bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystals of rare‐earth‐ferrous borates
Authors: Maltseva L. I. , Leonyuk N. I. , Timchenko T. I. 
Published: July 2007

AbstractCrystals of rare‐earth‐ferrous borates (structure of carbonate mineral huntite, space group R 32) were obtained from the solution‐melt with the Bi2O3‐B2O3 base. It was established by the methods of X‐ray structural and chemical analyses that large amounts of Bi from the solution became part of the crystals affecting their solubility, morphology and hardness. Solubility curves for YFe‐, NdFe‐, and ErFe‐borates in the 3 Bi2O3 5 B2O3 melt were plotted. Refinement of crystalline structure of NdFe‐borate showed that bismuth takes up place of rare‐earth ion in the crystal lattice. Parameters of unit cells, density and refractive indexes of the obtained crystals were measured.
The crystallisation of alkaline‐earth metal silicates and titanates from metal chloride melts solubility‐temperatur phase diagram studies
Authors: Packter A. 
Published: July 2007

AbstractThe solubility‐temperature phase diagrams have been analysed for calcium and barium silicate solutions and for calcium, strontium and barium titanate solutions in the metal chloride melts. These systems are typical binary metal salt mixtures with no solid solution or compound formation. Activity coefficients were estimated from log solubility v reciprocal temperature plots and the anion polymerisation numbers were estimated from these coefficients. The metal silicate systems are non‐ideal at silicate mole fractions from 0.1 to 0.8: the solubilities at any temperature are appreciably greater than the ideal values determined from the temperatures and enthalpies of metal silicate fusion: the calcium silicate systems contain upto 50 percent trisilicate chains, while the barium silicate systems contain up to 100 percent trisilicate chains and significant amounts of tetrasilicate chains. The metal titanate systems are practically ideal at titanate mole fractions from 0.01 to 0.3 and possibly upt < 0.6; the solubilities at any temperature are then determined by the temperatures and enthalpies of metal titanate fusion, only.
The X‐ray method for the determination of damaged layer thickness of the Si crystal surface
Authors: Auleytner J. , Bak J. , Furmanik Z. , Maciaszek M. , Saulewicz A. 
Published: July 2007

AbstractIn this paper the X‐ray section topograph method was used for determination of damaged layer thickness of silicon crystal surface. For measurements such reflections should be chosen for which the “margine” effect is very sharp. It was used the fact that in the ranges of strong perturbances the approximation of kinematic theory could be applied.
Coloration, photoconductivity, photo‐ and thermoluminescence of PbMoO4 crystals
Authors: Bollmann W. 
Published: July 2007

AbstractAn absorption band at 435 nm with a half‐value width of 0.57 eV which causes the yellowish colour of PbMoO4 crystals is due to Pb3+ ions. Pb3+ ions are produced by oxidation of the crystals or by incorporation of foreign cations of oxidation state lower than 6 at Mo5+ sites. Usual Pb3+ ion mole fractions are ⪅ 10−7. Annealing of the crystals at low oxygen partial pressure discolours them. Colourless crystals become coloured at low temperatures by ionizating irradiation causing absorption bands at 380 and 575 nm due to Mo5+ ions and at about 990 nm due to an other electronic centre (may be Pb+ or F centre). Heating causes a thermoluminescence connected with disoloration which is finished at room temperature.
Dislocation etching in V3Si
Authors: Gohar I. A. , Kleinstück K. , Krämer U. , Paufler P. 
Published: July 2007

AbstractDislocations in as‐grown and in plastically deformed V3Si single crystals have been studied by chemical etching. In as‐grown crystals dislocations are partly arranged in small‐angle boundaries parallel to {001}, {011}, and {112} planes. The total dislocation density amounted to (105−106) cm−2. After plastic deformation at elevated temperatures indications for slip and climb processes were observed. The dislocation density increased to 107 cm−2.
On the reproducibility of the orientation distribution function of texture samples from pole figures (II). Consequences of the limited reproducibility of the ODF — ghost phenomena
Authors: Matthies S. 
Published: July 2007

AbstractBy means of illustrative examples the appearance of ghost phenomena in orientation distribution functions derived by standard methods from pole figure datas is demonstrated in a qualitative manner. It is shown, that as a rule ghost phenomena have no influence on the results of calculations of macroscopic properties of textured samples.
Propagation of acoustic waves in crystals of univalent mercury halides
Authors: Barta Č. , Silvestrova P. M. , Moiseeva N. A. , Pisarevskij J. U. V. 
Published: July 2007

AbstractSections through the surfaces of phase and group velocities of propagation of acoustic waves in Hg2Cl2, Hg2Br2 and Hg2I2 were ascertained. The relations between the directions of energy propagation and the directions of phase velocities were also established. It was found that the energy flux deviates from the A‐plane towards the [001] direction. The direction of the smallest velocity of propagation of acoustic waves in the A‐plane was found, too. The results of this study are interesting especially with respect to the practical utilization of some new types of acoustic and acousto‐optic elements.
The crystallization mechanism in high strength glass‐ceramics
Authors: Doenitz F.‐D. , Vogel W. 
Published: July 2007

AbstractThe addition of NiO to a MgOAl2Al2O3SiO2 basic glass has an influence on the phase separation and crystallization mechanism. The differentiation of the components already detectable in the amorphous state continues in the crystallization process of the nickel‐rich glasses. The formation of NiAl‐spinel in the bulk restricts the precipitation of high quartz crystals to the skin. The result is a high strength glass‐ceramic with clearly distinguishable bulk and surface regions.
Random motion of IV‐dipoles in alkali halide crystals forming stable aggregates
Authors: Berg G. , Schmidt R. , Fröhlich F. 
Published: July 2007

AbstractThe formation of higher aggregates of IV‐dipoles consisting of a divalent impurity ion and a cation vacancy is investigated by the simulation of their random motion in a model lattice at different annealing temperatures. An interaction potential between the sink for the dipoles and the dipole in the lattice is assumed. Additionally a decay of the sink is allowed. The results show, that already two dipoles (i.e. a dimer) from a stable aggregate. This is in agreement with theoretical calculations of the equilibrium concentrations of higher aggregates and the results of kinetic measurements of dipole aggregation. The reason is the relative high binding energy of dipoles in alkali halide crystals.
Double crystal diffractometry for the characterization of targets for laser fusion experiments
Authors: Förster E. , Goetz K. , Zaumseil P. 
Published: July 2007

AbstractThe application of a double‐crystal diffractometer for the production of X‐ray Schlieren topographs is described. The experimental arrangement is optimized on the basis of a wave‐optical description for the investigation of shell targets for laser fusion experiments. The accuracies achieved at the wall thickness measurement of 0.01 … 0.1 μm depending on the series of wall materials and the effort of evaluation fulfil the plasma physical requirements. This opens an important new field of application for the double‐crystal diffractometer.
Structure perfection of some molecular crystals grown from the melt
Authors: Naumowicz P. , Szarras S. 
Published: July 2007

AbstractSingle crystals of anthracene, naphthalene, phenazine and anthracene sym. trinitrobenzene (TNB) were examined using X‐ray topography. Low‐angle boundaries were observed and misorientation vectors of adjacent mosaic blocks have been estimated. Using an X‐ray camera with oscillating film dislocation density in crystals has been evaluated. Anthracene‐TNB crystals showed a much higher structure perfection than the other crystals.
Investigations for Sn diffusion in Pb1−xSnxTe and PbTe
Authors: Siche D. , Ermisch W. 
Published: July 2007

AbstractBy annealing Pb1−xSnxTe and PbTe isothermally in a quartz ampoule Sn diffused from Pb1−xSnxTe into PbTe. The profiles obtained have been investigated by means of an electron beam microanalyser, and the coefficients of diffusion have been determined at various temperatures. The diffusion of Sn can be explained by the expressions: DPbSnTe = 1.5 · 10−1 exp (−1.8 eV/kT) cm2 s−1 (0,14 < x < 0,18) DPbTe = 5,5 · 10−4 exp (−1.5 eV/kT) cm2 s−1.N‐type layers are observed at the surface of Pb1−xSnxTe specimens.
A linear relativistic method for the calculation of band structure in transition metals with results for Au
Authors: Ziesche P. , Wonn H. , Fleck U. 
Published: July 2007

AbstractWith a linear relativistic method we calculated the band structure of gold. A comparison with the results of a RAPW calculation shows that the deviation is about 3%. The effort of computational time is for the linear method considerably smaller than for the RAPW method.
On the quaternary NGa‐NAl‐NAs‐NGe phase diagram
Authors: Geselle B. , Herrmann F. P. , Wagner G. 
Published: July 2007

AbstractIt was stated that the thickness of Ge‐doped GaAs‐ and AlxGa1−xAs epitaxial layers, respectively, grown by equilibrium cooling from a gallium rich flux, varies with the Ge concentration in the liquid phase. This relationship was applied to calculate an quaternary Ga‐Al‐As‐Ge phase diagram by means of the law of mass action.
Influence of stacking disorder on the electronic properties of layered semiconductors
Authors: Maschke K. 
Published: July 2007

AbstractIt is shown that stacking disorder in layered semiconductors leads to a localization of the electronic wavefunctions over a finite number of layers. The electronic transport across the layers is described in terms of a hopping model. The experimentally observed strong anisotropy of the de‐conductivity for low temperatures is explained as a consequence of the stacking disorder.
X‐ray heating chamber investigations of reforming Pt‐Al2O3 catalysts
Authors: Richter K. , Bornmann P. 
Published: July 2007

AbstractModel catalysts with increased Pt content and commercial catalysts have been tested in an X‐ray heating chamber at different temperatures and in various fluids (O2, N2, N2/H2 and Ar) at atmospheric pressure. In an air atmosphere and at temperatures between ambient and approx. 850 K, the Pt crystallites are subjected to superficial oxidation, sintering starts at approx. 850 K. In a hydrogen atmosphere, an increase in temperature at first results in the formation of crystalline Pt particles having a degree of crystallinity of 100% (error range 5%). Depending on the kind of sample and beginning at approx. 700 K, a Pt hydride phase which is stable in H2 only and has a lattice constant of a = 3.875 Å is formed later on.Furthermore, conclusions for the evaluation and interpretation of X‐ray measurements of catalysts are drawn.
Domain structure in main crystallographic planes of orthoferrites at spin reorientation
Authors: Ges' A. P. , Fedotova V. V. 
Published: July 2007

AbstractThe behaviour peculiarities of the domain structure of the single crystal samarium‐terbium‐erbium and samarium‐terbium‐thulium orthoferrites in the spin reorientation range in three crystallographic planes (001), (110) and (100) are investigated. In the (001)‐plane the temperature‐induced bubble domain lattice formation is observed. The formation kinetics of these domains is similar to the process of nucleation and that of growth with spontaneous crystallization. In the (110) plane the inclined domains formation is noted. The canting angle depends on temperature at spin reorientation. The values of remagnetization fields are measured as a function of temperature in the indicated crystallographic planes. From the measured changes of the domain structure the temperature dependences of the first anisotropy constant and the domain wall density are determined.
A Study of Electrical Conductivity in Concentrated Solid Solutions ca1−xLnxF2+x (Ln = La, Gd, Er, Y)
Authors: Švantner M. , Mariani E. , Fedorov P. P. , Sobolev B. P. 
Published: July 2007

AbstractThis work completes our previous results on the measurement of electrical conductivity in fluorite solid solutions Ca1‐xLnxF2+x (MARIANI et al.), ŠVANTNER et al.) and gives new results for Ca1‐xGdxF2+x and Ca1‐xErxF2+x. The main characteristic of the measured ln σ vs 1/T dependences in an increase of electrical conductivity and decreases of activation energy with increasing concentration of LnF3. The preexponential terms in the Arrhenius formula for electrical conductivity are constant for x > 0.01. In the interpretation of measured results the existence of regions with high concentration of defects is assumed in agreement with structural views.
On crystal chemistry and morphology of extended organic molecules
Authors: Follner H. 
Published: July 2007

AbstractThe present paper is concerned with the morphology and crystal structure of extended organic compounds in the space group P 21/c. In the structures with molecules in general position (Z = 4) the longitudinal axis of all molecules run parallel to a (h0l)‐plane. The molecule arrangements are based on four different structure types. The planes through the molecule axis contain a) 21‐axis and symmetry centres (l = 2n), b) 21‐axis or symmetry centres (l = 2n + 1) and c) respectively d) no symmetry element (l = 2n resp. 2n + 1). In the last two cases the net plane distances are to be halved. As in P 21/c the a‐und c‐axis are not set, one can confine oneself to the examination of the net planes (102), (202), (204), and (404). In the cases of a) and b), only certain morphological lattices appear, which distinguish themselves through additional translations in three‐dimensional space resp. in the projections. In the cases of c) and d) there are also found morphological lattices which generate additional “morphological extinctions” (consequently possessing a higher symmetry than the generating space group), but which contain no translationally higher symmetry. (h0l)‐faces, to which the molecule axis run parallel, appear with preference on crystals. As a rule the first two and the last two cases can be differentiated on account of the position of the (h0l)‐faces in the Donnay‐Harker series. Some examples will show that the morphological lattice can be preserved through Fourier transformation of crystal morphology.
Solution‐mediated polymorphic transformation of stearic acid
Authors: Wellner E. , Garti N. , Sarig S. 
Published: July 2007

AbstractPolymorphic transformations of stearic acid in their crystallization solutions have been studied. When stearic acid crystals were left in the ethanolic saturated mother liquor, the B‐form modification was obtained throughout the whole process. In n‐hexane and benzene during the first 2–3 hours, the C‐polymorph was the predominant form, later transformed progressively into the B‐form, so that towards the end of the experiment the whole precipitate was in the B‐form. The proposed explanation is that the transformation is due to dissolution caused by thermal fluctuation in the bath, and subsequent precipitation. The dissolution and reprecipitation was followed up by micro photographs. In the presence of Span 60, only C form was obtained in all the solvents. – As a result of this study it is suggested to pay attention to possible solution‐mediated polymorphic transformations of the crystallized material which may cause a misleading interpretation of the factors affecting the crystallization of the fatty acid.
Impurity States in CuInSe2
Authors: Neumann H. , Nowak E. , Kühn G. 
Published: July 2007

AbstractThe impurity states occurring in CuInSe2 crystals after annealing in an atmosphere of Se and in‐diffusion of In are determined by electrical measurements. The experimental results suggest the conclusion that the shallow donor with an ionization energy of about 10 meV is due to Se vacancies, the shallow acceptor with about 35 meV due to In vacancies, and the acceptor with about 100 meV due to Se interstitials. The deep acceptor with an ionization energy of about 400 meV is assumed to be due to Fe2+ substituted on In sites.
A comparative arima analysis of the 111 series of the makridakis competition
Authors: Lusk Edward J. , Neves Joao S. 
Published: July 2007

AbstractThe 111 series of the Makridakis competition are used to address a number of questions pertaining to use of the Box–Jenkins technique. The ARIMA models developed are compared to the ARIMA models developed independently by Andersen for the Makridakis competition. The time required to perform the analysis for each series is discussed in terms of model complexity. Forecast accuracy, measured as the MAPE for the one step ahead forecast, is discussed for different series lengths.
Conditional distribution analyses of probabilistic forecasts
Authors: Yates J. Frank , Curley Shawn P. 
Published: July 2007

AbstractProbabilistic forecasts have good ‘external correspondence’ if events that are assigned probabilities close to 1 tend to occur frequently, whereas those assigned probabilities near 0 tend to occur rarely. This paper describes simple procedures for analysing external correspondence into meaningful components that might guide efforts to understand and improve forecasting performance. The procedures focus on differences between the judgements made by the forecaster when the target event occurs, as compared to when it does not. The illustrations involve a professional oddsmaker's predictions of baseball game outcomes, meteorologists' precipitation forecasts and physicians' diagnoses of pneumonia. The illustrations demonstrate the ability of the procedures to highlight important forecasting tendencies that are sometimes more difficult to discern by other means.
Regression forecasts when disturbances are autocorrelated
Authors: Dielman Terry E. 
Published: July 2007

AbstractA Monte Carlo simulation is used to study the quality of forecasts obtained from regression models with various degrees of autocorrelation present in the disturbances. The methods used to estimate the model parameters include least squares, full maximum likelihood, Prais‐Winsten, Cochrane‐Orcutt and Bayesian estimation. Results indicate that the Cochrane‐Orcutt method should be avoided. The full maximum likelihood, Prais‐Winsten and Bayesian methods are relatively more efficient than least squares when the degree of autocorrelation is high (greater than or equal to 0.5) and show little efficiency loss when the degree is low. These results hold for both trended and untrended independent variables.
Forecasting contemporaneous aggregates and the combination of forecasts: The case of the U.K. monetary aggregates
Authors: Mills Terence C. , Stephenson Michael J. 
Published: July 2007

AbstractA number of papers in recent years have investigated the problems of forecasting contemporaneously aggregated time series and of combining alternative forecasts of a time series. This paper considers the integration of both approaches within the example of assessing the forecasting performance of models for two of the U.K. monetary aggregates, £M3 and MO. It is found that forecasts from a time series model for aggregate £M3 are superior to aggregated forecasts from individual models fitted to either the components or counterparts of £M3 and that an even better forecast is obtained by forming a linear combination of the three alternatives. For MO, however, aggregated forecasts from its components prove superior to either the forecast from the aggregate itself or from a linear combination of the two.
Experience in combining subjective and quantitative forecasts of open market rates
Authors: de Bragança Pereira Basilio , Coqueiro Ricardo Cesar Otero , Perrota Antonio Horácio Vincente 
Published: July 2007

AbstractThis paper presents a method of combining subjective information from open‐market operators with results from a time‐series forecasting model. Empirical results of forecasts for interest rates of bank reserves are presented.
Judgmental adjustment of earnings forecasts
Authors: Wolfe C. , Flores B. 
Published: July 2007

AbstractEarnings forecasts have received a great deal of attention, much of which has centered on the comparative accuracy of judgmental and objective forecasting methods. Recently, studies have focused on the use of combinations of subjective and objective forecasts to improve forecast accuracy. This research offers an extension on this theme by subjectively modifying an objective forecast. Specifically, ARIMA forecasts are judgmentally adjusted by analysts using a structured approach based on Saaty's (1980) analytic hierarchy process. The results show that the accuracy of the unadjusted objective forecasts can be improved when judgmentally adjusted.
Forecasting market potential and market penetration of residential water heater load control programs
Authors: Wood Lisa L. , Mauskopf Josephine A. 
Published: July 2007

AbstractThis paper presents a model which estimates market potential and forecasts market penetration for one demand‐side management (DSM) programwater heater load controlin the service territory of Virginia Power Corporation, a large electric utility in the south‐eastern United States. Water heater load control is a voluntary program where customers are paid a monthly incentive to allow the utility to shut off power to their electric water heaters during periods of peak demand. Reducing the level of peak demand through DSM programs is one way for utilities to avoid building new power plants. The current total energy (or demand) impact due to a load control program is the sum of the changes in energy (or demand) for all program participants. The projected energy and demand impact due to a load control program is the average change per participant multiplied by the number of participants or adopters of the program. While it is reasonably straightforward to measure the energy savings resulting from shutting off power to a water heater, the more difficult task for planning purposes is forecasting the number of customers who will actually join the program (i.e. the market penetration) for a given incentive. The customer decision process is divided into three stages: eligibility, awareness, and adoption. The responsiveness of market penetration to changes in advertising and incentive amounts is demonstrated. In addition, the impact of changing advertising and incentive amounts on the percentage of aware customers who adopt the program and on that of eligible customers who become aware of the program is estimated. This model can be used by utility planners and managers to forecast the market penetration of both new and existing load control programs. In addition, it can be employed to estimate the impact of various promotion and marketing schemes on both market potential and market penetration.
Criterion‐referenced judgemental forecasting models
Authors: Remus William E. 
Published: July 2007

AbstractHuman judgements are usually made with reference to a criteria such as cost or profit. When making a judgement model for such a decision, the ideal is for the model to yield near‐optimal results in terms of the criteria. This article starts with the theory behind concave criteria and then develops a mathematical argument which gives guidance to judgemental model building. This guidance departs from the conventional wisdom of using only R‐squared in model selection.