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Sahinbey, Turkey

Gesoglu M.,University of Gaziantep | Guneyisi E.,University of Gaziantep | Ali B.,University of Gaziantep | Mermerdas K.,Hasan Kalyoncu University
Construction and Building Materials | Year: 2013

In this paper, effect of steam and water curing on the compressive strength development and transport properties such as water sorptivity, rapid chloride ion permeability, and gas permeability of concretes containing various volumes of lightweight fly ash aggregate (LWA) were investigated. In production of concrete, a fixed amount of lightweight coarse (LWCA) aggregate plus varying amounts of lightweight fine aggregate (LWFA) were used. Utilization of LWFA was achieved by volumetric substitution of fine aggregate with five different replacement levels namely, 0%, 25%, 50%, 75%, and 100%. Therefore, five different concrete mixtures were produced for this experimental study. The produced concretes were divided into two parts one of which was initially steam cured while the other was directly exposed to water curing. After initial steam curing regime, the steam cured (SC) concretes were also transferred to water until testing Mechanical properties of concretes were monitored through compressive strength development over 56 days, while transport properties were measured by means of water sorptivity, gas permeability and rapid chloride permeability tests conducted at 28 and 56 days. © 2013 Published by Elsevier Ltd. All rights reserved.

Gorczyca T.W.,Western Michigan University | Hasoglu M.F.,Hasan Kalyoncu University | Manson S.T.,Georgia State University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

It is demonstrated that the effect of a static cage potential on the photoionization of endohedrally enclosed atoms can be incorporated into standard R-matrix calculations using one of two independent methods. For photoionization processes occurring entirely within the fullerene, the outer-region solutions can be modified by the additional cage potential to yield phase-shifted Coulomb functions that are matched to the inner-region R matrix. Alternatively, if the cage potential is contained within the R-matrix "box," it can be directly incorporated into the formalism via simple one-electron integral contributions to the Hamiltonian, yielding a modified R matrix. Both methods are applied to the photoionization of Xe@C 60 in the vicinity of the giant 4d→εf shape resonance and are found to be in excellent agreement with each other. © 2012 American Physical Society.

Nassani D.E.,Hasan Kalyoncu University
International Journal of Steel Structures | Year: 2014

This paper reports the results of a study conducted to investigate the behaviour of steel cap plate connections. In the analysis and design, connections are characterized as either rigid or pinned and between these two extremities lies the actual behaviour of steel frame connections, which is semi-rigid. This classification is characterized by the nonlinear moment-rotation relationship which must be incorporated in the analysis. A cap plate connection is widely used in industrial steel frames for its advantages over other types of building connections, but the response of such a connection has not sufficiently been experimentally determined. In this research, the behaviour of cap plate connections was studied by testing four full-scale connections. Experimental results obtained would add valuable information to the available test data concerning steel connections since sparse data is available in the literature for this type of connection. Mathematical and numerical models were used to analyze the cap plate connection and close correlations were found between these models and the experimental results. © 2014, Korean Society of Steel Construction and Springer-Verlag Berlin Heidelberg.

Abdul Hafez A.H.,Hasan Kalyoncu University
Control Engineering and Applied Informatics | Year: 2014

This paper presents a new stable hybrid visual servo controller to complete the task of robot arm positioning. Our method is generic hybrid method and superior to the state of the art. The objective function is designed to include the full but weighted 2D and 3D available information. The positioning task has been formulated as a minimization problem. Here, each of the 2D and 3D error functions is used to control the six degrees of freedom. The importance weights are computed to satisfy a set of constraints defined by the visual servoing process. Stability analysis is also presented for the proposed control law. The experimental evaluation is done in order to show the enhanced performance of the visual servoing process. Simulation results show that this method provides an efficient solution to the camera retreat and features visibility problems. Performance of the visual servoing system is evaluated by its ability to keep features visible in the image and the Cartesian trajectory within the robot workspace during the process.

Cabalar A.F.,University of Gaziantep | Mustafa W.S.,Hasan Kalyoncu University
Engineering Geology | Year: 2015

Fall cone tests were performed on clay-sand mixtures to investigate the variation of liquid limit with sand content and the link between undrained shear strength and water content for various sand contents in the mixtures. Five different particle gradations (4.75-0.075. mm, 4.75-2.0. mm, 1.18-0.6. mm, 0.6-0.075. mm, and 0.425-0.3. mm) of sands having distinct shapes (rounded and angular) were added to a low plasticity clay with mixture ratios of 0%, 10%, 20%, 30%, 40%, and 50%. Data of the clay-sand mixtures showed that the depth of cone penetration against water content relationship is about linear. The liquid limit estimates of the mixtures were measured to be slightly affected by the gradation and shape of the grains in the range of sand contents employed. The obtained results indicated a decrease of undrained shear strength with an increase in the amount of sand. The use of rounded sands in a clay matrix leads to the development of higher undrained shear strength values, on which gradation of the sands has no effect. © 2015 Published by Elsevier B.V.

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