The Experts below are selected from a list of 144765 Experts worldwide ranked by ideXlab platform
Joaquim Peiró - One of the best experts on this subject based on the ideXlab platform.
-
Pulse wave propagation in a model human arterial Network: Assessment of 1-D visco-elastic simulations against in vitro measurements.
Journal of biomechanics, 2011Co-Authors: Jordi Alastruey, Ashraf W Khir, Koen S Matthys, Patrick Segers, Spencer J Sherwin, Pascal R Verdonck, Kim H Parker, Joaquim PeiróAbstract:The accuracy of the nonlinear one-dimensional (1-D) equations of pressure and flow wave propagation in Voigt-type visco-elastic arteries was tested against measurements in a well-defined experimental 1:1 replica of the 37 largest conduit arteries in the human systemic circulation. The parameters required by the numerical algorithm were directly measured in the in vitro setup and no data fitting was involved. The inclusion of wall visco-elasticity in the numerical model reduced the underdamped high-frequency oscillations obtained using a purely elastic tube law, especially in peripheral vessels, which was previously reported in this paper [Matthys et al., 2007. Pulse wave propagation in a model human arterial Network: Assessment of 1-D numerical simulations against in vitro measurements. J. Biomech. 40, 3476-3486]. In comparison to the purely elastic model, visco-elasticity significantly reduced the average relative root-mean-square errors between numerical and experimental waveforms over the 70 locations measured in the in vitro model: from 3.0% to 2.5% (p
-
pulse wave propagation in a model human arterial Network Assessment of 1 d visco elastic simulations against in vitro measurements
Journal of Biomechanics, 2007Co-Authors: Jordi Alastruey, Ashraf W Khir, Patrick Segers, Spencer J Sherwin, Kim H Parker, Koen Matthys, Pascal Verdonck, Joaquim PeiróAbstract:A numerical model based on the nonlinear, one-dimensional (1-D) equations of pressure and flow wave propagation in conduit arteries is tested against a well-defined experimental 1:1 replica of the human arterial tree. The tree consists of 37 silicone branches representing the largest central systemic arteries in the human, including the aorta, carotid arteries and arteries that perfuse the upper and lower limbs and the main abdominal organs. The set-up is mounted horizontally and connected to a pulsatile pump delivering a periodic output similar to the aortic flow. Terminal branches end in simple resistance models, consisting of stiff capillary tubes leading to an overflow reservoir that reflects a constant venous pressure. The parameters required by the numerical algorithm are directly measured in the in vitro set-up and no data fitting is involved. Comparison of experimental and numerical pressure and flow waveforms shows the ability of the 1-D time-domain formulation to capture the main features of pulse wave propagation measured throughout the system test. As a consequence of the simple resistive boundary conditions used to reduce the uncertainty of the parameters involved in the simulation, the experimental set-up generates waveforms at terminal branches with additional non-physiological oscillations. The frequencies of these oscillations are well captured by the 1-D model, even though amplitudes are overestimated. Adding energy losses in bifurcations and including fluid inertia and compliance to the purely resistive terminal models does not reduce the underdamped effect, suggesting that wall visco-elasticity might play an important role in the experimental results. Nevertheless, average relative root-mean-square errors between simulations and experimental waveforms are smaller than 4% for pressure and 19% for the flow at all 70 locations studied.
Jordi Alastruey - One of the best experts on this subject based on the ideXlab platform.
-
Pulse wave propagation in a model human arterial Network: Assessment of 1-D visco-elastic simulations against in vitro measurements.
Journal of biomechanics, 2011Co-Authors: Jordi Alastruey, Ashraf W Khir, Koen S Matthys, Patrick Segers, Spencer J Sherwin, Pascal R Verdonck, Kim H Parker, Joaquim PeiróAbstract:The accuracy of the nonlinear one-dimensional (1-D) equations of pressure and flow wave propagation in Voigt-type visco-elastic arteries was tested against measurements in a well-defined experimental 1:1 replica of the 37 largest conduit arteries in the human systemic circulation. The parameters required by the numerical algorithm were directly measured in the in vitro setup and no data fitting was involved. The inclusion of wall visco-elasticity in the numerical model reduced the underdamped high-frequency oscillations obtained using a purely elastic tube law, especially in peripheral vessels, which was previously reported in this paper [Matthys et al., 2007. Pulse wave propagation in a model human arterial Network: Assessment of 1-D numerical simulations against in vitro measurements. J. Biomech. 40, 3476-3486]. In comparison to the purely elastic model, visco-elasticity significantly reduced the average relative root-mean-square errors between numerical and experimental waveforms over the 70 locations measured in the in vitro model: from 3.0% to 2.5% (p
-
pulse wave propagation in a model human arterial Network Assessment of 1 d visco elastic simulations against in vitro measurements
Journal of Biomechanics, 2007Co-Authors: Jordi Alastruey, Ashraf W Khir, Patrick Segers, Spencer J Sherwin, Kim H Parker, Koen Matthys, Pascal Verdonck, Joaquim PeiróAbstract:A numerical model based on the nonlinear, one-dimensional (1-D) equations of pressure and flow wave propagation in conduit arteries is tested against a well-defined experimental 1:1 replica of the human arterial tree. The tree consists of 37 silicone branches representing the largest central systemic arteries in the human, including the aorta, carotid arteries and arteries that perfuse the upper and lower limbs and the main abdominal organs. The set-up is mounted horizontally and connected to a pulsatile pump delivering a periodic output similar to the aortic flow. Terminal branches end in simple resistance models, consisting of stiff capillary tubes leading to an overflow reservoir that reflects a constant venous pressure. The parameters required by the numerical algorithm are directly measured in the in vitro set-up and no data fitting is involved. Comparison of experimental and numerical pressure and flow waveforms shows the ability of the 1-D time-domain formulation to capture the main features of pulse wave propagation measured throughout the system test. As a consequence of the simple resistive boundary conditions used to reduce the uncertainty of the parameters involved in the simulation, the experimental set-up generates waveforms at terminal branches with additional non-physiological oscillations. The frequencies of these oscillations are well captured by the 1-D model, even though amplitudes are overestimated. Adding energy losses in bifurcations and including fluid inertia and compliance to the purely resistive terminal models does not reduce the underdamped effect, suggesting that wall visco-elasticity might play an important role in the experimental results. Nevertheless, average relative root-mean-square errors between simulations and experimental waveforms are smaller than 4% for pressure and 19% for the flow at all 70 locations studied.
Pawan Kumar Labhasetwar - One of the best experts on this subject based on the ideXlab platform.
-
Distribution Network Assessment using EPANET for Intermittent and Continuous Water Supply
Water Resources Management, 2014Co-Authors: Sanjeeb Mohapatra, Aabha Sargaonkar, Pawan Kumar LabhasetwarAbstract:Drawbacks of intermittent water supply system and inability to shift to continuous supply mode is the main challenge in developing countries. The suitability of the infrastructure laid over past two to three decades to meet the 24/7 demand of todays population is the issue for many water mangers. The present study addresses this issue using EPANET software for a pilot study area in Nagpur city, India. GIS maps, field survey data, remote sensing data and in-situ measurements of pressure and water quality are used in model simulation study. Total 96 artificial reservoirs are inserted into the Network which replicate the end-user practices of excess water withdrawal. Reservoirs are assumed connected to damand nodes with equivalent diameter pipes for intermittent supply simulation. For continuous supply, demand multipliers are derived using Monte Carlo simulation. Bulk decay coefficient 0.17 day^−1 for residual chlorine is used in water quality simulation. Simulation scenario of intermittency indicates existing Network is not suitable to maintain desired headloss, and pressure in most of the pipes is very low (
-
Distribution Network Assessment using EPANET for Intermittent and Continuous Water Supply
Water Resources Management, 2014Co-Authors: Sanjeeb Mohapatra, Aabha Sargaonkar, Pawan Kumar LabhasetwarAbstract:Drawbacks of intermittent water supply system and inability to shift to continuous supply mode is the main challenge in developing countries. The suitability of the infrastructure laid over past two to three decades to meet the 24/7 demand of todays population is the issue for many water mangers. The present study addresses this issue using EPANET software for a pilot study area in Nagpur city, India. GIS maps, field survey data, remote sensing data and in-situ measurements of pressure and water quality are used in model simulation study. Total 96 artificial reservoirs are inserted into the Network which replicate the end-user practices of excess water withdrawal. Reservoirs are assumed connected to damand nodes with equivalent diameter pipes for intermittent supply simulation. For continuous supply, demand multipliers are derived using Monte Carlo simulation. Bulk decay coefficient 0.17 day −1 for residual chlorine is used in water quality simulation. Simulation scenario of intermittency indicates existing Network is not suitable to maintain desired headloss, and pressure in most of the pipes is very low (>1 m). Water age and water quality problems reveal that rehabilitation of distribution mains and critical pipes in the central part is primarily important before implementing 24/7 water supply scheme in the study area. Copyright Springer Science+Business Media Dordrecht 2014
Spencer J Sherwin - One of the best experts on this subject based on the ideXlab platform.
-
Pulse wave propagation in a model human arterial Network: Assessment of 1-D visco-elastic simulations against in vitro measurements.
Journal of biomechanics, 2011Co-Authors: Jordi Alastruey, Ashraf W Khir, Koen S Matthys, Patrick Segers, Spencer J Sherwin, Pascal R Verdonck, Kim H Parker, Joaquim PeiróAbstract:The accuracy of the nonlinear one-dimensional (1-D) equations of pressure and flow wave propagation in Voigt-type visco-elastic arteries was tested against measurements in a well-defined experimental 1:1 replica of the 37 largest conduit arteries in the human systemic circulation. The parameters required by the numerical algorithm were directly measured in the in vitro setup and no data fitting was involved. The inclusion of wall visco-elasticity in the numerical model reduced the underdamped high-frequency oscillations obtained using a purely elastic tube law, especially in peripheral vessels, which was previously reported in this paper [Matthys et al., 2007. Pulse wave propagation in a model human arterial Network: Assessment of 1-D numerical simulations against in vitro measurements. J. Biomech. 40, 3476-3486]. In comparison to the purely elastic model, visco-elasticity significantly reduced the average relative root-mean-square errors between numerical and experimental waveforms over the 70 locations measured in the in vitro model: from 3.0% to 2.5% (p
-
pulse wave propagation in a model human arterial Network Assessment of 1 d visco elastic simulations against in vitro measurements
Journal of Biomechanics, 2007Co-Authors: Jordi Alastruey, Ashraf W Khir, Patrick Segers, Spencer J Sherwin, Kim H Parker, Koen Matthys, Pascal Verdonck, Joaquim PeiróAbstract:A numerical model based on the nonlinear, one-dimensional (1-D) equations of pressure and flow wave propagation in conduit arteries is tested against a well-defined experimental 1:1 replica of the human arterial tree. The tree consists of 37 silicone branches representing the largest central systemic arteries in the human, including the aorta, carotid arteries and arteries that perfuse the upper and lower limbs and the main abdominal organs. The set-up is mounted horizontally and connected to a pulsatile pump delivering a periodic output similar to the aortic flow. Terminal branches end in simple resistance models, consisting of stiff capillary tubes leading to an overflow reservoir that reflects a constant venous pressure. The parameters required by the numerical algorithm are directly measured in the in vitro set-up and no data fitting is involved. Comparison of experimental and numerical pressure and flow waveforms shows the ability of the 1-D time-domain formulation to capture the main features of pulse wave propagation measured throughout the system test. As a consequence of the simple resistive boundary conditions used to reduce the uncertainty of the parameters involved in the simulation, the experimental set-up generates waveforms at terminal branches with additional non-physiological oscillations. The frequencies of these oscillations are well captured by the 1-D model, even though amplitudes are overestimated. Adding energy losses in bifurcations and including fluid inertia and compliance to the purely resistive terminal models does not reduce the underdamped effect, suggesting that wall visco-elasticity might play an important role in the experimental results. Nevertheless, average relative root-mean-square errors between simulations and experimental waveforms are smaller than 4% for pressure and 19% for the flow at all 70 locations studied.
Kim H Parker - One of the best experts on this subject based on the ideXlab platform.
-
Pulse wave propagation in a model human arterial Network: Assessment of 1-D visco-elastic simulations against in vitro measurements.
Journal of biomechanics, 2011Co-Authors: Jordi Alastruey, Ashraf W Khir, Koen S Matthys, Patrick Segers, Spencer J Sherwin, Pascal R Verdonck, Kim H Parker, Joaquim PeiróAbstract:The accuracy of the nonlinear one-dimensional (1-D) equations of pressure and flow wave propagation in Voigt-type visco-elastic arteries was tested against measurements in a well-defined experimental 1:1 replica of the 37 largest conduit arteries in the human systemic circulation. The parameters required by the numerical algorithm were directly measured in the in vitro setup and no data fitting was involved. The inclusion of wall visco-elasticity in the numerical model reduced the underdamped high-frequency oscillations obtained using a purely elastic tube law, especially in peripheral vessels, which was previously reported in this paper [Matthys et al., 2007. Pulse wave propagation in a model human arterial Network: Assessment of 1-D numerical simulations against in vitro measurements. J. Biomech. 40, 3476-3486]. In comparison to the purely elastic model, visco-elasticity significantly reduced the average relative root-mean-square errors between numerical and experimental waveforms over the 70 locations measured in the in vitro model: from 3.0% to 2.5% (p
-
pulse wave propagation in a model human arterial Network Assessment of 1 d visco elastic simulations against in vitro measurements
Journal of Biomechanics, 2007Co-Authors: Jordi Alastruey, Ashraf W Khir, Patrick Segers, Spencer J Sherwin, Kim H Parker, Koen Matthys, Pascal Verdonck, Joaquim PeiróAbstract:A numerical model based on the nonlinear, one-dimensional (1-D) equations of pressure and flow wave propagation in conduit arteries is tested against a well-defined experimental 1:1 replica of the human arterial tree. The tree consists of 37 silicone branches representing the largest central systemic arteries in the human, including the aorta, carotid arteries and arteries that perfuse the upper and lower limbs and the main abdominal organs. The set-up is mounted horizontally and connected to a pulsatile pump delivering a periodic output similar to the aortic flow. Terminal branches end in simple resistance models, consisting of stiff capillary tubes leading to an overflow reservoir that reflects a constant venous pressure. The parameters required by the numerical algorithm are directly measured in the in vitro set-up and no data fitting is involved. Comparison of experimental and numerical pressure and flow waveforms shows the ability of the 1-D time-domain formulation to capture the main features of pulse wave propagation measured throughout the system test. As a consequence of the simple resistive boundary conditions used to reduce the uncertainty of the parameters involved in the simulation, the experimental set-up generates waveforms at terminal branches with additional non-physiological oscillations. The frequencies of these oscillations are well captured by the 1-D model, even though amplitudes are overestimated. Adding energy losses in bifurcations and including fluid inertia and compliance to the purely resistive terminal models does not reduce the underdamped effect, suggesting that wall visco-elasticity might play an important role in the experimental results. Nevertheless, average relative root-mean-square errors between simulations and experimental waveforms are smaller than 4% for pressure and 19% for the flow at all 70 locations studied.