Chemical Phase Analysis

In many scientific investigations and technical operations it is necessary to know not only the total amount of an element of interest but also the amount of its different valencies , combinations or mineralogical forms. The diff-erent phases or forms of an element can usually be obser-ved of course by microscopical examination, X-ray diff-raction or other physical means . The frequent difficulty of obtaining by these techniques a rapid quantitative measure of the phases present. has led to the dcvelopiucut of many chemical procedures, based principally on a sele-ctive solvent , a chelate, resin or other isolating agent. The chemical approach , though it may suffer from certain deficiencies in accuracy and precision , has the merit of quickly providing a reasonable satisfactory result. It does not require expensive and complicated instruments or workers with long experience in the interpretation of data . The popularity of chemical phase analysis in indu-strial practice, therefore , is not difficult to understan

Recovering purity with comonads and capabilities

© 2020 Owner/Author. In this paper, we take a pervasively effectful (in the style of ML) typed lambda calculus, and show how to extend it to permit capturing pure expressions with types. Our key observation is that, just as the pure simply-typed lambda calculus can be extended to support effects with a monadic type discipline, an impure typed lambda calculus can be extended to support purity with a comonadic type discipline. We establish the correctness of our type system via a simple denotational model, which we call the capability space model. Our model formalises the intuition common to systems programmers that the ability to perform effects should be controlled via access to a permission or capability, and that a program is capability-safe if it performs no effects that it does not have a runtime capability for. We then identify the axiomatic categorical structure that the capability space model validates, and use these axioms to give a categorical semantics for our comonadic type system. We then give an equational theory (substitution and the call-by-value ß and • laws) for the imperative lambda calculus, and show its soundness relative to this semantics. Finally, we give a translation of the pure simply-typed lambda calculus into our comonadic imperative calculus, and show that any two terms which are ß•-equal in the STLC are equal in the equational theory of the comonadic calculus, establishing that pure programs can be mapped in an equation-preserving way into our imperative calculus

New limits on top squark NLSP from ATLAS 4.7 fb−1fb^{-1} data

Using the ATLAS 4.7 $fb^{-1}$ data on new physics search in the jets + \met channel, we obtain new limits on the lighter top squark ($\tilde t_1$) considering all its decay modes assuming that it is the next to lightest supersymmetric particle (NLSP). If the decay \lstop \ra c \lspone dominates and the production of dark matter relic density is due to NLSP - LSP co-annihilation then the lower limit on \mlstop is 240 GeV. The limit changes to 200 GeV if the decay \lstop \ra b W \lspone dominates. Combining these results it follows that \lstop NLSP induced baryogenesis is now constrained more tightly.Comment: 9 pages, 2 figures, published in MPL

Binary corrected X-ray light curve of Cygnus X-3 : implications for the timing properties of the compact binary system

We study the binary corrected X-ray light curve of Cygnus X-3 using the RXTE-ASM data and RXTE-PCA data. We find that the X-ray template derived from the EXOSAT observations adequately explains the binary variations. Using the recently determined quadratic binary ephemeris we correct the RXTE-PCA lightcurve and obtain the power spectrum which shows distinct features of shifting towards the low frequency regime vis-a-vis the Galactic X-ray binaries. The power spectrum doesn't vary from the hard to the soft state. We also obtain the binary corrected RXTE-ASM monitoring lightcurve and examine the previously obtained correlation between soft X-ray (2-12 keV from RXTE-ASM), hard X-ray (20-100 keV from CGRO-BATSE) and radio (2.2 GHz from GBI) after the binary correction. We find that the correlation time scale is less than a day.Comment: Accepted for publication in Astronomy & Astrophysic

Comparison of perturbative expansions using different phonon bases for two-site Holstein model

The two-site single-polaron problem is studied within the perturbative expansions using different standard phonon basis obtained through the Lang Firsov (LF), modified LF (MLF) and modified LF transformation with squeezed phonon states (MLFS). The role of these convergent expansions using the above prescriptions in lowering the energy and in determining the correlation functions are compared for different values of coupling strength. The single-electron energy, oscillator wave functions and correlation functions are calculated for the same system. The applicability of different phonon basis in different regimes of the coupling strength as well as in different regimes of hopping are also discussed.Comment: 24 pages (RevTEX), 12 postscript figures, final version accepted in PRB(2000) Jornal Ref: Phys. Rev. B, 61, 4592-4602 (2000

TeV-scale electron Compton scattering in the Randall-Sundrum scenario

The spin-2 graviton excitations in the Randall-Sundrum gravity model provides a t-channel contribution to electron Compton scattering which competes favourably with the standard QED contributions. The phenomenological implications of these contributions to the unpolarized and polarized cross-sections are evaluated.Comment: 11 pages, 5 figure

Fractal Inspired Models of Quark and Gluon Distributions and Longitudinal Structure Function FL(x, Q2) at small x

In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based approximate relation between the longitudinal structure function and the gluon density. As the Altarelli-Martinelli equation for the longitudinal structure function cannot be applied to Model I due to the presence of a singularity in the Bjorken x-space we consider Model II only. The qualitative feature of the prediction of Model II is found to be compatible with the QCD expectation.Comment: 11 pages, 4 figures, Accepted for publication on 10-07-2010 in Indian Journal of Physic

The production of the new gauge boson BHB_{H} via e−γe^{-}\gamma collision in the littlest Higgs model

The new lightest gauge boson $B_H$ with mass of a few hundred GeV is predicted in the littlest Higgs model. $B_H$ should be accessible in the planed ILC and the observation of such particle can strongly support the littlest Higgs model. The realization of $\gamma\gamma$ and $e\gamma$ collision will open a wider window to probe $B_H$. In this paper, we study the new gauge boson $B_{H}$ production processes $e^{-}\gamma\to e^{-}\gamma B_{H}$ and $e^{-}\gamma\to e^{-}Z B_{H}$ at the ILC. Our results show that the production cross section of the process $e^{-}\gamma\to e^{-}Z B_{H}$ is less than one fb in the most parameter spaces while the production cross section of the process $e^{-}\gamma\to e^{-}\gamma B_{H}$ can reach the level of tens fb and even hundreds of fb in the sizable parameter spaces allowed by the electroweak precision data. With the high luminosity, the sufficient typical signals could be produced, specially via $e^{-}\gamma\to e^{-}\gamma B_{H}$. Because the final electron and photon beams can be easily identified and the signal can be easily distinguished from the background produced by $Z$ and $H$ decaying, $B_H$ should be detectable via $e\gamma$ collision at the ILC. Therefore, the processes $e^{-}\gamma\to e^{-}\gamma B_{H}$ and $e^{-}\gamma\to e^{-}Z B_{H}$ provide a useful way to detect $B_{H}$ and test the littlest Higgs model.Comment: 15 pages, 3 figures. Some typos have been corrected, we have added some new references, and there are also some changes in equation 1

N-wave interactions related to simple Lie algebras. Z_2- reductions and soliton solutions

The reductions of the integrable N-wave type equations solvable by the inverse scattering method with the generalized Zakharov-Shabat systems L and related to some simple Lie algebra g are analyzed. The Zakharov- Shabat dressing method is extended to the case when g is an orthogonal algebra. Several types of one soliton solutions of the corresponding N- wave equations and their reductions are studied. We show that to each soliton solution one can relate a (semi-)simple subalgebra of g. We illustrate our results by 4-wave equations related to so(5) which find applications in Stockes-anti-Stockes wave generation.Comment: 18 pages, 1 figure, LaTeX 2e, IOP-style; More clear exposition. Introduction and Section 5 revised. Some typos are correcte