Bound q\bar q Systems in the Framework of the Different Versions of the 3-Dimensional Reductions of the Bethe-Salpeter Equation

Bound q\bar q systems are studied in the framework of different 3-dimensional relativistic equations derived from the Bethe-Salpeter equation with the instantaneous kernel in the momentum space. Except the Salpeter equation, all these equations have a correct one-body limit when one of the constituent quark masses tends to infinity. The spin structure of the confining qq interaction potential is taken in the form $x\gamma_{1}^{0}\gamma_{2}^{0}+(1-x)I_{1}I_{2}$, with $0\leq x \leq 1$. At first stage, the one-gluon-exchange potential is neglected and the confining potential is taken in the oscillator form. For the systems (u\bar s), (c\bar u), (c\bar s) and (u\bar u), (s\bar s) a comparative qualitative analysis of these equations is carried out for different values of the mixing parameter x and the confining potential strength parameter. We investigate: 1)the existence/nonexistence of stable solutions of these equations; 2) the parameter dependence of the general structure of the meson mass spectum and leptonic decay constants of pseudoscalar and vector mesons. It is demonstrated that none of the 3-dimensional equations considered in the present paper does simultaneously describe even general qualitative features of the whole mass spectrum of q\bar q systems. At the same time, these versions give an acceptable description of the meson leptonic decay characteristics.Comment: 22 pages, 5 postscript figures, LaTeX-file (revtex.sty

Elastic Pion Scattering on the Deuteron in a Multiple Scattering Model

Pion elastic scattering on deuterium is studied in the KMT multiple scattering approach developed in momentum space. Using a Paris wave function and the same methods and approximations as commonly used in pion scattering on heavier nuclei excellent agreement with differential cross section data is obtained for a wide range of pion energies. Only for $T_{\pi}>250$ MeV and very backward angles, discrepancies appear that are reminiscent of disagreements in pion scattering on $^3$He, $^3$H, and $^4$He. At low energies the second order corrections have been included. Polarization observables are studied in detail. While tensor analyzing powers are well reproduced, vector analyzing powers exhibit dramatic discrepancies.Comment: 25 pages LATEX and 9 postscript figures in a self-extracting uufile archiv

Comprehensive Methodology for Investigation of Middle Fractions of Petroleum

A methodology has been developed for separation and identification of hydrocarbons of middle 250-350°C fractions of Taribani and Mirzaani petroleum (Georgia) in order to determine their individual hydrocarbon composition. The middle fractions of petroleum are difficult to study objects due to the huge variety of hydrocarbon isomers present in them.The methodology includes the following complex of physical and chemical methods for processing of petroleum: distillation, dearomatization by adsorption chromatography, thorough separation of isoalkanes from cycloalkanes using three stages thermal diffusion, processing of the obtained concentrates with thiocarbamide. To determine the individual composition of the fractions, instrumental methods of gasliquid chromatography analysis on capillary columns, MS and GC/MS were used. The developed methodology has been successfully applied to the separation of paraffinic, isoparaffinic and cycloparaffinic hydrocarbons and to determine molecular composition of the middle fractions. Separation of isomers from the concentrates obtained by way of thermal diffusion fractions of Taribani and Mirzaani petroleum was achieved and a number of isoprenoids of C11-C23 composition were identified, in thiocarbamide concentrates there were polycyclic alkanes of C11-C16 composition, and in filtrates - relict, polymethyl-substituted decalins of C14-C16 compositio

Cost-effectiveness of pneumococcal conjugate vaccination in Georgia.

OBJECTIVE: Financial support from the Global Alliance for Vaccines and Immunization (GAVI) to introduce the 10-valent pneumococcal conjugate vaccine (PCV10) into the routine childhood immunization schedule in Georgia is ending in 2015. As a result, the Interagency Coordination Committee (ICC) decided to carry out a cost-effectiveness analysis to gather additional evidence to advocate for an appropriate evidence-based decision after GAVI support is over. The study also aimed to strengthen national capacity to conduct cost-effectiveness studies, and to introduce economic evaluations into Georgia's decision-making process. METHODOLOGY: A multidisciplinary team of national experts led by a member of the ICC carried out the analysis that compared two scenarios: introducing PCV10 vs no vaccination. The TRIVAC model was used to evaluate 10 cohorts of children over the period 2014-2023. National data was used to inform demographics, disease burden, vaccine coverage, health service utilization, and costs. Evidence from clinical trials and the scientific literature was used to estimate the impact of the vaccine. A 3+0 schedule and a vaccine price increasing to US$3.50 per dose was assumed for the base-case scenario. Alternative univariate and multivariate scenarios were evaluated. RESULTS: Over the 10-year period, PCV10 was estimated to prevent 7170 (8288 undiscounted) outpatient visits due to all-cause acute otitis media, 5325 (6154 undiscounted) admissions due to all-cause pneumonia, 87 (100 undiscounted) admissions due to pneumococcal meningitis, and 508 (588 undiscounted) admissions due to pneumococcal non-pneumonia and non-meningitis (NPNM). In addition, the vaccine was estimated to prevent 41 (48 undiscounted) deaths. This is equivalent to approximately 5 deaths and 700 admissions prevented each year in Georgia. Over the 10-year period, PCV10 would cost the government approximately US$ 4.4 million ($440,000 per year). However, about half of this would be offset by the treatment costs prevented. The discounted cost-effectiveness ratio was estimated to be US$ 1599 per DALY averted with scenarios ranging from US$286 to US$ 7787. DISCUSSION: This study led to better multi-sectoral collaboration and improved national capacity to perform economic evaluations. Routine infant vaccination against Streptococcus pneumoniae would be highly cost-effective in Georgia. The decision to introduce PCV10 was already made some time before the study was initiated but it provided important economic evidence in support of that decision. There are several uncertainties around many of the parameters used, but a multivariate scenario analysis with several conservative assumptions (including no herd effect in older individuals) shows that this recommendation is robust. This study supports the decision to introduce PCV10 in Georgia