Öksüz Yayınlar Koleksiyonu
Bu koleksiyon için kalıcı URI
Güncel Gönderiler
Öğe Tool Wear Mechanism in Interrupted Cutting Conditions(Taylor & Francis Inc, 2009) Sayit, Ercan; Aslantaş, Kubilay; Çiçek, AdemIn this study the machinability of ductile iron having ferritic structure was examined in interrupted cutting conditions. For this purpose, cylindrical samples with 1, 2, and 4 axial slots were prepared. Uncoated cemented carbide cutting tool was used in this work. Two different cutting speeds, feed rate and depth of cut were chosen as cutting parameters. According to results, the number of slots seriously affects the tool wear. Increasing the number of slots results in a decrease in the dimension of chip. Another result observed during the tool wear experiments was that increasing the number of slots results in increase of flank wear. However, the cutting tool wears out rapidly at higher feed rate or depth of cut when one or two slotted workpiece are used. Scanning Electron Microscope (SEM) and Energy Dispersive X-ray microanalysis (EDX) of the worn tools showed that abrasive, adhesion and oxidation wear mechanisms are predominant in the machining of continuous and interrupted cutting of ductile iron.Öğe Structure and thermal decomposition of mu-1,1-azido bridged dinuclear Fe(III) complexes(Oldenbourg Verlag, 2007) Ercan, Filiz; Ateş, B. Meltem; Aksu, Levent; Sözeri, Hüseyin; Ercan, İsmail; Atakol, OrhanFe(III) complexes were prepared by the reaction of two different ONNO type Schiff bases N,N'-bis (salicylidene)-1,3-propanediamine (LH2) and N,N'-bis (salicylidene)-2,2'-dimethyl-1,3-propane diamine (LDMH2) in N-3(-) containing medium. The X-ray diffraction studies revealed that the complexes are of dinuclear type connected with mu-1,1-azido bridges. It was observed from the thermogravimetric analyses of the complexes that the azide group decomposed around 200 degrees C with exothermic reaction. This exothermic decomposition did not affect the rest of the molecule. Following the decomposition of the azide group the remainder of the molecule decomposed with carbonization process. It was seen that the molecule decomposed into Fe2O3 above 650 degrees C in oxygen containing medium. [FeLDMN3](2) complex was found to have N4O2 distorted octahedral sphere with Fe...Fe distance of 3.414 angstrom.Öğe BDT ortamında farklı ölçeklerde tasarlanan katı modellerin ölçekleme değerlendirmesi(2008) Çiçek, AdemBu çalışmada, (Bilgisayar Destekli Tasarım) BDT ortamında farklı ölçeklerde tasarlanan katı modeller arasında ölçekleme oranını tespit etmek için bir yaklaşım geliştirilmiştir. Yaklaşıma girdi olarak katı modellerin STEP "Standard for the Exchange of Product Data Model" veri dönüşüm formatı kullanılmıştır. BDT ortamında tasarlanan katı modellerin otomatik STEP dönüşümü yapılmakta ve daha sonra STEP dosyası değerlendirilerek, bu dosya yüz-kenar ilişki matrisine dönüştürülmektedir. Yeni tasarımın matrisine uyan veritabanından bir matris elde edilerek bu iki matris arasında boyutsal olmayan bir benzerlik değerlendirmesi yapılmaktadır. İki matriste temsil edilen yüzey komşuluk ilişkileri ve boyutsal olmayan nitelikler arasında tam bir eşleme var ise, parçalar arasında ölçekleme değerlendirmesi yapılmaktadır. Ölçekleme değerlendirmesinde, iki matrisin boyutsal nitelikleri arasında bir oran aranmaktadır. Bu oran var ise yaklaşım iki parça arasında ölçekleme oranı hesaplamaktadır.Öğe Küçük ölçekli mobilya üstyüzey işlemleri atelyelerinin yapısal sorunları ve çözüm önerileri(2009) Sönmez, Abdullah; Budakçı, Mehmet; Gengörü, Tahsin; Arslan, Ali RızaBu araştırmada, küçük ölçekli mobilya üstyüzey işlemleri atelyelerinin kuruluş problemleri ve işletmelerin üretim sürecinde karşılaştığı yapısal sorunlar belirlenmeye çalışılmıştır. Araştırma kapsamında, mobilya endüstrisindeki küçük ölçekli üstyüzey işlemleri atelyelerinden Ankara, İstanbul ve Bursa illerinde faaliyet gösteren toplam 50 işletme yöneticisi ve çalışanları ile yüz yüze görüşülerek anket çalışması ve röportaj yapılmış, gözlem sonuçları elde edilmiştir. Araştırma sonuçlarına göre, mobilya işletmelerine ait üstyüzey atelye binası ile ilgili olarak; alan yetersizliği, taşıma, aydınlatma, ısıtma, havalandırma, atelye içinde oluşan veya dış kaynaklı toz, üretim süreciyle ilgili olarak; ekonomik yetersizlik, teknolojik donanım eksikliği, kalifiye eleman bulamama, çalışanlarla ilgili olarak ise; çalışanların sağlığına ve kişisel haklarına yönelik sorunlar olduğu tespit edilmiştir.Öğe Step based geometric and topological similarity assessment of mechanical parts(2007) Çiçek, AdemIn this paper, an approach has been developed to assess geometric and topological similarity between 3D mechanical parts using their face-edge relation matrices. The approach relies on the STEP (Standard for the Exchange of Product Data Model) graphic standard to obtain the geometric and topological data belonging to parts designed in a CAD system. The CAD model of any part is automatically translated into a STEP file and entities represented in the STEP file of it are mapped into face-edge relation matrix. Face-edge relation matrix is a square matrix and sized according to number of faces on a part. In the similarity assessment stage, the closest matrix in the database corresponding to matrix of the new part is retrieved and matched as matrix of the candidate part. Similarity factor between the new and candidate parts is calculated with respect to the matched faces and total faces in both matrices. Similarity assessment is useful for many CAD/CAM applications such as especially variant process planning, cost estimation and group technology. The algorithm has been applied to some real parts to demonstrate its efficiency and capability. © Association for Scientific Research.Öğe Determining amount of bituminous effects on asphalt concrete strength with artificial intelligence and statistical analysis methods(2011) Serin, Sercan; Morova, Nihat; Terzi, Serdal; Sargın, ŞebnemIn this study, an experimental study has been conducted to determine compressive strength of asphalt concrete. The scope of study by preparing 45 Marshall samples Marshall stability experiment was conducted and compressive strength of asphalt concrete was determined. Compressive strength of asphalt concrete as depending on bituminous amount prediction models were developed by using obtained experiment results. Compressive strength of asphalt concrete values as depending on bituminous amount have been estimated on prediction models developed with regression analyses and Artificial Neural Network (ANN) Methods. Results obtained from models were compared with experiment results. Prediction performances of developed models were evaluated as compared. As a result it was determined that possible to estimate the compressive strength of asphalt concrete as depending on bituminous amount with developed ANN model and that ANN model was more successful than regression model for estimating the compressive strength of asphalt concrete. © 2011 IEEE.
