DSpace@ATÜ (Adana Alparslan Türkeş Bilim ve Teknoloji Universiti)
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Development of a Sustainable Polyculture Technique Using Asian Watergrass as Fish Feed in the Southern Coastal Region of Bangladesh
No full textGlobally, the quality and high cost of fish feed are vital issues for the development of sustainable aquaculture and food security. Present study was investigated in 4 treatments to find out the compatible species combination for polyculture using Asian watergrass as natural feed for fish in the tidally flooded coastal wetlands for a period of 6 months. Grass carp, common carp, tilapia, mrigal and silver barb were stocked in different species combination with an identical density of 12500 fish ha-1. In all treatments, grass carp and common carp were commonly stocked but other 3 species were disparate to stock among the treatments. Important water quality parameters were monitored those were suitable and acceptable range for aquaculture. The survival of fishes varied from 66.7±8.3 to 91.2±2.9% irrespective of fish species. The total fish production was found significantly higher (p<0.05), 5579.04±238.74 kg ha-1 in T3 followed by 4582.21±200.01 kg ha-1 in T2, 4571.52±189.78 kg ha-1 in T4 and 4448.37±247.26 kg ha-1 in T1 respectively. The results demonstrate that the combination of grass carp, common carp, tilapia, and silver barb in T3 was ideal compatible species for polyculture in coastal wetlands. This technique should be applied in haor, baor, beel, canals, and other water-logged areas pervaded by climate changes
Experimental investigation of nonuniform PV soiling
No full textPhotovoltaic (PV) module soiling, i.e., the accumulation of dust on PV module surfaces, poses several challenges to PV system performance. Among these challenges, the nonuniform deposition of soiling across the module surface has received scarce attention. Soiling is directly associated with an overall performance loss, but can also potentially give rise to localised hotspots that can lead to long-term PV module failure. Therefore, addressing the issues arising from this nonuniformity is not only important for optimising energy production, but also for enhancing system reliability, and ensuring the long-term operation of relevant power generation systems. In this study, the impact of nonuniform soiling on PV performance is investigated experimentally by examining soil deposition on the upper surfaces of low-iron glass samples. Samples positioned at four different tilt angles were collected on a monthly basis over a one-year study period. Since the horizontal samples were found to represent the worst-case conditions, the most soiled sample at horizontal tilt was divided into four zones, each housing a single monocrystalline solar cell and examined further. The findings reveal that the soiled sample experiences an average transmittance deterioration of 13% relative to a clean sample, and a maximum (relative) spatial variation of 4% between the four zones. These optical losses affect the amount of sunlight received by the cells, resulting in a power deterioration of similar to 6-7% per 5% drop in transmittance. The soiled sample experienced an average temperature rise of 2 degrees C, and an average power output (and efficiency) reduction of 30% relative to the clean sample, and a maximum (relative) spatial variation of 7% between the zones. The 30% average power loss measured in this nonuniform soiling case is more than double that which would be expected theoretically for a transmittance loss of 13% but from uniform soiling, so these results highlight the importance of addressing PV soiling for optimal PV performance, and of accounting for spatial soiling nonuniformity.UK Engineering and Physical Sciences Research Council (EPSRC) [EP/R045518/1]; Government of the Sultanate of Oman; Royal Society under an International Collaboration Award [ICA\R1\201302]; UK company Solar Flow Ltd.This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) [grant number EP/R045518/1] , and the Government of the Sultanate of Oman. The work was also supported by the Royal Society under an International Collaboration Award 2020 [grant number ICA\R1\201302] , and UK company Solar Flow Ltd. ( www.solar-flow.co.uk) . H.Y. gratefully acknowledges a TUEBI center dot TAK postdoctoral scholarship that supported his visit to Imperial College London. Data supporting this publication can be obtained on request from [email protected]. For the purpose of Open Access, the authors have applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission
Antibacterial and antioxidant properties and phytochemical screening of Laurus nobilis L. extract from Ethiopia
No full textMicrobial resistance to antibiotics and the shortage of efficient antimicrobial agent has necessitated the search for a better antimicrobial agent from various sources. Plants secondary metabolites are the major sources for discovery of new bioactive chemical compounds. The objective of this study was to determine the antibacterial and antioxidant activities of Laurus nobilis leaf extract and its essential oil against human pathogenic microorganisms and to analyse its chemical composition. The leaf of L. nobilis (500 g) was air-dried, powdered and extracted using four different solvents. The crude extract and the essential oil were tested against four Gram-negative and two Gram-positive bacterial strains. The radical scavenging activity of the crud extract was examined using DPPH assay. Bacterial inhibition activity of the crude extract increased with increased concentration from 25 mg/mL to 200 mg/mL. The maximum inhibition zone was recorded against Enterococcus faecalis 13.33±1.52 mm, Escherichia coli 14.33±1.53 mm and Salmonella typhimurium 16.00±1.00 mm, respectively. MeOH extract (1000 µg/mL) showed superior radical scavenging property (0.02) than ascorbic acid (0.05). The analysis of the oil using GC-MS indicated the presence of 48 chemical substances accounting for 91.4 % of the total compositions. The finding of this study showed that bay leaf has considerable antimicrobial and antioxidant activities. Further evaluation of this plant is recommended with particular focus on the mechanisms of action of the antimicrobial substance
The effect of the use of different milk types in Malatya cheese production on cheese quality characteristics during the maturation period
No full textLisansüstü Eğitim Enstitüsü, Gıda Mühendisliği Ana Bilim Dalı, Süt Teknolojisi Bilim DalıBu tez çalışması kapsamında, inek, koyun, inek koyun karışımı sütler ile Malatya peynirleri üretilmiş, bu üç çeşit peynir arasında depolama boyunca bazı özellikleri kıyaslanmaya çalışılmıştır. Bu amaçla üretilen peynirler 6 ay boyunca depolanmış ve depolamanın belirli sürelerinde (0., 1., 3. ve 6.aylar) örnek alınarak peynirlerin analizleri yapılmıştır. Üretilen Malatya peynirlerinin olgunlaşmaya bağlı bileşimleri (nem, protein, yağ, kül, tuz), olgunlaşma değerleri (pH, asitlik, toplam azot, suda çözünür azot, proteolitik olgunlaşma indeksi) ve uçucu bileşikleri belirlenmiştir. Araştırma sonunda inek sütünden üretilen Malatya peynirinin nem içeriği %49,6-50,7, protein içeriği %17,5-17,6, yağ içeriği %18,3-18,7, kül içeriği %12,6-13,8, tuz içeriği %10,9-%12,5, titrasyon asitliği 0,165-0,498, pH 6,54-6,36, olgunlaşma uzama indeksi %5,1-7,4, olgunlaşma yoğunluk indeksi %1,4-3,7 aralığında değişmiştir. İnek ve koyun sütlerinin karışımı ile üretilen Malatya peynirlerinde ise nem içeriği %49,0-50,5, protein içeriği %19,0-19,1, yağ içeriği %17,3-17,7, kül içeriği %11,8-14,2, tuz içeriği %10,0-%12,7, titrasyon asitliği 0,146-0,462, pH 6,35-6,62, olgunlaşma uzama indeksi %4,8-7,7, olgunlaşma yoğunluk indeksi %1,5-2,8 aralığında değişmiştir. Sadece koyun sütü kullanılarak üretilen Malatya peynirlerinin ise nem içeriği %51,1-52,3, protein içeriği %18,0-18,4, yağ içeriği %14,4-14,7, kül içeriği %14,1-15,8, tuz içeriği %12,5-%14,4, titrasyon asitliği 0,130-0,593, pH 6,37-6,62, olgunlaşma uzama indeksi %6,0-12,4, olgunlaşma yoğunluk indeksi %1,7-3,2 aralığında değişmiştir. Olgunlaşma süresince salamuradan peynire ve peynirden salamuraya madde difüzyonu nedeniyle bileşimde değişimler olduğu görülmüştür. Olgunlaşma süresince nem içeriklerinde azalma, tuz ve kül miktarlarındaki artış ile çözünür azot fraksiyonlarının olgunlaşmanın ilk aylarındaki azalması bu süreçle ilişkilendirilmiştir. Uçucu bileşik analizleri sonucunda üretilmiş olan Malatya peynirlerinde 11 adet asit, 1 adet alkol ve bir adet uçucu fenol bileşiği saptanmıştır. Olgunlaşma süresince ise toplam uçucu bileşik miktarının arttığı belirlenmiştir. Anahtar Kelimeler: Malatya peyniri, olgunlaşma, proteoliz, uçucu bileşikler.Within the scope of this thesis study, Malatya cheeses were produced with cow, sheep and cow-sheep mixture milk, and some characteristics of these three types of cheese were compared during storage. For this purpose, the cheeses produced were stored for 6 months and samples were taken at certain periods of storage (0th, 1st, 3rd and 6th months) and the cheeses were analyzed. Compositions of produced Malatya cheeses depending on ripening (moisture, protein, fat, ash, salt), ripening values (pH, acidity, total nitrogen, water-soluble nitrogen, proteolytic ripening index) and volatile compounds were determined. The results for the Malatya cheese produced with cow milk showed that moisture, protein, fat, ash and salt contents were varied in the range of %49.6-50.7, %17,5-17,6, %18.3-18.7, %12.6-13.8, and %10.9-%12.5, while titratable acidity, pH, ripening extension index and ripening depth index were detected to be in the range of 0.165-0.498, 6.54-6.36, %5.1-7.4 and %1.4-3.7, respectively. In Malatya cheeses produced with a mixture of cow and sheep milk, moisture content varied between 49.0-50.5%, protein content between 19.0-19.1%, fat content between 17.3-17.7%, ash content between 11.8-14.2%, salt content between 10.0-12.7%, titratable acidity between 0.146-0.462, pH between 6.35-6.62, ripening extension index between 4.8-7.7%, and ripening depth index between 1.5-2.8%. The moisture content of Malatya cheeses produced using only sheep milk varied between 51.1-52.3%, protein content between 18.0-18.4%, fat content between 14.4-14.7%, ash content between 14.1-15.8%, salt content between 12.5-14.4%, titratable acidity between 0.130-0.593, pH between 6.37-6.62, ripening extension index between 6.0-12.4%, and ripening depth index between 1.7-3.2%. It was observed that there were changes in composition due to the diffusion of substances from brine to cheese and from cheese to brine during ripening. The decrease in moisture content, the increase in salt and ash contents and the decrease in soluble nitrogen fractions in the first months of ripening were associated with this process. As a result of volatile compound analyses, 11 acids, 1 alcohol and 1 volatile phenol compounds were detected in the Malatya cheeses produced. It was determined that the total concentrations of volatile compounds increased during ripening. Keywords: Malatya cheese, ripening, proteolysis, volatile compounds
DFT analysis of salicylideneaniline derivatives as corrosion inhibitors for mild steel
No full textSchiff bases are important in corrosion inhibition due to their ability to form stable complexes with metal ions and create protective layers on metal surfaces, thereby extending the lifespan of structural materials in various industrial applications. In this study the Salicylideneaniline and its derivatives were analyzed as corrosion inhibitor versus mild steel corrosion via DFT analysis. The eight molecules were chosen; salicylideneaniline, 2-(benzylideneamino)phenol, 4-(benzylideneamino)phenol, 2-phenyldiazenylphenol, 2-Phenylazo-4-methylphenol, 3-methyl-2-phenyldiazenyl phenol, 2-[(2-methylphenyl)diazenyl]phenol, 4-phenyldiazenylbenzene-1,3-diol), for this purpose. The Gaussian 03 program and the 6-311++G (d, p) basis set was used. Electronic properties such as the energy of the highest occupied molecular orbital (EHOMO), energy of the lowest unoccupied molecular orbital (ELUMO), energy gap (?E) between LUMO and HOMO, dipole moment, and charges on the backbone atoms, ESP were determined
Makine öğrenmesi yaklaşımlarıyla glioblastoma multiformede mikrorna bazlı ilaç repozisyon analizleri
No full textLisansüstü Eğitim Enstitüsü, Biyomühendislik Ana Bilim Dalı, Biyomühendislik Bilim DalıGlioblastoma (GBM) tüm beyin tümörleri arasında en yaygın kanserdir ve en kötü prognoza sahiptir. Bu tezde, GBM'nin biyomoleküler mekanizmalarını göstermek ve daha iyi anlamak için GBM verilerine çeşitli biyoinformatik analizler ve makine öğrenimi sınıflandırma teknikleri uyguladık. İlk olarak, analiz edilecek GBM veri kümeleri seçilmiştir. Ardından, transkriptom ve miRNA verilerinin ekspresyon analizleri gerçekleştirilmiştir. Değişmiş ekspresyona sahip genler ve miRNA'lar tanımlanmış, ortak genlerle birlikte eksprese edilen gen kümeleri ve miRNA'lar tarafından hedeflenen genler belirlenmiş ve ko-ekspresyon ağı çizilmiştir. Bu gen kümelerinin prognostik özellikleri incelenmiş ve Random Forest (RF), Support Vector Machine (SVM), Naive Bayes (NB) ve The K-Nearest Neighbours (KNN) gibi makine öğrenmesi sınıflandırma algoritmaları ile performans analizleri gerçekleştirilmiştir. Performans analizleri sonucunda RF, SVM ve KNN algoritmalarının %80'in üzerinde doğruluk skorları ile mevcut gen grupları ile çalışan güvenilir ve doğru sınıflandırma algoritmaları olduğu görülmüştür. Ayrıca yukarı ve aşağı doğru özellik seçimi ile elde edilen sonuçlara göre SEPT4, VAMP1, MAP1A, KIF5C, NPTX1 ve ATP8A1 genlerinin yüksek etkileşim verdiği ve GBM hastalığında önemli biyobelirteç adayları olabileceği tespit edilmiştir. Ayrıca elde edilen gen kümeleri ilaç yeniden konumlandırma analizleri için kullanılmıştır. Bu testler sonucunda gen ko-ekspresyon ağ modülü ve miRNA bazlı ko-ekspresyon ağ modülü verilerine ait gen kümelerinin içinde yer alan makine öğrenmesi analizlerinde en yüksek etkileşimlere sahip olan gen grupları ile ortak ilaçları belirlenmiştir. GBM tedavisinde kullanılabilecek, Emetine Dihydrochloride Hydrate (74), 16beta Bromoandrosterone, AS605240, 480743.cdx, BRD K00627859, HDAC6 inhibitörü ISOX, BRD-K12184916 ve 16-HYDROXYTRIPTOLIDE gibi çok sayıda ilaç adayı bulundu. Bu ilaçların ve küçük moleküllerin gelecekteki klinik çalışmalarda test edilebileceğini ve GBM tedavisi için yeni ilaç adayları olabileceği belirlenmiştir.Glioblastoma (GBM) is the most common cancer among all brain tumours and has the worst prognosis. In this thesis, we applied various bioinformatic analyses and machine learning classification techniques to GBM data to illustrate and better understand the biomolecular mechanisms of GBM. First, GBM datasets to be analysed were selected. Then, expression analyses of transcriptome and miRNA data were performed. Differentially expressed genes and miRNAs were identified, gene clusters co-expressed with common genes and genes targeted by miRNAs were identified, and the co-expression network was drawn. The prognostic properties of these gene clusters were examined and performance analyses were performed with machine learning classification algorithms such as Random Forest (RF), Support Vector Machine (SVM), Naive Bayes (NB) and The K-Nearest Neighbours (KNN). As a result of the performance analyses, RF, SVM and KNN algorithms were found to be reliable and accurate classification algorithms that work with existing gene groups with accuracy scores above 80%. In addition, according to the results obtained by upward and downward feature selection, it was determined that SEPT4, VAMP1, MAP1A, KIF5C, NPTX1 and ATP8A1 genes give high interaction and may be important biomarker candidates in GBM disease. In addition, the gene clusters obtained were used for drug repositioning analyses. As a result of these tests, the gene groups with the highest interactions in the gene clusters belonging to the gene co-expression network module and miRNA-based co-expression network module data in machine learning analyses and their common drugs were determined. A large number of drug candidates such as Emetine Dihydrochloride Hydrate (74), 16beta Bromoandrosterone, AS605240, 480743.cdx, BRD K00627859, HDAC6 inhibitor ISOX, BRD-K12184916 and 16-HYDROXYTRIPTOLIDE were found for the treatment of GBM. It was determined that these drugs and small molecules can be tested in future clinical trials and may be new drug candidates for the treatment of GBM
Determining the Interaction of Social Sustainability with the Physical Environment: A Case Study of Adana, Turkey
No full textSocial sustainability has emerged as a critical factor in evaluating societal welfare and well-being. Consequently, researchers have initiated the development of a theoretical framework to delineate the components of social sustainability, achieving notable progress in this endeavor. However, the interplay between the social dimension and the environmental and economic dimensions remains insufficiently explored in user experiences, posing challenges in integrating social sustainability into preliminary design parameters in the built environment and resulting in socially inefficient spaces. This study seeks to elucidate the relationship between social sustainability and the environment while devising a measurement methodology that encompasses the physical environment. Concentrating on public spaces, pivotal in daily experiences and reflective of individual interactions, the research was conducted across five distinct public spaces in the Seyhan district of Adana. Methodologically, the study employed field research, preliminary examination, and statistical analysis. Data collection techniques, including surveys, observations, and measurements, were utilized to unveil statistically significant correlations between social sustainability and the physical environment of public spaces. Consequently, this study delineates the dimensions of these relationships and translates them into actionable design data
Karıştırıcılı bir ısı değiştirici etkinliğine farklı parametrelerin etkisinin deneysel ve sayısal incelenmesi
No full textLisansüstü Eğitim Enstitüsü, Makine Mühendisliği Ana Bilim Dalı, Termodinamik Bilim DalıEnerji verimliliğinin artışı hem olumsuz çevresel etkilerin azaltılması hem de işletme maliyetlerinin düşürülmesi açısından önemini korumaktadır. Endüstriyel işletmelerdeki ısıl yükler, atık ısılar, enerji tüketiminde önemli bir paya sahiptir. Bu proseslerin verimli ve tasarruflu bir şekilde yürütülmesinde ısı değiştiricilerin payı büyüktür. Bu tez çalışmasında karıştırıcılı bir ısı değiştiricinde mekanik karıştırıcının dönme hızı, Reynolds sayısı, akışkan giriş sıcaklıklarının ısı transfer performansına olan etkisi deneysel olarak incelenmiştir. Hesaplamalı akışkanlar dinamiği yazılımıyla oluşturulan sayısal model doğrulandıktan sonra, karıştırıcı çark ve kanat geometrisinin ısı transfer performansıma olan etkisi incelenmiştir. Sayısal çalışmada ANSYS Fluent 2022 R1 yazılımında hareketli ağ yapısının modellenmesi için Hareketli Referans Sistemi (MRF) ve çözüm için düşük Reynolds düzeltmeli SST k-? türbülans modeli kullanılmıştır. Sonuç olarak; çark hızının 0'dan 200 d/dk'ya kadar artırılması, ısı transfer etkinliğinde %55,1 artış, çark yüksekliğinin H=10 mm'den H=40 mm'ye artırılması ısı transfer etkinliğinde %17,2 artış, çark çapının D=40 mm'den D=100 mm'ye artırılması ısı transfer etkinliğinde %15,9 artış, kanat açısının ?=0°'dan ?=45°'e kadar artırılması ısı transfer etkinliğinde %14,4 artış, kanat sayısının n=2'den n=3'e çıkarılması ısı transfer etkinliğinde %12,6 artış ve çark sayısının S=1'den S=2'ye çıkarılması ise ısı transfer etkinliğinde %16,7 artış sağladığı tespit edilmiştir. Bu tez çalışmasından elde edilen sonuçlarla, termal proseslerde ısı değiştiricisine ait verimliliklerin artırılmasına bağlı olarak enerji tasarruflu sistemlerin geliştirileceği değerlendirilmiştir.Increasing energy efficiency remains crucial for both reducing adverse environmental impacts and reducing operational costs. Thermal loads and waste heat in industrial operations account for a significant portion of energy consumption. Heat exchangers play a major role in running these processes efficiently and economically. In this thesis, the effects of the mechanical stirrer's rotational speed, Reynolds number, and fluid inlet temperatures on the heat transfer performance in a stirred heat exchanger were experimentally investigated. After validating the numerical model created with computational fluid dynamics software, the impact of the stirrer's impeller and blade geometry on heat transfer performance was examined. In the numerical study, the Moving Reference Frame (MRF) for modeling the moving mesh structure and the low Reynolds corrected SST k-? turbulence model were used for the solution in ANSYS Fluent 2022 R1 software. As a result: increasing the impeller speed from 0 to 200 rpm resulted in a 55.1% increase in heat transfer effectiveness; increasing the impeller height from H=10 mm to H=40 mm resulted in a 17.2% increase; increasing the impeller diameter from D=40 mm to D=100 mm resulted in a 15.9% increase in heat transfer effectiveness; increasing the blade angle from ?=0° to ?=45° resulted in a 14.4% increase in heat transfer effectiveness; increasing the number of blades from n=2 to n=3 resulted in a 12.6% increase in heat transfer effectiveness; and increasing the number of impellers from S=1 to S=2 resulted in a 16.7% increase in heat transfer effectiveness. The results of this thesis suggest that improving the efficiency of heat exchangers in thermal processes can lead to the development of more energy-efficient systems
Economic Uncertainty in the Post-Pandemic Era: Policy Responses and the Way Forward
No full textThe global economy has experienced many challenges in recent times, particularly in the shadow of the COVID-19 pandemic, such as dwindling demand, supply chain disruptions, declining growth rates, further pandemic waves, and increasing poverty and inequality to name but a few. Four years after the pandemic, economies are still struggling to achieve sustainable economic growth and development. While much has been written about the impact of COVID-19 on various sectors and economies, this is the first book to underscore the post-COVID global uncertainties that are still occurring on the world stage and further, to present the recent challenges such as geo-political tensions, war, economic disturbances, climate change, the energy crisis in Europe, recession in developed economies and its effect on developing and least developed economies. The book starts by setting the grounds for further discussion of the present challenges as well as future implications. In addition to examining the immediate issues which occurred with the onset of the pandemic, it explores these from the perspective of developed, developing, and least developed countries. The wide-ranging topics covered by the book include the ongoing Russia-Ukraine War, China’s increasing economic dominance in neighbouring countries, the economic collapse of Sri Lanka and Pakistan, the factors that led to the technology layoffs and the future of global employees and economies. The book goes beyond looking at sector-specific factors and broadly outlines country-specific instabilities, policy choices and the way forward. The book will be of interest to students of macroeconomics, development and international economics, and international relations as well as researchers and policymakers. © 2025 selection and editorial matter, Shilpa Deo and Fatma Feyza Gündüz; individual chapters, the contributors
Vibration behavior of a 3D-printed hybrid polymer bearing with outer race defect
No full textPurposeIn industry applications, polymer hybrid bearings have become widespread in recent years owing to the lack of lubricant requirements, particularly in areas requiring hygiene. The additive manufacturing method gives significant advantages to have complex machinery parts, and it has become popular in the industry in recent years. However, it has some inherent disadvantages caused by layered deposition/addition of the materials, and the probability of the localized defect is much higher than in the conventional manufacturing methods. This study aims to investigate the effect of the outer race defect on the characteristics of vibration and service lifetime of hybrid polymer ball bearings produced with the stereolithography (SLA) additive manufacturing method.Design/methodology/approachIn this study, polymer bearings' races were produced with the additive manufacturing SLA method, and the outer race defect was analyzed with measured vibrations.FindingsThe results show that the additive manufacturing method suggests a practical solution for producing a polymer hybrid ball bearing. On the other hand, the hybrid three-dimensional-printed bearing, which has an outer race defect, worked for approximately 8 h without any problems under a 1 kg load and a shaft speed of around 1,000 rpm. In addition, when there is a defect in the outer and/or inner race of the ball bearing, the crest factor and kurtosis of the vibration are higher than faultless ball bearing, as expected.Originality/valueThis paper provides valuable information on the lifetime and vibration characteristics of polymer hybrid ball bearing produced by means of additive manufacturing.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2023-0183/Gazi University Scientific Research Projects Unit [06/2018-08]Funding statement: Gazi University Scientific Research Projects Unit funded the presented study with Grant No. 06/2018-08, Turkey