bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Bound States on the Electrical Conductivity of a Partially Ionized Plasma (Born Approximation)
Authors: Röpke G. 
Published: May 2007

AbstractThe partially ionized plasma is described by a model Hamiltonian containing bound (localized) as well as orthogonalized free (itinerant) electron states. The equations of balance for the single particle states are given, and the correlation functions arising in the equations of balance are treatet in the Born approximation. The conductivity is obtained with the aid of the Kohler variational principle. The electron density dependence of the conductivity is presented for different values of the bound state energy level and of the temperature.
On the Summation of Non‐leading Logarithms in QCD
Authors: Dorn H. , Otto H. ‐J. , Wieczorek E. 
Published: May 2007

AbstractExploiting the relations between the expansion coefficients of Green's functions and those of β and γ functions in massless QFT, the summation up to the n‐th non‐leading logarithms is reduced to the solution of a system of linear differential equations, which in general differ from renormalization group equations. Applying this procedure to the gluon propagator the leading log approximation is modified near the mass shell by a constant factor only. Furthermore for the gluon propagator exponentiation in terms of the running coupling constant is argued to be restricted to leading logarithms.
Impact of the Vibrationally Excited States on the Macroscopic Behaviour of the Band‐like Electron Beam Discharge Plasma in H/H2‐Mixture
Authors: Winkler R. , Wilhelm J. , Krasheninnikov S. I. , Starykh V. V. 
Published: May 2007

AbstractThe investigation of the impact of the vibrationally excited molecules in the electronic ground state was performed by simultaneously solving a balance equation system for the main charge carriers, the H atoms, the metastable H atoms, the H2 molecules in the different vibrational states and for the power transfer of the electrons in the beam discharge mixture plasma. The balance equations for the vibrational states include in particular one‐quantum step excitation and deexcitation, electronic excitation, dissociation and ionization from each vibrational level in electron collisions as well as the finite life time of these states because of the gas transfer through the band‐like plasma. A main finding is that due to the additional impact of vibrationally excited molecules there is a marked enhancement of the resulting dissociation and ionization degree in the beam discharge plasma at medium power input from the turbulent electric field. For discharge parameters of practical interest the ionization and dissociation budget, the population of the vibrational states, the different energy dissipation processes and the energy pumping into the ladder of the vibrational states were calculated and discussed in detail.
Eine neue Methode zur Bestimmung der Rauhigkeitsautokorrelationsfunktion von optischen Oberflächen
Authors: Ponath H. ‐E. , Walther H. ‐G. 
Published: May 2007

AbstractAusgehend von einer allgemeinen Streulichttheorie wird ein Meßverfahren zur Bestimmung der Autokorrelationsfunktion von polierten Oberflächen hergeleitet. Dabei wird die Streulichtintensität in einer bestimmten Richtung in Abhängigkeit von der Streufleckgröße gemessen. Das Meßverfahren wird an einer Glasoberfläche mit unterschiedlicher Politur getestet.
The Impact of Direct Ionization by Beam Electrons on the Electron Kinetics of the Beam Discharge Plasma in Molecular Hydrogen
Authors: Winkler R. , Wilhelm J. , Krasheninnikov S. I. 
Published: May 2007

AbstractIn a recent paper the stationary beam plasma discharge in partially dissociated hydrogen was investigated where the electron component was described by the Boltzmann equation for a mixture of atomic and molecular hydrogen and the main heavy charged and neutral particles by balance equations. It was assumed that, via the quasilinear beam plasma interaction, the electron beam produces only the turbulent electric field whilst an additional production of plasma electrons due to direct ionization by the beam and thus a direct influence on the balances of charge carriers were neglected. Now the additional production of plasma electrons due to direct ionization by the beam is studied on the basis of a generalized Boltzmann equation but for the simpler model of a purely molecular hydrogen plasma. For experimentally obtainable values of the turbulence energy density, beam energy, beam ionization degree and electron life time the calculation of the electron energy distribution function and of the direct beam contribution to the electron particle balance shows a marked influence of the direct beam ionization with increasing degree of beam ionization.
K‐ and L‐Vacancy Production in Asymmetric 1 MeV/N Collisions of Cu and Nb Projectiles with Au and Pb Targets
Authors: Frank W. , Jaracz P. , Kaun K.‐H. , Rüdiger J. , Stachura Z. , Warczak A. 
Published: May 2007

AbstractThe impact parameter dependence of the 3dσ ionization has been measured for CuAu and NbAu collisions. The impact parameter and energy dependence of the K‐L vacancy sharing is discussed in terms of the DEMKOV‐MEYERHOF and NIKITIN models. The total cross sections for producing 3dσ vacancies in all the four collision systems are considered.
Über das Äquivalenzprinzip in der Wellenmechanik
Authors: Treder H.‐J. 
Published: May 2007

AbstractWir zeigen die Gültigkeit der Galilei‐Einsteinschen Prinzipien der Äquivalenz von Trägheit und Schwere in der Wellenmechanik an Hand einer Diskussion der Einsteinschen Gedanken‐Experimente.
Kovariante Quantisierung skalarer Felder im Gravitationsfeld
Authors: Kreisel Eckhard 
Published: May 2007

AbstractZur Ankopplung der Gravitation an die Quantenfeldtheorie werden ortsabhängige unitäre Transformationen betrachtet und Ableitungen eingeführt, die eine nichtintegrale Transportvorschrift für Hilbertraumzustände implizieren. Die mit den verallgemeinerten kovarianten Ableitungen gebildete Klein‐Gordon‐Gleichung für skalare Feldoperatoren läßt sich dadurch im vorgegebenen Gravitationsfeld in gleicher Weise wie die Klein‐Gordon‐Gleichung im Minkowski‐Raum quantisieren; die Zustandsvektoren werden wegabhängig. Die Gleichungen sind bildkovariant, d. h. sie haben in jedem Bild dieselbe äußere Gestalt, speziell im Heisenberg und Schrödingerbild.
Second Order Lagrangian and Angular Momentum of Scalar Field
Authors: Günther H. 
Published: May 2007

AbstractThe class of second order Lagrangian for the scalar field is including free divergence terms giving rise to new canonical conservation laws by means of Noethers theorem. The appearance of a spin like tensor S within angular momentum is nothing but a redefinition of orbital angular momentum. S is mainly giving a new definition of center of mass for the field, indicating that the variation for the motion of singularities is nothing but a redefinition for the motion, since the sum for the additional forces, coming from divergence part of Lagrangian, is zero. Thus, the physical content of the theory will not be affected by the divergence part of Lagrangian, is zero. Thus, the physical content of the theory will not be affected by the divergence termes; it is only an other formulation.
Effective Flavor‐changing Weak Neutral Current in the Standard Theory and Z‐Boson Decay
Authors: Mann G. , Riemann T. 
Published: May 2007

AbstractWe have studied the effective Zf1f2‐vertex in the Glashow‐Salam‐Weinberg theory arising from 1‐loop corrections, allowing for arbitrary fermion masses mi in the loop. We use our results to study the branching ratio of the Z‐boson decay into two different fermions.This is of phenomenological interest if there exist yet unknown fermions with large mass which could show up at present and designed accelerators only through radiative corrections.
Das Zweikörperproblem in der quantisierten, trägheitsfreien Mechanik
Authors: Kreisel E. 
Published: May 2007

AbstractEs existieren keine gebundenen Zustände des Zweiteilchensystems in der Riemann‐Machschen Quantenmechanik. Das Energie‐Spektrum ist notwendig positiv semidefinit und kontinuierlich, in Analogie zum freien Teilchen der Quantenmechanik.
Kinetic Approach to the Electrical Conductivity in a Partially Ionized Hydrogen Plasma
Authors: Schlanges M. , Kremp D. , Keuer H. 
Published: May 2007

AbstractThe electrical conductivity is investigated for a partially ionized hydrogen plasma, starting from a generalized quantum kinetic equation with three particle collision integrals. To take into account plasma effects, screened potentials are used. The transport cross sections of the considered two and three particle scattering processes are calculated by perturbative solution of the Lippmann‐Schwinger equations for the T‐matrices up to the second Born approximation. In connection with a mass action law the influence of the electron‐electron and the elastic electron‐atom scattering is discussed. The pressure ionization (Mott‐effect) is described by a minimum‐behaviour of the electrical conductivity.
Mass Scales and the Cosmological Coincidences
Authors: Landsberg P. T. 
Published: May 2007

AbstractTheories involving the parameters h, c, G, H (in a usual notation) are considered. A huge ratio of 10120 of the mass of the universe (mu) to the smallest determinable mass m0 in the period since the big bang occurs in such theories. Five masses are here identified and interpreted between these two limits so that one has in all seven analytical expressions for masses. They form a geometrical progression m0, m0R, …, m0R6 = mu with R ≈ 1020. It is shown that this formulation is easily adapted to explain existing cosmological coincidences and to generate new ones.
On a Temporal‐Spatial Radiation Functional and its Measurement
Authors: Gase R. , Ponath H.‐E. , Schubert M. 
Published: May 2007

AbstractA so‐called radiation functional of the electric field‐strength is introduced depending on time and space and on the temporal and spatial frequencies, which is applicable to the most general forms of radiation (e.g. non‐stationary, inhomogeneous, partially coherent). The time‐dependent spectrum and the specific intensity of radiation can be deduced as special forms of the radiation functional. The dispersion relations are incorporated.The measurement of the radiation functional by means of a linear optical system followed by square‐law detectors is dealt with; for quasi‐stationary and quasi‐homogeneous radiation the measurable function is proportional to the radiation functional. The propagation of the radiation functional in space is investigated, and, as a simple example, the diffraction by a grating of nonstationary radiation is dealt with.
Symmetry Violation Caused by the Boundary Conditions for Finite Nuclei
Authors: Rotter I. 
Published: May 2007

AbstractThe boundary condition of a finite lifetime of most states of real nuclei as well as its influence on the symmetry properties of the nuclear forces are investigated. It is shown that this boundary condition for finite nuclei induces some symmetry violation, e.g. for the Migdal parameter g', which does not exist in nuclear matter.
On the Theory of Spontaneous Emission by a Single Atom Located in an Ideal Cavity
Authors: Paul H. 
Published: May 2007

AbstractWith the help of the well‐known eigenfunctions for a two‐level system coupled to a single mode of the radiation field, the correlation functions for both the atomic dipole and the electric field oscillation are calculated, in rotating‐wave approximation, for an atom emitting spontaneously into an ideal cavity. Using the Eberly‐Wódkiewicz formalism, the corresponding spectra are evaluated in the long‐time, narrow‐band detection limit. The two spectra exhibit the same Rabi splitting, but the ratio of the strengths of the two lines is significantly different, in the off‐resonance case, for the dipole and the field oscillation.
Zu Newtons Erde‐Mond‐Test von 1665/66
Authors: Richter G. 
Published: May 2007

AbstractNewtons Erde‐Mond‐Test zur Frage, ob die Schwerkraft der Erde, welche frei fallenden Körpern nahe der Erdoberfläche eine Beschleunigung von g ≈ 982 cm sec−2 erteilt, bei Annahme ihrer Abschwächung mit dem inversen Quadrat der Entfernung vom Erdmittelpunkt die beim Umlauf des Mondes um die Erde entstehende Zentrifugalkraft exakt kompensiert, wird im folgenden mit neueren Beobachtungsdaten über g, die Erddimensionen sowie die astronomischen Konstanten der Mondbahn erneut diskutiert.Bei Berücksichtigung der Störung der Mondbewegung durch die Sonne ergibt sich bereits in erster Näherung, daß das Verhältnis der Massen von Mond und Erde nahe bei 1:81 liegen muß, wenn als „mittlere Mondentfernung”︁ der konventionelle Wert 384400 km zugrunde gelegt wird.
On the Kinetic Description of Condensation in Binary Vapours
Authors: Schmelzer J. , Schweitzer F. 
Published: May 2007

AbstractBased on a thermodynamic analysis and an earlier developed general growth equation for clusters of a new phase, the kinetics of growth of droplets in a binary gaseous mixture under isothermal and isobaric conditions is described. Differential equations for the time development of the mean radius of the droplets, the number of droplets, and the overall mass concentrated in the droplets are obtained. These equations describe the evolution of the system of droplets beginning after the nucleation period has finished. The equations can be easily solved numerically. For long times analytic solutions are derived. It is shown that the growth of droplets proceeds accordingly to the mechanism of Ostwald ripening.
Quantum Field Theoretic Treatment of the Casimir Effect at T > 0. Real Time Formalism — Free Field Approximation
Authors: Scharnhorst K. , Robaschik D. , Wieczorek E. 
Published: May 2007

AbstractThe framework of real time quantum field theory at finite temperature is generalized to include boundary conditions for the electromagnetic field strength tensor. In the perturbation theory the usual Feynman rules remain, only the photon propagator is modified. As a first application the Casimir effect is studied in the free field approximation and the known results are rederived with the new method.
Principles of Quaternionic Vacuum Thermodynamics and a Unified Gravistrong Interaction Model
Authors: Scheurich H. 
Published: May 2007

AbstractThe conceptions of the preceding paper [1] are completed by the discussion of first outlines of quaternionically originated vacuum thermodynamics. Thereby the algebraic Planck scale discontinuum statistically and approximately is extended by steps to affinely unconnected and to affinely connected Riemannian spacetime continuum. There results the concept of an irreversible particle realization process out of vacuum, as well as a vacuum foundation of the gauge principle and of the long‐range coupling constants. The version of the Electroweak Standard Model derived from the simple‐regularSO(3,3) representations is extended to a unified interaction model of gravitation and strong forces (gravistrong interaction model) derived from the double‐regularSO(3,3) representations. AnSO(3,3)‐originated connection between the linear graviton field and the non‐linear gravitation field is proposed.
On Internucleon Interaction of Composite Nucleon
Authors: Kim D. Y. 
Published: May 2007

AbstractWe discuss the low energy nucleon‐nucleon interaction leading to a bound state, namely the deuteron problem. The currently known method of calculating internucleon interactions is the boson exchange potential model, where the Klein‐Gordon equation for a virtual pseudoscalar boson with a single point‐like nucleon source is solved using the Green function method. This method is known to be inadequate in particular to the internucleon problem leading to a bound state. As an alternative we propose to solve internucleon potential problems, including the bound state, by solving the Klein‐Gordon equation in which the interaction term has been introduced in a more invariant way. In the place of the single source term used in the standard method the interaction term is introduced in the covariant derivative form in the spirit of the minimum coupling scheme. It turns out that this method is not only mathematically satisfactory (gauge and Lorentz invariant formalism aspect), but also gives a more physically satisfactory interpretation of the internucleon interaction mechanism. For a deuteron bound state problem can then be solved approximately using the variational calculus. We obtain the analytic expression for the internucleon potential as a function of internucleon distances. The minimum energy value 2,2 MeV, the binding energy of the deuteron, is found to be at equilibrium distance of rab = ϱφ = 2 × 10−13 cm.
Thermodynamics of Systems of Non‐Equilibrium Momentum Distribution
Authors: Lukács B. , Martinás K. 
Published: May 2007

AbstractThere exist physical processes (e. g. in energetic heavy ion collisions), where the time scale of the process is not sufficiently long to reach complete thermal equilibrium. Here we show a way to extend the thermodynamical formalism for unequilibrium situations. The results are compatible with continuum mechanics.
Angular Gamma Dose Rate Distribution at the Surface of Injected Ducted Concrete Shield
Authors: Ahmed Fikria M. Sayed , Abboud Aida 
Published: May 2007

AbstractThe shielding problems that arise due to the irregular penetrations such as neutral beam injection ducts should be treated carefully to aid in the shield design. The present work was undertaken to describe the effects arising due to radiation streaming through the neutral beam injector ducts (NBID) on the angular distribution of the total gamma ray doses at the outer surface of illmenite concrete shield (ϱ = 4.6g/cm3). The shield is pierced with NBID of different diameters and lengths.The measurements were performed using a collimated beam of both gamma rays and neutrons emitted from one of the horizontal channels of the ET‐RR‐1 reactor. The measurements were carried out using 7LiF teflon thermoliminescent dosimeters. Generally the obtained data reveal that the presence of the total dose increase at the centerline of NBID and which in turn tends to decrease with the increase of scattered angle. An empirical formula describing the differential dose rate ratio is predicted. The experimental data obtained reveal good agreement with the calculated ones.
Planck's Orders of Magnitude and the Limits of the Quantum Gravity Conception
Authors: v. Borzeszkowski H.‐H. 
Published: May 2007

AbstractConsidering gravitational Euler scattering and energy fluctuations of gravitational Planck radiation it is shown that ‐ due to the nonlinearity of Einstein's equations ‐ there arise effective cut‐of lengths preventing the measurability of quantum vacuum effects near Planck's length.
The Formalism of Quantum Theory: An Objective Description of Reality?
Authors: Dieks D. 
Published: May 2007

AbstractWe argue that the formalism of quantum theory can be given an empirical interpretation (in the sense of a connection with observable phenomena) in the same way as in any other empirical theory. In particular, there is no need to supplement the unitary time evolution governed by a Schrödinger‐type of equation with a “projection postulate” that applies only to measurements. As a consequence, the quantum formalism has the same status as the formalisms of older physical theories, and is capable of the same philosophical interpretations. The most natural interpretation, we argue, is to conceive of the formalism as an objective – although highly abstract – description of reality.
Quantum Restrictions on Measurement of Electromagnetic Field
Authors: Mensky M. B. 
Published: May 2007

AbstractThe integration over field configurations is applied for finding quantum restrictions on measurability of electromagnetic field strength. The inequalities are derived demonstrating what precision is available for estimation, with the help of measurements, of the field strength in each point of a spacetime region. The comparison is made of the obtained results with those of the known papers by Landau and Peierls and Bohr and Rosenfeld.
Fast Neutron Albedo Calculations for a Concrete Shield with Different Curvatures
Authors: Ahmed F. M. Sayed , Salama M. 
Published: May 2007

AbstractThe O5R Monte Carlo neutron transport Code had been used to calculate the neutron albedo for neutrons reflected from plane and curved concrete shields. The present calculations were performed to investigate the fast‐neutron albedo in case of ordinary concrete shield, in order to perform comparative studies with the case of neutron reflection against a flat wall. The calculations were performed for three different neutron source energies of 1 MeV, 5 MeV and 15 MeV and at neutron incident angles of 5°, 30°, 45°, 60° and 90° and for surfaces with different curvatures (flat, 100, 50, 20 and 5 cm).The results obtained reveal that there will be an appreciable error on using the flat wall albedo value in the case of duct penetration calculations. The error was assumed to be due to the neglection of the curvature effect as well as to the improper choice of the neutron incident angle.
On the Relation between Effective Potentials and Realistic Potentials
Authors: Hassan M. Y. M. , Moharram S. , Al‐Halmoushi G. M. 
Published: May 2007

AbstractA velocity dependent effective potential of s‐ and p‐wave interaction denoted by VG2 has been applied to calculate the parameters of nuclear matter. Using this potential, the binding energy of a group of double closed shell nuclei is calculated according to the shell model. Also, the binding energy of 12C and 16O is calculated assuming Brink's model and using the VG2 interaction together with the potential deduced by Arickx et al. Reasonable agreement with experimental data is obtained.
Verfahren zur hochgenauen Bestimmung des Reflexionsvermögens von Laserspiegeln in einer Resonatoranordnung
Authors: Fiedler Roland , Schirmer Gustav , Schubert Dieter , Walther Heinz‐Günter 
Published: May 2007

AbstractWird auf geeignete Weise ein hochfrequent amplitudenmodulierter Laserstrahl geringer Linienbreite in einen passiven Resonator gekoppelt, bewirken die Resonatorgeometrie und die ReflexionsvermögenR1undR2der Resonatorspiegel eine Phasenverschiebung des Modulationssignales bezüglich eines Referenzstrahles.Durch zeitlineare Resonatorlängenänderung wird eine zeitabhängige Phasenverschiebung erzeugt, der das ProduktR1R2eindeutig zu entnehmen ist.
Studies on Thermal Neutron Backscattered by Neutral Beam Injector Ducts in Concrete Shield
Authors: Ahmed F. M. Sayed 
Published: May 2007

AbstractExperimental studies on the angular flux distributions of backscattered thermal neutrons by neutral beam injector ducts (NBID) in ilmenite concrete are performed. The neutron flux distributions have been measured at the end of the ducted assembly and perpendicular to the duct axis by means of Indium thermal detector. The experimental facility and the detector activity measurement techniques are described. Results concerning injector ducts with different diameters are graphically represented. Calculations to analyse the experimental results are given.
Sketch of a New 5‐dimensional Projective Unified Field Theory — Physical Predictions and Applications
Authors: Schmutzer E. 
Published: May 2007

AbstractSome years ago the author published a new version of a 5‐dimensional Projective Unified Field Theory unifying gravitation, electromagnetism and scalarism. Geometrically this theory is mainly based on following 5‐dimensional assumptions: symmetric metric tensor, Riemannian curvature, torsion, projector property of the basic quantities. A particular projection procedure leads from the 5‐dimensional field equations and conservation laws to 4‐dimensional ones. The 4‐dimensional scheme of equations is interpreted physically. Special interest is taken in the energy projector, describing an electrically charged perfect fluid. Several physical predictions and applications are presented.