The Experts below are selected from a list of 15231 Experts worldwide ranked by ideXlab platform
Li Jia - One of the best experts on this subject based on the ideXlab platform.
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prediction of h2 Leak Rate in mica based seals of planar solid oxide fuel cells
Journal of Power Sources, 2008Co-Authors: Shaobai Sang, San Ping Jiang, Li JiaAbstract:Abstract Mica-based materials, either laminated papers or layered single crystals, are popular in solid oxide fuel cell applications as sealing components. Their interface and bulk Leak paths can be considered as slits with various heights, lengths and widths. A hydromechanics model was established based on the geometric assumptions to predict the influence of slit geometry and pressure difference of the seal on H 2 Leak Rate. The dependence of Leak Rate on slit geometry and the pressure difference as well as the effectiveness of compressive loading and compliant interface layer were discussed accordingly. The model's applicability is supported by reported experiments.
N J Persso - One of the best experts on this subject based on the ideXlab platform.
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on the dependence of the Leak Rate of seals on the skewness of the surface height probability distribution
EPL, 2010Co-Authors: N J PerssoAbstract:Seals are extremely useful devices to prevent fluid Leakage. We present experimental result which show that the Leak Rate of seals depend sensitively on the skewness in the height probability distribution. The experimental data are analyzed using the critical-junction theory. We show that using the top power spectrum results in good agreement between theory and experiment.
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Leak Rate of seals comparison of theory with experiment
EPL, 2009Co-Authors: N J PerssoAbstract:Seals are extremely useful devices to prevent fluid Leakage. We present experimental results for the Leak Rate of rubber seals, and compare the results to a novel theory, which is based on percolation theory and a recently developed contact mechanics theory. We find good agreement between theory and experiment.
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theory of the Leak Rate of seals
Journal of Physics: Condensed Matter, 2008Co-Authors: N J Persso, C YangAbstract:Seals are extremely useful devices to prevent fluid Leakage. However, the exact mechanism of roughness induced Leakage is not well understood. We present a theory of the Leak-Rate of seals, which is based on percolation theory and a recently developed contact mechanics theory. We study both static and dynamic seals. We present molecular dynamics results which show that when two elastic solids with randomly rough surfaces are squeezed together, as a function of increasing magnification or decreasing squeezing pressure, a non-contact channel will percolate when the (relative) projected contact area, A/A0, is of the order 0.4, in accordance with percolation theory. We suggest a simple experiment which can be used to test the theory.
Richard Te P G Oek - One of the best experts on this subject based on the ideXlab platform.
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postoperative administration of non steroidal anti inflammatory drugs in colorectal cancer surgery does not increase anastomotic Leak Rate a systematic review and meta analysis
Ejso, 2020Co-Authors: Melissa N N Arro, E J Lie, Johannes H W De Wil, Martij W J Stommel, Harry Van Goo, Richard Te P G OekAbstract:Abstract Background Evidence on the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on anastomotic Leak (AL) Rate after colorectal surgery is conflicting. Effects of NSAIDs might depend on the underlying disease. This meta-analysis aimed to review the effect of NSAIDs on AL Rate in a homogeneous colorectal cancer patient population. Methods A systematic literature search using MEDLINE and EMBASE database was performed for studies with AL as primary outcome comparing NSAID use in the early postoperative phase with no NSAID administration in colorectal cancer patients undergoing surgical resection. Results Nine studies including 10,868 patients met the inclusion criteria. The majority, 7689 patients (70.7%) underwent low anterior resection and 3050 patients (28.1%) underwent colonic resection. The pooled incidence of AL was 8.6% (95%CI 7.0–10.0). Overall AL Rate after colorectal cancer surgery was not increased in patients using NSAIDs for postoperative analgesia compared to non-users (p = 0.34, RR 1.23; 95%CI 0.81–1.86). This effect remained non-significant after stratification for low anterior resections (p = 0.07). Stratification for colonic resections could not be performed because AL results for this subgroup were not reported sepaRately. Neither non-selective NSAID use nor COX-2 selective NSAID use caused an increased AL Rate (p = 0.19, p = 0.26). The results were robust throughout sensitivity analyses. Conclusion Use of NSAIDs in cohorts with patients undergoing surgical resection for colorectal cancer does not increase overall AL Rate. Since results were robust throughout several subgroup and sensitivity analyses, prescription of NSAIDs after colorectal cancer surgery seems safe.
Thomas J Roland - One of the best experts on this subject based on the ideXlab platform.
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prevention and management of cerebrospinal fluid Leak following vestibular schwannoma surgery
Laryngoscope, 2004Co-Authors: Andrew J Fishman, Michelle S Marrinan, John G Golfinos, Noel L Cohen, Thomas J RolandAbstract:OBJECTIVES/HYPOTHESIS: Postoperative cerebrospinal fluid (CSF) Leak is reported in 2% to 30% of cases following vestibular schwannoma surgery. The authors' current surgical techniques for translabyrinthine, retrosigmoid transmeatal, and middle cranial fossa approaches have evolved from analysis of their prior experience in an effort to minimize their complication Rate. The authors evaluated the efficacy of their current surgical technique in decreasing the postoperative CSF Leak Rate. STUDY DESIGN: Retrospective review. METHODS: The vestibular schwannoma database from the New York University Medical Center (New York, NY) neurotological service was reviewed. Data were extracted for type of approach, tumor size, and CSF Leak Rate. Liberal Leak criteria were used. Surgical techniques and management of CSF Leak were reviewed. RESULTS: Data from 215 patients who had surgery from 1995 to 2000 manifested a 6.6% CSF Leak Rate for primary surgeries. This compared favorably with the authors' 17% overall CSF Leak Rate in 555 total primary surgeries performed between 1979 and 1995. Translabyrinthine closure was performed with dural sutures used as a sling across the posterior fossa dura and abdominal fat placed as a series of corks through the sutures. Abdominal fat was used to obliteRate the mastoid cavity in conjunction with aditus and mastoid obliteration. Attention must be paid to soft tissue obliteration of potentially open air cell tracts. Retrosigmoid transmeatal closure was performed with a soft tissue graft in the internal auditory canal drill-out held in position by a "saloon-door" dural flap. Bone wax was used to block perimeatal cells in all cases. Watertight dural closure was achieved with a sutured temporalis fascia graft. Abdominal fat obliteration of the mastoidectomy cavity was performed with an additional firm pressure from the "Palva" periosteal flap. Middle cranial fossa closure was performed with attention to potential air cell tracts of the internal auditory canal drill-out, as well as abdominal fat graft, tissue glue, and bone wax. Fibrin glue was used in all approaches to temporarily secure fat in situ. Management of CSF Leaks starts with nonoperative measures including bed rest, oversewing of incisional wounds, and placement of a lumbar subarachnoid spinal fluid diversion drain. If these conservative measures fail, repeat exploration is necessary and is directed at identifying and corking the cell or cells (usually perimeatal or perilabyrinthine) opening directly into the posterior fossa. CONCLUSION: Evolution in surgical techniques, with particular attention to exposed air cell tracts, abdominal fat graft, and Palva periosteal flap for closure, has had a significant effect in decreasing the author's CSF Leak Rate after vestibular schwannoma surgery. Conservative management was successful in approximately 50% of cases. Repeat exploration, when needed, was directed at blocking the air cell tract (usually perimeatal or perilabyrinthine) responsible for the CSF Leak.
Shaobai Sang - One of the best experts on this subject based on the ideXlab platform.
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prediction of h2 Leak Rate in mica based seals of planar solid oxide fuel cells
Journal of Power Sources, 2008Co-Authors: Shaobai Sang, San Ping Jiang, Li JiaAbstract:Abstract Mica-based materials, either laminated papers or layered single crystals, are popular in solid oxide fuel cell applications as sealing components. Their interface and bulk Leak paths can be considered as slits with various heights, lengths and widths. A hydromechanics model was established based on the geometric assumptions to predict the influence of slit geometry and pressure difference of the seal on H 2 Leak Rate. The dependence of Leak Rate on slit geometry and the pressure difference as well as the effectiveness of compressive loading and compliant interface layer were discussed accordingly. The model's applicability is supported by reported experiments.