bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of Pierre Birnbaum's A Tale of Ritual Murder in the Age of Louis XIV: The Trial of Raphaël Lévy, 1669
Authors: Plakotos Giorgos
Published: February 2015

Pierre Birnbaum, A Tale of Ritual Murder in the Age of Louis XIV: The Trial of Raphaël Lévy, 1669, Stanford: Stanford University Press, 2012. 178 pp, 12 illus.
Review of Lina Venturas and Lambros Balsiotis (eds), Το έθνος πέραν των συνόρων: «Ομογενειακές» πολιτικές του ελληνικού κράτους
Authors: Tsapogas Michael
Published: February 2015

Lina Venturas and Lambros Baltsiotis (eds), Το έθνος πέραν των συνόρων: «Ομογενειακές» πολιτικές του ελληνικού κράτους [The nation beyond borders: the ‘diaspora’ policies of the Greek state], Vivliorama: Athens, 2013. 510 pp
Effects of wall waviness and temperature variations on the fluid flow and natural convection in an inclined corrugated channel
Authors: Amini Meysam , Najafi Mohammad , Dorosti Qaran , Biglarian Hassan , Ghasemi Esmaeil
Published: February 2015

A parametric study involving the effects of some combinations of parameters, in particular, different combinations of the Rayleigh number, amplitude, temperature, and inclination angle of a two-dimensional long wavy-walled channel on a laminar incompressible fluid flow and natural convection within the channel is performed. The considered channel has an undulated wall as one side of the channel, and a parallel flat wall at a differentially different temperature as its counterpart. The channel sustains variable inclination angle, variable wavy wall amplitude, and variable temperature-difference between its two walls. A perturbation technique in terms of the small waviness of the undulated wall is performed to obtain a set of non-linear ordinary differential equations for the main flow and its perturbations. Solving this set of equations determines the streamline and temperature profiles for the imposed varying parameters. The results reveal that the fluid velocity along the channel axis increases with increasing the Rayleigh number, but decreases with increasing the channel inclination angle. The results also show that eddies appeared due to the steep undulations intensify as the temperature-difference between the two channel walls increases. The veracity of the present work is demonstrated through comparing the obtained results with those available in the literature.
Semiempirical Calculation of the Rotational Barrier and Valence Force Constants in Fluorocarbonylsulfenyl Chloride
Authors: Jubert A. H. , Védova C. O. Della , Varetti E. L. , Piro O. E. , Aymonino P. J.
Published: February 2015

The rotational barrier about the C-S bond in fluorocarbonylsulfenyl chloride [FC(O)SCl] is investigated using the CNDO method. The results confirm the existence of planar eis and trans conformers and the higher stability of the latter, as suggested by previous vibrational results.

The valence force constants in FC(O)SCl were also calculated and the values obtained compare favourably with results from a previous normal coordinate calculation and with those of related compounds.
Rotational Spectrum of Methylcyanoacetylene A New Millimeter Wave Spectrometer
Authors: Bester M. , Tanimoto M. , Vowinkel B. , Winnewisser G. , Yamada Koichi
Published: February 2015

The ground state rotational spectrum of methylcyanoacetylene, CH3CCCN, has been observed between 8 and 90 GHz, yielding precise rotational constants and a determination of the nuclear hyperfine costant eqQ = -4.0 ± 0.2 MHz. The millimeter wave spectra (70 - 90 GHz) were obtained with a newly constructed spectrometer, employing a synthesizer - controlled reflex klystron as source.
On the Distribution of Isotopes in a Separation Column in Countercurrent Electromigration of Molten Binary Mixtures
Authors: Okada Isao , Lundén Arnold
Published: February 2015

In countercurrent electromigration of molten binary mixtures with a common anion in which each cation is composed of two isotopes, the less mobile cation is enriched toward the anode, and, at the same time, the isotopes of this cation become distributed in a complicated way. Thus, the zone next to the anode where the heavy isotope is enriched is immediately followed by a region where a slight enrichment of the light isotope occurs, while for the more mobile cation the heavy isotope is enriched in both these regions. This phenomenon has been observed in experiments with the systems (Li-K)NO3 and (Li-K)Cl and it has also been reproduced by analyzing the flow equations for the constituent components numerically with a computer. It is verified that the existing formulation for the calculation of the elementary separation factor holds independent of whether there is such an anomaly in the isotope distribution for the less mobile cation.
Chronoamperometric Determination of Solid State Diffusion Coefficients in Copper-Gold Alloys Using a Molten Salt Electrolyte
Authors: Lantelme F. , Chemla M.
Published: February 2015

The intermetallic diffusion coefficient in Cu-Au alloy between 400 °C and 550 °C is measured by chronoamperometry using a Cu-Au electrode in a molten LiCl-KCl electrolyte containing small amounts of Cu+ ions. The current response to a defined constant potential step is controlled by the rate of diffusion in the alloy electrode. The mathematical treatment developed by introducing the Boltzman transformation shows that the current density is a linear function of the reciprocal square root of time whatever the dependence of D versus concentration is.

The method is applied to cathodic as well as anodic potential pulses which correspond to surface alloying or dissolution i.e. diffusion "in" or "out" the sample. The shift of the interface due to the copper deposition or dissolution is considered according to the Oldham and Raleigh's method.

By studying the electrochemical response at very short times the diffusion can be examined in the first atomic layers of the electrode interface.
Internal Mobilities in Molten Systems (Na-K)NO3 and (K-Cs)NO3
Authors: Yang Chao-cheng , Takagi Ryuzo , Okada Isao
Published: February 2015

Internal mobility ratios in melts of the binary systems (Na-K)NO3 and (K-Cs)NO3 have been measured with the Klemm method in a wide range of concentration and temperature. From these and the available data on densities and conductivities, the internal mobilities have been calculated. In both systems the Chemla effect has been observed at relatively high temperature. The internal mobilities of Na+ and K+ seem to be well expressed by b = [A/(V- V0)] exp(-E/RT) (V: molar volume; V0 , A and E are parameters) in the respective systems (Na-M)NO3 (M = K, Rb and Cs) and (K-M)NO3 (M=Rb and Cs). The internal mobilities in the binary alkali nitrate melts can be qualitatively rationalised in terms of the attraction effect, the free space effect and the agitation effect.
Observation of the Zeeman Effect of Ozone by Doppler Free Laser Spectroscopy
Authors: Schieder R. , Winnewisser G.
Published: February 2015

The Zeeman effect of rotational-vibrational transitions of ozone has been studied with a CO2 laser at 9.6 μm by means of saturation spectroscopy. The observed Zeeman pattern of the ν3 transitions 168.9-168.8 and 119.2-129.3 are analyzed and compared with calculations. The previously proposed assignments are confirmed.
Vapour Pressure Isotope Effects of Chloroform
Authors: Jancsó G. , Jákli Gy. , Fetzer Cs.
Published: February 2015

The vapour pressure difference between CHCl3 and CDCl3 is measured by differential capacitance manometry between -60 and +60 °C. The results can be expressed by the equation ln(pH /pD) = 5.507 × 10-3-6.269/T. The vapour pressure of CHCl3 between -98 and +62°C has also been determined. The experimental H/D vapour pressure isotope effect data together with the available literature values on the 12C/13C and 35C1/37Cl isotope effects are interpreted within the framework of the statistical mechanical theory of isotope effects in condensed systems. The results show that the anharmonicity constant of the CH stretching vibration decreases by about 4% on the vapour-liquid transition.
A Molecular Dynamics Study of the Structure of an Aqueous CsF Solution
Authors: Szász Gy. I. , Heinzinger K.
Published: February 2015

A molecular dynamics simulation of a 2.2 molal aqueous CsF solution has been performed employing the ST2 water model. The basic periodic cube with a sidelength of 18.50 Å contained 200 water molecules, and 8 ions of each kind, corresponding to an experimental density of 1.26 g/cm3. The simulation extended over 6.5 ps with an average temperature of 307 K. The structure of the solution is discussed by means of radial distribution functions and the orientation of the water molecules. The computed hydration numbers in the first shell of Cs+ and F- are 7.9 and 6.8, respectively; the corresponding first hydration shell radii are 3.22 A and 2.64 A, respectively. Values for the hydration shell energies and the heat of solution have been calculated.
Glassy Carbon/KCl-Solution Interface Impedance. Mechanical Surface Treatment Effect
Authors: Mentus S. V.
Published: February 2015

The dependence of complex impedance behaviour on mechanical surface treatment of glassy carbon electrodes in standard water KCl solutions at room temperature was investigated. A considerable frequency dependence of both the real and the imaginary term of the impedance was observed in the entire 1-50 kHz range of frequencies used for electrodes of different surface roughness. The results are discussed in the light of the Levie theory.
Ba, Rb and Cs in the Earth's Mantle
Authors: Hofmann Albrecht W. , White William M.
Published: February 2015

In 166 isotope dilution analyses of Ba, Rb, Cs on fresh basalts from mid-ocean ridges and oceanic islands, Ba/Rb and Cs/Rb ratios are nearly constant. From this, we conclude that Ba/Rb and Cs/Rb ratios are essentially constant in the present-day mantle in spite of large differences in the degree of source depletion or enrichment. As it appears improbable that these ratios could be both constant and non-primitive, we propose that they are representative of the primitive mantle and of the present-day crust-mantle system. We explain this uniformity of relative abundances as follows: the mantle is depleted by subtraction of a mobile phase such as a partial melt or an aqueous fluid. In either case, a significant amount of the mobile phase remains in the residue. Ba, Rb and Cs are among the most highly incompatible elements. Therefore the mobile phase cannot fractionate these elements relative to one another but retains the source ratios of Ba/Rb and Cs/Rb. Also, the amount of mobile phase remaining in the residue is enough to dominate the Ba, Rb and Cs concentrations in the residue. Consequently, neither the mobile phase nor the residue, nor any other portion of the mantle that may be enriched by addition of the mobile phase, will be changed in their relative abundances of Ba, Rb and Cs, even though the absolute abundances of these elements may change by orders of magnitude.

The primitive Ba/Rb = 11.3 and Cs/Rb = 12.6 x 10-3 lead to the following estimates for the primitive mantle: Ba = 6.9 ppm (taken from Jagoutz et al. [1]). Rb = 0.61 ppm and Cs = 7.7 ppb.

Assuming the earth has a chondritic Sr/Ba ratio of 3.08, we calculate a Rb/Sr ratio of 0.029 for the earth. This corresponds to a present-day 87Sr/ 86Sr of 0.7045. This value lies near the lower limit of the ratios estimated from the correlation of Nd and Sr isotopic abundances in oceanic basalts.

The Cs/Rb ratios is about a factor of ten lower than the Cl-chondritic ratio and a factor of three lower than the lunar ratio. This low terrestrial Cs/Rb ratio should be matched by similar values in the continental crust. However, the large range of Cs/Rb ratios found in the crust prevent us from obtaining a meaningful mass balance.
On the Pressure Balance and Plasma Transport in Cylindrical Magnetized Arcs
Authors: Schram D. C. , Mullen I. J. A. M. v. d. , Pots B. F. M. , Timmermans C. J.
Published: February 2015

Magnetized current-carrying plasmas exhibit usually significant E x B rotation velocities which often approach the ion thermal velocity. It is shown both experimentally and theoretically that this rotation in combination with inertia, viscosity and friction leads to an important reduction of the radial transport. If the radial electric field component is directed inward an inwardly directed force on the ions is set up. On the other hand, turbulence leads to enhanced transport especially at higher values of the electron Hall parameter. Also this effect is observed in this experiment and is shown to be in accordance with measured turbulence levels.
On the Approximate Relation Between the Sum of Semiempirical Molecular Orbital Energies and the Total Energy of a Molecule
Authors: Maksić Zvonimir B. , Rupnik Krešimir
Published: February 2015

The Ruedenberg type formula relating the total molecular energy to the sum of orbital energies is examined by using SCC-MO and ab initio DZ MO eigenvalues. Comparison with rigorous ab initio DZ energy expectation values indicates that Ruedenberg’s formula in its original form can not provide semiquantitative information on molecular energetics. Much more promissing in this respect is the electrostatic potential at the nuclei approach of Politzer and Parr.
Untersuchung von Fe90B10-und Fe83B17-Schmelzen mittels Röntgen-Beugung/ X-Ray investigation with Fe90B10- and Fe83B17-melts
Authors: Noid Ernst , Rainer-Harbach Georg , Lamparter Peter , Steeb Siegfried
Published: February 2015

By means of X-ray diffraction the two molten alloys Fe90B10 and Fe83B17 were investigated. The second maximum of the intensity curve shows in both cases a small shoulder which up to now never was observed with binary melts. The interatomic distances and the coordination numbers were evaluated. The normalized atomic distances taken from the pair correlation function of amorphous Fe80B20 agree well with those reported in literature for a tetrahedral model, whereas the normalized distances obtained with the two melts show rather large deviations from this model.
Zur spektroskopischen Analyse von Reaktionen zweiter Ordnung
Authors: Mauser Heinz
Published: February 2015

The following questions are investigated: Is it possible to analyse chemical reactions with spectrophotometric means only, without knowledge of molar absorptivities? What kind of informations are necessary to distinguish between two or more chemical reactions? This investigation is restricted on simple reactions of first and second order. The differential equation is solved for the general case. Difference Equations for the kinetic analysis are expressed. For a number of selected reactions the characteristic parameters are listed. More complicated reactions will be investigated in a following paper.
Thermodynamics of Ion Formation by Fast Dissipation of Energy at Solid Surfaces
Authors: Krueger F. R.
Published: February 2015

A fast dissipation of a certain amount of energy at a solid surface by a mechanism whatsoever may cause a non-equilibrium phase transition of the surface material forming nearly instantaneously a relatively large amount of gaseous molecular and atomic ions. This is known to be a phenomenon common to many techniques utilized to create ions especially from organic solids. The thermodymanics of these processes are deduced from first principles; physical properties (kinetic energy and angular distributions, excitation energy) and chemical properties (ion types, mass spectra and intensities) are derived. Like “temperature” as an intensive quantity plays a major role in equilibrium thermodynamics, “action” as an extensive quantity takes the counterpart in this very far-from-equilibrium behaviour.
Analysis of the ESR Hyperfine Coupling in Mono- and Bicyclic Azine Radical Anions by Means of Calculated Spin Densities
Authors: Palmerand Michael H. , Simpson Isobel
Published: February 2015

Ab initio studies of the spin density in mono- and bicyclic N hetero-aromatic compounds, and naphthalene are reported. The wave functions were constructed from both minimal and double zeta bases in all cases, and both RHF and UHF formalisms were used together with quartet annihilation. The statistical variations in correlations between spin population density and hyperfine coupling are investigated. After annihilation the MB and DZ wave functions become relatively similar, but do lead to some differences in assignment for the smaller values of aH . In general the agreement aH/aN between and calculated density is improved by two term rather than one term expressions, but there are still a number of experimental hyperfine couplings awaited.
Proton NMR Investigations of the Smectic-C Phases of Three Alkyloxy-Azoxybenzenes
Authors: Limmer St. , Findeisen M.
Published: February 2015

Proton NMR investigations of the smectic-C phases of three 4,4′-bis-n-alkyloxy-azoxybenzenes (C7, C8 , C9) with temperature independent tilt angles are presented.

The behaviour of well-aligned samples (strong magnetic field ≳ 1.5 T, slow cooling rate) under rotation in the field can be described by the models of Luz and Meiboom, and Wise, Smith, and Doane, (LM/WSD), resp. However, on polarization of the samples in presence of magnetic fields ≲ 0.75 T the molecular directors are not arranged preferentially parallel to the direction of the polarizing magnetic field but are rather inclined, i.e., the layers are stacked preferentially perpendicular to the original magnetic field direction (PSL model). It is shown that all the angular dependences of NMR second moments can be interpreted in terms of a superposition of the LM/WSD and PSL models, or, on the other hand, by assuming totally disordered fractions of the samples together with portions that fully obey the behaviour demanded by one of the above models (LM/WSD or PSL). The tilt angles derived from the comparison of experimental and theoretical angular dependences of the second moments for well-aligned samples are applied to the explanation of the experiments at lower polarizing fields successfully, too.
Dirichlet and von Neumann Basis Set for Quantum Mechanical Anharmonic Oscillators
Authors: Mesón Alejandro M. , Fernández Francisco M. , Castro Eduardo A.
Published: February 2015

It is shown that accurate upper and lower bounds to the eigenvalues of anharmonic oscillators can be obtained by means of the Rayleigh-Ritz variational method and two trigonometric basis sets of functions which satisfy Dirichlet and Von Neumann boundary conditions. Numerical results show that the Dirichlet basis set is more appropriate than the harmonic oscillator one for calculating eigenvalues and the value of eigenfunctions at the origin.
Reliability Theory of Stochastic Fracture Processes in Sustained Loading: Part I
Authors: Krausz A. S. , Krausz K. , Necsulescu D.
Published: February 2015

It is shown that the physical mechanism of thermally activated subcritical crack growth is always a stochastic process and leads, therefore, to probabilistic crack propagation. This process is the result of the random breaking of atomic bonds and has to be clearly distinguished from the well known Weibull distribution. A Markov chain analysis leads to the normal distribution of crack sizes. The results demonstrate that conventional deterministic finite life-time designs are unsatisfactory and can lead to early failure of machine or structure elements as the consequence of the probabilistic process of crack propagation. The conclusions lead to the reliability analysis of Part II.
An Incomplete-Dissociation Model for Diffusion and Ionic Conduction in Pure Molten Salts
Authors: Klemm A.
Published: February 2015

Diffusion and ionic conduction in pure 1:1 molten salts is described by an incomplete-disso­ciation model comprising neutral diatomic molecules and monoatomic ions. The internal mobility b+- and the self-diffusion coefficients D+ and D- are given in terms of the six inter­particle friction coefficients and the degree of dissociation. By an approximation it is possible to derive from experimental D+ and D- values an apparent degree of dissociation which ranges from 0.93 for NaCl to 0.51 for TlCl and decreases with temperature.
EXAFS Study of Ni2+ Coordination in Nitrate Solutions
Authors: Licheri G. , Pinna G. , Navarra G. , Vlaic G.
Published: February 2015

Four aqueous solutions of Ni(NO3)2 of concentrations ranging from 0.5 M to 4.0 M were examined by the EXAFS technique. The isolation and analysis of of the peak corresponding to the first coordination shell of the metal ion shows that the Ni2+ ion is surrounded by about 6 water molecules at a distance of about 2.06 Å.
Dissociation of 2,4-Dinitrobenzoic Acid and D-10-Camphosulfonic Acid in Water-Methanol Mixtures at 25 °C
Authors: Ritzoulis George , Papadopoulos Nikolaos , Galiatsatos Vasilios , Christodoulou Danae , Jannakoudakis Dimitrios
Published: February 2015

The dissociation constants and the equivalent conductances of 2,4-dinitrobenzoic acid and D-10-camphosulfonic acid have been determined in water-methanol mixtures at 25 °C. The experimental data have been analyzed with the “Fuoss 78” conductance equation. The Bjerrum critical distance was accepted instead of Gurney’s cosphere diameter. Values of KA and Λ0 are reported.
Ion-Acoustic Wave Radiation from a Point Source in a Streaming Magnetoplasma
Authors: Tavzes R. , Čerček M.
Published: February 2015

We report theoretical and experimental results on the radiation pattern of the ion acoustic waves below the ion cyclotron frequency from a small probe in a streaming magnetoplasma. In the fluid approximation with cold ions the ion acoustic resonance cones are found to be drastically changed. Experimental ray velocities and constant phase surfaces are in good agreement with the theoretical results
Löschung der Perylen-Fluoreszenz durch Ag+ -Ionen / Quenching of the Perylene Fluorescence by Ag+-Ions
Authors: Dreeskamp H. , Läufer A. , Zander M.
Published: February 2015

The fluorescence of perylene in fluid solution (λ0.0 = 440 nm) is quenched by silver ions in a dynamic process according to a Stern-Volmer kinetics (kq = 2 · 109 [1 • mol-1 · sec-1], in ethanol at 295 K). Simultaneously an unstructured long-wavelength emission (λmax ≈ 470 nm) appears which we assign to a perylene/Ag+ exciplex. A similar emission is observed when other polvcyclic aromatic compounds (PAC) are used, whose fluorescence as in the case of perylene is not easily quenched in an external heavy atom effect by iodopropane (kq ≦ 106). In these cases the excited PAC/Ag+ complex is long-lived enough to emit fluorescence since the intersystem crossing to the triplet system is slow due to the absence of an energetically favorable accepting triplet state
Die chemische Fixierung von Kryptonisotopen in Zeolith 5 A — Voraussetzung für die Messung von 25 keV Neutroneneinfang- querschnitten mit der Aktivierungstechnik/ The Chemical Fixation of Kr Isotopes in Zeolite 5 A.- Prerequisite for the Determination of 25 keV Neutron Capture Cross Sections with the Activation Method
Authors: Penzhorn R.-D. , Walter G. , Beer H.
Published: February 2015

By chemical fixation of Kr in zeolite 5 A adequate samples can be obtained to determine the capture cross section of reactions such as 84 Kr (n, γ) 85Krm and 86Kr (n, γ) 87Kr. The employed zeolite loading was of the order 52-66 [cm3 STP Kr/g zeolite]. The capture cross section of the reaction 84Kr(n, γ) 85Krm was determined at thermal and 25 keV neutron energy. The value obtained at 25 keV is of relevance to the stellar nucleosynthesis of heavy elements.
Reliability Theory of Stochastic Fracture Processes in Sustained Loading: Part II, Stochastic Loading
Authors: Necsulescu D. , Krausz A. S. , Krausz K.
Published: February 2015

A Markovian model of crack growth was presented in the first part of the paper. The present Part II presents a model for the case of random load, in order to obtain the probability distribution of the resulting crack size. A general model and the particular cases of a uniformly distributed stress intensity factor and mechanical work, are presented. This model separates the factors producing the crack growth in a homogeneous material from those considered in the Weibull model for nonhomogeneous materials.
Vibrational Spectra and Force Constants of Symmetric Tops, XXXIII. Rovibrational Analysis of ν6 ,2ν6
0 and 2ν6
±
2of H3
74GeI
Authors: Bürger H. , Eujen R. , Rahner A. , Schulz P. , Drake J. E. , Cradock S.
Published: February 2015

The infrared spectrum of monoisotopic H3
74GeI has been investigated with a resolution of 0.04 cm-1 in the region of ν6 and 2ν6 . Rotational analyses (σ(J, K)~7 · 10-3 cm-1) of ν6 , 546.117(3), 2ν6±2 , 1094.731(4), and 2ν6
0, 1091.530(4) cm-1 , have been performed, and vibrational and rotational parameters of the apparently unperturbed υ6 = 1 and 2 states have been obtained. Q branches of hot bands with ν3 and ν6 as lower states have been detected, and the anharmonicity constants X36 , X66 and g66 have been determined. The simultaneous analysis of ν6±1 , 2ν6±2 and 2ν6±2 - ν6±1 provides an improved A0 value.
35Cl Nuclear Quadrupole Interaction in Thionyl Chloride
Authors: Mata Fernando , Carballo Norberto
Published: February 2015

21 hyperfine multiplets, up to J = 12, have been measured for thionyl chloride (32S16O35Cl2), by means of microwave spectroscopy in the region 18.0 -26.5 GHz. Nuclear quadrupole coupling constants along the principal axes of inertia were determined to be χaa = - 25.004 ± 0.040 MHz, χbb = -0.009 ± 0.025 MHz and χcc = 25.013 ± 0.031 MHz. Also, coupling constants along the S-Cl bond axis (z axis) and two axes perpendicular to this have been calculated to be χxx = 65.93 MHz, /χyy = 30.36 MHz and χzz = -96.30 MHz. These values have been compared with those of other workers and with those of other related molecules. Information about the electronic distribution in the S-Cl bond has been obtained from the values of these constants, and the results have been discussed.
Notizen: Raman-Spektroskopische Untersuchungen der Systeme ASCl3/Cl2-AlCl3 und AsCl3 /Cl2-GaCl3/ Raman Spectra of the Systems AsCl3/Cl2—AlCl3 and AsCl3/Cl2-GaCl3
Authors: Demircan B. , Brockner W.
Published: February 2015

In the systems investigated only the compounds AsAlCl8 and AsGaCl8 g are found. Raman spectra were recorded for the solid and molten compounds and for mixtures with excess ASCl3 + CL2 and AlCl3 and GaCl3 , respectively. The observed frequencies are assigned to tetrahedral AsCl4
+, AlCl4
- and GaCl4
- units. Melting of AsCl4AlCl 4 and AsCl4GaCl4 causes a decomposition into AsCl3 , Cl2 and AlCl3 and GaCl3 , respectively.
Theory of Fluorescence Depolarization by Anisotropic Brownian Rotations
Authors: Alicki Robert , Alicka Maria
Published: February 2015

On the basis of a generalized diffusion equation for the rotational motion of an asymmetric rigid rotor a general expression for steady-state fluorescence depolarization has been obtained.
Der Einfluß der Spin-Kopplung auf die ESR-Spektren der Orthochromite YCrO3 und LuCrO3 / The Influence of Spin-coupling on the ESR-spectra of the Orthochromites YCrO3 and LuCrO3
Authors: Dräger K.
Published: February 2015

Polycrystalline samples of stoichiometric YCrO3 and LuCrO3 were investigated by ESR in the temperature range between 140 K and 520 K. Although the orthochromites have a complicated spin structure, the line width shows the temperature dependence of simple antiferromagnetic systems. Up to a high degree the spectra have a Lorentzian line shape. The ESR intensity confirms the predictions of a cluster model. The coupling energy describing the gap between the bounded and the resonance state was found to be ⊿E = 250 cm-1 for YCrO3 and ⊿E = 210 cm-1 for LuCrO3 . There is a distinct relation between the excitation energy ⊿E and the volume V of the elementary cell. Further calculations concerning the isotropic exchange interaction result in a coupling constant of J = 5.55 cm-1 for YCrO3 and J = 4.67 cm-1 for LuCrO3.
An ab Initio SCF Study on the Stability and Structure of H2CN+ · nN2 Clusters
Authors: Ha Tae-Kyu , Nguyen Minh Tho
Published: February 2015

The clustering energies and geometries of the H2CN+ · nN2 (n = 1, 2 and 3) species have been determined by ab initio SCF calculations with the 4-31G basis set. The calculated clustering energies are in good agreement with the experimentally estimated heats of formation of the cor-responding clusters. The stability of various conformers has been studied in terms of localized orbitals and charge distributions.
Spontaneous Tunnel Transitions Induced by Redistribution of Trapped Electrons over Impurity Centers
Authors: Berezin A. A.
Published: February 2015

A system of polyvalent impurity centers in a semiconductor (i.e. Au-centers in Si) is con-sidered. The ground state of the impurity pair Au-(a) + Au° (b), where an extra electron is localized on the site a, may be turned into an excited state due to a change of the charge state of a third nearby impurity site. This happens because of different shifts of the Au--level at sites a and b due to their different distances from the third center. As a result, the original pair is able to reach a new ground state Au° (a) + Au- (b) through a slow spontaneous tunnel transition. The probability of this transition, when it is accompanied by an emission of a low energy photon, is calculated explicitly.
A Four-Level Double Resonance Experiment on HCCC15N with a Bridge Type Superheterodyne Microwave Spectrometer
Authors: Bomsdorf H. , Dreizler H.
Published: February 2015

A four-level double resonance method has been developed allowing the determination of the relative collision induced change in signal intensity rj without application of the Stark modula-tion technique. The method is based on certain properties of the bridge type superheterodyne spectrometer and may be applied to molecular transitions showing strong microwave absorption, η-values have been determined for various four-level systems consisting of |M| -resolved rotational levels of the linear molecule HCCC15N. In addition to the measurements on the pure substance the influence of foreign gas admixtures with H2 , He, Ne and Ar on the results has been investigated.
Appearance Energies and Calculated Partial Mass Spectra of (23-), (2,4-) and (2,5-)Dimethylaniline Isomers
Authors: El-Kader F. H. Abd , Ahmed H. M.
Published: February 2015

The ionization and appearance energies for the molecular and fragment ions, respectively, of the three dimethylaniline isomers are reported. Breakdown graphs have been constructed expressing the energy dependence of the fragmentation of the isomeric molecular ions covering the internal energy range from threshold to approximately 10 eV. The kinetic shift and the critical energy for the fragments (M-H)+ and (M-CH3)+ ions are also calculated.
Microwave Diagnostic of the Pulsed Plasma Generation in the Hollow-Cathode Glow Discharge
Authors: Hildebrandt J.
Published: February 2015

The radius and speed of the cylindric ionization front that expands during the application of a high-voltage pulse upon a double-plate hollow-cathode, is measured by reflection of 8 mm-microwaves.

By comparing the number of transported electrons and their ionizing action, ionization by single electron collisions is shown to be impossible.

In the "normal regime" below a certain voltage threshold, a pulse height variation has only an influence on the final plasma radius but not on the local speed of the cut-off surface during recombination.
A Reinvestigation of the Rotational Spectrum of 2-Chloropropene
Authors: Fliege E. , Dreizler H.
Published: February 2015

The microwave spectrum of 2-chloropropene was reinvestigated using microwave Fourier transform spectroscopy. For the two isotopic species CH3C35Cl=CH2 and CH3C37Cl=CH2 the chlorine quadrupole coupling was determined with higher accuracy. The barrier to internal rotation was determined from the ground state. For comparison the first excited torsional state of CH3C35Cl=CH2 was remeasured and reanalysed
On Energy Differences in Many Body Systems
Authors: Müller Eberhard. E. , Feist Wolfgang
Published: February 2015

Number-and operator-valued energy differences in von Neumann algebras are discussed by means of the Tomita-Takesaki theory. Small energy differences can be evaluated by the anti-commutator of a sort of relative entropy operator and the energy operator. The New-Tamm-Dancoff procedure is studied in terms of the standard form.
Enthalpies of Mixing for Binary Liquid Mixtures of Acids
Authors: Haase R. , Jansen H.-J. , Winter B.
Published: February 2015

For the binary liquid systems formic acid + acetic acid, formic acid + propionic acid, and acetic acid + propionic acid, we give the results of new calorimetric measurements of the molar excess enthalpy H̄E at 25 °C, 30 °C, 40 °C, and 60°C, covering the entire range of compositions. H̄E is always positive, increases linearly with the temperature, and is slightly asymmetric with respect to the mole fraction x. The composition at the maximum of the function H̄E(x) is independent of the temperature.
Relaxation of Electrons in the Boundary Layer of a Weakly Ionized Plasma
Authors: Schumacher A.
Published: February 2015

We study the kinetics of fast electrons in a weakly ionized collision dominated plasma in front of a planar negative wall. For small Debye lengths the potential variation in the boundary layer can be approximated by a potential jump representing the space charge sheath. We propose an approximation method to calculate the electron distribution function which accounts for general boundary conditions (absorption, reflection and emission). This method is based on a parametrization of the angular dependency, the unknown parameters being determined by a suitable adaption of the Method of Weighted Residuals. The error inherent in our approximation procedure is discussed and shown to be small. As result we get a straightforward analytic representation of the electron distribution function in the boundary layer. For the special case of a totally absorbing wall our results are in good agreement with exact analytical solutions in the literature.
Comments on “A Geometrical Correction for Precise Lattice Constant Determination” by Bradaczek, Leps, and Uebach
Authors: Berger Hans
Published: February 2015

The expression for diffracted X-ray intensity as a function of absorption and asymmetry derived by Bradaczek et al. [1] is already contained in the general integrated-intensity formula. It is interpreted incorrectly by these authors with regard to the correction of precision lattice constants.
Proton and Fluorine Spin-Lattice Relaxation in Polycrystalline CoSiF6 · 6 H20
Authors: Rager H.
Published: February 2015

The spin-lattice relaxation times T1 (1H) and T1 (19F) in CoSiF6 · 6H20 have been measured at 30 MHz in the temperature range 150 K ≦ F ≦ 400 K Both T1 (1H) and T1 (19F) decrease sharply at the phase transition temperature of 246 K (cooling cycle). The main relaxation mechanism is assumed to be an Orbach process. From the T1 data an average splitting of the Co2+ ground state of about 400 cm-1 in both phases is obtained. The splitting is mainly caused by spin orbital coupling.
Borel Summation Method and First Order Perturbation Formula for the Potential V (r)=F/r2+G/r+H/{r+z2)
Authors: Choudhury R. K. Roy , Ghosh Barnana
Published: February 2015

The Borel Summation Method is applied to obtain a first order formula for the bound states for the potential V(r) = F/r2 + G/r + H/(r + z2). For small H our formula reproduces the numerical results given by Znojil.
Study by Numerical Simulation of the Structural and Dynamical Properties of the Fused LiCl-KCl Eutectic
Authors: Lantelme F. , Turq P.
Published: February 2015

The ionic properties of the eutectic LiCl-KCl melt are examined in a large range of temperature and density. The radial distribution functions are calculated. It is shown that, although the contribution of the Coulomb energy to the thermodynamic properties decreases at high temperatures it remains always predominant and explains the temperature dependence of the specific heat at constant volume.

The diffusion coefficients of Li+, K+ and Cl- are determined. The mechanism of the ionic motion is studied through the memory function formalism. Two types of motion are detected, which arise from binary collisions and from dynamical events which involve a large number of ions. Temperature and volume changes show that the lithium ions remain always surrounded by a more structured atmosphere which hinders their motion. This effect becomes more apparent at high temperature and low density.
Knight Shift in the V3Ga Compound at High Temperatures
Authors: Rünger R. , Ploumbidis D.
Published: February 2015

The temperature dependence of the Knight shift of both 51V and 71Ga in the V3Ga compound has been measured over the entire range from 300 K to 1300 K. The results are discussed using a model based on the assumption that the core polarization contribution to the total Knight shift is the temperature dependent term.
A Microscopic Study of Motions in Supercooled 1,3-Butanediol
Authors: Soltwisch M. , Schneider F. , Quitmann D.
Published: February 2015

Quasielastic Rayleigh scattering of 14.4 keV Mössbauer γ-radiation has been measured on 1,3-butanediol, yielding the width Γ of the central line (assumed to be Lorentzian) and its relative intensity, for momentum transfers corresponding to molecular dimensions (k = 0.9... 2.5 Å-1) at 243 K. Γ (k) rises fast and then saturates. An effective correlation time τ and jump width is derived characterizing the diffusional motion of individual molecules considered as entities. Fast motions (vibrations, librations) are taken into account explicitly. The correlation time τ compares well with results from other experiments. The temperature dependence was followed from 208 up to 263 K.
The Liquid Crystal Region in Cesium Soaps
Authors: Sanesi Manlio , Franzosini Paolo
Published: February 2015

The temperatures and enthalpy changes pertinent to the fusion and clearing processes in the linear cesium alkanoates from tridecanoate to eicosanoate were measured by differential scanning calorimetry. The present information along with data previously taken on the lower homologs allows one to draw the boundaries of the region where cesium soaps can exist in the liquid crystal state.
Semiempirische Untersuchungen zur Lösungsmittelabhängigkeit der SE-Reaktivität des Benzol [1.3]dioxols / Semiempirical Calculations on the Solvent Dependence of the SE–reactivity of Benzo[1,3]dioxole
Authors: Raabe Gerhard , Fleischhauer Jörg
Published: February 2015

The highly regiospecific electrophilic substitution of Benzo[1,3]dioxole leads only to the β-substitution products. Quantumchemical calculations with the semiempirical MNDO- and MINDO/3-methods including the influence of the solvent however suggest that there might be a critical value of the dielectric constant of the solvent above which the α-σ-complex formed by the attack of an electrophil (H+ or Cl+) should be energetically more favoured than the corresponding β-σ-complex.
Determination of the Stability of the AIO+ Complex in Alkali Halide Melts*
Authors: Wai C. M. , Blander M.
Published: February 2015

The solubilities of Al18
2O3 in LiCl-KCl eutectic mixtures containing dissolved AlCl3 were measured using a sensitive proton activation technique. The results are consistent with the presence of an A10+ species at 4.7 x 10-5 mole fraction with AlCl3 at 10-2 mole fraction. When combined with other thermodynamic data, these solubilities are used to deduce a formation constant for the A10+ species from Al3+ and O2- ions of 1.94 x 1022 (in mole fraction units) and a specific bond free energy ("bond strength") of 300 kJ mol-1
Untersuchungen mit Hilfe der Elektronenzyklotronresonanz-(ECR)-Technik XVI .Wechselwirkung von HNO3 und CINO3 mit niederenergetischen Elektronen in der Gasphase / Studies by the Electron Cyclotron Resonance-(ECR)-Technique. XVI. Interactions of Thermal- Energy Electrons with the Molecules HNO3 and CINO3
Authors: Wecker D. , Schindler R. N.
Published: February 2015

Using the ECR-technique the capture of thermal-energy free electrons was investigated by the molecules HNO3 and ClNO3. The following rate constants at room temperature were obtained:

k(HNO3) =(1.4 ±0.7)· 10-8 cm3 sec-1 ;

k (ClNO3) = (3.9 ± 1.2)· 10-9 cm3 sec-1 .

An apparent activation energy of AE = (1.6 ± 0.5) kcal · mol-1 was found for the reaction with ClNO3.

From the energy dependences of the both reactions together with thermodynamic considerations it is suggested that electron capture by ClNO3 occurs via dissociative attachment whereas with HNO3 a negative parent ion can be formed. Strong similarity is pointed out to exist between HONO2 and ClONO2 towards capture of electrons and the reaction with O2
- respectively.
A Pulsed Proton Magnetic Resonance Study of Some Organic Compounds
Authors: Köksal Fevzi , Bahçeli Semiha
Published: February 2015

Spin-lattice relaxation times (T1) of protons in polycrystalline dimethyl sulfone, stearic acid, stearyl alcohol, trimethylamine-N-oxide, tertiary-butylhydrazine hydrochloride and tertiary-butyl carbamate have been measured over a range of temperatures by pulsed proton magnetic resonance. Except for tertiary-butyl carbamate a single minimum in T1 was observed for all the compounds. The T1 results have been interpreted by considering the methyl group reorientations about the C3 axis and the role of the spin diffusion of the other protons to the methyl protons in the compounds. The double minima in T1 for tertiary-butyl carbamate have been attributed to reorientations of methyl groups in the tertiary-butyl group about the C3′ axis and reorientations of each methyl group about its C3 axis. The spin-lattice relaxation parameters have been determined.
Resistometric Evidence of Diffusional Mixing in Concentration Layered Amorphous AgCu Films
Authors: Reda I. M. , Wagendristel A. , Bangert H.
Published: February 2015

In order to separate diffusion induced changes in the electrical resistivity of quench-condensed amorphous AgCu alloy films from such arising from other causes several trial experiments have been performed. Such films consisting of alternating Ag60Cu40/Ag40Cu60 layers showed a specific resistance rise which revealed the following peculiarities:

1. The duration of this increase is inversly proportional to the square of the individual Ag60Cu40/Ag40Cu60 couple thickness,

2. The increase is suppressed if rapid heating up to the crystallization temperature is performed and

3. It is not appearing in homogeneous layers.

These results give clear evidence that the observed effect is arising from diffusional intermixing only. Diffusion coefficients averaged over the annealing period are estimated as D = 8.7 x 10-15 cm2s-1 x exp 0.89 eV/kT.
Ab Initio-Rechnungen zur Protonenaffinität unverzweigter primärer aliphatischer Amine / Ab Initio-Calculations on the Protonaffinity of Unbranched Primary Aliphatic Amines
Authors: Heyne Eberhard , Raabe Gerhard , Fleischhauer Jörg
Published: February 2015

Recently we reported the results of semiempirical calculations (MNDO, MINDO/3) which led us to the conclusion, that the proton-affinity of molecules R-NH2 (R = H, CH3, C2H5, n-C3H7 and n-C4H9) is determined by the ability of the groups R to carry positive charge in the corresponding cations R-NH3
+.

We did extend our investigations concerning the protonaffinities of primary aliphatic amines including NH3 and performed ab initio calculations with an STO-3G basis. The results qualitatively parallel those obtained by the semiempirical methods mentioned above.

In contrast to the semiempirical results we found that there is a satisfactory correlation between the Mulliken-charges of the nitrogen-atoms and of the NH2-groups and the experimental protonaffinities if NH3 is excluded.
Concentration Fluctuations in Liquid Sodium-Caesium Alloys
Authors: Gallego L. J. , Alonso J. A.
Published: February 2015

The non-random two-liquid (NRTL) theory developed by Renon and Prausnitz has been used to calculate the concentration fluctuations in liquid Na-Cs alloys. The agreement with experiment is better than with other theories used previously.
Magnetization Measurements on Iron (III)Solutions for Detecting Oligomer Formation
Authors: Rodríguez F. , Moreno M. , Sal J. C. Gómez
Published: February 2015

By measuring the magnetization at low temperatures (near 1 K) and intense magnetic fields ( ≳100 KG), information about oligomer formation in ferric salts solutions can be obtained. It is shown that, under rather general conditions, the magnetic moment per ferric ion of a given ferric solution measured in the saturation regime should be equal to 5 β if all the complexes involved in the solution are high-spin monomers. Moreover, if the solution is mainly composed by monomeric species and antiferromagnetic dimers, the relative concentration of monomeric and dimeric species can easily be determined. This techniques has been applied to solutions of Cl3Fe and (NO3)3Fe9H2O in isopropanol as solvent containing about 0.4 M of water. In the first case the present measurements are consistent with the existence of dihydroxo ferric dimers suggested by previous Mössbauer and Optical Absorption data. The relative concentration of these dimers increases from 25% to 50% when the water content increases from 0.4 M to ~ 10 M. In the second case it is confirmed that the solution is mainly composed by oligomers, the relative concentration of monomeric species being less than 30%.
Elementary Derivation of the Dirac Equation. VI
Authors: Sallhofer Hans
Published: February 2015

The transversality in the electrodynamic hydrogen field is discussed.
Relativistische Verallgemeinerung des Lenzschen Vektors (I) / Relativistic generalisation of the Lenz vector (I)
Authors: Kern Eberhard
Published: February 2015

The non-relativistic motion of a particle in a central field with 1/r potential, e.g. the motion of an electron in the Coulomb field of a charged nucleus at rest, is described by the equation of motion (non-relativistic Kepler problem) m x″ = α · x /r3 with α = ez e (product of the charges of the central body ez and the electron e). From this equation of motion, three statements of conservation can be derived: in respect of the energy E, of the angular momentum L and of the Lenz vector Λ = m {x′× L + α ·x/r}. The geometric meaning of Λ is that of a vector pointing in the direction of the perihelion of the particle orbits (conic sections).

It will be demonstrated that also at the relativistic Kepler problem, which is based on the equation of motion

an analogous Lenz vector exists. It represents a quantity of conservation - in the same way as the relativistic energy and the relativistic angular momentum. For the transitional case → ∞, where the relativistic problem turns into the non-relativistic problem, the relativistic Lenz vector also turns into the non-relativistic Lenz vector. The generalised (relativistic) Lenz vector has also a geometric meaning. Its direction coincides with the oriented axis of symmetry of the orbits (rosettes, spirals, hyperbola-type curves etc.).

The quantity of conservation Λ occupies a special position in respect of the quantities of conservation energy and angular momentum. Whereas the energy and the angular momentum correspond with a symmetry of time and space, the Lenz quantity of conservation corresponds with a symmetry of the orbits. The fact that the Lenz vector can relativistically be generalised touches thereby on principal aspects.
The Internal Mobilities of the Molten Binary System (Rb-Cs)NO3
Authors: Takagi Ryuzo , Kawamura Kazutaka , Okada Isao
Published: February 2015

Internal mobility ratios in the molten binary system (Rb-Cs)NO3 have been measured with the Klemm method. From these and the available data on the densities and conductivities, the internal mobilities of Rb+ and Cs+ have been calculated. Above (below) 420 °C, Cs+ is found to be more (less) mobile than Rb+. The internal mobilities of these ions in various binary alkali nitrates are compared.