The steady increase in demand for isotopes requires the
development of methods to increase the efficiency of
isotope separation technologies. Methods of isotope
separation based on thermodynamic differences of
isotopic forms of the molecules don't require significant
investment, but characterized by a low rate of exchange.
It's known that the magnetic effect leads to a change the
vibrational frequency of the molecules, and therefore
their thermodynamic parameters. The change increases
the thermodynamic parameters, including the exchange
rate. The results of the experimental determination of the
thermal effect of dissolving the salts of NaCl, KCl,
CuSO4, sodium amalgam decomposition by distillate in
a magnetic field and without field were shown. Magnetic
interference can have a significant effect on the amalgam
exchange method which was shown by quantum and
mechanical analysis of the results
In this article we propose a method of determining the share or the significance (weight) of indicators of Beaver and risks R in the portfolio formed by these parameters allowing us to minimize the mean square error evaluating the effectiveness of the portfolio (risk) in the assessment of the financial condition of the companies investigated. The proposed method is the minimization of a quadratic form in variables satisfying lengthy conditions, i.e. the quadratic programming. This technique is implemented using four methods of optimization: analytical method, using built-in function minimization block given, the penalty function method and the gradient method. More so, this technique allows, as shown by the results of the computational experiments, the expert without routine statistical data processing to obtain additional information on the credit worthiness of the investigated enterprise and make a more informed conclusion about its financial condition, which speeds up the decision on granting a loan required by a company. Based on the techniques proposed in this paper, other techniques of assessing the creditworthiness of businesses may be constructed using the results of optimization theory based on well-established applied research methods: Method of evaluating the creditworthiness of Russia, Credit scoring method, the American method, method of Altman and others
The article presents a mathematical model of the ion transport across phase boundary exchange membrane / solution. The border is considered as an object in space, endowed with all the physical and chemical properties that are inherent physical and chemical phases. It is regarded as a special physical and chemical environment, having a distributed exchange capacity in which there is space charge dissociation of water molecules. The size of this object is estimated in the range of 1-300 nm. The surface morphology of industrial membrane type MK-40, ÐœA-41 and ÐœA-41P was investigated experimentally by scanning electron microscopy (REM). There was analyzed the amplitude of average surface roughness. In this article, the reaction layer is modeled as a region that forms as a relief morphology of the membrane. Membrane properties are due to the properties of the solution and the properties of the membrane. To determine the dependence of Q(x) is proposed procedure for assessing the proportion of solid phase in the total volume of which can be seen in the vertical cross section microprofile on the membrane surface line. Height multivendors determine the reaction layer zone on frame of model. Influence of surface morphology on the V-A characteristics and the sizes of the convective instability of cation-exchange membrane evaluated numerically simulating the hydrodynamic flow conditions using a solution of the Navier-Stokes equations. The transfer of a strong electrolyte such as NaCl ions through the thin layer of the reaction layer is considered. The place of nanomodel in the structure of a three-layer membrane system is showed. The distribution of the concentration of ions in the system, the charge density distribution and the dependence of the integrate charge with extent nanolayer is present. How to change the shape of the space charge and its integral value with one is investigated
The results of the research of the influence of tellurium dopant on the opto-electrical properties of the GaxIn(1-x)PySb(1-y) , are reviewed in this article. The mostly important results are discussed
A simple climate–economic model based on the AK model of economic growth with the endogenous depreciation rate linear in temperature and on the exogenous climate scenario with temperature linear in time is considered. The analytical solution of the model is obtained. The uncertainty of temperature projections is introduced in the model, and the moments of model state variable are calculated analytically. Numerical examples are provided
In this article we consider a mathematical model of effect of non-compliance with the prevention of HIV/AIDS among a heterogeneous population based on known model by Kimbir et al (2006). The effectiveness of a condom use and implications of non-compliance with a population of preventive measures (condoms) are the aim of this research work. In this work, with definite coefficients, nonlinear model is used, which consists of system of six differential equations for different population groups (six groups of the population) to obtain the model equations. Compared with the existing model by Kimbir, the proposed model to a large extent, takes into account the birth rate of the studied population. Numerical simulation of the model equations shows that reducing the rate of transmission of HIV/AIDS can be effectively achieved within a certain time, and only where relatively high condom efficacy and high compliance by susceptible and infected are observed. From the obtained results, we can see that the control of HIV/AIDS in the heterosexual population depends on the net compliance and effectiveness of the recommended prevention (condom use). As a recommendation, the model focuses on intensive training and ongoing campaigns to raise the awareness of the population by governmental and non-governmental agencies on the effective use of the condom
This article discusses the mathematical and numerical modeling of the immune system of the course of HIV infection without treatment. Presently a significant number of scientific papers are devoted to the study of this problem. However, HIV infection is highly volatile and there is no effective drug, in that HIV has the ability to mutate and reproduce itself in the presence of chemical substances that are meant to inhibit or destroy it. The mathematical models used in this paper are conceptual and exploratory in nature. The proposed mathematical model allow us to obtain a complete description of the dynamics of HIV infection, and also an understanding of the progression to AIDS.
Thus, the results of the numerical solution of differential equations in this work show that: the disease develops, and at low concentration of the virus, a certain level of stability does not depend on the initial concentration of infestation. In the absence of treatment, for interesting competition between virus and the loss of virus caused by immune response should be strictly greater than the rate of multiplication of the virus in the blood; the reproduction rate of the uninfected cells should be stricly greater than the mortality rate of the uninfected cells
The purpose of mathematical statistics is
development of methods for the data analysis
intended to solve applied problems. Over time,
approaches to the development of data analysis
methods have changed. A hundred years ago, it was
assumed, that the distributions of the data have a
certain type, for example, they are normal
distributions, and on that assumption they developed
a statistical theory. The next stage, in the first place
in theoretical studies there are limit theorems. By
"small sample" we mean a sample, which can not be
applied to conclusions based on the limit theorems.
In each statistical problem there is a need to divide
the final sample sizes into two classes - those for
which you can apply the limit theorems, and those
for which you can not do it because of the risk of
incorrect conclusions. To solve this problem we
often used the Monte Carlo method. More complex
problems arise when studying the effect on the
properties of statistical procedures for data analysis
of various deviations from the original assumptions.
To study such impact, we often used the Monte
Carlo method as well. The basic (and not solved in a
general way) problem of the study of the stability of
the findings in the presence of deviations from the
parametric families of distributions is the problem of
choosing some distributions for using in modeling.
We consider some examples of application of the
Monte Carlo method, relating to the activities of our
research team. We have also formulated basic
unsolved problems
The article discusses the Riemann's unified field theory and its extension in 6D in general relativity. It is shown that in 6D there are possible movements on two spherical areas in the form of nonlinear waves
The article presents a model for choosing a variety of
alternative solutions, in which we have a subset of
turns or more alternative options, based on the use of
the Bayesian approach, based on the formulated
concept of security functions as a priori estimate of the
effects of the decision. This reduces the projected
parameters and, therefore, increases the values of
security. Thus, the considered indicators of data
protection reflect the essence of Bayesian approach to
decision making and management of GIS, so it allows
to generate optimal decision rules