Gravitational Waves in Matter

The theory of gravitational waves in matter is given. This covers the questions of constitutive relation, number of independent polarizations, index of refraction, reflection and refraction at an interface, etc. The theory parallels the familiar optics of electromagnetic waves in material media, but there are some striking differences. The use of the Campbell-Morgan formalism in which the gauge-invariant tidal force dyads E and B rather than the gauge-dependent metric perturbations are the unknowns is essential. The main justification of the theory at the moment is as a theoretical exercise worth doing. The assumption: size L of the medium gravitational wave length (infinite medium) rules out application to the already well-understood detection problem, but there may be an application to gravitational wave propagation through molecular gas clouds of galactic or inter-galactic size.     

Shearing apparatus for neutron scattering studies on fluids: Preliminary results for colloidal suspensions

In this paper we study the transient diffusion-limited A+B0, A₀ = B₀ annihilation via deterministic reaction-diffusion equations and via simulation of the stochastic many-particle problem. We show that the two approaches are not equivalent and that the deterministic expressions capture only part of the picture. A lower bound is derived for the density decay which indicates that the overall density follows the power law t^–x with = mm(d/4, 1). Hierarchical oscillations superimposed on the power-law decay are observed for reactions on Sierpinski gaskets.This work is dedicated to Prof. George H. Weiss.     

Analysis of the Tautomeric Properties of 2-Formylcyclopentane-1,3-Dione Using the Data of IR Spectroscopy and Nonempirical (ab initio and DFT) Quantum-Chemical Calculations

The tautomerism, spectral properties, and properties of intramolecular hydrogen bonds in 2-formylcyclopentane-1,3-dione (FCPD) have been investigated by the methods of nonempirical quantum chemistry (calculations by the ab initio and DFT methods) and IR and ¹³C NMR spectroscopy. It is shown that FCPD in a crystalline form, as also does malonic dialdehyde, exists as self-associated enolized molecules with an open chelate ring. It is found that in solutions in CCl₄ the compound investigated exists as an equilibrium mixture of its exo- and endoenolic forms, with predominance of the former. The IR spectra of the solutions of FCPD in CCl₄ fix the presence of small amounts of the associate formed from the anionic and protonated forms of the substance. For the first time, the energies of the intramolecular H bonds of the endo- and exoenolic tautomeric forms in FCPD have been estimated theoretically. They appeared to be equal to 3.69 and 4.91 kcal·mole^–1, respectively. The possible mechanisms of enol-enolic interconversions of FCPD have been discussed.     

Hopf-Algebra Description of Noncommutative-Spacetime Symmetries

A brief summary is given of the results reported in [hep-th/0306013], in collaboration with G. Amelino-Camelia and F. D'Andrea. It is focused on the analysis of the symmetries of -Minkowski noncommutative spacetime, described in terms of a Weyl map. The commutative-spacetime notion of Lie-algebra symmetries must be replaced by the one of Hopf-algebra symmetries. However, in the Hopf-algebra sense, it is possible to construct an action in -Minkowski, which is invariant under a 10-generators Poincaré-like symmetry algebra.     

Manifestation of Intermolecular Interactions in the IR Spectra of 8-Azasteroids

We have investigated the intermolecular interactions of 8-aza-D-homogona-1,3,5(10),13-tetrane-12,17a-dione and 2,3-dimethoxy-8-azagone-1,3,5(10),13-tetran-12,17-dione with CHCl₃, binary solvents CHCl₃–CH₃OH, CCl₄–CHCl₃, and CCl₄–CH₃OH and also in the solid phase, which manifest themselves in the IR spectra. When the C=O groups of the studied 8-azasteroids form hydrogen bonding with the OH groups of alcohol, the frequencies (C=O) change insignificantly. We have found that they are higher than the corresponding frequencies in the IR absorption spectra of solid-phase samples, which is attributable not only to the effect of the medium but also to the possible shortened contacts of the C=O groups with the CH₃ and CH₂ groups of the molecules under study.     

O(N) vector model with twisted boundary conditions

Prompted by a recent article of Chakravarty, we reexamine theO(N) vector model with twisted boundary conditions ind dimensions in the various frameworks of the =d–2 expansion, the =4–d expansion, and the large-N expansion. These continuum models describe the physics below the critical temperatureT _c and nearT _c of a latticeO(N) spin model. We determine the effect of the twisting on finite-size scaling functions, for various geometries.On leave from G. Nadjakov Institute of Solid State Physics, 1784 Sofia, Bulgaria.     

Non-Materiality of Non-Locality

In the present paper we show that in a certain sense the violation of Bells inequality does not entail a real non-locality. We define materiality as the capacity to be modified; and it results that in the case of the singlet state the non-locality previewed by quantum mechanics and experimentally confirmed is not material.     

IR Spectra of Derivatives of Immunotropic 8-Azasteroids

By the method of IR Fourier spectroscopy with the use of numerical differentiation of spectral line profiles we have studied the spectra of some structural and functional derivatives of immunotropic 8-azasteroids in the region of C=O and C=C bonds (1800–1400 cm^–1). We have established the dependence of vibration frequencies of the C=O and C=C groups on the size of the ring D, the presence of heteroatoms (O, S) in the ring D, transformations in the -acyl--aminovinylcarbonyl fragment and in its adjacent positions of the heterosteroid skeleton, and the composite character of the absorption bands that are due to the vibrations of the C=O and C=C groups. The role of the structural and stereoelectronic factors in the observed group frequencies of 8-azasteroids is discussed.     

A new fluorescence probe for trace metal ions: Cation-dependent spectroscopic properties

The fluorescence behavior of a new bipyridyl ligand, 2,2-bipyridyl-3,3-diol (BPDO), was studied as a function of the metal ion complexed. At pH 7.6, the fluorescence of BPDO is strongly decreased by complexation to Cu(II), but binding to Zn(II) leads to an increase in fluorescence intensity. Time-resolved fluorescence measurements suggest that in the case of Cu(II), a nonfluorescent complex is formed, whereas in the presence of Zn(II), a new, longer decay component appears.     

α-Particle Loss from Cylindrical Magnetized DT Plasma

-particles from fusion reactions in a DT magnetized plasma are confined inside the plasma not only by magnetic fields but also by induced electric fields which are due to the different mobilities of -particles and electrons. Criteria are derived for the -confinement in a cylindrical plasma, inertially confined by a heavy liner. It is observed that the suprathermal population in the DT plasma will influence the overall dynamics.     

Thickness dependence of temperature coefficient of resistance of MnBi films

In-situ measurements of the temperature coefficient of resistance of electron-beam evaporated MnBi films are reported for the thickness range 30–180 nm. The thickness dependence of the temperature coefficient of resistance curves are plotted for different weight ratios, annealing times and substrate temperatures. The temperature coefficient of resistance shows marked size effect, and is negative for lower thicknesses (<100nm) and positive for higher thicknesses. The experimental data is in good agreement with the Mayadas-Shatzkes theory. The thickness dependence of the Curie temperature also indicates marked size effect.     

On the initial layer solution of the Boltzmann equation with small Knudsen number

We extend our method of systematic removal of secular terms in a singular perturbation treatment of the Boltzmann equation with small Knudsen numbers to the initial layer. The requirement that the solution through the initial layer should connect smoothly to the normal solution removes an ambiguity noted in our previous paper. We show that removal of secular terms improves Grad's solution for the initial layer and reintroduces soundlike modes associated with higher moments, first found by Wang Chang and Uhlenbeck.     

The maximum entropy principle as a consequence of the principle of Laplace

The maximum entropy principle states that the probability distribution which best represents our information is the one which maximizes the entropy with the given evidence as constraints. We prove that this principle is implied from the Laplace principle of equiprobabilities applied to the setS of allN-term sequences of results which are compatible with the given evidence. We generalize to the information gain method of Kullback.     

Laboratory Bounds for the Cosmological Term Gradient

Effects of a spatially variable cosmologicalterm on the equation of motion are investigated, and itshown that these lead to density-dependentaccelerations. Using known data it is shown that thegradient of the cosmological term is bounded byapproximately 10^-59 cm^-3. Effectsof variable G are also discussed.     

Specific Fluorescence Properties and Picosecond Transient Absorption of 8-Azasteroids

The specific fluorescence properties as well as picosecond transient absorption features have been studied for two 8-azasteroids. It is shown that at various excitation wavelengths the essentially different final excited electronic states are realized. Because of the multicenter character of 8-azasteroids the spectroscopic data obtained may be analyzed on a basis of the mesomeric tautomerism model taking into account the dynamic combination of cis- and trans-configurations. The dependence of fluorescence spectral characteristics on the solvent nature is a manifestation of intermolecular H-bond interactions.     

Beta-decay studies of neutron-rich Sc- Cr nuclei

The neutron-rich nuclei ₂₁^{57, 58}Sc, ₂₂^58-60Ti, ₂₃^60-63V, ₂₄^62-66Cr have been produced at Ganil via interactions of a 61.8A MeV ⁷⁶Ge beam with a ⁵⁸Ni target. Beta-decay studies have been performed using combined - and -ray spectroscopy. Half-lives have been determined and -decay schemes are proposed for ⁵⁸Ti, ⁶¹V and ⁶²Cr. From these studies, new hints for the existence of -decaying isomers in ⁶⁰V and in ⁶²Mn are provided. These results are compared to shell model calculations. The role of the f_7/2- f_5/2 proton-neutron interaction is examined through its influence on the lifetime values.     

Linear Theory of the Beam-Wave Interaction in the Arbitrary Cylindrical Cerenkov Device

The hot dispersion equation in Cerenkov devices has been derived and analyzed numerically using the self-consistent linear theory. In principle, the linear analysis can be applied to efficiently calculating all kinds of beam-wave interaction in various Cerenkov devices composed of axisymmetric slow-wave structures (SWS) with arbitrary periodic profile. Then the results for Cerenkov devices with three typical SWS profiles are presented.     

Interfacial free energies and solute diffusivities from data on Ostwald ripening

Using recent theoretical modifications of the kinetic constants characterizing Ostwald ripening, it is demonstrated that accurate values of the interfacial free energy, , and solute diffusivities, D, can be obtained from experimental data when the kinetics of particle growth are measured in conjunction with independent measurements of either the decrease of the matrix supersaturation or the increase in volume fraction with aging time. The accuracy of is limited only by the assumption that the matrix phase is an ideal solid solution, and is effectively independent of the influence of equilibrium volume fraction, _e, on the kinetics of coarsening. Analyses of the available data on the coarsening of -type (Ni₃X) precipitates in binary Ni–Al, Ni–Si and Ni–Ti alloys yield values of =6.9±0.3, 10.2±3.0 and 13.0 mJ/m², respectively, assuming ideal solution thermodynamics; a more realistic thermodynamic model for the Ni–Al solid solution raises the value of in Ni–Al alloys to 8.1±0.2 mJ/m². Proportional increases probably obtain in the other two alloys. The accuracy with which D can be evaluated from comparable data depends theoretically on _e. However, analyses of the same data yield values of D in very good agreement with the results of conventional diffusion experiments. This is consistent with the absence of an effect of _e on the kinetics of Ostwald ripening in these alloys over the ranges of _e investigated.     

Strong Interactions in Strange Exotic Atoms

Strong interaction level shifts and widths in ^- and K^- atoms have been analyzed. The phenomenological density dependent approach as well as the relativistic mean field (RMF) model yield nucleus optical potentials with a repulsive real part in the nuclear interior. This has important consequences for the spectroscopy of hypernuclei. The study of K^- atoms cannot resolve the depth of the K^- nucleus potential. The fits to the kaonic atom data are satisfactory for both the relatively shallow potentials derived from chiral models and for the deep potentials based on the phenomenological and RMF analyses.     

Electrostatic Model of Edge Luminescence of Heavily Doped Degenerate Semiconductors

We propose a model of the narrowing of a forbidden band due to doping of crystalline semiconductors with hydrogenlike impurities with allowance for the following factors: spatial fluctuations of an electrostatical potential, exchange interaction of majority charge carriers, screening of the minority charge carrier by a cloud of the majority ones, and also tunneling at the level of percolation. The dependence of the position of the edge luminescence band maximum on the concentration of impurities for the degrees of their compensation from a weak to an intermediate one has been calculated. The results agree with the experimental data for cryogenic temperatures in a wide range of change in the equilibrium concentration of electrons (holes).