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Abstract

Our research team has developed a system and methodology for measuring psycho-physiological parameters, which can be used to determine the level of fatigue and fitness of the person being measured. This article describes the electroencephalography (EEG) part of this system. This article covers the technical and mathematical background of EEG measurement, the selection and implementation of the measurement tool in the development environment, and the development of the measurement and processing algorithm. The result is a system that can detect, digitize, and process the digitized signal from the brain, and save the processed signal in an XML database.

Open access

Abstract

Plukenetia conophora (Nigerian Walnut) leaf extract was studied as a corrosion inhibitor on Al–Zn–Cu alloy in acidic (HCl and H2SO4) media using gravimetric, gasometric and electropotential techniques. The study showed that the inhibition efficiency (IE) increased as the concentration of the leaf extract increased and reached the peak (94.8%) at 0.8 g/L in 1 M HCl. In the two acidic media, P. conophora leaf extract exhibited good corrosion inhibition properties on the Al–Zn–Cu alloy samples due to adhesion of the extracts on the samples' surfaces. The adsorption process of the extract on the alloy sample surfaces was found to be spontaneous and perfectly obeyed the Langmuir isotherm model. Thus, P. conophora leaf extract is recommended for utilisation as a potential replacement for toxic inorganic inhibitors and for application in paint and coating industries.

Open access
International Review of Applied Sciences and Engineering
Authors: Olena Yakymchuk, Dmytro Yakymchuk, Nataliia Bilei-Ruban, Iryna Nosova, Serhiy Horiashchenko, Kostyantyn Horiashchenko, Tetyana Kisil and Viacheslav Tuz

Abstract

The objective of this research is to develop the equipment for liquid-jet forming of women's headwear hats, which will allow expanding design assortment of these products. The equipment for cyclic liquid-jet forming of headwear hats in liquid-active working environment (LAWE) with forming element rotation was designed. The mechanism of movement and orientation of liquid -jet forming nozzle was developed, which allows influencing fabric parts by flooded and controlled liquid-jet, repeating the contour at a certain distance and with appropriate angle attack on each technological section of the part. The conducted experimental research allowed to receive semi-spherical forms of headwear hats from six fabrics suit-coat assortments, which are one of the most difficult forms of non-seam forming. Completely formed hats of a given complex configuration were obtained by liquid-jet forming, different from standard semi-spherical ones. The developed equipment provides mobility of the production from the point of view of quick equipment adaptation due to action use of flooded controlled liquid-jet and forming of a significant number of various hats contours, various combinations of technological forming modes.

Open access

Abstract

Recently, the thermal performance of the parabolic trough collector (PTC), augmented to be more applicable and efficient, received intensive research. These studies aimed to improve heat transfer in the receiver part, in order to decrease the heat loss, and enhance the heat transfer to the thermal fluid. Many previous review papers focused on the numerical sides rather than the experimental side. Several research papers recommended doing more research in the experimental field; in order to decrease the gap between the numerical and experimental results, as well as increase the confidence level of what has been done in the theoretical field researches. Regarding the recommendations of the recent papers to decrease the gap between numerical and experimental aspects, this review paper focused on the recent experimental research related to thermal enhancement performance in the receiver part of the parabolic solar collector. In this research, different categories of the enhancement methods are discussed in detail through this review, namely nanofluids, surface modifications, and inserts models or the two categories combined together. We discussed these categories for different parabolic troughs considering only the recent experimental research between the period from 2014 up to 2019. Some parameters were discussed, such as the main dimensions of the examined receiver and parabolic collector. Moreover, types of nanoparticle specifications and preparation methods with different base fluids were highlighted. In addition, we discussed different aspects of using inserts models and inlet and outlet surface modification methods. Finally, the main thermal efficiency and thermal performance enhancement results for each work were presented.

Open access

Abstract

The control of higher order linear system is one of the main fields of research area that has been studied for decades because of the difficulty in designing a controller for such systems. One of the best approaches to solve this problem is by reducing the order of the system into a second orders, based on this reduction many approaches can be proposed for controlling the higher order system, therefore many reduction methods are suggested and developed for this purpose, one of these methods is the Mixed Reduction Method (MRM). The first contribution of this paper is to improve the efficiency of MRM by using a flower optimization algorithm.

The second contribution of this paper lies in proposing a hybrid Neuro-Robust deadbeat controller using Matlab facilities to control higher order linear systems based on the optimized MRM. Where the robust deadbeat control algorithm is combined with a modified adaptive radial basis neural network to improve the robustness and efficacy of the deadbeat controller, which is partially lost when designing this controller for the higher order based on model reduction. The suggested radial basis function neural network has a simple design. The proposed control scheme assures the stability of the overall closed loop-controlled system; therefore, it can be applied to control any linear higher order systems. Results of different simulation examples show the efficiency of the proposed hybrid controller (Neuro-robust deadbeat) in tracking different reference signals compared to the robust deadbeat controller.

Open access

Abstract

The availability of freshwater is increasingly becoming an international concern because of the increase in population and the diminishing forest area as a source of water, leading to a freshwater crisis. The coastal and swamp areas abound in water, but humans cannot consume it due to the quality. One effort that can be done in overcoming this problem is by treating existing raw water with solar distillation methods. However, the main obstacle faced in this method is the intensity of sunlight that is not stable throughout the day so that the productivity of distilled water is disrupted. Using the appropriate phase change material (PCM) is expected to make the distillation process smoother and increase the production of pure water. In this study, myristic acid was used as PCM in double slope solar distillation system. Through observation, it was obtained that the average water temperature in the basin equaled to 42.5 °C while the melting point of the myristic acid was 58 °C. This shows that the use of myristic acid as an energy storage through phase change process does not occur. Therefore, the use of myristic acid as PCM for increasing the productivity of solar distillation in these experiments is not effective because the melting point of PCM is higher than water temperature in the basin. Therefore, material with a phase change temperature below 42.5 °C is more appropriate to use in these conditions.

Open access

Abstract

Virtual machine (VM) management is a fundamental challenge in the cloud datacenter, as it requires not only scheduling and placement, but also optimization of the method to maintain the energy cost and service quality. This paper reviews the different areas of literature that deal with the resource utilization prediction, VM migration, VM placement and the selection of physical machines (PMs) for hosting the VMs. The main features of VM management policies were also examined using a comparative analysis of the current policies. Many research works include Machine Learning (ML) for detecting the PM overloading, the selection of VMs from over-utilized PM and VM placement as the main activities. This article aims to identify and classify research done in the area of scheduling and placement of VMs using the ML with resource utilization history. Energy efficiency, VM migration counts and Service quality were the key performance parameters that were used to assess the performance of the cloud datacenter.

Open access

Abstract

Due to recent changes in the labour market, recruitment and retaining employees have become more important than ever. Research dealing with the appearance of new generations in the labour market has found that they are less loyal to their employers, have high demands, and the key factors that they consider when choosing a job are salary, career opportunities, working environment, and work-life balance. As numerous studies in recent years have proved the importance of a healthy lifestyle in the context of labour, the question has arisen whether opportunities for sport participation and services supporting the well-being of employees have an influence on young people when they are seeking employment. We carried out an online survey to find out what students of the University of Debrecen think about the issue. The results were in line with the findings of previous studies, that is, young people look for high salaries, good working conditions, work-life balance and career opportunities when choosing a job. However, respondents did not identify sports opportunities and well-being benefits as major factors Yet, we found significant differences between different groups in terms of preference of particular factors, depending on sex, marital status, and whether someone does physical exercises regularly, and whether someone works while attending a university course or not.

Open access
International Review of Applied Sciences and Engineering
Authors: Adebayo Surajudeen Adekunle, Adekunle Akanni Adeleke, Peter Pelumi Ikubanni, Peter Olorunleke Omoniyi, Tajudeen Adelani Gbadamosi and Jamiu Kolawole Odusote

Abstract

Heat treatment industries require various quenching media to improve the properties of the materials to be quenched. Petroleum based mineral (PBM) oil, a non-biodegradable oil, is popular amongst others quenchants in heat treatment processes. Recently, biodegradable oils mostly in their raw, unblended and unbleached forms have been employed for quenching of various engineering materials. Therefore, the present study examined the effects of some selected bio-quenchants in blended raw (BR) and blended bleached (BB) forms on the mechanical properties and microstructure of solution heat treated aluminum (Al)-alloy. Edible vegetable oil (70% by volume) was blended with 30% by volume of jatropha oil to form the bio-quenchant oils. Another set of bio-quenchants were formed by bleaching the raw oils before mixing so as to reduce the oxidation level and contaminations in the oil. The Al-alloy is solution heat treated at 500 °C and soaked for 15 min in an electric muffle furnace before quenching in the various established bio-quenchants. Results showed that samples treated in blended raw melon (BRM) oil have higher tensile strength of 151.76 N/mm2 while samples quenched in blended bleached melon (BBM) oil have higher hardness value of 61.00 HRC. In accordance to the results obtained the bio-quenchants were found to be effective replacement to the PBM oil.

Open access

Abstract

The article highlights the worldwide dissemination of precision agriculture scientific researches published from the period of 1996–2018, data gathered in the Scopus citation database, using the science mapping method. The findings show that there is a constant rise in the number of publications in precision agriculture. The USA is not only leading in the adoption of precision agriculture technologies but also in the publication of papers, accompanied by China placed in second place. The most frequent keywords highlighted the main topics authors concentrated on more, and the national affiliation of most cited papers was the USA. The main prominence and contributions of the results present scientific research trends in precision agriculture in the last two decades, and demonstrate the main countries, authors and organizations who have contributed, and were more productive in this area.

Open access

Abstract

The main idea of the current paper consists in introducing the fractional order calculus in a control system. To control the system, an adaptive control technique with reference model is used. The fractional order models for the plant and reference model are obtained. To achieve the performances imposed by the fractional order reference model, a fractional order adaptive control law is proposed, which is a combination of two methods (MIT and Lyapunov stability). The original contribution in this paper is the use of fractional order calculus in the combined MIT and Lyapunov stability method and showing the dynamic behavior of the system. Several simulations are used to emphasize the effectiveness and benefits of the proposed method.

Open access

Scope of the study was to find more effective N fertilisation doses and applications to reach not only higher quantity but better quality grains as well as to be able to help preserving the continuity of feed and food quality improvement, since wheat is one of the most consumed crops all over the world.

Samples of winter wheat (Triticum aestivum L.) varieties harvested from the experimental field of the Szent István University in two consecutive crop seasons had been examined in the laboratory of the Crop Production Institute. Effects of nitrogen (N) application on the performance of grain protein were tested. Five high quality winter wheat varieties were studied regarding grain quality traits affected by applying undivided and split doses of N. The evaluated samples show that increasing doses of N topdressing and increasing time of application have beneficial effects on the yield and the value of protein content. Wheat grain protein value ranged between 9.9% of the untreated Mv Karéj and Alföld, where the 120+40 kg ha-1 N was applied resulting in the highest value of 16.0%. Similarly, the gluten values among untreated and N applied plots were in a wide range. Mv Karéj had the lowest wheat gluten value on untreated plot with 18.4% and Alfold had the highest value with 36.8% on the plot where the 120+40 kg ha-1 N was applied. There were no significant changes recorded on test weight and thousand kernel weight. In the case of baking quality, there were significant differences between varieties. The best records were obtained in the case of Mv Toborzö followed by Mv Karéj.

Open access

Medium chain fatty acids are candidates of partial sulphur dioxide replacement in wine, as a solution to the growing consumer concerns about chemical additives. In botrytised sweet wine specialties, large amount of sulphur dioxide addition is one of the effective practices to stop alcoholic fermentation. Increasing medium chain fatty acid levels up to 80 mg l-1 was tested as a sole inhibitor on solid agar surface. S. bacillaris seemed to be the most sensitive, S. cerevsisiae and S. bayanus were more tolerant, while Z. bailii showed the highest tolerance. Then, increasing medium chain fatty acid levels up to 40 mg l-1 combined with 100 mg l-1 sulphur dioxide was introduced into a Tokaj Essence under refermentation. After 56 days, the highest dosage had pronounced effect on the yeast population, but the refermentation was not inhibited completely. Medium chain fatty acids have varying inhibitory effect on botrytised wine-related yeasts, moreover, it could be used effectively in media with high ethanol content, unlike Tokaj Essence.

Open access
Acta Alimentaria
Authors: J.A. Pino, E. Sauri-Duch, O. Sosa-Moguel, C.A. Can-Cauich, V.M. Moo-Huchin and L. Cuevas-Glory

An aroma distillate with the odour note described as ‘fresh Habanero chilli pepper' was obtained from hydrodistillation of the fruit. GC-MS analysis of the volatile constituents from the aroma distillate allowed the identification of 100 compounds, most of them esters followed by aldehydes, alcohols, terpenes, ketones, and acids. Encapsulation process of the aroma distillate by spray drying was optimised using response surface methodology. Independent variables were inlet air temperature (150-200 °C) and carrier (maltodextrin 10 DE and gum arabic in 2:1 ratio) content (10-20% wb), while response variables were powder moisture and volatiles retention. Moisture content of the powder varied inversely proportional to the air temperature, while the volatile retention was directly related. Retention of volatiles in the powder increased when the carrier content increased, while this factor negatively affected moisture content. Based on the optimisation model of the response variables, the powder with the highest flavour quality was obtained with an air inlet temperature of 200 °C and 20% wb carrier content, with 4% moisture content and 88.6% volatiles retention.

Open access

The aim of the study was the identification and characterisation of coagulase-positive Staphylococcus bacteria obtained from food matrices by mass spectrometry and molecular methods. A total of 46 coagulase-positive Staphylococcus isolates were collected from different foodstuffs. The Staphylococcus isolates were identified by MALDI-TOF MS and confirmed by the presence and sequence analysis of the Staphylococcus protein A gene. Staphylococcal enterotoxin genes were also investigated by multiplex PCR. Based on the identification of strains by the MALDI-TOF MS technique and spa-typing, all strains were identified as Staphylococcus aureus. Based on their MS peak profiles, the isolates matched the spectra of three S. aureus reference strains in the Bruker MALDI Biotyper database, with identification scores higher than 1.999 in the case of all 46 (100%) isolates. The isolates showed great genetic variability. Twenty spa types were identified, from which most lineages are capable of colonizing humans. Fifty percent of the strains harboured at least one of four enterotoxin genes (seg, seh, sei, and ser), but none of the classical enterotoxin genes could be detected.

Open access

The surplus of waste glycerol, by-product of the biodiesel production process, is available at the global market. Some species of the genera Streptomyces have the ability to assimilate glycerol and convert it into valuable metabolic products. In the present study, the ability of Streptomyces hygroscopicus to assimilate waste glycerol and convert it into metabolic compounds with antifungal activity against four phytopathogenic fungi obtained from apple fruit samples expressing rot symptoms, was investigated. Production of antifungal metabolites by S. hygroscopicus was carried out in 3 l stirred tank bioreactor through 7 days. Fermentation was carried out at 27 °C with aeration rate of 1.5 vvm and agitation rate of 100 r.p.m. The aim of this work was to analyse bioprocess parameters and to determine at which stage of bioprocess the production of antifungal metabolites occurs. Activity of the cultivation liquid on two isolates of Alternaria alternata and two isolates of Fusarium avenaceum were determined every 12 h using in vitro well diffusion method. It was found that the maximum production of antifungal metabolites occurred at 108 hour of cultivation. Formed inhibition zones have shown that the produced antifungal metabolites have high efficacy on tested phytopathogenic fungi (inhibition zone diameter higher than 35 mm for all test organisms).

Open access

Due to the shift in consumer behaviour, the proportion of well informed, conscious consumers has been growing steadily, and functional foods with their capacity to protect health have been gaining more and more ground. To achieve market success in the field of functional foods, producers should be able to communicate information effectively concerning health issues and their newly developed product should indeed meet consumer expectations. The aim of our study was to identify and define the components of the dimensions of consumer attitudes in Hungary together with the barriers and motivators of health behaviour. Our research also examined how these factors influence consumer willingness to consume functional foods. Our surveys were carried out in focus groups of health-conscious (n=8) and not health-conscious (n=8) consumers. Our findings confirmed the adequacy of the international dual model, regarding the attitudes of Hungarian consumers towards functional food. Moreover, we also explored the most popular health food categories and sources of information on nutrition.

Open access

Abstract:

First Hungarian Active House refurbishment won the Active House Award and the Energy Globe Hungary prize in 2017. This paper provides insight into the renewal design process of the typical home from the 70’s under disadvantageous site conditions. Dynamic thermal simulations helped to gain insight into space organization and building envelope concepts and their effects on comfort and energy performance. The Active House Standard was applied to evaluate the calculation results. The most advantageous concept was selected for final design elaboration and construction. The implemented building proved that in the refurbishment process it is possible to achieve highest level of efficiency in operation energy consumption with positive yearly balance by simultaneously being able to rearrange the complete interior space and as a consequence the building shape and envelope into a competitive design at international level.

Open access

Abstract:

During sketch design stage for the new block of the University of Pécs, Medical School comfort and lighting simulations were applied to quantify optimization strategies. Simulation cases about shading possibilities, façade glazing ratios and internal heat storage masses evaluate the impact of illumination, solar gains, loads and heat transmission on visual and thermal comfort. The goal was to select the most favorable comfort, coupled with maximum reduction of investment costs. Concepts represent 14% (shading), 10% (reduced wall-window ratio), 11% (slabs without suspended ceilings), and 17% (combined wall-window ratio and thermal mass) improvement in thermal comfort performance, and it was proposed for further design.

Open access

Abstract:

The aim of the research is to make a comparison between system integrated measurement technologies in the field of engineering education in order to the students getting more detailed knowledge about the high level problem solving. A comparative case study was conducted with 3 different types of systems, as follows: Beckhoff, National Instruments, and HBM. The criteria of the systems are determined based on experience and the importance level of them was calculated by preference matrix. The ranks of the alternatives are calculated by Kesselring method, which provides the effectiveness value of the systems compared to the benchmark. The result of the paper shows a suitable method for selecting engineering systems.

Open access

Abstract

Regional flood frequency analysis is considered to be an important and popular method for estimating different hydrological variables at ungauged sites. The estimation of the index flood is the essential problem when this method is applied. The objective of the study is a comparison of the estimation of the mean annual flood (or index flood) by using two approaches based on the ‘so-called’ index flood method and top-kriging. The concept behind these methods permits estimating the mean annual flood at ungauged locations using information taken from gauged sites located within the same homogeneous pooling groups. The study area comprises 104 gauging stations on the whole territory of Slovakia. The observation period of the annual maximum discharges of the selected stations was from 1961-2010. The identification of the homogeneous pooling group was performed using a non-hierarchical k-means clustering algorithm. The optimal number of clusters is determined by the Silhouette method. As a result, eight homogeneous pooling group clusters were identified. Finally, the results of the estimated mean annual floods using the index flood method and top-kriging were compared with the observed data. Top-kriging provided better results than the classical index flood method for estimating the mean annual flood at ungauged sites.

Free access

Abstract:

This paper presents a design procedure of a switched-mode power converter, the well-known synchronous buck converter: the calculating method, and how to choose the parts of the converter are presented in detail, like the inductor, the capacitor and the semiconductors as well as the design of the state feedback. During the design process the efficiency and the high switching frequency are very important: the switching semiconductors are Gallium Nitride based. Then, a linear-quadratic regulator is designed and applied to the particular case of a buck converter.

Open access

Abstract:

Numerous volume rendering techniques are available to display 3D datasets on desktop computers and virtual reality devices. Recently the spreading of mobile and standalone virtual reality headsets has brought the need for volume visualization on these platforms too. However, the volume rendering techniques that show good performance in desktop environment underachieve on these devices, due to the special hardware conditions and visualization requirements. To speed up the volumetric rendering to an accessible level a hybrid technique is introduced, a mix of the ray casting and 3D texture mapping methods. This technique increases 2-4 times the frame rate of displaying volumetric data on mobile and standalone virtual reality headsets as compared to the original methods. The new technique was created primarily to display medical images but it is not limited only to this type of volumetric data.

Open access

Abstract:

A building physics supported development was undertaken for the new block of the University of Pécs, Medical School. During sketch design stage climate, lighting and energy simulations were applied to quantify energy optimization strategies. Simulation cases assess the impact of shading technologies, wall-window ratios and thermal masses on used thermal energy demand. Based on a previous study about visual and comfort performance, goal was to identify the highest energy efficiency rates with maximum investment cost savings. Besides best comfort results, the most optimal development represents 9% saving in used thermal energy, and they were proposed for further design.

Open access

Abstract:

Development of thermal efficiency of the concentrated solar energy especially parabolic trough collector using various nanofluids types has a taken high interest in recent years. In this article enhancement thermal performance inside the heating collecting element of trough collector type LS-2 was simulated and improved using nanofluid consist of Tungsten Oxide WO3 inserting in Syltherm 800. Nanofluid effect was examined by solving the energy balance equation using MATLAB Software to cover wide range concentration volume 1-5% and inlet temperatures ranging from 350-650 K for the turbulent flow. The heat transfer performance and thermal efficiency were improved based on the results, and a notable increase was obtained when volume concentration had been increased compared with base fluid.

Open access

Abstract:

This paper describes the adaptation of the formex configuration processing to the computer program Grasshopper 3D and focuses on the applied mathematical solutions. Formex algebra is a mathematical system, primarily used for planning structural systems like truss-grid domes and vaults, together with the programming language Formian. The goal of the research is to allow architects to plan truss-grid structures easily with parametric design tools based on the versatile formex algebra mathematical system. To produce regular structures, coordinate system transformations are used. Owing to the abilities of the parametric design software, it is possible to apply further modifications on the structures and gain special forms. The paper covers the basic dome types, and it introduces additional dome-based structures using special coordinate-system solutions based on a spherical coordinate system, vault structures and their modifications based on a cylindrical coordinate system and circular structures and their modifications based on polar coordinates. Moreover two rotational grid tools are introduced, which uses coordinate system transformations on a unique way to create surfaces of revolutions based on the given generating curve and create grid structures on these surfaces. It also describes the solution technique to implement the triangular grid version of every one of these tools based on diamatic domes. The adaptation of formex algebra and the parametric workflow of Grasshopper together give the possibility of quick and easy design and optimization of special truss-grid domes.

Open access
Pollack Periodica
Authors: Dávid Nagy, Tamás Mihálydeák and László Aszalós

Abstract:

Correlation clustering is a widely used technique in data mining. The clusters contain objects, which are typically similar to one another and different from objects from other groups. In the authors previous works the possible usage of correlation in rough set theory were investigated. In rough set theory, two objects are treated as indiscernible if all of their attribute values are the same. A base set contains those objects that are indiscernible from one another. The partition, gained from the correlation clustering, can be understood as the system of base sets, as the clusters contain the typically similar objects (not just to a distinguished member) and it considers the real similarity among the objects. In this work the extension of this study is presented, using the method to approximate graphs representing similarity relations.

Open access
Pollack Periodica
Authors: László Pusztai, Balázs Kocsi, István Budai and Lajos Nagy

Abstract:

A key role of production managers at manufacturing companies is to make economy-based decisions related to production scheduling. If the production is subject to uncertain factors, like human resource or lack of standardization, production planning becomes difficult and calls for advanced models that are tailored to the manufacturing process. This research investigates a real furniture manufacturing system from both managerial and materialflow points of view. Statistical simulation was run on the manufacturing process, where the possible production structures were given. ANOVA analysis was calculated in order to identify those activities that have the most significant influence on the profit.

Open access

Abstract:

This paper deals with the dynamical analysis of a crane model. Truss finite elements are used to discretize the suspending chains with the so called updated Lagrangian description. This nonlinear model is regarded to be the best approximation to which linear models are compared. The inertia and independent degrees of freedom are also taken into consideration by linear models. The goal is to find a linear model, which can be used as an observer in antisway control of a crane.

Open access

Abstract:

Modeling and robotic handling of a plastic box buckle is discussed in this paper. The closing mechanism of the box buckle is simulated to determine the characteristic of the nonlinear load-deflection curve. An intelligent end-effector was designed and manufactured to handle the assembly with a robot. The closing force is measured by a built-in load cell and its values are processed by a micro-controller. The intelligent end-effector can be used in a robotic system, which deals with different snap-fit applications.

Open access

Abstract:

In 2013 Typhoon Haiyan, devastated several portions of the Philippines, which resulted in more than 7,000 deaths and thousands made homeless. The aim of this study is to propose a design of a permanent shelter as a continuation of the I-Siguro Daan Transitional Shelter, which was successfully deployed in 2014 and produce a transitional shelter prototype, for the victims of typhoon Haiyan. In order to develop the methodological design of the Permanent Shelter, the author presented several factors into consideration: the understanding how the rural communities use the present I-Siguro Daan Transitional Shelter; to further develop and improve the interior space of the shelter; to propose a better roof design; and to design a sustainable toilet and kitchen area for the users. Methodologies used in the study were the use of surveys and interactions with the community, which focuses on gaining the understanding how the communities use the present I-Siguro Daan Transitional Shelter. By exploring related case studies and literatures, site surveys and consultations with different groups, the resulting Permanent Shelter will a promising solution for improving the lives of the communities while also providing groundwork for future shelter related studies.

Free access

Abstract:

This paper proposes the application of energy efficient, low tech (passive) building design strategies and concepts in an industrial facility case study, in order to create a building with high efficiency and comfort within the boundaries of a tight investment cost. The planning process is supported by dynamic thermal and daylight simulations. Two versions were considered, a conventional industry building and a low tech one with climate zone based space organization. According to the evaluation of thermal and visual comfort as well as energy demand the selected version with the innovative passive concept delivered considerably better performance. According to the constructor’s concept, the reference building had to be placed by minimal adaptation on the new site. After considering and calling this concept into question, a new ‘energy design’ concept was elaborated at the sketch planning level. The new concept was compared with the reference building and a quantified, simulation assisted evaluation was provided about the cases. Since there was an essential improvement in comfort and energy level and, in addition, at architectural standard, the constructor could have been convinced to accept the new concept.

Open access

Abstract:

Day-lighting studies in buildings play a major role in indoor environmental investigation and can be conducted at the early stages of building design. Window position significantly affects day-lighting performance. This paper assessed the impacts of the window position on the visual comfort through two main factors; daylight factor and light uniformity in the hot and dry climate zone. In this study different window positions have been examined to achieve optimal visual comfort, using a dynamic simulation through Vi-suit plugin for Blender 3D software that controls the external application Radiance software. The results revealed that the window position at sill start from 1.4 m of a room characterized by (4.30 m × 3.00 m × 3.00 m) is the best compromising solution that complies with the daylight factor and light uniformity standards in the indoor environment. The findings of this study provide a more detailed and comprehensive analysis of the window design for architects/designers in the early building design stages in the hot and dry climate region.

Open access

Abstract:

Moment resisting frames are considered as an effective seismic force resisting system that is used for steel structures. Some of these structures that were built in high seismic hazard zones were designed according to old strength-based design codes. Currently, these structures do not meet the requirements of the new seismic codes. Therefore, the seismic retrofit of these structures is mandatory and cannot be overlooked. Steel braces and concrete-steel composite elements are common solutions for enhancing the seismic behavior of existing steel frame structures. This paper presents a numerical study that evaluates different possible techniques for the seismic retrofit of existing steel moment-resisting frame structures. The study investigates the performance of three multi-story buildings with different heights that are located in a high seismic hazard zone. Three retrofit techniques were introduced including; 1) X-Steel braces, 2) buckling restrained composite braces, and 3) composite concrete-steel plate shear walls. The seismic performance enhancement of the studied structures was evaluated in terms of the structure’s fundamental period, maximum inter-story drift and maximum base shear-to-weight ratios. Moreover, the cost of retrofitting material was estimated for each technique and they were compared to select the retrofit technique with the least constitutive material cost.

Open access

Abstract:

In this study the detailed One-at-a-Time sensitivity analysis of nonlinear mass spring-damper systems is carried out with numerical simulation. The degree of sensitivity was measured with a sensitivity index and based on its sensitivity Fuzzy-sets were established. The sensitivity of a parameter then can be expressed by the membership to the Fuzzy-sets. In this study the root mean square of acceleration, the maximum amplitude of acceleration and the peak frequency were chosen as output variables to measure sensitivity. With this research it was proven, that the root mean square of acceleration and the peak frequency can be used for sensitivity study of nonlinear vibration systems effectively.

Open access
International Review of Applied Sciences and Engineering
Authors: Ahmed S. Al-Zuhairi, Alaa H. Altimimy, Ali T. Al-Aqbi and Hazim M. Al-Kargole

Abstract

Growing ramification in WSN contemplations are not restricted to routing, construction of protocols, dynamic of mobile nodes and infrastructure of the network. Although transcended to geometric level demonstrated as computational and dynamical geometries in spite of graph theory. In this paper we present step forward recognition features of a network devoted to solve the problem of reconstructing the disconnected network by connecting any disconnected chains. It considers geometrical properties of random depletion nodes deviated from unit grid. Number of chains and number of nodes in each chain are calculated with the average number of connections to a total nodes and longest chain. Histogram represented number of chains and numbers of nodes for each chain are used to show fragmentation of the network. Algorithm included a method to translate adjacent matrix to chain matrix and vice versa to check the agreement of initial case with the results. The amount of chain deviation and average connections per node for longest connected chain and for the total network are drawn as bar charts and conduct interpretations.

Open access

Abstract

The main cause of train derailment is related to transverse defects that arise in the railhead. These consist typically of opened or internal flaws that develop generally in a plane that is orthogonal to the rail direction. Most of the actual inspection techniques of rails relay on eddy currents, electromagnetic induction, and ultrasounds. Ultrasounds based testing is performed according to the excitation-echo procedure []. It is conducted conventionally by using a contact excitation probe that rolls on the railhead or by a contact-less system using a laser as excitation and air-coupled acoustic sensors for wave reception. The ratio of false predictions either positive or negative is yet too high due to the low accuracy of the actual devices. The inspection rate is also late; new numerical method has been developed in this context: The semi-analytical finite element method SAFE. This method has been applied in the case of anisotropic media [], composite plates [] and media in contact with fluids []. This method has been used successfully for several structures and especially in the case of beams of any cross-section such as rails that are the subject of this work and we were interested in wave propagation in waveguides of any arbitrary cross-section in the case of beams or rails.

Open access

Abstract

Direct sequence spread spectrum (DSSS) communication systems offer huge performance focal points in perspective on their low probability of block, improved performance in multipath fading situations and their capacity to stay away from interference by spreading the signal over a wide bandwidth subsequently conveying the power. For the transmitted sequence to be effectively received and demodulated, the spreading sequence utilized at the receiver ought to be like that utilized in the transmitter. This paper uses MATLAB Simulink to show a technique for synchronizing the code clock at the receiver with the code clock at the transmitter. This fine arrangement procedure is known as code tracking.

Open access

Abstract

Due to the extensive development of high-speed railway lines which are operating at increasing velocities, the dynamic performance of railway bridges has become an important issue of scientific research. The aim of this study is to investigate the possibility of reducing the vertical acceleration and displacement of pre-stressed reinforced concrete bridges beams by using passive nonlinear viscoelastic dampers to retrofit them. The proposed solution is based on connecting the dampers directly to the abutments and the bottom surface of the bridge deck with an eccentricity between the neutral axis of the bridge and the contact point of the viscoelastic dampers. First, the dampers are modeled through the concept of linearized fractional derivatives to obtain energetic equivalent linear viscoelastic dampers. Optimization of the configuration of these dampers was performed then as function of the orientation angle and the eccentricity. Considering two bridges having different length that were studied in the literature with other systems of damping, it was found that the best orientation angle of dampers is close to 60°. It was found also that, in order to satisfy Eurocode 1 requirements, the total equivalent damping coefficient for the actual damping system is less than half of that required for systems using auxiliary beam to fix dampers, which indicates higher efficiency of the proposed solution.

Open access

Cells and building structures. Part I.

Cells – point-like, line-like and surface-like bodies – building structures

International Review of Applied Sciences and Engineering
Author: Géza Lámer

Abstract

The rooms of each building can be interpreted as three-dimensional cells. Borders (sides, edges) of rooms can be identified as the two-, one-, or zero-dimensional boundary cells of the three dimensional cell. The building structures identified as two-, one-, or zero-dimensional cells can be modeled by distinguished geometrical forms, surface-, line-, and point-like bodies. In accordance with the latter, building materials (finished products) can also be considered as surface-, line-, and point-like bodies.

The aim of the study is to create compliance between the cell elements and the building structures. It will be done at different levels:

  • – interpretation of relationship between building construction and cells,
  • – interpretation of relationship between building construction and selected bodies,
  • – interpretation the loadbearing's structure using cells,
  • – structure of the surface-construction and the cells,
  • – interpretation building types using cells.

In this paper (as part I) the first two items will be studied. The other three cases will be studied in another paper (as part II).

Open access

Abstract

The research team has developed a complex system that is capable to record and analyse various psychophysiological data. This article represents the program created in NI DIAdem which can automatically identify illnesses and generate reports based on the input and saved parameters. The created program can import data from different types of file formats. It is converted and saved in a new standardized format for further processing. It can play-back the processed data synchronized with adjustable speed, and visualize them on customized display areas. It can analyse the data based on the input parameters and the pre-defined mathematical equations. The program displays the input and calculated parameters, the results and the detected illnesses on automatically generated reports.

Open access

Abstract

The objective of this paper is to present a proposed control model for the electromechanical damper mass spring system including the backstepping technique in comparison with the conventional proportional–derivative–integral (PID) controller unit to realize the best performance of the control systems. The suggested approach demanded the construction in laboratory arrangement of damper mass spring system which linked with electrical position sensor, and the theoretical work involved the derivation of the required mathematical equations in order to formulate the simulation models in Matlab software package. The obtained results show that the backstepping control technique provides the better performance associated with stable control system especially with increasing the value of selected mechanical load.

Open access

Abstract

In the recently published researches in the object localization field, 3D object localization takes the largest part of this research due to its importance in our daily life. 3D object localization has many applications such as collision avoidance, robotic guiding and vision and object surfaces topography modeling. This research study represents a novel localization algorithm and system design using a low-resolution 2D ultrasonic sensor array for 3D real-time object localization. A novel localization algorithm is developed and applied to the acquired data using the three sensors having the minimum calculated distances at each acquired sample, the algorithm was tested on objects at different locations in 3D space and validated with acceptable level of precision and accuracy. Polytope Faces Pursuit (PFP) algorithm was used for finding an approximate sparse solution to the object location from the measured three minimum distances. The proposed system successfully localizes the object at different positions with an error average of ±1.4 mm, ±1.8 mm, and ±3.7 mm in x-direction, y-direction, and z-direction, respectively, which are considered as low error rates.

Open access

Abstract

The fourth industrial revolution, often identified as the terminology of Industry 4.0, more and more enforces changes and modifications from each participant of the socio-economic ecosystem. These enforced corrections concern the households, the governmental areas in different degrees, but the operation of the company sectors is rearranged most strongly by them. The study analyses this latter structure in the following respect: which are the most important supports of Industry 4.0 and what kind of competency elements are required from the employees and the management? According to the research data to be introduced, the domestic companies lag behind in preparations for the challenges raised by Industry 4.0; the international experiences are more favourable in this field. After—partial—review of the professional literature, the author concludes that the business sphere is in a condition before paradigm shift due to Industry 4.0. As per the analysis of decision-making based on digitalization, the question in the subtitle is answered—Industry 4.0 does not change fundamentally the traditional management functions of the company sector, but the decision-supporting applications based on digitalization must be learnt and applied. That statement seems to be founded that only company management, being able to live with decision making based on digitalization, can win competitive advantage.

Open access

Abstract

Today, the use of proportional-integral-derivative (PID) control units continues in many control applications due to their simple structure. In areas such as pressure, temperature, flow control, PID control element is used and many new methods are applied in adjusting control parameters. In this study, the LTR 701 Controlled Airflow and Temperature Experimental System was used to study the temperature and pressure control at different flow rates in the pipelines. In this control system, temperature was controlled with PID control element, pressure was controlled with PI control element, and reaction of control parameters at different temperatures and pressures were investigated. Also, temperature was controlled as cascade with PI element in elementary controller and P element in secondary controller. The manual adjustment method has been applied to adjust the control parameters. In addition, the experimental system is modelled in MATLAB-SIMULINK. On this model, simulation results showed that it is matching the experimental results.

Open access

Abstract

In this work a multilevel Computational Fluid Dynamics (CFD) analysis has been applied for the design of a Formula race car exhaust muffler with improved characteristics of sound pressure level (SPL) and fluid dynamic response. The approaches developed and applied for the optimization process range from the 1D to fully 3D CFD simulation, exploring hybrid approaches based on the integration of a 1D model with 3D tools. Modern mufflers typically have a complex system of chambers and flow paths. There are a variety of sound damping and absorbing mechanisms working to quiet the sound flowing through a muffler and piping system. Two calculation methods were selected for this study. The muffler has a complex inner structure containing perforated pipe and fiber material. Computer-aided design (CAD) file of the muffler was established for developing Finite Element Analysis (FEA) model in AVL BOOST v2017 and another commercial advanced design software (SolidWorks 2017). FEA model was made to monitor the flow properties, pressure and velocity. After the model was verified, sensitivity studies of design parameters were performed to optimize the SPL of the muffler. The software analysis results are included in the paper. Recommendations are made for obtaining smoother SPL curves for various measurement methods.

Open access

Abstract

In this work, a numerical method is proposed in order to achieve design optimisation of phased array (PA) probes for the special application of defects detection in thin films. This approach relies on an extended Fourier-based model that was adapted to predict the two-dimensional ultrasonic displacement field taking place in a thin plate under individual excitation of PA probe elements which have arbitrary orientation with respect to the examined part surface. Excitation is applied through a fluid couplant and is operated at scheduled delays that are managed to enable emission of constructive pulses. This gives the possibility to steer sound waves towards a direction and to focalize the beam in a selected point. An optimisation algorithm based on the concept of pattern search that does not require evaluation of a gradient was used to find the best match in the multidimensional analysis space of possibilities including the elements orientation angles, the elements lengths, the inter-elements distances and work frequency. Optimisation was performed with the objective to maximize the displacement amplitude at the focal point while minimizing simultaneously the effect of beam side lobes. The results obtained by this approach reveal that focalisation can be achieved with enhanced features in comparison with previous algorithms assuming linear elements that are parallel to the surface of the plate.

Open access
International Review of Applied Sciences and Engineering
Authors: Norbert Novák, Péter Miklós Kőmíves, Mónika Harangi-Rákos and Károly Pető

Abstract

The role of rural areas partly changed in the last decades. The countryside is still functioning as the main food producer of the world and this role became much more important because of the global population growth and because of the change in dietary habits. But other rural functions appeared just like recreation, health preservation, and on the other hand the different ecological functions' importance increased. The population living in the countryside is continuously decreasing as more and more people try to move into urban areas. One of the main aims of this article is to give a brief literature overview on the services needed in the rural areas in order to stop migration from the countryside to the cities. Based on extensive literature review the article summarizes the changing functions of the countryside and tries to list those developments which are needed to preserve rural population.

Open access

Abstract

In the building mechatronics research centre of University of Debrecen, Faculty of Engineering, a new laboratory has been designed, named “Cyber-physical and intelligent robot systems laboratory”. The possibility to design and test unique and platform-independent systems was among the main goals, hoping that the system itself and its advancements may later be used in manufacturing industries as well.

Fulfilling the needs of “Industry 4.0” is a challenging task, as it requires every single device (e.g. industrial robots) to be connected to the same network, where they may be monitored and controlled. However, there are some factors that limit this, such as the periodical “instability” that some machines have, caused by singularity points.

The following material studies these so-called singularities of a KUKA KR5 industrial welder robot placed in a robot cell, from an engineering viewpoint.

Open access

Consumer concern over artificial food additives has stimulated production of pigments from natural sources. The aim of this study was to examine the effects of process variables on the content of colour compounds (betaxanthin and betacyanin) in beetroot peel juice extracted by conventional method. In this research, the extraction processes were carried out according to the central composite design with different process variables. Quantitative measurements of the basic colour compounds in beetroot extract were performed using spectrophotometer. From our experiment, it was found that the most adequate extraction conditions, which gave the highest yield of colour compounds (952.5 mg l–1 of betaxanthin and 1361 mg l–1 of betacyanin), were extraction time 1 h, operating temperature 20 ºC, and solvent ratio 0.8 w/v. Being a conventional heating method, it is a simple and cost efficient process with relatively high yield.

Open access

Tomatoes (Solanum lycopersicon L.) are one of the most important and most widely consumed vegetables in the world. The fruit contains considerable amount of different phytonutrients such as carotenoids, tocopherols, and vitamin C. In the present work, effects of some abiotic factors on the concentration of phytonutrients were investigated in tomato cultivated in two different types of soil. It was found that the type of soil had slight effect on the most important vital nutrients, while the ecological factors, particularly precipitation and average temperature 3 weeks before harvest, were of significant influence on such nutrients. It was found that low temperature and high precipitation before harvest caused the levels of carotenoids, tocopherol, and vitamin C to significantly increase by 65%, 46%, and 28%, respectively.

Open access

Changes of edible oil quality factors and formation of 3-monochloro-1,2-propanediol fatty acid esters (3-MCPD-FE) during deep-fat frying in four different experiments (control, salt, pork chop, and chicken liver) with high oleic sunflower oil were compared in this study. Based on the results of investigated oil quality parameters, which were free fatty acid (FFA), anisidine value (AV), UV extinction at 232 and 268 nm (E232 and E268, respectively), and total polar material (TPM), only a modest deterioration of the frying oil was observed. As we expected, the 3-MCPD-FE content in the control samples did not reach the limit of quantification (0.1 mg kg–1), while the table salt itself caused a slight increase. The results of pork chop and chicken liver experiments were not statistically different from each other, after the third frying circle 0.52 and 0.39 mg kg–1 3-MCPD-FE levels were reached, respectively. Based on these values, the human exposure estimation resulted in a low risk.

Open access
Acta Alimentaria
Authors: E. Horvath-Szanics, J. Perjéssy, A. Klupács, K. Takács, A. Nagy, E. Koppány-Szabó, F. Hegyi, E. Németh-Szerdahelyi, M.Y. Du, Z.R. Wang, J.Q. Kan and Zs. Zalán

The increasing consumer demand for less processed and more natural food products – while improving those products’ quality, safety, and shelf-life – has raised the necessity of chemical preservative replacement. Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Chitinolytic enzymes are of biotechnological interest, since their substrate, chitin, is a major structural component of the cell wall of fungi, which are the main cause of the spoilage of food and raw plant material. Among the several organisms, many bacteria produce chitinolytic enzymes, however, this behaviour is not general. The chitinase activity of the lactic acid bacteria is scarcely known and studied.

The aim of the present study was to select Lactobacillus strains that have genes encoding chitinase, furthermore, to detect expressed enzymes and to characterise their chitinase activity. Taking into consideration the importance of chitin-bindig proteins (CBPs) in the chitinase activity, CBPs were also examined. Five Lactobacillus strains out of 43 strains from 12 different species were selected by their chitinase coding gene. The presence of the chitinase and chitin-biding protein production were confirmed, however, no chitinolytic activity has been identified.

Open access

Immature rice grain is one of the under-valued by-products of rice milling industry. In this study, it was aimed to investigate the effects of immature rice grain flour (IRGF) substitution to tarhana, which is a traditional cereal-based, fermented food product. IRGF was replaced by refined wheat flour at the levels of 0 (control), 30, 50, 70, and 100%, and the effect of this replacement on the contents of crude fat, ash, protein, dietary fibre, phytic acid, minerals, vitamins B1 and B2, tocopherols, γ-oryzanol contents and sensory properties were investigated. It was shown that stabilised IRGF remarkably improved nutritional properties of the end product without adversely affecting sensory quality up to 50%. In conclusion, it could be suggested that stabilised IRGF has a promising potential for many food applications due to being cheap, accessible, nutritious, and gluten-free.

Open access

Abstract

The sol gel method was used in preparing a series of A site partially substituted La1−xBaxCoO3 (x ≥ 0.1 ≤ 0.4) perovskite catalysts coded LBC1, 2, 3, and 4 and their potential as catalysts for soot oxidation were evaluated. The Brunauer–Emmett–Teller (BET), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES), Thermogravimetric/Differential Thermal Analysis (TGA/DTG), X-ray analysis (XRD) were used in characterizing the prepared perovskite catalyst. The result shows that at (x≥ 0.2 ≤ 0.4), there was an increase in surface area when we compare it with that of x = 0. The increase in surface area helps in increasing the catalytic performance of the catalyst. Also, when evaluating the catalytic performance of the synthesized catalysts, it was observed that doping the perovskite catalysts helped in the general improvement of the catalytic performance for soot oxidation. The best performance in this research study with a T50 of 484 °C was observed at x = 0.2 catalyst (LBC2). This shows that the non-noble perovskite catalysts prepared in this research study has the potential to replace the noble metal based catalysts used presently in the diesel automotive industry.

Open access

Abstract

Though being an ancient trend, usage of the homogeneous material cement in the construction industry is steadily getting eradicated with the springing up of supplementary cementing materials (SCM). Metakaolin is an imminent mineral admixture extracted from the mineral ore kaolinite, which enhances the interfacial zone by more efficient packing at the cement paste-aggregate particle interface, thus reducing the bleeding and producing a denser, more homogeneous transition zone microstructure. This paper depicts the various repercussions of the pozzolanic material metakaolin in the fresh and hardened properties of concrete when replaced with cement in finite amount. Also, it states the behavior of high-performance concrete and self-compacting concrete with metakaolin.

Open access

Abstract

The inelastic buckling behaviour of different rectangular thin isotropic plates having a free edge is studied. Various combinations of boundary conditions are subject to in-plane uniaxial compression and each rectangular plate is bounded by an unloaded free edge. The characteristic deflection function of each plate is formulated using a polynomial function in form of Taylor–Maclaurin series. A deformation plasticity approach is adopted and the buckling load equation is modified using a work principle technique. Buckling coefficients of the plates are calculated for various aspect ratios and moduli ratios. Findings obtained from the investigation are found to reasonably agree with data published in the literature.

Open access

Abstract

Industry 4.0 is referred as the fourth industrial revolution that represents the information intensive transformation of industrial automation and manufacturing processes. Cyber-physical systems (CPS) are building blocks in Industry 4.0 and part of the Industry 4.0 vision. This paper presents a cyber-physical platform development and implementation strategy for Industry 4.0 applications. It has been considered a cyber-physical platform model (CPP) built upon hardware reconfigurable technology based on a Field Programmable Gate Array (FPGA) processor framework. The development strategy exploits the full benefits enabled by reconfigurable hardware, such as scalability of complex systems, platform-based design approach, adaptive processing, real-time constrains management, or high performance prototyping capabilities. The implemented experimental setup also combines major advantages of both the hardware and software platform-based design trends in Industry 4.0. In this endeavor, the used software toolkit comprises the entire system complexity as a high performance integration layer. The presented design method and implementation strategy can serve as rough orientation for future CPS research and development activities.

Open access

Abstract

Reliability is one of the most important criteria that characterize last generation digital systems. In a wide range of applications the required reliability level is achieved by using hardware redundant configurations. Perhaps their most common form is the triple modular redundancy (TMR) based on a majority voting structure. Researchers that use this strategy make a major assumption: in fault-free operation mode the outputs of these digital systems match in all. This paper proves that synchronization and matching in all the outputs of such systems is not such a trivial problem. In this endeavor FPGA-based (Field Programmable Gate Arrays) redundant topologies are considered for study and experiments. Upon these structures specially conceived redundant models have been developed and simulated. The results outline that synchronization of complex digital systems is a difficult engineering undertaking and any initial assumption should be managed with the adequate circumspection.

Open access

Abstract

Information management and sharing is an essential ingredient, but a difficult and challenging problem for disaster response management. This paper proposes an ontology as a model to organize and structure information in order to improve the information management and sharing in disaster response management. The ontology was designed and developed based on philosophically grounded foundational ontologies. It was also implemented in ontological languages and demonstrated and evaluated in a case study of the flood evacuation process. This paper also provides a systematic approach to develop a well-founded domain ontology that addresses both static and dynamic aspects of a given domain.

Open access