Volume 38, Issue 6

A new relativistic guiding center mechanics is presented that conserves energy (in timeindpendent Fields) and satisfies a Liouville's theorem. The theory reduces to Littlejohn's theory in the non-relativistic limit and agrees to leading orders in ε ≡ r g /L with the relativistic theory by Morozov and Solov'ev (which generally lacks a Liouville's theorem). The new theory is developed from an appropriate Lagrangian and is supplemented by a collisionless relativistic kinetic equation for the guiding centers. Moment equations for guiding center density and energy density are also derived

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

A transversely magnetized cylindrical plasma model with an internal rod conductor is used to approximate the FIVA internal ring device of Spherator type with a purely poloidal magnetic field. It is shown that an excitation asymmetry along the plasma column, i.e. with a wave number k 2 ≠ 0, introduces a coupling between the magnetoacoustic and shear Alfven waves in the frequency range ω ≪ ω ci . The introduction of an equilibrium mass motion along the plasma cylinder introduces a flow continuum. Simultaneously the Alfven resonance frequency becomes Doppler shifted. The experimental observations indicate that cavity modes do not build up in the FIVA device in the case of nonsymmetric excitation. If on the other hand the exciting structure becomes symmetric, i.e. with k 2 = 0, the magnetoacoustic resonances become excited. The resulting Q values are rather low which indicates that the coupling to the shear wave through the Hall electric field cannot be neglected

Introductory views are presented on the physically different but remarkably good fusion reaction performance of the dense plasma focus compared to the mainline magnetic fusion research assemblies. Reference is given to our attempt in explaining a reputed fundamental but not understood phenomenon in the focus plasma by an ion acceleration mechanism of basically the betatron type. Paradoxically, this magnetically induced plasma rotation is both contained in and denied by standard plasma equations, briefly derived and discussed with respect to validity. The neglect of the Hall term in the usual "Ideal MHD Equations" is shown to be in error with regard to current magnetic fusion research plasmas. Magnetically induced plasma rotation is derived from the ion fluid motion equation, from basic MHD fluid equations and by an analysis of the electro-magnetic torque distribution. General validity is proved by invoking usually overlooked consequences of the noncentral character of the forces sustaining quasi-neutrality. Arguments are given in favor of new approaches to magnetic fusion

The method of Unrestricted Harmonic Balance (UHB) as exposed and applied to purely timedependent systems, stiff systems, and chemical waves in the preceding 3 papers is extended to the case of transcendental functions. So, e.g., exponential functions even in mass action kinetics systems occur, if a wider range of temperature is considered as is the case in continuous stirred tank reactors (CSTR). Here the reaction heat is removed by heat exchangers, but since the volume is in most cases considerable, the system cannot be kept strictly isothermal and instabilities are known to arise. Here the oscillatory case is treated with the method of UHB

In saturated hydrocarbons dual fluorescence appears both in p-N,N-Dimethylaminobenzonitrile (DMABN) and p-N,N-Dimethylaminoethylbenzoate (DMABEE). The temperaturedependence of the fluorescence quantum yield suggests that in DMABEE E(B*) ≈ E(TICT) and in DMABN E(B*) <E(TICT)

A modified Rinzel-Keller equation of reaction-diffusion type is investigated analytically. Both on the ring and on the linear fiber, the possible existence of wavetrains containing an arbitrary finite number of impulses is demonstrated. The longest wavetrain shown explicitly consists of ten pulses. Unlike other approaches, the present method varies many parameters simultaneously. An implicit algebraic equation is formulated which contains all possible wave solutions of the system. This equation is then solved with a standard technique (Powell's algorithm). The results obtained extend the findings of other authors. The method can be applied, after appropriate modification, to other piecewise linear systems, that is, to other prototype reaction-diffusion systems

The torsional Fine structure of dimethylsulfoxide has been reinvestigated with MWFT-spectroscopy. The higher resolution results in a more accurate determination of the internal rotation barrier V 3 . The centrifugal distortion analysis is extended to sixth order. The prediction of lines is excellent, but some centrifugal distortion constants are poorly determined

Transition temperatures and critical field strengths have been observed on superconducting palladium-boron-hydrogen alloys with different boron to hydrogen ratios. Homogeneous samples. prepared by equilibrium methods, exhibit superconductivity above 3.5 K for boron contents less than x = 0.07 (x = mole boron/mole palladium). Palladium-boron alloys need less hydrogen for reaching a Fixed transition temperature than boron free alloys. Critical field strengths for T c = 0 K increase linearly with increasing boron content and reach 3.3 · 10 5 A/m at x = 0.044

In order to explain the unusual absorption characteristics of derivatives of benzopyrrole and benzodipyrrole, PPP-calculations were carried out. By means of configuration analysis the results of these calculations were interpreted in terms of molecular subunits. On the basis of this method the long wavelength absorption of this class of compounds can mainly be ascribed to the large contribution of charge transfer configurations as well as to excitonic interactions. The effect of twisting the N-phenyl bond is discussed

Molecular cations of the vinyl monomers acrolein, methylacrylate and methylmetacrylate have been prepared by irradiation at 77 K of the monomers contained in a CF 3 CCI 3 matrix. The ions have been studied by ESR. The effect of photobleaching has been investigated

The influence of molecular structure on the mesomorphic properties of thermotropic liquid crystals is discussed. The role of intermolecular attractive and repulsive (steric) forces in determining the packing and consequently the mesomorphic behaviour of the molecules is described. A correlation between the geometry of the rigid core of the molecules and the mesomorphic properties is found. The intermolecular separation strongly influences the thermodynamic stability of the mesophase. Alkyl chains do not only fill in spaces but also take part in the molecular interactions and affect the packing

The fluorescence of perylene in fluid solution (λ 0.0 = 440 nm) is quenched by silver ions in a dynamic process according to a Stern-Volmer kinetics (k q = 2 · 10 9 [1 • mol -1 · sec -1 ], in ethanol at 295 K). Simultaneously an unstructured long-wavelength emission (λ max ≈ 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 (k q ≦ 10 6 ). 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

By means of Optical Absorption, EPR and Mössbauer techniques it is demonstrated that the addition of small amounts of water to solutions of FeCl 3 in isopropanol enhances the concentration of [FeCl 4 ] - complexes, this addition leading also to the formation of ferric dimers involving two Fe 3+ -OH - bridges. An explanation of this fact based on the disproportionation of FeCl 3 and water hydrolysis is reported