TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7149

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Department: search.filters.department.Izmir Institute of TechnologyLanguage: search.filters.language.en

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  • Article
    Sedde Altında Taşkın Kaynaklı Sızmanın Nümerik Modellenmesi
    (2021) Pulat, Hasan Fırat; Semerci, Aykut; Tayfur, Gökmen
    Taşkın, mühendislik hidrolojisinin en karmaşık sorunlarını meydana getirir ve aşırı taşkın, kentsel alanlar, altyapı, sanayi ve tarım için hayati riskleri içerir. Bu makalenin amacı, Filyos Nehri seddesi üzerinde taşkınların neden olduğu düzensiz akışı incelemektir. Analizlerde sonlu elemanlar yöntemine dayalı sayısal modelleme yapılmıştır. Plaxis 2D'ye bir eklenti modülü olan PlaxFlow, program dahilindeki çeşitli ilgi noktalarında sızıntının zaman değişimi analizi için kullanılır. Seddenin çeşitli ilgi noktalarında çıkış hızı, hidrolik eğim ve doygunluk derecesi incelenmiştir. Ayrıca Filyos seddesinin altındaki farklı zemin türleri için su sızıntısı da incelenmiştir. Borulama meydana geldiğinde ve oluşan kum kaynamasında meydana gelen düzensiz akış analizlerinin sonuçları farklı zemin tipleri için sunulmuştur.
  • Article
    Edible Film Production From Effluents of Potato Industry Incorporated With Origanum Onites Volatile Oils and Changes Its Textural Behaviors Under High Hydrostatic Pressure
    (2021) Evrendilek, Gülsün Akdemir; Bulut, Nurullah; Uzuner, Sibel
    Development and characterization of edible film incorporated with Origanum onites volatile oil from the effluents of potato industry, determination of changes on its textural properties of force and elongation at break (EAB) under high hydrostatic pressure (HHP) in addition to its antimicrobial effect against Escherichia coli O157:H7 and Salmonella Enteritis were prompted. The optimum operational conditions under HHP for maximum force and EAB were achieved with 350 MPa pressure, 8 min operational time, and addition of 45 μL O. onites volatile oil concentration (VOC). Inhibition zones for S. Enteritis and E. coli O157:H7 at the optimum conditions were 1.7 ± 0.109 and 2.386 ± 0.07 cm, respectively. Textural properties of force and EAB of the HHP-processed films ranged from 2.27 ± 0.52 to 5.23 ± 0.79 N, and from 7.47 ± 1.68 to 15.71 ± 0.65 mm, respectively. Thermal transition of the edible film was observed at 86.77°C for 7.19 min. The microscopic observation of the film surfaces shoowed homogenous and translucent structure. The improved textural properties with HHP and VOC revealed that it carries a potential to be used as a food packaging material.
  • Article
    Impact of Pasteurization Process on the Quality and Marination Properties of Onion Juice
    (2020) Kaya, Zehra; Yıldız, Mustafa Kemal; Demir, Hande; Unluturk, Sevcan; Becerikli, İsmail
    This study aims to compare UV-C irradiation and conventional heat treatment to produce pasteurizedonion juice used as a meat marinating agent. The process conditions maximizing the inactivation oftarget microorganism Escherichia coli K-12 were; 0.5 mm sample depth, 30 min irradiation, 7.5mW/cm2 UV incident intensity for UV-C and, 74.5°C and 12 min for heat treatment. Except pH andnon-enzymatic browning index, differences between physicochemical properties of raw, UV-C andheat-treated onion juices were significant. Springiness and chewiness of unmarinated beefsteakswere higher compared to the ones marinated with the fresh and pasteurized onion juice (UV-C andheat). Pasteurization of onion juice (UV-C and heat) did not significantly affect general liking scorescompared to beefsteaks marinated in untreated onion juice.
  • Article
    Fotoğraflar Yoluyla Sosyokültürel Bağlamların Okunması; İzmir’in Erken Cumhuriyet Döneminde Çekilen Kadın Fotoğrafları Vaka Çalışması
    (2020) Günduru, Beliz; Destici, Orkun; Türkmen, Doruk; Yurt, Canberk; Aşıcı, Burçin
    Bireyler, dış görünüşleri aracılığıyla, bulundukları dönemin sosyokültürel, ekonomik ve politik değişimlerini yansıtırlar. Geç Osmanlı Dönemi’nden Cumhuriyet’in ilanına kadar geçen sürede, Türk toplumunda bir dizi modernleşme adımları atılmıştır. Bu süreçte fotoğraf, hem mesleki bir enstrüman hem de yenileşimci bir araç olarak sosyal değişimleri temsil etmesinden dolayı, toplumda kritik bir role sahip olmuştur. Bunun yanı sıra, Kıyafet Reformu ve kadınlara seçme-seçilme hakkının tanınması gibi regülasyonlar ve batı modası, kadın imajına ilham vermiş ve kadınların Türk toplumundaki rolünün yeniden tanımlanmasını sağlamıştır. Bu reformlar kadınlara daha fazla özgüven ve özgürlük sağlamıştır. Bununla birlikte kadınların fotoğraflarda kendini ifade etme şekli değişmiştir. Bu çalışma, İpek Cabadak’ın “Geleceğe Emanet Fotoğraflar” isimli özel fotoğraf koleksiyonundan rastgele seçilen beş kadın fotoğrafının sosyokültürel bağlamda analiz edilmesini hedeflemektedir. Araştırma yöntemi olarak seçilen ikonografik görsel analiz metodu, dönemin sosyal, tarihi ve kültürel olayları doğrultusunda ve İpek Cabadak’ın yol göstericiliği ile uygulanmıştır. Seçilen fotoğraflarda erken Cumhuriyet döneminin moda ipuçlarına, pre-ikonografik veriye ve tarihi gerçekliklere dayalı ikonografik görsel analizler yapılmıştır. Bu analizle, fotoğrafların çekildiği zaman ve mekanlar ile sosyo-kültürel olaylarla ilişkisini tanımlamak amacıyla, Türk kadını, Türk kadınının toplumdaki etkileşimi ve konumu gibi konular hakkında kullanılabilir bilgiler elde edilmiştir. Bu çalışma doğrultusunda, fotoğrafın, tarihsel sosyokültürel çalışmalarda yapılan görsel analizlerde faydalı ve etkili bir araç olduğu sonucuna varılmıştır.
  • Article
    Bir Kinestetik Haptik Cihazın Dinamik Analizi
    (2018) Ceccarellı, Marco; Maaroof, Omar W.; Dede, Mehmet İsmet Can
    Bu makalede R-CUBE mekanizması ve seri küresel bilek mekanizmasını temel alan bir hibrit-yapılı kinestetik haptik cihaz üzerinde durulmuştur. Cihaz noktasal teması kullanıcıya hissettirmesi için tasarlanmıştır. Dolayısı ile, sadece üç-boyutlu kuvvetler kullanıcıya R-CUBE mekanizması üzerinden iletilmiştir. Bu makale, mekanizmanın kabiliyetinin daha iyi anlaşılması ve ilerideki çalışmalarda haptik denetleyicisinde kullanılması için, RCUBE mekanizmasının yarı-statik kuvvet analizini, yerçekimi etkisi telafisi hesaplarını ve dinamik analizini sunmaktadır. Çıkarılan dinamik denklemler kullanılarak haptik uygulama senaryolarında gerekli eyleyici torkları incelenmiştir.
  • Article
    Ai-Assisted Survival Prediction in Colorectal Cancer: a Clinical Decision Support Tool
    (Dokuz Eylul Univ inst Health Sciences, 2024) Misirlioglu, Huseyin Koray; Leblebici, Asim; Calibasi-Kocal, Gizem; Ellidokuz, Hulya; Basbinar, Yasemin
    Purpose: This study was planned to determine the problems and affecting factors that children encounter Purpose: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Accurate survival prediction is crucial for advanced-stage patients to optimize treatment strategies and improve clinical outcomes. This study aimed to develop an artificial intelligence-assisted clinical decision support system (CDSS) for survival prediction in CRC patients using clinical and genomic data from the Cancer Genome Atlas Colon Adenocarcinoma Collection (TCGA-COAD) dataset. Methods: Machine learning algorithms, including C4.5 Decision Tree, Support Vector Machines (SVM), Random Forest, and Naive Bayes, were employed to create survival prediction models. Clinical parameters and genomic data from key pathways, such as glycolysis/gluconeogenesis and mTORC1, were integrated into the models. The models were evaluated based on accuracy and performance. Results: The Random Forest algorithm achieved the highest accuracy (82.3%) when only clinical parameters were used. When clinical data were combined with gene expression data, the model's accuracy increased further. The resulting models were incorporated into a user-friendly web interface, SurvCOCA, for clinical use. Conclusions: This study demonstrates the potential of AI-based tools to improve prognosis predictions in CRC patients. Further research is needed, with larger datasets and additional machine learning algorithms, to enhance clinical decision-making and optimize treatment strategies.
  • Article
    Doha’da Enerji Verimli Bina Kabuğu Tasarımı için Biyomimetik Yaklaşım
    (2024) Nalçakan, Berkay; Koyunbaba, Başak Kundakcı
    Bu çalışmada dünya genelinde artan nüfusa bağlı olarak yapılı çevrenin her geçen gün artan enerji talebine karşılık binaların enerji tüketimini doğrudan etkileyen bina kabuk tasarımları için bir yaklaşım önerilmektedir. Çalışma kapsamında doğadan ilham alan yaklaşımla oluşturulan bina kabuk sisteminin hem tasarım hem de simülasyon süreçleri birlikte ele alınarak enerji verimliliği noktasında iyileştirme hedeflenmektedir. Ekstrem hava koşullarına sahip Doha, Katar'da hayali bir ofis binasının güney cephesinde yer alan ofis birimi için geliştirilen bu kabuk sisteminin tüm mimari entegrasyon süreci ele alınmaktadır. Çalışma boyunca oluşturulan simülasyon çıktıları ile birlikte geliştirilen biyomimetik kabuk tasarımının soğutma yükü ve gün ışığı parametreleri üzerine etkileri analiz edilmektedir. Çalışma sonucunda biyomimetik yaklaşımla oluşturulan bina kabuk sisteminin binayı enerji verimliliği açısından iyileştirdiği gözlemlenmiştir.
  • Article
    Abrasion Behavior of Natural Aggregates and Slags in Turkey Aided by Micro-Deval Test
    (2024) Gökalp, İslam; Uz, Volkan Emre
    The properties of aggregates over their lifetime vary depending on their petrographic origin, procurement and sampling methodologies, regional characteristics and testing procedures. This study was designed to investigate the short and long-term wear properties of aggregates, including slags, using a simple, effective and inexpensive Micro-Deval (MD) test. To accomplish this, ten types of products were obtained from different regions, including natural aggregates and slags of different origin. The aggregates were abraded with different MD drum speeds ranging from 5250 to 52500 in accordance with ASTM D6928 standard. Percentage mass losses (PML) were determined after the treatments to analyze the extent of abrasion caused by short and long term abrasive forces depending on the aggregate type. Scanning electron microscopy (SEM) images of representative aggregates were taken to monitor the effect of abrasion on aggregate microstructure. According to the results, the PML of natural aggregates was observed significantly higher than that of slags, and the PML of slags after certain abrasion treatment tends to be stable, but not for natural ones. Based on regression analyses, a strong relationship between PML for individual aggregates was calculated, but a weak relationship was found based on the origin of the samples and total samples. SEM images taken from the surface of the aggregates confirmed the compatibility of the PML results with the abrasion characteristics showing the current situation.
  • Article
    Impact of Internal Phase Volume on the Physical, Morphological and Mechanical Characteristics of Emulsion Templated Scaffolds
    (2024) Dikici, Betül Aldemir
    Objectives: The high porosity of tissue engineering scaffolds is advantageous as they provide a high degree of infiltration of nutrients, enable cell penetration, and support vascularisation. However, the mechanical strength is also critical for providing structural support to the defect site throughout the regeneration process. In this study, we aimed to establish a relationship between internal phase volume and emulsion-templated scaffolds' physical, morphological and mechanical characteristics. Methods: In this work, tetra methacrylate functionalised polycaprolactone (4PCLMA) polymers were synthesised via ring-opening polymerisation followed by methacrylation. 4PCLMA-based emulsion templated matrices with 60%, 75% and 82% internal phase volumes were fabricated (P60, P75, and P82). These scaffolds' densities, porosities, average pore and window sizes, degree of interconnectivity values, and mechanical properties were investigated. Results: Increasing internal phase volume reduced the density of the foams by almost two-fold. No direct correlation was observed between average pore size and internal phase volume. Both the average window sizes and the degree of interconnectivity values increase with increasing internal phase volume. Compression modulus values are calculated as 0.46±0.04 MPa, 0.23±0.02 MPa and 0.14±0.01 MPa for P60, P75, and P82, respectively. Increasing internal phase volume from 60% to 82% caused a more than 2-fold reduction in the stiffness of the emulsion-templated matrices. Conclusions: Accordingly, by reporting on this experimental framework, we established a relationship between internal phase volume and the physical, morphological and mechanical characteristics of 4PCMA-based scaffolds to precisely engineer these characteristics for specific tissue engineering applications.
  • Article
    Sensitivity Analysis of Wear on Metal-On Bearing Couples Via Verification of Numeric and Analytic Methods
    (2024) Alpkaya, Alican Tuncay; Mihcin, Senay
    Wear mechanism is important since it leads to revisions in Total Hip Replacement (THR) surgeries. Contact pressure plays an important role in wear mechanisms and needs to be investigated in detail to obtain more accurate wear predictions to understand the wear performance of the implant in the design stage. This study proposes a methodology for verification of contact pressure and pressure distribution via numeric and analytic methods to be used in wear calculations. Based on Hertz’s contact theory, the contact pressure and the contact area ae calculated in the analytical method. The results are compared to the numeric method’s results obtained from the finite element method. The linear and volumetric wear rates of bearing couples’ surfaces were estimated by Archard’s wear equation. The effect of design parameters on pressure such as head radius, cup thickness, material combination of bearing couples, coating film material, and film thickness are investigated in this study using the proposed methodology. The minimum error between the analytical and numerical results was 0.24% for 28 mm of head diameter, while the maximum error was 11.79 % for 48- mm of head diameter. The minimum contact pressure values were obtained from 48- mm of head radius at a half contact angle of 190 (degrees) in FEM and Hertz calculations, respectively. The maximum linear wear rate was calculated at 0.0026 mm/Mc at a 1- mm cup thickness, while minimum linear wear rate was 0.0022 mm/Mc at a 10- mm cup thickness in the numeric method. The maximum survival cycles of coating materials rate were 31847 cycles for the Stainless-steel coated cup with 500 μm of coating thickness, while the minimum cycles was 2359 cycles for the Ti64 coated cup surface with 100 μm of coating thickness. It is concluded that the most important design parameters are the cup thickness and the material combinations since they have a significant effect on the contact pressure and the contact area. This study provides a verification methodology for the parametric sensitivity analysis before experimental validations. The methodology utilized in this study could be utilized by designers while optimizing the design parameters to minimize the wear.