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Probrano po
3.632 (51-60)
NaslovCompetencies of production in SMEs in assembly industries in a digital, volatile business environment / Maria Hulla, Christian Ramsauer.
Materijalni opisGraf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisSMEs are currently confronted with major challenges such as increasing uncertainty and volatility. In order to face these challenges, agility and digitalization can be implemented. Both concepts bring about numerous opportunities and new competency requirements. Currently, there are few scientifically based, practical training courses that focus on digitization and/or agility. The aim of this paper is to provide a roadmap for the development of the training concept. In this training, participants will be able to acquire theoretical content on a learning platform in a flexible way and they will be able to apply this knowledge in a learning factory. Based on a literature overview, requirements for such a training and the necessary skills in a digital, volatile business environment will be given.
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51
NaslovStudy on deformation behavior of non-hardenable austenitic stainless steel (grade X5CrNi18-10) by hot torsion tests / Imre Kiss, Vasile Alexa.
Materijalni opisIlustr., graf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisThe steel's deformation resistance, in which high strain rates have an important influence on the mechanism of failure, might be obtained from a suitably instrumented torsion test. Determination of stainless steel deformability by hot torsion test is the only method that allows obtaining large deformations along the length of the test specimen, so it is mainly used to determine the characteristics at large plastic deformations. By this method, the hot deformability of stainless steel is determined by subjecting to hot torsion the cylindrical stainless steel specimens maintained at the deformation temperature in a tubular oven belonging to the Laboratory of Metal Rolling and Plastic Deformation, at the Faculty of Engineering – Hunedoara, University Politehnica Timişoara. For the experimental hot torsion tests, several stainless steel grades were used and included in a large series of studies destined to determining the deformation behavior of steel. Having in view the previous results obtained in the study of deformability characteristics of two stainless steels (hardenable martensitic stainless steel, grade X46Cr13 and non–hardenable ferritic stainless steel, grade X6Cr17), this paper includes the results of the hot torsion tests conducted to find the deformation behavior of the non–hardenable austenitic stainless steel (grade X5CrNi18–10). For analysis of laboratory hot torsion tests results the univariate and multivariate regression analysis was used, estimating the relationships among the hot–testing temperature, torque moment and number of torsions up to the breaking point of the specimens of austenitic stainless steel. Therefore, the optimum range of heating temperatures applied for deforming the studied steels results clearly from the deformability – temperature (plasticity – temperature and deformation resistance – temperature) diagrams.
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52
NaslovThermal and acoustic insulating gypsum composite material with improved water resistance / Volodimir Yakovich Kersh, Andriy Valeriyovich Kolesnikov, Mikola Volodymyrovich Hlitsov, Sergіi Ivanovich Gedulyan.
Materijalni opisGraf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisThe article discusses methods for obtaining building heat and sound insulating composite material based on gypsum with high resistance to water. An additional characteristic is considered - the water resistance index, in which the role of material strength in the wet state is enhanced. The proposed characteristic is used to optimize the heat and sound insulating composition based on gypsum. The material contains matrix gypsum-cement-ash binder and a mixture of aggregates. The result of the planned experiment shows that the water resistance index more adequately reflects the strength of the composite in the wet state compared to the softening coefficient. An optimization of the complex properties of the composite is given in accordance with its intended purpose. As a result of the study, an optimal waterproof composition with improved thermal insulation and sound insulation characteristics was obtained.
rrep
53
NaslovPrediction of effective elasticity coefficients of composite biofuel / Vasyl Klymenko, Volodymyr Kravchenko, Vasyl Gutsul, Viktoriya Kravchenko, Viacheslav Bratishko.
Materijalni opisIlustr., graf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisIt is suggested that fuel pellets made of composites based on solid plant waste should be considered as stochastic systems that are anisotropic in microvolumes but isotropic in the entire structure, i.e. quasi-isotropic in volume. Based on this hypothesis and the analysis of the known micromechanical models for forecasting physical and mechanical constants of composite materials, the expediency of using the Reuss-Voigt and Hashin-Strickman models to determine the effective elastic coefficients of composite biofuels is substantiated. The results of calculations made on these models for a number of two-component biofuel pellets are given. An experimental evaluation of effective Young's modulus and Poisson's ratio for two-component pellets with "straw + brown coal" composition was carried out. The obtained results of experimentally determined values of coefficients satisfactorily correspond to their calculated values: deviations are up to 26%. The Reuss-Voigt model was used in the calculations because the conditions required for the application of the Hashin-Strickman model are not met for composite pellets consisting of straw and brown coal. The results of the study will be useful in calculating or selecting press equipment for the production of quality fuel pellets from composites based on solid plant waste.
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54
NaslovInfrared printing technique for the security marking of traceability certificates for meat products / Dražen Crčić, Jana Žiljak Gršić, Denis Jurečić.
Materijalni opisIlustr.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisThe focus of this paper is the introduction of new security elements into the authenticity of information on documents which concern the traceability of products. This article proposes dual marking using the infrared printing technology, which involves differences between the visible and infrared spectrum and separate detection of certain information with an infrared camera. Each meat product is assigned a unique designation, embedded in the document and hidden from the naked eye, in order to prevent changing, scanning or modifying with currently known techniques. A product receives a certificate with a security approval which carries information about the complete traceability of the product. A new central data registry which collects information from all necessary sources is proposed. The web portal and the accompanying database are designed to work in the cloud. The security of the exchange of data between the server and the user is ensured. The information about the traceability and the delineation between the visible and infrared hidden are approved and coordinated by the relevant authorities, breeders, distributors and sellers. The design of the entire information presents completely transparent information about the products to the end consumer.
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55
NaslovA novel coplanar waveguide-fed compact microstrip antenna for future 5G applications / Mustafa Berkan Bicer.
Materijalni opisIlustr.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisIn this study, a coplanar waveguide-fed compact microstrip antenna design for applications operating at higher 5G bands was proposed. The antenna with the compact size of 8 x 12.2 mm2 on FR4 substrate, having the dielectric constant of 4.3 and the height of 1.55 mm, was considered. The dimensions of the radiating patch and ground plane were optimized with the use of artificial cooperative search (ACS) algorithm to provide the desired return loss performance of the designed antenna. The performance analysis was done by using full-wave electromagnetic package programs based on the method of moment (MoM) and the finite integration technique (FIT). The 10 dB bandwidth for return loss results obtained with the use of the computation methods show that the proposed antenna performs well for 5G applications operating in the 24.25 – 27.50 GHz, 26.50 – 29.50 GHz, 27.50 – 28.35 GHz and 37 – 40 GHz frequency bands.
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56
NaslovOptimization of managerial, organizational and technological solutions of grain storages construction and reconstruction / Aleksandr Meneylyuk, Aleksey Nikiforov.
Materijalni opisGraf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisThe work is devoted to the important problem of optimization of managerial, organizational and technological solutions of construction and reconstruction of separate grain storages and the management of specialized building enterprise as a whole. Models of the company for the grain storages construction and renovation were designed, analyzed and described: multidimensional organizational structure, computer model of the enterprise. The results of a two-stage construction products cost optimization were presented. The recommendations for the adoption of optimal organizational and technological solutions were developed. The method for justification of financial income level for the grain storages construction and reconstruction using project management principles and provisions of the existing regulations was proposed.
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57
NaslovNumerical and experimental study of the impeller of a liquid pump of a truck cooling system and the development of a new open-type impeller / Rishat Salakhov, Andrey Ermakov, Elvira Gabdulkhakova.
Materijalni opisIlustr.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisTypically, closed-type impellers are more efficient than open-type impellers, but in the manufacture of closed-type impellers, cost of wheels is higher. This paper describes the development of cost-effective and simple impeller wheel for a fluid pump in the truck cooling system. To perform this task, the numerical computations of a standard impeller wheel were carried out, its characteristics were also obtained from a test bench, the standard impeller wheel model was verified. The open-type impeller wheel was developed according to the current dimensions of standard impeller wheel and then analyzed with the numerical computations by the software ANSYS CFX (Academic license) computational fluid dynamics. The developed open-type impeller wheel works very effectively in spite of performance degradation by 5% in comparison to the closed-type impeller wheel. When working as a part of engine, the pump efficiency is 0.552-0.579. The maximum value of the pump efficiency is 0.579, it can be achieved at the highest speed of the pump (4,548 rpm and 655 l/min).
rrep
58
NaslovDesigning a sustainable world class manufacturing model in the automotive industry in Iran / Zahra Pourvaziry, Gholamreza Hashemzadeh Khorasgani, Mahmud Modiri, Hassan Farsijani.
Materijalni opisGraf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisThis study is functional in terms of purpose and descriptive-exploratory in terms of doing research. The method of data collection is library and field studies using a questionnaire tool. Those with relevant postgraduate qualifications and at least ten years of working experience, especially management experience in the automotive industry with a sufficiently motivated executive background to participate were chosen. In the quantitative section, the experts include nine executives and senior experts in the automotive industry who were selected through snowballing. The most important dimensions and criteria of a sustainable world class manufacturing model are identified by a theoretical literature review and interviews with the experts, and they were then screened and localized with expert opinions and fuzzy Delphi techniques. After collecting data through a paired comparisons questionnaire, the data were analyzed by using a fuzzy-dimensional network analysis process hybrid technique. The findings of fuzzy DEMATEL indicated that the dimensions of "environmental", "economic" and "social" sustainability help in achieving sustainable world class manufacturing.
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59
NaslovPlacement and quantitating of FACTS devices in a power system including the wind unit to enhance system parameters / Amir Bagheran Sharbaf, Ali Asghar Shojaei.
Materijalni opisGraf. prikazi.
Način izrade datotekeizvorno digitalna građa
Vrstačlanak
OpisOne of the main concerns of network operators is the enhancement of system parameters; accordingly, a set of different means to this end are posed. However, the use of renewable energies such as the wind could increase the importance of the debate over sustainability and conditions of power system parameters. In this study, the condition of said parameters is examined by placing FACTS (Flexible Alternating Current Transmission System) devices in a 24-bus power system including a wind farm. Research data entailing information on the wind and the amount of consumption load per year are classified by using the K-means classification algorithm; then, the objective function is obtained according to the parameters intended for optimization. This function is optimized by using the Honey-bee mating optimization (HBMO) algorithm followed by obtaining the suitable place and amount for FACTS devices. The results showed that the examined parameters are optimized when using FACTS devices.
rrep
60
3.632 (51-60)