The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
K. L. Narasimhan - One of the best experts on this subject based on the ideXlab platform.
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Experimental studies on Bursting Pressure of thin-walled flow formed Pressure vessels
Journal of Materials Processing Technology, 2002Co-Authors: K.m Rajan, P.u Deshpande, K. L. NarasimhanAbstract:Abstract The design of Pressure vessels for critical high-Pressure applications has to consider two failure modes. The first mode of failure can occur when deformation becomes excessive and permanent deformation might occur. The second type of failure occurs at higher magnitudes of Pressure resulting in Bursting of tubes and catastrophic failure. Hence predicting the Bursting Pressure of thrust chambers is an important consideration in their design and gives a more realistic indication of the factor of safety than the value that can be provided based on the yield Pressure value. The burst Pressure gives an indication of the margin of safety available over the maximum expected operating Pressure (MEOP). The assessment of burst Pressure is very important for Pressure vessels which are used for critical applications. In this paper an attempt has been made to study the suitability of the burst Pressure prediction formula available in literature and its modification for thin-walled high strength Pressure vessels manufactured by a flow forming technique.
Zheng Chuanxiang - One of the best experts on this subject based on the ideXlab platform.
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estimate of Bursting Pressure of mild steel Pressure vessel and presentation of Bursting formula
Chinese Journal of Mechanical Engineering (English Edition), 2006Co-Authors: Zheng ChuanxiangAbstract:In order to get more precise Bursting Pressure formula of mild steel, hundreds of Bursting experiments of mild steel Pressure vessels such as Q235(Gr.D) and 20R(1020) are done. Based on statistical data of Bursting Pressure and modification of Faupel formula, a more precise modified formula is given out according to the experimental data. It is proved to be more accurate after examining other Bursting Pressure value presented in many references. This Bursting formula is very accurate in these experiments using Pressure vessels with different diameter and shell thickness. Obviously, this modified Bursting formula can be used in mild steel Pressure vessels with different diameter and thickness of shell.
Volker Seifarth - One of the best experts on this subject based on the ideXlab platform.
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growth modelling promoting mechanical stimulation of smooth muscle cells of porcine tubular organs in a fibrin pvdf scaffold
2018Co-Authors: Volker Seifarth, G M Artmann, Aysegul Temiz Artmann, Minh Tuấn Dương, Manfred StaatAbstract:Reconstructive surgery and tissue replacements like ureters or bladders reconstruction have been recently studied, taking into account growth and remodelling of cells since living cells are capable of growing, adapting, remodelling or degrading and restoring in order to deform and respond to stimuli. Hence, shapes of ureters or bladders and their microstructure change during growth and these changes strongly depend on external stimuli such as training. We present the mechanical stimulation of smooth muscle cells in a tubular fibrin-PVDFA scaffold and the modelling of the growth of tissue by stimuli. To this end, mechanotransduction was performed with a kyphoplasty balloon catheter that was guided through the lumen of the tubular structure. The Bursting Pressure was examined to compare the stability of the incubated tissue constructs. The results showed the significant changes on tissues with training by increasing the burst Pressure as a characteristic mechanical property and the smooth muscle cells were more oriented with uniformly higher density. Besides, the computational growth models also exhibited the accurate tendencies of growth of the cells under different external stimuli. Such models may lead to design standards for the better layered tissue structure in reconstructing of tubular organs characterized as composite materials such as intestines, ureters and arteries.
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mechanical induction of bi directional orientation of primary porcine bladder smooth muscle cells in tubular fibrin poly vinylidene fluoride scaffolds for ureteral and urethral repair using cyclic and focal balloon catheter stimulation
Journal of Biomaterials Applications, 2017Co-Authors: Volker Seifarth, Joachim Grosse, Matthias Gossmann, Heinz P Janke, Patrick Arndt, Sabine Koch, Matthias Epple, G M Artmann, Aysegul Temiz ArtmannAbstract:To restore damaged organ function or to investigate organ mechanisms, it is necessary to prepare replicates that follow the biological role model as faithfully as possible. The interdisciplinary field of tissue engineering has great potential in regenerative medicine and might overcome negative side effects in the replacement of damaged organs. In particular, tubular organ structures of the genitourinary tract, such as the ureter and urethra, are challenging because of their complexity and special milieu that gives rise to incrustation, inflammation and stricture formation. Tubular biohybrids were prepared from primary porcine smooth muscle cells embedded in a fibrin gel with a stabilising poly(vinylidene fluoride) mesh. A mechanotransduction was performed automatically with a balloon kyphoplasty catheter. Diffusion of urea and creatinine, as well as the Bursting Pressure, were measured. Light and electron microscopy were used to visualise cellular distribution and orientation. Histological evaluation rev...
Shunzo Maetani - One of the best experts on this subject based on the ideXlab platform.
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correlation of tensile strength with Bursting Pressure in the evaluation of intestinal anastomosis
Digestive Surgery, 1999Co-Authors: Daisuke Ikeuchi, Hisashi Onodera, Tun Aung, Shugen Kan, Kazuyuki Kawamoto, Masayuki Imamura, Shunzo MaetaniAbstract:Background: Although Bursting Pressure and tensile strength have long been measured to evaluate anastomotic techniques, it has yet to be clarified whether or not they are correlated, what implications they have, and which should be used as a gold standard. Material and Methods: Using an experimental model to estimate Pressure and tension in the same colonic anastomosis, the following variables were measured in 48 rats between days 0 and 14: Bursting Pressure (BP); minimal tensile strength (MITS) necessary to break a part of the anastomosis, and maximal tensile strength (MATS) needed to disrupt the whole anastomosis. Also, circulatory wall tension (CWT) was derived from BP and the anastomotic circumference (AC), and longitudinal wall tension (LWT) from MITS and AC. These variables were compared using correlation and regression analysis. Results: During the lag phase (days ≤4) there was poor correlation between Pressure-related and tension-related variables whereas highly significant correlations were noted in the subsequent fibroplastic phase (day ≥5). It was shown by regression lines that positive MITS and MATS were expected when BP was zero. Conclusion: Contrary to the previous assumption, no correlation was found between BP and tensile strength in the critical postoperative period. Based on our present and previous studies, measurement of MITS is recommended to evaluate the healing of colonic anastomosis.
Ralph V. Clayman - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a vessel sealing system bipolar electrosurgery harmonic scalpel titanium clips endoscopic gastrointestinal anastomosis vascular staples and sutures for arterial and venous ligation in a porcine model
The Journal of Urology, 2003Co-Authors: Jaime Landman, Cassio Andreoni, William Collyer, Ephrem Olweny, Jamil Rehman, Kurt Kerbl, Chandru P Sundaram, Peter A Humphrey, Ralph V. ClaymanAbstract:ABSTRACTPurpose: We assessed the usefulness of the LigaSure (Valleylab, Boulder, Colorado) vessel sealing system for vascular control during laparoscopic surgery and compared it with other available hemostatic modalities.Materials and Methods: A total of 31 domestic pigs were divided into 5 groups. In groups 1 and 2 the vessel sealing system was compared with titanium clips and Endo-GIA (United States Surgical, Stamford, Connecticut) staples. In group 3 the vessel sealing system was compared with standard Klepinger (Karl Storz, Culver City, California) bipolar forceps. In group 4 the harmonic scalpel and Trimax (United States Surgical) bipolar forceps were compared. In group 5 in vivo laparoscopic application of the vessel sealing system was evaluated.Results: The 5 mm. laparoscopic vessel sealing system sealed arteries up to 6 mm. and veins up to 12 mm. in diameter at supraphysiological Bursting Pressure. We evaluated 13 arteries with a diameter of 6 mm. or less at a mean Bursting Pressure of 662 mm. Hg ...
