Thermoluminescence systems with two or more glow peaks described by anomalous kinetic parameters

The usual first and second order TL kinetic expressions are based on a number of assumptions, including the usually unstated assumption that charges released from one type of trap, giving rise to one glow peak, are not retrapped on other types of traps, associated with other glow peaks. Equations have been developed describing TL systems in which charges released from one type of trap may be retrapped in other types of traps. Called interactive kinetic equations, they are quite simple but have been studied by numerical methods. In particular, glow curves computed from the interactive kinetic equations have been regarded as data and analyzed by fitting them to the usual first and second order kinetic expressions. All of the anomalous features described above are reproduced. For example, usually the computed glow peaks are well fitted by the first and second order expressions over their upper 60 to 80% but not in the wings. This explains why the usual analysis methods, especially those utilizing peak temperature, full width, etc. appear to describe such peaks. Often unrealistic kinetic parameters are often obtained. Furthermore, the computed glow curves often reproduce the observed dependence on dose

Transport properties of clean and disordered superconductors in matrix field theory

A comprehensive field theory is developed for superconductors with quenched disorder. We first show that the matrix field theory, used previously to describe a disordered Fermi liquid and a disordered itinerant ferromagnet, also has a saddle-point solution that describes a disordered superconductor. A general gap equation is obtained. We then expand about the saddle point to Gaussian order to explicitly obtain the physical correlation functions. The ultrasonic attenuation, number density susceptibility, spin density susceptibility and the electrical conductivity are used as examples. Results in the clean limit and in the disordered case are discussed respectively. This formalism is expected to be a powerful tool to study the quantum phase transitions between the normal metal state and the superconductor state.Comment: 9 page

Response function analysis of excited-state kinetic energy functional constructed by splitting k-space

Over the past decade, fundamentals of time independent density functional theory for excited state have been established. However, construction of the corresponding energy functionals for excited states remains a challenging problem. We have developed a method for constructing functionals for excited states by splitting k-space according to the occupation of orbitals. In this paper we first show the accuracy of kinetic energy functional thus obtained. We then perform a response function analysis of the kinetic energy functional proposed by us and show why method of splitting the k-space could be the method of choice for construction of energy functionals for excited states.Comment: 11 page

Parity Violation in Proton-Proton Scattering

Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at 230 MeV and near 1.3 GeV. These experiments are intended to provide stringent constraints on the set of six effective weak meson-nucleon coupling constants, which characterize the weak interaction between hadrons in the energy domain where meson exchange models provide an appropriate description. The 221 MeV is unique in that it selects a single transition amplitude (3P2-1D2) and consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The TRIUMF 221 MeV proton-proton parity violation experiment is described in some detail. A preliminary result for the longitudinal analyzing power is Az = (1.1 +/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are commented on. The anomaly at 6 GeV/c requires that a new multi-GeV proton-proton parity violation experiment be performed.Comment: 13 Pages LaTeX, 5 PostScript figures, uses espcrc1.sty. Invited talk at QULEN97, International Conference on Quark Lepton Nuclear Physics -- Nonperturbative QCD Hadron Physics & Electroweak Nuclear Processes --, Osaka, Japan May 20--23, 199

Effective action and density functional theory

The effective action for the charge density and the photon field is proposed as a generalization of the density functional. A simple definition is given for the density functional, as the functional Legendre transform of the generator functional of connected Green functions for the density and the photon field, offering systematic approximation schemes. The leading order of the perturbation expansion reproduces the Hartree-Fock equation. A renormalization group motivated method is introduced to turn on the Coulomb interaction gradually and to find corrections to the Hartree-Fock and the Kohn-Sham schemes.Comment: New references and a numerical algorithm added, to appear in Phys. Rev. B. 30 pages, no figure

Enriching an effect calculus with linear types

Abstract. We define an enriched effect calculus by extending a type theory for computational effects with primitives from linear logic. The new calculus provides a formalism for expressing linear aspects of computational effects; for example, the linear usage of imperative features such as state and/or continuations. Our main syntactic result is the conservativity of the enriched effect calculus over a basic effect calculus without linear primitives (closely related to Moggi’s computational metalanguage, Filinski’s effect PCF and Levy’s call-by-push-value). The proof of this syntactic theorem makes essential use of a category-theoretic semantics, whose study forms the second half of the paper. Our semantic results include soundness, completeness, the initiality of a syntactic model, and an embedding theorem: every model of the basic effect calculus fully embeds in a model of the enriched calculus. The latter means that our enriched effect calculus is applicable to arbitrary computational effects, answering in the positive a question of Benton and Wadler (LICS 1996).

A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

TRIUMF experiment E497 is a study of parity violation in pp scattering at an energy where the leading term in the analyzing power is expected to vanish, thus measuring a unique combination of weak-interaction flavour conserving terms. It is desired to reach a level of sensitivity of 2x10^-8 in both statistical and systematic errors. The leading systematic errors depend on transverse polarization components and, at least, the first moment of transverse polarization. A novel polarimeter that measures profiles of both transverse components of polarization as a function of position is described.Comment: 19 pages LaTeX, 10 PostScript figures. To appear in Nuclear Instruments and Methods in Physics Research, Section

Magneto-transport in a quantum network: Evidence of a mesoscopic switch

We investigate magneto-transport properties of a $\theta$ shaped three-arm mesoscopic ring where the upper and lower sub-rings are threaded by Aharonov-Bohm fluxes $\phi_1$ and $\phi_2$, respectively, within a non-interacting electron picture. A discrete lattice model is used to describe the quantum network in which two outer arms are subjected to binary alloy lattices while the middle arm contains identical atomic sites. It is observed that the presence of the middle arm provides localized states within the band of extended regions and lead to the possibility of switching action from a high conducting state to a low conducting one and vice versa. This behavior is justified by studying persistent current in the network. Both the total current and individual currents in three separate branches are computed by using second-quantized formalism and our idea can be utilized to study magnetic response in any complicated quantum network. The nature of localized eigenstates are also investigated from probability amplitudes at different sites of the quantum device.Comment: 7 pages, 9 figure

Application of Bayesian statistics to estimate nitrous oxide emission factors of the nitrogen fertilisers in UK grasslands

Trapezoidal integration by linear interpolation of data points is by far the most commonly used method of cumulative flux calculations of nitrous oxide (N2O) in studies that use flux chambers; however, this method is incapable of providing accurate uncertainty estimates. A Bayesian approach was used to calculate N2O emission factors (EFs) and their associated uncertainties from flux chamber measurements made after the application of nitrogen fertilisers, in the form of ammonium nitrate (AN), urea (Ur) and urea treated with Agrotain® urease inhibitor (UI) at four grassland sites in the UK. The comparison between the cumulative fluxes estimated using the Bayesian and linear interpolation methods were broadly similar (R2=0.79); however, the Bayesian method was capable of providing realistic uncertainties when a limited number of data points is available. The study reports mean EF values (and 95% confidence intervals) of 0.60 ± 0.63, 0.29 ± 0.22 and 0.26 ± 0.17% of applied N emitted as N2O for the AN, Ur and UI treatments, respectively. There was no significant difference between N2O emissions from the Ur and UI treatments. In the case of the automatic chamber data collected at one site in this study, the data did not fit the log-normal model, implying that more complex models may be needed, particularly for measurement data with high temporal resolutioninfo:eu-repo/semantics/publishedVersio