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Öğe Effect of Saliva Decontamination Procedures on Shear Bond Strength of a One-step Adhesive System(MEDKNOW PUBLICATIONS & MEDIA PVT LTD, 2017) Ulker, E.; Bilgin, S.; Kahvecioglu, F.; Erkan, A. I.Aim: To evaluate the effect of different saliva decontamination procedures on the shear bond strength of a one-step universal adhesive system (Single Bond T Universal Adhesive, 3M ESPE, St. Paul, MN, USA). Materials and Methods: The occlusal surfaces of 75 human third molars were ground to expose dentin. The teeth were divided into the following groups: Group 1 (control group): Single Bond T Universal Adhesive was applied to the prepared tooth according to the manufacturer's recommendations and light cured; no contamination procedure was performed. Group 2: Bonding, light curing, saliva contamination, and dry. Group 3: Bonding, light curing, saliva contamination, rinse, and dry. Group 4: After the procedure performed in Group 2, reapplication of bonding. Group 5: After the procedure performed in Group 3, reapplication of bonding. Then, composite resins were applied with cylindrical-shaped plastic matrixes and light cured. For shear bond testing, a notch-shaped force transducer apparatus was applied to each specimen at the interface between the tooth and composite until failure occurred. The data were statistically analyzed using one-way ANOVA. Results: One-way ANOVA revealed significant differences in shear bond strength between the control group and experimental Groups 2 and 4 (P < 0.05). No significant difference was found for experimental Groups 3 and 5 when compared to the control group (P > 0.05). Conclusion: The present in vitro study showed that water rinsing is necessary if cured adhesive resin is contaminated with saliva to ensure adequate bond strength.Öğe A new approach for assessing stability of rock slopes considering centroids of weak zones(SHAHROOD UNIV TECHNOLOGY, 2018) Turanboy, A.; Ulker, E.; Kucuksutcu, C. B.The intersection lines between discontinuity surfaces and their intersection points on the visible surfaces of any engineering structure may be the instability indicators. This paper describes a new approach to modelling the intersecting lines and points that would provide the first evaluation of any instability in an engineering structure characterized by the failure modes. In this work, the intersection lines were grouped according to their direction either in the reverse or in the same direction as the dip of the slope. Furthermore, the intersection lines are grouped according to various ranges of the interior friction angle, which can be selected by the users in a computer application developed for this work. The orientation of the intersecting lines and the location of the exposed intersection points are defined and assigned as the scatter points. These exposed points are clustered to determine the centroid locations. The K-means clustering is used in this step. Finally, all these analyses are integrated in a logical order, and the results obtained are used to assess the instabilities on the slope surface. Experiments are carried out on a rock cut along the Konya-Antalya (Turkey) highway, which is composed of limestone, to demonstrate the performance and results of the approach. The locations of the possible failure zones in the critical range of the interior friction angle are defined both visually and numerically along the slope. Experiments show that the proposed method is very useful and easy to implement and yields practical preliminary evaluation results pertaining to instabilities according to the basic failure modes.Öğe Rough set based categorical(INT ASSOC ENGINEERS-IAENG, 2007) Ulker, E.; Siramkaya, E.; Arslan, A.One of the most studied fields in data mining is association rules field and studied on this field more than database communications recently. In existed methods of association rules discovery, studying of objects as an only one category provides deficiency of algorithms which provide finding of categorical associations. Online text documents on internet provide adequate information sources. In this paper, meaningful and important information from text documents on internet have been tried to discover. Firstly, a preprocessing is applied to these data to reduce data with noisy and after that only adequate data are saved to database to use. In the study, relations are discovered based on person-place-event-date categories. In this paper, it is investigated to how the categorical association rules can be discovered using rough sets and presented as an application.Öğe Using the distribution curves to optimize the block exploitation in natural stone quarries(CRC PRESS-TAYLOR & FRANCIS GROUP, 2014) Turanboy, A.; Ulker, E.The geometrical design of optimum cutting is the first task in natural stone quarries. The largest trade blocks (quboits) are the most desired, but they are limited by several geological drawbacks, including one of the most important, discontinuities in rock mass. Rock blocks in mass that formed naturally may range from very small to a few meters with different shapes and orientations. Most trade blocks are chosen and cut from intact rock that bounded discontinuities. Therefore, a discontinuity-based economical analysis should be done in many phases, especially in pre-evaluating deposits and during the cutting operations. There are many modelling methods related to discontinuities. These methods have been used successfully as one of the main tools in many mining and civil engineering applications such as stability, blasting, and fluid flow. Nevertheless, discontinuity-based assessments and economical analyses related to them have not adequately progressed in the natural stone industry. The analyses and assessments in natural stone quarries generally are still done with human perception. Furthermore, it causes the loss of a large amount of natural resources as an inevitable result of low technology. The general aim of this study is to compare the current and optimal conditions of productions in active dimension stone quarries as well as pre-evaluations of natural stone deposits. Therefore, we suggested a new perspective comparing the distribution curves of blocks (polyhedrals and quboits) from in in-situ deposit to the final product. This paper also made several theoretical comments about distribution curves.
