Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 11Citation - Scopus: 12Cement Based Strain Sensor: a Step To Smart Concrete(Foundation Cement, Lime, Concrete, 2011) Teomete, Egemen; Erdem, Tahir KemalAccording to a report published in USA, 30% of the bridges in USA were found to be structurally de cient while concrete infrastructures have a state of material deterioration before the design life is reached (1). Earthquakes, material degradations and other environmental effects decrease the performance of the structures. The assessment of structures by structural health monitoring is very important to protect the lives of people. The best decision about a damaged structure after an earthquake can be made by use of structural tests and structural health monitoring. Structural tests and structural health monitoring are important steps in the decision making of asset management for maintenance and repair of infrastructures. The classical sensors (strain gauges, piezo-electric sensors) have low durability, low sensitivity and high cost. The low durability of classical sensors disables long term measurement while their high cost limits the amount of sensors that can be used (2). The addition of carbon ber to cement based material decreases the electrical resistance of the material. By application of load, the electrical resistance of the material changes (3-5).Article Citation - WoS: 1Citation - Scopus: 1Estimation of Mechanical Properties of Limestone Using Regression Analyses and Ann(Foundation Cement, Lime, Concrete, 2012) Teomete, Egemen; Tayfur, Gökmen; Aktaş, EnginEstimation of mechanical properties of rocks is important for researchers and field engineers working in cement and concrete industry. Limestone is used in cement production. In this study, Schmidt hammer, ultrasonic pulse velocity, porosity, uniaxial compression and indirect tension tests were conducted on limestone obtained from a historical structure. Regression analyses were used to develop models relating mechanical properties of limestone. Artificial Neural Network (ANN) was performed to determine the mechanical properties. The performance of regression models and ANN were compared by existing models in the literature. The results showed that the regression models and ANN yield satisfactory performance with minimum error. The regression models between tensile strength and wave velocity, tensile strength and porosity, wave velocity and porosity have been developed for the first time in literature. The ANN is used for the first time to estimate the mechanical properties of limestone. The use of separate training and testing sets in the regression analyses of mechanical properties of limestone is conducted for the first time. The models developed in this study can be used by researchers and field engineers to relate the mechanical properties of limestone.Conference Object Citation - WoS: 21Citation - Scopus: 26Investigation of Long Waviness Induced by the Wire Saw Process(SAGE Publications Inc., 2011) Teomete, EgemenIn the photovoltaic and semiconductor industries silicon wafers are sliced using the wire saw process. This process is also used to machine almost all kinds of brittle materials where high yield and low surface damage is desired. The wire saw process induces roughness and long waviness on the cut surface. These defects have to be removed by post-process techniques including grinding and lapping, which increases costs. The present study investigated the long waviness induced by the wire saw process. An analytical model for long waviness generation has been developed. Experimental work was conducted with different process parameters. The analytical model is capable of explaining the long waviness generation observed in experimental work. Process design recommendations with minimal waviness and high efficiency are presented.Article Citation - WoS: 11Citation - Scopus: 12Effect of Process Parameters on Surface Quality for Wire Saw Cutting of Alumina Ceramic(Gazi Üniversitesi, 2011) Teomete, EgemenSilicon wafers are sliced using wire saw in micro electronics and photo voltaic industries. Wire saw process occupies a great portion of silicon wafer production cost which affects the market directly. The process is also used to cut ceramics, concrete and rocks in civil engineering. The high cost of the process motivates researchers to develop models that will relate the process efficiency and quality with process parameters. In this study, an experimental parametric study was conducted to investigate the effect of process parameters on the wire bow angle, distributed wire load and surface roughness in wire saw cutting of alumina ceramic. The material removal and surface damage formation mechanisms are identified. Process design recommendations for increasing efficiency of the process while keeping the surface roughness constant, are presented. The surface roughness increases with increasing feed rate, decreases with wire speed and is independent of wire tension. The material is removed by trans-granular failure of the grains while inter-granular fractures of the grains affect the surface quality.Article Citation - WoS: 9Citation - Scopus: 12Structural Analyses and Assessment of Historical Kamanlı Mosque in Izmir, Turkey(American Society of Civil Engineers (ASCE), 2010) Teomete, Egemen; Aktaş, EnginHistorical structures are one of the most precious pieces of cultural accumulation. In this study, an interdisciplinary work was conducted to assess the structural condition of a historical masonry structure, Urla Kamanl Mosque in zmir, Turkey. The structure is a member of group of structures, Yahi Bey Complex, which includes a Turkish bath, a tomb, two fountains, and a primary school. The structure dates back to early 14th century to mid-15th century. History investigation, measurement survey, long-term settlement, and moisture observations were conducted. Nondestructive and destructive material tests were performed on stone, brick, and mortar. 3D finite-element model of the structure was used to investigate the critical locations of the structure under its self-weight, seismic load, and settlement load. Linear elastic and nonlinear settlement analyses were conducted to investigate the reason for massive cracks challenging the structural integrity. © 2010 ASCE.