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TBDY-2018'de Belirtilen Donatlı ve Donatısız Yığma Yapı Türlerinin Yatay Yükler Etkisi Altındaki Davranışlarının Deneysel ve Sayısal Olarak İncelenmesi
No full textYığma yapılar, özellikle Doğu Anadolu, Kuzey Anadolu ve Batı Ege fay hatları boyunca yaygın olarak kullanılan ve mevcut yapı stoğunun önemli bir bölümünü oluşturan yapılardır. Malzeme kalitesinin yetersiz olması durumunda ve inşaat tekniklerinin düzgün uygulanmamasından dolayı depreme karşı yetersiz olan bu yapılar, özellikle ekonomik nedenlerle tercih edilmekte olup, özellikle kırsal alanlar ve tarihi dokularda yoğun olarak görülmektedir. Bu nedenle, yığma yapılar üzerine yapılan araştırmalar hem mevcut riskin azaltılması hem de tarihsel ve çağdaş yapıların güvenliğinin artırılması açısından büyük önem taşımaktadır. Türkiye Bina Deprem Yönetmeliği (TBDY 2018), yığma binalar için farklı yapı türleri tanımlamaktadır. Bu çalışmada, yönetmeliğin 11. bölümünde yer alan donatılı ve donatısız yığma yapıların yatay yükler altındaki davranışları deneysel ve sayısal olarak incelenmiştir. Deneysel olarak laboratuvar ortamında 1/1 ölçekli, tek katlı, 3.2 × 3.3 × 3 m boyutlarında, tek açıklıklı donatılı ve donatısız yığma yapı numuneleri üretilmiş ve tersinir tekrarlanır yükleme etkisi altında davranışları incelenmiştir. Yükleme, maksimum yüke kadar yük kontrollü, ardından deplasman kontrollü olarak uygulanmış; her yükleme adımında elde edilen veriler bilgisayar ortamına kaydedilmiştir. Hasar durumları gözlemsel olarak değerlendirilmiş ve ilgili bölgeler işaretlenmiştir. Sayısal çalışmalar ANSYS programı ile gerçekleştirilmiş, elde edilen sonuçlar deneysel verilerle karşılaştırılmıştır. Ayrıca numunelerin üretim sürecindeki işçilik zorlukları ve maliyet farkları analiz edilmiştir. Sonuçlar, donatılı yığma yapıların donatısız yapılara kıyasla daha yüksek taşıma kapasitesi, süneklik ve enerji tüketme kabiliyetine sahip olduğunu; ancak uygulamadaki işçilik zorlukları ve maliyet artışı nedeniyle yaygın kullanımları için detaylı planlama ve mühendislik gerektirdiğini göstermiştir. Sayısal verilerin deneysel bulgularla büyük oranda örtüşmesi, çalışmanın güvenilirliğini desteklemektedir.Masonry structures are widely used along the Eastern Anatolian, North Anatolian, and Western Aegean fault zones and constitute a significant portion of the existing building stock in Turkey. Due to inadequate material quality and the improper application of construction techniques, these structures often exhibit poor seismic performance. Nevertheless, they are frequently preferred for economic reasons and are predominantly found in rural areas and historic settlements. Consequently, research on masonry structures is of vital importance for both mitigating existing seismic risks and enhancing the safety of historical and contemporary buildings. The Turkish Building Earthquake Code (TBDY 2018) defines various types of masonry structures. In this study, the seismic behavior of reinforced and unreinforced masonry buildings, as classified in Section 11 of the code, was investigated through experimental and numerical methods. Full-scale, single-story, single-bay masonry specimens measuring 3.2×3.3×3 m were constructed in a laboratory setting. These specimens were subjected to reversed cyclic loading to examine their structural response. The loading protocol involved load-controlled cycles up to the maximum load, followed by displacement-controlled cycles. Data collected at each loading stage were digitally recorded. Damage states were evaluated through visual inspection, and affected regions were marked accordingly. Numerical analyses were conducted using the ANSYS software, and the results were compared with the experimental findings. In addition, challenges encountered during the specimen fabrication process such as labor intensity and cost differences were analyzed. The results indicate that reinforced masonry structures demonstrate superior load-bearing capacity, ductility, and energy dissipation compared to unreinforced ones. However, due to increased construction complexity and costs, their widespread implementation requires comprehensive planning and engineering considerations. The strong correlation between the numerical and experimental results supports the reliability and validity of the study
Betonarme Kirişlerde Etriyeye Alternatif Olarak Kullanılması Planlanan I ve U Şekilli Donatıların Kesme Dayanımına Katkısının Deneysel Olarak Araştırılması
No full textIn this study, the feasibility of using I- and U-shaped shear reinforcements as an alternative to conventional full-anchored stirrups in reinforced concrete beams was experimentally investigated. Alternative shear reinforcements with different hook lengths and stirrup spacings were used to examine their effects on the load-carrying capacity, ductility, stiffness, and failure modes of the beams. A total of 18 reinforced concrete beam specimens were produced for the experimental study. Among these, six specimens were designated as reference specimens with conventional full-anchored stirrups, while the remaining 12 specimens featured hook lengths of 0 cm, 1.5 cm, and 3.5 cm, with stirrup spacings of 5 cm, 10 cm, and 15 cm. The beams were tested using a four-point bending test, and their load-bearing capacities, displacement values, and crack patterns were analyzed. The experimental results indicated that the specimens with 3.5 cm hook lengths exhibited the closest shear capacity performance to that of fully anchored stirrups. However, specimens with 0 cm and 1.5 cm hook lengths exhibited more sudden and brittle failures. Additionally, an increase in stirrup spacing resulted in a decrease in load-bearing capacity and led to earlier shear failures. While the alternative reinforcements were partially effective in enhancing ductility, they failed to achieve the strength level provided by conventional full-anchored stirrups. Based on the findings, it is not recommended to use I- and U-shaped reinforcements as a direct replacement for full-anchored stirrups. It has been determined that traditional stirrups should be preferred for structural elements where shear strength is critical. Future studies should conduct extended experiments with different reinforcement configurations and concrete classes to further investigate the applicability of these alternative shear reinforcement systems.Bu çalışmada, betonarme kirişlerde geleneksel tam sargılı etriyelere alternatif olarak I ve U şeklindeki kesme donatılarının kullanılabilirliği deneysel olarak araştırılmıştır. Farklı kanca boylarına ve etriye aralıklarına sahip alternatif kesme donatıları kullanılarak, bu donatıların kirişlerin taşıma kapasitesine, sünekliğine, rijitliğine ve hasar modlarına etkisi incelenmiştir. Deneysel çalışma kapsamında toplam 18 adet betonarme kiriş numunesi üretilmiştir. Bunlardan 6'sı geleneksel tam sargılı etriyelere sahip referans numuneleri olarak belirlenmiş, diğer 12 numunede ise kanca boyları 0 cm, 1.5 cm ve 3.5 cm olarak seçilmiş ve etriye aralıkları 5 cm, 10 cm ve 15 cm olarak düzenlenmiştir. Kirişler dört noktalı eğilme deneyi ile test edilmiş, yük taşıma kapasiteleri, deplasman değerleri ve çatlak desenleri analiz edilmiştir. Deney sonuçları, 3.5 cm kanca boyuna sahip etriyelerin kesme kapasitesi açısından tam sargılı etriyelerle en yakın performansı gösterdiğini, ancak kanca boyu 0 cm ve 1.5 cm olan numunelerde daha ani ve gevrek kırılmaların meydana geldiği gözlemlenmiştir. Ayrıca, etriye aralığının artmasıyla birlikte taşıma kapasitesinde düşüş gözlenmiş ve kesme hasarlarının daha erken oluştuğu belirlenmiştir. Alternatif donatıların sünekliği artırmada kısmen etkili olduğu ancak geleneksel tam sargılı etriyelerin sağladığı dayanım seviyesine ulaşamadığı görülmüştür. Elde edilen bulgular doğrultusunda, I ve U şeklindeki donatıların tam sargılı etriyeler yerine doğrudan bir alternatif olarak kullanılması önerilmemektedir. Kesme dayanımının kritik olduğu yapısal elemanlarda geleneksel etriyelerin tercih edilmesi gerektiği belirlenmiştir. Gelecekte yapılacak çalışmalar kapsamında, farklı donatı konfigürasyonları ve beton sınıflarıyla genişletilmiş deneyler yapılması önerilmektedir
Performance Investigation of Solar Air Collector with Artificially Roughened Absorber Surface
No full textSolar air collectors, which are renewable energy systems, have an important place in the fields of space heating, drying of industrial and agricultural products. In this thesis study, the performances of double-pass solar air collectors with flat plate (M1), artificial wire roughness only on the lower surface of the absorber plate perpendicular to the flow (M2) and artificial wire roughness on both the upper and lower surfaces of the absorber plate perpendicular to the flow (M3) and the effects of roughness on the performance were investigated analytically. Different model collectors were compared with each other and with the results of smooth flat plate collectors. In the analysis, Nusselt number and friction factor correlations developed by the researchers for transverse, continuous wire roughness in air collectors were used. In the study, solar radiation, air mass flow rate, Reynolds number, relative roughness height (e/Dh) and relative roughness pitch (p/e) were selected as parameters. Relative roughness pitch is considered as 10-40, relative roughness height is considered as 0.011-0.030. Analyses are carried out for solar radiation in the range of 400-1000 W/m2, mass flow rate is 0.043-0.169 kg/s, and Reynolds number is 5000-20000. In the study, energy balance equations created for collector components are solved as a result of iterations with the algorithm developed in Matlab environment. In the study, the highest thermal and thermohydraulic efficiencies are found as 0.76 and 0.64 for e/Dh=0.030 and p/e=10, respectively, in M3 collector. The maximum Nusselt number in M3 collector is 52% higher than M1.Yenilenebilir enerji sistemlerinden olan havalı güneş kollektörleri, mahal ısıtma, endüstriyel ve tarımsal ürünlerin kurutulması alanlarında önemli bir yer tutmaktadır. Bu tez çalışmasında düz plakalı (M1), yutucu plakanın sadece alt yüzeyi akışa dik şekilde yapay tel pürüzlü (M2) ve yutucu plakanın hem üst hem de alt yüzeyleri akışa dik şekilde yapay tel pürüzlü (M3) olan iki geçişli havalı güneş kollektörlerinin performansları ve pürüzlülüğün performansa etkileri analitik olarak incelenmiştir. Farklı model kollektörler birbirleri ile ve pürüzsüz düz plakalı kollektör sonuçları ile kıyaslanmıştır. Analizde araştırmacılar tarafından geliştirilen, havalı kollektörlerde enine, sürekli tel pürüzlülük için Nusselt sayısı ve sürtünme faktörü korelasyonları kullanılmıştır. Çalışmada güneş ışınımı, havanın kütle debisi, Reynolds sayısı, bağıl pürüzlülük yüksekliği (e/Dh) ve bağıl pürüzlülük aralığı (p/e) parametre olarak seçilmiştir. Bağıl pürüzlülük aralığı 10-40, bağıl pürüzlülük yüksekliği ise 0.011-0.030 arasında dikkate alınmıştır. Analizler, güneş ışınımı 400-1000 W/m2, kütle debisi 0.043-0.169 kg/s, Reynolds sayısı 5000-20000 aralıklarında gerçekleştirilmiştir. Çalışmada kollektör bileşenleri için oluşturulan enerji denge denklemleri MATLAB ortamında geliştirilen algoritma ile iterasyonlar sonucunda çözümlenmiştir. Çalışmada en yüksek ısıl ve termohidrolik verim M3 kollektörde, e/Dh=0.030 ve p/e=10 için sırası ile 0.76 ve 0.64 bulunmuştur. M3 kollektörde en büyük Nusselt sayısı ise M1'e göre % 52 daha fazladır
Airborne Gravity Data Reconstruction Strategies for Geoid Optimization in Peninsular Malaysia
No full textGeoid height is essential for precise height determination, particularly in surveying and geodetic applications. Airborne gravity data substantially improve geoid models, especially over regions with complex terrain where terrestrial coverage is limited. However, since airborne data are acquired at flight altitude, they require downward continuation to the geoid surface which an inherently unstable process. Despite ongoing advancements, the most effective strategy for combining and gridding gravity data, particularly airborne measurements, remains a topic of research. This study evaluates two downward continuation strategies to assess their influence on geoid accuracy. The first strategy applies downward continuation to airborne data simultaneously with terrestrial and marine data, incorporating a range of buffer distances (0 km, 1 km, 5 km, and 10 km) to examine their effect on model performance. The second strategy involves performing downward continuation on airborne data independently before merging with other datasets. Numerical results indicate the Root Mean Square Error (RMSE) values of 0.044 m for the first strategy and 0.045 m for the second, with a marginal difference of 0.001 m. Although the difference appears minor, even marginal improvements can be pivotal in high-precision geoid modelling particularly in localized regions where complex topography or sparse data coverage may magnify subtle errors. Such refinements are essential to advancing the long-term goal of achieving geoid accuracy at the 1 cm level for Peninsular Malaysia. © Geoinformatics International.DSMM; Peninsular Malaysi
Urban Growth Predictions: Optimization of Urbanization Strategy for Risk Mitigation in Medium-Sized Cities
No full textThe study aims to forecast future urban growth and comprehend potential risks, with a particular focus on the dynamic nature of urban growth in medium-sized cities. By identifying factors affecting growth in urban areas, the SLEUTH model was utilized to analyze patterns of urban growth and associated changes in land use. Four scenarios were developed to anticipate urban development in Osmaniye, a medium-sized Turkish city, using the SLEUTH model for the year 2039. Scenarios S.1 and S.4 focus on the impacts of public investment on urban growth, while S.2 and S.3 examine the effects of urbanization on rural areas. Scenario S.3 also explores diverting urban development from high-risk seismic zones. S.1 poses the highest risk to agriculture (51% urbanization), while S.3 is the least threatening (37%). For forests, S.2 presents the highest risk (31%), but S.3 is the safest (25%). Overall, Scenario 3 provides the most effective approach for urbanization strategy, particularly for rural areas, protecting them from urbanization pressures and preserving geologically hazardous locations in Osmaniye. The study highlights how the SLEUTH model demonstrates the interaction between urban growth and spatial limitations, emphasizing the importance of understanding the consequences of urban growth for implementing effective zoning regulations
Dewatering of Chromite Ore Plant Tailings Using Carboxymethyl Cellulose and Chitosan as Flocculants
No full textFine particle size mine tailings are turned into large particles by flocculation as a method of separating solids from liquids. Without solid-liquid separation, water required for plant operations cannot be recovered, which would necessitate the construction of a larger tailings dam. In this study, flocculation experiments were performed using carboxymethyl cellulose (CMC) and chitosan to find the optimum sedimentation conditions of tailings. Therefore, flocculation was optimized by applying response surface methodology (RSM). A 34 full factorial central composite design (CCD) was selected to describe the effect and interaction of four variables: flocculant dosage, stirring speed, pulp density, and pH. The performance of the flocculants was evaluated by measuring the turbidity of the suspension, water recovery, and sludge compactness. The optimum turbidity values obtained with CMC and chitosan were 6.80 nephelometric turbidity units (NTU) and 8.20 NTU, respectively. CMC and chitosan both contributed significantly to the flocculation of tailing, and flocculation was highly dependent on the pH and pulp density. The positively charged particles in the sample flocculated because of electrostatic interactions when CMC was added, whereas flocculation occurred via a bridging mechanism with chitosan. The important results highlighted that both CMC and chitosan rapidly flocculated the tailings and significantly reduced the turbidity
A Machine Learning-Based Modeling Approach for Dye Removal Using Modified Natural Adsorbents
No full textThis study used machine learning models to investigate the potential of biosorbents derived from natural fruit seed waste (apricot, almond, and walnut) for removing a cationic dye. Levulinic acid (LA)-modified powders of almond shell (ASh), apricot kernel shell (APKSh), and walnut shell (WSh) were used to remove methylene blue (MB) from an aqueous solution, producing 105 experimental data points under various circumstances. Attributes included pH (3-5), adsorbent dose (0.4-6.0 g/L), concentration (10-500 mg/L), time (30-600 min), and temperature (25-55 degrees C). Species information was incorporated into the data set using the One-Hot Encoding method. The data were normalized using the min-max method, and due to the non-normal distribution of the data, Spearman correlation analysis was employed to rank the importance of the attributes. Gradient Boosting (GB), Multilayer Perceptron (MLP), XGBoost (XGB), and Random Forest (RF) algorithms were applied for regression estimation. Based on 5-fold cross-validation results, the GB model achieved the highest performance, with R2 values of 0.8858 for removal percentage and 0.9532 for adsorption capacity
A Human-Centric Evaluation of Robotic Solutions in Production and Intralogistics
No full textInternational Federation of Automatic Control (IFAC) - Management and Control in Manufacturing and Logistics, TC 5.2.; International Federation of Automatic Control (IFAC) - TC 1.3. Discrete Event and Hybrid Systems; International Federation of Automatic Control (IFAC) - TC 3.2. Computational Intelligence in Control; International Federation of Automatic Control (IFAC) - TC 5.1. Manufacturing Plant Control; International Federation of Automatic Control (IFAC) - TC 7.4. Transportation SystemsAs robotics continue to revolutionize production and intralogistics, there is a growing need to focus on human-centric approaches aligned with Industry 5.0 to ensure the well-being of workers. This paper presents an evaluation framework for robotic solutions in these settings, emphasizing the importance of human-robot interaction (HRI). By considering a human-centric approach, the study aims to guide organizations in evaluating human-robotic systems that prioritize well-being- including physical, cognitive, and psychosocial aspects - and complement rather than replacing human workers. The research categorizes robotic solutions based on their mobility and interactivity. While insightful, the framework has limitations, such as not fully capturing complex real-world scenarios and is non-exhaustive. The results highlight the positive impacts of HRI on human well-being while also addressing the potential challenges. The proposed evaluation framework provides a practical tool for decision-makers, helping them navigate the complexities of HRI towards human-centric industrial workplaces. This research contributes to the growing body of literature on human-centric robotics, offering valuable insights into the focus on human well-being in industrial settings. © 2025 Elsevier B.V., All rights reserved
Research on Maximizing System Profit in Pumped Storage Hydroelectric Power Plants
No full textRenewable Energy Sources (RES) cannot produce continuous energy. Therefore, there must be loads that can consume the energy produced at the same time. The energy produced can be wasted if not consumed. To prevent this, energy storage systems have been developed to store unusable energy and use it later when needed. These systems facilitate the storage of energy produced during off-peak hours for utilization during peak demand periods, ensuring a consistent and reliable energy supply. This study aims to maximize the system profit in Pumped Storage Hydroelectric Power Plants (PSHPs), which is one of the oldest known and highest-capacity energy storage methods. For this purpose, scenarios are considered assuming that the energy required for the pump is met from various sources at different rates. In the first scenario, it is assumed that the pump station providing water transfer will be powered 100% from RES during the day, and at night, it will receive 75% from the grid and 25% from the wind power plant. In the second scenario, it is emphasized that the energy of the pump station will be supplied from RES during the day and completely from the grid at night. Finally, in the third scenario, it is assumed that 50% of the energy supplied to the pumping station during the day comes from the grid, while the remaining 50% is sourced from RES. Energy arbitrage is utilized in all three scenarios. As a result of the study, it is seen that the energy of the pumping stations used for water transfer is supplied from RES as much as possible, so that the grid is not overloaded, and this increases the profit obtained from the system. © 2025 Elsevier B.V., All rights reserved