Search

Abstract: The analytical expressions for the equation of state and thermo-physical quantities of Exp-6 fluid are derived based on the Ross variational perturbation theory and with the quantum effect taken into account. The formalism developed is applied to the He–H2 mixtures. The agreement of numerical results of pressure and internal energy with MC simulations is shown far better than the analytic equation of state developed by [I. Ali, S.M. Osman, N. Sulaiman, R.N. Singh, Phys. Rev. E 69 (2004) 0561045]. The isotherms for pressure, internal energy and packing factor for five concentrations and four temperatures versus volume are calculated and analyzed. The numerical results for excess Gibbs free energy and entropy of mixing are presented. The variation of the excess Gibbs free energy of mixing, and the variation of the excess entropy of mixing versus temperature and pressure are different from and similar to that of Ali et al., respectively. [Copyright &y& Elsevier]

Abstract: Dihydrogen bonds (DHBs) as a sub-class of H-bond interactions are analyzed in this paper. The results of studies on numerous DHBs obtained at the MP2/6-311++G(d,p) level of approximation are revealed. Different kinds of DHBs are investigated, from weak H⋯H interactions attributed to van der Waals interactions with binding energies amounting to less than 1kcal/mol, through DHBs of medium strength, to strong interactions possessing characteristics of covalent bonds. The Bader theory as well as the interaction energy components defined within the variation-perturbation method have been applied here to understand the nature of these interactions. Different relationships between the energetic and QTAIM (Quantum Theory of “Atoms in Molecules”) parameters are also analyzed. [Copyright &y& Elsevier]

Abstract: Doubly resonant (DR) two-dimensional (2D) three-wave-mixing (3WM) spectroscopy of a coupled multi-chromophore system in an isotropic condensed phase was theoretically studied recently [J. Chem. Phys. 126 (2007) 054505], where the signal was found to be sensitive to chirality of the coupled multi-chromophore system. This method is shown to be a useful technique for directly measuring the A- and E-symmetric amide I vibrations of three representative helical polypeptides. Furthermore, the 2D sum-frequency-generation spectra of anti-parallel and parallel β-sheet polypeptides are found to be distinctively different due to the symmetric natures of the one- and two-exciton states of these two different β-sheet polypeptides. Numerical simulations of DR 2D SFG spectra of these representative secondary structure polypeptides have been performed to demonstrate its potential use for discriminating different secondary structure polypeptides and for investigating chiral properties of vibrational one- and two-exciton states of coupled multi-chromophore systems in general. [Copyright &y& Elsevier]

Abstract: In this paper, the relationship between static vibrational and electronic hyperpolarizabilities of a series of push–pull molecules within the two-state valence-bond charge-transfer model are reinvestigated computationally at the Møller–Plesset level of theory. Although the level of theory employed here gives significantly different results for electronic and vibrational counterparts than those obtained by Bishop et al. [D. Bishop, B. Champagne, B. Kirtman, J. Chem. Phys. 109 (1998) 9987] at the RHF level, the overall conclusions remain unchanged: The comparison of ab initio computations with the predictions of the VB–CT model gives a little confidence in the latter. [Copyright &y& Elsevier]

Abstract: The bond dissociation kinetics of tethered atomic (Morse potential) chains under tensile stress is studied. Both RRKM (fully anharmonic, Monte Carlo) and RRK (harmonic appproximation) theory are applied to predict bond dissociation rate constants as a function of energy and tensile force. For chains with N ⩾3 atoms a hybrid statistical theory is used involving a harmonic approximation for motion in the transition state for bond dissociation. For chains with N =2–5 atoms, while the RRK approximation significantly overestimates the dissociation rate constant, the fully anharmonic RRKM rate is quite close to simulation results. For the N =2 chain, a novel approach to the extraction of decay rate constants based on the classical spectral theorem is implemented. Good agreement between the RRKM and dynamical rate constants is obtained for N =2 despite the fact that the reactant phase space contains a significant fraction of relatively short-lived trajectories. [Copyright &y& Elsevier]

Abstract: Recently developed quasirelativistic energy-consistent 5f-in-core pseudopotentials as well as core-polarization potentials corresponding to tetravalent actinides have been used to study the molecular structures, ionic metal–ring binding energies, and Mulliken orbital populations of the actinocenes An(C8H8)2 (An=Th–Pu). The results of Hartree–Fock calculations show only small deviations from 5f-in-valence calculations, although the 5f orbitals contribute to the covalent actinide–ring bonding. For thorocene and uranocene, second-order Møller–Plesset perturbation theory, coupled-cluster theory with single and double excitation operators and a perturbative estimate of triple excitations, and density functional theory yield actinide–ring distances which are in good agreement with the experimental values. [Copyright &y& Elsevier]

Abstract: The oxidation potentials of dihydroxyanthracene (AN) and thioxanthens (TH1–TH3) in acetonitrile have been calculated. The calculations have been performed using ab initio molecular orbital calculations (HF), and density functional theory (DFT) with the inclusion of entropic and thermochemical corrections to yield free energies of the redox reactions. The polarizable continuum model (PCM) was used to describe the solvent. The data were also obtained experimentally, with the aid of an electrochemical technique (cyclic voltammetry). The root-mean-square errors between the observed and calculated changes in the oxidation potential differences of TH group compounds in compare to those of the reference compound (AN) is just 0.043V and 0.024V for B3LYP and HF methods, respectively that provide a method by which the reduction potentials of the related molecules can be predicted more accurately. Correlation analysis between the experimental and the theoretically calculated oxidation potentials revealed that notable relations existed between the obtained oxidation potentials and the ionization potential (IP) of thioxanthens derivatives. [Copyright &y& Elsevier]

Abstract: 2-(2′-Hydroxyphenyl)benzoxazole (HBO) has been useful as a probe to study tautomerization in DNA. In order to clarify the role of water in solvating the hydrogen-bonding center of HBO, we examine here the effect of water on the ground- and excited-state properties of HBO by steady state absorption and fluorescence spectroscopy, and by ab initio calculations. The study was carried out in solvents of varying polarity and hydrogen-bonding capability and in binary mixtures of 1,4-dioxane/water and methanol/water. HBO exists in three equilibrium structures in its ground state which are solvent-dependent, solvated and closed syn-enols and anti-enol. Only closed syn-enol is able to undergo tautomerization in the excited state to form syn-keto tautomer. Fluorescence due to solvated HBO was observed at 370nm. The intensity change in the fluorescence peak at 370nm as a function of water content in the binary solvents was quantitatively analyzed. Two water molecules were found to solvate the hydrogen-bonding center of the syn-enol tautomer in the ground state. The ground-state structures of the syn-enol tautomer with one to four water molecules were calculated by performing ab initio calculations at the MP2/6–31G(d) level and it was found that only two water molecules interact with the hydrogen-bonding center of HBO, confirming the above results. As water content increased in the binary mixtures, the keto tautomer fluorescence shifted to the blue and increased in intensity. This change was attributed to the formation of an anion species in the excited state which is stabilized in high polar binary mixtures. This result was confirmed by measuring the fluorescence in aqueous solution of pH 13. At high water contents, the behavior of the binary mixtures approaches that of pure water in which HBO undergoes water-assisted tautomerization to give the syn-keto tautomer. [Copyright &y& Elsevier]

Abstract: The microstructural changes occurring in the Ta-base T-111 (Ta–8W–2Hf) alloy during 1100h thermal aging at 1098, 1248 and 1398K under inert atmosphere and the influence on mechanical properties are reported. Electrical resistivity, hardness and tensile properties are compared between the as-annealed and aged conditions. Microstructural evaluations were performed by optical, scanning electron microscopy and transmission electron microscopy. An increase in the amount of grain boundary precipitation with increasing aging temperature was found to decrease the electrical resistivity and material strength. Precipitation at the grain boundaries was found to be a mixture of monoclinic and cubic structures, suggesting the development of mixed Hf oxides, carbides and nitrides. Precipitate development caused pronounced embrittlement of the alloy following aging at 1398K. [Copyright &y& Elsevier]

Abstract: Multi-phase alloys in the Mo–Si–B system are identified as high-temperature structural materials due to their high melting points (above 2000°C) and excellent oxidation resistance attributed to the self-healing characteristics of borosilica layer up to 1400°C. In the current study, the effect of alloying additions to achieve a reduced weight density has been examined in terms of changes in the microstructure and phase stability. The critical factor underlying the microstructural changes is related to the influence of the alloying additions on the stability of the high melting temperature ternary-based Mo5SiB2 (T2) borosilicide phase. [Copyright &y& Elsevier]

Abstract: Various Mo–Re alloys are attractive candidates for use as fuel cladding and core structural materials in spacecraft reactor applications. Molybdenum alloys with rhenium contents of 41–47.5% (wt%), in particular, have good creep resistance and ductility in both base metal and weldments. However, irradiation-induced changes such as transmutation and radiation-induced segregation could lead to precipitation and, ultimately, radiation-induced embrittlement. The objective of this work is to evaluate the performance of Mo–41Re and Mo–47.5Re after irradiation at space reactor relevant temperatures. Tensile specimens of Mo–41Re and Mo–47.5Re alloys were irradiated to ∼0.7displacements per atom (dpa) at 1073, 1223, and 1373K and ∼1.4 dpa at 1073K in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Following irradiation, the specimens were strained to failure at a rate of 1×10−3 s−1 in vacuum at the irradiation temperature. In addition, unirradiated specimens and specimens aged for 1100h at each irradiation temperature were also tested. Fracture mode of the tensile specimens was determined. The tensile tests and fractography showed severe embrittlement and IG failure with increasing temperatures above 1100K, even at the lowest fluence. This high temperature embrittlement is likely the result of irradiation-induced changes such as transmutation and radiation-induced segregation. These factors could lead to precipitation and, ultimately, radiation-induced embrittlement. The objective of this work is to examine the irradiation-induced degradation for these Mo–Re alloys under neutron irradiation. [Copyright &y& Elsevier]

Abstract: Resistance spot welding (RSW) was employed to pre-join refractory alloy 50Mo–50Re (wt%) sheet with a 0.127mm gage. Five important welding parameters (hold time, electrode, ramp time, weld current and electrode force) were adjusted in an attempt to optimize the welding quality. It was found that increasing the hold time from 50ms to 999ms improved the weld strength. Use of rod-shaped electrodes produced symmetric nugget and enhanced the weld strength. Use of a ramp time of 8ms minimized electrode sticking and molten metal expulsion. The weld strength continuously increased with increasing the weld current up to 1100A, but the probabilities of occurrence of electrode sticking and molten metal expulsion were also increased. Electrode force was increased from 4.44N to 17.8N, in order to reduce the inconsistency of the welding quality. Welding defects including porosities, columnar grains and composition segregation were also studied. [Copyright &y& Elsevier]

Abstract: The changes in microstructure and mechanical properties of Mo–41Re and Mo–47.5Re alloys were investigated following 1100h thermal aging at 1098, 1248 and 1398K. The electrical resistivity, hardness and tensile properties of the alloys were measured both before and after aging, along with the alloy microstructures though investigation by optical and electron microscopy techniques. The Mo–41Re alloy retained a single-phase solid solution microstructure following 1100h aging at all temperatures, exhibiting no signs of precipitation, despite measurable changes in resistivity and hardness in the 1098K aged material. Annealing Mo–47.5Re for 1h at 1773K resulted in a two-phase αMo+σ structure, with subsequent aging at 1398 K producing a further precipitation of the σ phase along the grain boundaries. This resulted in increases in resistivity, hardness and tensile strength with a corresponding reduction in ductility. Aging Mo–47.5Re at 1098 and 1248K led to the development of the χ phase along grain boundaries, resulting in decreased resistivity and increased hardness and tensile strength while showing no loss in ductility relative to the as-annealed material. [Copyright &y& Elsevier]

Abstract: High-temperature fissile-fueled cermet literature was reviewed. Data are presented primarily for the W–UO2 as this was the system most frequently studied; other reviewed systems include cermets with Mo, Re, or alloys as a matrix. Failure mechanisms for the cermets are typically degradation of mechanical integrity and loss of fuel. Mechanical failure can occur through stresses produced from dissimilar expansion coefficients, voids created from diffusion of dissimilar materials or formation of metal hydride and subsequent volume expansion. Fuel loss failure can occur by high temperature surface vaporization or by vaporization after loss of mechanical integrity. Techniques found to aid in retaining fuel include the use of coatings around UO2 fuel particles, use of oxide stabilizers in the UO2, minimizing grain sizes in the metal matrix, minimizing impurities, controlling the cermet sintering atmosphere, and cladding around the cermet. [Copyright &y& Elsevier]

Abstract: Refractory alloys based on niobium, tantalum and molybdenum are potential candidate materials for structural applications in proposed space nuclear reactors. Long-term microstructural stability is a requirement of these materials for their use in this type of creep dominated application. Early work on refractory metal alloys has shown aging embrittlement occurring for some niobium and tantalum-base alloys at temperatures near 40% of their melting temperatures in either the base metal or in weldments. Other work has suggested microstructural instabilities during long-term creep testing, leading to decreased creep performance. This paper examines the effect of aging 1100h at 1098, 1248 and 1398K on the microstructural and mechanical properties of two niobium (Nb–1Zr and FS-85), tantalum (T-111 and ASTAR-811C) and molybdenum (Mo–41Re and Mo–47.5Re) base alloys. Changes in material properties are examined through mechanical tensile testing coupled with electrical resistivity changes and microstructural examination through optical and electron microscopy analysis. [Copyright &y& Elsevier]

Abstract: Pellets of sintered ZrN were studied to optimize the mechanical properties and microstructures needed in nitride fuel pellets, using ZrN as a surrogate for actinide nitrides and as potential component in low fertile and inert matrix fuels. Samples were prepared via sintering in either Ar or N2 (with and without 6% H2) and at 1300°C or 1600°C. A significant difference in the hardness was measured ranging from 1000 (Kg/mm2) in samples sintered at 1600°C in argon to 100 (Kg/mm2) in samples sintered at 1300°C in nitrogen. Samples with 6% hydrogen added to the sintering environment experienced a decrease in hardness, as well as an increase in intergranular cracking as compared to samples sintered without hydrogen, suggesting hydrogen embrittlement. Grain size was more uniform in samples sintered in pure Ar as compared to Ar–H2, while the latter had a larger fraction of high angle grain boundaries than the former. Cracking around indents had a clear tendency to follow high angle boundaries, which were found to be intrinsically weak in ZrN. [Copyright &y& Elsevier]

Abstract: For safe and reliable operation of fission reactors in space, the phase diagrams and reaction kinetics of systems used as nuclear fuels, such as U–O, U–N, U–C, are required. Diffraction allows identification of phases and their weight fractions as a function of temperature in situ, with a time resolution of the order of minutes. In this paper, we will provide results from a neutron diffraction experiment studying the U–O system. Using the neutron diffractometer HIPPO, the decomposition of UO2+x into UO2 and U4O9 as a function of temperature was investigated in situ. From the diffraction data, the participating phases could be identified as UO2+x , UO2 and U4O8.94 and no stoichiometric U4O9 was found. Results of the experiment were used to improve existing thermodynamic models. The presented techniques (i.e., neutron diffraction and thermodynamic modeling) are also applicable to the other systems mentioned above. [Copyright &y& Elsevier]

Abstract: The reaction is a very good isospin 3/2 filter for studying decaying to . With an effective Lagrangian approach, contributions from a previous ignored sub--threshold resonance are fully included in addition to those already considered in previous calculations. It is found that the resonance gives an overwhelmingly dominant contribution for energies very close to threshold, with a very important contribution from the t-channel ρ exchange. This solves the problem that all previous calculations seriously underestimate the near-threshold cross section by order(s) of magnitude. Many important implications of the results are discussed. [Copyright &y& Elsevier]

Abstract: One-parameter exactly separable versions of the X(5) and X(5)- models, labelled as ES-X(5) and ES-X(5)- respectively, are derived by using in the Bohr Hamiltonian potentials of the form . Unlike X(5), in these models the and bands are treated on equal footing. Spacings within the band are well reproduced by both models, while spacings within the band are well reproduced only by ES-X(5)-, for which several nuclei with ratios and [normalized to ] and bandheads corresponding to the model predictions have been found. [Copyright &y& Elsevier]

Abstract: In frame of a phenomenological approach based on Compton-like Feynman amplitudes, we study multi-pion production in antiproton nucleon collisions. The main interest of this reaction is related to the possibility to study the properties of the presumable atom and of its resonances. For the case of formation of a scalar or pseudoscalar resonant state, with numerical results are obtained. The differential cross section in an experimental set-up where the pions invariant mass is measured, is given with explicit dependence on the lepton pair and pions invariant mass. [Copyright &y& Elsevier]

Abstract: Conventional nucleon–nucleon potentials with strong short-range repulsion require contributions from high-momentum wave function components even for low-energy observables such as the deuteron binding energy. This can lead to the misconception that reproducing high-energy phase shifts is important for such observables. Interactions derived via the similarity renormalization group decouple high-energy and low-energy physics while preserving the phase shifts from the starting potential. They are used to show that high-momentum components (and high-energy phase shifts) can be set to zero when using low-momentum interactions, without losing information relevant for low-energy observables. [Copyright &y& Elsevier]

Abstract: We consider the fermionic contributions to the free energy of noncommutative QED at finite temperature T. This analysis extends the main results of our previous investigation where we have considered the pure bosonic sector of the theory. For large values of (θ is the magnitude of the noncommutative parameters) the fermionic contributions decrease the value of the critical temperature, above which there occurs a thermodynamic instability. [Copyright &y& Elsevier]

Abstract: We present holographic arguments to predict properties of strongly coupled gravitational systems in terms of weakly coupled gauge theories. In particular we relate the latest computed value for the Choptuik critical exponent in black hole formation in five dimensions, , to the saturation exponent of four-dimensional Yang–Mills theory in the Regge limit, . [Copyright &y& Elsevier]

Abstract: We have studied the scalar field as well as the fermionic field perturbations in the background of the massless BTZ black holes. Comparing with the perturbation results in the generic non-rotating BTZ black hole background, we found that the massless BTZ hole contains only normal modes in the perturbations. We argued that this special property reflects that the massless BTZ black hole is a different phase from that of the generic non-rotating BTZ hole. [Copyright &y& Elsevier]

Abstract: The distribution of the decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: , , . The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion–pion rescattering, which is in preparation. [Copyright &y& Elsevier]

Abstract: The soft breaking of gauge or other symmetries is the typical Quantum Field Theory phenomenon. In many cases one can apply the Stückelberg procedure, which means introducing some additional field or fields and restore the gauge symmetry. The original softly broken theory corresponds to a particular choice of the gauge fixing condition. In this Letter we use this scheme for performing quantum calculations for some softly broken gauge theories in an arbitrary curved space–time. The following examples are treated in details: Proca field, massive QED and massive torsion coupled to fermion. Furthermore we present a qualitative discussion of the discontinuity of quantum effects in the massive spin-2 field theory, paying special attention to the similarity and differences with the massless limit in the spin-1 case. [Copyright &y& Elsevier]

Abstract: We present arguments for the existence of charged, rotating black holes with equal-magnitude angular momenta in an odd number of dimensions . These solutions possess a regular horizon of spherical topology and approach asymptotically the anti-de Sitter spacetime background. We analyze their global charges, their gyromagnetic ratio and their horizon properties. [Copyright &y& Elsevier]

Abstract: We investigate perturbative aspects of gravity with a general Lagrangian, as well as nonperturbative dilatonic solutions. For the first part, we are interested in stability and the definition of asymptotic charges. The main result of this study is that, while generic theories are stable under metric perturbations, they are expected to show instabilities against curvature perturbations when the Lagrangian includes terms. For the second part, one is interested on exact solutions, and we explicitly construct kink-like solutions of the Liouville type for the dilaton field for having the form , in two and in four dimensions. [Copyright &y& Elsevier]

Abstract: We discuss FRW universe with time-dependent EoS dark fluid which leads to multiple de Sitter space. This model (as well as its scalar-tensor version) may be considered as some classical analog of cosmological landscape. The universe expansion history may look as transitions between different de Sitter eras what suggests the interesting solution for cosmological constant problem. For specific time-dependent EoS dark fluid the possibility of transitions between universe regions with positive and negative cosmological constant is also established. [Copyright &y& Elsevier]

Abstract: We consider constraints on long-lived charged scalar leptons in supersymmetric models, where gravitino is the lightest superparticle. We study the decay and hadronization processes of . We also take into account the significant enhancement of 6L production due to the formation of the bound-state ; for this purpose, we use the reaction rate given by the most recent calculation based on coupled-channel method. [Copyright &y& Elsevier]

Abstract: A low-energy non-unitary leptonic mixing matrix is a generic effect of a large class of theories accounting for neutrino masses. It is shown how the extra CP-odd phases of a general non-unitary matrix allow for sizeable CP-asymmetries in channels other than those dominant in the standard unitary case. The channel turns out to be an excellent tool to further constrain moduli and phases. Furthermore, we clarify the relationship between our approach and the so-called “non-standard neutrino interactions” schemes: the sensitivities explored here apply as well to such constructions. [Copyright &y& Elsevier]

Abstract: We present analytical results for all six-photon helicity amplitudes. For the computation of this loop induced process two recently developed methods, based on form factor decomposition and on multiple cuts, have been used. We obtain compact results, demonstrating the applicability of both methods to one-loop amplitudes relevant to precision collider phenomenology. [Copyright &y& Elsevier]

Abstract: Correlations between p and at transverse momenta typical of enhanced baryon production in Au+Au collisions are reported. The PHENIX experiment has measured same and opposite sign baryon pairs in Au+Au collisions at . Correlated production of p and with the trigger particle from the range and the associated particle with is observed to be nearly independent of the centrality of the collisions. Same sign pairs show no correlation at any centrality. The conditional yield of mesons triggered by baryons (and anti-baryons) and mesons in the same range rises with increasing centrality, except for the most central collisions, where baryons show a significantly smaller number of associated mesons. These data are consistent with a picture in which hard scattered partons produce correlated p and in the region of the baryon excess. [Copyright &y& Elsevier]

Abstract: In this work we show that the existence of a complete biorthonormal set of eigenvectors of the effective Hamiltonian governing the time evolution of neutral meson system is a necessary condition for diagonalizability of such a Hamiltonian. We also study the possibility of probing the CPT invariance by observing the time dependence of cascade decays of type by employing such basis and exactly determine the CPT violation parameter by comparing the time dependence of the cascade decays of tagged and tagged . [Copyright &y& Elsevier]

Abstract: The quality of the narrow-width approximation is examined for partonic and convolved cross sections of sample processes. By comparison with accurate predictions significant limitations are revealed. [Copyright &y& Elsevier]

Abstract: I propose a scaling analysis of the hadron multiplicity ratio measured in Deep Inelastic Scattering on nuclear targets as a tool to distinguish energy loss and nuclear absorption effects on hadron suppression in cold nuclear matter. The proposed scaling variable is a function of the hadron fractional energy and of the virtual photon energy. Its functional form, which depends on a parameter λ, can be fixed by general theoretical considerations and encompasses both energy loss and absorption models. The parameter λ is fitted to HERMES experimental data and shown to favor prehadron nuclear absorption as leading mechanism for hadron suppression as opposed to quark energy loss. [Copyright &y& Elsevier]

Abstract: The transition from asymmetric to symmetric fission as dependent on the excitation energy and nucleon composition of fissioning Th and Pa nuclei is investigated for the 232Th(n, F) and 232Th(p, F) reactions, respectively. Observed neutron-induced fission cross sections are described in a fission/evaporation approximation. A separate relatively high outer fission barrier with significant curvature was assumed for the symmetric mode, while the inner one () was assumed to be the same for symmetric and asymmetric modes. Axial asymmetry and mass symmetry is assumed for the outer saddle of the SL-mode, as distinct from the AS-mode. A drop of to ∼1–1.5 MeV for Th and Pa nuclei with is responsible for the increase of the symmetric fission contribution to 225,229,230,231,232Th(n, F) or 232Th(p, F) fission cross sections with nucleon energy up to . It is shown that with increase of the above the 229,230,231,232Th(n, F) fission cross sections are no longer dependent on the Th target nuclide fissility. The dependence of 232Th fission cross section on the incident particle (n or p) is predicted to be different than in case of 238U target nuclide. [Copyright &y& Elsevier]

Abstract: We present the results of a complete two-loop calculation at order of the nucleon mass in manifestly Lorentz-invariant chiral perturbation theory. The renormalization is performed using the reformulated infrared renormalization, which allows for the treatment of two-loop integrals while preserving all relevant symmetries, in particular chiral symmetry. [Copyright &y& Elsevier]

Abstract: A measurement of the neutrino asymmetry is presented which represents the first search for new physics using polarized radioactive atoms initially cooled and confined in a magneto-optical trap. Optical pumping and photoionization techniques are used to generate and measure, in situ, a highly spin-polarized sample of the short-lived -emitter 37K. The angular distribution of neutrinos from this polarized decay, inferred from the daughter recoil asymmetry, is used to search for a hypothetical current in the weak interaction. We find the ν asymmetry parameter to be , in agreement with the standard model''s purely interaction. [Copyright &y& Elsevier]

This paper summarizes the pillars of FTG, updates it and uses FTG to identify and rectify the errors of physics. It also highlights the major new applications of FTG. [ABSTRACT FROM AUTHOR]

In this contribution a brief overview of the status and perspectives of the theoretical methods for studying light and heavy nuclear systems is presented. [ABSTRACT FROM AUTHOR]

This paper deals with Aristotle's concept of chance, such as it is presented in Physics II 4-6. The central section of the article concentrates on an analysis of Aristotle's definition of chance and its essential peculiarities: the fact of being an incidental (efficient) cause and the fact of existing in the domain of what is for the sake of an end. According to Rossi, both characteristics would correspond to a causal aspect (in an incidental sense) and to a non causal aspect (or just apparently causal) of chance. Finally, the author also tries to show the structural connection between the aforementioned aspects, taking as a key point the thesis of coincidence among the formal, final, and efficient causes. [ABSTRACT FROM AUTHOR]

This essay attempts to offer a reconstruction of Aristotle's arguments in favor of the use of teleological explanations in Physics II 8. In his exposition of the selected passages Ross makes some emphasis upon the dialogical character of discourse in order to make a modest contribution to the solution of two puzzles: one exegetical in character and the other systematic. This reading allows the author to introduce a new element in the discussion concerning what the scopes and limits of teleological explanations are in Aristotle's Physics. In Ross' view, this strategy is helpful for advancing in the understanding of which is the type of arguments that can be offered when what is under consideration is whether teleology or mechanism are the most proper explicative scheme to account for the natural phenomena. [ABSTRACT FROM AUTHOR]

Abstract: A novel technique is presented, which uses dI ce /dt and the transconductance as a thermo-sensitive parameter for the measurement of the static and of the transient average junction temperature in IGBT devices. The paper describes the physics of the signal generation, provides the experimental setup, and discusses the accuracy and the suitability of the technique under operating conditions of the devices. [Copyright &y& Elsevier]

Nanoindentation has become a commonplace tool for the measurement of mechanical properties at small scales, but may have even greater importance as a technique for experimental studies of fundamental materials physics. With high-resolution load-displacement data, discrete events including dislocation source activation, shear instability initiation, and phase transformations can be detected during a nanoindentation test. Recently-developed capabilities in, for example, high-temperature nanoindentation testing and in situ imaging of the indented volume, offer new quantitative details about these phenomena, and present many opportunities for future scientific inquiry. [Copyright &y& Elsevier]

In textbooks and popular writings physicists repeat familiar stories about the history of physics that historians have long identified as myths. Examples of remarks about Galileo and Aristotle are used to illustrate this practice. These examples lead to a discussion of several reasons why these myths might play a positive role for physicists and whether physicists can dispense with myths about the history of their field. [ABSTRACT FROM AUTHOR]

We report the results of a study on students' interest in physics at the end of their compulsory schooling in Israel carried out in the framework of the ROSE Project. Factors studied were their opinions about science classes, their out-of-school experiences in physics, and their attitudes toward science and technology. Students' overall interest in physics was "neutral" (neither positive nor negative), with boys showing a higher interest than girls. We found a strong correlation between students' "neutral" interest in physics and their negative opinions about science classes. These findings raise serious questions about the implementation of changes made in the Israeli science curriculum in primary and junior high school, especially if the goal is to prepare the young generation for life in a scientific-technological era. A more in-depth analysis of the results led us to formulate curricular, behavioral, and organizational changes needed to reach this goal. [ABSTRACT FROM AUTHOR]

The distinction between proper and improper mixtures is a staple of the discussion of foundational questions in quantum mechanics. Here we note an analogous distinction in the context of the theory of entanglement. The terminology of "proper" versus "improper" separability is proposed to mark the distinction. [ABSTRACT FROM AUTHOR]

Abstract: We propose a scheme by which two parties can secretly and simultaneously exchange messages. The scheme requires the two parties to share entanglement and both to perform Bell-state measurements. Only two out of the four Bell states are required to be distinguished in the Bell-state measurements, and thus the scheme is experimentally feasible using only linear optical means. Generalizations of the scheme to high-dimensional systems and to multipartite entanglement are considered. We show also that the proposed scheme works even if the two parties do not possess shared reference frames. [Copyright &y& Elsevier]

Optimal observables are known to lead to minimal statistical errors on parameters for a given normalised event distribution of a physics reaction. Thereby all statistical correlations are taken into account. Therefore, on the one hand they are a useful tool to extract values on a set of parameters from measured data. On the other hand one can calculate the minimal constraints on these parameters achievable by any data-analysis method for the specific reaction. In case the final states can be reconstructed without ambiguities optimal observables have a particularly simple form. We give explicit formulae for the optimal observables for generic reactions in case of ambiguities in the reconstruction of the final state and for general parameterisation of the final-state phase space. [ABSTRACT FROM AUTHOR]