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Growth Performance and Economic Analysis of Swamp Eel (Monopterus cuchia): An Application of Cobb-Douglas Production Function
No full textThis study was designed to highlight the culture techniques and socio-economic conditions of cuchia farmers. The study used primary data collected from Adamdighi upazila in Bogura district of Bangladesh for a period of 120 days from 05 March to 26 June 2016. Three different experimental treatments were used. For sociodemographic factors, two-stage stratified sampling design was used in this study. The target population was Cuchia farmers. So, a total of 90 Cuchia farmers were finally selected for analysis. One way ANOVA with multiple comparison test was applied to identify significant treatments. Cobb-Douglass production function was used to determine the contribution of the most important variables in the production process of Cuchia farming. Analysis showed that, more than 80 percent of Cuchia fish survived with fish fry and snail meat feed. All the mean differences were statistically significant to compare Cuchia meals between two periods of time. For both cases weight and height, the result showed that vermi meals were significantly different from dried fish, while fish fry and dried fish were also significantly different. The estimated result showed that a significant negative association was found between cost of fish fry feed and gross income of Cuchia farming. The cost of seed also showed a negative association. In the contrary, this study found positive and significant association in cost of Dried fish, cost of human labor. It is well known fact that Cuchia contain higher amount of nutritious value which is important for human health. Therefore, policymakers should pay special attention to this sector
Hybrid Use of Externally Embedded FRP Reinforcement for Seismic Retrofitting of Substandard RC Columns
No full textThis paper discussed the effectiveness of the hybrid use of fiber-reinforced polymer (FRP) reinforcement for the seismic retrofitting of substandard reinforced concrete (RC) columns. Four columns, except for the reference, were retrofitted with externally embedded FRP (EE-FRP) bars in a longitudinal and external FRP jacket in the transverse directions. The test parameter was the configuration of the FRP bars that were used for retrofitting along the longitudinal direction (e.g., single or hybrid use of different types of FRP bars, such as aramid (AFRP), glass (GFRP), or carbon fiber-reinforced polymers (CFRP). The test results indicated that a significant enhancement in the lateral load capacity (<= 198% in the unstrengthened column) could be achieved through the hybrid use of FRP bars under reversed cyclic lateral displacement and a constant axial load without a significant sacrifice in deformability. In addition, the test results yielded insights into the strain (e) capacities of longitudinal FRP bars in tension and their contribution to compression resistance under reversed cyclic lateral loading conditions. In addition, an analytical study was conducted to predict the cyclic flexural behavior in substandard RC columns that were retrofitted through the single or hybrid use of EE-FRP bars that considered the debonding behavior of longitudinal CFRP bars with a smooth surface.ITU Scientific Research Department [326024]; Master Builders Solutions; OTS Engineering Company; Structural and Earthquake Engineering Laboratory of Istanbul Technical University; Building Materials Laboratory of Istanbul Technical UniversityThe financial support of the ITU Scientific Research Department (Scientific Research Project No:326024), Master Builders Solutions, OTS Engineering Company, and the assistance of the staff of the Structural and Earthquake Engineering Laboratory and Building Materials Laboratory of Istanbul Technical University are gratefully acknowledged. The authors are also thankful for the support of MSc. A. Uzunhasanoglu
The impacts of atmospheric icing on performance and behavior of a controlled large-scale wind turbine
No full textIcing degrades turbine performance by altering the geometry of blade airfoils, reducing turbine power output, and increasing structural loads. In this study, the impacts of atmospheric icing on the full performance and behavior of a controlled large-scale wind turbine are thoroughly investigated. Using the Mustafa Sahin bladed wind turbine simulation model, the National Renewable Energy Laboratory 5 MW turbine is simulated with and without iced blades. The turbine blades are considered fully covered by light icing at the leading edge, which causes a reduction of up to 9.27% in Cl and an increase of up to 48% in Cd data of blade airfoils. Turbine static performance and behavior are examined at different uniform winds between cut-in and cut-out wind speeds, while the dynamic performance and behavior are estimated under turbulent winds at below (region II) and above (region III) rated regions. Simulation results are presented in terms of various turbine parameters, such as rotor power, thrust, their coefficients, blade pitch angle, rotor speed, etc. Results show that such light icing alters the turbine's aerodynamic characteristics and dynamics, increasing the turbine's cut-in and rated wind speeds, and reducing the thrust and maximum power coefficients by 5.5% and 13.35%, respectively. Under the same uniform winds, due to icing, turbine static performance and behavior are drastically disrupted in below rated region, resulting in reduced rotor speed, turbine efficiency, thrust, and power output by up to 4.77%, 39.7%, 7.63%, and 40%, respectively. In region III, however, thrust increases by up to 15% although the power output, rotor speed, and turbine efficiency do not change considerably. When the dynamic responses are examined under turbulent wind with a mean of 7.9 m/s in region II, mean power and fluctuations reduce by 14.17% and 10.88%, respectively. The mean thrust decreases by 6.86%, while its fluctuations reduce by 11.33%. The mean rotor speed reduces by 3.83%, and its fluctuations decrease by 12.84%. Under turbulent wind with a mean of 15.7 m/s in region III, the mean power and fluctuations decrease by 0.053% and 1.95%, respectively. The mean thrust increases by 11.99% and its fluctuations drop by 0.84%. The mean rotor speed does not change much, but its fluctuations increase by 0.132%. The mean blade pitch angle reduces by 9.39%, while its fluctuations increase by 7.39%
Design and Analysis of a High-Efficiency Resonant Converter for EV Battery Charger
No full textThe interest in electric vehicle (EVs) components such as battery, battery chargers, and battery management systems is increasing in parallel with the spread of electric vehicles. One of the most critical of these components is battery chargers. Battery chargers are equipped with DC-DC converters with high efficiency, low cost, and wide output voltage range. In order to provide reliable operation of the battery charger, it is of great importance that the DC-DC converters are operated with a robust and stable controller as well as designed optimally. In this paper, a design method for a CLLC resonant converter-based bidirectional dc-dc converter (BiDC) is presented for a battery charger. The resonant converter, whose design details are presented, suggests a resonant system to be used in battery chargers with fewer components than the CLLLC converter, and similar voltage gain characteristics for bidirectional power flow operations compared to the LLC converter. The design procedure highlights performing the soft switching operation and determining the resonant tank parameters. In addition, the forward mode and reverse mode gain equations required for the system to operate in the desired output voltage range have been presented. The design procedures have been validated with a CLLC BiDC model with ratings of 1 kW, 400 V input / 300-450 V output in the PSIM environment. The performance results reveal that the zero voltage switching (ZVS) has been performed for primary-side MOSFETs under a wide load range
Reliable prediction of thermophysical properties of nanofluids for enhanced heat transfer in process industry: a perspective on bridging the gap between experiments, CFD and machine learning
No full textIn recent years, traditional fluids are frequently being replaced by efficient heat transfer fluids showing physical and thermal stability. One such category of fluids is called nanofluids, in which solid nanoparticles (metals or their oxides, nitrides and so on) are suspended in a base fluid resulting in enhanced heat transfer characteristics. These nanofluids are increasingly used in low to medium temperature applications toward intensification of process and power plants by reducing the overall size and heat losses. However, as compared to a pure fluid, prediction of thermal and physical properties of nanofluids is a challenge due to unavailability of a general model. These thermal and hydraulic characteristics are strongly dependent upon multiple factor including particle size, particle volume concentration, particle composition, particle shape, temperature, base fluid material, pH and shear rate. Keeping these challenges in mind and availability of modeling tools, we first summarize and comment on popular correlations available to predict thermal and physical properties of nanofluids. Then, a general approach for carrying out reliable computational fluid dynamics (CFD) simulations is presented. The limitation of a general correlation of physical properties for input into CFD code can be overcome by use of machine learning (ML) tools such as artificial neural networks (ANN) taking advantage of the huge databank of physical properties of nanofluids. The use of ML to compliment CFD for accurate and reliable simulation of systems employing nanofluids as working fluids is highlighted at the end as potential emerging areas of research. [GRAPHICS] .Pakistan Institute of Engineering and Applied Sciences (PIEAS); Adana Alparslan Turkes Science and Technology University (ATU); Higher Education Commission (HEC) of Pakistan; [520-141007-2EG6-07]The first, third and fifth authors acknowledge the support they received from Pakistan Institute of Engineering and Applied Sciences (PIEAS). The second and the fourth authors acknowledge the support they received from Adana Alparslan Turkes Science and Technology University (ATU). Mr. Rehan Zubair Khalid acknowledges the fellowship (520-141007-2EG6-07) he received from Higher Education Commission (HEC) of Pakistan for his PhD studies at PIEAS
A NEW TYPE OF WARFARE: Chemical Filling Facilities in Istanbul, 1914–1918
No full textIn the total war era, states committed their scientific research to rapidly changing warfare conditions, making the management of war the primary goal of contemporary states. The weakness of primary weapons in neutralising the enemy (or enemies) was obvious from the beginning of the First World War. Constantly changing war strategies, integration of civilians into warfare, and the growing sense of impotence as the war proceeded longer than expected, prompted a return to the components of violence. Although research into the use of different chemicals, gases, and suffocating substances in weapons was not something new, its successful employment climaxed during the First World War. This study provides an analysis of the employment of chemical weapons during the First World War and revisits the scarce arguments on whether the Ottomans had taken part in producing chemical weapons. The primary focus here is the gas-filling facilities established in Istanbul under the supervision of German efforts for military purposes. Additionally, the unanticipated extraordinary effects of the use of chemical weapons, the strategies employed to cause attrition in trenches, and its effects on the Ottoman army are within the scope of this article. © 2023, International Committee for the History of Technology. All rights reserved
Binary Anarchic Society Optimization for Feature Selection
No full textDatasets comprise a collection of features; however, not all of these features may be necessary. Feature selection is the process of identifying the most relevant features while eliminating redundant or irrelevant ones. To be effective, feature selection should improve classification performance while reducing the number of features. Existing algorithms can be adapted and modified into feature selectors. In this study, we introduce the implementation of the Anarchic Society Optimization algorithm, a human-inspired algorithm, as a feature selector. This is the first study that utilizes the binary version of the algorithm for feature selection. The proposed Binary Anarchic Society Algorithm is evaluated on nine datasets and compared to three known algorithms: Binary Genetic Algorithm, Binary Particle Swarm Optimization, and Binary Gray Wolf Optimization. Additionally, four traditional feature selection techniques (Info Gain, Gain Ratio, Chi-square, and ReliefF) are incorporated for performance comparison. Our experiments highlight the competitive nature of the proposed method, suggesting its potential as a valuable addition to existing feature selection techniques
Optimization of complex coacervation parameters for the production of encapsulated black garlic using response surface methodology
No full textThe purpose of this study was to optimize black garlic encapsulation parameters (core/coating ratio, extract concentration, and coacervate/maltodextrin [MD] ratio) using central composite design of the response surface methodology based on encapsulation efficiency (EE) (%). The optimum parameters were determined as 4.0 for the coating material/core ratio, 50% for the extract concentration, and 6.0 for the MD/coacervate ratio depending on the EE (%). The antioxidant activity values were determined as 101 and 134 mu mol Trolox/100 g dry weight (DW) for the 2,2-diphenyl-1-picrylhydrazyl and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods, respectively, whereas the total phenolic content was 49 mg gallic acid equivalent/100 g DW for the encapsulated black garlic samples. S-Allyl-L-cysteine (SAC), gamma-L-glutamyl-SAC (GSAC), gamma-L-glutamyl-(S)-trans-1-propenyl-L-cysteine, and allicin were the organosulfur (OS) compounds determined in the samples. The SAC concentration of the encapsulated black garlic samples was determined as 22.36 mg/g, whereas the GSAC content was found at a lower concentration (0.33 mg/g) compared to SAC. The allicin content was quantified to be 0.31 mg/g. The encapsulated samples were also characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The FT-IR analysis revealed specific functional groups, including hydroxyl, carbonyl, and glycosidic linkage. The interaction between lentil protein isolate and pectin was strong enough to encourage capsule formation as visualized in the SEM images. This study shows the potential of black garlic coacervates as a functional ingredient for the food industry due to their stability, solubility, and preservation of OS and antioxidant compounds.Scientific and Technological Research Council of Turkiye (TUBITAK) [TOVAG 219O174]Scientific and Technological Research Council of Turkiye (TUBITAK),Grant/Award Number: TOVAG 219O17
Mimarlık Eğitiminde Yapı: “Yapı Teknolojisi ve Bilimi I” Dersinin Analizi
No full textTürkiye’de mimarlık eğitimi, teorik, uygulamalı ve seçmeli dersler olmak üzere üç ana gruptan oluşmaktadır. Mimari tasarım dersleri mimarlık programında önemli yer teşkil ederken, ikinci grupta tasarım derslerini destekleyen yapı dersleri yer almaktadır. Yapı dersleri, öğrencinin yapı, yapım sistemleri, yapı bileşenleri ve yapı elemanlarını öğrenebildiği bir eğitim sürecini içermektedir. Bu eğitim süreci, her öğrencinin eğitmenler tarafından verilen totaliter bilgi aktarımı ile iki ve üç boyutlu uygulamaları ürettiği kapsamlı bir uygulamalı derstir. Bir yapı dersinin çıktısı, ders kapsamındaki süreklilik ve verilen uygulamaların ısrarlı tekrarı ile bina yapım bilgisinin öğrenilmesidir. Bu çalışma, İzmir Yüksek Teknoloji Enstitüsü Mimarlık Bölümü’nde 1. Sınıf düzeyinde verilmekte olan Yapı Teknolojisi ve Bilimi I dersinin sürecini inceleyerek 2021 yılındaki öğrenci verileri üzerinden çizim ve maket performansını mimari yapı eğitimi bağlamında incelemeyi ve değerlendirmeyi amaçlamaktadır. Bu çalışmada öğrencilerin aldıkları notlar istatiksel olarak incelenmiş olup, bu sürecin belirlenen kriterler bazında değerlendirmesi yapılmıştır
Fiziksel Çevre Denetimi Bağlamında Karşılaştırmalı Bir Yapısal Sistem Analizi: Geleneksel Antakya Evleri Örneği
No full textGünümüzde geleneksel konutlar ekonomik, kültürel ve mimari açıdan tehdit altındadır. Geleneksel konutların, zaman içerisinde yaşanan depremler, afetler ve iklim şartları gibi çevresel koşullara bağlı olarak zamanla genel karakteristik özelliklerini kaybetmesi, koruma tüzükleri kapsamında planlamalarının yapılamayıp, standart ve yönetmeliklere uygun davranılmaması gibi durumlar bu yapıların korunamayıp, günden güne yok olmasına sebep olmaktadır. Bu çalışmanın amacı, Antakya ilinde bulunan geleneksel konutların mevcut hasar tespit analizlerinin yapılması ve elde edilen veriler sonucunda koruma tüzüklerine bağlı kalarak fiziksel çevre denetiminin ve sürdürülebilirliğinin sağlanması için öneriler sunmaktır. Çalışma Antakya kenti, 3.derece kentsel sit alanı bölgesinde bulunan Kurtuluş Caddesi’ndeki iki geleneksel konut özelinde gerçekleştirilmiştir. Sonuç olarak bu çalışma, çevresel etkilerin yapılara nasıl zarar verdiğini ve restorasyon çalışmaları ile fiziksel çevre denetimi sağlanmadığı takdirde geleneksel Antakya evlerinin genellikle su ve nem kaynaklı bozulmalar ile zamanla yok olacağını göstermektedir. Bölgede 2023 yılı şubat ayında meydana gelen depremler nedeniyle geleneksel konutlar da hasar almış, fiziksel çevre koşullarına karşı dirençleri azalmıştır. Antakya kent kültürünün ve tarihinin önemli bir parçası olan geleneksel Antakya evlerinin deprem sonrası mevcut durumu ile ilgili gerçekleştirilecek hasar tespit, onarım ve restorasyon süreçlerinde çalışmanın katkı sağlaması, kaynak olarak kullanılması öngörülmektedir