Acta Technica Jaurinensis

Acta Technica Jaurinensis

Basic info

  • Publisher: Szechenyi Istvan University
  • Country of publisher: hungary
  • Platform/Host/Aggregator: Open journal system ojs
  • Date added to EuroPub: 2019/Sep/29

Subject and more

  • LCC Subject Category: Engineering, Multidisciplinary
  • Publisher's keywords: Engineering, Multidisciplinary
  • Language of fulltext: english
  • Time from submission to publication: 14 weeks

Publication charges

  • Article Processing Charges (APCs): No
  • Submission charges: No
  • Waiver policy for charges? No

Open access & licensing

  • Type of License: CC BY-NC
  • License terms
  • Open Access Statement: Yes
  • Year open access content began: 2008
  • Does the author retain unrestricted copyright? True
  • Does the author retain publishing rights? True

Best practice polices

  • Permanent article identifier: DOI
  • Content digitally archived in: Electronic Periodicals Archive of the National Széchényi Library (Budapest, Hungary)
  • Deposit policy registered in: None

This journal has '91' articles

Comprehensive Survey of PID Controller Design for the Inverted Pendulum

Comprehensive Survey of PID Controller Design for the Inverted Pendulum

Authors: Miklós Kuczmann
Year: 2019, Volume: 12, Number: 1
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Abstract

The survey shows the detailed PID controller design how to stabilize the inclination angle as well as the horizontal movement of an inverted pendulum on a cart system step by step. Pendulum model is based on Euler-Lagrange modeling, and the nonlinear state space model is linearized in the unstable upward position. Controller design is performed by applying the transfer function description. The pendulum has been inserted into a virtual reality laboratory, which is suitable to use in model based control teaching.

Keywords: Inverted pendulum, PID controller design, model based control
The Effect of Filler Orientation and Distribution on the Electrical and Mechanical Properties of Graphene Based Polymer Nanocomposites

The Effect of Filler Orientation and Distribution on the Electrical and Mechanical Properties of Graphene Based Polymer Nanocomposites

Authors: Praveen Rajamani, Róbert Boros
Year: 2018, Volume: 11, Number: 4
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Abstract

The aim of my proposed study is to develop an alternative production technique of graphene via in-situ exfoliation of graphite in the hosting polymer matrix. The production process is carried out by an alternative top-down production technique for graphene-based polymer nanocomposites called ‘pressing and folding’ (P&F), via in situ exfoliation of expanded graphite (EG) inside the hosting linear low-density polyethylene (LLDPE) matrix. In this way, the properties of the samples containing different wt % of EG is studied as a function of P&F cycles, corresponding to EG exfoliation and distribution throughout the matrix volume. The results confirm that the EG particles was exfoliated completely and increasingly distributed in LLDPE with the number of cycles, and mainly oriented on the plane of the samples. This find was confirmed by a low in-plane resistivity was found for samples prepared between 50 and 150 cycles.

Keywords: In-situ exfoliation, Graphene, Polyethylene, Polymer Nanocomposites, Mechanical Properties
Pinpoint Loading Examinations of Poly(lactic acid) Biopolymers

Pinpoint Loading Examinations of Poly(lactic acid) Biopolymers

Authors: Luca Kotrocz, Péter Bakonyi
Year: 2018, Volume: 11, Number: 4
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Abstract

We have made a new mounting unit for Dynamic Mechanical Analysis (DMA) equipment, suitable for measuring microhardness and indentation, and examined its usability on thermoplastic poly(lactic acid) (PLA) material.  We used a Vickers-type microhardness indenter, and examined the dimensions of the indented area and the loading force. This novel unit is suitable for measuring the short and long-term behavior of the material using pinpoint load not only at room temperature (20-23 °C) – like common hardness tests – but at a wide range of temperatures.

Keywords: poly(lactic acid), biopolymer, pinpoint load, Vickers indentation, Dynamic Mechanical Analysis
Halal Meat Supply Chain Traceability based on HACCP, Blockchain and Internet of Things

Halal Meat Supply Chain Traceability based on HACCP, Blockchain and Internet of Things

Authors: Abderahman Rejeb
Year: 2018, Volume: 11, Number: 4
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Abstract

Recently, Halal food has drawn remarkable attention of many consumers around the world. Besides to being unsafe, Halal food such as meat can encounter several issues throughout its supply chain and logistics. At any time, Halal integrity is not guaranteed and risks of becoming non-Halal is the major concern of all parties along the supply chain. To respond to Muslim consumers’ trust concerns in Halal food, many traceability systems were proposed in previous studies based on emerging technologies and  recommended to be incorporated into Halal food supply chains. Nevertheless, all of these systems are centralized, opaque and not enough transparent. To mitigate these problems, blockchain technology is introduced as a ground-breaking innovation with greater decentralization, visibility and transparency. This paper makes a major contribution in suggesting Halal meat supply chain traceability system for real-time food tracing based on embedding Islamic dietary law into HACCP, blockchain and Internet of Things.

Keywords: Halal Meat Supply Chain, HACCP, Blockchain, Internet of Things, Traceability
Methods of Vector Control for Induction Motors

Methods of Vector Control for Induction Motors

Authors: László Varga, Miklós Kuczmann
Year: 2018, Volume: 11, Number: 4
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Abstract

This paper presents the electrical and mathematical models of the three phase asynchronous motors along with the introduction of the field-oriented control model as well as the vector transformations needed for the introduction of the above mentioned terms. The objective of the present paper is to introduce the space vectors and how to build the field-oriented control for a given induction motor drive as well as the transformations and the modell of field oriented control.

Keywords: induction motor, vector control, Field Oriented Control
Defining the Temperature Change of the Brake Disc

Defining the Temperature Change of the Brake Disc

Authors: Melinda Menyhártné Baracskai
Year: 2018, Volume: 11, Number: 3
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Abstract

In the article the thermal analysis of the brake disc and separator disc of a high performance power machine will be presented. As example an agricultural vehicle with weight of 30000 kg and maximum travel speed of 40 km/h will be taken. At stopping the vehicle, the braking system located in the wheel body becomes activated. The traversing of the piston forces the brake discs to friction. Therefore significant amount of heat is generated, which needs to be derived from the system. The article presents the construction of the disc brake system. Providing boundary condition, the radial temperature change of the cooled part of the brake disc will be defined.

Keywords: agricultural vehicle, disc brake, brake oil, braking, temperature
Investigation of Long Cellulose Fibre Reinforced and Injection Moulded Poly(lactic acid) Biocomposites

Investigation of Long Cellulose Fibre Reinforced and Injection Moulded Poly(lactic acid) Biocomposites

Authors: Sándor Hajba, Tamás Tábi
Year: 2018, Volume: 11, Number: 3
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Abstract

We investigated injection moulded composites of a polylactic acid matrix reinforced with cellulose fibers. We produced long fiber reinforced granules (preforms) with the use of two technologies: extrusion coating and film stacking. We examined the effect of fiber reinforcement and manufacturing technology on the properties of the composites. 30 wt% fiber reinforcement caused an increase in both strength and modulus compared to the reference PLA, and we also managed to improve creep resistance.

Keywords: poly(lactic acid), biopolymer, biocomposite, cellulose fiber, injection moulding
Parallel Numerical Creation of Phase-space Diagrams of Nonlinear Systems Using Maple

Parallel Numerical Creation of Phase-space Diagrams of Nonlinear Systems Using Maple

Authors: Flóra Hajdu, Győző Molnárka
Year: 2018, Volume: 11, Number: 3
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Abstract

In this paper the numerical creation of phase-plane diagrams in parallel utilizing Maple is presented. One of the most effective method for studying nonlinear systems is the creation of detailed enough phase-plane diagrams. But in the case of large systems it requires huge amount of numerical calculation, which can be accelerated using parallel computers. Here we show some attempts for this using moderate size known problems. We demonstrate that detailed diagrams can be created fast and efficiently with a SIMD model based algorithm even using simple PC-s. We exhibit that the parallel algorithm taken for one- and two-dimensional problems can be expanded for 3D phase-space diagram creation without any loss of efficiency. In this paper a methodology is showed which can be followed in the study of large dynamical systems as well.

Keywords: parallel computing, SIMD, Maple, numerical analysis, nonlinear system modeling
Uniaxial Tension of a Filament-wound Composite Tube at Low Temperature

Uniaxial Tension of a Filament-wound Composite Tube at Low Temperature

Authors: Gyula Szabó, Károly Váradi
Year: 2018, Volume: 11, Number: 2
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Abstract

The aim of this article is to model mechanical behavior of a filament-wound, rubber-based composite tube subjected to uniaxial tension at low temperature by test experiments and FE simulations. Uniaxial tensile tests at sub-zero temperature (-40 °C) have been carried out on standard test specimens and on hose pieces. furthermore, a uniaxial tensile test has been performed on a hose piece at room temperature as a reference experiment. Reinforcement layers of the composite tube are modeled as transversely isotropic, whereas elastomer liners are described by 2 parameter Mooney-Rivlin hyperelastic material model. Temperature-dependence of elastic constants of composite layers is attributed to the temperature-dependence of rubber, so uniaxial tensile tests on standard test specimens needed to be carried out for determining material properties of rubber at sub-zero temperature (-40°C). Force-displacement results of FE models and experiments of standard test specimen and hose piece show good agreement. Likewise, force-displacement curves of reference experiment (carried out at room temperature) and its related FE simulation are in good agreement with each other. Slope of force-displacement curves of hose piece at -40 °C is nearly 3.4 times the slope of force-displacement curves of hose piece at room temperature.

Keywords: filament-wound composite tube, rubber-based tube, FE model, uniaxial tension, tensile test, material properties at -40 °C, sub-zero temperature
Blockchain Potential in Tilapia Supply Chain in Ghana

Blockchain Potential in Tilapia Supply Chain in Ghana

Authors: Abderahman Rejeb
Year: 2018, Volume: 11, Number: 2
(0 downloads)
Abstract

In a country like Ghana where Tilapia is the most preferred and cheapest source of animal protein, closer attention must be paid to the supply chain of such a product. This paper examines the major issues and problems in Tilapia supply chain and logistics in Ghana, and it suggests the intervention of the new and disruptive technology of blockchain.  Blockchain technology can have the potential to revolutionize the supply chain of Tilapia in Ghana and bring many advantages to the flow of Tilapia from farmers till the end consumers. Besides, it highlights the role of blockchain in ensuring food safety and in rebuilding a trustful network of Tilapia distribution between producers and customers. A model of Tilapia supply chain based on blockchain technology will be exhibited and explained to provide relative solutions to supply chain management processes of Tilapia.

Keywords: Tilapia Supply Chain, Blockchain Technology, Trust, Transparency, Decentralized System
Architectural and Structural Design of Free-form Structures – Case Study

Architectural and Structural Design of Free-form Structures – Case Study

Authors: Kitti Károlyfi, Gabriella László, Ferenc Papp, Raymond Bükkösi
Year: 2018, Volume: 11, Number: 2
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Abstract

This article describes the conceptual design process of an equestrian centre, presenting the covered stadium of the building complex in detail, designed it as a free-form, wide-span steel structure. The main goal of this study is to present the application of the parametric design method through a case study and to examine the interoperability opportunities between architectural and structural design software.

Keywords: free-form, parametric design, wide span, steel structure
Parallel Numerical Creation of 2-parametric Bifurcation Diagram of Nonlinear Oscillators

Parallel Numerical Creation of 2-parametric Bifurcation Diagram of Nonlinear Oscillators

Authors: Flóra Hajdu
Year: 2018, Volume: 11, Number: 2
(0 downloads)
Abstract

This paper presents the numerical creation of 2-parametric bifurcation diagrams of nonlinear oscillators with a simple iterative algorithm, which can be easily parallelized. The parallel algorithm was tested with two simple well-known nonlinear oscillators, the Van der Pol oscillator and the Duffing-Holmes oscillator. It was examined how the resolution (number of iterations) affects the speedup and the efficiency. The test results show that a relative good speed up with a good efficiency could be achieved even using a simple desktop.

Keywords: parallel computing, bifurcation diagram, numerical analysis, nonlinear oscillator, Maple
Thermomechanical Analysis of Vibrations of Silent Block

Thermomechanical Analysis of Vibrations of Silent Block

Authors: Veronika Szüle, Balázs Pere
Year: 2018, Volume: 11, Number: 1
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Abstract

Vehicle components made of rubber or rubber like polymers usually exhibit large deformations.Cyclic deformations may induce increasing in temperature in elastic materials. In this paper after the summary of the basic physical laws and the description of basement of continuummechanics, taking into account the Neo-Hooke material law,an example will be presented which allows to calculate strain-and temperature changes

Keywords: rubber, rubber material laws, high deformations, thermodynamics, Neo-Hooke material law
Determination of Safety Factors for Mango Fruit Paperboard Transport Crates under Refrigerated Conditions

Determination of Safety Factors for Mango Fruit Paperboard Transport Crates under Refrigerated Conditions

Authors: Bernd Sadlowsky, Viktoria Köstner, Margot Mazur, Sina-Kristin Thun, Péter Böröcz
Year: 2018, Volume: 11, Number: 1
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Abstract

The use of corrugated board packaging is very popular in most industry sectors, but the food industry is one of the main consumers. Special requirements are placed on corrugated board in the food industry since the level of humidity necessary may be as high as 85-90% rH and this can greatly influence on the performance of the packaging. This influencing circumstance is taken into account in this paper when estimating a safety factor aimed at reducing risk. Knowing the safety factor can save transport and material costs, and can also prevent serious damage during the distribution of goods. The aim of this study is to determine the influence of humidity, pre-compression and load carriers on the stability of corrugated board mango fruit crates and thus to determine the safety factor. The results show that it is possible to calculate the safety factor by measuring realistic static stresses. Further researches into determining the dynamic stresses are required so as completing the calculation of the safety factor.

Keywords: safety factor, corrugated board, mango fruit crate
Series of Experiments with Thermal Insulation Coatings Consisted of Vacuum-Hollow Nano-Ceramic Microspheres

Series of Experiments with Thermal Insulation Coatings Consisted of Vacuum-Hollow Nano-Ceramic Microspheres

Authors: David Bozsaky
Year: 2018, Volume: 11, Number: 1
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Abstract

Because of the rigorous regulations in the 21st century it has become a serious task for designers to find more effective ways for thermal insulation. One of these options is the application of nanotechnology-based materials. Among nano-scale structured materials the most uncertainties are found about the thermal insulating quality of thermal insulation coatings consisted of vacuum-hollow nano-ceramic microspheres. Complete agreement had not been already found about the mechanism of their insulating effect. In order to explore and describe the thermodynamic process inside nano-ceramic coatings (NCC) 6 series of heat transfer resistance experiments were performed in 2014-2017. Several building structure configurations with 12 different orders of layers were tested with a standard heat flow meter. On basis of these results it could be concluded that in case of nano-structured materials convective heat transfer coefficient might be taken account in different way than in case of traditional macro-structured thermal insulation materials.

Keywords: nanotechnology, thermal insulation coating, nano-ceramic

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