Development of Methods and Algorithms for Spectral Data Analysis for Vibroacoustic Diagnostics of Diesel-Generator Sets at NPPs

In this article, the main methods and algorithms for spectral data analysis for vibroacoustic diagnostics of diesel-generator sets at nuclear power plants are considered. To collect the diagnostic data, an experimental setup was developed, thanks to which the sound signals of the diesel generator were obtained under various operating conditions. The recording and processing of signals was carried out using the application package and MATLAB programming language. The article describes the application of correlation and spectral analysis for data processing and analysis. Also, the authors apply regression analysis to find the dependence of the speed of the diesel engine on the frequency of acoustic oscillations. The prediction of the number of revolutions from the frequency of sound vibrations makes it possible in the future to build a more accurate mathematical model of engine operation, and also to find diagnostic features for detecting malfunctions and anomalies in the operation of a diesel generator

Phase diagram of 2D array of mesoscopic granules

A lattice boson model is used to study ordering phenomena in regular 2D array of superconductive mesoscopic granules, Josephson junctions or pores filled with a superfluid helium. Phase diagram of the system, when quantum fluctuations of both the phase and local superfluid density are essential, is analyzed both analytically and by quantum Monte Carlo technique. For the system of strongly interacting bosons it is found that as the boson density $n_0$ is increased the boundary of ordered superconducting state shifts to {\it lower temperatures} and at $n_0 > 8$ approaches its limiting position corresponding to negligible relative fluctuations of moduli of the order parameter (as in an array of "macroscopic" granules). In the region of weak quantum fluctuations of phases mesoscopic phenomena manifest themselves up to $n_0 \sim 10$. The mean field theory and functional integral $1/n_0$ - expansion results are shown to agree with that of quantum Monte Carlo calculations of the boson Hubbard model and its quasiclassical limit, the quantum XY model.Comment: 7 pages, 5 Postscript figure

Josephson array of mesoscopic objects. Modulation of system properties through the chemical potential

The phase diagram of a two-dimensional Josephson array of mesoscopic objects is examined. Quantum fluctuations in both the modulus and phase of the superconducting order parameter are taken into account within a lattice boson Hubbard model. Modulating the average occupation number $n_0$ of the sites in the system leads to changes in the state of the array, and the character of these changes depends significantly on the region of the phase diagram being examined. In the region where there are large quantum fluctuations in the phase of the superconducting order parameter, variation of the chemical potential causes oscillations with alternating superconducting (superfluid) and normal states of the array. On the other hand, in the region where the bosons interact weakly, the properties of the system depend monotonically on $n_0$. Lowering the temperature and increasing the particle interaction force lead to a reduction in the width of the region of variation in $n_0$ within which the system properties depend weakly on the average occupation number. The phase diagram of the array is obtained by mapping this quantum system onto a classical two-dimensional XY model with a renormalized Josephson coupling constant and is consistent with our quantum Path-Integral Monte Carlo calculations.Comment: 12 pages, 8 Postscript figure

Design Features of Multistage Centrifugal Compressor of Vapor Refrigerating Machine with Complete Working Fluid Intercooling

© 2017 The Authors. Published by Elsevier Ltd. The work sets out the distinctive features of the method of gas-dynamic calculation of multistage centrifugal compressors for refrigerating machines running on a cycle of multi-stage compression of working fluid with its complete intercooling between the stages. The parameters of width of specific sections of the impellers, diffusers, and reverse guide vanes as well as the operating parameters during polytropic compression and parameters of the inner power of the compressor were corrected. The research outcomes can be used in the design of centrifugal compressors for refrigerating machines operating at the specified cycle

Representations of (2,n)(2,n)-semigroups by multiplace functions

We describe the representations of $(2,n)$-semigroups, i.e. groupoids with $n$ binary associative operations, by partial $n$-place functions and prove that any such representation is a union of some family of representations induced by Schein's determining pairs.Comment: 17 page

Comparative pharmacoeconomic analysis of Paclical® and Taxol® in Russian Federation

Ovarian cancer is a severe oncological disease, characterized by relatively late detection and unfavorable course leading to significant mortality among affected patients. One of the most well-proven treatment strategies is combination of taxanes such as Paclitaxel with platinum compounds. Unfortunately physicochemical properties of Paclitaxel (Taxol®) necessitate using it with an expensive, highly allergenic and hard to manage emulsifier that requires an extensive premedication regime before administration. A recently developed technology for micronizing Paclitaxel has allowed to create a new drug form, Paclical®, which allows to carry out chemotherapy without a need for complex premedication and specialized infusion systems. Available randomized clinical trial data indicates that Paclical® is not inferior to Taxol® in terms of safety and efficacy. Since taxanes are in high demand in oncology, it appears worthwhile to carry out a pharmacoeconomic comparison of Paclical® and Taxol®, which is the subject of current research effort. Aim. To perform the pharmacoeconomic analysis of Paclical® and Taxol® as adjuvants for Carboplatine for patients with recurrent epithelial ovarian cancer within context of Russian Healthcare. Methodology. This PHe is conducted perspective of public health organizations of the RF at federal and national levels, as well as from general social interest perspective. A complex PHe model consisting of a “decision tree” (to model treatment proper) and a Markov model (to model survival without progression over timespan of 12 months) was constructed. Cycle length for the Markov component of the model was set at 1 month. Two groups composed of 1000 patients each was simulated, each receiving one of the investigated drugs in combination with carboplatine, as well as full set of diagnostic and therapeutic interventions as outlined in relevant Russian standards. Randomized clinical trial dedicated to safety, tolerability and efficacy of the investigated compounds was used as data source. Direct medical costs in each simulated group were estimated using existing standards. Indirect costs including GDP loss and disability payments were also accounted for. Cost-effectiveness analysis, Cost-minimization analysis, Budget impact analysis, pharmacoeconomic expediency assessment and sensitivity analysis were performed. Result. Cost-minimization indicator for Paclical® was determined to be -3 544 819 rub., indicating reduction of direct costs when using this drug. Paclical® also dominated in terms of CER (259 703,5 rub. for Paclical® and 306 852,6 rub. for Taxol®), and since use of Paclical® was associated with both increased effectiveness and cost reduction, ICER calculation was not necessary. Overall number of patients surviving without progression at 12-month mark was used as efficacy criterion. Budget impact analysis has found that Paclical® is associated with reduction of budgetary burden, specifically a 3,6% saving that corresponds to 130 919 rub. per 100 000 of population (adjusted for ovarian cancer incidence). Pharmacoeconomic expediency assessment indicated that both drugs are acceptable for purposes of drug reimbursement system but Paclical® is somewhat more appealing due to wTP/CER indicator of 5,7 (with Taxol® having 4,8). Sensitivity analysis has confirmed the robustness of these findings Conclusion. Use of Paclical® is associated with higher healthcare resources utilization efficiency due to Paclical®’s domination in terms of CER indicator, as well as direct cost reduction of 3 544 819 rub., better absolute progression-free survival at 12-month mark, and reduction of budgetary burden by 3,6% per 100 000 of population. Both drugs being investigated are acceptable as part of drug reimbursement system but Paclical® is slightly more attractive. Thus, use of Paclical® in Russian oncological patients with ovarian cancer appears highly expedient

Pharmacoepidemiological studies: methodology and regulation

This article describes the methodology of pharmacoepidemiological studies that help to research the efficacy and safety of drugs in real clinical practice at the level of a population or large groups of patients, promoting the rational and economically acceptable use of the most effective and safe drugs

Quantum orientational melting of mesoscopic clusters

By path integral Monte Carlo simulations we study the phase diagram of two - dimensional mesoscopic clusters formed by electrons in a semiconductor quantum dot or by indirect magnetoexcitons in double quantum dots. At zero (or sufficiently small) temperature, as quantum fluctuations of particles increase, two types of quantum disordering phenomena take place: first, at small values of quantum de Boer parameter q < 0.01 one can observe a transition from a completely ordered state to that in which different shells of the cluster, being internally ordered, are orientationally disordered relative to each other. At much greater strengths of quantum fluctuations, at q=0.1, the transition to a disordered (superfluid for the boson system) state takes place.Comment: 4 pages, 6 Postscript figure

Clinical and economic aspects of the use of OneTouch glucose meters for the screening of diabetes mellitus

Diabetes is increasingly widespread in the Russian Federation. It is a severe chronic disease that both independently reduces quality of life and causes exacerbation of other pathologies. This makes evaluation of quality of diabetes management and understanding of clinical and economic properties of various technologies used to screen blood glucose levels, including portable blood glucose meters. Previously there already were clinical-economic evaluations of blood glucose meters within context of Russian Federation but they have not included modern high-precision equipment, thus ensuring attractiveness of current research effort into HTA of modern blood glucose meters that accounts for real life hospital practice. Goal. To assess the clinic-economic properties of modern blood glucose portable measurement systems of OneTouch family and the real-world practics of their use in Russian healthcare facilities. Methodology. The research was performed from the perspective of the Russian healthcare system. Target population was represented by a virtual cohort of 100 patients. Only direct costs were accounted for, specifically all costs caused by consumables involved in operating multifunctional laboratory complexes and all consumables involved in operating portable glucose meters. Employee salaries were also included (accounting for number of personnel involved in different procedures as based on a real clinical practice survey performed as part of this research). Since it is known that modern, standard-compliant portable glucose meters have an accuracy that is more than sufficient for routine screening, cost minimization analysis was used for assessment of economic effects when comparing different approaches to organizing glucose level screening. Research results. The survey during this research effort has indicated that not all medical facilities utilize “tandem usage” of multifunction laboratory complexes and portable glucose meters, however, such “tandem use” is the most widespread approach to organizing blood glucose screening. Cost minimization analysis has demonstrated that “tandem usage” is also the most economically attractive approach and results in cost savings for the medical facility. Conclusions. Current research effort which included cost analysis and cost minimization analysis has demonstrated that “tandem usage” approach which involves combined use of both multifunction laboratory complexes and portable glucose meter systems has substantial economic advantage (over 60 % for analysis with 5 year time horizon). Multiple sensitivity analyses have confirmed robustness of this result. This research further establishes the importance of communicating advantages of modern portable glucose meters to healthcare organizers since this technology is not only clinically rational but also economically optimal