The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Daining Fang - One of the best experts on this subject based on the ideXlab platform.
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design and analysis of integrated thermal protection system based on lightweight c sic pyramidal lattice core sandwich panel
Materials & Design, 2016Co-Authors: Kai Wei, Xiangmeng Cheng, Daining Fang, Weibin WenAbstract:Abstract Thermal protection system (TPS) plays the key role to successful development of hypersonic vehicles. Here, a novel structurally and thermally integrated thermal protection system (ITPS) based on the lightweight C/SiC pyramidal core lattice sandwich panel is proposed. This ITPS integrates advantages of low areal density and high temperature resistance up to 1600 °C. Heat transfer characteristics and compressive responses of the C/SiC sandwich panel are established in advance. The results demonstrate that filling alumina fibers in the pore significantly reduce the effective thermal conductivity from 2.45–4.83 W/m °C to no more than 0.7 W/m °C. The critical relative density is determinated for the failure models under aerodynamic Pressure Load. Meanwhile, an analysis procedure of the ITPS is exclusively established under typical aerodynamic heat flux and Pressure Load. With fulfillment of both temperature and mechanical constraints, minimum areal density is obtained. Compared with current metal corrugated core ITPS, the ITPS proposed here significantly raises the temperature limitation up to 1600 °C and reduces the areal density up to 35%, and is very promising for potential application in hypersonic vehicles.
Kai Wei - One of the best experts on this subject based on the ideXlab platform.
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design and analysis of integrated thermal protection system based on lightweight c sic pyramidal lattice core sandwich panel
Materials & Design, 2016Co-Authors: Kai Wei, Xiangmeng Cheng, Daining Fang, Weibin WenAbstract:Abstract Thermal protection system (TPS) plays the key role to successful development of hypersonic vehicles. Here, a novel structurally and thermally integrated thermal protection system (ITPS) based on the lightweight C/SiC pyramidal core lattice sandwich panel is proposed. This ITPS integrates advantages of low areal density and high temperature resistance up to 1600 °C. Heat transfer characteristics and compressive responses of the C/SiC sandwich panel are established in advance. The results demonstrate that filling alumina fibers in the pore significantly reduce the effective thermal conductivity from 2.45–4.83 W/m °C to no more than 0.7 W/m °C. The critical relative density is determinated for the failure models under aerodynamic Pressure Load. Meanwhile, an analysis procedure of the ITPS is exclusively established under typical aerodynamic heat flux and Pressure Load. With fulfillment of both temperature and mechanical constraints, minimum areal density is obtained. Compared with current metal corrugated core ITPS, the ITPS proposed here significantly raises the temperature limitation up to 1600 °C and reduces the areal density up to 35%, and is very promising for potential application in hypersonic vehicles.
Serge Brimioulle - One of the best experts on this subject based on the ideXlab platform.
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effects of levosimendan versus dobutamine on Pressure Load induced right ventricular failure
Critical Care Medicine, 2006Co-Authors: Francois Kerbaul, Benoit Rondelet, Jeanpaul Demester, Pierre Fesler, Sandrine Huez, Robert Naeije, Serge BrimioulleAbstract:OBJECTIVE: A transient increase in pulmonary arterial (PA) Pressure can persistently depress right ventricular (RV) contractility. We investigated the effects of dobutamine and levosimendan on RV-PA coupling in this model of RV failure. DESIGN: Prospective, controlled, randomized animal study. SETTING: University research laboratory. SUBJECTS: Fifteen anesthetized dogs. INTERVENTIONS: Transient (90-min) PA constriction to induce persistent RV failure. Random assignment to dobutamine 5 and 10 μg/kg/min or levosimendan 12 μg/kg for 10 mins followed by 0.1 and 0.2 μg/kg/min. MEASUREMENTS AND MAIN RESULTS: We measured PA distal resistance and proximal elastance by Pressure-flow relationships and vascular impedance. We measured RV contractility by the end-systolic Pressure-volume relationship (Ees), PA effective elastance by the end-diastolic to end-systolic relationship (Ea), and RV-PA coupling efficiency by the Ees/Ea ratio. PA constriction persistently increased PA resistance and elastance, increased Ea from 0.95 ± 0.07 to 3.01 ± 0.28 mm Hg/mL, decreased Ees from 1.17 ± 0.09 to 0.58 ± 0.07 mm Hg/mL, and decreased Ees/Ea from 1.26 ± 0.09 to 0.22 ± 0.03 (p < .05). Dobutamine did not affect pulmonary hemodynamics, markedly increased RV contractility, and improved RV-PA coupling. Levosimendan decreased PA resistance and elastance, increased RV contractility, and restored RV-PA coupling. Compared with dobutamine, levosimendan decreased RV afterLoad and therefore better restored RV-PA coupling at similar inotropic state. CONCLUSIONS: A transient increase in PA Pressure persistently worsens PA hemodynamics, RV contractility, RV-PA coupling, and cardiac output. Levosimendan restores RV-PA coupling better than dobutamine because of similar inotropic effects and additional pulmonary vasodilatory effects. © 2006 Lippincott Williams & Wilkins, Inc.
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effects of norepinephrine and dobutamine on Pressure Load induced right ventricular failure
Critical Care Medicine, 2004Co-Authors: Francois Kerbaul, Benoit Rondelet, Pierre Fesler, Robert Naeije, Sophie Motte, Ives Hubloue, Patricia Ewalenko, Serge BrimioulleAbstract:ObjectiveA transient increase in pulmonary arterial (PA) Pressure can persistently depress right ventricular (RV) contractility. We investigated the effects norepinephrine and dobutamine on RV-PA coupling in this model of RV failure.DesignProspective, controlled, randomized animal study.SettingUnive
Frank P T Baaijens - One of the best experts on this subject based on the ideXlab platform.
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modeling the mechanics of tissue engineered human heart valve leaflets
Journal of Biomechanics, 2007Co-Authors: Niels J B Driessen, Anita Mol, Carlijn V C Bouten, Frank P T BaaijensAbstract:Mathematical models can provide valuable information to assess and evaluate the mechanical behavior of tissue-engineered constructs. In this study, a structurally based model is applied to describe and analyze the mechanics of tissue-engineered human heart valve leaflets. The results from two orthogonal uniaxial tensile tests are used to determine the model parameters of the constructs after two, three and four weeks of culturing. Subsequently, finite element analyses are performed to simulate the mechanical response of the engineered leaflets to a Pressure Load. The stresses in the leaflets induced by the Pressure Load increase monotonically with culture time due to a decrease in the construct's thickness. The strains, on the other hand, eventually decrease as a result of an increase in the elastic modulus. Compared to native porcine leaflets, the mechanical response of the engineered tissues after four weeks of culturing is more linear, stiffer and less anisotropic.
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modeling the mechanics of tissue engineered human heart valve leaflets
Mate Poster Award 2005 : 10th Annual Poster Contest, 2005Co-Authors: Njb Niels Driessen, Carlijn V C Bouten, Anita Anita Driessenmol, Frank P T BaaijensAbstract:Mathematical models can provide valuable information to assess and evaluate the mechanical behavior of tissue-engineered constructs. In this study, a structurally based model is applied to describe and analyze the mechanics of tissue-engineered human heart valve leaflets. The results from two orthogonal uniaxial tensile tests are used to determine the model parameters of the constructs after two, three and four weeks of culturing. Subsequently, finite element analyses are performed to simulate the mechanical response of the engineered leaflets to a Pressure Load. The stresses in the leaflets induced by the Pressure Load increase monotonically with culture time due to a decrease in the construct’s thickness. The strains, on the other hand, eventually decrease as a result of an increase in the elastic modulus. Compared to native porcine leaflets, the mechanical response of the engineered tissues after four weeks of culturing is more linear, stiffer and less anisotropic. r 2006 Elsevier Ltd. All rights reserved.
Francois Kerbaul - One of the best experts on this subject based on the ideXlab platform.
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effects of levosimendan versus dobutamine on Pressure Load induced right ventricular failure
Critical Care Medicine, 2006Co-Authors: Francois Kerbaul, Benoit Rondelet, Jeanpaul Demester, Pierre Fesler, Sandrine Huez, Robert Naeije, Serge BrimioulleAbstract:OBJECTIVE: A transient increase in pulmonary arterial (PA) Pressure can persistently depress right ventricular (RV) contractility. We investigated the effects of dobutamine and levosimendan on RV-PA coupling in this model of RV failure. DESIGN: Prospective, controlled, randomized animal study. SETTING: University research laboratory. SUBJECTS: Fifteen anesthetized dogs. INTERVENTIONS: Transient (90-min) PA constriction to induce persistent RV failure. Random assignment to dobutamine 5 and 10 μg/kg/min or levosimendan 12 μg/kg for 10 mins followed by 0.1 and 0.2 μg/kg/min. MEASUREMENTS AND MAIN RESULTS: We measured PA distal resistance and proximal elastance by Pressure-flow relationships and vascular impedance. We measured RV contractility by the end-systolic Pressure-volume relationship (Ees), PA effective elastance by the end-diastolic to end-systolic relationship (Ea), and RV-PA coupling efficiency by the Ees/Ea ratio. PA constriction persistently increased PA resistance and elastance, increased Ea from 0.95 ± 0.07 to 3.01 ± 0.28 mm Hg/mL, decreased Ees from 1.17 ± 0.09 to 0.58 ± 0.07 mm Hg/mL, and decreased Ees/Ea from 1.26 ± 0.09 to 0.22 ± 0.03 (p < .05). Dobutamine did not affect pulmonary hemodynamics, markedly increased RV contractility, and improved RV-PA coupling. Levosimendan decreased PA resistance and elastance, increased RV contractility, and restored RV-PA coupling. Compared with dobutamine, levosimendan decreased RV afterLoad and therefore better restored RV-PA coupling at similar inotropic state. CONCLUSIONS: A transient increase in PA Pressure persistently worsens PA hemodynamics, RV contractility, RV-PA coupling, and cardiac output. Levosimendan restores RV-PA coupling better than dobutamine because of similar inotropic effects and additional pulmonary vasodilatory effects. © 2006 Lippincott Williams & Wilkins, Inc.
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effects of norepinephrine and dobutamine on Pressure Load induced right ventricular failure
Critical Care Medicine, 2004Co-Authors: Francois Kerbaul, Benoit Rondelet, Pierre Fesler, Robert Naeije, Sophie Motte, Ives Hubloue, Patricia Ewalenko, Serge BrimioulleAbstract:ObjectiveA transient increase in pulmonary arterial (PA) Pressure can persistently depress right ventricular (RV) contractility. We investigated the effects norepinephrine and dobutamine on RV-PA coupling in this model of RV failure.DesignProspective, controlled, randomized animal study.SettingUnive
