{"title":"Effects of Heat Treatment on Microstructure and Impact Resistance of High Manganese Steels","authors":"Hakan Yildirim, M. E. Erdi̇n, Ali Özgedi̇k","doi":"10.2339/politeknik.1363853","DOIUrl":"https://doi.org/10.2339/politeknik.1363853","url":null,"abstract":"High manganese steels are widely used as wear- and impact-resistant materials in many areas, especially in the mining, construction, cement, and metallurgy sectors, where it is extremely important to be able to work safely in high-stress conditions as well as resistance to abrasion under heavy loading conditions thanks to their unique work-hardening performance. At this point, the carbon and manganese ratio of the material has a considerable influence on the microstructure of the cast part after the heat treatment. Therefore, heat treatment conditions have to be determined appropriately depending on the chemical composition of the material. In this study, heat treatment processes were applied to high manganese steel specimens having GX120MnCr18-2 DIN standard at various austenitizing temperatures between 1030~1100 oC. The specimens were examined under an optical microscope and SEM/EDS analyses were performed. Impact resistance and hardness values of the above-mentioned specimens were measured via the tests performed with TS EN ISO 148-1 and TS EN 130 6508-1 standards, respectively. From these investigations, it was determined that the carbide solubility increased as the austenitizing temperature increased while the impact resistance first increased and then decreased.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139310069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ABSORBSİYONLU SOĞUTMA SİSTEMLERİNDE MİKRO KANALLI ABSORBER VE DESORBERİN SAYISAL OLARAK MODELLENMESİ","authors":"Utku Türkmen, İbrahim Atilgan","doi":"10.2339/politeknik.1341852","DOIUrl":"https://doi.org/10.2339/politeknik.1341852","url":null,"abstract":"Çalışma kapsamında mikro kanallı ve membran tabanlı absorber ve desorber farklı kanal yükseklikleri (0,5mm – 1mm – 1,5mm), farklı eriyik giriş hızları (0,003-0,072 m/s ve 0,0075-0,0125 m/s), farklı eriyik çeşitleri (LiBr-Su, LiBr/LiNO3/LiI/LiCl-Su, [EMIM][OAc]-Su, LiCl-Su) ve farklı kanal tiplerine (düz kanal, içerisinde bölgesel tümsekler içeren kanal, kanal boyunca kavisler içeren kanal) göre optimizasyon çalışması gerçekleştirilmiş ve sonuçlar değerlendirilmiştir. Sonuç olarak eriyik giriş hızları ve kanal yükseklerinde optimum koşullar belirlenmiş ve özellikle [EMIM][OAc]-Su eriyiğinin absorbsiyon oranı ve basınç düşüşü verilerine göre, LiCl-Su eriyiğinin ise desorbsiyon oranı verilerine göre avantajlı olduğu tespit edilmiştir. Bununla birlikte kanal yapısındaki değişikliklerin absorbsiyon oranlarında anlamlı bir artış sağladığı, bununla birlikte basınç düşüşü konusunda negatif etkisi tüm sonuçlarda görülmüştür.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139312501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Roig, S. Alcaraz, K. Gilly, Cristina Bernad, C. Juiz
{"title":"Study on Data Center Network Topologies for Monitoring Data using Edge/Fog Computing","authors":"P. Roig, S. Alcaraz, K. Gilly, Cristina Bernad, C. Juiz","doi":"10.2339/politeknik.1327987","DOIUrl":"https://doi.org/10.2339/politeknik.1327987","url":null,"abstract":"The election of an appropriate data center network topology is key when dealing with surveillance and monitoring processes, such as those devoted to obtaining relevant data for sensor data fusion in any type of remote computing environment so as to perform fault diagnosis and prevention. In this paper, some of the most commonly used topologies to interconnect nodes within a data center bound to edge/fog computing, representing either switch-centric ones or server-centric ones, are reviewed and analyzed from a statistical point of view in order to measure their performance, resulting in server-centric ones doing it better.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139314714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nesrin KOÇ USTALI, Makber Teki̇n, Yavuz Toraman, Fahriye Merdi̇venci̇
{"title":"Küresel Risk Yönetim İndeksi Değerlendirmesi: Gri Tabanlı TOPSİS Yöntemi Uygulaması","authors":"Nesrin KOÇ USTALI, Makber Teki̇n, Yavuz Toraman, Fahriye Merdi̇venci̇","doi":"10.2339/politeknik.1292856","DOIUrl":"https://doi.org/10.2339/politeknik.1292856","url":null,"abstract":"Avrupa Komisyonu’nun iş birliği doğrultusunda oluşturulan Küresel Risk Yönetim İndeksi (INFORM), insani krizler ve afetlerle ilgili karar alma süreçlerini desteklemek üzere analitik bulgular geliştirerek ülkeler için afet yönetim döngüsü aşamalarında karar vermeye yardımcı olmaktadır. Ülkelerin afet yönetiminde başarılı olmasına destek olabilecek bu indeks, sınırlı sayıda çalışmada ele alınmış ve ampirik olarak yeterli düzeyde test edilmemiştir. Bu çalışma, INFORM metodolojisinin geliştirilmesi için zaman boyutunu dikkate alan bir Çok Kriterli Karar Verme Yöntemi (ÇKKV) ile yeni bir sıralama oluşturmayı amaçlamaktadır. Çalışmada, 19 ülke değerlendirme kapsamına alınmıştır. Bu ülkelere ait veri seti, Avrupa Komisyonu’nun 2015-2023 yıllarında yayınladığı INFORM raporlarından elde edilmiştir. Çalışmada önerilen model ile 9 yıllık risk yönetim performansı analiz edilmiştir. Ayrıca zaman boyutunun değerlendirme aşamalarına dahil edilmesi sonucunda ülkelere ait yeni bir risk yönetim performansı sıralaması oluşturulmuştur. TOPSIS-G yaklaşımıyla elde edilen ülke sıralamalarıyla INFORM sıralamaları, Spearman ve Kendall Tau-b non-parametrik korelasyonları kullanılarak karşılaştırılmıştır. Sonuçlar iki sıralama arasında yüksek korelasyon olduğunu göstermektedir. Risk yönetim performansı sıralamasına göre çalışmada ele alınan ülkeler için afet yönetim aşamalarında iyileştirme yapması gereken alanlara dikkat çekilmiş ve önerilerde bulunulmuştur.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139322583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aybaba Hançerli̇oğullari, Şeref Turhan, Arif Baştuğ, Y. G. A. Madee
{"title":"Türkiye'deki Ocaklardan Alınan Doğal Kil Mineral Örneklerinde Ağır Metal Konsantrasyonlarının Belirlenmesi","authors":"Aybaba Hançerli̇oğullari, Şeref Turhan, Arif Baştuğ, Y. G. A. Madee","doi":"10.2339/politeknik.1356125","DOIUrl":"https://doi.org/10.2339/politeknik.1356125","url":null,"abstract":"Environmental pollution of heavy metals is increasingly becoming a problem and has become of great concern due to the adverse effects it is causing around the world. Today, various chemical, biological, and physical pollutants arising as a result of rapidpopulation growth, industrialization, and excessive mining activities have become a major problem that adversely affects people, animals, plants, organisms, and ecosystems all over the world. Sepiolite is a clay mineral containing hydrated magnesium silicate and widely used in construction, agriculture, food, fertilizer, pharmaceutical, detergent, cosmetics, paint, paper, etc. The average concentrations of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Zr, Cd, Sn, Ba and Pb analyzed in sepiolite samples collected from three quarries (Polatlı, Beylikova, and Sivrihisar) located in the Central Anatolian Region of Turkey using EDXRF spectroscopy were found as 5456.5, 361.0, 42.0, 15.5, 65.2, 3831.5, 8.6, 23.7, 7.8, 11.8, 5.3, 13.7, 1183.2, 25.3, 3.7, 7.2, 131.9 and 5.3 mg/kg, respectively. The average enrichment factor values of V, Cr, Co, Ni, Cu, Zn, As, Sr, Cd, Sn, Ba, and Pb indicated minimal to extremely high enrichment in sepiolite. The values of non-carcinogenic risk index and cancer risk estimated to evaluate potentially health risks caused by PTEs in sepiolite samples were within the acceptable limit and the safe range except for the Beylikova quarry.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139336436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diagnosis of Glaucoma and Cataract Disease with Deep Learning Models","authors":"Mehmet Tümay, Zafer Civelek, Mustafa Teke","doi":"10.2339/politeknik.1348143","DOIUrl":"https://doi.org/10.2339/politeknik.1348143","url":null,"abstract":"Göz, insanoğlunun en önemli organlarından biri olmasına rağmen birçok hastalığa da maruz kalabilmektedir. Bu hastalıklardan bazılarına toplumda sıklıkla rastlanmaktadır. Bunlardan ikisi katarakt ve glakom olarak bilinen çok önemli göz hastalıklarıdır. Evrişimli Sinir Ağları (ESA), bu hastalıkların erken tanı ve uzman teşhisine yardımcı olmak için kullanılabilir. Bu çalışmada derin öğrenme yöntemlerinden biri olan Evrişimli Sinir Ağları kullanılarak katarakt, glakom ve normal göz dibi görüntüleri sınıflandırılmıştır. Eğitilmiş Ağlar kullanılarak Googlenet, Densenet-201, Xception ve Inception-V3 ağlarının performansları karşılaştırılmıştır. Her ağ için adam, rmsprop ve sgdm optimizasyon yöntemleri uygulanmıştır. Bu çalışma, datasetteki 262 Katarakt, 200 Glakom ve 2816 normal göz dibi görüntüsü kullanılarak yapılmıştır. Görüntüler, yeniden boyutlandırma, arka planı kaldırma, rastgele döndürme ve yeniden boyutlandırma ile önceden işlenmiştir. Matlab ortamında yapılan simülasyonlar sonucunda, diğer ağlara göre en iyi sonuçlar rmsprop optimizasyonlu Xception ağ mimarisi ile elde edilmiştir.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139339138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tuncer Demi̇rel, S. Yağmur, Yunus Kayır, Abdullah Kurt
{"title":"Investigation of Thrust Force, Torque and Chip Formation in Tapping Threading by Finite Element Method","authors":"Tuncer Demi̇rel, S. Yağmur, Yunus Kayır, Abdullah Kurt","doi":"10.2339/politeknik.1342932","DOIUrl":"https://doi.org/10.2339/politeknik.1342932","url":null,"abstract":"Threading with taps is a method frequently used in machining. Since this process takes place in a closed area due to its nature, some difficulties are encountered. In this study, the results of a previous experimental work were compared with the results of a simulation program. In the experimental work, the tapping process were performed by using M10 taps with three different geometries for the drilled holes on AISI 1050 material. Tapping operations were carried out with uncoated and TiN coated HSS tools. For the simulatin program, the 3D CAD models of the tested taps were created by reverse engineering method and then imported into a simulation program, called Third Wave AdvantEdge program. The CAD models were evaluated by Third Wave AdvantEdge program based the finite element method. The thrust force, torque, chip formation occurring during the threading process were examined. It was concluded that the simulation and the experimental results were quite compatible.","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139341327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Yapay Sinir Ağları Kullanılarak Pediatrik Akciğer Röntgen Görüntülerinden Pnömoni Tespiti","authors":"Özgür Dündar, Sabri Koçer","doi":"10.2339/politeknik.1332211","DOIUrl":"https://doi.org/10.2339/politeknik.1332211","url":null,"abstract":"Pneumonia Detection from Pediatric Lung X-Ray Images Using Artificial Neural Networks ABSTRACT Studies on medical imaging have grown significantly in recent years. Doctors have a crucial convenience for diagnosis thanks to semi- or fully automatic region recognition in medical imaging. It is crucial to support treatment without a specialist doctor, particularly in those nations where there is a dearth of such medical professionals. The little air sacs known as alveoli are most impacted by pneumonia, a lung inflammation. A key component of providing the right therapy conditions to heal patients and reduce harm while eradicating inflammation is early detection and precise diagnosis. Noise and blurring in patient photos obtained from X-ray machines are cleaned using deep learning algorithms and image processing techniques, and they are very helpful in. In this study, we studied chest X-ray images of pediatric patients with pneumonia and healthy individuals. XGBoost (eXtreme gradient boosting) is an innovative machine learning algorithm based on decision tree and using gradient boosting in its computations. It achieved 97.01% success with high classification performance. Keywords: Medical imaging, Machine learning, Pediatric Chest X-ray","PeriodicalId":16884,"journal":{"name":"Journal of Polytechnic","volume":"139 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}