University of Tabriz

About: University of Tabriz is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Population & Nanocomposite. The organization has 12141 authors who have published 20976 publications receiving 313982 citations.

Fabrication and characterization of chitosan–gelatin/nanohydroxyapatite–polyaniline composite with potential application in tissue engineering scaffolds

Abstract: In this study to further improve surface characteristics of tissue engineering scaffolds, a novel composite based on chitosan–gelatin/nanohydroxyapatite–polyaniline (CS-Gel/nHA-PANI) was prepared by blending the synthesized nHA and PANI with chitosan and gelatin solution followed by lyophilization technique. The prepared composite scaffold was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. The effects of nHA and PANI on the physicochemical properties of the scaffold including swelling ratio, density, biodegradation, biomineralization, and mechanical behavior were investigated. The composite scaffold was highly porous with the mean pore size of 200 μm. Compared with CS-Gel and CS-Gel/nHA scaffolds, the CS-Gel/nHA-PANI scaffold exhibited lower degradation rate and higher biomineralization and mechanical strength. Preliminary evaluation of the biocompatibility and cytotoxicity of the CS-Gel/nHA-PANI composite scaffold was performed...

A multi-stage particle swarm for optimum design of truss structures

Abstract: The contribution of this study is to propose a multi-stage particle swarm optimization (MSPSO) for structural optimization. In this paper, three auxiliary improving mechanisms are added to the standard particle swarm optimization (PSO) in order to enhance its efficiency and reliability dealing with optimum design of truss structures. These mechanisms effectively accelerate the convergence rate of the PSO and also make it robust to attain better optimum solutions during various runs of the algorithm. The effectiveness of the MSPSO is illustrated by several benchmark structural optimization problems. Results demonstrate the efficiency and robustness of the proposed MSPSO algorithm compared to the standard version of the PSO.

Film cooling effectiveness from trenched shaped and compound holes

Abstract: This paper presents a comparative-numerical investigation on film cooling from a row of simple and compound-angle holes injected at 35° on a flat plate with four film cooling configurations: (1) cylindrical film hole; (2) 15° forward diffused film hole; (3) trenched cylindrical film hole; (4) trenched 15° forward-diffused film hole. All simulations are at fixed density ratio of 1.6, blowing ratio of 1.25, length-to-diameter L/D = 4 and pitch-to-diameter ratio of 3.0. The effect of length-to-diameter ratio on film cooling has been also investigated using L/D in the range of 1–8. Computational solutions of the steady, Reynolds-averaged Navier–Stokes equations have been obtained using a finite volume method. It has been found that the shape of the hole and the trenched holes can significantly affect the film cooling flow over the protected surface. Further, it has been shown that the film cooling effectiveness by trenched shaped holes is higher than all other configurations both in spanwise and streamwise specially downstream of the injection. Also, a trenched compound angle injection shaped hole produces much higher film cooling protection than the other configurations investigated in the present paper. The length-to-diameter ratio of trenched holes was found to have a significant effect on film cooling effectiveness and the spread of the coolant jets.