DSpace@ATÜ (Adana Alparslan Türkeş Bilim ve Teknoloji Universiti)
Not a member yet
3463 research outputs found
Sort by
A Multi-Country Statistical Analysis Covering Turkey, Slovakia, and Romania in an Educational Framework
No full textThis paper uses hierarchical regression analysis, a statistically robust method, to explore the correlations between two meteorological parameters and three particulate matter concentrations. The dataset is provided by six sensors located in three cities from three countries, and the measurements were taken simultaneously for three months at each minute. Analyses and calculations were performed with the Statistical Package for the Social Sciences (SPSS). The results underscore that the complexity of air pollution dynamics is affected by the location even when the same type of sensors is used, and emphasize that a one-size-fits-all approach cannot effectively address air pollution. The findings are helpful from three perspectives: for education, to show how to handle and communicate a solution for local communities' issues about air pollution; for research, to understand how easy a university can generate and analyze open-source data; and for policymakers, to design targeted interventions addressing each country's challenges.European Union [2021-1-RO01-KA220-HED-000030286]The support of the Advtech_AirPollution project (Applying some advanced technologies in teaching and research about air pollution, 2021-1-RO01-KA220-HED-000030286) funded by the European Union within the framework of the Erasmus+ Program is gratefully acknowledged
Antibacterial and antioxidant activity of compounds from Citrus sinensis peels and in silico molecular docking study
No full textThe increasing prevalence of drug resistance, adverse side effects of existing antibiotics, and the resurgence of previously known infections have necessitated the search for new, safe, and effective antimicrobial agents. The peels of Citrus sinensis (300 g) were extracted using maceration and ultrasonic-assisted extraction methods with ethanol, resulting in yields of 20.99 g and 11.5 g (7%, 7.5%), respectively. Silica gel column chromatographic separation of the ethanol extract yielded N-(1,3,4,5-tetrahydroxydecan-2-y1)octanamide (1), decanoic acid (2), ?-sitosterol-3-O-?-D-glucopyranoside derivative (3), and (z)-ethyl tetradec-7-enoate (4). GC-MS analysis of the essential oil detected 7 chemical components accounting for 99.84% of the total composition of which limonene was found to be the predominant constituent (87.5%). In vitro antibacterial tests revealed promising zones of inhibition by ethanol extract (12.67±0.58 mm, at 150 mg/mL), compound 4 (15.67±2.88 mm, at 6 mg/mL), and compound 1 (12.00±0.00 mm, at 6 mg/mL) against E. faecalis, S. typhimurium, and P. aeruginosa, respectively, compared to gentamicin (13.00±1.73 mm, 18.00±1.00 mm, and 16.67±1.15 mm, respectively at 10 µg/mL). DPPH radical scavenging activity indicated that compound 1 exhibited an IC50 value of 0.05 mg/mL, compared to ascorbic acid's 0.016 mg/mL. In silico molecular docking studies revealed that compounds 1 and 3 had the lowest scoring poses against E. coli DNA gyrase B enzyme, human peroxiredoxin 5, and S. aureus pyruvate kinase, respectively. These findings support traditional applications of Citrus peels in treating infectious diseases, particularly against Gram-positive strains, and highlight their potential use as antibacterial ingredients in cosmetics
A study on the production opportunities of breadsticks containing quiona flour
No full textLisansüstü Eğitim Enstitüsü, Gıda Mühendisliği Ana Bilim DalıBu araştırmada kinoa unu ilaveli fonksiyonel bir gıda ürünü potansiyelini araştırmak için bir ürün denemesi gerçekleştirilmiştir. Buğday ununa %10, %20, %30 kinoa unu ilaveli galeta ve kontrol galeta örneği olmak üzere 4 farklı galeta çeşidi üretilmiştir. Duyusal analiz sonucunda en çok beğenilen kinoa unu ilaveli galeta olan %10 kinoa unu ilaveli galetanın nem, kül, protein, yağ, karbonhidrat, enerji, L*,a*, b*, c*, h, toplam fenolik madde, antioksidan aktivite değerleri sırasıyla (%4.35, %1.43, %12.56, %5.48, %76.16, 379.89 kcal, 75.76, 8.80, 26.94, 28.53, 72.10, 115.7 µg GAE/g, 2.22 mmol/g) olarak hesaplanmıştır. Duyusal analiz sonucunda en çok beğenilen kinoa unu ilaveli galeta olan %10 kinoa unu ilaveli galetanın diyet lif oranı ise % 6.08 olarak hesaplanmıştır. Kinoa unu ikame edildikçe galetalardaki yağ miktarı, karbonhidrat oranı, enerji değeri, toplam fenolik madde, antioksidan aktivitesi, toplam diyet lif miktarı, kül miktarı ve nem içeriği artmış, sertlik azalmıştır. Galetaların çap, uzama ve yayılma oranında azalma meydana gelmiştir. Ürün içerisindeki kinoa unu miktarı arttıkça L* parlaklık ve h renk açısı değerleri azalırken, a* kırmızılık, b* sarılık, c* renk doygunluğu değerleri artmıştır. Kinoa unu ilavesi, hamurun reolojik özelliklerini önemli ölçüde etkilemiştir. Galeta formülasyonlarına kinoa ununun %20'ye varan oranlarda dahil edilmesi duyusal olarak kabul edilebilir bulunmuş, besleyici olarak değerli bir ürünün geliştirilme olasılığını ortaya koymuştur. Bu çalışma kimyasal bileşim bakımından, iyileştirilmiş beslenme özelliklerine sahip gıdaların hazırlanmasında değerli bir bileşen olarak kinoa ununun potansiyelini ortaya çıkarmıştır.A product trial was carried out to explore the potential of a functional food product containing quinoa flour. To this end, four different types of breadsticks were produced, including the control sample as well as breadsticks containing 10%, 20%, and 30% quinoa flour in addition to wheat flour. As a result of the sensory analysis, moisture, ash, protein, fat, carbohydrate, energy, L*,a*, b*, c*, h, total phenolic substance, antioxidant activity values of the breadcrumbs with 10% quinoa flour added, which is the most popular breadcrumbs with quinoa flour respectively (4.35%, 1.43%, 12.56%, 5.48%, 76.16%, 379.89 kcal, 75.76, 8.80, 26.94, 28.53, 72.10, 115.7 µg GAE/g, 2.22 mmol/g). As a result of the sensory analysis, the dietary fibre ratio of the breadcrumbs with 10% quinoa flour added, which was the most popular, was calculated as 6.08%. The more quinoa flour was added, the mineral composition of the product increased due to the increases in the amount of fat, carbohydrate and energy value, total phenolic substance and antioxidant activity, total dietary fibre amount, and ash amount in the breadsticks, increased in the products, the moisture increased while hardness decreased. Decreases were observed in the diameter, elongation, and spreading rates. As the amount of quinoa flour in the product increased, L* brightness and h colour angle values decreased. As the quinoa rate increased, a* redness, b* yellowness, and c* colour saturation values increased. The addition of quinoa flour significantly affected the rheological properties of the dough. According to the results of the analysis conducted, water absorption value ranges from 61.8 to 64.56, and the water absorption in the flour increases as the rate of quinoa flour added increases. The addition of quinoa flour in the breadsticks formulations developed by rates up to 20% has been found to be sensorial acceptable and revealed the possibility of developing a nutritionally valuable product. This study demonstrates the potential of quinoa flour, which is deemed as a valuable ingredient in the development of food products that have enhanced nutritional properties, in terms of chemical composition and might contribute to the development of a range of bakery products with added nutritional value
Valorization of cocoa, tea and coffee processing by-products-wastes
No full textThe growing threat of food insecurity together with some challenges in demography, health, malnutrition, and income instability around the globe has led researchers to take sustainable solutions to ensure secure production and distribution of food. The last decades have been remarkable in the agri-food supply chain for many food industries. However, vast quantities of food by-products and wastes are generated each year. These products are generally disposed in the environment, which could have remarkable adverse effects on the environment and biodiversity. However, they contain significant quantities of bioactive, nutritional, antioxidative, and aroma compounds. Their sustainable use could meet the increased demand for value-added pharmaceutical, nutraceutical, and food products. The amount of agri-food wastes and their disposal in the environment are predicted to double in the next decade. The valorization of these by-products could effectively contribute to the manufacture of cheaper functional food ingredients and supplements while improving regional economy and food security and mitigating environmental pollution. The main aim of this chapter is to present an understanding of the valorization of the wastes and byproducts from cacao, coffee and tea processing with a focus on their bioactive, nutritional, and antioxidant capacity
The effect of fluxing agents and heat treatment on the leucite crystallization in bio glass–ceramic composites
No full textThe main purpose of the present study is to produce leucite-based bio glass–ceramic composite considering the results from the previous studies; however, nucleating oxides are excluded from the production process. The effects of fluxing agents and heat treatment on leucite crystallization in bio glass–ceramic composites are in the center of investigation. At the beginning, a series of laboratory experiments were conducted using the relevant data specified in the literature, then, three different compositions were chosen considering their high leucite content. In these three compositions, the amounts of K2O, Al2O3, and SiO2 were fixed and the amounts of the Na2O, Li2O, CaO, and B2O3 were changed. The batches were glassified and then quenched into water. The produced frits were ground under 63 microns, dried, and shaped. By evaluating the critical temperatures (Tg and Tc/Tp) of DTA, two heat-treatment stages were defined and samples were exposed to cycles. During characterization studies, all samples from two cycles contained leucite as the main phase accompanied by a glassy phase. When the heat-treatment temperature was higher and the period became longer, the amount of leucite phase increased. CTE values were changed with the content of leucite crystal in the glass–ceramic system, as expected. The viscosity curves as functions of temperature were drawn from the compositions using the Lakatos and Fluegel empirical model and correlated with the crystallization behavior. The well-crystallized leucite glass–ceramic structure (42% leucite) was obtained by the recipe LC02, without any addition of nucleating oxides, (after HT02 cycle), with a value of ? is 14.14 10?6/°C. © 2022, The Author(s) under exclusive licence to Australian Ceramic Society
L-metiyoninaz enziminin üretimi, anti-kanserojen özelliklerinin ve gıda endüstrisinde kullanım olanaklarının araştırılması
No full textFen Bilimleri Enstitüsü, Gıda Mühendisliği Ana Bilim DalıBu çalışmada L-metiyoninaz enzimi, yardımcı peynir kültürü olan Brevibacterium linens BL2'den kısmen saflaştırılmıştır. Enzimin spesifik aktivitesi 3.055 ünite/mg olarak belirlenmiştir. İlk olarak, L-metiyoninazın Glioblastoma hücrelerine olan sitotoksik etkileri değerlendirilmiştir. U87MG ve T98G glioblastoma hücre hatlarının IC50 değerleri, 24 saatlik inkübasyon sonrası nötral kırmızı canlılık analizi ile sırasıyla 5.792 ünite/mL ve 5.215 ünite/mL olarak saptanmıştır. L-metiyoninaz, etoposid ile birlikte kombinasyon halinde kullanıldığında aynı hücre hatlarına karşı sitotoksik etkiyi de artırdığı görülmüştür. Bu, U87MG hücrelerinin canlılığında önemli bir azalmaya yol açmış ve 48 saatlik inkübasyon süresinde kontrol grubuyla karşılaştırıldığında canlılığı %24.35'e azalttığı gözlemlenmiştir. Benzer şekilde, T98G hücrelerinin büyümesi hem L-metiyoninaz hem de etoposid tarafından inhibe edilmiştir. 48 saatlik inkübasyon sonunda hücresel canlılık, kontrol gruba kıyasla %37.74'e düşüş göstermiştir. Brevibacterium linens BL2'den saflaştırılan L-metiyoninaz enzimi Fare Embriyonik Fibroblast (MEF) hücreleri ve İnsan Keratinosit Hücre Hattı (HaCaT) üzerinde glioblastoma hücrelerine göre daha düşük sitotoksik etki göstermiştir. L-metiyoninaz ve etoposidin kombinasyon uygulaması, HaCaT hücre canlılığının genel olarak %63.02'ye ve MEF hücre canlılığının %58.99'a düşürmüştür. Giemsa, DAPI ve F-aktin boyama yöntemleri ile hem hücre popülasyonunda hem de morfolojideki değişiklikleri doğrudan tespit edilmiştir. L-metiyoninaz ve etoposidin birlikte uygulanması, glioblastomanın yara iyileştirme yeteneğini azaltmasının yanında, hücresel göçün baskılanmasında dikkate değer bir etkinlik gösterdiği gözlemlenmiştir. Klonojenik deneyler, L-metiyoninaz ve etoposid uygulanmasının, 21 günlük inkübasyon süresi boyunca glioblastoma hücrelerinin koloni sayısında önemli bir azalmaya neden olduğunu göstermiştir. RT-qPCR sonuçları, L-metiyoninazın, kanser hücrelerinin hayatta kalması için hayati olan Survivin ve C-Myc genlerinin ekspresyonunda azalmaya neden olurken hücre ölümü için gerekli olan Kaspaz-3 geninin ekspresyonunu arttırdığını göstermektedir. Bu araştırma aynı zamanda L-metiyoninazın çedar peyniri bulamaçlarına uygulanmasının uçucu sülfür bileşikleri üretimi ve peynir mikrobiyomu değişimi üzerindeki etkileri de araştırılmıştır. Çedar bulamacı numuneleri, yeni nesil dizileme ve GC-MS analizi kullanılarak incelenmiştir. Deneyin ilk gününde numunelerde çoğunlukla Lactococcus ve Streptococcus suşlarının baskın olduğu görülmüştür. Ancak, dokuzuncu günde, tüm örneklerde belirgin bir şekilde Limosilactobacillus, Lactobacillus, Enterococcus ve Lacticaseibacillus gibi mikroorganizmaların varlığı ile karakterize edilen mikrobiyal çeşitlilikte kayda değer bir artış gözlenmiştir. İlginç bir şekilde, Lactococcus ve Streptococcus, dokuzuncu günde hala baskın türler olarak kalmıştır. Ek olarak, L-metiyoninaz enzimi ve Brevibacterium linens BL2'nin ilave edilmesi, Metanetiyol ve Dimetil trisülfür gibi uçucu kükürt bileşiklerinin üretimini teşvik etmiştir. Fermantasyonun erken aşamasında, L-metiyoninaz enzimi çedar bulamaçlarında 1490.2 ± 1.31 (µg/kg kuru madde) metanetiyol ve 65.8 ± 0.04 (µg/kg kuru madde) dimetil trisülfit üretmiştir. Bu sonuçlar, L-metiyoninazın çedar peyniri üretiminde ekonomik değer arttırıcı potansiyele sahip bir gıda endüstrisi enzimi olarak gelecekte kullanılabileceği görüşünü desteklemektedir.In this study, L-methioninase was partially purified from Brevibacterium linens BL2. The specific activity of this enzyme was 3.055 units/mg. The cytotoxic properties of L-methioninase against Glioblastoma cells were evaluated. The IC50 values of U87MG and T98G glioblastoma cell lines were found to be 5.792 units/mL and 5.215 units/mL, respectively, using a neutral red viability assay after 24 h of incubation. L-methioninase also increased the cytotoxic effect of etoposide in the same cell lines when combined. This led to a notable decrease in the viability of U87MG cells, with only 24.35% remaining compared with the control group after 48 h of incubation. Similarly, the growth of T98G cells was inhibited by both L-methioninase and etoposide compared to the control group. Following After 48-hour phase of incubation, the cellular viability decreased by 37.74% compared to that of the untreated group. Notably, the cytotoxic effects of the L-methioninase enzyme produced by Brevibacterium linens on Mouse Embryonic Fibroblast (MEF) cells and Human Keratinocyte Cell Line (HaCaT) cells, however, were found to be lower than those of etoposide. The combined administration of L-methioninase and etoposide resulted in an overall decrease in HaCaT cell viability to 63.02% and MEF cell viability to 58.99%. The use of staining methods such as Giemsa staining, DAPI staining, and F-actin staining enabled the direct detection of alterations in both cell population and morphology. The co-administration of L-methioninase and etoposide showed notable effectiveness in suppressing cellular migration, as evidenced by the results of a wound healing experiment. In a clonogenic experiment, the administration of L-methioninase and etoposide led to a significant decrease in the number of colonies observed throughout the 21-day incubation period. According to the RT-qPCR results, L-methioninase caused a decrease in the expression of c-Myc and survivin genes, while simultaneously increasing the expression of Caspase-3. This study also investigated the effects of applying L-methioninase to cheddar cheese slurries on the production of volatile sulfur compounds and cheese microbiome alteration. The cheddar slurry samples were analyzed using next-generation sequencing and GC-MS analysis. On the first day of the experiment, the samples were mostly dominated by Lactococcus and Streptococcus strains. On the ninth day, a notable augmentation in microbial diversity was found in all samples, characterized by the presence of Limosilactobacillus, Lactobacillus, Enterococcus, and Lacticaseibacillus in considerable quantities across all samples. Lactococcus and Streptococcus were the predominant species. The introduction of L-methioninase and Brevibacterium linens BL2 led to the formation of volatile sulfur compounds, namely, Methanethiol and Dimethyl trisulfide. During the first stage of fermentation, the L-methioninase enzyme generated a quantity of 1490.2 ± 1.31 (µg/kg dry matter) of Methanethiol and 65.8 ± 0.04 (µg/kg dry matter) of Dimethyl trisulfide inside the cheddar slurry. The present study provides evidence supporting the possibility of L-methioninase as a promising option for food enzymes in cheddar cheese manufacturing, thus presenting substantial economic benefits
Flow control over a circular cylinder using vortex generators: Particle image velocimetry analysis and machine-learning-based prediction of flow characteristics
No full textControlling the flow around circular cylinders is crucial to mitigate vortex-induced vibrations and prevent structural damage in a range of applications, such as marine and offshore engineering, tall buildings, long-span bridges, transport ships, and heat exchangers. In this study, we aimed to control the turbulent flow structure around a circular cylinder by placing vortex generators (VGs). We examined the flow structure using particle image velocimetry (PIV). This enabled quantitative data acquisition, intuitive flow visualization, and drag coefficient determination from PIV data. We developed artificial neural network (ANN) models that successfully predict both mean and instantaneous flow characteristics for different scenarios. Our findings show that using VGs elongated the wake and increased vortex formation lengths while reducing velocity fluctuations and the drag coefficient. A minimum drag coefficient of 0.718 was achieved with VGs oriented at alpha = 60 degrees & beta = 60 degrees, reducing the drag by 35.3% compared to the bare cylinder. The drag coefficient exhibited a substantial inverse correlation with both wake and vortex formation lengths. This study is significant for controlling flow structures, providing detailed insights into the near-wake region, and highlighting the potential applications of machine learning in fluid dynamics.Scientific and Technological Research Council of Turkiye [1059B192201266]Abdulkerim Okbaz expresses gratitude to the TUBITAK-2219 International Postdoctoral Research Fellowship Program, supported by The Scientific and Technological Research Council of Turkiye, for funding a segment of this study carried out at the Georgia Institute of Technology (2022, Grant# 1059B192201266)
Protection of Multi-Terminal VSC HVDC Hybrid Transmission Line
No full text25th European Conference on Power Electronics and Applications, EPE 2023 ECCE Europe -- 4 September 2023 through 8 September 2023 -- Aalborg -- 193133This paper presents a fast fault detection scheme for a hybrid line in a multi-terminal (MT) voltage source converter (VSC) high voltage DC (HVDC) system. The proposed method is based on the primary and secondary protection scheme. The discrete wavelet transforms (DWT) with Teager energy operator (TEO) and voltage polarity comparison are applied to detect the faulted line for primary and secondary protection schemes, respectively. The main and backup protection schemes are based on non-pilot and pilot methods, respectively. The proposed main and backup methods are robust against high impedance faults (HIFs). The proposed protection scheme is verified under different fault points applied on an MT-HVDC test system. The case study is performed using PSCAD/EMTDC software. Simulation results show the effectiveness of the proposed protection method for the VSC HVDC transmission line. © 2023 EPE Association
Production of microencapsulated enzyme-modified cheese (EMC) powder: Impact of wall material combinations, their concentrations, and homogenisation pressures
No full textEnzyme-modified cheese (EMC) is a concentrated cheese flavour, and microencapsulation can improve its physical properties while preserving flavour. This study performed microencapsulation of EMC in two stages: emulsification and spray drying. Different combinations of proteins (sodium caseinate, whey protein concentrate) and carbohydrates (lactose, maltodextrin, oxidised starch) at varying homogeni-sation pressures (500, 1000, 2000 bar) were used to determine the most appropriate wall material combination, and emulsions with different concentrations of wall materials (23, 36.5, 50%) spray-dried to select the best microencapsulation formulation. Emulsion properties and the physical, chemical, and sensorial characteristics of the powders were evaluated. Microencapsulation enhanced the physical properties of powders, increased the drying yield, reduced the loss of free fatty acids, and increased the concentration of ester compounds. The best powder was produced using whey protein concentrate/ lactose at a concentration of 50% of the total dry matter in the emulsion, with a homogenisation pressure of 500 bar.(c) 2023 Elsevier Ltd. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK) [115O229]This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) [project no: 115O229] . The authors are also grateful to the Novozymes for providing the en- zymes. We would like to thank our colleague Pelin Purcuklu for her voluntary assistance in the laboratory during the emulsion analysis
A Review of Published Works on Auditing History
No full textPurpose – This research aims to investigate auditing studies, which have an essential place in accounting history, and to reveal its scientific map. Design/methodology/approach – This research investigates audit history studies published in “The Accounting Historians Journal”, “Accounting History Review”, and “Accounting History” journals, which are expert publications of accounting history studies. The research comprises 145 articles published between 1977 and 2021 in three journals. It presents the general view of the audit history studies by examining the audit research in the three leading journals in the history of accounting in terms of volumetric trend, keyword, authorship, subject, research periods, location, and method over the years. Findings – In all three journals, auditing research have shortly after they started to be published. From the 1970s until today, written and published research in English has been reached on the history of audits, 41 in The Accounting Historians Journal, 44 in Accounting History Review, and 60 in Accounting History. The findings obtained from the studies and the examined articles' general characteristics were determined. Discussion – As a result, it is concluded that audit studies do not take up much space in accounting history journals, and the articles are rich in subject variety and keyword diversity; it has been interpreted that the studies should be expanded in terms of place and time frame, and the place and importance of auditing history in accounting should be investigated further