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
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.
Abstract
This research paper exhibits the design of a V-shaped cantilever beam as a micro Energy Harvester (EH) having Piezoelectric (PZT) as its energy source for biomedical applications. PZT source based materials have the ability to convert the mechanical energy into electrical energy. Low-power biomedical devices mostly operate using electrical energy (i.e. batteries). But batteries are treated as a bio-hazard due to the massive use of biomedical applications. To overcome this toxic bio-hazard, the proposed PZT based V-shaped cantilever beam of micro EH can solve the limitations. To perform the experimental work, the cantilever beam design parameters - length, width and thickness have been considered and simulated using COMSOL Multiphysics to get the resonant frequency of 156.19 Hz which is lower than previous research work. It was observed that the obtained lower resonant frequency can be converted into AC voltage (mV) using PZT material. To convert the output AC voltage (mV) into DC voltage, a circuit of an Ultra-Low-Power (ULP) EH will be designed in LTSPICE software. Finally, the integration of the both V-shape cantilever beam and the ULP EH circuit will be implemented in PCB hardware to generate the output power (10 µW), will be stored in super-capacitor for biomedical devices-pacemaker.
Abstract
Side friction refers to combined variables indicating the degree of interaction between the activities and the traffic stream. The condition worsens when the transport demand and road-side activities increase, leading to inefficient traffic performance. This study has been focused on evaluating side friction impacts in terms of capacity and speed. Four links divided and undivided streets in Al-Najaf City, Iraq, were selected and on-street parking, pedestrian activities, entry-exit maneuvers, and temporary parking vehicles are considered as side friction elements. The results show about a 47% reduction in speed and about a 49% reduction in the capacity at a very high side friction level. Finally, a speed-predicting model has been developed for predicting the speed under side friction impacts.
Abstract
The multi-aquifer system of the Nubian aquifer in central Sudan hydrogeological system was simulated using a three-dimensional steady-state model. The goal of the study is to detect the effect of pumping on the groundwater flow and thus, the aquifer productivity. The conceptual model of the study area was built based on the available geological and hydrogeological data guided by geophysical survey. Processing MODFLOW numerical code was used to calculate the hydraulic head and water balance under the existing boundary conditions. The model accurately simulated the hydraulic head with a determination coefficient of 0.88. The calibrated model indicated that the change in storage is 0.56 m3/day indicating the study area constitutes highly productive zone and is recommended for groundwater developments.
Abstract
Real-time deformation measurements have the potential to be used in a wide range of civil and structural engineering applications. This paper introduces an algorithm that utilizes time-based photogrammetry to measure deformations in real-time. The hardware used in the algorithm consists of a camera and a computer that runs camera-control software and a MATLAB code. The code is responsible for detecting the approximate locations of the circular targets using normalized 2D cross-correlation and performing the sub-pixel measurement of the center by fitting an ellipse on the edges of the circular target. During an experimental load test of a concrete slab outfitted with Ringed Automated Detection targets, a series of images were taken at different loads. The coordinates of the targets were measured using the edge-ellipse operator, least-squares matching, and digital image correlation methods. The edge-ellipse operator has proven to be an effective method of measuring the image coordinates of circular targets.
Abstract
An experimental study was carried out on geo-polymer and reinforced concrete beams to evaluate the flexural behavior of the beams for the structural grade of M30 concrete. The results show that the geo-polymer concrete beams exhibit similar flexural strength when compared to reinforced concrete beams. The split tensile strength, stiffness characters, the energy capacity and ductility relationship were also found with satisfactory results. The deflection and the stiffness degradation at the salient stages were found to be similar and thus the geo-polymer concrete beams find a good alternative to reinforced concrete beams under flexural behavior.
Abstract
Recent studies showed a significant peak of the salt contamination in the Tisza River that exceeded ten times over the average level. The document summarizes the works performed on the investigation of ground displacement using multi-temporal satellite radar interferometry technique in Solotvyno mine located in Tiachiv region. Multi-temporal InSAR aims to identify coherent radar targets exhibiting high phase stability over the entire observation period and derives point data with locations corresponding mainly to the point-wise, man-made features. The middle area with no persecuted targets may correspond to the substantial physical changes of the surface caused by activities like mining or tunneling, adding, or removing structures or their components, and motion perceptible in one pixel.
Abstract
This project is the design of the tourism service station in the coastal park, which not only meets the basic functional requirements of the park service station but also reconfigures the station space with the regional cultural characteristics of Qingdao. The design process is mainly conceived in five aspects: locality, landscape, identity, symbolization, and diversification. It integrates the cultural characteristics of Qingdao coastal tourism with the park landscape to create a tourist rest space with diversified experiences. The purpose of this paper is to explore the interface between the stations' design and the various links of the cultural tourism industry chain. The project will be created as the “Window of Qingdao” in Baisha River Park.
Abstract
The digital economy is increasingly seen as an essential cornerstone in developing national strategies and industrial policies to enhance national competitiveness. On the other hand, a realistic assessment of digital readiness is essential for developing appropriate policies. In our paper, we group the countries of the European Union (EU) using three different methods applied to a dataset consisting of the four main dimensions of the EU's Digital Economy and Society Index (DESI) in order to identify Europe's main geographical “fault lines” in terms of digital readiness. DESI is a composite index aggregating several digitalization-related indicators to benchmark the progress of digital transformation in each member state. However, our methods aim not to rank countries but to identify groups of countries that are close to each other. The three methods used in the paper are partially ordered sets (poset), Tiered Data Envelopment Analysis (TDEA), and cluster analysis, known from multivariate statistics. The three types of clustering show a high degree of similarity, indicating the robustness of the results. Another research question relates to the extent to which the digital development of the EU Member States corresponds to the economic development of the countries and core–periphery relationships. While we can observe a high degree of similarity between the more and less developed clusters in terms of digital readiness and the groups that can be identified in terms of economic development and institutional quality, we also notice some peculiar exceptions (which could provide examples of best practices).
Abstract
In the event of a flammable liquid, gas, or vapor release the first step is to identify the type of outflow, which can fall into two categories sonic or subsonic. The two types of outflows carry different flow characteristics, which effect on the extent of the potentially explosive areas. In case of subsonic outflow, a short jet is formed without turbulent flow conditions at low velocity, which appears more concentrated around the source of release. With sonic outflow, a high velocity jet is formed with turbulent flow properties, which can extend further away from the source of release. The simulations examine the lower explosion limit of the flammable medium around the vessel where LEL20% or LEL40%. In addition, high temperature methane gas release was also presented.
Abstract
This study aims to identify and establish the long-term fluctuation of the low flow in the Hornád River. Hydrological data of five stations was obtained from the Slovak Hydro-Meteorological Institute and used for the analysis aims to show the trends of low flow and variability of the outflow during the period from 1973 to 2020. To determine low water levels, the limit value of the flow corresponding to the 70% and 90% from the flow duration curve along with the higher ones, determined on the basis of daily values for the entire multiannual period, was used. The observed patterns of low-flow changes on the example of a mountain river can be a reference point for many different studies and model simulations for other rivers in Slovakia.
Abstract
This article is related to investigations of the capture hoods of the local exhaust ventilation. The purpose of the research: to increase the zone of action of local exhaust hoods and reduce the amount of air removed. It is equipped with two barriers for air: ring and cylindrical. The empirical dependences for air velocity determination near the suction zone are obtained. Graphs, chart and three-dimensional image visualizations of removed air jet velocity near capture hood with barriers for air are designed. The reduction of production energy consumption, material, and ventilation system maintenance costs due to the correction of the design of the capture hood are the main benefits of the new solution.
Abstract
There is currently no accurate calculation procedure for determining the lateral-torsional buckling resistance of trapezoidally corrugated web girders. Therefore, a detailed investigation is performed in the frame of an experimental and numerical research program at the Department of Structural Engineering of the Budapest University of Technology and Economics. Based on the previous experimental results, a numerical model is developed to be used to determine the lateral-torsional buckling resistance by using deterministic method. The effect of flange size, corrugation geometry and boundary conditions are investigated. An improved design method is developed for the determination of the lateral-torsional buckling resistance of trapezoidally corrugated web girders.
Abstract
Analyzing the capacity of a signalized circular intersection is an essential aspect of traffic flow management. With the increased number of vehicles at the intersection, it is preferable to examine ways to increase capacity without altering the existing geometric features. A signalized circular intersection on the national highway in Győr, Hungary, between 47° 40′ 43.7988″ N and 17° 39′ 37.6668″ E is chosen and analyzed for capacity enhancement. The survey is conducted using 360-degree cameras. The PTV Vissim software is then used to construct a model based on the current and projected vehicle counts, as well as the current and proposed options. The result shows that it is possible to increase the capacity of signalized circular intersections without altering the geometric features.
Abstract
The current work discusses optimizing the structural design of reinforced high strength concrete rectangular sections under design loads. Using a least-cost design criterion and minimal design variables, an analytical approach to the problem is devised. A nonlinear mathematical programming format for the formulation of the problem is among the things that are demonstrated. To demonstrate how the formulation can be used in line with the ACI 318-08 standard, several typical cases are given. The outcomes are compared to those obtained from existing design practice. The ideal solution demonstrates unequivocally that significant reductions in the anticipated absolute costs of the building materials to be employed are possible and without making significant changes, this method may be expanded to address other portions.
Abstract
This study evaluates future changes in M-day minimum and maximum discharges in selected river basins of Slovakia, which have been divided into four groups, i.e., western, central, northern, and eastern Slovakia. Four types of data were available for the analysis, i.e., observed mean daily discharges, modeled mean daily discharges using the rainfall-runoff model, and simulated mean daily discharges according to the climate scenarios. The Indicators of Hydrological Alteration program was used to estimate the M-day discharges.
The results revealed an increase in the M-day minimum discharges in northern Slovakia. Eastern and Western Slovakia show a decrease in M-day minimum discharges and an increase in m-daily maximum discharges by 2100.
Abstract
Under the background of modernization, the continuation and development of historical and artistic values of ancient villages are faced with many difficulties, and corresponding theories are needed to guide practice. Taking Baojing Village in China as an example, this paper studies and expounds on the strategies for the protection and development of ancient villages, establishes a coordination mechanism for all parties and provides experience for the difficulties faced by this field. In the past, most Chinese ancient village literature studies focused on the characteristic value, formation, and evolution of historical and cultural villages. However, the research on the integration and utilization of resources in historical and cultural villages still needs to be further deepened.
Abstract
This paper deals with life cycle analysis of three wooden houses in terms of environmental impact indicators, construction, and operational costs. At the same time, indoor environmental quality of the houses is investigated. From the results achieved, it can be concluded that wooden house 3 shows the lowest emissions of CO2e/m2.year compared to other houses. Based on overall investigation wooden house 1 is the most advantageous. Concrete structures and mineral wool have the highest share of global warming potential. On the contrary wooden house 3 has the largest life cycle costs. Results of indoor environmental quality show that the permissible limits of the measured physical and chemical factors are not exceeded during the measurement.
Abstract
Due to significant industrialization, many countries have adopted the practice of industrial symbiosis, which involves utilizing the waste produced by one industry as a resource for another industry. The utilization of spent foundry sand (SFS), which is derived from the metal casting industry, poses a significant risk to both the environment and living organisms as a result of the existence of inorganic and organic substances. Nevertheless, this waste material can serve as a valuable resource for the construction sector. The utilization of SFS is significantly restricted due to insufficient comprehension of its concrete performance, despite its extensive range of applications. It is imperative to comprehend the behavior of spent foundry sand in concrete, particularly in relation to achieving a structure that is both strength-efficient and durable. The current study explores the usability of M-sand and spent foundry sand in self-compacting concrete. Reference concrete was produced by replacing river sand with 100% M-sand. M-sand was substituted with spent foundry sand in ratios ranging from 0 to 30%. Compared to the reference mix, SCC's mechanical and durability properties with 20% SFS were better. In comparison to the reference mix, SCC containing 20% SFS had higher mechanical and durability characteristics at 3, 7, 28 days, and 28 days, respectively. With 20% SFS, replacement showed better mechanical properties at all curing ages and better durability performance at 28 days of the curing period.
Abstract
The driver's eye height from the ground, as what drivers can see on the road, is essential for their safety and for avoiding road hazards. Using the statistical analysis of vehicles sample, the statistical parameters of the measured set of values were determined. A one-sample t-test was done to check whether the measured sample differs from the driver's eye height value specified in the Hungarian design guidelines. A new range of driver's eye height has been found, which is considered an update to the current value and might be applied in the upcoming road design. Parallel with the eye-height analysis, sight distances at vertical crest curves were modeled by AutoCAD Civil 3D. The minimum radiuses of the crest curves were defined for human eye height and for sensors of autonomous vehicles.
