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Abstract

Nowadays heuristic methods are one of the most used tools for the optimization of problems. The proof of that is the fact that they are widely used in chemistry, economics and energy. Among the most popular of heuristic methods belongs differential evolution, belonging to the so-called ‘evolutionary algorithms’. They can handle difficult, large-scale problems with many parameters, like the optimization of the hydro-thermal coordination of hydro and thermal power plants. As with any other method, differential evolution also has certain parameters. These parameters, among others, are the size of the population, the maximum number of generations, crossover parameter and mutation factor. The effect of these parameters on the results of an optimization using differential evolution is the focus of this paper. The hydro-thermal coordination of one hydro and one thermal power plant was used as an example to explain this issue.

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Abstract

As streets cover almost twenty-five percentages of the urban open spaces, designing streets is a vital issue in creating thermal comfort for urban environmental design. The geometry of the street (height/width ratio) as well as orientation directly influences the airspeed, solar access in urban canyon and as a result thermal comfort at the pedestrian level. This study examined the street geometry case study's scenarios with different street geometries and investigates its effects on outdoor thermal comfort as well as the weather parameters. However, according to the matrix assessment conducted by the author, the vast street canyons (height/width=0.65 m/14.5 m with an orientation parallel to the prevailing wind direction achieved the best results. Nevertheless, the aim of this paper is to investigate the impact of street canyon geometry on outdoor thermal comfort and its parameters in the summertime using numerical modeling.

Open access

Abstract

This research aims to evaluate the effectiveness of implementing quantitative techniques to improve decision making in construction projects by using time- and cost-oriented failure mode and effect analysis and Monte Carlo simulation. This research is limited to the project schedule and risk management of one phase of a construction project to build a new automated warehouse in Hungary. The results show that there are 80% and 100% chances that the duration and cost of the construction project phase will increase due to the uncertainty and individual risks associated with the construction project activities respectively.

Open access
Authors: M. Atanacković Krstonošić, J. Cvejić Hogervorst, Lj. Torović, V. Puškaš, U. Miljić, M. Mikulić and Lj. Gojković Bukarica

Most of red wine's health benefits are attributed to polyphenols, which can express different biological effects. During ageing process, numerous chemical reactions occur, alternating phenolic composition of wine. Therefore, this paper focused on the influence of ageing on the evolution of wine phenolics (phenolic acids, flavonoids, stilbenes, and anthocyanins). Wines from 4 local grape varieties (Frankovka, Portugieser, Probus, and Rumenika) were analysed after 1 month and 4 years of ageing. Monomeric anthocyanin and total phenolic contents and antioxidative potential in aged wines were also determined. Among tested phenolics, main components in aged wines remained gallic acid (2.16–19.55 mg l−1) and catechin (8.39–37.21 mg l−1). The most prominent changes of analysed phenolic compounds during ageing were observed for p-coumaric acid (from +173.3% to +763.1%) and malvidin-3-glucoside (from +173.3% to +763.1%). Wine from Rumenika variety maintained the highest content of individual phenols after ageing. Additionally, aged wines had very low content of monomeric anthocyanins. Significant correlation (r= −0.93, P<0.05) between total phenolic content and IC50 values in aged wines was also noticed. Obtained results provide useful information about the quality preservation during aging and storage of these products.

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Abstract

In this paper a detailed description of a method is presented to estimate the minimum structural dimensions of the robot arms. A comparative study is conducted between the harmony search and artificial bee colony algorithms in this scientific application. The comparison process was done through the kinematic equations of the serial robot manipulator to find the optimum lengths of links of the robot. A novel design for a seven-degrees-of-freedom robot arm was presented to conduct the comparative study on the presented optimization algorithms. This novel robot mimics the functionality of the SANDVIK robot arm for tunnelling works, but the presented type synthesis was designed to overcome the restrictions on the original SANDVIK arm.

Open access

User experience is vital in usability evaluation to understand all aspects of user interactions with a product or system. The usability includes user satisfaction, efficiency, and effectiveness to achieve certain goals. On the other hand, to support the sustainability of the business, it is necessary to know the factors that significantly affect purchase intention through online travel booking application. The main aim of this paper is to investigate the usability of online travel booking system and consumer-level factors of purchase intention in online travel booking application. The research attempt to find whether product diagnosticity influences perceived quality and product trust and generally impacts purchase intention. In this study, we select an existing online travel booking application named Traveloka. The system usability scales (SUS) were used to evaluate the usability for web applications. A total of 1,225 respondents participate in online questionnaire using Google form. Most of the respondents recruited are based in Jakarta, Indonesia. The overall SUS score is only 56.13 from 100. The results show that intention for purchase is influenced by product trust and perceived quality. Moreover, the product diagnosticity (PD) supported perceived quality (PQ) and product trust (PT), and variable of product trust (PT) also supported perceived quality (PQ).

Open access
Authors: Daniel Buček, Martin Orfánus and Peter Dušička

Abstract

This paper presents a proprietary open source code for analysis of granulometric properties of bed load material based on non-intrusive automated image analysis. Vertical bed-surface images are processed using the proposed tool and verified with results obtained by well tested optical granulometry tool Basegrain. The practical application of the proposed tool yields accuracy comparable that of the tested framework and traditional sampling methods. Additionally, results showed that the average D50 grain-size sampled from riverbed of studied river section of river Danube agrees up to 95% with the average D50 sampled from riverbanks.

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Authors: K. Solichová, I. Němečková, E. Šviráková and Š. Horáčková

Fifteen strains of Bacillus spp. (three B. cereus strains, one B. subtilis, B. macerans, B. pumilus, and B. mycoides strains, and eight unknown isolates from the food-industry) were identified on species level with three designed pairs of primers for B. cereus, B. licheniformis, and B. subtilis. Primers designed for B. licheniformis (BlichF and BlichR) and B. subtilis (BsubF and BsubR) allowed specific species identification, whereas the designed pair of primers for B. cereus (BcerF2 and BcerR2) showed specificity for B. cereus sensu lato, because both B. cereus strains and B. mycoides gave positive reaction. Bacilli identification was also carried out with routine API method with unsatisfactory results. The (GTG)5-PCR method was used for strain characterization, enabling bacilli classification into separate clusters according to their taxonomic designations.

Open access

Due to the ISM band being unlicensed for communication applications, a lot of applications have been developed in this band and a good example is WiFi IEEE 802.11a, b, g, n of Bluetooth. This numeracy of applications motivated this paper. The paper is concerned with the design of a low distortion 20 dBm 2.4 GHz class-J power amplifier (PA) since PAs are indispensable in radio communications. The design is based on the AVAGO ATF-52189 transistor with a transition frequency of 6 GHz. The design is done as a hybrid circuit network realized using microstrip elements and surface mount device (SMD) capacitors. The schematic design and simulation are carried out using Keysight's Advanced Design System version 2016.01. The simulated PA exhibited a drain efficiency of 69% and a power output of 21 dBm.

Open access

Providing quality requirements in Software Engineering is vital to ensure the product developed is able to deploy and function to meet the operational objectives. Software Requirement Engineering is the most complex process because it involves the integration of human, logics and process. Extracting or capturing what customers need and want is called Requirement Elicitation (RE) and it is the most crucial process in requirement engineering. If handled poorly, the cost of the failures would be very expensive. Most of the software projects that failed were due to poor requirements which occurred at RE phase. Thus, enhancing and optimizing the RE methods have been subject to a long research debate to ensure quality requirements are captured. Recently, Lean Six Sigma (LSS) had emerged as part of a continuous improvement in Software Development Life Cycles (SDLC). LSS is known for a systematic and structure business improvement successfully deployed in many fields of industry that contributes a significant gain not only in quality of products and services but also in operational costs and delivery. The objective of the research is to develop an integrated conceptual framework of LSS principles with Software Requirement Engineering methodology to optimize RE process. The article will produce conceptual framework as the comprehensive guidelines to capture quality software requirements.

Open access
Authors: Flóra Hajdu, Péter Szalai, Péter Mika and Rajmund Kuti

Abstract

In case of field measurement it is essential to determine the measurement conditions. With accurate parameter identification credible measurement and simulation results can be achieved. In this paper the parameter identification of a CSD-755-10 heavy-duty fire truck suspension for vibration analysis is presented, which is an important base-point for further research.

Open access

Skin-contact fermented white wines, the so-called orange or qvevri wines, have been gaining international attention from winemakers, importers, sommeliers, consumers, and journalists over the last 10 years. Sommeliers are now regularly pairing orange wines with fine cuisine. This new culinary trend is part of a general move by the consumer wishing to respect the existence of traditions and innovation, combined with a growing interest in environmental awareness and healthy options. Orange wines are made from white grapes using ancient Georgian techniques. The essence of this method is the long skin-contact fermentation in amphorae without any chemicals or specific yeast. In our work, the polyphenol content of orange wines, in particular total polyphenol and catechin content, as well as colour intensity were measured to ensure safe winemaking technology without oxidized components.

Open access

Abstract

The aim of the paper is to discuss the post-conflict reconstruction of cultural heritage properties and involvement of peace agreement into a return of refugees and reconstruction of destroyed cultural heritage. Examples of monuments: Emperors mosque in Stolac, Handanija mosque in Prusac, Kujundžiluk bazar in Mostar near Old Bridge in Mostar (UNESCO site), Monastery in Zavala and Land museum in Sarajevo. An investigation focus is on results of the survey on the assessment of the impact of organization cultural heritage without borders engagements in Bosnia and Herzegovina. Reflection of the economic situation in Bosnia and Herzegovina, rather on attitude towards reconstruction of cultural heritage properties of importance.

Open access

The aim of this study was to investigate the occurrence of Salmonella enterica and its most important serovars Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, and Campylobacter spp. in the broiler meat production chain. Altogether 110 pooled samples were analysed; environment, cloaca, body surface at the farm, then carcass, offal, and packed meat from the slaughterhouse. The combination of redox potential measurement and realtime PCR was used for the detection of the microbes.

At the farm, the first Salmonella positive result came from the water system, then it appeared in most of the samples. In contrast to the absence of Salmonella on the birds’ body surface before transportation, by the end of the processing it had reached 100%, with the only identifiable serovar being S. Infantis (65%). All packed meat samples showed positivity, from which 70% was S. Infantis.

Campylobacter appeared at the farm on the 3rd week and remained significant during the breeding. After the slaughtering process, the contamination was 100% in the carcass, offal, and packaged meat samples.

Our results demonstrated the success of the Salmonella control program, by the low prevalence of S. Typhimurium and Enteritidis.

Open access

The comparative efficacy of 0.4% carboxymethyl cellulose (CMC) and 0.3% sodium alginate (SA) was evaluated as fat replacer in low-fat (<0.5% milk fat) mozzarella pre-cheese on the basis of physico-chemical, processing, textural, and colour profile, nutritional and sensory attributes. High-fat mozzarella cheese (prepared from milk with 6.0% fat) was taken as control (FFMC), whereas low-fat mozzarella cheese (prepared from milk with <0.5% fat) without any fat replacer (LFMC) taken as negative control. The per cent yield was lower in low fat cheese with CMC (LFMC-CMC), whereas in low fat cheese with SA (LFMC-SA) it was comparable with FFMC. The moisture and protein contents were higher (P<0.05) in low-fat mozzarella cheese (LFMC-CMC, LFMC-SA) than in FFMC. The energy content in LFMC-CMC and LFMC-SA was 44 percent lower than in FFMC. The meltability decreased, whereas melt time increased in LFMC-CMC and LFMC-SA compared to FFMC. The processing and nutritional attributes were comparable in both treatments. Hardness increased, whereas chewiness decreased in low-fat cheese. However, type of fat replacer did not affect hardness of the product. Gumminess was higher (P<0.05) in LFMC-CMC than in LFMC-SA. The sensory panellists rated LFMC-SA better for flavour and overall acceptability than LFMC-CMC. The appearance, texture, and juiciness were comparable in low-fat and high-fat mozzarella cheese. Results indicated that 0.3 per cent SA can be successfully used for processing of low-fat cheese.

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Casein peptides with calcium-chelating capacity were rapidly enriched by using a novel ceramic matrix (CM)-based Ti4+-IMAC adsorbent. The ability of calcium-chelating peptides (CCPs) to bind calcium and the physical properties of complexes formed between CCPs and calcium were investigated. Results demonstrated that the amount of calcium bound depended on the degree of hydrolysis (DH) of casein hydrolysates. The highest calcium binding capacity (683 mg g−1) occurred when bovine casein was hydrolysed by pancreatin at a DH of 0.14%, meanwhile, the calcium content of CCPs-Ca complex exhibited the maximum level (134.96 mg g−1). In addition, CCPs showed a higher radical scavenging capacity (50 µg ml−1; 99% inhibition, or an equivalent activity of 9.91×10−3 M Trolox) compared to casein digest. Moreover, Fourier-transform infrared spectroscopy and fluorescence spectroscopy were used to explore the interaction between CPPs and calcium, and the results demonstrated that phosphoserine residues as well as COO- groups of CCPs were involved in the formation of CCPs-Ca complex.

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In heat transfer calculations, transmittance values are often used as a constant in practice. With the spread of dynamic simulations, it opens an opportunity to study the sensitivity of the external effects (e.g., wind speed) on buildings. With the proper amount of result, adequate simplifications can be made to reduce the duration of the simulations. In this paper several steady sate simulations were carried out by Ansys 19.1. Academic version. In the examined cases three building structures were examined with different thermal resistances. Average initial air temperature difference was applied on the two sides of the structures, at the cold side the wind speed was varied, while at the warm side natural convection was present. The surface temperatures and the heat flux were monitored and the transmittances were calculated as a result.

Open access
Authors: Klára Czimre, Gábor Kozma, Károly Teperics, György Szabó and István Fazekas

The growing significance of renewable energy resources has been one of the most important processes in the field of energy management for the past two decades. This is due to phenomena related to environmental protection, security of supply, economic and rural development, as well as to the abundance of financial incentives (EU grants, constructive national off-take regime). As a consequence of this, the paper concentrates on the general and territorial characteristics of the EU financial instruments for Hungary in the 2007–2013 budgetary period with the objective to enhance the dissemination of renewable energy resources. As an outcome of our research, three very important conclusions were drawn. First of all, less developed regions were more active in submitting proposals though the more developed regions reached higher success rates. Secondly, it was noticed that the “identity” of the successful tenderers influenced the average volume of proposals to a considerable extent. Thirdly, in the case of the successful proposals, the development level and size (of settlements) of the territorial units (districts) had a direct impact on the identity of the applicants and on the average size of proposals.

Open access

Double skin façades are façade technologies that have the perspective of reducing energy use and improving comfort in buildings due to their adaptable nature. Exhaust-air façades offer the possibility to utilize solar energy by recovering heat from the façade cavity. However, the cavity overheating can be detrimental on the summer performance. Predicting performance and optimizing the system during the design phase is a challenge, especially when the cavity-air is integrated into the HVAC system. Whole-building energy simulation (BES) software tools are an adequate tool for calculating whole building performance, although these can have limitations in the accurate replication of complex building elements. The paper analyses the available and applied modelling approaches within a BES tool, and compares the outputs in terms of cavity temperature, horizontal and vertical temperature profiles, and heat flux through the façade. The sensitivity of the results on the modelling approach is evaluated. Results can serve as a guide for practitioners on the selection of the modelling approach for a given task.

Open access
Authors: Muhanned Al-Rawi and Muaayed Al-Rawi

Frequency hopping spread spectrum (FHSS) communication systems offer significant performance advantages in view of their low probability of intercept, improved performance in multipath fading environments and their ability to avoid interference by hopping into low interference frequency channels. For the transmitted sequence to be correctly received and demodulated, the frequency hop sequence used at the receiver should be similar to that employed in the transmitter. Code acquisition in frequency hopping attempts to address this problem by providing a frequency hop pattern at the receiver that is nearly identical to that used at the transmitter. Code acquisition brings the alignment between the transmitter and the receiver hop pattern to at least one hop period. In this paper, the serial search code acquisition, which is the first step of synchronization, is studied for frequency hopping spread spectrum (HFSS) system over Rayleigh fading channel. Simulation results show the effect of fading channel on the code acquisition.

Open access

Abstract

The resistance of steel-concrete composite trusses is significantly influenced by shear connection producing interaction between the steel beam and concrete slab. To create the interaction between these structural parts, it is needed to prevent the relative slip at the steel-concrete interface using the shear connectors. Push-out testing can reflect the more real effect of the longitudinal force and reproduce the distribution of the shear force between the steel section and concrete slab. The finite element analysis is used in the paper to investigate numerically this structural system behavior, exploiting finite element computer procedures.

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Solar energy systems have emerged over the last decades as the cleanest and most abundant renewable energy resources available worldwide. Solar trackers are devices specially developed to enhance the energy efficiency of solar energy systems. This paper presents the design and implementation stages of a reconfigurable hardware technology-based two-axis solar tracker platform, specially conceived to improve the energy efficiency of photovoltaic (PV) panels. The main module of this platform is the NI MyRIO ready-to-use development system built upon a high-performance Field Programmable Gate Array (FPGA) processor that controls the entire solar tracker unit. Optimal tracking of the sun movement and obtaining the maximal energy efficiency rate is achieved by simultaneous real-time controlling both the captured sunlight intensity and PV cell temperature magnitudes. In this way, a robust and versatile positioning system has been developed that performs a high precision and accurate tracking pathway. All the control algorithms are implemented there under the LabView graphical programming software toolkit. The final solution boosts in a useful and modularized tracking system that looks useful in a wide range of applications both in industrial and domestic project sites with different power scales.

Open access

Wire ropes or rope strands are one of the most important load carrying components of transportation systems such as bridge, elevator, crane and mine hoisting. Wire ropes must have high tensile strength in order to carry high tensile load. Wire ropes are mainly subjected to axial tensile load in service. This axial tensile load is exerted upon wires of rope or strand. Due to this reason tensile load causes elongation, strain and stress on the center wire (core wire) and outer wires. In this study, theoretical calculations proposed by Feyrer are adopted in order to determine wire loads, stresses, elongations and strains for axially loaded rope strands. An illustrative example is given.

Open access
Authors: Muammel M. Hanon, Márk Kovács and László Zsidai

3D printing of Acrylonitrile Butadiene Styrene (ABS) and Poly Lactic Acid (PLA) were used to prepare specimens utilising fused deposition modelling (FDM) technology. Two colours of PLA filament were printed; white and grey, whereas ABS only in white colour. Determining the tribological properties of 3D printed samples have been carried out, through obtaining the frictional features of different 3D printable filaments. Alternating-motion system employed for measuring the tribological factors. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison among the tribological behaviour of the 3D printed polymers has been investigated. The printed white ABS and PLA specimens show insignificant differences in the results tendency. On the contrary, the grey PLA exhibits a considerable variation due to the incredible growth in the coefficient of friction and wear average as well.

Open access

Abstract

Most accidents in roundabouts occur at the entries, partly due to poor visibility. To analyse this problem a sample roundabout with some visibility obstacles was measured by laser scanner and data were put into a 3D model. The fields of view were studied from the viewpoint heights of car and truck drivers as well. To assess the results, three indicators were defined: the hidden sight distance, the hidden sight triangle area and the angle of hide. These indicators were measured in the point cloud model. Through these indicators the adequacy of visibility conditions can be assessed.

Open access

Abstract

The relationship between water body (fountains) scale and climate parameters like wind speed, air temperature, relative humidity, as well as thermal comfort index was modeled and analyzed via Envi-met code. Taking the water impact and factors analysis as a research object, the factors mainly discussed in this research are square area to water-body area ratio and the location of the water element. However, the computational fluid dynamics simulations were conducted on the following scenarios: 3% (original base case), 6%, and 9% of the total square's area, then the outputs of the two simulation results were compared to the original base case. The results revealed that water scale has a slight effect on the micro-climate of the built environment in the summertime in moderately warm-wet climate zone. However, it is beneficial to adjust temperature and humidity in public spaces of central European cities. Nonetheless, the main aim of this paper is to quantitatively investigate the impact of the water bodies on the urban weather parameters and human thermal comfort under the influence of different scale ratios in Pecs-Hungary.

Open access

Fitness industry is an important segment of sports economy worldwide. The number of registered members in fitness clubs has shown a slow, but steady increase. The key objective of our research is to look into the fitness sector in terms of both the demand and supply sides, from the aspect of the fitness providers, as well as of fitness consumers using these services. We are aspiring to explore the training session attendance-related habits of consumers in the Hungarian fitness sector and investigate the factors, features influencing the attendance of the specific trainers’ sessions. Our research focuses on fitness trainers and leisure-time sportspeople who attend gym sessions and therefore the sample may only include people who meet these parameters. As our primary research method, we used interviews and questionnaire survey among fitness trainers and consumers. We asked a total of 753 leisure-time sportspeople and 261 trainers. Our research covers the study of training habits of fitness consumers and a personality analysis of fitness trainers. We think our research results support our fundamental hypothesis that the competitiveness of gyms could be improved by gathering informations on the consumers training habits and selecting the proper experts (trainers).

Open access
Authors: E. Schall, Zs. Bugyi, L. Hajas, K. Török and S. Tömösközi

Quantitation of gluten in gluten-free products is a great challenge as it is hindered by several factors including the lack of certified reference materials. To resolve this problem, our research group, in cooperation with other international experts, started a series of experiments with the goal of the production of a suitable gluten reference material. As a part of this research, several different wheat cultivars and their isolated gluten proteins were characterized by different methods, including enzyme-linked immunosorbent assay (ELISA). However, we need to know the performance of the ELISA methods used for this special area of research. During the present work we investigated the accuracy and precision of two different ELISA methods for our own laboratory conditions and special sample matrices (wheat flours and gliadin isolate). We have found that the tested performance characteristics of the methods seem to be appropriate on a case-by-case basis, but the long-term measurement uncertainty is higher, which makes it difficult to evaluate the results obtained with the ELISA method for these types of samples.

Open access

The incidence and severity of diarrhoea associated with Clostridioides difficile have been increasing exponentially. In 2014, an outbreak with the hypervirulent ribotype 027 strain was firstly reported in Portugal and, among others, this ribotype have been mainly isolated from animals and food. This study aimed to detect and quantify C. difficile from different meats sold in traditional commerce and hypermarkets in two different cities of Portugal, Porto and Lisboa.

Techniques of quantification and detection of C. difficile were performed, but absence of C. difficile in the 143 analysed samples indicates that, if present, the level of contamination should be very low (below 2 log CFU g−1). Despite the lack of confirmed cases of foodborne diseases caused by C. difficile, the increased CDI incidence suggests that contaminated foods may contribute to C. difficile-acquired infections.

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The volatile compounds of acerola wine were isolated by headspace–solid phase microextraction (HS-SPME) and analysed by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). The composition of acerola wine included 38 esters, 19 alcohols, 16 acids, 8 terpenes, 5 aldehydes, 5 ketones, 3 furans, and 8 miscellaneous compounds. The odour-active compounds were screened by application of the aroma extract dilution analysis and odour activity values. Nineteen odorants were considered as odour-active volatiles, from which methyl 2-methylbutanoate and 2-ethylhexan-1-ol were the most odour-active compounds.

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Transglutaminases catalyse the formation of an isopeptide bond between the group of γ-carboxamides of glutamine residues and primary amine groups of proteins. It is widely used in different food industries in dairy, meat, and bakery products. In this work, the effect of the copy number of gene expression cassette on the extracellular production of pro-MTGase under the GAP promoter in Pichia pastoris was elucidated. Expression vector carrying the Streptomyces mobaraensis pro-MTGase encoded gene was constructed and transformed into the P. pastoris X33. The production of pro-MTGase in single copy and three copies expression cassettes containing clones were compared under the same fermentation conditions. More than 30% enzyme activity was obtained from single copy expression cassette containing clone compared to three copies expression cassettes containing clone. Besides, the amount of the enzyme produced per cell was found to be 24% higher in the fermentation broth of single copy expression cassette containing clone. As a conclusion, there is an inverse correlation between the extracellular production of pro-MTGase and the copy number of gene expression cassette.

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The goal of this work was to wade into the freshness quality and biometric evaluation, by means of distinct statistical descriptive methods, on three fresh catch species of fish, as well as to evaluate the discriminant potential of the variables targeted in the study. The species grass carp (Ctenopharyngodon idella), pacu (Piaractus mesopotamicus), and catfish (Ictalurus punctatus) were caught at a rural property located in the city of Pato Branco, PR, Brazil. These fresh catch were weighed, measured, eviscerated, and cut into fillets for acquisition of biometric parameters. Freshness was judged by the analysis of the total volatile basic nitrogen (TVB-N) value and pH. The comparison between means and medians showed symmetries for biometric measures. Correlations between body measures and fillet yield showed a weak relation regardless of the species analysed, wherein the best equation for predictions was obtained by relating total weight to the fillet's weight. The biometric variables were the best discriminants for the species.

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Polyphenol compounds in grapes and wines are of paramount importance: they have a key role in determining wine quality, and also the beneficial health effects of moderate red wine consumption are well-known. The polyphenol concentration of wines is determined mostly by: a) their concentration in the grapes and b) the production technology, particularly the time and type of aging. Our goal was to determine the trans-resveratrol and anthocyanin contents of Hungarian red wines under different manufacturing conditions, by monitoring the 24-month aging process – using barrique and oak barrels – with semi-annual sampling, without considering vintage. We have chosen to determine polyphenol components that could originate from either the grapes, or be produced during the wooden barrel aging. Both the aging time and the wine variety had non-negligible effects on the changes in the concentrations of the studied components, whereas the wooden barrel type had not.

Open access

Sensory profiles of commercial coffee substitutes were determined and their possible interdependences with antioxidant characteristics (FRAP, DPPH, ABTS, and CUPRAC), total polyphenol content, and colour were investigated and compared to coffees. Statistically relevant relations were revealed between certain sensory attributes, colour, and antioxidant capacity.

Sensory attributes show distinct patterns for coffees, their blends, and substitutes, but no significant differences between substitutes from different raw materials were found, except for chicory. Although coffees have generally higher antioxidant capacities than their substitutes, these latter, especially chicory-based products, are also valuable antioxidant sources, as only half of them had significantly lower polyphenol and antioxidant contents when compared to coffee.

Principal component analysis was applied to reveal possible differentiation pattern between samples, based on both their sensory and antioxidant attributes.

Open access
Authors: M.Y. Jiang, Z.R. Wang, K.W. Chen, J.Q. Kan, K.T. Wang, Zs. Zalán, F. Hegyi, K. Takács and M.Y. Du

After suffering from mechanical injury and fungal infection, grapes are perishable. Botrytis cinerea, the causal agent of gray mould, is a critical pathogen for grapes. In this study, the inhibitory effect of Pseudomonas fluorescens on the formation of gray mould on grapes during the postharvest storage was investigated on “Kyoho” grape. The results suggest that a living cell suspension of P. fluorescens significantly inhibited spore germination of B. cinerea, and significantly reduced the incidence of grape gray mould. Moreover, compared with the control, the fruit inoculated with P. fluorescens had elevated activities of polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT), phenylalanine ammonia-lyase (PAL), chitinase (CHI), and β-1,3-glucanase (GLU). Increase in enzyme activity correlated with enhanced host resistance. In addition, there was little difference in storage quality between the treated group and control group, indicating no adverse effects of the induced defence response on fruit quality.

Open access
Authors: E. Ivanišová, K. Meňhartová, M. Terentjeva, L. Godočíková, J. Árvay and M. Kačániová

The aim of the present study was to determine the microbial composition, antioxidant activity, and content of phytochemicals in prepared kombucha tea beverage. Microbiota was identified by MALDI-TOF mass spectrometry, antioxidant activity of beverage was tested by ABTS and phosphomolybdenum method, the total content of phytochemicals (polyphenols, flavonoids, and phenolic acids) was measured by colorimetric methods. The major phenolic acids, flavonoids, and methylxanthines were detected by high performance liquid chromatography (HPLC). Candida krusei, Sphingomonas melonis, Sphingomonas aquatilis, Brevibacillus centrosporus, and Gluconobacter oxydans were the most abundant microorganisms. Antioxidant activity of kombucha tested by ABTS and phosphomolybdenum method was 1.16 mg TEAC/ml and 2.04 mg TEAC/ml, respectively, which values were higher than in black tea 0.67 and 0.81 mg TEAC/ml, respectively. Also, content of total polyphenols (0.42 mg GAE/ ml), flavonoids (0.13 mg QE/ml), and phenolic acids (0.19 mg CAE/ml) was higher in kombucha than in black tea (0.18 mg GAE/ml; 0.02 mg QE/ml; 0.05 mg CAE/ml, respectively). Gallic, chlorogenic, syringic, and protocatechuic acids, and rutin and vitexin from flavonoids were dominant in kombucha beverage detected by HPLC. Strong difference in caffeine contents, 217.81 µg ml−1 (black tea) and 100.72 µg ml−1 (kombucha beverage), was observed. The amounts of theobromine were similar in black tea and kombucha, but theophylline was detected only in black tea in trace amount (0.52 µg ml−1).

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Microscopic organisms play a vital role in the field of green technology. Among the genera fungi, the group of entomopathogens includes Beauveria bassiana, which has been found to have multifunctional applications. In this present research, we have attempted to partially purify chitinase from two strains of Beauveria bassiana (F881 and F911), each cultured in minimal media with 1% (w/v) colloidal chitin as well as in Sabouraud's dextrose media with 1% (w/v) colloidal chitin. The purification process was done with a setup of ceramic membranes, which comprises two stages, ultrafiltration (50 nm pore size membrane) and nanofiltration (MWCO 5 kDa). Furthermore, with the analysis of yield of enzymatically hydrolyzed NAG (N-acetyl glucosamine), resistance and fouling of the membrane were also studied.

Open access

The aim of the present study was to investigate the biological activities of Tunisian olive leaf extracts and to correlate these activities to their phytochemical composition. The phenolic profile of four Tunisian autochthonous cultivars Chemlali, Sayali, Neb jmel, and Meski was determined using LC/MS-MS. The antioxidant activity of olive leaf extracts was evaluated using DPPH test. The antiproliferative effect was also investigated using MTT assay. The phytochemical screening showed that phenolic content and phenolic class repartition were significantly affected by olive leaf cultivars. Twenty-one components were identified and oleurpein, luteolin 4-glucoside, luteolin 7-glucoside, and apigenin 7-glucoside were the major phenolic components. Among all extracts, Sayali exhibited the strongest antioxidant and antiproliferative activities (IC50 41.36 µg ml−1 / EC50 147.11 µg ml−1). The MTT result showed that olive leaf extract reduced MCF-7 cell viability in a dose-dependent manner. Western blot analysis demonstrated that olive leaf extracts exhibited antiproliferative activity through apoptosis induction.

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Wheat gluten is mainly responsible for the structural characteristics of bakery products. When studying wheat proteins, it is important to use reliable extraction methods. Four different methods of wheat protein extraction were studied, with emphasis on the glutenin-rich fractions. The final quality of the protein fractions was evaluated in terms of denaturation, indirect yield, molecular weight, secondary structure, and thermal profile. Our results indicate that addition of dithiothreitol improves glutenin extraction without interfering with protein secondary structure and denaturation. Different thermal profiles were evidenced for different extraction methods, indicating the selectivity of the processes. Denaturation temperatures of the samples showed differences within about 3 °C, while denaturation enthalpies (ΔH) differed by about 14 kJ µg−1. Data in this paper may provide a broader perspective on how wheat proteins are affected by the extraction method.

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Garlic is widely used as food flavouring, and China is the world's largest garlic producer and exporter. To develop a convenient technique for evaluation of garlic cultivars would be worthwhile, and it would have wide application in such a huge market. In this research, 3D front-face fluorescence data of 8 garlic cultivars were recorded, and independent component analysis was used to decompose the overall fluorescence spectra into six independent components. The first, second, and fourth independent components showed a big difference among the cultivars, and the chemical fluorophores behind these three components were specified as protein, vitamin B6, and ATP, respectively, as fluorescent markers for evaluation. The result showed that all 8 cultivars cluster separately. The cultivar “YNQJ” have the highest quality in terms of protein and vitamin B6, “NXYC” and “SDHB” have the highest content of ATP, while “SXXA” is the poorest in terms of protein and ATP, and “HNJZ” has the lowest content of vitamin B6. Therefore, rapid evaluation of garlic cultivars can be accomplished successfully by using only the proportion values of three properly selected fluorescent markers.

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Authors: I. Cioffi, L. Santarpia, A. Vaccaro, M. Naccarato, R. Iacone, M. Marra, F. Contaldo and F. Pasanisi

The interest in gluten-free (GF) diet has greatly increased also in people without celiac disease (CD). This pilot study aimed to investigate the postprandial effect of GF-pasta, made by using the pasta-making process applied to artisan wheat pasta, on palatability, appetite sensation, and glucose metabolism in 8 healthy volunteers. Two iso-caloric lunch-meals consisting of: 1) gluten-free pasta (GFP) and 2) refined wheat pasta (RP) were compared in cross-over design. Both subjective appetite, assessed by visual analogue scale (VAS), and blood sample were taken before meal and at half-hour intervals for 4 hours. Palatability was evaluated immediately after the meal-test by VAS. All participants underwent pre- and postprandial energy expenditure (EE) measured by indirect calorimetry. We found that subjective palatability did not significantly differ between meals. Similarly, repeated measures ANOVA showed that GFP did not affect appetite ratings, postprandial glucose, and insulin responses compared to RP. Then, postprandial EE was affected by time (P=0.006), increasing at 60 min, but not by meals. In conclusion, artisanal GFP was as palatable as RP pasta, without affecting perceived satiety and postprandial glycaemia compared to RP in healthy subjects. Clearly, GFP results are preliminary and need to be investigated in larger studies.

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Authors: A. Blázovics, H. Fébel, G. Bekő, D. Kleiner, K. Szentmihályi and É. Sárdi

The effect of polyphenolic bioactive substances, especially resveratrol (12.03 mg l−1), of an often consumed Hungarian red wine was investigated in a short term rat experiment. Male young Wistar albino rats were treated with high volumes of red wine (matching one bottle of wine/day for a 85 kg man) (N=5) and another alcoholic drink of the same alcohol concentration (N=5), corresponding to the circumstances of alcoholism, and 5 rats were in the control group. A total of 7 routine laboratory parameters were measured from the sera by kits.

The changes of redox homeostasis (H-donor activity, induced chemiluminescence, diene-conjugates, GSHPx) were studied in blood plasma and/or in liver homogenates by spectrophotometric and luminometric methods. Transmethylation property of the liver was measured by overpressured layer chromatography (OPLC) technique. It was proven with in vitro OPLC analytical study that resveratrol reacted with methyl groups, and resveratrol was demonstrated to influence transmethylation processes as well as redox homeostasis. Red wine compounds do not protect from the harmful effects of alcohol, and even by high doses of resveratrol, the liver further deteriorates and the negative effect of alcohol increases. It has been confirmed that high doses of resveratrol do not provide protection against liver damage in those suffering from alcoholism.

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Abstract

Experimental investigations of laminated timber-concrete and steel-timber-concrete composite floor or bridge beams show that complex failure modes develop in such members. This paper presents acoustic emission investigation results that reveal the development of the failure modes in the steel-timber-concrete composite specimens subjected to short-term static ramp-loading. Accelerometers connected to a four channel dynamic signal analyzer continuously monitored the beam specimens during the load tests. Conventional techniques can be used for time domain data acquisition and evaluation of acoustic emission events generated in the structural member investigated, which contain thousands of independent signals to be processed, even if only in the audible frequency range. While the wavelet series of detected acoustic emission signals in the time domain produce a reliable amount of statistical information about the number and intensity of events, a frequency - time domain visualization may facilitate an advanced interpretation on the basis of spectrogram analysis. With on-site collection of data the methodology could allow for structural monitoring.

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Abstract

In this research, buckling behavior of rectangular plates of symmetric and antisymmetric laminated composite having centered circular hole under in-plane static loadings is analyzed with the aid of first shear deformation theory and the finite element method is used to find critical loads. The presence of hole may cause redistribution of stresses in plates with reduction of stability. The aim of the current paper is to find critical buckling load. The loads depend on many parameters like geometric aspect ratios (a/b) and (d/b), plate thickness (t), diameter of the circular hole (d), orientation of ply and boundary conditions. Numerical simulations for various boundary conditions obtained are shown in tables and graphical forms and compared with each other.

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Abstract

The analysis of track based inertial measurements for common crossing fault detection and prediction is presented in the paper. The measurement of spatial acceleration in common crossing spike and impact position during overall lifecycle are studied regarding to rolling surface fatigue degradation. Two approaches for retrieving the relation of inertial parameters to common crossing lifetime are proposed. The first one is based on the statistical learning method - t-SNE algorithm that helps to find out similarities in measured dataset. The second one is a mechanical approach that handles the data with a fatigue and contact models. Both approaches allow the significant improvement of the common crossing fault detection as well as its early prediction.

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Abstract

The yurt is one of the ancient living units for the nomadic cultural country. The yurt is a nomadic vernacular architecture, which has been developed for 3000 years. There are 31 counties using the yurt, out of which 13 of them use their traditional yurt around the world. Basically, the yurt was used as residential housings and today, also to some extent, for commercial and touristic purposes under different climates. Analyzing existing literature, as well as scientific publications it is apparent that besides architectural and structural topics, there is no existing investigation or published paper about building physics analysis of these buildings. Current research aims to create a database about energy and climate comfort qualities of traditional yurts using dynamic calculation tools. As a result, to intend to learn from the traditional yurt technology and to develop a completely new and modern building prototype based on the yurt-experiments in next step of research. Firstly, finding optimal solutions for a contemporary yurt-building' should be applied under Mongolian climate conditions, since this form of housing is still used in this country, and, in addition, the comfort and energy performance of the yurts were surprisingly satisfactory under extreme weather conditions, by temperature differences between summer and winter of approx. 80 K.

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Abstract

In Poland problem related to lack of rolling stock occurred recently. This article presents a comparison between two forecasting methods of realized transport work and transported freight mass by railway. The obtained results are also compared on a monthly and quarterly data basis. Knowing the exact values of forecasts railway carriers can plan the number of rolling stock. The calculations show that using the data as a monthly basis, the most reliable results can be obtained using the Holt model, while calculating data for quarterly basis results is closer to the real values using the Winters model.

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Abstract

The use of formal modeling has seen an increasing interest in the development of safety-critical, embedded microcomputer-controlled railway interlocking systems, due to its ability to specify the behavior of the systems using mathematically precise rules. The research goal is to prepare a specification-verification environment, which supports the developer of the railway interlocking systems in the creation of a formally-proven correct design and at the same time hides the inherent mathematical-computer since related background knowledge. The case study is presented with the aim to summarize the process of formalizing a domain specification, and to show further application possibilities (e.g. verification methods).

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Abstract

The aim of the research was to explore the proposed solar installation, which consisting of a solar wall, storage tank, radiation sources and measuring equipment. The solar installation was tested in a circulating mode, which is an important point in energy conservation. Planning the installation of the collector heating system is still at the stage of building the house. Therefore, it remains relevant to replace the traditional boiler on the solar wall in quality of the solar collector, which will be used to heat water in the system and/or the pool completely free of charge. Proposed construction of the solar wall is effective for the solar heat supply system, at the same time the results of research confirm not only the efficiency of the system, but also allow for the design stage to take into account the practical efficiency of the system. Solar wall in circulation mode has a sufficiently effective coefficient for combined hot water supply or preheating of the heating medium of the heating system. The main theses of this work also would like to mark the affordability for the consumer, since the following design does not require a separate installation, and has the ability to mount in the existing wall.

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Authors: Réka Csicsaiová, Štefan Stanko, Ivana Marko and Jaroslav Hrudka

Abstract

The article is aimed at finding out the behavior of the combined sewer network in the event of the occurrence of extreme precipitation events, which are associated with changes in the rainfall - runoff process in the urbanized area. Given the current situation of increased surface runoff in the urbanized area, it is necessary to extend the use of objects to reduce rainfall to the sewerage network. Part of the case-study was the design of percolation facilities in town Vráble, which are among the most used and most effective reduction measures. After designing the infiltration equipment and reducing the amount of rainwater discharged into the single sewerage network, the assessment of the sewerage network is satisfactory throughout the whole territory.

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Authors: Tim Chen, Aeyed Mohammad Hashemii, Rehaap Abd Elfatah Nussir, Ghanshyama Patankaw and John C. Y. Chen

Abstract

Environmental sandy construction is seeking about innovation, uniqueness substantive, symmetrical and congeniality with the scene. It applies zero-time substances (earth, water, air, and fire) in addition to the advantage of modernized technologies (smart and digital architecture) and re-revives the old models of conventional architectural techniques (contracts, domes). In order to find unorthodox solutions to interior configuration problems especially after physical disasters, the study highlights that it is remarkably critical to developing new intelligent solutions and atypical to the quandaries and requirements of interior design furniture by the concept of phenomenology, place, environment, and architecture.

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Abstract

In this study, non-linear behavior of steel frames with dual lateral loader system with convergent crossing and chevron bracing equipped with linear and non-linear liquid viscose dampers in 8 and 12 story models as 2D under the record of near and far field to fault earthquakes are studied, evaluated and compared. For doing time history non-linear analyses, non-linear analysis software of Perform-3D has been used. This research absolutely confirms that viscose dampers reduces structure's responses under the effect of near and far field to fault records in a way that using non-linear viscose dampers in dual steel frames, the rate of created reduction is under the effect of near field records and more.

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Abstract

This paper summarizes the authors' up-to-date results in the research topic of railway ballast particles' breakage test with individual laboratory test. In the past few years there were a lot of railway rehabilitation and maintenance project in Hungary, as well as abroad. The largest part of world's railways has traditional superstructure, i.e. they are so called ballasted tracks. The railway ballast is the highest mass in the railways' superstructure. Nowadays, it is a naturally fact that there is enough quantity of railway ballast in adequate quality. However, due to the modifications and restrictions in the related regulations since 2010, there are only few quarries in Hungary, which are able to ensure adequate railway ballast material for railway construction and maintenance projects for speed values between 120 and 160 km/h. Quarrying industry is stricken by aggravated environmental, heritage and conservation regulations year by year, it limits the accessibility of mineral wealth in significant manner. This fact with quality requirements means supply and quality risk in production of railway ballast in medium term. The main goal of authors' research is to be able to simulate the stress-strain effect of ballast particles in real and objective manner in laboratory circumstances, as well as in discrete element method modeling. This paper introduces the exact assembly of executed laboratory test and newest test results. The authors summarize the up-to-date international literature review, using that they give short outlook to the planned research with research directions in near future.

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Abstract

Modernization tendencies in architecture and street infrastructure were introduced in Kosovo during the Tanzimat Reforms, enforced by the Ottoman Empire in the late 19th century. Lack of original archive documentation until now has impeded scientific approach to urban and architectural analysis, for which reason, Kosovo cities often face difficulties in documenting their historical and cultural continuity. In order to fill the gap of knowledge about urban built heritage of 19th century in Kosovo, this paper uses and analyzes original visual archival documents, retrieved by author from the Premiership Ottoman Archives Analyses show that construction of street network and public buildings was realized in line with the needs arising from new administrative division imposed by the Tanzimat Reforms. While street network intended to connect Kosovo settlements, public buildings and especially the government buildings built in Prizren and Prishtina, former centers of Vilayets, intended to introduce new building standards and a new language of architecture. Interrogation of modernization tendencies in architecture and street network in Kosovo during this period is important for establishing a continuity of future planning development, as well as in narrating modernization tendencies that occurred in Kosovo in line with other parts of the Late Ottoman Empire territories in the Balkan.

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Authors: Zoltan Vizvari, Tibor Kiss, Csaba Ver, Kalman Mathe, Bojan Kuljic, Ferenc Henezi and Peter Odry

Abstract

The presented multichannel measuring system working on various frequencies is suitable either for electrical impedance spectroscopy or tomography. The authors of this paper have developed the complete measurement system and a graphical user interface platform. The accuracy of impedance amplitude and phase are 1 ppm and 0.01°, respectively. The basic instrument works with 8 channels and can be expanded to 64 channels with the application of multiplexing or multiple parallel connected instruments in the same system.

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Authors: Bálint G. Halász, Bálint Németh and István Kiss

Abstract

The purpose of this paper is to show a new calculation model, which is able to calculate the incident energy in any places near an electric arc in case of high voltage, without neglecting of length and position of the electric arc. This method is developed especially for the electric transmission network above 35 kV and several meters of gap distances. It would be used to estimate the thermal load of a power line worker close an initiated electric arc during live-line maintenance by bare-hand and hot stick method as well.

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Abstract

Numerical research in the context of urban in a humid continental climate zone is still limited. The aim of modeling the case study is to assess the performance of outdoor thermal comfort parameters and investigate their capabilities in achieving the outdoor thermal comfort. A computer-based tool is used to quantitatively study the outdoor thermal comfort and its weather parameters. The parameters have been analyzed using ENVI-met tool and then compared against different comfort scales like relative humidity comfort scale, the predicted mean vote scale as well as other scales and standards. The results have shown that the average predicted mean vote value is +4 (very hot), the average air temperature is hot, the average wind speed is light breeze and the relative humidity falls within the comfort range. However, street orientation, shading, water bodies and plantation play a significant role in increasing and decreasing the outdoor thermal comfort.

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Authors: Youssef Regad, Bachir Elkihel, Farid Boushaba and Mimoun Chourak

Abstract

The main goal of this study is firstly to model the phenomenon of advection and diffusion of the gaseous residues of coal combustion. On the other hand, to study the dispersion of this pollution by varying the parameters like the wind and the resources of pollution, where there are four emissions: SO2, CO, NO2 and PM10. The present model will compare estimating concentrations with the results found by the contribution of the thermal power plant of Jerada city, where the American Environmental Regulatory Model is used. The results suggest that SO2, PM10, NO2 and CO concentration simulated by turbulent k-ε model in combination with the transport model of diluted species, at the 3h and 24h intervals, greater than their respective observed concentrations compared with the American Environmental Regulatory Model. The concentrations of the model found are very high and exceed the limit values under the study conditions. Indeed, the simulated model was used in 2D with a very low wind speed (10−4 m/s) and in the absence of gravity, hence the total neglect of altitude because the two sources of pollution are at the height of 120 m.

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