bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the Polarity of the Medium on the Alkaline Hydrolysis of n-Butyl Acetate in Hydroalcoholic Mixtures
Authors: Celdrán M. S. , Ramón M. V. , Martínez P. 
Published: February 2015

Abstract
The kinetics of the alkaline hydrolysis of n-butyl acetate have been studied in water and in hydroalcoholic mixtures. The rate constants, activation energies, frequency factors, entropies, Gibbs free energies and enthalpies of activation have been determined. The radii of the activated com­ plexes have been calculated and related to their degree of solvation. A possible reaction mechanism is formulated.
The Solid State Displacement Reaction CsCl + Nal → Csl + NaCl
Authors: Massarotti Vincenzo , Flor Giorgio , Riccardi Riccardo 
Published: February 2015

Abstract
The solid state reaction CsCl+Nal → CsI+NaCl was investigated, employing diffusion couples with two different contents of divalent cation impurities, in the temperature range 350-419 °C.
From kinetic determinations, inert marker experiments and X-ray diffraction analysis it was possible to deduce that the rate − determining step is the diffusion of I- in CsI via VI.
How Constant are Fundamental Physical Quantities?
Authors: Eichendorf W. , Reinhardt M. 
Published: February 2015

Abstract
We reinvestigate Dirac's large number hypothesis (LNH) which implies the variation of one or more basic physical constants with time. We show that the ratio of the inertial masses of elementary particles and the fine structure constant a do not vary with time in the LNH.
Using geochemical data on the surface temperature of the earth in the precambrian we can rule out Dirac's conjecture that the gravitational constant G is inversely proportional to cosmic epoch with and without matter creation. Our limit on Ġ/G is one of the best available. We can exclude Gamow's proposal to save the LNH by a variation of the elementary charge e. We also put an upper limit on the variation of the mass of elementary particles.
With the data available at present, we cannot rule out Dirac's LNH if either the mass of elementary particles or the velocity of light and Planck's constant are time dependent. A few other models of variable physical constants are also discussed and excluded.
On Thermalisation of Energetic Charged Particles in Fusion Plasma with Quantum Electrodynamic Considerations
Authors: Ray P. S. , Hora H. 
Published: February 2015

Abstract
The process of energy loss of charged heavy particles in plasma has been discussed taking into consideration photon emissions by electrons of plasma during scattering as is necessitated by quantum electrodynamics. Although the range in general increases with temperature, it is found that the numerical formula of former treatment giving a range as T3/2 is not in general, obeyed. The range is susceptible to the initial energy as well as mass of the heavy particle as can be seen from the cases of alphas and reaction protons for DT, DD(→p + He3) and D He3 plasmas.
Temperature Dependence of the Thermal Resistivity of Noble Metals
Authors: Gupta O. P. , Kharoo H. L. , Hemkar M. P. 
Published: February 2015

Abstract
The temperature dependence of the thermal resistivity of copper, silver, and gold is calculated within the free electron approximation and using the anisotropic continuum dispersive model proposed by Sharma and Joshi for the lattice dynamics of cubic metals. The phonon spectrum has been calculated with the help of the modified Houtson's spherical six-term procedure as elaborated by Betts at al. Bardeen's matrix elements for the scattering of free electrons have been incorporated into the variational expression developed for the Boltzman transport equation. The theoretically calculated resistivity values of copper, silver, and gold are in reasonable agreement with the experimental data.
“Syncope Implies Chaos” in Walking-stick Maps
Authors: Rössler Otto E. 
Published: February 2015

Abstract
A number of 3-variable chemical and other systems capable of showing 'nonperiodic' oscillations are governed by walking-stick shaped maps as Poincare cross-sections in state space. The 2-dimensional simple walking-stick diffeomorphism contains the one-dimensional 'single-humped' Li-Yorke map (known to be chaos producing) as a 'degenerate' special case. To prove that chaos is possible also in strictly 2-dimensional walking-stick maps, it suffices to show that a homoclinic point (and hence an in­ finite number of periodic solutions) is possible in these maps. Such a point occurs in the second iterate at a certain (modest) 'degree of overlap' of the walking-stick map. At a slightly larger degree, a 'nonlinear horseshoe map' is formed in the second iterate. It implies presence of periodic trajectories of all even periodicities (at least) in the walking-stick map. At the same time, two major, formerly disconnected, chaotic subregimes merge into one. Diagnostic criterion: presence of 'syncopes' in an otherwise non-monotone sequence of amplitudes.
Thermoelectric Power of the Molten Systems PbCl2—MeCl (Me = Li, Na, K, Rb, Cs)
Authors: Schiraldi Alberto , Pezzati Elisabetta 
Published: February 2015

Abstract
Initial thermoelectric power determinations where carried out by means of Pb electrodes and Cl2 electrodes thermocells on the molten system PbCl2-MeCl (Me = Li, Na, K, Rb, Cs).
Combinations of the results coming from the two kinds of thermocells allowed to verify Rein-hold's relation and to estimate the partial molar formation and excess entropies of PbCl2.
Ligand-Field Calculations on Pseudo-Tetragonal Ni(II) Compounds
Authors: Vermaas A. , Groeneveld W. L. , Reedijk J. 
Published: February 2015

Abstract
Magnetic susceptibility, magnetic saturation, ligand field and EPR measurements are reported for the compounds Ni(5-methyl pyrazole) 4X2, (X = Cl, Br, I). All data are interpreted using ligand-field calculations, yielding parameters D q, D s, D t, B, C, g∥, g⊥,D, ζ∥, ζ⊥, and k.
All data fit with a single set of parameters. The zero-field splittings and g values are determined from the magnetic measurements, whereas the excited state splittings are determined from the ligand-field spectra.
In studying the relation between the zero-field splitting of the Ni(II) ion and both the spinorbit coupling and spectroscopic energy parameters, a description using an anisotropic spin-orbit coupling gave the most reliable fit.
In addition, known ligand-field spectra and D values of Ni (pyrazole) 4X2, (X = Cl, Br, I) were considered. The derived energy parameters of the corresponding pyrazole and 5-methyl pyrazole compounds are very similar.
Fall-Off Curves for the Reaction ClO + NO2( + N2) ClONO2 (+N2)
Authors: Zellner Reinhard 
Published: February 2015

Abstract
Fall-off curves for the reaction ClO+NO2(+N2)→ClONO2(+N2) at 300 and 220 K have been calculated from Kassel integrals by use of a theoretically derived high pressure limit and the experimentally determined low pressure limit as reference points. The reaction is found to deviate considerably from the low pressure limit at pressures larger than 10 Torr. Effective rate constants for the use in atmospheric models of chlorine nitrate formation are derived.
Effect of Tl Concentration on the Thermoluminescence of Deformed NaCl:Tl Phosphors
Authors: Joshi R. V. , Joshi T. R. 
Published: February 2015

Abstract
It is known that thermal and/or mechanical pretreatment influences the luminescent behaviour of phosphors. It has been reported that mechanically pretreated NaCl : Tl specimens, exposed to ultraviolet radiation, exhibit a pronounced glow peak at 420 K. The present work concerns the study of the intensity of this peak as a function of impurity concentration. There is a remarkable growth in the intensity of the 420 K glow peak with decreasing concentration. This can be explained on the basis of the interaction between impurity ions and moving dislocations.
EPR of Mn2+ in Pr2Mg3(NO3)12 · 24H2O Single Crystals
Authors: Jain V. K. , Srinivasan T. M. 
Published: February 2015

Abstract
EPR of Mn2+ in Pr2Mg3(NO3)12·24H2O single crystals has been studied at X-band. Mn2+ substitutes two inequivalent Mg2+ sites. The spin-Hamiltonian analysis of the EPR spectra is presented at 298 K as well as 77 K.
Sextische Zentrifugalverzerrungskonstanten und Mikrowellen-spektren bis 130 GHz von 12C32SF35Cl
Authors: Hamm R. , Günther H. , Zeil W. 
Published: February 2015

Abstract
It has been demonstrated that Watson's energy formula for the centrifugal distorted rotor is no longer sufficient for highly excited states. For the CSFCl molecule, the formula can only be used up to a limit of about J = 30. Beyond this rotational quantumnumber Watson's sextic Rotational Hamiltonian should be used for fitting the rotational energy parameters. Good results were obtained up to J = 70 using the sextic Hamiltonian and diagonalizing numerically the energy matrix set up in the rigid symmetric rotor basis. The sextic centrifugal distortion constants could be determined to a sufficient degree of exactness, i. e. the absolute value of the constants is considerably greater than the errors.
Microwave Spectrum and Barrier to Internal RotationinCH3COC15N
Authors: Pandey G. K. , Dreizler H. 
Published: February 2015

Abstract
The ground state rotational spectra of the 15N isotopic species of acetyl cyanide have been measured in the region from 8 to 40 GHz. The rotational and centrifugal distortion constants have been determined by a least squares fit to about 38 transition frequencies with J ≦ 14. The potential barrier parameter V3 and the angle a between the top axis and the 'a-axis' have been determined by a least squares of the (A-E) splittings of about 27 transitions. The methyl top moment of inertia was fixed at 3.14 amu Å2
The Field Within a Commercial EI/FI Source of a Mass Spectrometer
Authors: Feys J. P. R. , Mey G. De , Claeys E. G. , Kelen G. P. Van der 
Published: February 2015

Abstract
A novel method for the calculation of the potential distribution in a mass spectrometer source is presented. It consists in solving a Green integral equation and applies both to the FI and EI mode of a CEC 21-110 C mass spectrometer source.
A Study of the Electronic Spectrum of 3,4-Benzphenanthrene Cation Radical
Authors: Khan Zahid H. , Khanna B. N. 
Published: February 2015

Abstract
The electronic spectrum of 3,4-benzphenanthrene cation radical is studied for the first time experimentally as well as theoretically. The cation radicals have been produced in boric acid glass by photooxidation and the absorption spectrum is measured in the region 200-1400 nm. An interpretation of the spectrum is given on the basis of Pariser- Parr (PP) and Free Electron (FE) molecular orbital calculations using limited configuration interaction. It is found that the results based on the PP method are in better agreement with experiment as compared to the FE method. Furthermore, the spectral shifts and other variations observed between the spectra of the cation and anion radicals are attributed to the characteristics of these species.
Der Einfluß des Phonon -Mitzieheffektes auf die thermoelektrischen Koeffizienten in Metallen / Influence of Phonon Drag on the Thermoelectric Coefficients in Metals
Authors: Roloff D. , Simon G. 
Published: February 2015

Abstract
The system of coupled Boltzmann transport equations for electrons and phonons in a metal is considered in the absence of a magnetic field. Usually these equations are decoupled by “Bloch′s assumption”, that is the phonon gas is considered to stay in equilibrium with respect to the trans­ port equation for the electrons.
It is shown that the coupled system of equations has finite solutions only if some other relaxation process than the electron-phonon interaction is present, for instance the phonon-phonon-interaction. With some simplifying assumptions the full system of equations is solved for high temperatures. The contributions of the phonon-drag to the thermoelectric transport coefficients are derived and discussed.
A Dielectric Instability of a Fermion Gas in a Random Potential
Authors: Dallacasa V. 
Published: February 2015

Abstract
A dielectric instability of a collection of charged fermions interacting via Coulomb forces and subjected to a random external field is pointed out. It is shown that, as a result of localization produced by the random potential, an RPA Coulomb field can generate a dielectric instability, both static or frequency dependent, resulting in a static or oscillating crystalline arrangement of the fermions. In simple metals, such as the alkali metals, this mechanism is shown to provide an explanation of the existence of the crystal lattice and of acoustic phonons.
On the Influence of Intra - and Inter-Molecular Hydrogen Bonding on the Excited State Lifetime of Indigo Dyes
Authors: Windhager W. , Schneider S. , Dörr F. 
Published: February 2015

Abstract
It is shown that intramolecular hydrogen bonding can give rise to very fast nonradiative desactivation of the S1 -state of indigo dyes. In those derivatives, which lack the possibility of internal hydrogen bonds, hydrogen bonding to suitable solvent molecules can provide the channel for fast radiationless transitions. As a consequence, drastic effects on the S1 -state lifetime are observed both as a function of solvent and/or temperature.
Proton Magnetic Resonance and Molecular Motion in Solid Methyl-Piperidines and Piperazines
Authors: Schüler R. , Brücher L. , Müller-Warmuth W. 
Published: February 2015

Abstract
The 1H-NMR spin-lattice relaxation time and lineshape in solid 2-, 3-, and 4-methyl-piperidine, in 2-and N-methyl-piperazine, and in NN′-diinethyl-piperazine has been measured from low temperatures to the melting point. For all cases, the experimental data can be described by classical rotation of the methyl group. Activation energies governing this motion are between 9 and 14 kJ/mole. Second moments are reduced from about 25 G2 to 17 G2. No further line-narrowing was observed.
Rotational Spectrum , Electric Dipole Moment, Quadrupole Coupling , and Partial r0- Structure of 3 -Cyanothiophene
Authors: Wiese J. , Sutter D. H. 
Published: February 2015

Abstract
The microwave rotational spectrum of the most abundant species of 3-Cyanothiophene was investigated for the ground vibrational state. Rotational constants and centrifugal distortion constants are given. The electric dipole moment components μa and μb and the 14N-quadrupole coupling constant X + = X bb + X cc were determined from the Stark-effect splittings and hfs-splittings respectively. The experimental results are compared to CNDO/2 calculations and are discussed with reference to ring distortion.
Notizen: The Dipole Moment Function of HF Molecule Using Morse Potential
Authors: Chan Y. K. , Rao B. S. 
Published: February 2015

Abstract
The radial Schrödinger wave equation with Morse potential function is solved for HF molecule. The resulting vibration-rotation eigenfunctions are then used to compute the matrix elements of (r - re)n. These are combined with the experimental values of the electric dipole matrix elements to calculate the dipole moment coefficients, M 1 and M 2.
Attenuation and Velocity of Ultrasonic Waves in Amorphous Selenium in the Vicinity of the Glass Transition
Authors: Kittinger Erwin 
Published: February 2015

Abstract
Attenuation and velocity of longitudinal ultrasonic waves have been measured in a-Se in the vicinity of the glass transition. Both quantities are shown to be affected significantly by the stabilization process below the glass transition temperature Tg. Equilibrium values of sound velocity are also reported for the range 25 °C to 45 °C. The decrease (increase) of attenuation (velocity) during stabilization is reversed at higher temperatures. The connection of both quantities is discussed in terms of an effective temperature which allows the approximate determination of equilibrium values of attenuation (and possibly of other structure related properties) from measurements performed in nonequilibrium states.
Identification of Thermoluminescence Traps in CaWO4 and BaWO4 by EPR Measurements
Authors: Hofstaetter A. , Planz J. , Scharmann A. 
Published: February 2015

Abstract
In calcium-and barium tungstate crystals both containing molybdenum and phosphorus, para­magnetic centres are created by X-ray irradiation at room temperature. Two kinds of centres are identified by EPR measurements; an electron trapped at a molybdate complex and a hole trapped at a phosphate complex. The EPR parameters of the hole centres are temperature dependent indicating motional effects. A connection of these two traps with the observed thermoluminescence is found for both crystals.
207Pb Magnetic Shielding Anisotropy in Pb(NO3)2, PbCO3, PbCrO4, PbMo04 and PbWO4 by Fourier Transform NMR
Authors: Nolle A. 
Published: February 2015

Abstract
The NMR signals of 207Pb have been observed in powder samples of Pb (NO3)2, PbCO3 , PbCrO4 , PbMoO4 and PbWO4 using a Fourier transform apparatus. All the observed signals are asymmetrical, indicating anisotropics of the magnetic shielding σ33- σ11 with values between - 56ppm for Pb(NO3)2 and - 884 ppm for PbCrO4 . The principal elements of the shielding ten­ sors σ11 , σ22 , σ33 are given relative to the Pb2+ ion at infinite dilution in H2O and can be referred to the free lead atom with the known shielding constant of earlier measurements.
Die Bildung negativer Ionen bei Elektronenstoß auf WF6 / Formation of Negative Ions from Electron Impact on WF6
Authors: Wall R. de , Neuert H. 
Published: February 2015

Abstract
The formation of negative ions from WF6 by bombardment with electrons has been studied using a conventional mass spectrometer with an electron impact ion source. At higher electron energies WF6
--, WF5
--, WF4
--, WF3
--, and F-- ions have been found. Appearance potentials of WF6
--, WF5
--, WF4
--, and F- resulting from dissociative attachment processes are given. WF4
- and WF2
- have been observed from the decay of a higher excited WF6
- at about 70 eV energy. The electron affinity of WF5 has been derived as 1.25±0.2 eV; the values of D(WF4-F)≦5.5±0.2 eV and E A(WF4) =2.6 eV are suggested.
Solar Energy-Assisted Electrochemical Splitting of Water. Some Energetical, Kinetical and Catalytical Considerations Verified on MoS2 Layer Crystal Surfaces
Authors: Tributsch H. 
Published: February 2015

Abstract
Kinetical, energetical and solid state considerations were elaborated in a search for suitable electrodes for the oxidation of water with visible light. They led to layer type transition metal dichalcogenides and to the photo-electrochemical utilization of optical d-d-transition which do not break chemical bonds. MoS2 was selected as a promising compound and it was actually shown to react with water on illumination with light between 400 and 715 nm. At low electrode potentials the liberation of small quantities of molecular oxygen was traced with polarographic techniques. The main portion of the oxidation products of water was, however, found to be lost for the oxydation of crystal bound sulfur to sulfate. An improvement of this situation in favour of an increased rate of oxygen evolution has been accomplished by means of a redox-catalyst, tris (2,2'-bipyridine) -ruthenium (II), which is oxidized through photochemically generated holes from the MoS2 4 dz²­­- valence band and channels them into oxygen-evolution through nucleo-philic addition of hydroxide. A molecular mechanism was elaborated for the photoelectrochemical oxidation of water on MoS2 and its conclusions tested by investigating the oxidative behaviour of various additional layer-type transition metal compounds. It involves a hole mediated valence change of molybdenum with an intermediate formation of a 5-valent molybdenum hydroxide. A basic kinetical and energetical similarity is suggested with the function of manganese reaction centers in photosynthesis.
Numerical Calculations on Reflection Processes of Ionizing Shocks on the End Wall of a Shock Tube
Authors: Takano Yasunari , Akamatsu Teruaki 
Published: February 2015

Abstract
Numerical calculations have been made about shock reflection processes in ionizing argon on the end wall of a shock: tube. The two-step Lax-Wendroff scheme was employed to solve time-dependent one-dimensional inviscid flow problems for ionizing gases. Complicated flowfields were found to occur due to interactions between ionization relaxation processes and reflected shocks. Calculations were performed for three cases: incident-shock Mach number M s = 16 and initial pressure p1 = 1 torr; Ms = 14 and p1 = 3 torr; M s = 12 and p1 = 5 torr.
Interdiffusion Studies in Liquid Bismuth-Antimony Alloys
Authors: Lamparter Peter , Steeb Siegfried 
Published: February 2015

Abstract
The composition dependence of the interdiffusion coefficient in Bi-Sb melts has been measured in the temperature range from 656 °C to 1010 °C by use of the long-capillary method and electron piobe microanalysis. The measured data can be represented as a function of the temperature by an Arrhenius law: D=D0 exp (-Q/R T).
The concentration dependence of the parameters D0 and Q is given. Analysis of the variation of Q with composition leads to the conclusion that Bi-Sb alloys show more metallic behaviour than unalloyed Bi or unalloyed Sb.
This result is in agreement with the structure of the Bi-Sb melts.
A Topological Formula for Total π-Electron Energy
Authors: Gutman Ivan 
Published: February 2015

Abstract
Total π-electron energy E is presented as a sum of first-neighbour interaction terms λ and contributions of cycles ζ [Equation (2)]. The main conclusion of the work is that the total effect of λ's is a constant, independent of the molecular structure. Therefore, E is an additive function of ζ′s only.
Hydrogen Stark Broadening by Model Electronic Microfields
Authors: Seidel Joachim 
Published: February 2015

Abstract
The Method of Model Microfields proposed by Brissaud and Frisch is applied to calculate Stark broadened profiles of hydrogen lines in the static ion approximation. Numerical results for L-α, H-α, and H-β are found to be in good agreement with those derived from the unified theory by Vidal, Cooper, and Smith over a wide range of plasma densities and temperatures. This demon­ strates that reliable line profiles may be obtained from the microfield distribution and covariance alone, more complicated statistical features being less important in this context.
On an Almost Complex Manifold Approach to Elementary Particles
Authors: Ławrynowicz Julian , Wojtczak Leszek 
Published: February 2015

Abstract
An almost complex manifold description of elementary particles is proposed which links the approaches given independently by J. Ławrynowicz and L. Wojtczak, and by C. von Westenholz. This description leads to relations between the curvature form of an almost complex manifold, which accounts for the symmetry classification schemes within the frame of principal fibre bundles, and a curved Minkowski space-time via induced smooth mappings characterizing nuclear reactions of type N+π⇄N, where N is some nucleon and π the virtual π-meson of this reaction. Both approaches follow the same main idea of D. A. Wheeler developed in a different way by A.D. Sakharov.
Multilevel Models of Krypton for the Application to Stepwise Ionization Relaxation Processes
Authors: Bergmann L. , Demmig F. 
Published: February 2015

Abstract
A four step model and two five step models of krypton are developed for application to stepwise ionization relaxation. The four step model is preferred out of practical and economical grounds. The corresponding rate equations for collisional excitation and ionization are given assuming ladder climbing for the electrons. Selected results of an application of the model to ionization relaxation in shock waves are reported.