Method for determining the mass of evaporated water during thermal regulation in artificial agroecosystems

We noted the need for the use of digital technologies in crop production, i.e. we need to develop a special software. As we know any software implies that processes and functions are presented in an analytical form. Photosynthesis most efficiently (at the maximum rate) proceeds at a certain temperature, which is provided by thermoregulation using a self-organizing process of evaporative cooling (SOPEC). This process accounts for more than 90% of all water consumed by the plant. It is noted that the water needs of a plant will be determined by the SOPEC, since the relationship between the main energy factors – photosynthesis and thermoregulation – is reduced to the SOPEC functioning. The analytical determination of the mass of evaporated water plays a key role in the development of a digital moisture supply system and its software. The derivation of the analytical expression is based on the determination of the thermal component of light radiation energy by the method of graphical integration of the spectral distribution of the intensity of this radiation. The obtained expression allowed determining the mass of the evaporated liquid during thermoregulation. The result obtained was verified experimentally by taking the calculated value of the evaporation mass and comparing it with the experimental results. A test showed that the experimental weight slightly, i.e. by 4%, differs from the calculated weight.

ANALYSIS OF THE GENETIC DIVERSITY IN MAIZE LANDRACE CULTIVARS FROM NORTHERN RIO GRANDE DO SUL, BRAZIL

Maize landraces are important genetic resources for maize breeding. Many of these landrace varieties have not yet been properly studied in order to be distinguished from the others. In this study, multivariate statistical methods were used, beyond the analysis of variance, for estimating genetic dissimilarity among 27 maize landrace accessions. Principal component analysis and clustering analysis were performed using 16 evaluated quantitative characters. The ANOVA results reported the existence of significant differences among the tested accessions for 14 evaluated characters. Two principal components almost explained 49% of found experimental variance. Four different clusters were formed by the used clustering analysis, whose results were plotted into a dendrogram. The graphical integration of this dendrogram with the PCA allowed to conclude that the variation found may be due to the genotypic distinctions existing among the four groups of accesses determined in this study.

The teaching of graphical calculus in engineering schools (1860-1970)

Graphical calculus is the part of numerical calculation that is based on geometrical constructions. It was established as a subject of knowledge and teaching from the 1860s onwards. With its three specialized components, graphical statics, graphical integration and nomography, it was a response to the growing calculation needs of engineers at the time of the industrial revolutions and the development of communication channels. It then became progressively obsolete in the 1960s due to the increasing role of computers and electronic calculators. The aim of the present contribution is to examine the content of graphical calculus courses created in engineering schools and universities between 1860 and 1960. Through a quantitative study of the treatises intended for the teaching of graphical calculus, we will also attempt to analyse, both chronologically and geographically, the diffusion processes of this teaching in Europe and the rest of the world during the period under consideration. Keywords: history of mathematics, mathematics education, mathematics of engineers, graphical calculus, graphical statics, graphical integration, nomography

A comparative analysis of the most common deterministic methods for the calculation of electricity losses in industrial networks

: The work is devoted to the analysis of deterministic most common methods for determining electricity losses in low-voltage industrial power supply networks. The method of graphical integration, the method of calculating electricity losses using the maximum loss time, the method of determining losses by time 2t, the method of calculating electricity losses by the average node loads are considered. The features of the application of each method are revealed. It is shown that for the method of graphical integration, initial data on the dependences of load schedules for each network element are required, and the method of calculating losses by average node loads can be used in networks with relatively constant loads. We consider the methods of calculating the losses based on graphical integration, the time of largest losses, 2t and the root-mean-square loads.At the same time, the errors of the considered methods for calculating electricity losses can be due to such reasons as the neglect of the heating temperature of the conductors, the neglect of the resistances of the contact connections of switching devices, the inaccuracy of determining the values of losses during the highest and lowest power demand, the inaccuracy of determining the time of the largest losses,. disregarding the form of the load schedule of consumers.Using the example of an industrial radial network site with known load graphs of consumers, the electric power losses in the circuit lines with the specified methods were calculated with the determination of the error of each method and the identification of the causes of errors. In this case, the method of graphical integration was adopted as the reference method of calculation. As a result of the calculations, it was established that the method of calculating 2t has the smallest error. It is shown that when choosing a method for determining electricity losses, it is necessary to observe the condition of compliance with methodological and informational errors.

METHODOLOGICAL PRINCIPLES OF EVALUATION OF INVESTMENT ATTRACTIVENESS OF THE ENTERPRISE

The purpose of the research is a complex of theoretical and applied provisions on the formation, evaluation, and improvement of the methodology of evaluation of the investment attractiveness of enterprises. Methodology. In the process of research, the following methods were used: methods of comparison, analysis and synthesis is used in determining the features of conceptual approaches to the concept of investment attractiveness of an enterprise and the formation of the author’s definition of this category; method of diagnostic evaluation is used in the evaluation of existing models for analysing the investment attractiveness of enterprises; method of expert evaluation is used for the building of flexible limits of levels of investment attractiveness of the enterprise; methods of system and structural analysis is used for developing the basic elements and the general structure of the model of interpretation of the method of graphical integration; the method of graphic integration is used within the construction of graphs of investment attractiveness of enterprises A and B. The aim of the study is to justify of the approach to create a model that can justify of the feasibility of investing and determine the factors and conditions of investment attractiveness of the enterprise for different participants of the investment process. The findings of the study. The results of the research suggested an improved definition of the concept of investment attractiveness of the enterprise, which took into account the following disadvantages of existing approaches to the present essence of the concept: the investment attractiveness of the enterprise is often associated with the system of financial and economic indicators of the activity of enterprise, while not taking into account also an important social and psychological factor, since the very name of the term “investment attractiveness of the enterprise” includes the social-psychological element in the form of the concept of “attractiveness”, which is widely used in economic literature; the subjective view of the potential investor on the fact that the object being considered for investing to satisfy the investor’s expectations regarding the economic or social effect is significant. This aspect is key in determining of concept of investment attractiveness of the enterprise, when choosing an investor of an enterprise to invest its capital for the purpose of investing; it is necessary to achieve consistency and symbiosis between the evaluation of financial and economic, socio-psychological, industrial, innovative, environmental and other factors, which in the complex form the investment attractiveness of the enterprise; using the expression “high level of profitability on investment with minimal risks” is partially incorrect in some definitions of the investment attractiveness of the enterprise since obtaining high profits involves a certain level of risk and each investor knows about this; the importance of increasing the investment attractiveness of the enterprise has the level of involvement of innovation in the activities of the enterprise in the frames of use of investment capital; the targeting of almost all definitions only on high financial and economic indicators, which, depending on the situation, are not always correct. A complex system of indicators for evaluation of the investment attractiveness of an enterprise is proposed, consisting of six groups of indicators (market position, property complex, profitability, financial stability, risks, innovative potential), each of which includes six coefficients determining the level of investment attractiveness for this group. The features and advantages of this system of indicators are: complexity and complementary to standard methods with indicators of the level of investment risk and innovative potential of enterprises; standardization of indicators; unidirectionality of indicators; Flexibility of the recommended limits for each coefficient. The method of graphical integration of the investment attractiveness of the enterprise, which has several advantages over other methods, proposed in the scientific literature, is offered because: it is a combination that includes the advantages of an integral method, as well as a market, and partially matrix method; it allows quantifying various aspects of economic activity of the enterprise by the elementary calculation of a certain number of coefficients; it does not require significant time to spend on the evaluation; it has a mathematical justification since the final indicators for comparing the investment attractiveness of several enterprises are calculated using the numerical integration method; it has the flexibility of determining the level of investment attractiveness of an enterprise by incorporating into the methodology in accordance with the socio-psychological component of the concept of investment attractiveness and the interests of the investor; gives a visual interpretation of the results of investment attractiveness assessment.

Bipartite Graphical Integration of Dielectrophoresis Process Models for Assembly of Carbon Nanotubes

Dielectrophoresis is the process where nonuniform electric field causes the translational motion of uncharged, polarized particles. Recently dielectrophoresis has become the most widely used process in the field of nanomanufacturing as the translational motion of a carbon nanotube caused by the dielectrophoresis assembles it in the spacing between the electrodes. This process enables engineers to replace the traditional metal (copper or aluminum) wire with carbon nanotubes (CNTs) in the miniature electronic devices. Various process models have been developed and parametric studies have been carried out to understand the process better and to improve the quality and reliability of assembly of CNTs. We consolidate the scattered knowledge of the dielectrophoresis process and represent the integrated knowledge in the form of a complex network by connecting the process parameters based on the relationships they shares. We find that the bipartite relationships exist between some of the process parameters and we represent them in the form of bipartite graphs. We also represent these graphs as incidence matrices and verify whether each graph fulfills the condition of being bipartite. We apply the shortest path algorithm to find an even length path between the any two process parameters which turns out to be an efficient method to estimate the unknown state variables of the process and to access the real time state of the assembly process quickly and efficiently. One can also use bipartite graph to identify the non-contributing variables and eliminate the over constraint situation by applying Gauss elimination method.