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
Several biopolymer applications in geotechnical engineering have been adopted in recent years, notably dust control, soil strengthening, and erosion control. Although biopolymer soil treatment approaches can assure engineering efficiency while satisfying environmental protection standards, this technology requires more validation regarding site adaptability, durability, and economic feasibility. The influence of biopolymers on soil behavior is discussed within geotechnical engineering applications and practices, including soil consistency limits, strength and deformation parameters, hydraulic conductivity, soil-water properties, and erosion prevention.
Laboratory studies were performed to confirm the behavior of the treated soil, including Atterberg limits, proctor, and direct shear tests utilizing two types of biopolymers: guar gum and xanthan gum.
Abstract
Many sports organisations operate as non-profits, but the emphasis and role of for-profits in this sector cannot be avoided. Today, sports activities are connected to the business sector and generate profit, hence, sports sector is a decisive part of the economy. Sport profile companies differ in their organisational strategy formulation approach. The main focus was to learn more about their strategy approach and market behaviour. 350 sports business organisations were involved in a survey of 3,248 companies, and the Chi-square test, variance analysis, and principal component analysis were applied to the sample. Results showed that 75.7% of the responding sports companies had no written strategic plan. The availability of written strategies seemed to depend on the organisation's scale. The market-following behaviour was confirmed in the case of smaller sports enterprises. Fitness service providers appeared to follow a market-leading behaviour. Growth, investment, and development naturally emerged as essential factors for companies with higher sales revenue and operating sports facilities, and they were relatively less important in sports goods production and trade. Most of the results showed that in the sports business sector, large-scale organisations focus on strategic-related issues more than other players in the industry.
Abstract
One critical issue in the tracking systems based on photovoltaic (PV) is how to harvest highest power of the photovoltaic array; particularly when the system is operating in partially shaded conditions (PSCs) or varying irradiances. This study proposes particle swarm optimization (PSO) hybridization and cuckoo search algorithm (CSA) methods for maximum power point tracking (MPPT). The effectiveness of the proposed algorithm is validated and examined under various irradiance patterns. A comparison study in performance has been conducted between the proposed hybrid CSA-PSO method with the conventional P&O and PSO techniques. Several tests have been performed based on numerical simulations utilizing the programming software MATLAB/Simulink. The results demonstrated that the suggested hybrid technique yields smaller tracking time, higher power and greater efficiency than those of other traditional algorithms.
Abstract
Composite materials are vulnerable to impacts that may occur during their use. Such transverse loads represent a significant threat to these materials because they can cause damage that is difficult to detect. Thus, understanding the mechanical behavior of composite materials during impacts is crucial for improving their damage resistance. Therefore, this study investigates the response of two commonly used composite panels in maritime transportation—a PVC core sandwich composite and a laminated GFRP composite—under quasi-static indentation (QSI). Using numerical simulations with Abaqus/Explicit, this investigation aims to anticipate mechanical characteristics and damage patterns during low-velocity impact. Results show a strong correlation between numerical and experimental data. The force-displacement curves aid in understanding damage sequences, with predicted maximum loads at 1.43% and 6.45% accuracy for laminated and sandwich composites. Both exhibit significant damage, including permanent indentation, matrix cracks, fiber fractures, and prevalent delamination around the impact point.
Abstract
This study evaluates metallic yield dampers, specifically slit steel dampers, for protecting steel beam-to-column connections during seismic events. Finite element model simulations were conducted for the damper and its connection. Analysis of circular parameters, like the radius slot, showed that appropriately sized slit dampers exhibit advantageous seismic behavior. Moment-rotation, hysteresis curves, and plastic stresses comparisons indicate efficient energy absorption. The maximum moment was 25% lower than conventional samples. The slit steel damper model with a ductility factor of 3.5 allows significant plastic deformation before potential failure. Results emphasize the slit damper's potential for optimal performance in steel frames, suggesting its use for efficient energy absorption.
Abstract
Geopolymer concrete (GPC) is a rising eco-conscious substitute for traditional cement-based concrete, bringing the construction industry closer to sustainability. Self-compacting geopolymer concrete (SCGC) enhances the concrete flowability and fills the congested reinforced areas without vibrators in concrete structures such as bridges, tunnels and canals. This study aims to analyze the impact of silicon dioxide nanoparticles (NS) on the rheological and mechanical properties of SCGC to optimize the dosage of NS in SCGC. For this purpose, NS (0–6%) blended in partially distributed binders of fly ash and ground granulated blast furnace slag (50:50) with 0.5 alkaline binder ratio, 2% superplasticizers (9 kg m−3) (MasterGlenium SKY 8233) and 12% extra water (54 kg m−3). Sodium silicate solution and sodium hydroxide ratio of 2.5 was used for this study. It is observed that SCGC with 3% NS replacement complied with the guidelines of EFNARC. According to the T50cm slump flow test, V-funnel test, and L-box test results meet the guidelines of up to 4% NS replacement, and 3% NS addition offers excellent mechanical properties in SCGC. This study concluded that the replacement of 3% of NS improved the fresh and hardened properties of SCGC, which can apply to construction.
Abstract
Today, the role of humans is changing rapidly in both industrial production activities and services. Mediocre, easy-to-learn activities can be performed more efficiently by machines; mediocre knowledge is being devalued while the importance of high-level skills is increasing. As a result, in all sectors of the economy, and especially in engineering, new approaches to expert training are needed; people must learn to hand over certain decision-making roles and to control the processes supported by AI rather than compete with it. STEM education has a responsibility to achieve these goals and must develop appropriate tools for engineering education. This paper presents a complex didactic methodology for competency-based education in engineering bachelor programs. An important element is the mathematical competency map, which shows the importance and place of mathematical and algorithmic (coding) knowledge in engineering topics. Another element is the systematic testing of mathematical knowledge in non-mathematical contexts in engineering courses. We provide an overview of our achievements in applying the developed toolset and improving the efficiency of mathematics teaching in engineering bachelor programs.
Abstract
Using finite element methods, residual stresses were estimated in pipe welds. Experiments were also conducted to verify the numerical results. An alternative to a three-dimensional model was used to simplify the numerical calculation for residual stresses investigation. Model predictions were validated by measuring residual stresses using X-ray diffraction. As compared to measured residual stress distributions, the computational approaches developed in this study can accurately predict welding residual stress distributions. The focused welding parameters have a significant impact on residual stresses even when all the other parameters are the same.
Abstract
The predictive maintenance of permeant magnet synchronous motor is highly required as this kind of motor has been commonly employed in electric vehicles, industrial systems, and other applications owing to its high power density output, as well as the regenerative operation characteristics during braking and deceleration driving conditions. One of the most important causes of PMSM failure is the stator short and drive switches failure. These problems have attracted more attention in the field of deep learning for fault detection purposes in the early stages, to avoid any system breakdown, and to decrease the risk and price of maintenance. In this paper, we investigate the possibility of detecting the electrical faults in PMSM by generating our data which includes current signals that have been analyzed and preprocessed by applying Continuous Wavelet Transform (CWT) to select the reliable features this conversion will be used to train ResNet 50. The evaluation metrics have shown that ResNet 50 achieves an accuracy of 100% for the classification of faults.
Assessing Novel Fiber Reinforcement Against Conventional Mix by Using Both Natural and Synthetic Fibers in Concrete with Statistical Performance Analysis
A természetes és szintetikus szálak felhasználásával készülő szálerősítésű és a hagyományos beton keverékek összehasonlítása, értékelése és statisztikai elemzése
This research investigates the effect of incorporating innovative human hair fibers (HHF) and polypropylene fibers (PPF) into concrete, which has been observed to enhance the material’s strength characteristics. These fibers augment the concrete’s tensile strength and resilience, fortifying it against cracks and elevating its overall endurance. This research delves into the impact of reinforcing concrete specimens with human hair and polypropylene fibers. These specimens are employed in cube, cylinder and flexural beam tests. Both fresh and hardened properties, such as compaction factor and slump, and compressive, split-tensile, and flexural strength at varying curing periods (28 days and 90 days) and the ratios (1%, 2%, and 3%) are considered by weight of cement. Specifically, the 3% polypropylene fiber concrete mix exhibited the highest average compressive strength at both 28 and 90 days, while the 2% polypropylene fiber mix showed the highest split-tensile strength. Flexural strength results followed a similar trend. Results show that 3% HHF addition leads to notable improvements in concrete strength properties, albeit not as significant as with polypropylene fibers. Statistical analysis, including independent samples Kruskal–Wallis tests, was conducted to compare the distributions of strength values across different groups. The statistical analysis indicates significant differences in strength distributions across groups, with p-values below the significance level of 0.05. This underscores HHF’s potential as a sustainable alternative in construction applications, contributing to enhanced concrete strength.
Abstract
The integration of Autonomous Vehicles (AVs) into our modern society hinges on gaining widespread acceptance from potential road users. To indicate the preparedness of these road users and elucidate their perspectives regarding the use of AVs in future, it is imperative to conduct surveys gauging public acceptance and satisfaction with this emerging mode of transportation. This paper reports the results of a comprehensive questionnaire study involving 1,000 individuals in Gyor City. The survey's primary objective was to assess participants' attitudes and willingness to embrace autonomous vehicles within the city's road networks. The study delved into various socio-demographic factors, such as age, gender, and employment status, while also exploring participants' prior knowledge and opinions regarding the advantages and limitations of AVs. The findings reveal a generally favorable disposition among the public toward the inclusion of AVs in urban traffic, paving the way for the acceptance of mixed traffic patterns. Notably, respondents in younger age groups exhibit greater enthusiasm for incorporating AVs into their daily transportation, whereas individuals aged 65 and above express more reservations, displaying a conservative outlook. Furthermore, participants with prior knowledge and a deeper understanding of AVs exhibit a markedly more positive inclination toward this emerging technology compared to those lacking such familiarity.
Linear and Centralised Net Vaults
Geometry-Based Building Archaeology Presented on the Net Vaults of the Fortified Church of Mediaş
Lineáris és centralizáló hálóboltozatok
Geometria alapú épületkutatás a medgyesi erődtemplom hálóboltozatainak példáján bemutatva
This article presents an objective, point-cloud-based geometric description of the nave, apse, and sacristy vaults in the fortified church of Mediaş (RO; Medgyes, Mediasch). The description includes the global geometry of the rib systems and the connections between the webs and ribs in each vault. Based on these, we classify these structures into the geometry-based typologies for the global geometry of the rib system and the rib-web connections we established based on our previous works. Additionally, based on the vaults of Mediaş, two rib-system subtypes have been defined: centralising and linear vaults. The relationship between these subtypes and the concept of cylindric and spheric vaults, as well as their connection to the ‘pattern’ of the net vaults is discussed. Based on the geometric descriptions, we also discuss the possible building strategies and techniques of these vaults and consider the periodisation of the building.
Abstract
Design and testing of real materials is a costly process and usually requires some specific equipment. To alleviate this task numerical methods can be leveraged. In this work we show possible modelling technique for closed-cell material structure using Weaire–Phelan unit cells. As an example existing aluminum structures were used and modelled parametrically, allowing to establish different geometrical models for different applications. Numerical simulations for compression was also done on the developed models to reveal the material response. The influence on the cell wall thickness and the friction between the material and the compression plate was investigated. It was found that the friction coefficient has no significant effect on the material response, except in the case where bonded connection was assumed. It was also demonstrated that material response and the porosity controlled by cell wall thickness have an approximately linear relationship with each other. This method proved to be a flexible and alternative solution of real laboratory tests and targeted to reduce costs of material design.
Típus-lakóépületek Magyarországon
Standardised Residential Buildings in Hungary
Az elmúlt ötven év során sok iparágban, például a ruha- és a bútoriparban, az egyedileg tervezett és gyártott, kisszériás áruk helyét egyre inkább a sorozatgyártott tömegtermékek vették át a fejlett országokban. Mivel a sorozatgyártás lehetőséget biztosít a termékek optimalizálására, azok sok esetben olcsóbbak és kiszámíthatóbb minőségűek lehetnek, mint az egyedi termékek. Ez pedig egy megfelelően széles választék fenntartása mellett kifejezetten vonzó a vásárlók többsége számára.
Bár az építőipar más iparágakhoz képest lassan fejlődik, az épületelemek előregyártása egyre jellemzőbbé válik Európában a szakképzett munkaerő hiánya és a helyszíni kivitelezés kockázatai miatt. Egyelőre ugyan a legtöbb épület még egyedi tervek alapján születik, de az előregyártás terjedésével, a nagy fejlesztő cégek térnyerésével és a lakáspiac drágulásával kérdéses, hogy a lakóépületek meddig lesznek képesek megőrizni az egyediségüket vagy egy hasonló folyamatnak leszünk hamarosan a szemtanúi, mint ami a ruha- és a bútoriparban lejátszódott.
Mivel az épített környezettől elvárt egyediség összefügg az ember megélt tapasztalataival, a felvázolt jelenség apropóján a jelen cikk azt vizsgálja, hogy Magyarországon milyen motivációk álltak a formai szempontból egynemű lakókörnyezetek létrejöttének hátterében. A példák felsorolása mellett a cikk felvázol egy keretrendszert, amin belül értelmezhetővé válnak azok a társadalmi folyamatok, amik megmagyarázzák, hogy miért és miként építünk típusépületeket. A javasolt rendszerezés szempontként vonja be a típusépületek elemzésébe, hogy ezek az épületek fentről lefelé vagy alulról felfelé építkező folyamat eredményei-e, elterjedésük projektspecifikus-e, és hogy maguk az épületelemek szabványosítottak-e.
A jelen cikk a körülöttünk lezajló folyamatok értelmezésén felül egyfelől bemutat példákat arra, amikor a típusépületek használatával harmonikus épített környezet jön létre, másfelől pedig bemutatja azt is, hogy milyen okok állhatnak amögött, amikor a típusépületek nem válnak be. Mindez segíthet abban, hogy elkerüljük a jövőben az olyan épületek sorozatgyártását, amelyek borítékolhatóan nem lesznek képesek hosszú távon is megőrizni társadalmi elfogadottságukat.
Abstract
The immediate vicinity of buildings of different floors causes damages of the smoke and ventilation channels work of the low-rise buildings. This is dangerous for the resident's health and lives. To determine the impact of high-rise buildings on the operation of air channels of a nearby two-story building, experimental research has been carried out in a wind tunnel. Charts and analytical formulas have been designed for determining the buildings aerodynamic coefficients depending on wind directions and the channels height. An increase of the channel height results in an increase in static rarefaction in smoke and ventilation channels. Increasing rarefaction increases the efficiency of the natural ventilation system and ensures the residents health and life.
Abstract
Springs are the most basic mechanical elements used in transmission mechanisms. The rapid development of the computer and cellular industry has encouraged spring manufacturers to develop the industry to produce very small springs. Most computer-aided design programs for mechanical parts provide the possibility of designing these parts, as these programs include different types of decisions. All these decisions require coordinates for geometric data as well as metadata. The paper aims to develop software programs to design and analyze springs as one of the most significant mechanical elements used. This paper aims to develop a design software of a helical spring system, where this software is built using a computer program in the language of Visual Basic Version 5. When the user enters data into the system, the system will perform a series of complex calculations in the system, then provide a detailed report on all the engineering dimensions of the spring, and test its efficiency. The output of the software shows the required spring wire parameters. The software was tested with test data from the open literature, and the required wire spring parameters were obtained.
Effect of Bonding Type on the Failure of Reinforced Concrete Beam Strengthened with In-Situ High Performance Fibre Reinforced Concrete Layer
A kapcsolat típusának hatása helyszínen öntött szálerősítésű, nagyszilárdságú betonhabarccsal megerősített vasbeton gerenda tönkremeneteli módjára
High performance fibre reinforced concrete (HPFRC) materials with tensile hardening behaviour can effectively be used for strengthening reinforced concrete beams. A perfect bond between the original and the reinforcing layer cannot be formed, the load-bearing capacity and ductility of the strengthened beam can significantly be affected by the interfacial bond strength between the contacting surfaces. In this paper, beam retrofitting with cast in-situ strengthening type is examined. The purpose of this experimental study is to investigate the impact of the different bond types on the load-bearing capacity, ductility, and failure mode of the strengthened beams in the case of cast in-situ strengthening. Twenty-four beam tests were performed with untreated and rough surfaced beams, with or without connecting elements. The effect of the bond type proved to be significant regarding the failure mode in the case of compression side strengthening, stronger bond resulted in higher load bearing capacity and ductility, too. When tensile side reinforcement was investigated no average increment was experienced in the maximal force and ductility due to the stronger bond. Based on the results, it can be concluded that the generally applied analytical models that assume perfect connection may lead to exaggerated results in the case of a compressed side HPC-strengthened beam. Therefore, it is necessary to develop a model that considers the effect of the imperfect bond.
Abstract
Numerous studies have proven that digital development positively affects economic growth. This study aims to confirm or refute the positive impact of digital evolution on economic growth by applying the dimensions of the International Digital Economy and Society Index (I-DESI). The analysis refers to the period 2015–2020 of the European Union member states. The study's novelty is that the I-DESI index has yet to be used in research to investigate the relationship between the digital transition and GDP production. The present study, therefore, goes one step further than the previous typical DESI-GDP models. The research uses Pearson correlation and F-statistic analysis to show the relationship between the variables. The study confirms that digital development has positively impacted the economic growth of EU member states. This result was confirmed by both Pearson and Spearman correlation. However, the results are ambivalent. The empirical results indicate that the more digitally developed member countries had a higher GDP per capita. However, the positive effect is different. The results confirm that the development of digitalization and GDP increased more dynamically in the more digitally developed EU member states than in the less developed member states. Therefore, an increase in the backwardness of the less developed member countries and not a catch-up can be observed in the period under review.
A miskolci Avasi késő gótikus templom nyugati rózsaablaka
The Western Rose Window of the Late Gothic Avas Church in Miskolc
A miskolci Avasi Református Templom [3530 Miskolc, Papszer u. 14. hrsz.: 2405, azonosító: 2926, műemléki törzsszám: 848] nyugati falát egy kis méretű kerek, mérművekkel díszített ablak – rózsaablak – töri át, amit az 1980-as években kibontottak és újrafaragtak. A kőrestaurátori munkákról kevés feljegyzés áll rendelkezésünkre, így az eredeti ablak kőtöredékeinek holléte is ismeretlen volt. A rózsaablak kőtöredékeinek megtalálása, beazonosítása és konzerválása lehetővé tette bemutatását egy, a legutóbbi, 2019-es felújítási munkálataihoz kapcsolódó állandó építészettörténeti kiállításon a templom falain belül. Az esettanulmány a rózsaablak (ismert) történetét mutatja be az első ismert ábrázolásoktól, a Szehlo Ottó-féle téves felmérésen keresztül egészen a jelenkori állapotig; az ablak szerkesztésének elvi menetét, amely kontextusba helyezi a Sztehlo-féle vázlatokat és válaszol az ábrázolásokkal kapcsolatban felmerült kérdésekre; foglalkozik a kőanyaggal és a beépítési móddal, amelynek kiemelt jelentősége a kőrestaurálás folyamatában és a kiállításánál volt, hiszen a kőszerkezet állapota kritikus volt, egyes részei mozdításra törnek, kiállításához a szilárdítása és kezelése elengedhetetlen volt.
Abstract
This study highlights the effectiveness of the response surface method in predicting the properties of hardened concrete containing spent foundry sand and manufactured-sand. In current research, different mix proportions are prepared with spent foundry sand and manufactured-sand as partial replacements for fine aggregate. The workability, strength, and durability studies are conducted on all concrete mixes. The test results confirm that the inclusion of 20% of spent foundry sand is optimum for enhancing the strength and durability. Also, the inclusion of 20% of spent foundry sand in manufactured-sand concrete also possesses optimum results in strength and durability. Further, the response surface method has been employed to develop a model for compressive strength prediction. The R-squared and residual sum of squares of error for the compressive strength model were 0.9863 and 2.345, which confirms the goodness of the fit.
Abstract
Local scour poses a grave threat to bridge foundations, potentially causing catastrophic collapses. This study uses FLOW-3D with the Reynolds-Averaged Navier-Stokes model to analyze pier scour and dune formation under bridges. It focuses on submerged debris shapes near the water's surface. Results closely match experiments when specific conditions are met. The study introduces an innovative approach to debris impact assessment. Instead of traditional methods, it proposes a novel equation accounting for debris's effective area and elevation. This enhances reliability by over 20%, improving scour depth assessment in debris-laden scenarios. This advances the understanding of debris's role in local scour, benefiting bridge design and management practices.
Abstract
Present paper shows the different types of tensor product model based linear matrix inequality controller design and feasibility analysis of two degrees of freedom aeroelastic wing section model. The tensor product models are based on reducing or removing the nonlinear behavior of the system and weighting functions. The linear matrix inequality based method results globally asymptotically stable system. The goal of the paper is to examine that selecting and varying the transformation space influences the feasibility of the linear matrix inequality based controller. The paper gives a comparison between the different tensor product models in terms of controller performance. The linear matrix inequality gives feasible solution for the controller design if the transformation space is selected adequately.
Endeavor for Self-Realization
The Story of Three Czech Professors of Architecture at the Slovak Technical University
Törekvés az önmegvalósításra
Három cseh építészprofesszor története a Szlovák Műszaki Egyetemen
This paper focuses on the reactions of three professors and architects (Jan E. Koula, Vladimír Karfík, and Alfred Piffl) to how the totalitarian political regime restricted and interfered with creative and academic freedoms in the period starting with the introduction of architectural education at the Slovak University of Technology and ending with the so-called “normalization” period in the former Czechoslovakia. All three of them were already active in interwar Czechoslovakia and thus had rich experience with working under democratic conditions, and their early work was influenced by the interwar avant-garde movements. After World War II, in part thanks to their pioneering work at the Slovak University of Technology, they got caught up in the system of the authoritarian socialist state. The central question that this study asks is how the trio dealt with the totalitarian regime, which stood in contrast with the democratic period of interwar Czechoslovakia that formed them as architects, and brought further limits to their work. Based mostly on material from their personal estates and period publications, we reveal how each of them found his own way to deal with the totalitarian regime, and we argue that even its limitations did not make Koula, Karfík, and Piffl abandon their beliefs and creative credos completely.
Az építésautomatizálás technológiai lehetőségei
Az ipar 4.0 szemlélet kibontakozása az építőiparban
The Technological Opportunities of Construction Automation
The Development of the Industry 4.0 Approach in the Construction Industry
Az építőipar a munkaerő hiánya és az egyre fokozódó minőségi elvárások miatt a hagyományos, jellemzően emberi erőforrást alkalmazó vagy emberek által közvetlenül működtetett technológiák irányából apró lépésenként az automatizált technológiák irányába fordul. Az ezzel együtt járó változás csak úgy lehet zökkenőmentes, ha az építőipar résztvevői aktív részesei a változási folyamatnak. A cikk az építőipar fejlődési irányait, annak problematikáját és lehetőségeit kívánja bemutatni a területtel kapcsolatos kutatások és a már alkalmazott technológiai megoldások elemzésével a közeljövőben lehetséges változások, további lehetőségek, illetve problémák feltérképezésére és megvilágítására törekedve.
Abstract
Integrating thermal energy storage with thermal conversion systems is necessary to maximize their use. Phase change materials are the best media for storing and releasing thermal energy from various basic material types. Because the phase change materials have a high latent heat of fusion, it is often viable to use these characteristics and include the phase change materials in building envelopes to store thermal energy. The paper provides a thorough categorization of the phase change materials and thermal energy storage systems, in addition to an evaluation of their modeling using computational fluid dynamics. The purpose was to highlight computational fluid dynamics as a useful technique for advancing the engineering of thermal energy storage devices.
Abstract
This study evaluated the thermal performance of side divergence and uniform micro-channel heat sinks by comparing and contrasting them. Heat transfer and fluid flow characteristics in these micro-channel configurations were studied using computational fluid dynamics simulations employing ANSYS Fluent 2017 code for this purpose. Laminar flow through micro-channels with a Reynolds number of 207 was the subject of the investigation. The goal is to determine how side divergence affects heat dissipation efficiency concerning traditional uniform micro-channels. The results showed that the best divergence ratio is 1.5 that achieved the highest performance. The study also revealed that side divergence micro-channel heat sinks can achieve thermal performance up to 14% higher than uniform micro-channel heat sinks.
Abstract
This article is dedicated to diagnosis of damage to air distribution in a room with twisted, compact, and flat air jets, and to searching of ways to solving the problem. It was found that in order to avoid damage to the air distribution system in rooms of different purposes and dimensions; it should be air streams of the appropriate types and with the appropriate characteristics. Parameters of a swirled, compact, flat, rectangular air jet when creating comfortable climatic conditions in the rooms of different purposes and dimensions are determined. The relationship between the angle of inclination of the rotating plates (for twisted jets), ratio of sides of the slit (for all rectangular including compact and flat streams) and a long-range of these flows is established.
Abstract
Progress in building construction requires more durable concrete with higher strength. Polymer and water reducer liquids can improve concrete strength and durability. This research aims to improve the mechanical properties of polymer-modified concrete by using anti-slip sand and silica fume to achieve more durable concrete against sulfate attack and higher mechanical properties. The study shows an increase in compressive strength from 25.7 MPa for reference mix to 45.5 MPa using 15% silica fume and 30% Anti-slip sand; tensile strength increased from 2.72 to 4.4 MPa. Flexural strength also increased, and durability to sulfate attack also increased. The study includes the increment of durability against freezing-thawing cycles for different mixes.
Abstract
Direct resistance check by applying advanced numerical models is getting increasingly used for the design of steel slender plated structures. This method has to take into account the same uncertainties as traditional analytical design calculations and should ensure the Eurocode-based prescribed safety level. The application of the model factor gives the possibility to account for the model-related uncertainties. The current study focuses on the determination of the model factor for one specific failure mode, the patch loading resistance. Numerical model has been developed and validated based on laboratory test results. To evaluate the model uncertainties, physically possible modeling differences are introduced, and their effects are evaluated on the resistance. The final aim of the study is to determine the model factor for the analyzed girder type and failure mode based on statistical evaluation.
Abstract
Warping not only one of the most important phenomena in steel section it is also considered as the most complicated phenomena. Ductility, bearing capacity and serviceability of steel sections may affect by increasing stress concentration of the normal stresses due to warping. In the present work, simulation of steel beam section under effect of warping is studied. Two cantilevers connected to two columns in opposite sides with a middle steel beam-column connection to create different moments on the beam to investigate the behavior of steel section under warping using building information modeling. It is found that the stress strain relationship has four groups depending on the load intensity and the angle of rotation induced due to warping.
Abstract
Method of numerical analysis of the influence of initial depression depth coupled with absolute surface roughness and with Manning's roughness coefficient onto the key hydraulic parameters of the stormwater runoff is proposed. Small highly urbanized catchment with 100% impervious cover was used in stormwater management model numerical simulations for climatic conditions of the Lviv City (Ukraine) at the return period of 1 year. An increase in depression depth from 1 to 5 mm causes reduction in the specific maximum peak runoff from 5.13∙10−3 L/(s∙m2) to 3.29∙10−3 L/(s∙m2), while the critical duration of rainfall increase from 17 min to 56 min. The dimensionless maximum peak flow rate is expressed as a two-parameter exponent function of the initial depression depth, allowing the estimation of the lower limit of this discharge for the practically significant range of the depression depth.
Abstract
Due to the substantial rise in wind power generation, the direct-drive permanent magnet synchronous generator has emerged as a leading technology for efficient variable speed operation, meeting grid demands effectively. This paper presents a comparative analysis of control strategies for permanent magnet synchronous generator based wind turbine using real variable wind speed data from a 2 MW of Tetouan wind farm in Morocco. The proposed approach is based on evaluating two primary control strategies: the adaptive fuzzy-proportional-integral controller and the conventional proportional-integral controller aimed at enhancing the wind turbine's output power. The simulation performed on MATLAB-Simulink indicates that pitch control mechanisms play a crucial role in optimizing power generation, also demonstrating its ability to achieve satisfactory performance.
Abstract
The structural assessment of historical buildings poses a significant challenge for engineers. However, when it comes to historical structures, more commonly used and reliable destructive testing may not always be viable. Instead, non-destructive testing has gained prominence, encompassing techniques like the Schmidt hammer test, georadar, and sonic-based tests.
In this paper, the viability of employing sonic testing on historical masonry structures was investigated. This study involves using the measured sonic velocities to identify voids and solid parts within masonry walls. In addition, the purpose is to determine the compressive strength of both mortar and brick constituents and to analyze the effects of moisture and compressive stress on the propagation velocity of waves.
Abstract
This work investigates the effect of two wall roughness types, triangular and circular, on convection and radiation heat transfer in a small space. The ANSYS Fluent is used to do thermal and dynamic modeling; the left wall is warmer than the right one. The upper and lower walls are adiabatic. The Nusselt numbers are compared in all cases and for two Rayleigh values, which change based on the cavity's characteristic length. The results show temperature contours and Nusselt curves. It was observed that the roughness had a strong effect on the air's thermal behavior inside the cavity, where the Nusselt decreased in both roughness cases, especially at small heights. However, the largest decrease is in the triangular case and for angles less than 90°. For 72°, Nusselt is 13.32 and 6% less than smooth and circular cases respectively.
Abstract
The study analyzed surface treatment's impact on mechanical properties of Fe-based amorphous coatings. Specimens underwent six-hour treatments at 670 and 770 °C using vacuum heat. Results revealed distinct mechanical features in the coating: Vickers hardness reached 755, scanning electron microscope images displayed glassy phases, showcasing good wear resistance and compressive residual stresses at around −55 MPa. A remarkable 122% increase in compressive residual stress was noted through combined vacuum heat treatment and sandblasting. Volume wear decreased from the initial 18 to 14 mm3 after treatment at 670 °C followed by sandblasting, indicating a 30% enhancement in wear resistance. Yet, using vacuum heat treatment at 770 °C negatively impacted the coating's properties.
Abstract
The paper presents a normalized, varying step size-based least mean square-based control for a standalone microgrid and Ant Lion optimization-based maximum power point tracking. This modified version of the incremental conductance algorithm addresses issues like slow dynamic response, fixed step size issues, and steady state oscillations. Comparative analysis with well-known techniques shows that Ant Lion optimizes the tracking of maximum power points more accurately, with fewer oscillations and increased efficiency. Power management and power quality are maintained through proposed adaptive voltage source converter control. The proposed voltage control shows better performance under various dynamic and steady conditions.
Abstract
The present research studies the effect of adding sugar factory waste sugarcane molasses as an alternative to chemical inhibitory additives manufactured on concrete cast during hot weather in the summer of Iraq. The current study includes a study of the setting time for cement paste and workability for fresh concrete and some mechanical properties of hardened concrete with sugarcane molasses using percentage 0–0.3% of cement weight. The study also included studying the value of pH of concrete to investigate the effect of sugarcane molasses on reinforced concrete. The results showed that the sugarcane molasses can be used by about 0.1% of cement weight for medium projects and between 0.1 and 0.2% for large projects. It was also found that the compression strength increased by about 11.5% and the indirect tensile strength increased by about 7.5 and 7.4% for splitting and flexural test, respectively for concrete mixtures containing 0.2% of sugarcane molasses.
Abstract
Helical concrete columns are a new type of structural members which arose in new twisted buildings to satisfy architectural purposes. Helical concrete columns have a unique geometry which depends on the values of twist angle (ϕ) and the tilt distance of the center of rotation. According to the ACI T1.1R-01:2001 guidelines, a combined effect of axial load and lateral cyclic displacement protocol was applied to twelve specimens. Nonlinear finite element method was used to conduct the analysis and the numerical simulation for the helical reinforced concrete columns. The findings of the study revealed that the value of the buckling load, lateral displacement and the drift angle of helical concrete columns are significantly affected by the tilting distance of the rotation center and the twist angle.
Abstract
Design flood hydrographs are often used to project safe and cost-effective hydraulic structures. This study proposes a system based on a combination of empirical and statistical approaches for constructing synthetic design flood hydrographs, that practitioners can easily apply. The system uses scaled observed seasonal flood hydrographs and respects the dependence structure among the flood peaks, volumes, and durations deduced from the set of seasonal flood hydrographs observed. The method was developed and tested based on data from the Horné Orešany reservoir in Slovakia.
Abstract
In the post-pandemic period, cities are committed to creating healthier and more healing urban environments. In high-density urban environments, urban complexes are increasingly assuming the function of enriching the external space and activating the vitality of cities, and their architecturally oriented public spaces have great potential for the promotion of residents' health. However, current research on public space and health has focused on green spaces and neighborhoods, and has not yet systematically sorted out the pathways that influence how building-oriented public space can contribute to health. In order to fill the gap, this study attempt to establish a model of health-promoting architecturally oriented public space, which can provide a reference for the similar projects.
Abstract
In the last two decades, the utilization of timber in construction has gained increasing attention among researchers and sustainable building designers. Therefore, studies of climate impact on timber structures have been conducted, many of them focusing on the moisture content caused changes in timber. In the present study, four-point bending tests have been performed on three testing groups, containing 30 samples each. The first group has been tested under its natural conditions, while the second and the third groups were fully saturated with water. The third group was glazed with a protection material. The results show the changes in the modulus of elasticity and the modulus of rupture caused by the moisture content increase. In the same time the material behavior changed from brittle to semi-ductile or ductile for some samples.
Abstract
This paper is dedicated to the memory of Dr. Miklós Iványi, who instilled in the authors an appreciation for experimental investigations, which are foundational to understanding material and structural behavior. Timber-concrete composite structures are increasingly adopted for new buildings due to their favorable sustainability parameters and the increased availability of cross laminated timber. For larger spans, however, solid timber floors lead to higher timber volumes and the use of glulam beams may become necessary for a more efficient use of wood. This paper presents laboratory tests of glulam-concrete composite beams and is the first in a series of two papers on investigating the associated failure mechanisms. Three full-scale glulam-concrete beam specimens were studied. The glulam and concrete are monolithically interconnected using a continuous layer of adhesive. Shear reinforcement was added to the glulam beams to allow for failure mode control. Static load tests to failure were conducted along with acoustic emission monitoring to track the progression of the failure. The results indicate that the shear reinforcement of the glulam layer affects the load capacity of the composite beam through shifting the failure from a shear to a tension failure mode. Similar glulam-concrete beams can enable larger span applications for buildings and bridges while maintaining an attractive sustainability performance.
Abstract
Cement and concrete are the most crucial and dominating engineering materials in the construction sector. Cement serves as an excellent binder for concrete and when it is treated under unusual conditions either to satisfy accelerating or retarding requirements by the construction industries, admixtures role comes into the effect. The construction industry has been searching for retarding admixtures and the optimal dosage level, particularly for ready mix concrete applications. Generally the retarding admixtures such as organic retarders (lignosulphonates, hydroxycarboxylic acids and their salts, phosphonates, sugars) or inorganic retarders (phosphonates, borates) were generally used to reduce the speed of the reaction between cement and water by altering the growth of the hydration products and/or limiting the rate of water penetration to the cement particles. The research was still in its infancy stage in terms of determining not just the appropriate dosage amount, but also the ideal retarder materials for the aforementioned uses. In considering this industrial need, an attempt was made on utilizing the usage of sugar in the concrete to study the retarding effect without affecting the strength properties of cement. The sugars usage levels were at 5, 10, 15, and 20% of the usage of cement to investigate consistency, setting time, compressive strength and micro structure properties at the curing age of 7, 14 and 28 days on the mortar specimens. The conclusions of the study reported that setting time was extended with increase of the dosage levels of sugar. However in considering the strength property, less than 5% of sugar dosage level can be better for the application as retarding agent in the industry applications.
Abstract
This paper presents an investigation on a battery-less voltage of Piezoelectric (PZT) V-shape cantilever beam Energy Harvester (EH) using human body vibration. The frequency ranges are walking (0–5 Hz), running (6–10 Hz) and motions (11–15 Hz) for human movement. Pacemaker devices typically require a lower resonant frequency with higher voltage which is powered by batteries. The battery has a limited duration during its working process and the battery is difficult to replace in the human body. To address the aforementioned issue, a V-shape cantilever beam EH has been developed as a solution to overcome these limitations. The cantilever beam was designed in COMSOL Multiphysics software 5.5 version using the Finite Element Analysis (FEA) method for experimental investigations followed by three categories of frequency ranges of the human body. The simulation results showed that the generated battery-less higher voltage was 269 mV (AC) at the resonant frequency of 14.37 Hz in the motion range of 11–15 Hz. Later, an Ultra Low Power (ULP) electronic circuits will be designed and simulated in the LTSPICE software to convert and boost-up from 269 mV (AC) to DC voltage attained. The estimated output power of the energy harvester system can be powered up (4.7 µW) for modern pacemaker applications.
Abstract
Aim
The occlusion of the teeth is affected due to the appearance of micro-cracks resulting from maximum stresses in the contact zones between the wire and the bracket under normal and tangential loading. The objective of this study is to evaluate the surface and volume constraints in the presence of bonding and partial sliding zones on the contact surface between wires and supports. Knowledge of these stress fields will make it possible to better limit the surfaces where most of the micro-cracks occur. Indeed, the evaluation of the stress will facilitate the modelling or application of established micro crack models on this subject, because the initiation of micro-cracks often appears on the contact surface or just below it.
Materials and methods
In this study, the two most common situations of contact between the wire and the bracket were studied; the first corresponds to the situation where the wire is positioned in the center of the support (classic friction), and the second corresponds to the situation where the inclined wire touches the ends of the supports (critical contact angle).The MATHCAD software was used to simulate the damage zones for normal loading in the two cases studied (classic friction, critical contact angle). We proposed a Hertzian loading for the first case and a linear loading for the second case. Also, the effect of the additional load during wire tightening applied by the orthodontist was studied.
Results
The charge concentration is located above the contact zone, of the order of 0.3P0 (pressure per unit of arbitrary normal length), according to Mathcad simulation results. The adhesion zone/micro-slip zone contact generates the largest tangential load, which is directed towards the side experiencing the most stress. We also observed that the stick area shifts towards the recessed side when the additional load is applied. Additionally, comparing the configurations, the critical contact angle resulted in a higher maximum shear stress.
Abstract
The dog clutch offers advantages in mass and efficiency, but faces challenges in mismatch speed synchronization, which affects its shiftability. Face impact between dog teeth also reduces its lifespan. Our previous work introduced the kinematical shiftability condition that ensures impact-free gearshift but had limitations due to analysis assumptions. This study eliminates those assumptions, but uses a similar approach. Based on our previous work for dog clutch engagement dynamics, we develop the dynamical shiftability condition. Validation with full dog clutch dynamics showed an agreement. Employing another previous work that introduced shiftability map and parametric study method, we study system parameters impact on shiftability but based on the dynamical shiftability condition.
Abstract
The Jordan Museum is the most important modern archeological museum in Jordan. This paper assesses the quality of design and the visitors' satisfaction with the Jordan Museum. Also, it investigates which of the selected performance elements contribute most to visitors' satisfaction. Investigative Post-Occupancy Evaluation (POE) was used within a mixed methodology approach. A questionnaire was used for the quantitative part, complemented by other qualitative methods. Descriptive statistics were used to determine the design quality and visitors' satisfaction. Stepwise regression was used to detect which performance elements predict overall visitors' satisfaction. The design quality of the museum was rated as good, and its permanent galleries were exceptionally rated as excellent. The visitors were generally satisfied with the museum. Visitors were satisfied with the interior and exterior finish but were not impressed with the heavy use of stone in the façade. The simplicity of the museum layout made navigation easy, and visitors were satisfied with wayfinding. This paper is the first to use POE to assess the Jordan Museum. The findings can be used to enhance the management and operation of the Jordan Museum. Also, important performance elements can be developed into guidelines to guarantee effective museum designs in the future.
Abstract
This study explores the impact of corrosion on Ground Penetrating Radar (GPR) responses through practical experiments and numerical modelling, focusing on rebar diameter reduction, corrosion product layer thickness, crack formation and corrosion product filling in vertical and transverse crack. Practical experiments involved GPR testing of reinforced concrete slab. By analyzing B-scans we identify areas with moderate and severe corrosion. Numerical modelling using the Finite Difference Time Domain (FDTD) Method to model GPR signal propagation in a concrete bridge deck with corrosion is applied. Key finding includes a significant 26.70% increase in reflected wave amplitude when corrosion product filling in vertical crack increased by 400%, highlighting its extensive effect on signal GPR propagation. Reduced rebar diameter led to a 9.79% amplitude decrease and a 0.06 ns arrival time delay. Increased corrosion product layer thickness primarily affected arrival time with a 0.06 ns extension but significantly amplified GPR signal amplitude. These findings offer insights for improving GPR based corrosion detection and assessment methods, leading to more robust systems for concrete bridge deck inspection and maintenance. This paper contributes to understanding how corrosion affects the signal that is detected by GPR. This information can be used to improve the way that we manage and assess corrosion in concrete bridge deck.
