scholarly journals Heat Treatment of a Casting Element of a Through Clamp to Suspension of Electric Cables on Line Post Insulators

2016 ◽  
Vol 16 (3) ◽  
pp. 89-94 ◽  
Author(s):  
J. Pezda
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Structural Changes ◽  
On Line ◽  
Technological Quality ◽  
The Subject ◽  
Electric Cables ◽  
Selection Of ◽  
Energy Network

Abstract Heat treatment of a casting elements poured from silumins belongs to technological processes aimed mainly at change of their mechanical properties in solid state, inducing predetermined structural changes, which are based on precipitation processes (structural strengthening of the material), being a derivative of temperature and duration of solutioning and ageing operations. The subject-matter of this paper is the issue concerning implementation of a heat treatment process, basing on selection of dispersion hardening parameters to assure improvement of technological quality in terms of mechanical properties of a clamping element of energy network suspension, poured from hypoeutectic silumin of the LM25 brand; performed on the basis of experimental research program with use of the ATD method, serving to determination of temperature range of solutioning and ageing treatments. The heat treatment performed in laboratory conditions on a component of energy network suspension has enabled increase of the tensile strength Rm and the hardness HB with about 60-70% comparing to the casting without the heat treatment, when the casting was solutioned at temperature 520 °C for 1 hour and aged at temperature 165 °C during 3 hours.

Determination of integral indicators characterizing the possibility of accommodating the evacuated population in the territory of the Republic of Kazakhstan

2020 ◽  
pp. 154851292097028
Author(s):  
Yernar Zh Akimbayev ◽  
Zhumabek Kh Akhmetov ◽  
Murat S Kuanyshbaev ◽  
Arman T Abdykalykov ◽  
Rashid V Ibrayev
Keyword(s):  
Statistical Data ◽  
Armed Conflicts ◽  
Security Issues ◽  
Inaccurate Information ◽  
The Subject ◽  
The Republic ◽  
The Impact ◽  
Integrated Indicators ◽  
Selection Of

Studying the historical facts of past wars and armed conflicts and natural and man-made emergencies, today in the Republic of Kazakhstan one of the most important security issues is the preparation and organization of the evacuation of the population from possible dangerous zones, taking into account the emergence of new threats to the country’s security. The paper presents an algorithm for constructing universal scales of the distribution function of opportunities by types of support and rebuilding them into subject scales using display functions. The purpose of the paper is to determine the integral indicators characterizing the possibility of accommodation of the evacuated population and the impact on resources during relocation. On the subject scales of cities and districts of the region, indicators of the possibility of relocation of a certain amount of the evacuated population by types of support and indicators characterizing the impact on the district’s resources during resettlement of a certain amount of the evacuated population are determined. It was concluded that the use of integrated indicators allows the selection of areas to accommodate the evacuated population without the use of statistical data, in conditions of incomplete and inaccurate information. The presented method does not replace traditional methods based on classical methods of territory assessment by the level of life sustenance, but also allows their reasonable combination with the experience of specialists in this field, taking into account the incompleteness, uncertainty, and inconsistency of the initial data of the study area, which does not allow the application of existing methods.

THE CONCEPT, TYPES, TASKS AND THE NEED FOR THE USE OF URGENT INVESTMENT TOOLS OF CRISIS MANAGEMENT AT ENTERPRISES

2017 ◽  
Author(s):  
Oksana Yurynets ◽  
Keyword(s):  
Crisis Management ◽  
Economic Condition ◽  
Negative Impact ◽  
Negative Influence ◽  
Management Program ◽  
Management Tools ◽  
The Subject ◽  
Effective Development ◽  
Selection Of

Currently, many Ukrainian enterprises are in crisis. Getting out of this situation requires the use of various types of urgent crisis management tools, among which investment instruments play an important role. The purpose of this article is to form the theoretical basis for the use of urgent investment tools of crisis management at enterprises. It was found that the urgent investment tools of crisis management in the enterprise should be understood as ways of immediate (urgent) investment actions which are aimed at eliminating or reducing the negative impact of the crisis on the economic condition of the enterprise and ensuring its further effective development. These instruments are grouped according to the following characteristics: the environment in which the relevant instruments are formed and operate, the relation to the current owners of the enterprise, the effectiveness of implementation, the duration of the effect of implementing instruments, the urgency of their implementation, the areas of investment, the objectives of application, the duration of application, the types of financial and economic crises at the enterprise, the elimination (reduction) of the negative influence of which the corresponding tools are directed at, the subject of investment. It is established that the main tasks of using investment urgent tools of anti-crisis management at the enterprises are: selection of the best types of investment urgent tools of anti-crisis management; selection of the best variant of each type of urgent investment tools of crisis management; setting deadlines for the implementation of selected types and options for urgent tools of crisis management at the enterprise; determination of the optimal amount of total investments that should be invested in the implementation of the crisis management program at the enterprise, and the corresponding to this volume of the general list of investment urgent tools of such management; identifying the best sources of investment and establishing the best structure of investment in terms of these sources.

scholarly journals Effect of T6 Heat Treatment Parameters on Technological Quality of the AlSi7Mg Alloy

2016 ◽  
Vol 16 (4) ◽  
pp. 95-100 ◽  
Author(s):  
J. Pezda ◽  
A. Jarco
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Low Cost ◽  
Dispersion Hardening ◽  
Recycling Potential ◽  
Low Mass ◽  
Technological Quality ◽  
New Applications ◽  
Casting Design

Abstract Very well-known advantages of aluminum alloys, such as low mass, good mechanical properties, corrosion resistance, machining-ability, high recycling potential and low cost are considered as a driving force for their development, i.e. implementation in new applications as early as in stage of structural design, as well as in development of new technological solutions. Mechanical and technological properties of the castings made from the 3xx.x group of alloys depend mainly on correctly performed processes of melting and casting, design of a mould and cast element, and a possible heat treatment. The subject-matter of this paper is elaboration of a diagrams and dependencies between parameters of dispersion hardening (temperatures and times of solutioning and ageing treatments) and mechanical properties obtained after heat treatment of the 356.0 (EN AC AlSi7Mg) alloy, enabling full control of dispersion hardening process to programming and obtaining a certain technological quality of the alloy in terms of its mechanical properties after performed heat treatments. Obtained results of the investigations have enabled obtainment of a dependencies depicting effect of parameters of the solutioning and ageing treatments on the mechanical properties (Rm, A5 and KC impact strength) of the investigated alloy. Spatial diagrams elaborated on the basis of these dependencies enable us to determine tendencies of changes of the mechanical properties of the 356.0 alloy in complete analyzed range of temperature and duration of the solutioning and ageing operations.

scholarly journals Surveillance Aesthetics in Latin America: Work in progress

2012 ◽  
Vol 10 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Fernanda Bruno ◽  
Paola Barreto ◽  
Milena Szafir
Keyword(s):  
Latin America ◽  
Los Angeles ◽  
Latin American ◽  
Satellite Images ◽  
Surveillance Culture ◽  
The Usa ◽  
On Line ◽  
And Control ◽  
Selection Of

This on line curatorship presents a selection of 11 works by Latin American artists who incorporate in their creations technologies traditionally linked to surveillance and control processes. By Surveillance Aesthetics we understand a compound of artistic practices, which include the appropriation of dispositifs such as closed circuit video, webcams, satellite images, algorithms and computer vision among others, placing them within new visibility, attention and experience regimes. The term referred to in the title of this exhibition is intended more as a vector of research rather than the determination of a field, as pointed by Arlindo Machado under the term “surveillance culture”. (Machado 1991) In this sense, a Latin America Surveillance Aesthetics exhibition is a way to propose, starting from the works presented here, a myriad of questions. How and to what extent do the destinies of surveillance devices reverberate or are subverted by market, security and media logics in our societies? If, in Europe and in the USA, surveillance is a subject related to the war against terror and border control, what can be said about Latin America? What forces and conflicts are involved? How have artistic practices been creating and acting in relation to these forces and conflicts? Successful panoramas of so called Surveillance Art already take place in Europe and North America for at least three decades, the exhibition “Surveillance”, at the Los Angeles Contemporary Exhibitions being one of the first initiatives in this domain. In Latin America however, art produced in the context of surveillance devices and processes is still seen as an isolated event. Our intention is to assemble a selection of works indicating the existence of a wider base of production, which cannot be considered eventual.The online exhibition can be accessed here.http://www.pec.ufrj.br/surveillanceaestheticslatina/

scholarly journals Influence of the energy electron beam exposure regimes on the structure and mechanical properties of composite coatings

2020 ◽  
pp. 23-27
Author(s):  
T.A. Krylova ◽  
◽  
Y.A. Chumakov ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Electron Beam ◽  
Structural Changes ◽  
Composite Coatings ◽  
Initial State ◽  
Austenitic Structure ◽  
Solid Carbide ◽  
Soft Ferrite

The effect of heat treatment on the structure and properties of composite coatings based on chromium carbide with titanium carbide fabricated by non-vacuum electron beam cladding without has been studied. It was shown that tempering leads to a decrease in microhardness and wear resistance, which is associated with the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The post heat treatment tempering was showed to decrease of microhardness and wear resistance, which leads to the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The bulk quenching of coatings after tempering leads to an increase in microhardness comparable to the values of microhardness in the initial state after electron beam cladding, due to the formation of high hard martensite. The wear resistance of composite coatings after tempering is lower than after cladding due to brittle martensite, which is not able to hold solid carbide particles. The composite coatings obtained at the optimal processing conditions have a combination of improved properties and do not require additional heat treatment, resulting in structural changes, causing a decrease in mechanical properties.

scholarly journals Regression analysis and statistical examination of Knoop Hardness on abrasion resistance in Lyca Beige Marbles

Filomat ◽  
2020 ◽  
Vol 34 (2) ◽  
pp. 609-614
Author(s):  
Burcu Aydin ◽  
Fusun Yalcin ◽  
Ozge Ozer ◽  
Gurhan Yalcin
Keyword(s):  
Mechanical Properties ◽  
Regression Analysis ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Knoop Hardness ◽  
Decomposition Products ◽  
Marble Quarries ◽  
Selection Of

Marbles are secondary decomposition products formed by metamorphism of limestone. Effective classification of marble quarries in terms of quality enables the selection of a sustainable production method and safety application. This evaluation is based on physico-mechanical properties of the samples. Obtained results of physico-mechanical properties of the marbles were statistically analyzed using Stata 14 and SPSS 21 software. The marbles indicated mostly normal physical and mechanical properties. A strong inverse relationship exists between Abrasion Value and Knoop Hardness Determination that indicates a significant nonlinear relationship. Samples were distinguished into 3 groups of close similarity and related properties. The estimated value of the parameters is in the 95 % confidence interval. The equation obtained by regression analysis was used for the determination of resistance to abrasion.

A summary review of mechanical properties prediction methods for textile reinforced polymer composites

2005 ◽  
Vol 219 (2) ◽  
pp. 91-109 ◽  
Author(s):  
J J Crookston ◽  
A C Long ◽  
I A Jones
Keyword(s):  
Mechanical Properties ◽  
Detailed Analysis ◽  
Polymer Composites ◽  
Numerical Models ◽  
Textile Composites ◽  
Prediction Methods ◽  
Reinforced Polymer ◽  
Mechanical Properties Prediction ◽  
The Subject

The use of textile reinforcements for polymer composite components has become a common practice due to the favourable material costs and labour requirements compared with traditional unidirectional prepreg composites, and the high stiffness and strength compared with the use of randomly orientated reinforcements. As a result, determination of both elastic properties and failure behaviour of textile composites has been the subject of substantial research in recent years. This paper presents a review of some of the analytical and numerical models pertaining to the mechanics of textile composites which have been published in the literature. Particular consideration is given to the suitability of models for the analysis of non-orthogonal weave structures such as those which have been deformed in shear during component manufacture. The intention of the paper is not to provide a detailed analysis of the underlying mathematics of the models discussed, but rather to provide an overview of the work conducted in order to direct further reading.

Precipitation Strengthening in AA7449 Aluminium Alloy: Understanding the Relationship between Microstructure, Yield Strength and Strain Hardening

2006 ◽  
Vol 519-521 ◽  
pp. 991-996 ◽  
Author(s):  
G. Fribourg ◽  
Alexis Deschamps ◽  
Yves Bréchet
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Activation Volume ◽  
Rate Sensitivity ◽  
Work Hardening Rate ◽  
Deformation Step ◽  
Evolution Of Microstructure ◽  
Step Heat Treatment ◽  
The Relationship

This paper presents a detailed study of the microstructure and mechanical properties of AA7449 alloy during the two step heat treatment leading to the industrial T7651 temper. It is first shown that reproducing the heat treatment without a deformation step as used in the T7651 industrial temper leads to 2-fold decrease of the precipitation kinetics due to the absence of dislocations, while the resulting mechanical properties (if this change in kinetics is accounted for) are very similar. The work hardening rate is shown to strongly evolve during the heat treatment, and this evolution has been correlated to the evolution of microstructure using a Kocks-Mecking-Estrin analysis. Finally, an analysis in terms of activation volume of the strain rate sensitivity allows for the determination of the dislocation / precipitate interaction in the overaged temper.

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