Results 21 to 30 of about 17,042 (262)

False-positive diagnosis of pulmonary hypertension by Doppler echocardiography [PDF]

European Respiratory Journal, 1998
A 37-yr-old female presented with a history of several months of exertional dyspnoea. A diagnosis of primary pulmonary hypertension was suspected on the basis of a negative extensive cardiorespiratory work-up with a systolic pulmonary artery pressure of 41-46 mmHg calculated from repeated measurement of the maximum velocity of tricuspid regurgitation ...
Vachiery, Jean-Luc, Brimioulle, Serge, Crasset, Vincent, Naeije, Robert   +3 more
openaire   +2 more sources

New method for airborne SAR image positioning

The Journal of Engineering, 2019
Synthetic aperture radar (SAR) geometric positioning obtains the geodetic coordinates of each pixel in a SAR image. However, due to the changes in geometry, position and attitude angle of the sensor and the influence factors such as topography ...
Ding Wang, Aifang Liu, Xue Xia
doaj   +1 more source

Accuracy of Doppler Determinations of Station Positions [PDF]

Symposium - International Astronomical Union, 1972
Locations of Doppler satellite observing stations have been revised to obtain a set which is more self-consistent and more consistent with the CIO pole. Residuals of satellite observations for 1970 have been analyzed using the new coordinates to determine mean and standard errors for five days of observations of latitude versus station, time of day ...
openaire   +1 more source

Microstructural Evolution and Vacancy Defect Formation in Mn–Mo–Ni RPV Steel Under Low Cycle Fatigue: Insights From EBSD and PALS

Advanced Engineering Materials, EarlyView.
Low‐cycle fatigue damage in Mn–Mo–Ni reactor pressure vessel steel is examined using a combined electron backscatter diffraction and positron annihilation lifetime spectroscopy approach. The study correlates texture evolution, dislocation substructure development, and vacancy‐type defect formation across uniform, necked, and fracture regions, providing
Apu Sarkar, Dhanadeep Dutta, G. Bharat Reddy   +2 more
wiley   +1 more source

Influence of an Argon/Silane Atmosphere on the Temperature of a Thermal Plasma

Advanced Engineering Materials, EarlyView.
The influence of a silane‐doped argon atmosphere on the chemical composition and temperature of a thermal nontransferring argon plasma is investigated using optical emission spectroscopy. As a result of the high amount of free electrons resulting from the stepwise ionization and dissociation of the silane molecule, even a silane addition of 0.01 vol ...
Lena Kreie, David Kramer, Thomas Scheithauer, Hans Jürgen Maier, Thomas Hassel   +4 more
wiley   +1 more source

Survey on positioning technology based on signal of opportunity from low earth orbit

Frontiers in Physics
Positioning, Navigation, and Timing (PNT) services are essential for supporting various aspects of modern society. Fields such as communications, transportation, and military operations heavily rely on accurate and reliable PNT services, with this ...
Jiawei He, Jiawei He, Shaojie Ni, Shaojie Ni, Honglei Lin, Honglei Lin, Zhe Liu, Zhe Liu, Zhibin Xiao, Zhibin Xiao   +9 more
doaj   +1 more source

Accuracy analysis for passive localization from frequency measurements using single satellite

Advances in Mechanical Engineering, 2017
A simple method of passive localization is proposed in this article. The proposed approach is located a on the ground or in the air stationary target using the satellites in different signal Doppler frequencies.
Linfu Duan, Haoran Lu, Yan Zhang, Xiansheng Guo, Yebo Guo, Botao Zeng   +5 more
doaj   +1 more source

Acoustic Indoor Localization System Integrating TDMA+FDMA Transmission Scheme and Positioning Correction Technique

Sensors, 2019
This paper presents a novel audio indoor localization system. In the proposed system, four speakers placed at known positions transmit chirp signals according to the time-division multiple access (TDMA) plus frequency-division multiple access (FDMA ...
Xiang Chen, Yuheng Chen, Shuai Cao, Lei Zhang, Xu Zhang, Xun Chen   +5 more
doaj   +1 more source

Direct Position Determination of Coherent Pulse Trains Based on Doppler and Doppler Rate [PDF]

Electronics, 2018
Direct Position Determination (DPD) of coherent pulse trains using a single moving sensor is considered in this paper. Note that when a large observation window and relative maneuvering course between emitter and receiver both exist, the localization accuracy of Doppler frequency shift only based DPD will decline because of the noticeable Doppler ...
Guizhou Wu, Min Zhang, Fucheng Guo, Xuebing Xiao   +3 more
openaire   +1 more source

Drug‐Free Thrombolysis Mediated by Physically Activated Micro/Nanoparticles

Advanced Functional Materials, EarlyView.
Overview of particle‐mediated thrombolytic effects (thermal, mechanical, and chemical) and their activating physical stimuli (light, ultrasound, and magnetic field) in drug‐free thrombolysis. ABSTRACT Thrombus‐associated disorders rank among the world's leading causes of death, with ischemic heart disease and stroke as the main contributors.
Pierre Sarfati, Yoann Lalatonne, Cédric Chauvierre   +2 more
wiley   +1 more source