiFeGaO4 a dominantly inverse spinel structure.
X-ray powder diffraction data for some manganese phosphates and arsenates
Authors: Aranda Miguel A. G.
Published: January 2013

Eight phosphates and arsenates of manganese have been synthesized and examined using powder X-ray diffraction in order to update or extend the current powder diffraction data files. The studied compounds are MnPO4·H2O, MnAsO4·H2O, LiMnPO4(OH) LiMnAsO4(OH), LiMnAsO4, Mn2As2O7) MnAsO4, and Mn(PO3)3. The powder patterns have been indexed and the cell data are reported.
New X-ray powder diffraction data for trilithium octaoxodihydroxopentaborate Li3B5O8(OH)2
Authors: Touboul M. , Bétourné E.
Published: January 2013

Precise X-ray powder diffraction patterns for the tetragonal form of Li3B5O8(OH)2 were obtained using a Huber camera; photographs were taken at 22 °C with CuKα1 radiation (λ =1.5406 Å) and with Si as internal standard (a = 5.4308 Å). Refinements of indexed reflections yielded the following parameters: a = 6.8455(4)Å, c = 14.551(1)Å, space group P41212, Z = 4, Dx = 2.31, and Dm = 2.28 g/cm3. The Smith–Snyder figure of merit of F30 = 97(O.OO7,45) compares to that of F30 = 2.6(0.206,57) reported for the existing pattern in the Powder Diffraction File (34-1070).
X-ray data for triammonium citrate
Authors: Venkateshwarlu M. , Hussain K. A. , Rao T. Bhaskar
Published: January 2013

The lattice parameters of triammonium citrate, (NH4)3C6H5O7, were determined by X-ray single crystal and powder diffraction methods. The crystal structure is orthorhombic with a = 6.187 ± 0.001 Å, b = 14.803 ± 0.004 Å, and c = 10.826 ± 0.003 Å, and from the systematic absences, the space group is Pcc2 ().
The Crystal Structure of K2REZr(PO4)3(RE = Y, Gd) Isotypic with Langbeinite
Authors: Wulff H. , Guth U. , Loescher B.
Published: January 2013

K2YZr(PO4)3and K2GdZr(PO4)3were found to have the langbeinite-type structure (K2Mg2(SO4)3). We determined the crystal structure of these compounds from powder diffraction data. They are cubic P213 (no. 198), with a = 10.3346(1)Å and a = 10.3457(3)Å respectively. The intensity values we observed and calculated are reported. Intensity measurements indicate a random distribution of Y3+(Gd3+) and Zr4+on both Mg2+sites of langbeinite.
The ICDD/PDF Coverage of the High Tc Superconductor and Related Compounds in the A-R-Cu-O Systems (A = Ba, Sr and Ca, and R = Lanthanides and Y)
Authors: Wong-Ng Winnie
Published: January 2013

A compilation has been made of the X-ray powder diffraction patterns of the high Tc superconductor and related phases in the systems of Ba-R-Cu-O, Sr-R-Cu-O and Ca-R-Cu-O, where R = yttrium and lanthanides. In addition to the patterns of compounds found in these systems, other related compounds included are cation substitution products of the high Tc phases of Ba2RCu2O6+x, potential reaction products with different types of sample containers, and selected thin-film substrates. The International Centre for Diffraction Data/Powder Diffraction file (ICDD/PDF) coverage includes Sets 1 to 41. A cross correlation of these phases with those reported in Phase Diagrams For Ceramists (PDFC), has also been completed. Results of these efforts are tabulated.
On Indexing X-Ray Diffraction Powder Patterns of Cubic Lazurites with an Incommensurate-Modulated Structure
Authors: Sapozhnikov A.N. , Vasil'ev E.K. , Bayliss P.
Published: January 2013

The modulation of the lazurite structure has been determined by X-ray diffraction methods. The indexing of satellites on X-ray diffraction powder patterns has been made by means of single crystal X-ray diffraction patterns. The irrationality of the satellite distance from the basic reflections in some specimens of isotropic lazurite confirms the incommensurability of the wavelength of modulation by an edge magnitude of the sodalite subcell and the necessity of a fractional mineral lattice. X-ray diffraction powder data of lazurites with different periods of incommensurate-modulated structure are established. Modulation structure parameters are 0.217 and 0.175, respectively. Indexing of X-ray diffraction powder data of cubic Baikal lazurite suggested by the PDF editorial staff is considered.
A Geometric Factor for Asymmetric Diffraction
Authors: Dragoi Danut
Published: January 2013

In many experiments on X-ray stress analysis, the tilt angle Ψ shows that for a given peak the integrated intensity function of Ψ is not a constant. In this paper a geometric factor is described which corrects the integrated intensity in asymmetric X-ray diffraction. The defocussing effect, always present in asymmetric X-ray diffraction, reduces the number of diffracted X-ray photons registered by the detector. For a θ/2θ diffractometer, the new correction was found to be dependent on the divergence angle of source and detector slit, the tilt angle Ψ and the Bragg angle θ.

The experimental results corrected with the proposed factor are in good agreement with the theory in limits of acceptable errors.
The Use of a Post Diffraction Curved Germanium Monochromator with a Bragg-Brentano Type Powder Diffractometer
Authors: Rasmussen Svend Erik
Published: January 2013

Pyrolytic graphite is frequently used as a post diffraction monochromator with powder diffractometers of the Bragg-Brentano type. Curved graphite monochromators yield high intensities and suppress efficiently fluorescent radiation except from the element which is the same as the target element of the X-ray tube. They are not, however, able to separate the Kα1 line from the Kα2 component with the X-ray targets normally used in powder diffraction. Crystals with smaller mosaic spread than graphite are needed for selecting a pure Kα1 line. Commercially available crystals which are suitable for this purpose are asymmetrically cut curved quartz and germanium monochromators of the Johansson type. Experiments have been carried out in this laboratory with two quartz monochromators and one germanium monochromator.
Crystal Data for Complexes of Co(II) and Ni(II) Perchlorates with Mepirizole
Authors: Amigó J.M. , Ochando L.E. , Reventós M.M. , García-Lozano J. , Soto-Tuero L.
Published: January 2013

Metal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.
A FORTRAN Program for Conversion of PC-APD Data Files into ASCII Files
Authors: Karanović Lj. , Poleti D.
Published: January 2013

Recently, Dahan and co-workers (Dahan, 1991) suggested processing the XRD data by spreadsheet computer programs. Treated in this manner the XRD data became very flexible and made comparison with other data sets, as well as graphical presentation, much easier. In this note a simple FORTRAN 77 program for conversion of PC-APD data files into ASCII files suitable for import into spreadsheets is reported.

In our laboratory XRD data are collected on a Philips 1710 diffractometer operated by the PC-APD version 2.0 (PC-APD Software, 1989). Each experiment usually generates its files containing collected raw intensity data (.RD file), background data (.BK file) and file with peak positions and their intensities (.DI file). The XRD data can be further processed: after smoothing, data are stored in files with extension .SM (.SM file) and, after Kα2 stripping, into files with extension .A2 (.A2 file). All files are stored in the binary format.
The Use of Reference Intensity Ratios in X-Ray Quantitative Analysis
Authors: Snyder Robert L.
Published: January 2013

Each of the RIR based methods for carrying out quantitative X-ray powder diffraction analysis are described and a consistent set of notation is developed. The so called “standardless” analysis procedures are shown to be a special case of the internal-standard method of analysis where the normalizing assumption is used. All analytical methods, other than the Rietveld whole pattern matching procedure, require the use of explicitly measured standards, typically in the form of RIR values. However, if only semi-quantitative results can be tolerated, the standards may be obtained by using published RIR and relative intensity values. The exciting new techniques of whole pattern fitting and Rietveld constrained quantitative analysis are also described in RIR notation and shown also to be forms of the internal-standard method with the normalization assumption. The quantitative results obtained from Rietveld quantitative analysis are derived from computed standards in the form of computed, normalized, RIRN values. The normalization assumption in Rietveld analysis allows the exclusive use of computed standards and comes as close to a “standardless” analysis as one can achieve: relying on the absence of amorphous material and on the validity of the structural models. Relationships are given for obtaining quantitative analysis from these RIRN values obtainable from the least-squares scale factors.
Simultaneous Determination of Layer Thickness, Composition, and Mass Absorption by X-Ray Diffraction
Authors: Battaglia Stefano , Franzini Marco , Leoni Leonardo
Published: January 2013

This paper describes a new method for the simultaneous determination of mineral composition, mass thickness and mass absorption coefficient of a thin layer of a crystalline substance deposited on a crystalline substrate.

The samples were deposited on membrane disc filters, consisting of mixtures of cellulose acetate and cellulose nitrate. Quantitative results are achieved by measuring the diffraction intensity of the analyte and the attenuation of a reflection of the crystalline material supporting the deposited sample. The mean accuracy of the analysis was found to be: ≈ 3% for mass thickness, ≈ 1% for mass absorption coefficient and ≈ 4% for quantitative mineralogical determination.
X-Ray Determination of a Crystal System
Authors: Runge C.
Published: January 2013

The Debye Scherrer method (1917) of determining a crystal system by observation of X-ray interferences on randomly oriented crystal particles amounts in the mathematical problem to deriving quadratic equations for three variables from unknown integer multiples of these variables. In my opinion it is not only physically, but also mathematically reasonable to treat this problem from a geometrical point of view. Let L,M, and N be three non-parallel vectors. Vectors P can be derived by multiplication with the integers n1, n2 and n3, so that

P = n1L + n2 M + n3 N.
Crystal Structure of the High-Temperature Phase of a Compound Sr2ZnWO6
Authors: Zhengmin Fu , Wenxiu Li
Published: January 2013

The crystal structure of the high-temperature phase of Sr2ZnWO6 prepared by air quenching from 1200° C has been determined by means of X-ray powder diffraction. β-Sr2ZnWO6 belongs to the cubic system, with space group Fm3m and a lattice parameter a = 7.9266 Å at room temperature. Its measured density is Dm = 6.93g/cm3, and each unit cell contains four formula weights.
Influence of thermal expansion on the lattice parameter of silicon
Authors: Liu Fengchao
Published: January 2013

Considering the thermal expansion of silicon at ambient conditions, the lattice parameter will change 0.00032 Å for a 10 °C range. This range is measurable with modern diffraction instrumentation illustrating the importance of knowing the accurate lattice parameter, the temperature of measurement, and the thermal expansion coefficient. The best value for the expansion coefficient is 2.45×10−6/°C.
KCr3(SO4)2(OH)6: Synthesis, characterization, powder diffraction data, and structure refinement by the Rietveld technique and a compilation of alunite-type compounds
Authors: Lengauer C. L. , Giester G. , Irran E.
Published: January 2013

The new compound, KCr3(SO4)2(OH)6, was prepared by low-hydrothermal synthesis. The structure was refined by the Rietveld technique in space group(Z= 3),a=7.2416(3) Å,c= 17.0788(9) Å,V= 775.63 Å3,Rp= 7.7,Rwp=10.1,RB= 6.8. The compound is isotypic with alunite, KAl3(SO4)2(OH)6. The temperature of decomposition under nitrogen atmosphere to a hitherto unknown form is about 550 K. The water content of alunite-type compounds is discussed.
Refinement of unit-cell parameters by whole-powder-pattern fitting technique
Authors: Toraya H. , Ochiai T.
Published: January 2013

The accuracy of the unit-cell parameters refined by using the whole-powder-pattern decomposition method is discussed. Powders of W, ZnO, TiO2, BaTiO3 Mg2SiO4, Al2SiO5 (+α-SiO2), and monoclinic ZrO2 were used as test samples. Two internal standard reference materials of Si and CeO2 and two types of powder diffractometers were used for data collections. The systematic peak-shift was corrected by determining the unit-cell parameters and the error function simultaneously during the whole-pattern-fitting. The estimated standard deviations for sample means ranged from <10 ppm (10−6) in cubic symmetry to 20∼50 ppm in monoclinic symmetry. These analyses could be carried out almost automatically in a computation time of less than l min for each sample on a workstation. The use of symmetric experimental profiles, obtained by the suppression of axial divergence, is very effective and of essential importance for improving the accuracy of unit-cell parameters.
A review of the crystallography and crystal chemistry of compounds in the BaO-CuOxsystem
Authors: Wong-Ng Winnie , Cook Lawrence P.
Published: January 2013

Literature data pertaining to the crystal chemistry, crystallography, and X-ray powder-diffraction properties of phases reported in the system BaO-CuOxare compiled. Reported phases include BaCuO2−2.12, BaCuO2.26−2.39, BaCuO2.5, Ba2CuO3+x, Ba2Cu3O5+x, BaCu2O2+x, Ba3Cu5O8, Ba3CuO4, BaCu3O4, Ba3Cu2O4+x, Ba5Cu3O6+x, and BaCu2O3. The existence of some of these phases, however, still has to be verified. Most of these compounds are nonstoichiometric in oxygen. Their oxygen content, and in some cases even their crystal structures, vary with oxygen partial pressure. There are also reported indications that the cations Ba and Cu are not stoichiometric in the cubic BaCuO2-type compounds.
Crystal data for [Cu(LIII)XY]·nH2O compounds [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1]
Authors: Arriortua M. I. , Insausti M. , Cortès R. , Larramendi J. I. R.
Published: January 2013

Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl–2-pyridyl–methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2′;6′,2″-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.
X-ray powder data for Nd2Co14B, Pr2Co14B and Pr2Fe14B
Authors: Wims A. M. , Fuerst C. D.
Published: January 2013

The crystal structure data have been determined by X-ray diffraction for three rare earth magnetic materials, Nd2Co14B, Pr2Co14B, and Pr2Fe14B. The data were evaluated with several computer programs desingned for that purpose. The crystal structure for Nd2Co14B and Pr2Fe14D determined by X-ray diffraction agree with those obtained earlier by neutron diffraction.
Quantitative phase analysis of α-Fe impurity in Ce2Fe17 matrix from neutron powder diffraction data
Authors: Yusuf Sk. Mohammad
Published: January 2013

The multicomponent Rietveld profile refinement technique for powder neutron diffraction patterns has been applied to arrive at a quantitative phase analysis of crystalline Ce2Fe17 and α-Fe impurity in a powder specimen of Ce2Fe17.
X-ray powder diffraction data for some transition metal phosphites and hypophosphites
Authors: Marcos M. Dolores , Amorós Pedro , Beltrán Daniel , Beltrán Aurelio
Published: January 2013

A set of nine transition metal oxophosphorous compounds, consisting of four hypophosphites and five phosphites has been synthesized and studied using X-ray powder diffraction techniques. The compounds are α-Mn(H2PO2)2·H2O, Co(H2PO2)2 ·0.53H2O, MCl(H2PO2)2·H2O (M = Co2+, Ni2+), M2(HPO3)2·2H2O (M = Co2+, Ni2+), and M11 (HPO3)8(OH)6 (M = Zn2+, Co2+, Ni2+). Unit cells and X-ray powder patterns are reported.
Anomalous peaks in grazing incidence thin film X-ray diffraction
Authors: Vaia Richard A. , Weathers Maura S. , Bassett William A.
Published: January 2013

Numerous spurious X-ray peaks were encountered during grazing incidence angle diffractometer scans of ceramic and polymeric thin films on crystalline and amorphous substrate materials. At least three possible sources of spurious peaks are identified. (1) At (2θ) values greater than ∼ 10°, Laue reflections from characteristic and Bremsstrahlung continuum radiation produce spurious peaks with a (2θ) dependence on X-ray incident angle and sample orientation. At (2θ) values less than 10°, (2) specular X-ray reflection from a boundary between two media of different indices of refraction and (3) diffuse surface scattering produces spurious peaks with a dependence on X-ray incident angle and sample surface topography. From an understanding of the spurious peaks, improved experimental techniques may be developed. Because these peaks can interfere significantly with grazing incidence diffractometer scans, it is particularly important to those making studies of thin films by this asymmetric diffraction geometry to be aware of the existence and origins of these spurious peaks.
Powder X-ray diffraction data for Ba4ZnTi11O27 and Ba2ZnTi5O13
Authors: Lindsay C. G. , Rawn C. J. , Roth R. S.
Published: January 2013

Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and studied using single-crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated from a least-squares refinement with a final maximum Δ2θ of 0.05°. Both phases were found to have monoclinic cells, space group C2/m. The refined lattice parameters for the Ba4ZnTi11O27 compound are a= 19.8687(8) Å, b=11.4674(5) Å, c=9.9184(4) Å, β= 109.223(4)°, and Z=4. The refined lattice parameters for the Ba2ZnTi5O13 compound are a= 15.2822(7) Å, b=3.8977(1) Å, c=9.1398(3) Å, β=98.769(4)°, and Z=2.
High phenotypic variation of seed traits, germination characteristics and genetic diversity of an invasive annual weed
Authors: Hantsch Lydia , Bruelheide Helge , Erfmeier Alexandra
Published: January 2013

Both phenotypic and genetic variation can affect the establishment success of exotic species. Using the weed Senecio vernalis Waldst. & Kit. with a continuous westward expansion of the native geographic range, we asked to what degree seed traits and germination patterns differ among different habitat disturbance types in the introduced region. We hypothesized that seed traits and germination pattern differ between different disturbance types, with lighter seeds and enhanced germination speed in highly disturbed habitats. Since S. vernalis colonizes successfully various disturbed habitats, we expected to find a high phenotypic genetic variation. Individuals from 19 populations were sampled from one region in Eastern Germany to study seed trait variation and germination success by means of a germination experiment and to assess genetic patterns using amplified fragment length polymorphism (AFLP) markers. Contrary to our expectation, habitat disturbance types did not differ in seed traits, germination characteristics or genetic variation. Instead, we found highest phenotypic and genetic variation within populations. Maximum percentage of germination was positively affected by seed mass. In addition, there was a weak but significant association between AFLP band patterns and population size and seed width, indicating that some variation in seed traits has a genetic component. In conclusion, the absence of a population differentiation at this geographic scale makes it unlikely that adaptation to different disturbance regimes is involved. Instead, a high variation in seed traits, overall high germination and genetic variation within populations under a wide range of habitat disturbance conditions seems to enable the offspring to colonize various habitat disturbance types.
Termination of hull-imposed dormancy in developing barley grains is correlated with changes in embryonic ABA levels and sensitivity
Authors: Benech-Arnold Roberto L. , Cristina Giallorenzi M. , Frank Julieta , Rodriguez Verónica
Published: January 2013

We studied changes in dormancy (as imposed by the different structures surrounding the embryo, namely, endosperm, pericarp and glumellae) and its relationship with changes in embryonic ABA levels and sensitivity, in developing grains of two commercial barley cultivars: B 1215 and Quilmes Palomar, which have, respectively, a low and high dormancy level at harvest and, consequently, a contrasting sprouting behaviour in rainy years. Dormancy imposed by endosperm plus pericarp was gradually and similarly alleviated throughout development in both cultivars. The presence of the hull (glumellae), in contrast, completely inhibited germination of grains from both cultivars until physiological maturity (PM). From there on, hull-imposed dormancy was removed abruptly in B 1215 grains, while in Q. Palomar ones, it was removed at a much lower rate. This difference determined the contrasting sprouting behaviour of these two cultivars within the ‘time window’ going from PM to crop harvest. Embryonic ABA content and sensitivity were similar in the two cultivars throughout development until PM. From there on, ABA content and sensitivity in B 1215 embryos declined dramatically coinciding with the abrupt termination of hull-imposed dormancy observed in this cultivar. In contrast, ABA levels in Q. Palomar embryos remained high for longer and sensitivity to ABA declined at a much slower rate. This correlation suggests that hull-imposed dormancy in barley might be regulated by embryonic ABA levels and / or sensitivity. Inhibition of GA synthesis with paclobutrazol applied after anthesis lowered the germination capacity of grains from both cultivars without altering that of the naked caryopses, thus further suggesting that hull-imposed dormancy is under hormonal control.
Medical oncologists' perception of palliative care programs and the impact of name change to supportive care on communication with patients during the referral process. A qualitative study
Authors: Rhondali Wadih , Burt Stephanie , Wittenberg-Lyles Elaine , Bruera Eduardo , Dalal Shalini
Published: January 2013

Objective:

In a simultaneous care model, patients have concurrent access to both cancer-directed therapies and palliative care. As oncologists play a critical role in determining the need/timing of referral to palliative care programs, their understanding of the service and ability to communicate this with patients is of paramount importance. Our study aimed to examine oncologists' perceptions of the supportive care program at M.D. Anderson Cancer Center, and to determine whether renaming “palliative care” to “supportive care” influenced communication regarding referrals.

Method:

This qualitative study used semi-directed interviews, and we analyzed data using grounded theory and qualitative methods.

Results:

We interviewed 17 oncologists. Supportive care was perceived as an important time-saving application, and symptom control, transitioning to end-of-life care, family counseling, and improving patients' ability to tolerate cancer therapies were cited as important functions. Although most claimed that early referrals to the service are preferable, oncologists identified several challenges, related to the timing and communication with patients regarding the referral, as well as with the supportive care team after the referral was made. Whereas oncologists stated that the name change had no impact on their referral patterns, the majority supported it, as they perceived their patients preferred it.

Significance of results:

Although the majority of oncologists favorably viewed supportive care, communication barriers were identified, which need further confirmation. Simultaneous care models that effectively incorporate palliative care with cancer treatments need further development.
Coral reef invertebrate microbiomes correlate with the presence of photosymbionts
Authors: Bourne David G , Dennis Paul G , Uthicke Sven , Soo Rochelle M , Tyson Gene W , Webster Nicole
Published: January 2013

Coral reefs provide habitat for an array of marine invertebrates that host symbiotic microbiomes. Photosynthetic symbionts including Symbiodinium dinoflagellates and diatoms potentially influence the diversity of their host-associated microbiomes by releasing carbon-containing photosynthates and other organic compounds that fuel microbial metabolism. Here we used 16S ribosomal RNA (rRNA) gene amplicon pyrosequencing to characterise the microbiomes of 11 common Great Barrier Reef marine invertebrate species that host photosynthetic symbionts and five taxa in which they are absent. The presence of photosynthetic symbionts influenced the composition but not the species richness, evenness and phylogenetic diversity of invertebrate-associated microbiomes. Invertebrates without photosynthetic symbionts were dominated by Alphaproteobacteria, whereas those hosting photosynthetic symbionts were dominated by Gammaproteobacteria. Interestingly, many microbial species from photosymbiont-bearing invertebrates, including Oceanospirillales spp., Alteromonas spp., Pseudomonas spp., Halomonas spp., are implicated in the metabolism of dimethylsulfoniopropionate (DMSP). DMSP is produced in high concentrations by photosynthetic dinoflagellates and is involved in climate regulation by facilitating cloud formation. Microbiomes correlated with host taxa and replicate individuals from most sampled species grouped in distance-based redundancy analysis of retrieved 16S rRNA gene sequences. This study highlights the complex nature of invertebrate holobionts and confirms the importance of photosynthetic symbionts in structuring marine invertebrate bacterial communities.
On characteristic formulae for Event-Recording Automata
Authors: Nguena Timo Omer Landry , Reynier Pierre-Alain
Published: January 2013

A standard bridge between automata theory and logic is provided by the notion of
characteristic formula. This paper investigates this problem for the class of
event-recording automata (ERA), a subclass of timed automata in which clocks are
associated with actions and that enjoys very good closure properties. We first study the
problem of expressing characteristic formulae for ERA in Event-Recording Logic (ERL ), a
logic introduced by Sorea to express event-based timed specifications. We prove that the
construction proposed by Sorea for ERA without invariants is incorrect. More generally, we
prove that timed bisimilarity cannot in general be expressed in ERL for the class of ERA ,
and study under which conditions on ERA it can be. Then, we introduce the logic
WTμ , a new logic for event-based timed specifications
closer to the timed logic ℒν that was introduced by
Laroussinie, Larsen and Weise. We prove that it is strictly more expressive than ERL , and
that its model-checking problem against ERA is EXPTIME -complete. Finally, we provide
characteristic formulae constructions in WTμ for
characterizing the general class of ERA up to timed (bi)similarity and study the
complexity issues.
Die Bedeutung von planen Aufbissschienen für die kieferorthopädische Diagnostik und Therapie
Authors: Harbo H. P. , Troest T.
Published: January 2013

Plane Aufbissschienen haben sich bei der Behandlung von kraniomandibulären Dysfunktionen und bei der Wiederherstellung der Okklusion bewährt. Dieser Artikel ist eine praktische Anleitung dazu, wie wertvoll eine ganztägige Schienentherapie – in ausgewählten Fällen bei Hinweisen auf eine Kiefergelenkbeteiligung – für die kieferorthopädische Diagnose und Therapie sein kann.
An apparatus for studying scintillator properties at high isostatic pressures
Authors: Gaumé R. M. , Lam S. , Gascón M. , Setyawan W. , Curtarolo S. , Feigelson R. S.
Published: January 2013

We describe the design and operation of a unique hydraulic press for the study of scintillator materials under isostatic pressure. This press, capable of developing a pressure of a gigapascal, consists of a large sample chamber pressurized by a two-stage hydraulic amplifier. The optical detection of the scintillation light emitted by the sample is performed, through a large aperture optical port, by a photodetector located outside the pressure vessel. In addition to providing essential pressure-dependent studies on the emission characteristics of radioluminescent materials, this apparatus is being developed to elucidate the mechanisms behind the recently observed dependency of light-yield nonproportionality on electronic band structure. The variation of the light output of a Tl:CsI crystal under 511-keV gamma excitation and hydrostatic pressure is given as an example.
Magnetostructural coupling near room temperature in Ni46-xFexCu4Mn34Ga16 alloys
Authors: Wang Jingmin , He Yangkun , Jiang Chengbao
Published: January 2013

We report the magnetostructural coupling near room temperature in Ni46-xFexCu4Mn34Ga16 (0 ≤ x ≤ 10) alloys. The martensitic transformation temperature was detected over the whole composition range and was decreased by the substitution of Fe for Ni. The martensitic and austenitic Curie temperatures, TCM and TCA, were observed for 0 ≤ x ≤ 6 and 4 ≤ x ≤ 10, respectively. With the increasing Fe content, TCA was slightly increased and TCM was more rapidly increased. The paramagnetic state of the martensite phase collapsed for x > 6 with the presence of the ferromagnetic austenite phase. The magnetostructural coupling transition from paramagnetic martensite to ferromagnetic austenite was obtained within the temperature range of 300–350 K which was near room temperature.
Ultraviolet laser deposition of graphene thin films without catalytic layers
Authors: Sarath Kumar S. R. , Alshareef H. N.
Published: January 2013

In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.
Effect of hydrostatic pressure on magnetic entropy change and critical behavior of the perovskite manganite La0.4Bi0.3Sr0.3MnO3
Authors: Thiyagarajan R. , Esakki Muthu S. , Barik S. K. , Mahendiran R. , Arumugam S.
Published: January 2013

We report the effect of magnetic field (H) and hydrostatic pressure (P) on the order of magnetic transition of polycrystalline La0.4Bi0.3Sr0.3MnO3 which undergoes a first-order paramagnetic (PM) to ferromagnetic (FM) transition in La0.7−xBixSr0.3MnO3 series. The ferromagnetic Curie temperature (TC) increases with increasing H (12.01 K/T-cooling and 10.28 K/T-warming) and P (8.1 K/kbar-cooling and 6 K/kbar-warming). The first-order FM transition becomes second-order under the applied magnetic field of 9 T and pressure of 9.1 kbar. We have analyzed the critical behavior associated with the second order PM-FM transition at 9.1 kbar. The estimated critical exponents (β = 0.5217, γ = 1.209, and δ = 3.162) are found to be close to the mean-field model. Pressure suppresses metamagnetic transition in magnetization isotherms observed above TC in ambient pressure and enhances the magnetic entropy change (ΔSm). The ΔSm was found to increase by 50% under hydrostatic pressure of 9.1 kbar at TC = 240 K. This study suggested that hydrostatic pressure can be used to enhance magnetocaloric values in phase separated manganites.
Emission characteristics in solution-processed asymmetric white alternating current field-induced polymer electroluminescent devices
Authors: Chen Yonghua , Xia Yingdong , Smith Gregory M. , Gu Yu , Yang Chuluo , Carroll David L.
Published: January 2013

In this work, the emission characteristics of a blue fluorophor poly(9, 9-dioctylfluorene) (PFO) combined with a red emitting dye: Bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate)iridium (III) [Ir(MDQ)2(acac)], are examined in two different asymmetric white alternating current field-induced polymer electroluminescent (FIPEL) device structures. The first is a top-contact device in which the triplet transfer is observed resulting in the concentration-dependence of the emission similar to the standard organic light-emitting diode (OLED) structure. The second is a bottom-contact device which, however, exhibits concentration-independence of emission. Specifically, both dye emission and polymer emission are found for the concentrations as high as 10% by weight of the dye in the emitter. We attribute this to the significant different carrier injection characteristics of the two FIPEL devices. Our results suggest a simple and easy way to realize high-quality white emission.