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Effects of Nigella sativa and human parathyroid hormone on bone mass and strength in diabetic rats

Altan M.F.

Article | 2007 | Biological Trace Element Research116 ( 3 ) , pp.321 - 328

Osteoporosis is a major complication in patients with diabetes mellitus (DM), particularly in those with insulin dependency. Recently, many therapeutic effects of Nigella sativa L. (NS) extracts have been exhibited such as anti-inflammatory, antitumor, and antidiabetic with clinical and experimental studies. Mechanical strength in the femur and vertebrae increases with human parathyroid hormone (hPTH) treatment. The aim of the present study was to test the hypothesis that combined treatment with NS and hPTH is more effective than treatment with NS or hPTH alone in improving bone mass, connectivity, and biomechanical behavior using t . . .he finite element method (FEM) in insulin-dependent diabetic rats. In the mechanical analysis, five rat bones (control, diabetic diabetic NS treated, diabetic hPTH treated, and diabetic NS + hPTH treated) have been studied for bending analysis using the finite element analysis program ANSYS. Combined treatment of NS and hPTH was more effective on bone histomorphometry and mechanical strength than treatment with NS or hPTH alone for streptozotocin-induced diabetic osteopenia, which notably decreased bone volume. © Copyright 2007 by Humana Press Inc. All rights of any nature, whatsoever, reserved Daha fazlası Daha az

Gas detonation forming process and modeling for efficient spring-back prediction

Yasar M.

Article | 2004 | Journal of Materials Processing Technology150 ( 3 ) , pp.270 - 279

Aluminum cylindrical cups are formed with gas detonation forming technology and finite element modeling of aluminum cylindrical cup production with the detonation forming technology is performed. The forming process simulation is carried out in two-step analysis. 2D and 3D computational models are constructed with both explicit and implicit dynamic analyses are performed. The effects of detonation pressure and die design parameters also are investigated. The thickness distribution and deformed geometry of the cups are compared with the experimentally determined values. The spring-back predictions based on the explicit and implicit m . . .ethods are criticized in terms of deformed shape accuracy and elapsed time. © 2004 Elsevier B.V. All rights reserved Daha fazlası Daha az

Finite element analysis of heat treated wood filled styrene maleic anhydride (Sma) copolymer composites [Analiza kompozita od kopolimera stirena i anhidrida maleinske kiseline (Sma) punjenih pregrijanim drvom metodom konacnih elemenata]

Zor M. | Kartal M.E. | Gardner D.J.

Article | 2019 | Drvna Industrija70 ( 1 ) , pp.43 - 49

The computer aided three dimensional static analyses of the specimens was done by using the Finite Element Method (FEM) and obtained data was compared with actual test data. The aim of this study is to compare the deformation/stress analyses with FEM analysis results of styrene maleic anhydride (SMA) copolymer composites. The heat treated wood/SMA copolymer composites were produced from different loadings (from 10 to 30 wt. %) of heat treated and untreated eastern white pine wood flours (Pinus strobus L.). All formulations of wood flour/SMA copolymer composites were produced by melt compounding through injection molding. The deforma . . .tion/stress results obtained from the experimental solutions are very close to the results obtained from the numerical solutions (SAP2000 V17). As a result, it can be said that it is beneficial to use the FEM in the engineering design approach after the data obtained by the experimental solutions as meaningful values after application of the FEM. © 2019, Journal Drvna Industrija. All rights reserved Daha fazlası Daha az

Near-fault ground motion effects on the nonlinear response of dam-reservoir-foundation systems

Bayraktar A. | Altunişik A.C. | Sevim B. | Kartal M.E. | Türker T.

Article | 2008 | Structural Engineering and Mechanics28 ( 4 ) , pp.411 - 442

Ground motions in near source region of large crustal earthquakes are significantly affected by rupture directivity and tectonic fling. These effects are the strongest at longer periods and they can have a significant impact on Engineering Structures. In this paper, it is aimed to determine near-fault ground motion effects on the nonlinear response of dams including dam-reservoir-foundation interaction. Four different types of dam, which are gravity, arch, concrete faced rockfill and clay core rockfill dams, are selected to investigate the near-fault ground motion effects on dam responses. The behavior of reservoir is taken into acc . . .ount by using Lagrangian approach. Strong ground motion records of Duzce (1999), Northridge (1994) and Erzincan (1992) earthquakes are selected for the analyses. Displacements, maximum and minimum principal stresses are determined by using the finite element method. The displacements and principal stresses obtained from the four different dam types subjected to these near-fault strong-ground motions are compared with each other. It is seen from the results that near-fault ground motions have different impacts on the dam types Daha fazlası Daha az

Comparison of near- and far-fault ground motion effect on the nonlinear response of dam-reservoir-foundation systems

Bayraktar A. | Altunişik A.C. | Sevim B. | Kartal M.E. | Türker T. | Bilici Y.

Article | 2009 | Nonlinear Dynamics58 ( 4 ) , pp.655 - 673

In this paper, it is aimed to compare the near- and far-fault ground motion effects on the nonlinear dynamic response of dams including dam-reservoir-foundation interaction. Two different types of dams, which are concrete arch and concrete faced rockfill dams, are selected to investigate the near- and far-fault ground motion effects on the dam responses. The behavior of reservoir water is taken into account using Lagrangian approach. The Drucker-Prager material model is employed in nonlinear analyses. Near and far-fault strong ground motion records, which have approximately identical peak ground accelerations, of Loma Prieta (1989) . . .earthquake are selected for the analyses. Displacements, maximum and minimum principal stresses are determined using the finite element method. The displacements and principal stresses obtained from the analyses of dams subjected to each fault effect are compared with each other. It is clearly seen that there is more seismic demand on displacements and stresses when the dam is subjected to near-fault ground motion. © 2009 Springer Science+Business Media B.V Daha fazlası Daha az

Asynchronous seismic analysis of concrete-faced rockfill dams including dam-reservoir interaction

Bayraktar A. | Haciefendioglu K. | Muvafik M.

Article | 2005 | Canadian Journal of Civil Engineering32 ( 5 ) , pp.940 - 947

Seismic response of concrete-faced rockfill (CFR) dams subjected to asynchronous base excitation is determined by considering dam-reservoir interaction. The equations of motion of the coupled system are obtained using the Lagrangian approach, and the surface sloshing motion is included in the finite element formulation. Torul dam constructed in the city, Gumushane, Turkey, is selected as a numerical example, and its material properties are considered in the analysis. The dam-reservoir interaction system is modelled using the Lagrangian (displacement-based) fluid and solid-quadrilateral-isoparametric finite elements. The east-west co . . .mponent of Erzincan earthquake, which occurred on 13 March 1992, recorded near the region of the dam is used as a ground motion. Propagation velocities of the seismic wave are chosen as 1000 m/s, 3000 m/s, and infinite. Stresses are calculated for empty and full reservoir cases and compared with each other. © 2005 NRC Canada Daha fazlası Daha az

Finite element analysis of wood materials [Analiza drvnog materijala metodom konacnih elemenata]

Tankut N. | Tankut A.N. | Zor M.

Review | 2014 | Drvna Industrija65 ( 2 ) , pp.159 - 171

Continuous quality and reliability improvement of computers as well as their widespread application in design of furniture industry encourage the elaboration of optimization algorithms of furniture constructions, in which rigidity characteristics of the applied joints would be taken under consideration. In the last four decades, the finite element method, FEM, has become the dominant technique used for analyzing physical phenomena in the field of structural, solid and fluid mechanics as well as for the solution of field problems. This paper gives a bibliographical review of the FEM applied in the analysis of furniture products const . . .ructed with wood. The following topics are included: Wood as a furniture construction material and its mechanical properties. It is, therefore, reasonable to replace statistical methods of furniture optimization, which have been applied so far, by gradient methods which allow obtaining much more precise results Daha fazlası Daha az

6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve çerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.

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