The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Zhiwei Lu - One of the best experts on this subject based on the ideXlab platform.
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measurement of the threshold of nonfocusing pumped stimulated brillouin scattering based on temporal characteristic of the Reflected Pulse
Applied Physics Express, 2014Co-Authors: Yulei Wang, Zhiwei LuAbstract:We present a novel method for measuring the threshold of stimulated Brillouin scattering with large-aperture super-Gaussian-shaped laser Pulses transmitting in a nonlinear medium. From the differences between the waveforms of Reflected light below and above the SBS threshold and the "energy in the bucket" method, threshold pump intensity can be determined clearly. Experiment is carried out with a high-power Nd:glass laser system of 527 nm wavelength, used as the light source that delivers 3 ns super-Gaussian-shaped Pulses, and the nonlinear medium FC-40. The experimental results agree well with the numerically calculated results, and the SBS threshold in this case is 780 MW/cm2.
Yulei Wang - One of the best experts on this subject based on the ideXlab platform.
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measurement of the threshold of nonfocusing pumped stimulated brillouin scattering based on temporal characteristic of the Reflected Pulse
Applied Physics Express, 2014Co-Authors: Yulei Wang, Zhiwei LuAbstract:We present a novel method for measuring the threshold of stimulated Brillouin scattering with large-aperture super-Gaussian-shaped laser Pulses transmitting in a nonlinear medium. From the differences between the waveforms of Reflected light below and above the SBS threshold and the "energy in the bucket" method, threshold pump intensity can be determined clearly. Experiment is carried out with a high-power Nd:glass laser system of 527 nm wavelength, used as the light source that delivers 3 ns super-Gaussian-shaped Pulses, and the nonlinear medium FC-40. The experimental results agree well with the numerically calculated results, and the SBS threshold in this case is 780 MW/cm2.
Harry Aj Struijker-boudier - One of the best experts on this subject based on the ideXlab platform.
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Central hemodynamics in relation to low-level environmental lead exposure
'Informa UK Limited', 2019Co-Authors: Yu Cai-guo, Wei Fang-fei, Yang Wen-yi, Zhang Zhen-yu, Mujaj Blerim, Thijs Lutgarde, Feng Ying-mei, Boggia Jose, Roels, Harry A, Harry Aj Struijker-boudierAbstract:Background: Aortic Pulse wave velocity (aPWV) predicts cardiovascular complications, but the association of central arterial properties with blood lead level (BL) is poorly documented. We therefore assessed their association with BL in 150 young men prior to occupational lead exposure, using baseline data of the Study for Promotion of Health in Recycling Lead (NCT02243904). Methods: Study nurses administered validated questionnaires and performed clinical measurements. Venous blood samples were obtained after 8-12 h of fasting. The radial, carotid and femoral Pulse waves were tonometrically recorded. We accounted for ethnicity, age, anthropometric characteristics, mean arterial pressure, heart rate, smoking and drinking, and total and high-density lipoprotein serum cholesterol, as appropriate. Results: Mean values were 4.14 μg/dL for BL, 27 years for age, 108/79/28 mm Hg for central systolic/diastolic/Pulse pressure, 100/10% for the augmentation ratio/index, 1.63 for pressure amplification, 5.94 m/s for aPWV, 27/11 mm Hg for the forward/backward Pulse pressure height, and 43% for the reflection index. Per 10-fold BL increase, central diastolic pressure and the augmentation ratio were respectively 5.37 mm Hg (95% confidence interval [CI], 1.00-9.75) and 1.57 (CI, 0.20-2.94) greater, whereas central Pulse pressure and the forward Pulse pressure height were 3.74 mm Hg (CI, 0.60-6.88) and 3.37 mm Hg (CI, 0.22-6.53) smaller (p ≤ .036 for all). The other hemodynamic measurements were unrelated to BL. The Reflected Pulse peak time was inversely correlated with diastolic pressure (r = -0.20; p ≤ .017). Conclusion: At the exposure levels observed in our current study, aPWV, the gold standard to assess arterial stiffness, was not associated with BL. Increased peripheral arterial resistance, as Reflected by higher diastolic pressure, might bring reflection points closer to the heart, thereby moving the backward wave into systole and increasing the augmentation ratio in relation to BL.status: publishe
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Central hemodynamics in relation to blood lead in young men prior to chronic occupational exposure
'Informa UK Limited', 2019Co-Authors: Yu Cai-guo, Wei Fang-fei, Yang Wen-yi, Zhang Zhen-yu, Mujaj Blerim, Thijs Lutgarde, Feng Ying-mei, Boggia Jose, Nawrot, Tim S, Harry Aj Struijker-boudierAbstract:Background: Aortic Pulse wave velocity (aPWV) predicts cardiovascular complications, but the association of central arterial properties with blood lead level (BL) is poorly documented. We therefore assessed their association with BL in 150 young men prior to occupational lead exposure, using baseline data of the Study for Promotion of Health in Recycling Lead (NCT02243904). Methods: Study nurses administered validated questionnaires and performed clinical measurements. Venous blood samples were obtained after 8-12 h of fasting. The radial, carotid and femoral Pulse waves were tonometrically recorded. We accounted for ethnicity, age, anthropometric characteristics, mean arterial pressure, heart rate, smoking and drinking, and total and high-density lipoprotein serum cholesterol, as appropriate. Results: Mean values were 4.14 μg/dL for BL, 27 years for age, 108/79/28 mm Hg for central systolic/diastolic/Pulse pressure, 100/10% for the augmentation ratio/index, 1.63 for pressure amplification, 5.94 m/s for aPWV, 27/11 mm Hg for the forward/backward Pulse pressure height, and 43% for the reflection index. Per 10-fold BL increase, central diastolic pressure and the augmentation ratio were respectively 5.37 mm Hg (95% confidence interval [CI], 1.00-9.75) and 1.57 (CI, 0.20-2.94) greater, whereas central Pulse pressure and the forward Pulse pressure height were 3.74 mm Hg (CI, 0.60-6.88) and 3.37 mm Hg (CI, 0.22-6.53) smaller (p ≤ .036 for all). The other hemodynamic measurements were unrelated to BL. The Reflected Pulse peak time was inversely correlated with diastolic pressure (r = -0.20; p ≤ .017). Conclusion: At the exposure levels observed in our current study, aPWV, the gold standard to assess arterial stiffness, was not associated with BL. Increased peripheral arterial resistance, as Reflected by higher diastolic pressure, might bring reflection points closer to the heart, thereby moving the backward wave into systole and increasing the augmentation ratio in relation to BL.status: publishe
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Central hemodynamics in relation to blood lead in young men prior to chronic occupational exposure
2019Co-Authors: Fang-fei Wei, Wen-yi Yang, Zhen-yu Zhang, Blerim Mujaj, Lutgarde Thijs, Ying-mei Feng, José Boggia, Tim S. Nawrot, Harry Aj Struijker-boudierAbstract:Background: Aortic Pulse wave velocity (aPWV) predicts cardiovascular complications, but the association of central arterial properties with blood lead level (BL) is poorly documented. We therefore assessed their association with BL in 150 young men prior to occupational lead exposure, using baseline data of the Study for Promotion of Health in Recycling Lead (NCT02243904). Methods: Study nurses administered validated questionnaires and performed clinical measurements. Venous blood samples were obtained after 8–12 h of fasting. The radial, carotid and femoral Pulse waves were tonometrically recorded. We accounted for ethnicity, age, anthropometric characteristics, mean arterial pressure, heart rate, smoking and drinking, and total and high-density lipoprotein serum cholesterol, as appropriate. Results: Mean values were 4.14 μg/dL for BL, 27 years for age, 108/79/28 mm Hg for central systolic/diastolic/Pulse pressure, 100/10% for the augmentation ratio/index, 1.63 for pressure amplification, 5.94 m/s for aPWV, 27/11 mm Hg for the forward/backward Pulse pressure height, and 43% for the reflection index. Per 10-fold BL increase, central diastolic pressure and the augmentation ratio were respectively 5.37 mm Hg (95% confidence interval [CI], 1.00–9.75) and 1.57 (CI, 0.20–2.94) greater, whereas central Pulse pressure and the forward Pulse pressure height were 3.74 mm Hg (CI, 0.60–6.88) and 3.37 mm Hg (CI, 0.22–6.53) smaller (p ≤ .036 for all). The other hemodynamic measurements were unrelated to BL. The Reflected Pulse peak time was inversely correlated with diastolic pressure (r = −0.20; p ≤ .017). Conclusion: At the exposure levels observed in our current study, aPWV, the gold standard to assess arterial stiffness, was not associated with BL. Increased peripheral arterial resistance, as Reflected by higher diastolic pressure, might bring reflection points closer to the heart, thereby moving the backward wave into systole and increasing the augmentation ratio in relation to BL.
Jin-kyu Byun - One of the best experts on this subject based on the ideXlab platform.
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Sensitivity Analysis of Water Tree and Input Pulse Parameters for Time-Domain Refl ectometry of Power Cables Using Taguchi Method
Journal of Electrical Engineering & Technology, 2020Co-Authors: Han-ju Kim, Ji-san Park, Jaegyeong Mun, Dong-hun Kim, Seung Hwangbo, Jin-kyu ByunAbstract:In this paper, quantitative sensitivity analyses of various parameters of water tree and input Pulse are performed using Taguchi-based design of experiment method in order to verify the feasibility of time-domain reflectometry (TDR) method for the water tree detection in the power cable. Signal to noise ratio (SNR) and percent contribution (PC) of water tree and diagnostic Pulse parameters are calculated, and the parameters are identified that have high influence on the Reflected Pulse. The simulation software (COMSOL Multiphysics) used for the analysis is verified by comparison with the experimental results of the cable with an artificial defect. Based on the sensitivity analysis, optimal diagnostic Pulse parameters are proposed for the efficient detection of the water trees.
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Sensitivity Analysis of Water Tree and Input Pulse Parameters for Time-Domain Reflectometry of Power Cables Using Taguchi Method
Journal of Electrical Engineering & Technology, 2020Co-Authors: Han-ju Kim, Ji-san Park, Jaegyeong Mun, Dong-hun Kim, Seung Hwangbo, Jin-kyu ByunAbstract:In this paper, quantitative sensitivity analyses of various parameters of water tree and input Pulse are performed using Taguchi-based design of experiment method in order to verify the feasibility of time-domain reflectometry (TDR) method for the water tree detection in the power cable. Signal to noise ratio (SNR) and percent contribution (PC) of water tree and diagnostic Pulse parameters are calculated, and the parameters are identified that have high influence on the Reflected Pulse. The simulation software (COMSOL Multiphysics) used for the analysis is verified by comparison with the experimental results of the cable with an artificial defect. Based on the sensitivity analysis, optimal diagnostic Pulse parameters are proposed for the efficient detection of the water trees.
Xuehua Zhu - One of the best experts on this subject based on the ideXlab platform.
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measurement of the threshold of nonfocusing pumped stimulated brillouin scattering based on the spatial characteristic of the Reflected Pulse
Applied Optics, 2019Co-Authors: Xuehua ZhuAbstract:We present a method for measuring the threshold of stimulated Brillouin scattering (SBS) when a large-aperture laser Pulse with ultra-Gaussian shape is used as the pump source. By using an optical aperture to filter out part of the backward scattered light, the measured energy efficiency will be conserved below the SBS threshold and nonconserved above the SBS threshold. Based on the differences between the two conditions we can judge whether the pump intensity is above the SBS threshold or not by analysis of the energy efficiency of the system. The experiment is carried out with an Nd:YAG laser, delivering an ultra-Gaussian-shaped Pulse with the Pulse width of 3 ns, beam diameter of about 20 mm, and wavelength of 527 nm. Heavy fluorocarbon liquid FC-770 is adopted as the nonlinear medium. The measured SBS threshold under this condition is 634 MW/cm2 and it has a good correspondence with the theoretically calculated results.
