Results 1 to 10 of about 749,140 (312)

Tower impulse grounding resistance measurement based on multiple frequency impedance

IET Generation, Transmission & Distribution, 2023
Tower impulse grounding resistance is important for judging the lightning protection performance of transmission lines. Therefore, it is significant to accurately measure the tower impulse grounding resistance. Existing measurement methods mainly contain
Yihua Dan, Ruixuan Zhang, Yongye Wu, Yiqiao Li, Xuement Wang, Jian Yang   +5 more
doaj   +3 more sources

Respiratory impedance measured using impulse oscillometry in a healthy urban population [PDF]

ERJ Open Research, 2021
This study derives normative prediction equations for respiratory impedance in a healthy asymptomatic urban population using an impulse oscillation system (IOS).
Kenneth I. Berger, Margaret Wohlleber, Roberta M. Goldring, Joan Reibman, Mark R. Farfel, Stephen M. Friedman, Beno W. Oppenheimer, Steven D. Stellman, James E. Cone, Yongzhao Shao   +9 more
doaj   +4 more sources

Research on impulse impedance model and protection optimization of transmission tower grounding device in mountainous area

IET Science, Measurement & Technology, 2021
The impulse impedance of the tower is the core parameter to evaluate the lightning protection performance of the transmission line. The high soil resistivity and the underground rock layers in the mountainous areas will induce large impulse impedance and
Lin Huang, Lijun Zhou, Dong Zhang, Dongyang Wang, Weifu Gu, Sixiang Chen   +5 more
doaj   +2 more sources

Transient impedance of grounding system with impulse superimposed sinewave

ENP Engineering Science Journal, 2021
Investigating the transient performance of grounding systems subject to lightning (impulse or impulse superimposed sinewave) is valuable for protecting the power system and maintaining the system operation.
Sherif Ghoneim, Ahdab Elmorshedy, Rabah Amer   +2 more
doaj   +3 more sources

Reference values of respiratory impedance with impulse oscillometry in healthy Chinese adults [PDF]

Journal of Thoracic Disease, 2020
Abstract Background: Impulse oscillometry (IOS) is a non-invasive pulmonary function test for measuring respiratory impedance. Available reference equations of IOS indices for adults are limited. The aim of this study was to develop reference equations of IOS indices for Chinese adults.Methods: In a multicentral, cross-sessional study of ...
Xiaolin Liang, Yi Gao, Weijie Guan, Jing Du, Li Chen, Wen Han, Jinming Liu, Yong Lu, Yi Peng, Bingrong Zhao, Tao wang, Jinping Zheng   +11 more
openaire   +3 more sources

Respiratory system impedance in different decubitus evaluated by impulse oscillometry in individuals with obesity.

PLoS ONE, 2023
Background and objectiveThe body posture can influence gas exchange, respiratory mechanics, and mucociliary clearance and different positions can be used as a therapeutic strategy to improve in gas exchange and can also help physiotherapists to assist ...
Mayara Holtz, Larissa Perossi, Jéssica Perossi, Daniele Oliveira Dos Santos, Hugo Celso Dutra de Souza, Ada Clarice Gastaldi   +5 more
doaj   +2 more sources

Impulse Characteristics of Soil Treated with Enhancement Materials and Various Moisture Contents

Applied Sciences
Due to the high mineral contents of additives and enhancement materials (EMs), EMs have become popular in treating soil, which expectedly improves the electrical characteristics of soil.
Usman Muhammad, Fazlul Aman, Normiza Mohamad Nor   +2 more
doaj   +2 more sources

Modeling of different tower grounding systems using hybrid continuous circuit-trapezoidal integration method [PDF]

Serbian Journal of Electrical Engineering, 2021
In order to protect the transmission lines against lightning strikes, it is important to investigate the tower grounding system. In this paper, a recent method called hybrid continuous circuit-trapezoidal integration method is used to calculate ...
Asadpourahmadchali Mohammadbagher, Niasati Mohsen, Alinejad-Beromi Yousef   +2 more
doaj   +1 more source

Back flashover mitigation for transmission tower by parallel additional multiple conductors from tower top to ground footage to alter the surge impedance

Energy Reports, 2022
This research assessed the transmission tower’s surge impedance before and after paralleling the overhead ground wire (OHGW) made of twisted galvanized steel cable from topmost of the transmission tower to the tower ground footage.
Chakkri Satchathampitak, Rongrit Chatthaworn, Amnart Suksri   +2 more
doaj   +1 more source

Evaluation principle and method of horizontal grounding electrode based on time‐varying impedance

IET Science, Measurement & Technology, 2021
The length of the horizontal grounding electrode is usually extended to decrease the impulse grounding resistance. In this paper, the mechanism for influencing the effective length is revealed by studying the dispersal process of a horizontal electrode ...
Xiaobin Cao, Ming Wei, Manxiang Wang, Jiacai Liu, Ruifang Li, Lin Yang   +5 more
doaj   +1 more source