Discover the Latest Journals in Architecture and Architectonics

Architecture is both the process and product of planning, designing, and constructing a building or structure, while architectonics is the scientific study of architecture itself. Architectural works are often considered important cultural symbols and works of art, and we often identify past civilizations with their architectural heritage.

Architecture and Architectonics

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Abstract

Accessibility is known as the ease of reaching destinations. The accessibility is determined by the spatial distribution of potential destinations, and the magnitude, quality, and character of the activities found there. However, modernization and the fast expansion of urban development transform cities' local cultural life from walkable accessible places to just car places. This has encroached into every corner of our urban environment today. In addition, the available services and systems to manage the pedestrian movement in the historic core are inadequate and inefficient, posing risks to both the traffic and the pedestrians. That affects the walkability for cities gradually. Hence, this paper aims to explore the main physical elements that contribute toward accessibility under three main categories (pedestrians, vehicles and public transport) as one of the walkability characters in Salt City in Jordan. Historical review, site analysis, and survey were the main methodology used in this study.

Open access

Abstract

Cracking in composite steel-concrete bridge decks is a common problem in civil engineering. Before, or shortly after, the bridge is subjected to live loads; various levels of cracking can appear, mostly due to plastic shrinkage and temperature effects.

This paper presents an investigation of the behavior of cracked concrete in a composite deck slab of a railway bridge supported by steel girders using the finite element method. Eurocode 4-2 proposes a few simplified methods for calculating shrinkage and cracking effects in concrete. Through the proposed methods of analysis, an analytical simulation of a continuous composite steel-concrete bridge deck is performed and some practical recommendations for analyzing beam girders of this type are given.

Open access

Abstract

The focus of this study is how Xiazhuang Village with high quality resources can achieve sustainable development in the new era by protecting and transforming vernacular architecture. Based on the layout of village, the characteristics of vernacular architecture and the ecological advantages of construction technology, this study puts forward the classification renewal and optimization design based on different buildings to solve the problems of village. Try to find a way to continue the historical context of vernacular architecture and satisfy the development of rural tourism at the same time.

Open access

Abstract

The urban structure of Dombóvár has been transformed in recent centuries, and the protected buildings that once defined the town center, have been relegated to the periphery. Today, despite its rich architectural heritage, the Kakasdomb district is an area at risk of segregation. The key to the integration of the district into the existing urban tissue is the utilization of the protected buildings of the area including the former synagogue building. This paper examines the possibilities for the reuse of the synagogue based on the town development strategy and the perceptions of the remaining Jewish community, and the systematic modification of the settlement structure, together with the possibilities for the integration of the neighborhood.

Open access

Abstract

For the final quality of the part, metal forming trends are depending on improvements of friction and tribology. As a consequence, there is a trend in which tribology and friction are becoming increasingly important for correctly replicating the forming simulation of those parts. The objective of this work was to improve the forming simulation of an automotive shell part on AutoForm. The part was provided by a vehicle industry supplier. Enhanced Coulomb models consider a change on friction coefficient due to different factors, better approximating the description of friction to reality. For the current study, pressure and velocity dependent friction models were chosen as long as the combination of both. The virtual tribology was simulated using the software TriboForm. Velocity dependent friction model and the virtual tribology have shown similar results with expected lower coefficients of friction.

Open access

Abstract

Vehicle manufacturing is an industry in which the technologies used by Industry 4.0 and their evolution can best be traced. Digitalization-robotization is paramount to the technical methods used in the Fourth Industrial Revolution. The question is how close a correlation between productivity and digitalization robotics in vehicle production is in the Member States of the European Union. I perform the relationship between the two variables by correlation calculation. Then I classify the member states according to the closeness of the relationship between the two variables using the method of hierarchical cluster analysis. Empirical results show a robust relationship, with the highest per capita production value in those Member States with the highest degree of digitalization-robotization in vehicle production. In conclusion, the countries in Central and Eastern Europe and the end of the productivity rankings need to increase the degree of digitalization of their vehicle production to increase their productivity and competitiveness.

Open access

Abstract

With the gradual improvement of urban construction, more and more experts and the public realized that the speed of urban development be reasonable, which caused urban regeneration to turn to a new-minded “urban micro-regeneration”. “Micro-regeneration” is an extension of the concept to the direction of urban construction. The concept of micro-regeneration was first applied to the regeneration of individual buildings in the old city. The research on the intervention of public art in urban micro-regeneration is still in its infancy in China. Based on practice, this paper explores the possibility of public art's intervention in urban micro-regeneration.

Open access

Evolution and Cyclicality in Rural Tourism •

Experience of Tourism Development in the Inner-Őrség in the Light of Statistical Data

Fejlődés és ciklikusság a vidéki turizmusban •

A Belső-Őrség turizmusfejlődésének tapasztalatai a statisztikai adatok tükrében
Építés - Építészettudomány
Authors: Ágnes Bertyák and Kornélia Kissfazekas

Tourism is one of the fastest-growing economic sectors in the world, and any settlement that can harness and promote its potential can benefit from it. It is not only the prerogative of cities but can also make a significant contribution to the survival and development of smaller settlements.

The development of tourism in a given area is not a sudden, rapid process, but usually takes place over several decades, through cyclical phases. Our research is based on the different hypothetical models of the stages of tourism developed by Noronha (1977) and , the applicability of which was examined in rural areas through the example of the Inner-Őrség. Nowadays Őrség (Guard’s Country) is one of the most popular tourist destinations in Hungary, where the small settlements of the area have built on their natural, architectural and cultural assets and they have been able to exploit their potential by using the right marketing techniques. The villages of the Inner-Őrség have developed at different rates since their discovery as tourist destinations, and depending on their role in the settlement network, their accessibility and tourist values, the different phases of tourism development took place at different speeds in their territory. Therefore, the intensity and impact of tourism varies in each village despite the strong interaction between them.

In the present study, we seek to identify the trends and characteristics of the development of tourism in the examined area by using the results of the available statistical data, in order to obtain a more accurate picture of the role of tourism in the settlements concerned.

Open access

Abstract

Identification of online hate is the prime concern for natural language processing researchers; social media has augmented this menace by providing a virtual platform for online harassment. This study identifies online harassment using the trolling aggression and cyber-bullying dataset from shared tasks workshop. This work concentrates on extreme pre-processing and ensemble approach for model building; this study also considers the existing algorithms like the random forest, logistic regression, multinomial Naïve Bayes. Logistic regression proves to be more efficient with the highest accuracy of 57.91%. Ensemble bidirectional encoder representation from transformers showed promising results with 62% precision, which is better than most existing models.

Open access

Abstract

Timber is a widely used material in construction. The moisture content has a significant impact on the mechanical and physical properties of it. This paper studies how the moisture content values are directly connected to the climate conditions, especially temperature and relative humidity, by measuring these factors for a non-renovated historical timber roof for a one-year period, combined with meteorological data for Pécs since 1901. The fluctuation in moisture content values created instability in the water content of the structural elements due to absorption and release of water in order to reach the equivalent moisture content point. This process led to continuous volume increase-decrease of the timber, thus to formation of cracks, discoloration and harmful fungi development.

Open access

Abstract

The comparison of Mono and Multi Repository structures is a highly debated topic in the software development field. Despite the choice of repository structure is the first main step in development; so far, this comparison has only been made on a small or local scale. Here, Mono and Multi Repository structures have been compared from different aspects using thousands of projects.

First, an algorithm shared for collecting and identifying Mono and Multi Repository projects and save them into the database. Database was used for making different comparisons for example the usage intensity of both structure types over time, the developer's preference over structure type based on their country and so on. Also, all these comparisons have been made according to the team size and development period for each repository structure.

Open access

Abstract

Two different tire configurations consisting of a dual tire and a super single wide tire having different range and distribution of contact pressures have been analyzed. Along with the effect of speed on development of pavement damage at speeds of 5, 50 and 80 km h−1 under zero and uniform wander modes. Results show that at super slow speeds of 5 km h−1, at dual wheel moving at zero wander mode, decrease in fatigue life of the pavement is 3.5 years, which is 1.45 times more than the dual wheel moving at uniform wander and 3.4 times more than wide tire moving at uniform wander mode. The difference between fatigue damage at different lateral wander modes is prominent at speeds greater than 50 km h−1. A wide tire performs better than the dual wheel under zero wander configurations.

Open access

Elmélet és gyakorlat kapcsolata •

Műegyetemi építészkari tervezési munkák az 1950-es évekből

The Relationship Between Theory and Practice •

Design Works of the Faculty of Architecture at the Budapest Technical University in the 1950s
Építés - Építészettudomány
Authors: Rita Karácsony and Zorán Vukoszávlyev

The article examines the relationship between theory and practice through the history of architecture education, considering the possibilities of the 1950s from the perspective of teachers and students. This period may be the subject of separate research for two reasons. On the one hand, at the turn of the 1940s and 1950s, private offices were replaced by large state owned design institutes, and so professors could no longer pursue independent design activities in addition to education, although not long ago the two were even more physically intertwined as they could operate their offices within the university departments. The other that may have attracted interest in the early 1950s is the emergence of the socialist realist style dictatorship, to which education also had to adapt. The importance of practical experience for design instructors was recognized from all directions, so a solution was soon found: as a working community of design departments in the faculty of architecture they were invited to apply for large-scale design competitions or they were contacted directly. The study lists the departmental works published in the journal Magyar Építőművészet recently and presents the current architectural tendencies through them, which also had a clear effect on the education at the Technical University. In the following topic we deal with the possibilities of the students, since in the education system of architecture, in addition to the acquisition of theoretical knowledge, the widest possible expansion of practical knowledge has been of great importance – both in the past and today. Students could also take part in certain departmental tasks, or in design competitions, working with a special permit, and all of them were obliged to participate in the summer practical construction camps from 1951 onwards. With the help of personal recalls, we also look at how satisfied the teachers and students were with their tasks outside the university – so the archival and literature sources are supplemented with personal points of view.

Open access

Abstract

The design of supported embankments on soft soil is a common challenge for civil engineers. This article aims to evaluate the performance of three advanced constitutive models for predicting the behavior of soft soils, i.e., hardening soil, hardening soil model with small-strain stiffness, and soft soil creep. A case study of a rigid inclusion-supported embankment is used for this purpose. Plaxis 3D program was adopted to predict the settlements in subsoil layers and vertical stresses in the load transfer platform. Comparison between field measurements and result of Plaxis 3D modeling was performed. Results demonstrate that soft soil creep model yields predictions in a good agreement with the field measurements, while hardening soil small strain model gives slightly worst predictions.

Open access

Abstract

Wind generation is regarded by many as the future of renewable energy source, but the difficulty of recycling end-of-life wind turbine components could create another kind of environmental pollution. Either landfill or incineration of end-of-life wind turbine components will cause environmental hazards. However, the current recycling technology is immature and economical. Make clean energy ‘cleaner’! The recycling of end-of-life wind turbine rotor hub and blades has become a new goal and task for architects and designers. This article uses a real project reconstructed by end-of-life wind turbine components to demonstrate the positive role of spatial narrative in achieving low-carbon and sustainable design.

Open access

Abstract

The floodplains of the Tisza River, stretching across the eastern part of Hungary, are often affected by riverine and inland excess water flooding and draught. This paper investigates a possible solution to this problem utilizing the water retention capabilities of old floodplains. In this study, the effect of the position of the inlet structures of a floodplain, near Csongrád town, was examined with HEC-RAS 1D-2D coupled model. Based on the results, the rules of the deep floodplain selection were determined. On the extended model, the possibilities of a deep floodplain storage area chain have been explored. According to the estimate, more than 2.36 km3 potential storage capacity is available along the Hungarian section of the Tisza River.

Open access

Abstract

In order to develop and enhance the quality of life in Tunisian urban spaces, the integration of street furniture became a new challenge for urban designers to use new methods and techniques to combine functionality and aesthetics into their design. The main objective of this paper is to focus on the analysis of the street furniture user’s needs in urban spaces to understand and discuss the requirements that should be considered while designing.

Open access

Abstract

Nature-based solutions use a holistic viewpoint to address social challenges while providing environmental, social and economic benefits simultaneously. The Victoria Quay is a historical space with complex social and environmental issues. This study uses an investigation-oriented method to explore the re-planning strategies. The environmental problems are addressed by extending the green infrastructure into the site to recover the ecological corridor and alleviate flooding risks. The originally single land-use type is changed, and several historical buildings are transformed into landmarks to improve the connection with city center by linking the ‘golden route’. All the proposed measures tried to reactivate the various relationships rather than merely renew the Victoria Quay.

Open access

Abstract

Based on the theory of space syntax, this research conducts a quantitative study on the four stages of Zhanjiang urban spatial organization system, and draws the urban evolution process. This study found that the development strategy of different periods has a huge impact on the urban development. It determines the structural basis of the original urban space and creates strong development inertia. According to these research results, it can provide an effective theoretical reference for the future spatial expansion of the city.

Open access

Abstract

With the rapid development of China’s urbanization, a large number of people have moved from rural to urban areas. People have proposed higher and more urgent needs for the urban environment. Particularly, the urban street landscape is close to people’s lives, and the upgrading of design methods can improve the quality of life. Besides, the application of artificial intelligence design has become possible as information technology develops. In this paper, a visual simulator is established through algorithm models and applied to street landscape design.

Open access
Pollack Periodica
Authors: Mohammad Alzghoul, Sebastian Cabezas, and Attila Szilágyi

Abstract

The aim is to derive an expression to calculate the natural frequencies and plot the mode shapes of a simply-supported beam with an overhang with an end overhang point mass by using the Euler-Bernoulli theory in the case of free transverse vibrations. The results are validated by finite element analysis. The importance of the system presented is that it can represent machine tool spindles or even machining tools like boring bars. The results are in good agreement with the results from the finite element analyses. The derived expression can be used in optimizing the value of the point mass and optimizing the support location for better performance of the system without the need to perform complex analysis to obtain the values of the natural frequencies and to plot the mode shapes.

Open access

Abstract

In this research work existing laboratory tests of slim floor beams with solid monolithic concrete slab were modeled and analyzed using GID and Atena software. After validating the advanced finite element model with the test results of the international literature, structural parameters were analyzed with the aim to study their influence on the load bearing and deformation capacity of the beams. The parameters were related to the geometric of the beam: size of web openings and top concrete cover. With these results conclusion can be noticed that focusing on the optimal arrangement of the geometrical parameters of the composite beam could lead to better structural behavior with more economical solutions.

Open access

Abstract

The optimization of high-rise office buildings' envelope and the application of energy-efficient measures have become a priority nowadays. Therefore, this investigation aims to assess the role of the façade's geometry design factors, e.g., folded façade perforation, window orientation, and window-to-wall ratio on building comfort and energy performance. The energy simulations were performed using IDA ICE 4.8 thermal simulation program to evaluate the thermal and visual comfort and the energy consumption of various façade test models. The optimization resulted in a façade model with a great level of thermal and visual comfort as well as a total energy reduction of 14%, representing a good compromise solution in the trade-off between thermal and visual comfort as well as energy efficiency.

Open access
Pollack Periodica
Authors: Patrik Márk Máder, Olivér Rák, Nándor Bakai, József Etlinger, and Márk Zagorácz

Abstract

Nowadays, it is increasingly important to develop economical construction processes and determine predictable costs. The current level of technology offers countless, even undeveloped opportunities to support architectural, engineering, and construction processes. Building information models created as results of design processes and databases associated with them can provide an appropriate base to fulfill the requirements. However, this information is mainly available only for the largest projects; the possibilities offered by traditional editable vector files (e.g., *.DWG) should also be examined. This study analyzes the efficiency increasing possibilities that can be achieved using low-detail 3D models generated by algorithms and applying 2D-based digital quantity estimation workflows.

Open access

Abstract

Frame structures are defined as structures built of straight, less often curved bars, which are dimensioned to carry a planar or spatial load. These frames are generally considered statically indeterminate structures so that several methods can be used to determine their loads, but all of them require some simplification. This paper is not concerned with investigating these theories for determining the stresses but with the optimum design of a frame structure for a given geometry. Several different loads have been considered, where the value of the wind load in the horizontal direction has been considered. The optimization problem is mathematically formulated so that both compressive forces and bending moments acting on the horizontal beam and the vertical column, and their composite loads, are below the limit set by the material properties. The column connections were assumed to be fully rigid, and welded I-section were considered for both columns. For local bending conditions, the Eurocode 3 specification was applied. Several steel grades were tested during the investigations, and fire loading was considered an additional load. In this case, a higher safety factor was assumed to make the times to collapse comparable.

Open access
Pollack Periodica
Authors: Hui Cao, Anna Mária Tamás, Gergely Sztranyák, and Erqing Zhang

Abstract

Vernacular architecture is the source of the historical development of architecture and the carrier of traditional culture. It is also the emotional sustenance of contemporary Chinese people’s beautiful homesickness. With the rapid expansion of urbanization in China, a widespread phenomenon of “hollow villages” has emerged in rural areas, and there are many abandoned rural buildings all over the countryside. Therefore, the protection and sustainable development of rural architecture are imminent. Based on the author’s rural construction project in China, this research integrates environmental psychology and architecture and tries to build a high-quality living environment, aiming to explore a new design strategy to meet the challenges in the future.

Open access

Abstract

Because of thin wall thicknesses and closed bottom ends of the extruded aerosol can, the necking limit analysis needs intensive investigation. The numerical analysis of the necking process of 0.45 mm thickness pure aluminum aerosol can was carried out. The result indicated that the length of the aerosol can wall, which is not fixed by the bottom die and the angle of inclination of necking tools are important factors that affect the development of deformation boundary limits due to plastic instability of local buckling. The fraction of taper angle of tool becomes more series parameter while necking at larger free length and it needs more concentration. Instead, the ratio of necking tool displacement to the total free length to initiate buckling was increased while increasing free length.

Open access

Abstract

China has a lengthy and glorious history spanning thousands of years. Traditional dwellings represent distinct regional cultural origins, and different forms of housing constructions have arisen as a result. However, traditional dwellings preserve area culture and specific life memories as a fundamental component of rural life. From the perspective of conventional dwellings, this paper takes the representative Manchu folk houses in Northeast China as an example. It discusses the architectural structure, appearance style, and overall style of Manchu folk dwellings and the cultural dimension of architecture and its distinctive value under the impact of regional culture.

Open access

Abstract

Building Information Modelling (BIM) involves management efforts, tools and applications for enhancing information flow and, therefore, productivity of projects; adoption of BIM and the increasing use of digital technologies (e.g. data centers) in construction and operation of buildings, as well as in maintenance can transform the way how the industry works. Telecommunication cabinets equipped with large number of components of different types are inevitable parts of data centers having a significant influence on the efficiency and the reliability of data centers. Since the layout of equipment inside telecommunication cabinets is crucial in data centers and the ideal location of equipment inside each cabinet can be unique, an algorithmic and automated process is necessary for the cabinet façade scheme design; manually created diagrams can lead to errors. Furthermore, precise and up-to-date pieces of information about the special layout of equipment in each cabinet are also important for the further operation and maintenance. As an answer to this challenge, a BIM-based approach and method are presented in this article that can result in significant cost savings. When designing data centers, special attention must be paid to the location of telecommunication cabinets, the design of cable routes, and the layout of equipment inside. The novel cabinet family for BIM technology-based method has been developed for the improvement of data center design. Cable trays plug-in can lead to higher quality and efficiency of construction and the facility management as well.

The main goal of the case study: optimization of the design process of structured cabling systems (SCS) in data centers (DC) using new additional BIM capabilities.

The novel dynamic cabinet family have several distinctive features:

  • the ability to select in the properties which equipment will be inside the cabinet and which unit will occupy;

  • possibility to change and add equipment inside the cabinet;

  • creation of cabinet façade scheme based on equipment inside the cabinet;

  • automatically created specification;

Cable tray plug-in can improve and automate the design process in the following areas:

  • place trays depending on the installation method (wall, floor, ceiling);

  • place elements of the trays (hangers, consoles, racks) in a user-defined interval;

  • place tray connectors based on selected connector type and tray type at user-selectable spacing;

  • adding a tray cover and a partition in the tray properties;

  • automatically created specification of all cable trays elements.

The model created in BIM can be used for further operation and maintenance. To reach it, each of the elements or groups of elements contains a unique number that allows to bind its parameters and geometry for further export and use in the production model.

Open access

Abstract

The aim of this study is the manufacturing analysis of five spur gear pairs where the initial geometric parameters are the same only the pressure angle is different. Firstly, the gears must be designed and modelled. After that, I analyse the modification of this geometric parameter for the manufacturing parameters of the pinion and the gear in the case of gear cutting by module disc milling cutter. Using this technology the one tooth cutting can repeat from tooth to tooth in the function of the number of teeth. I would like to find correlations between the pressure angle and the manufacturing parameters. For this purpose, I define the initial technological parameters and calculate necessary technological parameters for the manufacturing process in a general way. I also define the manufacturing parameters for the given gear geometries. This analysis is practical and theoretical at the same time since the results and the process can help the manufacturing engineers to develop the gear manufacturing processes and applying my results for similar manufacturing problems.

Open access

Abstract

The study presents a mathematical model for building heating control. The buildings are connected to district heating or to central heating. The task of the heating control is to maintain a preset constant indoor air temperature. Control disturbance is caused by external meteorological conditions, firstly by outdoor air temperature. The control action can be the change in heat transfer capacity of the radiators, whereby the indoor air temperature can be commanded back to the present value to offset the effect of the disturbance. Just the control can be a follower or of predictive type. The expected indoor air temperature can be calculated from the energy balances. These are composed of differential equations, describing dynamic equilibrium of heat transfer through the external walls, as well as heat storage in the walls and indoor air. Type of differential equations is linear, inhomogeneous, of first or second order.

Solution of the differential equation results in describing the change in indoor air temperature in time as a function of outdoor air temperature. Further on, the equation determines the function of the necessary heating capacity to keep the indoor air temperature constant. By the model several heating programs can be evaluated. The physical model is shown in Fig. 1. Intermediate variable is the average temperature of the external walls. Heat conduction and convection through the walls is calculated by the difference of the indoor air temperature and of the average wall temperature by using relevant R 1 and R 2 heat resistance factors. The model is adequate when the heat transport within the building sections is neglectable, and the thermodynamic and heat transfer characteristics of the walls are identical. Thereby the model describes the heat balance of representative premises, but the results can be transferred to similar other premises, too.

Open access

Abstract

This study focuses on the supply chain actors’ QCD framework. The authors present an innovative tool that illustrates the operating system of different actors in the supply chain by combining virtual and physical reality. The study aims to present and “visualize” the QCD coherence system with the help of the PaTeNt© – QCD spatial model. The study, therefore, focuses on the supplier, the central company; the relationship between the supply chain actors and the QCD framework, which is suitable for the agile, proactive collaboration.

The parts of the model, which is the result of the development:

  • the elements of quality,

  • the elements of cost,

  • the elements of delivery.

The development of the model was brought to life by the tasks which need to be solved and this model helps the understanding and transparency during the work.

Open access

Abstract

The biggest question of professional sports is how to compete successfully in the global economic framework, simultaneously in terms of the sport and in economic terms. As a result, in addition to indicators measuring sports-related effectiveness, the need for an economic analysis of sport has also emerged. Most academic research into the economic aspects of sports are related to the analysis of North American major league sports, as well as to European football. Water polo is also a spectator team sport, yet its economic analysis is almost entirely missing. In this article, we present an economic analysis of the operation of five men’s water polo teams – the top four teams in terms of the sports results and one from the mid-range – competing in the highest-level national championship in Hungary. Our aim is to determine, on the basis of the analysis of the data, the relationship between effectiveness in sports and the economic background of the teams.

It can undoubtedly be concluded that, in addition to appropriate professional decisions, it is the economic situation of a club that has a clear impact on their effectiveness; in other words, up to a certain point, the more disposable funds and wider range of assets a sports company has, the more effectively it can prepare and the better results it will have in the various domestic and international championships and tournaments. CIT (corporate income tax benefits, “TAO” in Hungarian) support is fundamentally important in the field of youth sports development. While professional sports in Hungary are built on the development of junior players, there is still no clear link between the successfulness of the adult and the junior teams. The first-division teams of the clubs providing the best junior players are frequently in the mid-range or occasionally among the weakest teams in the national championship.

Our research has shown that apart from the fact that some teams are extremely successful in the water polo championship, the outcome of many matches becomes quite predictable. Based on these, the uncertainty of the outcome is compromised, and the championship becomes less exciting and also loses some of its audience.

Open access

Abstract

High performance concrete is extensively used for construction works in recent era. For the preparation of high performance concrete (HPC) mineral and chemical admixtures are used. The addition of mineral admixtures minimizes the utilization of cement and makes concrete more sustainable. The addition of metakaolin as a substitute to cement enhances the properties of concrete. There is need to study the mechanical and micro-structural properties of concrete containing metakaolin as cementitious material. In this work an endeavour has been made to study the properties of HPC employing matakaolin as an alternative for cement. The cement has been replaced with metakaolin by 5%, 10%, 15%, 20%, and 25% respectively for 0.25, 0.3, and 0.35 w/c ratios. The strength and electrical resistivity tests are conducted for all concrete mixes on triplicate. Results confirm that the accumulation of metakaolin increases the properties of HPC. A maximum of 49% increase in compressive strength in concrete was observed by the accumulation of 15% of metakaolin in concrete as substitute to cement for 0.25 w/c ratio in comparison to standard concrete. The development of secondary calcium silicate hydrates and minimal Ca(OH)2 components was revealed by X-ray spectroscopy, indicating that the concrete was denser. The results of this study revealed that metakaolin has a considerable impact on high-performance concrete, particularly in terms of compressive and flexural strength.

Open access

Abstract

Shape memory alloys are smart materials which have remarkable properties that promoted their use in a large variety of innovative applications. In this work, the shape memory effect and superelastic behavior of nickel-titanium helical spring was studied based on the finite element method. The three-dimensional constitutive model proposed by Auricchio has been used through the built-in library of ANSYS® Workbench 2020 R2 to simulate the superelastic effect and one-way shape memory effect which are exhibited by nickel-titanium alloy. Considering the first effect, the associated force-displacement curves were calculated as function of displacement amplitude. The influence of changing isothermal body temperature on the loading-unloading hysteretic response was studied. Convergence of the numerical model was assessed by comparison with experimental data taken from the literature. For the second effect, force-displacement curves that are associated to a complete one-way thermomechanical cycle were evaluated for different configurations of helical springs. Explicit correlations that can be applied for the purpose of helical spring's design were derived.

Open access

Abstract

Composite materials are granted first choice in the present manufacturing scenario due to their compatibility with tolerances up to 0.001 mm and lower weight. The research design works on the composites of the metal matrix, which are used primarily for aeronautical and industrial applications. Metal matrix composites are being used extensively in structural engineering. Silicon carbide and fly shell ash were used as compliance in aluminium alloys for the manufacture of metal matrix composites (LM13). The composite metal matrix is created employing Stir Casting method. When compared to open moulding, closed moulding, and cast polymer moulding, it is a less expensive and more effective method. The composites produced were then examined for mechanical properties, from the results it was found that the presence of ash and ceramic grains can adversely impact the properties of the composites and even make them brittle. It is time to change the mechanical properties of aluminium by creating hybrid composites with double and often triple-reinforced sections. Hybrid composites have greater performance, better tolerance to tear, low density, resistance to corrosion and strong rigidity over metal matrix composites. In this research an Al-Sic-fly ash composite is proposed and the mechanical properties of hardness, tensile strength, corrosion strength, micro structure analysis are investigated.

Open access

Abstract

The aim of the thesis is the geometric design, CAD modelling and TCA of spur gear pairs having normal teeth based on the modification of the pressure angle. The first task is the geometric design and CAD modelling of the gear pairs (5 pairs are designed) where only the pressure angle is modified beside the constancy of the other initial parameters. The second task is to analyse the comparison possibility and the accuracy similarity of the 2D and the 3D models by the Hertz (equivalent) stress analysis. Finally, I give analysis of the maximum equivalent stress, normal stress and contact pressure for each pair while three teeth are rolling down on each other.

Open access

Understanding Centrality Theories •

Socio-spatial Characteristics and Interrelations of City Centers

Városközpont-elmélet•

A városközpontok, alközpontok téri és társadalmi jellemzői
Építés - Építészettudomány
Authors: Anna Kornélia Losonczy and Annamária Orbán

The study is based on the re-combination or synthesis of international scientific literature, and the definition of the notions center, and sub-center. A conceptual-structural framework of socio-spatial characteristics of centers (and sub-centers) is set up, these factors are essential elements of making, maintaining, and rehabilitating a city: Market and Competition; Node and Pole; Faith; Power; Security; Mixture; and Identity. In an evaluation matrix, the meta-physical characteristics (that are the determining factors of the physical attributes) of these archetypes are drawn. Based on famous theorists, three types of city forms are distinguished: the “traditional / organic”, the “modern / planned”, and the “contemporary / disjointed” ones. We argue that the historical, theoretical-conceptual background of the triple division is comprehensible. However, this trichotomy lacks some essential elements, “measurable” aspects of city centers – outlined in our study –, which are important in contemporary urban processes and support more realistic urban planning.

Tanulmányunkban – nemzetközi szakirodalmi kutatás alapján – definiáljuk a központ és az alközpont fogalmakat. Meghatározzuk a központok (és az alközpontok) téri-társadalmi jellemzőinek konceptuális és strukturális keretrendszerét. Ezek az alkotóelemek – Piac és Verseny; Csomópont és Pólus; Hit; Hatalom; Biztonság; Vegyesség; Identitás – a város alapításának, fenntartásának és megújításának feltételei. Egy értékelő mátrix segítségével összegezzük ezen archetípusok metafizikai jellemzőit, és amellett érvelünk, hogy ezek determinálják a központok fizikai tulajdonságait. Elismert szerzőkre hivatkozva ismertetjük a legelfogadottabb városmodellek hármas felosztását: a hagyományos / organikus, a modern / tervezett és a kortárs / széttagolt tipológiát. Azt állítjuk, hogy a hármas felosztás történelmi, elméleti-konceptuális háttere megalapozott. Ugyanakkor ez a hármasság nem foglalja magában azokat a „mérhető” – a tanulmányban felvázolt – szempontokat, amelyek segítségével a valósághoz jobban közelítő, a tervezési gyakorlatban könnyebben alkalmazható központmodellek vázolhatók fel.

Open access

Abstract

Laminated composite shell panels take part in several engineering structures. Due to their complex nature, failure modes in composites are highly dependent on the geometry, direction of loading and orientation of the fibers. However, the design of composite parts is still a delicate task because of these fiber failure modes, which includes matrix failure modes or other so-called interlaminar interface failure such as delamination, that corresponds to the separation of adjacent layers of the laminate as a consequence of the weakening of interface layer between them. In this work, impact-induced delamination represented as a circular single delamination is investigated, as it can reduce greatly the structural integrity without getting detected. Furthermore, attention is focused on its effect upon the post-buckling response and the compressive strength of a composite panel. The delamination buckling was modelled using the cohesive element technique under Abaqus software, in order to predict delamination growth and damage propagation while observing their effects on the critical buckling load.

Open access

Abstract

Laminated composite shell panels take part in several engineering structures. Due to their complex nature, failure modes in composites are highly dependent on the geometry, direction of loading and orientation of the fibers. However, the design of composite parts is still a delicate task because of these fiber failure modes, which includes matrix failure modes or other so-called interlaminar interface failure such as delamination, that corresponds to the separation of adjacent layers of the laminate as a consequence of the weakening of interface layer between them. In this work, impact-induced delamination represented as a circular single delamination is investigated, as it can reduce greatly the structural integrity without getting detected. Furthermore, attention is focused on its effect upon the post-buckling response and the compressive strength of a composite panel. The delamination buckling was modelled using the cohesive element technique under Abaqus software, in order to predict delamination growth and damage propagation while observing their effects on the critical buckling load.

Open access

Abstract

In the first and second chapter the article provides an overview of the currently used energy sources in Hungary and the most popular renewable energies. In addition, the Weibull estimation is presented, too. The subsequent chapter looks at some of the research results about the solar energy optimization with Weibull distribution. The study presented is a mathematical solution of the solar energy optimization with distribution. The final chapter contains a brief explanation of the results. This publication briefly summarizes a prototype solution for an estimation and forecast of solar energy and yield with Weibull distribution.

Open access

Abstract

This paper deals with the disturbance rejection, parameter uncertainty cancelation, and the closed-loop stabilization of the water level of the four-tank nonlinear system. For the four-tank system with relative degree one, a new structure of the active disturbance rejection control (ADRC) has been presented by incorporating a tracking differentiator (TD) in the control unit to obtain the derivate of the tracking error. Thus, the nonlinear-PD control together with the TD serves as a new nonlinear state error feedback. Moreover, a sliding mode extended state observer is presented in the feedback loop to estimate the system's state and the total disturbance. The proposed scheme has been compared with several control schemes including linear and nonlinear versions of ADRC techniques. Finally, the simulation results show that the proposed scheme achieves excellent results in terms of disturbance elimination and output tracking as compared to other conventional schemes. It was able to control the water levels in the two lower tanks to their desired value and exhibits excellent performance in terms of Integral Time Absolute Error (ITAE) and Objective Performance Index (OPI).

Open access

Abstract

This paper deals with the disturbance rejection, parameter uncertainty cancelation, and the closed-loop stabilization of the water level of the four-tank nonlinear system. For the four-tank system with relative degree one, a new structure of the active disturbance rejection control (ADRC) has been presented by incorporating a tracking differentiator (TD) in the control unit to obtain the derivate of the tracking error. Thus, the nonlinear-PD control together with the TD serves as a new nonlinear state error feedback. Moreover, a sliding mode extended state observer is presented in the feedback loop to estimate the system's state and the total disturbance. The proposed scheme has been compared with several control schemes including linear and nonlinear versions of ADRC techniques. Finally, the simulation results show that the proposed scheme achieves excellent results in terms of disturbance elimination and output tracking as compared to other conventional schemes. It was able to control the water levels in the two lower tanks to their desired value and exhibits excellent performance in terms of Integral Time Absolute Error (ITAE) and Objective Performance Index (OPI).

Open access

Abstract

A new two-level hierarchical approach to control the trolley position and payload swinging of an overhead crane is proposed. At the first level, a simple mathematical pendulum model is investigated considering the time delay due to the use of a vision system. In the second level, a chain model is developed, extending the previous pendulum model considering the vibration of the suspending chain. The relative displacement of the payload is measured with a vision sensor, and the rest of the state-space variables are determined by a collocated observer. The gain parameters related to the state variables of the chain vibration are determined by the use of a pole placement method. The proposed controller is verified by numerical simulation and experimentally on a laboratory test bench.

Open access
International Review of Applied Sciences and Engineering
Authors: N. ArikaraVelan, V. Deepak, N. Dhinesh Kumar, G. Muthulingam, S. Vanitha, P. Karthigai Priya, and Sachin Sabariraj

Abstract

In this study, vermicompost is replaced for fine aggregate in geopolymer concrete (GPC). Initially mix design is made for GPC and mix proportion is proposed. The vermicompost is replaced at 5%, 10%, 15% and 20% with M sand in GPC. Result indicates the 5% replacement with vermicompost based geopolymer concrete (GPVC) has the compressive strength of 32 N mm−2 (M30 grade) whereas the compressive strength of control specimen made with GPC is 37 N mm−2. Other replacement shows 21 N mm−2, 14 N mm−2 and 11 N mm−2 respectively. The 5% replaced concrete cubes and control specimen are tested at an elevated temperature of 200°C, 400°C, 600°C and 800°C and compared with the control specimen. There is no significant difference observed in weight lost at control (GPC) and GPVC specimen. An elevated temperature, the weight loss is almost 4% at 200°C because of expulsion of water from the concrete. Afterwards only 2% weight loss is observed in remaining elevated temperature. The compressive strength loss is observed at an elevated temperature in GPC and GPVC specimen because of thermal incompatibility between aggregate and the binder. EDX results show M sand and compost contains Si, Al, C, Fe, Ca, Mg, Na and K and it is similar in the elemental composition and SEM image confirms vermicompost contains fine particles.

Open access
International Review of Applied Sciences and Engineering
Authors: N. ArikaraVelan, V. Deepak, N. Dhinesh Kumar, G. Muthulingam, S. Vanitha, P. Karthigai Priya, and Sachin Sabariraj

Abstract

In this study, vermicompost is replaced for fine aggregate in geopolymer concrete (GPC). Initially mix design is made for GPC and mix proportion is proposed. The vermicompost is replaced at 5%, 10%, 15% and 20% with M sand in GPC. Result indicates the 5% replacement with vermicompost based geopolymer concrete (GPVC) has the compressive strength of 32 N mm−2 (M30 grade) whereas the compressive strength of control specimen made with GPC is 37 N mm−2. Other replacement shows 21 N mm−2, 14 N mm−2 and 11 N mm−2 respectively. The 5% replaced concrete cubes and control specimen are tested at an elevated temperature of 200°C, 400°C, 600°C and 800°C and compared with the control specimen. There is no significant difference observed in weight lost at control (GPC) and GPVC specimen. An elevated temperature, the weight loss is almost 4% at 200°C because of expulsion of water from the concrete. Afterwards only 2% weight loss is observed in remaining elevated temperature. The compressive strength loss is observed at an elevated temperature in GPC and GPVC specimen because of thermal incompatibility between aggregate and the binder. EDX results show M sand and compost contains Si, Al, C, Fe, Ca, Mg, Na and K and it is similar in the elemental composition and SEM image confirms vermicompost contains fine particles.

Open access

Abstract

This paper presents an experimental study of abrasive waterjet turning of an extrusion aluminum alloy (AlMg0,7Si). The aim of the paper is to determine differences of two methods from the point of view of machined surface quality and the depth of penetration, i.e., the diameter of the parts after the turning process. During the experiments, the traverse speed of the cutting head and the rotation of the turned parts were changed, other parameters, like pressure of the water, abrasive mass flow rate were kept constant. Diameter and some surface roughness parameters of the test parts were measured after the machining. On the base of experimental results, advantages, and disadvantages of two methods are explained in the paper.

Open access

Abstract

The ball and Plate (BaP) system is the typical example of the nonlinear dynamic system that is used in a wide range of engineering applications. So, many researchers in the control field are using the Bap system to check robust controllers under several points that challenge it, such as internal and external disturbances. Our manuscript proposed a position control intelligent technique with two directions (2D) for the BaP system by optimized multi Fuzzy Logic Controllers (FLC’s) with Chicken Swarm Optimization (CSO) for each one. The gains and rules of the FLC’s can tune based on the CSO. This proposal utilizes the ability of the FLC’s to observe the position of the ball. At our work, the BaP system that belonged to Control Laboratory/Systems and Control Engineering department is used for real-time proposal implementation. The results have been showing a very good percentage enhancement in settling time, rise time, and overshoot, of the X-axis and Y-axis, respectively.

Open access

Abstract

Many security vulnerabilities can be detected by static analysis. This paper is a case study and a performance comparison of four open-source static analysis tools and plugins (PMD, SpotBugs, Find Security Bugs, and SonarQube) on Java source code. Experiments have been conducted on the widely used Juliet Test Suite with respect to six selected weaknesses from the official Top 25 list of Common Weakness Enumeration. In this study, analysis metrics have been calculated for helping Java developers decide which tools can be used when checking their programs for security vulnerabilities. It turned out that particular weaknesses are best detected with particular tools.

Open access

Abstract

This paper robotic process automation is highlighted in modern business environments to understand about the progression of robotic process automation and how robotic process automation has brought changes to the world of business. Adoption of robotic process automation tools has raised lots of questions, but their deployment in a business has changed the outcome of the return on investment in a business by reducing cost and time taken on repetitive tasks. The paper is differentiating robotic process automation bot from artificial intelligence and robotics for the better understanding of lay audience. The paper also gives an insight about futuristic aspects of robotic process automation and robotic process automation 2.0.

Open access