Classification of geokhod units and systems based on product cost analysis and estimation for a prototype model production

The paper considers data systematization on a new shield-type heading machine - geokhod. The target of the paper is to classify geokhod components on the basis of their technical and economical production parameters. A prototype model reveals the structure of a geokhod as an assembly unit and identifies its basic characteristics. The paper overviews the methods of product cost estimations, justifies the application of an operation-based approach for a prototype model, provides the results containing product cost data for various geokhod components and technological processes, and gives the data for a material cost structure. Taking into consideration the product cost analysis, geokhod components are classified according to their technical and economical production parameters. Moreover the paper outlines the ways of a classification application for a geokhod manufacturing techniques improvement

Criteria for climatic applicability of modern window types

Currently, the assignment of the required values of the technical and operational windows characteristics (such as resistance to heat transfer, air permeability, sound insulation, etc.) is carried out based on the technological capabilities of the window industry, and not on the basis of scientifically substantiated requirements for ensuring the microclimate and energy buildings efficiency in the design practice of most countries (as it happens in the case of external walls which are in almost identical operating conditions with windows, for example). One of the most common types of windows in modern construction practice are single windows with insulated glass units and profiles made of PVC and aluminum alloys. They were originally developed for operation in Western Europe where they have proven themselves well over many years of operation. However, their widespread use in the climatic conditions of the Russian Federation and the countries of Eastern Europe showed a number of problems during operation which is expressed in a decrease in the technical and operational characteristics of windows due to temperature deformations of their profile elements. This circumstance testifies to the limited area of application of these structures in terms of climatic conditions. The authors of the work introduce the concept of “climatic applicability of windows” in order to determine the rational application areas of types of windows which would ensure the fulfillment of the specified requirements for the comfort of the microclimate of the premises in any operation period of the building. Based on the results of the analysis of the work of third-party researchers and the authors own works the authors have determined a set of criteria for the climatic applicability of modern types of windows based on winter operating conditions. Promising areas for further research were considered

ASSESSMENT OF THE CURRENT STATE OF THE AGRICULTURAL STRUCTURE OF ARGENTINA

Background. Argentina is one of the largest and most developed socio-economic countries in Latin America. The use of modern agricultural technologies in the Argentine plains and new methods of shipping allowed Argentina to start exporting agricultural products to Europe. A series of commodity booms enriched Argentina and made it one of the largest economies in the world at the beginning of the 20th century. Purpose is to analyze and identify problems and prospects for the development of the agricultural structure in Argentina. Materials and methods. In the study, the authors used analytical materials of the UN Economic Commission and other international organizations on the countries of Latin America, reviews and reports of the Central Bank, the Institute of Statistics, the Ministry of Economy and Public Finance, the Ministry of Foreign Affairs. In this work, dialectical, systemic, historical, logical, formal-legal, comparative research methods were used. Results. Due to the abundance of appropriate land and natural resources, the favorable climate in most of the country and the generally low activity of pests, agricultural in Argentina is not particularly limited by natural conditions. However, there are a number of other factors that prevent Argentine farmers from fully operating as efficiently as possible. Conclusion. Argentina’s agro-industrial policy is quite contradictory. Despite the development of digital services and modern information technologies to support agricultural producers, the introduction of progressive export support programs, a fairly powerful infrastructure throughout the entire production cycle of agricultural products, the Argentine government from time to time resorts to using serious export barriers to maintaining the domestic market, which in general affects the Agar sector is not always positive

Lie Symmetries of Fundamental Solutions to the Leutwiler-Weinstein Equation

In this article, we study Lie symmetries to fundamental solutions to the Leutwiler-Weinstein equation Lu:=Δu+kxn∂u∂xn+ℓ(xn)2u=0 in the upper half-space ℝ+n. Starting from the infinitesimal generators of the equation Lu = 0, we deduce symmetries of the equation Lu = δ(x − x0), and using its invariant solutions, we construct a fundamental solution. As an application, we study a Green functions of the operator in the hyperbolic unit ball.publishedVersionPeer reviewe

Engineering Method for Calculating Temperature Deformations of PVC Window Profiles with a Reinforcing Steel Core

In current engineering practice, static calculation of windows for temperature loads is not performed. However, the existing experience in operating PVC windows in environmental conditions of Eastern and Northern Europe shows that the temperature deformation of such structures can reach values comparable to those of wind loads, which leads to a significant reduction in their technical and operational characteristics. Temperature deformations of windows can be assessed during laboratory tests. However, such tests are not representative. In this regard, it is necessary to develop an engineering method for calculating temperature deformations of windows. In this study, the authors present the results of the analysis of temperature deformations of PVC window profiles. The investigations were divided into several stages. First, the authors numerically analysed the character of temperature distribution over the cross section of PVC window profiles. Then, they theoretically substantiated the bending deformations of PVC window profiles disregarding the reinforcing steel core. Next, the authors considered the patterns of bending deformations of PVC window profiles, taking into account the presence of a reinforcing steel core in various schemes of their connection to each other. The authors also analysed the effect of the temperature dependence of the mechanical properties of PVC on the deformation of window profiles. The character of torsional temperature deformations of PVC window profiles was also studied. As a result of this investigation, the authors proposed a simplified analytical and numerical method for calculating the temperature deformations of PVC window profiles with a reinforcing steel core. The authors have used the proposed methods to calculate the temperature deformations of PVC window mullions (vertical bars that divide the window into parts). These theoretical calculations were compared with the experimental investigations data on PVC windows and showed a fine precision of results (the discrepancy was 10.6%)

СОВЕРШЕНСТВОВАНИЕ ОБОРУДОВАНИЯ ДЛЯ СОЗДАНИЯ НОВОЙ, БОЛЕЕ ЧИСТОЙ ТЕХНОЛОГИИ ПОДГОТОВКИ ДРЕВЕСНОВОЛОКНИСТОЙ МАССЫ

The aim of this study was to identify patterns of influence of the grinding blades of different geometrical performance on quality indicators of wood semi-finished products.The object of study of this work is the production of wood-waste fiberboard, the subject of research – physical phenomena and processes that characterize the process of secondary wood-processing semi-finished products.According to the results of laboratory and testing carried out statistical and mathematical analysis using a combination of advanced complementary physical, statistical and mathematical methods of research, as well as laboratory and field tests.The paper presents the results of a study of preparation of wood waste from the sliding table machines with different geometry of the grinding blades; assessment of morphological characteristics and properties of semi-finished wood-finished boards.Based on the results of studies built statistical and mathematical equations and constructed response functions clearly represent the investigated dependence and adequately describe the process under study.Scope: production of hardboard wet.Целью настоящих исследований явилось выявление закономерности влияния размольных ножей различного геометрического исполнения на качественные показатели древесноволокнистых полуфабрикатов.Объектом исследования настоящей работы являются древесноволокнистые отходы производства ДВП, предметом исследования – физические явления и процессы, характеризующие технологический процесс обработки вторичных древесноволокнистых полуфабрикатов.По результатам лабораторных и производственных испытаний выполнен статистико-математический анализ с использованием комплекса современных взаимодополняющих физических, статистико-математических методов исследований, а также лабораторных и производственных испытаний.В работе представлены результаты исследования подготовки древесноволокнистых отходов от форматно-обрезных станков с использованием различной геометрии размольных ножей; оценка морфологических характеристик древесноволокнистых полуфабрикатов и свойств готовых плит.На основании полученных результатов исследований построены статистико-математические уравнения и построены функции отклика, наглядно представляющие исследуемые зависимости и адекватно описывающие исследуемый процесс.Область применения: производство ДВП мокрым способом

DFT Modelling of Molecular Structure, Vibrational and UV-Vis Absorption Spectra of T-2 Toxin and 3-Deacetylcalonectrin

This paper discusses the applicability of optical and vibrational spectroscopies for the identification and characterization of the T-2 mycotoxin. Vibrational states and electronic structure of the T-2 toxin molecules are simulated using a density-functional quantum-mechanical approach. A numerical experiment aimed at comparing the predicted structural, vibrational and electronic properties of the T-2 toxin with analogous characteristics of the structurally similar 3-deacetylcalonectrin is performed, and the characteristic spectral features that can be used as fingerprints of the T-2 toxin are determined. It is shown that theoretical studies of the structure and spectroscopic features of trichothecene molecules facilitate the development of methods for the detection and characterization of the metabolites