At present, electrochemical analysis methods are increasingly used to solve the problem of research on quantitative and qualitative indicators of organic substances. One of the most common electrochemical methods of analysis is conductometry. Along with the straight line, indirect conductometry is often used, in which the substances under analysis react with the corresponding components before the measurement, and the fixed change in electrical conductivity is determined exclusively by the presence of the products of the reaction that occurred. A necessary condition for the application of this method is the presence of ions in the reaction medium, and since the pectic substances are polyelectrolytes, this condition is met, which allows us to use the conductometric titration method to determine the quantitative and qualitative characteristics of pectic substances. The technique we propose relates to technical biochemistry, namely, to the determination of the amount of pectin substances in plant raw materials. We have prepared "standardized" solutions of fractions of pectin substances. Samples of solutions of fractions are taken. Saponification of fractions of pectin substances in the samples of the solutions under analysis is carried out with 2.5 ml of 40% NaOH solution. Fractions of the pectin substances are precipitated with 2.5 ml of concentrated HCl. The solutions to be analyzed are centrifuged in 50 ml test strips at a rotor speed of at least 5000 rpm for 5-7 min. Suspensions of pectin fractions with distilled water are suspended in a beaker for titration with a magnetic stirrer for at least 30 minutes. Conductometric titration of suspensions of precipitates of fractions of pectic substances is carried out with stirring. Based on the results of conductometric titration, graphs are plotted, according to which the volume of titrant consumed for titration of pectic acid is established. Calculation of the mass fraction of fractions of pectic substances is carried out according to the formula. The methodology is distinguished by the simplicity of implementation, which makes it possible to obtain accurate data at high convergence of parallel analyzes, and it saves labor and time costs at all stages of the process
The article presents two express-methods of multidetails
women’s dresses design, which allow to determine
the optimal size and form of the cut out details
depending on the way of clothes form shaping. Methods
are developed based on the Paco Rabanne’s fashions
analysis
THE BASICS OF CALCULATING THE PROBABILITY OF FAILURE-FREE OPERATION OF SUPPLY BUSES AND BUS SECTIONS
In agriculture, the high reliability of electricity supply is necessary because of its main feature production is associated with biological objects. The change in the state parameters can lead to a sharp decrease in the productivity of the biological system or, in general, to the death of it. The following enterprises are particularly critical to the reliability of power supply: dairy farms, hothouse complexes, incubators, grain storage sites, finished products and much more. The article presents: models of failure of switchable busbar, models of failure of supply buses; formulas for the calculation of reliability indicators, the calculated values of the probabilities of failure-free operation of individual elements, analysis of the values obtained, conclusions were made on the models presented and suggestions were made for introduction into production, energy conservation was associated with reliability of electrical installations
The article reveals the basic principle of stabilizing
the DC voltage, providing automatic control of
electrical devices and electrical equipment, control
systems, control and protection, etc. There are
functional diagrams (operated and promising) of DC
voltage stabilization with a device included in the
input and output power circuits of the rectifier, and a
new structural solution to a functional circuit of the
rectifier made of two controllable power electronic
devices and transformer with midpoint. The article
lists peculiarities of the circuits of the voltage
regulators and their main advantages and
disadvantages. We have reviewed functional
diagrams of existing and new solutions of the
stabilizers and the characteristics of their work; it
will increase the effectiveness of pre-project works
on the development of stabilizers of the DC voltage
with improved performance characteristics. This
article might be useful for post-graduates and
research workers who are involved in the
development of DC voltage stabilizers
A mathematical description of the potentials of mass-transfer of hygroscopic materials is possible on the basis of analytical expressions describing sorption and desorption isotherms. Because of the complex nature of the interaction of colloidal capillary-porous materials with moisture, determined by the action other than sorption forces (physical sorption, absorption, chemisorption), capillary condensation forces and osmotic forces, which for different materials are specific and quantitatively different, to date There is no single universal dependence for the analytical description of isotherms of sorption and desorption. Accordingly, there is a wide variety of analytical expressions for the description of isotherms of sorption and desorption. There are many different methods of analytical description of the sorption properties of colloidal capillary-porous materials. All known methods can be divided into two groups: the first should include analytical expressions derived theoretically on the basis of various hypotheses and assumptions, while the second - purely empirical based on the expansion or change in the forms of models of the first group. A large number of equations of equilibrium isotherms are mathematically equivalent. Thus, the method of determining the transport potential based on position allows us to take as a basis for calculation the experimental data on the hygroscopic properties of certain materials and to use the phenomenological approach for the engineering calculation of complex technical devices
The foodservice industry plays an increasingly
important role in modern society and every person.
This is achieved primarily due to the changing
technologies of food processing, development of
communications, the means of delivery of products
and raw materials, the intensification of many
industrial processes. Catering is one of the most
important socio-economic components of the level of
development of society. The production process
consists of the partial tasks of providing, storing,
manufacture, sale, distribution, financing, optimization
of the warehouse, personnel training and the
introduction of new technologies and management.
The aim of the study is determination of methodology
of optimization of procurement activities in the field of
restaurant business, using mathematical programming
methods. In catering should pay special attention to the
costs of procurement. When choosing a method of
solution you need to consider the shelf life of products
purchased, calculate the number of them required for
dishes and many other important criteria. Today there
are thousands of solutions to the optimization
problems of planning and management, but many of
them also have a number of disadvantages, for
example, do not cover all aspects of the subject area,
neither provide complete information
ANALYSIS OF QUALITY INDICATORS OF AUTOMATIC CONTROL SYSTEMS WITH NONLINEAR APPROXIMATION CONTROL LAW
The subject of research of this work was the study of
the quality of control processes in a nonlinear
automatic control system with an approximating the
control law. In the known published works there are
no results of such studies, which makes it difficult to
synthesis a nonlinear control system for multimode
objects in applied biotechnology, including
technological objects of the agro-industrial complex.
A comparative analysis of the quality of regulation in
the transient and steady-state regimes is carried out. It
is shown that the approximation method used for the
synthesis of the nonlinear control law provides a
linear dependencies in steady-state and close to them
modes in combination with relay modes in transient
regimes, which is a positive factor for improving the
quality of regulation in multimode control systems. It
does not necessary to determine the moments of
switching the dependencies in the control law when
changing modes
The article presents the main directions of the
application of the scree plot method in solving
metrological problems in the social and humanitarian
fields of knowledge (economics, pedagogy, sociology,
including sciencemetry). It is known that statistical
measurements in socio-economic systems are
inextricably linked with the processing of primary
homogeneous monitoring information. It is also known
that empirical averaging (computation of the empirical
mean), as the dominant method of mathematical
statistics, is becoming a thing of the past, due to moral
aging, inconsistency with modern requirements
(primarily to measurement results in socio-economic
systems); In science meteorology, this method was
replaced by the scree plot method (the Hirsch index
and other scientometric indicators are estimated on the
basis of this method). Despite its enormous potential,
the scree plot method, as an alternative to traditional
methods of mathematical statistics, is very poorly used
in the social and humanitarian fields of knowledge.
The authors of this article have shown that this method
can be successfully applied in solving various
metrological tasks, not only in science (sciencemetry is
a branch of science), but also in economics, pedagogy
and sociology. In addition, the authors show
modifications of the scree plot method, using the
example of measuring (measuring) indicators in the
economy, sociology and pedagogy; The relationship
between the scree plot method and the theory of latent
variables (qualimetry) and database technology is
grounded. The authors also substantiate that the scree
plot method - the basis for the formation of monitoring
indicators that adequately reflect the performance of
socio-economic systems. The practical significance of
the results of this study is that they can be used in
socio-economic and psychological-pedagogical
monitoring systems (according to modern views,
monitoring is an information management
mechanism). Methodological basis of the research:
system, sociological, competence, probabilitystatistical
and qualimetric approaches (leading
methodological basis is the probabilistic-statistical
approach). Research methods: modeling; Methods of
graph theory, sets and relations; Systemic-cognitive
analysis; Methods of qualimetry (the theory of latent
variables); Methods of mathematical statistics
There are three main growth points of modern information technologies: global network and mobile communication, advanced human-machine interfaces, intelligent technologies. As it is known, the system (synergistic) effect is usually observed in multidisciplinary and interdisciplinary researches. This means that an interesting direction of research and development is located at the overlap of these three promising areas, namely: advanced interfaces in the global mobile networks, advanced intelligent interfaces and the application of artificial intelligence technologies in the Internet and mobile communications. In addition, a particularly high relevance goes to the development and application prospective of intelligent interfaces to the Internet and mobile communications. The Internet intellectualities gradually, it turns from non-local storage of large data (big data) in information space that contains meaningful big data, i.e. "great information" (great info), and then in the space of knowledge or "cognitive space" in which most information is actively used to achieve goals (management) and turns into the "great knowledge" (great knowledge). There are more sites devoted to artificial intelligence, free databases for machine learning (UCI, Kaggle, and others) and even on-line intelligent applications, and interfaces used in the Internet are improving. Recently, there was an acquisition of company Oculus, which is the world's leading developer and manufacturer of ammunition of virtual reality by the developer of one of the first global social networking Facebook - Mark Zuckerberg. However, students and scientists still do not notice that open, scalable, interactive, intelligent on-line environment for learning and researches already exists and operates, based on automated system-cognitive analysis (ASC-analysis) and its programmatic Toolkit – intellectual "Eidos" and the author's website. This article is an original presentation and it is designed to familiarize potential users with the capabilities of this environment
A computer program, as an information system, is designed to fill in the daily form that simulates the form of SP 20. This document indicates the number of livestock, the feed consumption limit by species and sex and age groups per head and the total limit for a month for all livestock. The computer program is created on the basis of an Excel spreadsheet, which is easily mastered by the user (accountant, accountant, manager). The computer program is developed using the VBA language, which allows you to automate all computing operations for data processing. The user enters only known initial data (cattle groups, species and number of feeds)