bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-frequency Raman Spectroscopy of Aqueous Solutions of Aliphatic Alcohols
Authors: Ydoshida Koji , Yamaguchi Toshio 
Published: February 2015

Abstract
Low-frequency Raman spectra have been measured at room temperature as functions of the alcohol mole fraction in aqueous solutions of methanol, ethanol, 1-propanol, 2 -propanol, and /er/-butylalcohol (TBA). Intrinsic Raman spectra R (ῡ) were obtained from depolarized Rayleigh wing spectra. Isosbestic points have been observed in R (ῡ) of the aqueous solutions of ethanol, 1-propanol, and 2 -propanol, suggesting that the structure o f the solutions is characterized by individual alcohol aggregates and water clusters without a significant amount of alcohol-water mixed aggregates. The R (ῡ) spectra have been expressed as R (ῡ ,x ) = w R (ῡ ,0 ) + aR(D, 1), where R(ῡ, 0) and R(ῡ, 1) are those for pure water and pure alcohols, respectively, and x is the mole fraction of alcohols. The coefficients w and a show the inflection points at characteristic alcohol mole fractions, where microhetrogeneity and structural transition of the solvent clusters take place, as previously shown by X-ray diffraction. In the aqueous solutions of methanol, where no microhetrogeneity takes place, no clear isosbestic point in R(ῡ) has been observed. For aqueous solutions of TBA, an isosbestic point in R(ῡ) has appeared when xTBA > 0.05. Two inflections points in the coefficients have been observed at xTBA « 0.1 and 0.35; the former composition corresponds to the transition composition from the TBA-TBA intermolecular contact to the TBA water molecular association, as previously reported by neutron diffraction.
Nuclear Spin Relaxation and Water Self-diffusion in Hardening Magnesium Oxychloride Cement
Authors: Nestle Nikolaus , Galvosas Petrik , Zimmermann Christian , Dakkouri Marwan , Kärger Jörg 
Published: February 2015

Abstract
In this contribution, we report the results of NMR studies of the behaviour of water in a hydrating Sorel cement paste with a composition close to the stoichiometric optimum. Both the transverse spin-relaxation behaviour and water self-diffusion were studied in two separate experiments performed on samples on the basis of the same formulation. While there is a very strong initial decrease in the transverse relaxation time of the water in the paste, the diffusion coefficient is found to decrease mainly at later times of the hydration process where the decrease of the transverse relaxation time has already strongly slowed down. After about 6 h of the hardening process, the signal intensity available for a pulsed gradient diffusometry experiment is not sufficient any more for reliable measurements of the diffusion coefficients
Energy Eigenvalue Level Motion with Two Parameters
Authors: Steeb Willi-Hans , Hardy Yorick , Stoop Ruedi 
Published: February 2015

Abstract
From the eigenvalue equation Ĥλ|(ψn)〉 = En(λ)|ψn(λ)〉 where Ĥ0 = Ĥ0 + XV̂ one can derive an autonomous system of first order ordinary differential equations for the eigenvalues En(λ) and the matrix elements Vmn(λ) := 〈ψm|V̂|ψn(λ)〉 where λ is the independent variable. We derive the partial differential equations for the extended case Ĥλ1λ2= Ĥ0 + λ1V̂1 + X2V̂2, where λ1 and λ2 are the independent variables. Some applications of this system of partial differential equations are discussed.
Dielectric Permittivity and AC Conductivity Investigation for the New Model Lipid Bilayer Material: (CH2)10(NH3)2CdCl4
Authors: Mostafa Mohga F. , Youssef Ahmed A. A. 
Published: February 2015

Abstract
Differential thermal scanning of the new lipid-like bilayer material (CH2)10(NH3)2CdCl4 showed two structural phase transitions, with onset temperatures at T2 = (359 ± 2) K and T1 = (415± 1) K. Permittiv­ity measurements were performed between room temperature and 450 K at 60-100 kHz. A step-like rise in permittivity at T2, associated with an order-disorder transition, is attributed to chain melting. Two anomalies at (413 ± 1) K and (430 ± 3) K, showing thermal hysteresis of -8 and 10 K, respectively, in­ dicate first order transitions which are associated with crystalline phase change. The AC conductivity follows an Arrhenius-type relation with the activation energy ΔE varying with the frequency / according to the relation ΔE = ΔE0 [1 -exp (f0/f)] where ΔE0,f0 and a are 0.95 eV, 52 Hz and 0.11, respectively. The frequency dependent conductivity follows the power law σ= σdc +Bωx with 0.3 <s< 1.5 for hopping conduction of hydrogen and/or chloride ions in the high temperature range, and localized hopping and/or orientational motion predominating temperatures lower than 413 K. Variations of B and s with temperature are discussed. PACS No. 76, 77
Dielectric Relaxation of Three Ethanolamines
Authors: Wichmann M. , Stockhausen M. 
Published: February 2015

Abstract
Relaxation spectra have been measured at 20°C for mono-, di-and triethanolamine in the pure liquid state and in a 0.6 mole fraction mixture with 1,4-dioxane. The general resemblance to the dielectric behaviour of alcohols and aminoalcohols shows that relaxation is governed by association effects. In this regard, several features point to significantly differing behaviour of the mono compound in comparison with both di-and triethanol­ amine.
Thermodynamics and Structure of Liquid Metals from a New Consistent Optimized Random Phase Approximation
Authors: Badirkhan Z. , Pastoreb G. , Akinlade O. 
Published: February 2015

Abstract
We study thermodynamics and structural properties of several liquid metals to assess the validity of the generalized non-local model potential (GNMP) of Li et al. [J. Phys. F16, 309 (1986)].
By using a new thermodynamically consistent version of the optimized random phase approx­ imation (ORPA), especially adapted to continuous reference potentials, we improve our previous results obtained within the variational approach based on the Gibbs -Bogoliubov inequality.
Hinging on the unified and very accurate evaluation of structure factors and thermodynamic quantities provided by the ORPA, we find that the GNMP yields satisfactory results for the alkali metals. Those for the polyvalent metals, however, point to a substantial inadequacy of the GNMP for high valence systems.
A New Generalization of the (2+1)-dimensional Davey-Stewartson Equation
Authors: Lin Ji , Tang Xiao-yan , Lou Sen-yue , Wang Ke-lin 
Published: February 2015

Abstract
Using an asymptotically exact reduction method based on Fourier expansion and spatiotemporal re-scaling, a new integrable system of the nonlinear partial differential equation in (2+1)-dimensions, extended Davey-Stewartson I equation, is deduced from a known (2+1)-dimensional integrable equation. The integrability of the new equation system is explicitly proved by the spectral transformation. Actually, the corresponding Lax pair of the new equations can be obtained by applying the same reduction method to the Lax pair of the original equation.
Abundant Coherent Structures of the (2+1)-dimensional Broer-Kaup-Kupershmidt Equation
Authors: Ying Jin-ping , Lou Sen-yue 
Published: February 2015

Abstract
By using of the Bäcklund transformation, which is related to the standard truncated Painleve analysis, some types of significant exact soliton solutions of the (2+1)-dimensional Broer-Kaup-Kupershmidt equation are obtained. A special type of soliton solutions may be described by means of the variable coefficient heat conduction equation. Due to the entrance of infinitely many arbitrary functions in the general expressions of the soliton solution the solitons of the (2+1)- dimensional Broer-Kaup equation possess very abundant structures. By fixing the arbitrary functions appropriately, we may obtain some types of multiple straight line solitons, multiple curved line solitons, dromions, ring solitons and etc.
pVT Measurements and Related Studies on the Binary System nC16H34 -nC17H36 and on nC18H38 at High Pressures
Authors: Würflinger Albert , Mondieig Denise , Rajabalee Fazil , Cuevas-Diarte Miquel Angel 
Published: February 2015

Abstract
The phase diagram of the binary system nC16H34 -nC17H36 has been established at ambient pressure using DSC and crystallographic measurements. At low temperatures below the rotator phase RI there exist two crystal forms Op (about x(C17) = 0.25) and Mdci (about x(C17) = 0.67) which are different from the crystal structures of the pure compounds (Tp for C16 and Oi for C17). Furthermore two compositions: (a) C16/C17 = 3:1 and (b) = 1:2, which correspond to the coexistence range of Op and Mdci, were chosen for high pressure DTA and pVT measurements, yielding the following findings: The specific volume of the rotator phase of C17 is distinctly lower than those of the binary systems at the same state point. Assuming the existence of a metastable rotator phase for C16, an excess volume of Δ VE/V ≈ 0.01 can be estimated. Due to the very enlarged coexistence range of RI, the mixtures reach their lower transition point at considerably lower temperatures (in isobaric measurements) or higher pressures (in isothermal measurements), where the specific volume is lower than that of C17 at its transition point. Furthermore, the volume and enthalpy changes of the Φord -RI transition is distinctly smaller for the binary systems than for pure C17. Thus the specific volumes of the phases Op and Mdci are appreciably larger than ν(spec.) of C17. Op and Mdci have practically the same specific volume in accordance with the crystallographic results. Enthalpy values are obtained with the aid of the Clausius-Clapeyron equation which agree well with enthalpies derived from the DSC measurements.
Furthermore, pVT data have been established for the liquid and solid phases of nC18H38 in the neighbourhood of the melting curve, allowing to determine volume and enthalpy changes of melting as a function of pressure.
Isolated versus Condensed Anion Structure VII: X-ray Structure Analysis of 1,3-Propanediammonium Dibromodichlorocadmate(II), [H3N(CH2)3NH3]CdBr2Cl2, and Estimation of Stability of Five-coordinated Halide Anions, MX5
3-(M = Cd, Zn; X = Cl, Br) by Means of Ab-initio MO Calculations
Authors: Ishihara Hideta , Okajima Toshiya , Horiuchi Keizo , Svoboda Ingrid , Fuess Hartmut 
Published: February 2015

Abstract
The coordination capability of Cl and Br in halogenocadmate(II) complexes is estimated by a solution of the structure of 1,3-propanediammonium dibromodichlorocadmate(II). The compound crystallizes as a layered anion structure with Cl bridges and Br terminals at 293 K: Imma, a = 741.56(7), b = 1869.5(5), and c -771.55(8) pm, Z = 4. In order to explain the stronger tendency of halogenocadmate(II) complexes to form layered structures as compared to halogenozincate(II), ab-initio calculations were performed. The stability of MX5
3-(M = Cd, Zn; X = Cl, Br) is compared. Isolated ZnX5
3- and CdBr5
3- ions are not stable. On the other hand a trigonal bipyramid CdCl5
3- ion is considered to be subtly stable in the crystal mainly due to Coulomb attractive interactions between the positively charged metal cation Cd2+ in a CdCl3- fragment and two Cl- ions.
Thermodynamic Properties of EuCl2 and the NaCl-EuCl2 System
Authors: Da Silva F. , Rycerz L. , Gaune-Escard M. 
Published: February 2015

Abstract
The temperature and enthalpy of the phase transition and fusion of EuCl2 were determined and found to be 1014 K, 11.5 kJ mol-1and 1125 K, 18.7 kJ mol-1 , respectively. Addition­ ally, the heat capacity of solid EuCl2 was measured by Differential Scanning Calorimetry in the temperature range 306 -1085 K. The results were fitted to the linear equation C0
p,m = (68.27 + 0.0255 T/K) J mol -1 K-1 in the temperature range 306 -900 K. Due to discrepancies in the liter­ ature on the temperature of fusion of EuCl2, the determination of the NaCl-EuCl2 phase diagram was repeated. It consists of a simple eutectic equilibrium at Teut = 847 K with x(EuCl2) = 0.49.
Calorimetric Investigation of MCI-EuCI2 Melts (M = Na, K, Rb)
Authors: Da Silva F. , Rycerz L. , Gaune-Escard M. 
Published: February 2015

Abstract
The molar enthalpies of mixing (ΔmixHm) of MCl-EuCl2 (M = Na, K, Rb) liquid binary systems were measured at 1138 K over the whole composition range by direct calorimetry. A Calvet type calorimeter was used, and mixing of the two liquid components was achieved by the ampoule break-off technique under argon at atmospheric pressure. The enthalpy of mixing of these systems is negative over the whole composition range with a minimum of approximately -0.5, -3.5 and -4.5 kJ mol-1 for M = Na, K, Rb, respectively. The least-squares coefficients A, B, C in the equation A (kJ mol-1) = A + B x + C x2, where λ is an interaction parameter, are reported. From the trend observed in these MCl-EuCl2 systems it was possible to estimate the mixing enthalpy of the CsCl-EuCl2 system.
Control and Adaptation of Spatio-temporal Patterns
Authors: Diebner Hans H. , Hoff Axel A. , Mathias Adolf , Prehn Horst , Rohrbach Marco , Sahle Sven 
Published: February 2015

Abstract
We apply a recently introduced cognitive system for dynamics recognition to a two-dimensional array of coupled oscillators. The cognitive system allows for both the control and the adaptation of spatio-temporal patterns of that array of oscillators. One array that shows Turing-pattems in a self-organizational manner is viewed as an externally presented dynamics (stimulus) which is mapped onto a mirror dynamics, whereby the latter is capable to simulate (simulus). Two of the parameters of the stimulus are thereby regarded to be unknown and have to be estimated by the cognitive system. The cognitive system itself consists of dynamical modules that are stimulated by the external dynamics in the sense of Pyragas' external force control mechanism and thereby yield measures of how good they match the stimulus. These measures are used as weights to construct the simulus. The adaptation process is performed "on the fly", i. e., without the storage of data. The proposed cognitive system, therefore, is a prominent candidate for the construction of a control device for a permanent real time observation of an external dynamical system in order to interfere instantaneously when necessary.
Conductivities of Room Temperature Molten Salts Containing AlCl3, Measured by a Computerized Direct Current Method
Authors: Hsu Hsin-Yi , Yang Chao-Cheng 
Published: February 2015

Abstract
The conductivities of the binary room-temperature molten salt systems AlCl3-N-n-butylpyridinium chloride (BPC), AlCl3-l-ethyl-3-methylimidazolium chloride (EMIC) and AlCl3-benzyltriethylammo-nium chloride (BTEAC) have been measured at different temperatures and compositions by a d.c. four-probes method.
There is a maximum of the conductivity at 50 mol% AlCl3 in the AlCl3-BPC and AlCl3-EMIC systems at 40 to 80 °C, their activation energies being relatively low (20.79 and 14.76 kJ/mol, respec­ tively). As to the A1C13-BTEAC system, there is an irregular change in the conductivity at 40-70 mol% AlCl3 in the temperature range 50 to 80 °C. The conductivities of the three RTMS are in the order AlCl3-EMIC > AlCl3-BPC > AlCl3-BTEAC, the reason being discussed.
Effect of Li Content on the DSC and Electrical Conductivity of (Li1-xKx)2SO 4 Mixed Crystals
Authors: Ahmad M. M. , Hefnia M. A. 
Published: February 2015

Abstract
Differential scanning calorimetry on (Li1-x Kx)2SO4 mixed crystals, where x = 0.01, 0.1, 0.3 and 0.5, revealed that, as the potassium content increases, the first high temperature phase of the intermediate LiKSO4 phase at T - 432 °C grows and shifts to higher temperature, and a double-phase mixture consisting of LiKSO4 and Li2SO4 exists for x< 0.5. Ionic conductivity measurements on (Li1-xKx)2SO4 mixed crystals for x < 0.5 did show that the electrical conductivity increases as the Li2SO4 concentration increases, with an average activation energy of 0.9 eV. The enhanced electrical conductivity is primarily a result of the increase in the Li+ ion (charge carriers) concentration and/or the formation of a diffuse space charge layer at the interface between the two phases.
The Value of Sommerfeld's Finestructure Constant as a Consequence of the Planck-Aether Hypothesis
Authors: Winterberg F. 
Published: February 2015

Abstract
A value of the finestructure constant at the unification eneigy is obtained by a dimensional analysis of quantum gravity and fluid dynamics. The derivation assumes that the vacuum is a superfluid made up of positive and negative Planck mass particles obeying an exactly nonrelativistic law of motion with Lorentz invariance a low energy approximation. The dimensional analysis presented gives a value for the finestructure constant in good agreement with the empirical value 1/α = 25.
Induced Smectic-G Phase through Intermolecular Hydrogen Bonding Part VIII: Phase and Crystallization Behaviours of 2-(p-n-heptyloxybenzyIidene imino)-5-chIoro-pyridine: p-n-alkoxybenzoic acid (HICP:n ABA) Complexes
Authors: Srinivasulu M. , Satyanarayana P. V. V. , Kumar P. A. , Pisipatia V. G. K. M. 
Published: February 2015

Abstract
New intermolecular H-bonded liquid crystalline complexes, viz., 2-(p-n-heptyloxybenzylidene imi-no)-5-chloro-pyridine:p-/z-alkoxybenzoic acid; (HICP:nABA) (where n denotes the alkoxy carbon num­ bers 3 to 10 and 12) exhibiting smectic-F (n = 12) and smectic-G phases have been synthesized and char­ acterized by Thermal Microscopy and Differential Scanning Calorimetry (DSC). Detailed IR (solid and solution states) analysis confirms the existence of intermolecular H-bonding between the pyridyl nitro­ gen and the COOH group of the p-n-alkoxybenzoic acid moiety. The phase behaviour of the series is discussed in the light of reported data on free p-n-alkoxybenzoic acids. The crystallization kinetics of a representative complex, using the DSC technique, is discussed. The mechanism of the crystal growth of the new crystalline smectic-G phase is computed with the Avrami equation.
Density Measurement of Molten KHF2
Authors: Matal Oldřich , Žaloudek Josef , Cigánek Frantisek , Slavíček Pavel , Žmij Bronislav , Nejedlý Milan 
Published: February 2015

Abstract
An apparatus has been manufactured to measure the density of molten KHF2. A linear dependence of the density on temperature is found in the range of 280-450 °C.
Quantum Effect on Collisions in Electron-positron Plasmas
Authors: Jung Young-Dae 
Published: February 2015

Abstract
Quantum effects on the electron-positron scattering are investigated in electron-positron plasmas. The corrected Kelbg potential, taking into account the quantum effects, is applied to describe the electron-positron interaction potential in electron-positron plasmas. The Bom approximation is considered to obtain high-energy electron-positron scattering cross sections. The results show that the differential electron-positron scattering cross sections increase with increasing thermal de Broglie wavelength, i.e., decreasing plasma temperature. The differential electron-positron scattering cross sections decreases with increasing collision energy. It is also found that the quantum effects on the differential scattering cross section are small for forward and backward scattering angles.
Structure and Binding of Ionic Clusters in Th and Zr Chloride Melts
Authors: Akdeniz Z. , Tosi M. P. 
Published: February 2015

Abstract
We discuss microscopic ionic models for the structure and the binding of small clusters which may exist as structural units in molten ThCl4 and ZrCl4 and in their mixtures with alkali halides according to Raman scattering studies of Photiadis and Papatheodorou. The models are adjusted to the two isolated tetrahedral molecules. Appreciably higher ionicity is found for ThCl4 than for ZrCl4, and this fact underlies the strikingly different behaviour of the two systems in the dense liquid state -in particular, a molecular-type structure for molten ZrCl4 against a structure including charged oligomers in molten ThCl4.
Structure of Rare-earth/Alkali Halide Complexes
Authors: Akdeniz Z. , Önem Z. Çiçek , Tosia M. P. 
Published: February 2015

Abstract
Vapour complex formation of rare-earth halides with alkali halides strongly increases the volatility of these compounds. We evaluate the structure taken by such complexes having the chemical formulas MRX4, M2RX5 and M3RX6, where X = F or Cl and typically M = Li or Na and R = La. The roles played by the two types of metal atom is investigated in MRX4 complexes by also taking M = K, Rb or Cs and R = Gd or Lu. The main predictions that emerge from our calculations are as follows: (i) in MRX4 a fourfold coordination of the rare-earth atom is accompanied by twofold or threefold coordination of the alkali atom, the energy difference in favour of the twofold-coordination state being about 0.3 eV in the case of the LiF complexing agent but even changing sign as the ionic radius of either the alkali or the halogen is increased; (ii) in M2RX5 a fivefold coordination of the rare-earth atom is energetically more stable than a fourfold one, by again not more than about 0.3 eV; (iii) in M3RX6 the fivefold and sixfold coordinations of the rare-earth atom are energetically competitive; and (iv) in both M2RX5 and M3RX6 each coordination state can be realized in various forms that differ in detail but are close in energy. Bond fluctuations and disorder around the rare-earth atom can be expected to be a general feature at elevated temperatures, both in the vapour and in liquid rare-earth/alkali halide mixtures.
Current Efficiency Obtained with SnO2-based Inert Anodes in Laboratory Aluminium Cell
Authors: Popescu Ana-Maria 
Published: February 2015

Abstract
A systematic study of the current efficiency (CE) in a laboratory aluminium cell with SnO2-based inert anodes was carried out by measuring the overall amount of oxygen relieved at the anode, using two different methods.
Inert ceramic anodes of 96% SnO2, 2% Sb2O3, 2% CuO in wt% composition were prepared and investigated. The influence of: temperature, current density, anode-cathode distance, cryolitic ratio, content of alumina and different additives was studied. At the same time the influence of the age of boron nitride (BN) sheath of the inert anode on the CE was evaluated.
Electrochemical and Thermodynamic Properties of EuCl3 and EuCl2 in an Equimolar NaCl-KCl Melt
Authors: Kuznetsov S. A. , Rycerz L. , Gaune-Escard M. 
Published: February 2015

Abstract
The electroreduction of EuCl3 in an equimolar NaCl-KCl mixture was studied at 973 -1123 K by different electrochemical methods. This reduction of Eu(III) in NaCl-KCl melt occurs via two successive reversible steps involving transfer of one and two electrons. The diffusion coefficients of Eu(III) and Eu(II) were measured by linear sweep voltammetry and chronopotentiometry. The values found by these methods are in a good agreement. The standard rate constants for the redox reaction Eu(III) + e~ Eu(II) were calculated from cyclic voltammetry data. The sluggish kinetics of this reaction is discussed in terms of substantial rearrangement of the europium coordination sphere. Special attention was paid to the choice of working electrodes for the study of electrode reactions. The formal standard potentials E*E u (^ /Ba, E* eU (hr/eu and the formal redox potentials ^*Eu(ni)/Eu(ii) were determined from open-circuit potentiometry and linear sweep voltammetry data. The free Gibbs energy changes for the reaction EuCl3(so1) EuCl2(SOi.) + 1/2 Cl2(g.) and the equilibrium constants of the metal-salt reaction 2Eu(III) + Eu 3 Eu(II) were calculated. The thermodynamics of the formation of dilute solutions of europium di-and trichloride in an equimolar NaCl-KCl melt were determined. It was shown that electrochemical transient techniques give the possibility of the determination of the relative partial molar mixing enthalpy of europium trichloride and dichloride in NaCl-KCl melt.
The Electrical Conductivity of Molten (Ag, Cd1/2)Br
Authors: Wojakowska Alina , Gòrniak Agata 
Published: February 2015

Abstract
The electrical conductivity of molten (Ag, Cd1/2)Br has been determined as a function of temperature in the whole range of compositions. The resulting activation energy values and the conductivity isotherm at 850 K are compared with those of the system (Ag, Cd1/2)Cl.