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
Abstract
The Cyber-Physical and Vehicle Manufacturing Laboratory, a model Industry 4.0 laboratory, is applying new innovative solutions to improve the quality of education. As part of this, a digital twin of the lab was designed and built, where users can practice. In the virtual space, it is possible to apply the known robot motion types, and the tool centre and wrist speed have been measured virtually. Robot control tasks can be performed “offline” using parameters. This information can then be transferred to the actual physical robot unit. The stable diffusion 1.5 deep learning model generates 2D geometric shapes for trajectory, allowing users to perform unique tasks during education. The Google Colab cloud-based service was used to teach our rendered-type dataset. For the 3D simulation frame, we used V-REP, which was developed on a desktop PC equipped with an Intel Core i5 7600K processor, Nvidia GTX1070 VGA with 8 GB of DDR5 VRAM, and 64 GB of DDR4 memory modules. The following material describes an existing industrial six-axis robot arm and its implementation, which can be controlled and programmed while performing virtual measurements after integrating into a Cyber-Physical system and using deep learning techniques.
Abstract
With the escalating density of vehicles converging at road intersections, the surge in road accidents, traffic conflicts, and traffic congestion has emerged as a pressing concern. This research paper addresses these challenges by employing MC (manual control) techniques to mitigate encroachment issues at three selected intersections. These intersections were identified through a comprehensive analysis of the Ranking-based Instance Selection (RIS), enabling the design of suitable measures to facilitate smooth traffic flow and minimize the occurrence of crashes. In order to gather pertinent data, the study incorporates various parameters such as traffic volume, peak flow rate (PFR), traffic conflicts, accidents, and intersection inventory. Through the implementation of our proposed approaches, which involve both MC techniques and signalized operation, a supreme level of service (LOS) is attainable. Notably, our findings demonstrate a remarkable reduction in the volume-to-capacity ratio (v/c ratio) of up to 0.62. This paper thus serves as a significant contribution to the field of traffic management, offering practical insights for optimizing intersection design and effectively addressing the challenges posed by increased traffic density.
Abstract
Worldwide, precast and hybrid construction methods are becoming increasingly popular in the construction industry. But many problems occur during the fabrication, such as segregation, bleeding, scaling, plastic shrinkage, dust formation, honeycombing, sintering, high sorptivity, and high permeability and transportation. This problem may be caused by an ineffective curing process that affects the quality of concrete and construction. In addition, it provides inadequate and incomplete cement hydration that has a 20% negative effect on the desired properties of the concrete. Various researchers have demonstrated the components of self-curing lightweight concrete that can enhance strength and physicochemical properties, and address the above-mentioned issues. In this review, the role of the self-curing mechanism in lightweight concrete based on the various self-curing chemical admixtures such as polyethylene glycol (PEG), superabsorbent polymer (SAP), polyvinyl alcohol (PVA), sodium lignosulfonate and calcium lignosulfonate as self-curing agents are discussed in detail. Also, this paper briefly reports on the scope, significance, mechanisms, and tests for self-curing lightweight concrete. Overall, this review analyzes the possibilities of future research perspectives on self-curing lightweight concrete with sustainable materials and fibres with comparative technical information.
Abstract
Sensors are the main components in Cyber-Physical Systems (CPS), which transmit large amounts of physical values and big data to computing platforms for processing. On the other hand, the embedded processors (as edge devices in fog computing) spend most of their time reading the sensor signals as compared with computing time. The impact of sensors on the performance of fog computing is very great, thus, the enhancement of the reading time of sensors will positively affect the performance of fog computing, and solves the CPS challenges such as delay, timed precision, temporal behavior, energy, and cost. In this paper, we propose an algorithm based on the 1st derivative of the sensor signal to generate an adaptive sampling frequency. The proposed algorithm uses an adaptive frequency to capture the sudden and rapid change in sensor signal in the steady state. Finally, we realize and tested it using the Ptolemy II Modeling Environment.
Abstract
This study examines the economic optimisation of existing district heating systems. A new approach has been taken to solving a long-standing problem. The authors describe the input-output model of the system, the balance equations for the thermal equilibrium of the system, and the heat transfer system. From the balance equations of the series-connected system elements, the resultant heat transfer balance equation and the resultant power transmission equation are derived. In an example, the authors detailed how perturbations in some input variables can be corrected with other variables. The equations presented and the concepts introduced form absolutely new scientific results.
Abstract
Selecting the construction delivery method during the contracting period is one of the most important decisions determining the quality of large-scale infrastructure projects. Infrastructure projects have the most complex production processes in civil engineering. Infrastructure projects are among the most complex and resource-intensive endeavours in civil engineering due to their size, scope, multidisciplinary nature, regulatory requirements, financing challenges, environmental considerations, and the need for long-term planning and maintenance. Effective project management, collaboration, and a deep understanding of these challenges are crucial for the successful execution of infrastructure projects. Implementing such projects inevitably demands proper quality management throughout the project lifecycle. Two primary types of construction contracts are under implementation worldwide: Design-Bid-Build (DBB) and Design–and–Build (DB) contracts. In the Western Balkans region, both types of contracts are utilized for infrastructure projects, A noticeable trend is emerging toward transitioning from DBB to DB contracts. This paper provides a comprehensive analysis of quality management within the context of construction contracts with a focus on the roles and responsibilities of key stakeholders and how these factors affect the achievement of quality objectives while managing constraints related to cost and time. This research aims to improve construction practices by selecting an adequate type of contract for construction practices and ensuring successful project outcomes.
Abstract
In this study, nonlinear control design is presented for trajectory tracking of Tricopter system. A Fractional Order Proportional Derivative (FOPD) controller has been developed. The performance of controlled Tri-copter system can be enhanced by suggesting modern optimization technique to optimally tune the design parameters of FOPD controller. The Spotted Hyena Optimizer (SHO) is proposed as an optimization method for optimal tuning of FOPD's parameters. To verify the performance of controlled Tricopter system based on optimal SHO-based FOPD controller, computer simulation is implemented via MATLAB codes. Moreover, a comparison study between SHO and Particle Swarm Optimization (PSO) has been made in terms of robustness and transient behavior characteristics of FOPD controller.
Abstract
This paper introduces a stereoscopic image and depth dataset created using a deep learning model. It addresses the challenge of obtaining accurate and annotated stereo image pairs with irregular boundaries for deep learning model training. Stereoscopic image and depth dataset provides a unique resource for training deep learning models to handle irregular boundary stereoscopic images, which are valuable for real-world scenarios with complex shapes or occlusions. The dataset is created using monocular depth estimation, a state-of-the-art depth estimation model, and it can be used in applications like rectifying images, estimating depth, detecting objects, and autonomous driving. Overall, this paper presents a novel dataset that demonstrates its effectiveness and potential for advancing stereo vision and developing deep learning models for computer vision applications.
Abstract
Scour around the bridge piers is the main cause of bridge failure below any bridge pier placed within the waterways. It is more than hundred years back a number of researchers described the vortex shedding phenomenon and the resulting Aeolian tones from a circular cylinder. Since then there have been a large number of investigations dealing with various aspects of this phenomenon. In many practical works and situations, flow takes place around more than one obstruction and objects in close proximity. Invariably in all these cases, interference effects occur and the forces on the obstructions are much influenced by these effects. These effects play a key role in the structures like flow-induced vibration of TV and transmission towers, and in many other practical situations. In this research paper the changes in the flow field that occur due to the interference effects are shown, analysed and the results as given in literature are compared with the present experimental work. The features have been brought out in this paper mainly make use of stand and geometry of circular cylinders in close proximity and the flow part of geometry in side by side arrangement.
Abstract
As part of the energy design synthesis method, complex dynamic building simulation database was created with IDA ICE code for all family house building configurations for a considered problem. In this paper, the annual heat energy demand output parameter is considered to serve as basis of a building energy design investigation. The sensitivity analysis performed by Morris' elementary effect method was used. As the result of the sensitivity analysis of the output parameter, the most important input parameters can be identified, that influence the buildings' energy efficiency, that can support further building designs.
Abstract
The aim of the research was to carry out the One-at-a-Time sensitivity analysis of a tree burning experiment simulation with a novel fuzzy logic-based method. It was observed that the precent of the remaining tree is sensitive to the moisture content, the crown-base diameter and the tree height. The other variables, which are maximum mass loss rate, maximum heat release rate, and maximum temperature at the top of the tree are moderately sensitive or not sensitive to the selected parameters. The presented results can be used in sensitivity studies and wildfire simulations.
Abstract
This study uses a three-layer backpropagation neural network combined with particle swarm optimization to control the foamed bitumen in cold recycling technology. The foaming process of bitumen is non-linear and depends on dynamic temperature. By developing a neural network model, this study effectively captures the complex relationships between temperature, water content, air pressure, and the expansion ratio and half-life of foamed bitumen. The integration of particle swarm optimization enhances the accuracy and convergence of the neural network model by optimizing the initial weights. This optimization process improves the model's ability to predict and control the quality of foamed bitumen accurately. It serves as a valuable tool for the rapid development of high-quality cold asphalt design.
Abstract
This study targeted to investigate a type of excavation slurry by local available material in Najaf region. On the other hand, chief practises is supported the deep sides of foundation in particular pile foundation and, drilling oil wells. The results of slurries are checking, for seven properties, which includes the viscosity (apparent plastic and funnel Marsh), yield stress, density, acidity, and gel power (10–0 min). Which are 11.7367, 8.8733, 38.1667, 11.5467 mPa·s, 1.1045 kg m−3, 10.9067, and 11.2683 mPa·s, respectively. On the basis of the results tests for the above properties, that is possible to produce a product that conforms to the specifications of American Petroleum Institute specifications, and according to the requirements of the standard ACI 336.3R-93:2006 without additives. The rheological behavior improvement is achieved through the breakdown of the bundles of palygorskite fibers that normally make up the texture of these mudstones by increasing the time and speed of the shear force as soon as increasing the concentration of clay powder.
Abstract
The paper deals with the capacitance of cylindrical two-dimensional capacitor which consists of Cartesian orthotropic dielectric material. The determination of the capacitance of capacitor with orthotropic dielectric material by a suitable coordinate transformation is reduced to the computation of capacitance of an isotropic capacitor. It is proven that the capacitance of a Cartesian orthotropic capacitor can be obtained in terms of an isotropic capacitor whose dielectric constant is the geometric mean of the dielectric constant of the orthotropic capacitor.
Abstract
Fair treatment of individuals in a scheduling task is essential. Unfairness can cause dissatisfaction among workers, faster obsolescence of work tools and underutilization of others. The literature's definitions vary, and there is no clear definition of general scheduling tasks.
This article explores fair scheduling through the lens of final exams, aiming to extend decision support system methodologies. It proposes a method based on Lipschitz mapping to measure fairness and presents a pseudo-algorithm for estimating optimal trend lines.
The model and the algorithm are demonstrated using the example of final exam schedules. In this way, two feasible solutions can be measured and compared in terms of fairness.
Abstract
Building information modeling is one of the trends in the modern construction industry. The use of 4D building information modeling in addition to 3D building information modeling improves project planning and leads to higher quality of the final product with minimal wastage of resources. In addition, 4D building information modeling allows creating visual effects that can be shown to clients before construction begins. The study describes the ways in which 4D building information modeling can be used, as well as some of the notable benefits. The level of awareness of this technology and the level of its use in construction practice are also described. The final part describes the main problems and tasks of this field and possible ways to solve them.
Abstract
The role of building orientation in decreasing energy consumption for cooling purposes was examined in this study. A radiation analysis was performed during the early stage of the architectural design process on a proposed four-story apartment building located in Cebu. The building's performance was evaluated using the Grasshopper Ladybug plugin on a 3D model developed in Rhinoceros. Results indicated that the optimal building orientation that produced the lowest total radiation was situated at 290° from the center of the building, with a recorded value of 731,356 kWh m−2. Conversely, the building orientation that resulted in the highest total radiation was recorded at 210°, with a value of 755,596 kWh m−2. The analysis results were utilized to make informed decisions about building orientation based on environmental factors and surrounding areas. The use of computational design tools in the early stages of architecture design improves the process by enabling designers to optimize building performance and identify potential design issues early, thereby avoiding costly problems.
Abstract
The Electronic Throttle Valve (ETV) is the core part of automotive engines which are recently used in control-by-wire cars. The estimation of its states and uncertainty is instructive for control applications. This study presents the design of Extended State Observer (ESO) for estimating the states and uncertainties of Electronic Throttle Valve (ETV). Two versions of ESOs have been proposed for estimation: Linear ESO (LESO) and Nonlinear ESO (NESO). The model of ETV is firstly developed and extended in state variable form such that the extended state stands for the uncertainty in system parameters. The design of both structures of ESOs are developed and a comparison study has been conducted to show the effectiveness of the proposed observers. Numerical simulation has been conducted to assess the performance of observers in estimating the states and uncertainties of ETV. The simulated results showed that both full order and reduced order models of ETV have the same transient characteristics. Moreover, the effectiveness of two versions of observers has been examined based on Root Mean Square of Error (RMSE) indicator. The results showed that the NESO has less estimation errors for both states and uncertainties than LESO.
Magaspartok állékonyságelemzése
Mérnökgeológiai modell alkotás és numerikus analízis egy magyarországi példán bemutatva
Slope Stability Assessment of High Banks
Engineering geological model and numerical analyses, an example from Hungary
A meredek és instabil lejtők komoly műszaki problémákat okoznak, felszínmozgások miatt veszélyeztetnek településeket és infrastrukturális létesítményeket. A tanulmány egy kritikus régióban, a Balaton-part közelében elhelyezkedő magaspartok stabilitásának vizsgálatát foglalja össze. A bemutatott lejtő stabilitáselemzését különböző szoftverekkel – Plaxis, Geo5 és Slide2 – végeztük el, és összehasonlítottuk a kapott eredményeket állékonyság szempontjából. A modellezésből kiderült, hogy a magaspartok stabilitása nem éri el a szükséges biztonságot. Két fő azonosított tönkremeneteli módot lehetett elkülöníteni, melyek közül az egyik a talpponti, kissé alámetsző, összetettebb geometriával jellemezhető körcsúszólap, míg a másik a lejtő tetején az eróziós folyamatok miatt bekövetkező kisebb mozgás, lokális tönkremenetel. A számítások eredményeképpen a biztonság növelhető, megfelelően kialakított monitoring rendszerek segítségével.
Abstract
This study introduces the Chaotic Particle Swarm Optimization as an innovative variant of the traditional particle swarm optimization algorithm, addressing the issue of particle swarm optimization getting trapped in local minima with a low convergence characteristic during later iterations. Chaotic particle swarm optimization incorporates principles from chaos theory to enhance the swarm's exploration and exploitation capabilities. By introducing controlled chaotic behavior, particles exhibit more diverse and unpredictable movements in the search space, leading to improved global convergence and escape from local minima. The proposed method has been implemented and evaluated on benchmark problems to assess its effectiveness. The integration of chaos theory with particle swarm optimization offers promising opportunities for developing robust and efficient optimization techniques suitable for complex and dynamic problem domains in various real-world applications.
Abstract
The models compared in this study were applied to a catchment located in the western part of Slovakia in order to analyze and compare the amount of soil loss in different periods. Using of the empirical model universal soil loss equation, the average annual soil loss in the pilot basin was modeled for 2015–2020. The universal soil loss equation includes a topographic factor modeled using the USLE2D external model. In order to compare the empirical model and the physically-based model a continual sequence of individual rainfall events was created and used as an input to the physically-based EROSION-3D model. The results reflect different behaviors of erosion processes in a catchment together with a comparison between empirical and physically-based approaches.
A kritikai regionalizmus negyven évének elméleti összefoglalása nemzetközi és hazai nézőpontból
A Theoretical Summary of the Forty Years of Critical Regionalism from the International and Domestic Point of View
A jelen tanulmány célja a kritikai regionalizmus nemzetközi elméleti alapjainak és gyakorlatban alkalmazható elveinek ismertetése azzal a szándékkal, hogy a témában teljesebb ismereteket nyújtson, és azok megfelelően hasznosuljanak az épített környezet alakításának gyakorlatában. Célja továbbá, hogy az elméleti alapokat és gyakorlati elveket pontos meghatározásokon át kiterjessze a magyar viszonyokra, és ezzel a kritikai regionalizmus helyes értelmezését ösztönözze, megvizsgálva, hogy abból korunkban mi időszerű és folytatható. A tanulmány segítséget kíván nyújtani a hazai építészeti irányok közül annak az egynek a felismerésében is, amely magyar kulturális identitásunkra tekintettel van, és sajátunkként vállalható mind a hazai, mind a nemzetközi szakmai közösségben. Mindehhez a teljesség igénye nélkül, de a legfontosabb értelmezési irányok megjelölésével, a legnépszerűbb tévedések eloszlatásával és a legjelentősebb alkotók névsorának összegyűjtésével szeretnénk hozzájárulni.
Abstract
In this study, suitable fly ash (FA) was selected for agricultural purposes according to combined characteristic soils and water. The two FAs from the Tuticorin Thermal Power Plant (FA-TTPP) and Sripathy Thermal Power Station (FA-STPS) and physio-chemical analysis of soil and water samples from the five different sites (1–5) in Viruthunagar district, Tamilnadu is made. X-ray diffraction analysis (XRD) of FAs showed that quartz (SiO2), mullite (Al6Si2O), and hematite (Fe2O3) are available that enhance plant growth. The Fourier-transform infrared spectroscopy (FTIR) results confirmed that Si–O–Si, Al–O–Si, HO–OH, and OH bonding present in the FAs support to meet the required plant nutrients in the soil. Scanning electron microscopy analysis (SEM) of FA-TTPP revealed compact microspheres with regular, smooth, and irregular textures while FA-STPS showed glassy, unshaped fragments that may help to improve the texture of field sites. Energy dispersive X-ray spectroscopy (EDX) analysis found that FAs have essential macro- and micronutrients to minimize the soil nutrient and thus help to improve plant productivity. Sites 1 and 2 have acidic soil conditions and are recommended to use both FAs since they are alkaline in nature. FA can improve the water-holding capacity of sandy loam soils of sites 2, 3, and 4 due to the presence of fineness content in FA. Site- 1 has iron deficiency which can be remediated with rich iron FA-STPS. It is recommended to use optimum FA based on soil and water to improve agricultural efficiency.
Abstract
This article aims at illustrating the major factors of construction firms' failure from the perspective of constructors. Thirty-seven (37) factors are illustrated in this article. The factors are divided under 3 groups: financial, managerial and external. The study used the field survey technique (questionnaire) to collect the necessary data that serves its purpose. Results illustrate that the top 5 contributors are: delay in collecting payments from owner (financial group), poor work experience (managerial group), bidding strategy (managerial group), local political conditions, low profit due to high competition (financial group). Results indicate that the top factors are internal factors which could be handled and controlled by the company itself. The results of this study are the first step towards identifying the problems of contracting companies in order to understand them and try to find solutions that will raise the level of companies and ensure their continuity and success.
Geiger-féle kábelkupola parametrikus vizsgálata
Parametric Analysis of a Geiger Cable Dome
Egyre erőteljesebb igény jelentkezik a nagy alapterületű, belső alátámasztás nélküli térlefedések iránt. A különféle tartószerkezeti megoldások közé tartoznak a tensegrity szerkesztési elven alapuló kábelkupola-rendszerek, melyek a viszonylag egyszerű statikai viselkedésük és anyagtakarékosságuk mellett könnyű szerelhetőségük miatt is kedvező megoldást jelentenek. A kábelek nyomóerővel szembeni ellenállásának hiánya és a nagy elmozdulások okozta anyagi és geometriai nemlinearitás miatt azonban a hagyományos végeselemes eljárások nem alkalmasak a statikai analízis végrehajtására. A dinamikus ellazítás nevű, fokozatosan közelítő iteratív eljárás alkalmas a szerkezeti analízis elvégzésére. Ennél a módszernél elegendő az egyes csomóponti szabadságfokoknak megfelelő mozgásegyenleteket felírni és megoldani, nincs szükség a szerkezet merevségi mátrixának az előállítására. A kutatás célja egy dinamikus ellazításon alapuló numerikus modell létrehozása és kábelkupolák parametrikus vizsgálatának numerikus alapon történő végrehajtása. Az alkalmazott programkörnyezet a Rhinoceros 3D és annak Grasshopper almodulja, mely különösen alkalmas paraméteres vizsgálatokra. Az eljárásban a szabad paraméterek hatása, mint például a sugaras kiosztású szegmensek és a belső gyűrűk száma, a nyomott oszlopok hossza vagy az előfeszítés mértéke könnyen vizsgálható, ami komplex viselkedésű térbeli tartószerkezetek tervezésekor elengedhetetlen az optimális szerkezeti kialakításhoz.
Az elsajátítás értelmezése 20. és 21. századi térelméletekben, és egy vizsgálati keretrendszerének megalapozása
Interpreting Appropriation in Space Theories of the 20th and 21st Centuries, and Proposing a Framework for Its Practical Investigation
Tanulmányom az elsajátítás és a térbeliség kapcsolatának értelmezésével foglalkozik. Az elsajátítás olyan gyakorlatokat jelent, melyek során az ember birtokba vesz egy objektumot vagy helyszínt, és azt sajátjának tekinti. A dolgozatban kifejtem, hogy az elsajátítás mint jelenség alapvető téri jellemzőkkel bír. Rámutatok továbbá, hogy az elsajátítás koncepciója fontos elemét képezi Henri Lefebvre a tér társadalmi termeléséről alkotott elméletének. A Lefebvre munkásságát feldolgozó és továbbépítő szerzők eredményeinek felhasználásával az elsajátítás különböző értelmezési tartományait tárom fel: ezek szerint az elsajátításra tekinthetünk mint a környezet kreatív átalakítását és határok létrehozását előidéző gyakorlatra; mint várospolitikai kritikára; mint a spontaneitás megnyilvánulására; illetve mint jelentéstermelő médiumra. Ezentúl megvizsgálom, hogy az időbeliség hogyan képes befolyásolni az elsajátítás bármely aspektusát. A tanulságok felhasználásával célom egy olyan elméleti fogalmakat magában foglaló keretrendszer felállítása, mely az elsajátítás valós téri eseteinek kutatásához használható. Az épített környezetnek az elsajátítás gyakorlatain keresztül történő vizsgálatától azt várom, hogy az ember által megtapasztalt valóság számos összetevője közötti eddig ismeretlen összefüggésre világít rá.
Abstract
The main purpose of this paper is to propose a model for estimating the hysteresis damping ratio of moment steel frames and compare them with the results obtained using direct displacement-based design. In this study, different models of steel bending frames were examined by using several type of analysis to obtain this ratio. Thirty-steel frame models with 3, 6, 9, 12, and 15 floors and 3 and 6 bay with 6 m span length were analyzed and evaluated. The results showed that the equivalent damping ratio at the level of safety based on Jacobsen and Jennings, and the values of the equivalent damping relationships according to FEMA-440 vary from the empirical formula proposed in displacement-based design-2012. Therefore, in the ductility domain the exponential relationship form was more consistent with the results used. A new formula was proposed to calculate the hysteresis damping ratio, and it is more accurate than the empirical formula proposed in displacement-based design-2012.
Abstract
Expansive unsaturated soils present challenges in construction due to their moisture-induced behavior. This study proposes empirical equations to estimate the maximum wetting depth over time. Laboratory experiments and numerical analyses using SEEP/W software investigate wetting depth considering time and sand content in coastal and inland regions. Results reveal the significant influence of sand content on maximum soil moisture depth, emphasizing a recommended content above 30% to mitigate heave. The equations offer practical tools for assessing wetting depth, accounting for temporal and spatial variations. This research highlights the importance of wetting depth in addressing soil-related concerns and provides a foundation for further exploration of related factors.
Abstract
Promising method for disposal the pine wood waste through extrusion pelleting using sulphate soap as a natural binder is considered in the article. Prior to pelleting, the wood waste requires drying to a water content of no more than 10%. Analysis of pine wood waste drying in filtration mode yielded optimal parameters: a 20 mm layer thickness, temperature of 135 °C, and drying time of 3,900 s. The optimal content of sulphate soap binder was determined to be about 20%, resulting in reduced coke residue, increased volatile components, higher calorific value, and enhanced static strength. This binder facilitates formation of pellets at lower pressures, increases calorific value, and acts as a lubricant, reducing friction and associated energy costs.
Abstract
This work proposes an extended numerical scheme based on the finite volume method that is intended to solve a new morphodynamic model with porosity. The St-Venant equations and the Exner equation are coupled in this model, accounting for the variation of the porosity function
Abstract
Forced convection heat transfer was studied in a horizontally heated circular pipe with constant heat flux. Porous medium was created using 1 and 3 mm stainless-steel balls (porosity: 0.3690 and 0.3912). Reynolds numbers ranged from 3,200 to 6,500 based on pipe diameter, with heat flux rates of 6,250 and 12,500 W m−2. ANSYS Fluent simulated a 51.4 mm diameter, 5 mm thick, 304 mm long stainless-steel pipe. Results showed increased turbulence and eddy formation. Analysis revealed higher convective heat transfer coefficient, pressure drop, and Nusselt number with increasing Reynolds number. Nusselt number also increased with 1–3 mm ball diameter. 6% porosity increase reduced pressure drop by 84.4%. Nusselt number rose by 46.7% (Reynolds 3,200–6,500) and 4.36% (heat flux 6,250–12,500 W m−2).
Abstract
The influence of utilizing waste concrete aggregates on the flexural behavior of external reinforced concrete beams has been studied. Seven mixtures were prepared for this investigation where the concrete mixtures had different waste concrete percentages and admixtures. Also, seven beams were modeled by Ansys program and the properties of the seven mixtures have been used in the models to study their effects. It was found that using waste concrete aggregates has decreased the load bearing capacity and concrete ductility. It was found that the beam bearing capacity was decreased by 10.7% when using only waste concrete. Using admixtures have enhanced the concrete properties where the load capacity of beams has been increased by 39% when using silica fume and superplasticizer and the load capacity has increased by 44.6% when multi-admixtures have been used. Besides, it was found that using additives has enhanced the beam ductility significantly.
Abstract
This article aims at investigating rework cost, factors and effects in residential building projects in the West Bank – Palestine. Questionnaire survey is used to collect and rank the main factors and effects of rework from consultants' and constructors' point of view. Respondents show that more than 80% of the projects completed with rework cost of value greater than 5% of the total project cost. Overall, respondents' view concludes that the top rework factors include: mistakes in design, unskilled labors, unqualified subcontractors, non-conformance with required specifications, and bid awarding policy. Respondents indicate that the main effects of rework are cost overrun, project time extension, material waste excess and profit reduction. Spearman correlation test concludes a good correlation between contractors and consultants in ranking of rework factors and effects. Data collected from 47 residential projects reveal a high rework impact on cost overrun in construction projects. The results of this study would be helpful for researchers and professionals to guide their efforts to minimize rework in construction projects and to improve projects outcomes in term of cost, time and quality.
Abstract
The present study aims to determine the effects of blending cementitious materials on the mechanical and durability properties of high-performance concrete (HPC). Densified silica fume and fine-grounded metakaolin are used as supplementary cementitious materials (SCMs). A total of 16 mixes containing both binary and ternary blending of SCMs were chosen for w/b ratios of 0.4 and 0.3 respectively. The hardened properties tested for the HPC mixes were compressive strength at 7, 28, and 90 days, flexural strength at 28 days, and modulus of elasticity at 28 days. Maximum strength gains up to 15%, 38%, and 23% for compression, flexure, and elastic modulus were observed in ternary mixes compared to binary mixes. Stress-strain behaviour of ternary mixes indicates increased tolerance of stress for the least amount of strain in the specimens. Based on the experimental results, empirical relations were developed and checked with the existing codes and by earlier researchers. The durability properties tested for HPC were water absorption at 28 days, acid attack, and sulphate attack at 28, 56, and 90 days. Ternary mixes improved the pore structure of HPC, resulting in a 56% reduction in water absorption and a 34% reduction in compressive strength loss due to immersion in 5% H2SO4 at 90 days. The findings of the study endorse that ternary blending of SF and MK can improve the engineering properties of HPC, and a mix containing SF 10% and MK 10% is recommended for the best results.
Comparative Study on the Optimal Topologies
Összehasonlító tanulmány optimális topológiákra
The topology optimization is a leading tool in structural design. Due to the rapidly spreading need of the industry, commercial software are available in the market. Generally, these software are suitable for solving one subtask (preprocessing, postprocessing, stress calculation, etc.) but need some user manipulation to interconnect to one that is better for some other subproblem. This is the reason why we write a study on the available software and make suggestions on their usability. The purpose of this research is to briefly introduce selected software such as Rhino 3D, Grasshopper, Peregrine, Karamba, Galapagos, polyTop and PolyStress using topology optimization theory. Due to the demand to apply them for industrial applications, the additional goal is to make suggestions to make these software programs more user-friendly and to create algorithms to connect with software used in the industry, such as Consteel. This work also discusses the connected algorithms and optimization methods such as layout optimization by Peregrine, and topology optimization by polyTop and PolyStress. Several illustrative videos are provided as supplements. In addition to the text of this paper one can see demonstrations of the applications by the use of the provided YOUTUBE links.
Real Net Vault or Pseudo-Ribbed Net Vault?
Geometry, Construction and Building Technique of the Vault of the Reformed Church of Nyírbátor and the Nave Vault of the Franciscan Church of Szeged-Alsóváros
Valódi hálóboltozat vagy bordákkal díszített donga?
A nyírbátori ferences templom hajóboltozatának és a nyírbátori református templom boltozatának geometriája, szerkesztés- és építéstechnikája
In the present article, we revisit the question of the structural characteristics and building methods of two of the most famous Hungarian Late-Gothic net vaults, the nave vault of the Franciscan Church of Szeged-Alsóváros and the vault of the Reformed Church of Nyírbátor. Based on the data gathered by laser-scanning the two buildings, the geometric system of the two vaults, as opposed to the former state of research, differ significantly from each other. While the rib system and webbing of the vault of Szeged-Alsóváros have features characteristic of pseudo-ribbed net vaults and net vaults with webbing built with formwork, the vault of Nyírbátor is likely a real net vault structure with webbing built freehand. Furthermore, the rib system of the vault of Szeged-Alsóváros can be described by a single curved surface deductible from a circle segment, the rib junction points’ spatial positions in the vault of Nyírbátor are only describable by coordinates in the three directions of the space, not by an even surface. Based on the geometric descriptions, we also attempted to reconstruct the plausible building methods in both cases. Finally, we considered the results of the geometric analysis and the underlying construction ideas deduced from it and gave a new evaluation regarding the earlier reasonings for the strong building connections of the two churches in regard to the guilds and master builders.
Az esztergom-belvárosi kálváriakápolnák és stációk összművészeti jelentősége
The Overall Artistic Significance of the Chapels and Stations of the Calvary in Esztergom-Belváros
A hazai századforduló építészetének egyik kiemelkedő emléke az esztergomi belvárosi Kálvária-hegyen található összművészeti együttes, mely két kápolnából és 14 épített stációból áll. A több évtizedes elhanyagoltság után néhány évvel ezelőtt megkezdődhetett az értékek kutatása és mentése, az alsó kápolnát sikerült részben felújítani, ám a felső kápolna ez év elején már az összedőlés határára került. Közösségi és egyházmegyei kezdeményezésre és a város vezetésének segítségével az utolsó pillanatban sikerült megmenteni. A tervezést és felújítást megelőző kutatásaink olyan építészeti és művészettörténeti gazdagságot tárnak elénk, melyek országos szintű értékek, bemutatásuk és védelmük közös feladatunk. A restaurátori kutatások és értékmentések megtörténtek, és megindult a rekonstrukciós munka is. E cikk alapvető célja, hogy a szakma és a közösség megismerhesse, magáénak érezhesse ennek az együttesnek hazánkkal összefonódott sorsát, mely nemcsak közös múltunk tanúja, de közös jövőnk záloga is egyben.
Finding Groundwater in East and West
Comparing Methods of Finding Groundwater in Al-Karaji’s Treatise on The Extraction of Hidden Waters and Vitruvius’s Treatise on The Ten Books on Architecture
Földalatti vízvezetékek Keleten és Nyugaton
Al-Karaji A rejtőző vizek kitermelése és Vitruvius Tíz könyv az építészetről című traktátusának összehasonlító elemzése a földalatti vízvezetékek tekintetében
Hydraulic systems were built by ancient civilizations, notably the Persians and Romans, to deliver water to their residences where the water supply was scarce. Qanats were invented by the Persians to transfer water from aquifers to the surface, and aqueducts were built by the Romans to transport surface or underground water from its sources to distribution points in cities. Finding groundwater is a similarity between these two historical systems. This research compares ancient methods used by Persians and Romans to locate areas with abundant subsurface water. The oldest existing historical documents that recorded ancient ways of tracking groundwater, Al-Karaji’s treatise on qanats and Vitruvius’ treatise, were investigated with the qualitative content analysis method. As a result, historical means are divided into two categories in these two treatises including natural indications and practical tests. Natural indications consist of mountains and rocks, features of steppes, plants, vapours and dew, the whistles of the wind, and alluvial fans. An inverted container, a fleece of wool, an oil lamp, and a fire are instances of practical tests. Although these two treatises were authored over a ten-thousand-year interval and the structures of water systems differ, there are commonalities between ancient methods of tracing underground water.
On the Buckling of the No-tension Material Masonry Column
A húzószilárdság nélküli téglapillér statikai modelljéről
Masonry columns, subjected to eccentric compression, crack due to tension if the eccentricity is larger than the size of the core of the section. Previous studies have assumed that the cracks have so small spacing that the cracked tension side can be neglected during the analysis.
The critical load can be determined using this assumption. However, experimental experience has shown that the cracks have large spacing, approximately equal to one and a half times the cross-section height. Therefore, the crack-free parts between the cracks influence the lateral deflection and the critical load. Considering the above-mentioned phenomenon, we determined the elastic critical buckling load of the cracked masonry column.
Abstract
A railway on 4 m height embankment is being built in the south of Iraq. The railway alignment is extending on a compressible soil experienced impermissible settlement according to the results of soil investigation of the soil at the project site. A trial for reducing the settlement was done adopting sand piles. Nonlinear analysis was conducted to evaluate the settlement of soil before and after using the proposed technique.
The results indicated that without any improvement, the expected total settlement of the railway embankment on the compressible clay layer is 170.2 mm. By inserting granular piles of diameter 0.3 m, it was obtained settlement decreases to 88.7 mm with reduction being in range of ∼48%.
Abstract
The efficiency of using photovoltaic panels significantly depends on the climatic conditions and the power of the consumer. The evaluation of the efficiency of using the battery of the photovoltaic panel depending on the climatic conditions and the power of the consumer was carried out by the method of simulation modeling. A new type of storage battery allows to accumulate excess and compensate for the energy deficit due to the capacity of the batteries, and in case of their complete discharge - due to connection to other sources of electrical and thermal energy. The temperature field on the surface of the solar panel is constructed based on numerical simulation. The temperature ranges from +70.4 to +127.5 °C. In the main area of the panel, the heat flow ranged from 3,200 to 7000 W m−2.
Abstract
Speech scrambling aims to distort speech signals to prevent unauthorized listeners from understanding them, but conventional techniques are vulnerable to attacks. Therefore, more robust and secure speech scrambling algorithms are needed to ensure sensitive communication security. A proposed scheme uses a particle swarm optimization algorithm to generate a random key and optimize the level of noise in the scrambled signal, along with two transformations Multiwavelet and Arnold techniques to improve complexity and security. The proposed algorithm has been evaluated using various performance measurements and has demonstrated superior encryption performance than other similar audio encryption schemes with key space equal to 128 × 2.718. Further research and development in speech scrambling are essential to guarantee secure communication in sensitive contexts such as military and intelligence.
Abstract
With the development of society and economy, people pay more and more attention to thematic landscape architectural design featuring various cultures. Landscape architectural design is no longer only satisfied with the standardized, identical design style, but should focus on some specific cultural communication functions. In the thematic landscape architectural design, the use of cultural symbols can reflect the characteristics of the park. Through some research and practical design, the design method of using cultural symbols in landscape architectural design is summarized: from finding cultural elements to design language transformation.
Abstract
This study presents the frequency control of hybrid deregulated power system. The power system is supplied with appropriate system non-linearity's for practicality. A resilient model predictive control based two degree of freedom proportional integral derivative controller is designed. The Covid-19 based optimization algorithm is applied for optimization purpose. The impact of solar and wind on system dynamics are also examined. Further, the capacitive energy storage is also incorporated to check its influence. The distribution companies' participation matrix changes with market fluctuations, so the matrix is varied to check its impact. Lastly, sensitivity assessment is performed to analyze the strength of proposed controller optimized gains achieved under nominal conditions.
Abstract
The application of natural ventilation strategies in high-rise office buildings is considered one of the most promising trends to address high energy performance and enhance the indoor thermal comfort levels in interior office spaces. In this regard, this study attempts to assess the potential of natural ventilation strategies of a specific, previously investigated, envelope design of a high-rise office building located in a temperate climate zone. Different summer natural ventilation approaches were tested using the building energy simulation program IDA ICE 4.8, evaluating thermal comfort and energy demand. The findings indicated that considerable energy savings can be achieved, compared to conventional mechanical ventilation and air conditioning systems.
Abstract
Previous studies introduced the shiftability condition for successful gearshift, based on the dog clutch kinematics model containing several parameters. This study analyzes the effect of these parameters on the dog clutch shiftability. A method to study the impact of parameters is proposed. The influence of chosen parameter domains is shown. Their influence is recognized based on the shiftability map and the engagement probability. The initial relative position showed a periodic effect within one pitch region. The teeth number, axial speed, and the backlash positively affected the engagement probability, while the mismatch speed and the overlap distance showed a negative effect. The analysis showed lower limit values for the axial speed and the backlash but higher limit values for the mismatch speed and the overlap distance.
Abstract
The current research aimed to obtain mean pressure distribution over an air-inflated membrane structure using Computational Wind Engineering tools. The steady-state analysis applied the Reynolds-Averaged Navier-Stokes equations with the
Abstract
Due to the increase in earthquake activity in Iraq and Middle East during the last two decades, the study and understanding of probable destructive action and the best method to mitigate this effect became more important. So, many improvements and mitigation methods can be used. In this study, the use of permeation grout technique was adopted to prevent the existing soil condition in urban area by using cement kiln dust and bentonite clay. The tests were executed by using 1 g shaking table apparatus to simulate a sinusoidal motion (vibration) at specified different frequencies. The liquefaction phenomena were observed for loose saturated sand at 60 s, 25 s, and 10 s for 0.5 Hz, 0.75 Hz, and 1 Hz, respectively. After mitigation process, the soil liquefaction did not occur until 100 s, 60 s, and 30 s, for the same mentioned frequencies. Besides, the use of cement kiln dust decreases the liquefaction potential and increase the factor of safety.
Abstract
In this article, polymer-modified concrete was studied to present the effect of using additives on its mechanical properties. This will be achieved by employing a high-performance super plasticizing admixture that significantly enhances polymer-modified concrete mechanical capabilities. The study indicates that the polymer styrene-butadiene rubber (used increases concrete mechanical properties by 10% by weight. When the dosage exceeds 10% by weight of cement, the compressive, tensile, and flexural strengths of polymer-modified concrete are diminished. With the addition of a superplasticizer with a ratio of 1.2%, regular polymer-modified concrete compressive strength has increased from 34.3 to 42.9 MPa for a 10% polymer/cement ratio. Additionally, this superplasticizer enhanced the Material's flexural and tensile strength.
Abstract
Multimodal biometric systems have been widely implemented in a variety of real-world scenarios due to their ability to overcome limitations associated with unimodal biometric systems. This paper is focused on the combination of the face, ear and gait in a unified multimodal biometric identification system using handcrafted features. These approaches provide robust and discriminative features to solve the biometric problem. In this research, speed up robust features and histogram of oriented gradients approaches have been used to extract features from face, ear and gait. The extracted features are optimized using genetic algorithm and classified using Levenberg-Marquardt backpropagation neural network. The system performance is evaluated on constrained and unconstrained dataset conditions.
