Results 61 to 70 of about 293,197 (180)

Patent arterial duct occlusion with two amplatzer duct occluder devices [PDF]

, 2011
It is accepted practice to close large patent arterial ducts (PDA) with Amplatzer duct occluder devices, with extremely low rates of residual PDA. This article reports a child who required device closure of PDA with two Amplatzer PDA devices on two ...
DeGiovanni, Joseph V., Grech, Victor E.
core  

Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones. [PDF]

, 2015
Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications.
Morris, S, Gurusamy, KS, Davidson, BR, Kurinchi S Gurusamy, Jessica Sheringham (708860), Stephen Morris (324510), Stephen Morris, Sheringham, J, Brian R Davidson, Brian R. Davidson (496581), Jessica Sheringham, Kurinchi S. Gurusamy (496578), Sheringham Jessica, Morris Stephen, Gurusamy Kurinchi S., Davidson Brian R.   +15 more
core   +1 more source

Investigating the Role of Wave Process in the Evaporation Duct Simulation by Using an Ocean–Atmosphere–Wave Coupled Model

Atmosphere
In this study, a diagnostic model for evaporation ducts was established based on the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) and the Naval Postgraduate School (NPS) models.
Zhigang Shan, Miaojun Sun, Wei Wang, Jing Zou, Xiaolei Liu, Hong Zhang, Zhijin Qiu, Bo Wang, Jinyue Wang, Shuai Yang   +9 more
doaj   +1 more source

Comparison of evaporation duct models to compute duct height over Arabian sea and Bay of Bengal

, 2002
155-158Various models exist that calculate evaporation duct height in terms of directly measureable meteorological parameters in the surface layer over the sea-surface.
Sarkar, S K, Pasricha, P K, Prasad, M V S N   +2 more
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Refractivity variations and propagation at Ultra High Frequency

Results in Physics, 2017
Present framework is established to deal with the refractivity variations normally affected the radio waves propagation at different frequencies, ranges and different environments.
I. Alam, M. Najam-Ul-Islam, U. Mujahid, S.A.A. Shah, Rizwan Ul Haq   +4 more
doaj   +1 more source

IPILT–OHPL: An Over-the-Horizon Propagation Loss Prediction Model Established by Incorporating Prior Information Into the LSTM–Transformer Structure

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
The evaporation duct is a prevalent atmospheric structure in the marine lower troposphere with significant regional nonuniformity. This structure can trap radio waves inside its layer and enable them to propagate over the horizon with less loss ...
Hanjie Ji, Lixin Guo, Jinpeng Zhang, Yiwen Wei, Xiangming Guo, Yusheng Zhang, Tianhang Nie, Jie Feng   +7 more
doaj   +1 more source

FADING CHARACTERISTICS OF EVAPORATION DUCT FOR AVAILABILITY & CAPACITY OF THE WIRELESS COMMUNICATION LINK OVER THE SEA

, 2018
High-Capacity and reliable communication over the sea surface has always been a challenge due to vast distances. Evaporation ducts (ED) caused by the rapid decrease in the refractive index of the lower atmosphere, are known to trap radio waves between ...
ZAIDI, KHURRAM SHABIH
core  

Evaporation-Duct-Aware Joint Communication–Navigation Trajectory Optimization for Multi-Waypoint Maritime Missions

IEEE Open Journal of Vehicular Technology
Reliable long-range maritime communication remains challenging for shore-based systems due to the radio-horizon limitation and the strong spatial variability of sea-surface propagation.
Hao Zhang, Ruifeng Gao, Jue Wang, Ye Li, Yingdong Hu, Qiuming Zhu, Shu Sun, Meixia Tao   +7 more
doaj   +1 more source

Characterization and Estimation of Evaporation Duct Strength Under Tropical Cyclone Conditions Using Stacking Ensemble Learning

Remote Sensing
Tropospheric evaporation ducts can trap radio waves within a refractive layer, which may guide signals above 1 GHz, enabling beyond-line-of-sight transmission. This makes duct-assisted propagation attractive for maritime communications.
Jinzi Ma, Jian Wang, Cheng Yang, Wenlu Liu, Jiaying Shang   +4 more
doaj   +1 more source

Efficient computation of spinning modal radiation through an engine bypass duct

, 2008
The aim of this work is to accurately and efficiently predict sound radiation out of a duct with flow. The sound propagation inside a generic engine bypass duct, refractions by the shear layer of the exhaust flow, and propagation in the near field are ...
Zhang, Xin, Chen, Xiaoxian, Ma, Zhaokai, Huang, Xun, X. Zhang, Z. Ma, X. Huang, X. Chen   +7 more
core   +1 more source