scholarly journals Large‐eddy simulations of neutrally stratified airflow over the complex terrain around Hong Kong International Airport with a three‐runway system

2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Louis K. S. Tse ◽  
K. K. Hon ◽  
Larry K. B. Li
Keyword(s):  
Hong Kong ◽  
Complex Terrain ◽  
Large Eddy Simulations ◽  
International Airport ◽  
Large Eddy ◽  
Hong Kong International Airport ◽  
Neutrally Stratified

scholarly journals Radiological features of body packers: An experience from a regional accident and emergency department in close proximity to the Hong Kong International Airport

2018 ◽  
Vol 25 (4) ◽  
pp. 202-210
Author(s):  
Ho Kai Patrick Tsang ◽  
Cheuk Kei Kathy Wong ◽  
Oi Fung Wong ◽  
Wing Lun William Chan ◽  
Hing Man Ma ◽  
...  
Keyword(s):  
Emergency Department ◽  
Hong Kong ◽  
Body Packing ◽  
Radiological Features ◽  
International Airport ◽  
Accident And Emergency ◽  
Accident And Emergency Department ◽  
Body Packers ◽  
Solid Form ◽  
Hong Kong International Airport

Background: Body packing is a frequently used method for drug trafficking. Local information about the clinical and radiological features of body packing is lacking. Objectives: To evaluate the radiological features of body packers presenting to a hospital near to the Hong Kong International Airport and to compare the radiological features of solid form versus liquid cocaine. Methods: This was a retrospective cohort study. Medical notes of 269 suspected body packers, presenting to the Accident and Emergency Department of North Lantau Hospital under the detention by the law enforcement personnel from 1st January 2015 to 28th February 2017, were reviewed. The radiological features of body packing were retrospectively evaluated. Results: Sixty-nine cases were confirmed body packers radiographically. Majority of them (81%, 56/69) were cocaine packers. Powder form cocaine (67%, 49/69) was the most popular drug packed, followed by liquid cocaine (15%, 10/69). There was a trend of increasing incidence of liquid cocaine packers. The classical ‘double condom’, ‘tic tac’ and ‘halo’ signs were present in 94%, 72.5% and 42% of cases with radiologically confirmed body packing respectively. The ‘rosette’ sign was only identified in 1 case. Three new radiological signs, the ‘bag of eggs’, ‘lucent triangle’ and ‘black crescent’ sign, were suggested to aid identification of drug packets. The classical ‘tic tac’ sign was absent in all liquid cocaine packing cases (p<0.05). The liquid cocaine packets appeared irregular with indistinct border in majority of cases (p<0.05). The solid form packets were mostly opaque to faeces while liquid cocaine had variable density (p<0.05). Most solid form packets had homogeneous content which was in contrast to the heterogeneous content in liquid cocaine (p<0.05). Conclusion: Failure in detecting drug body packing may result in medicolegal consequences. Emergency physicians need to be aware of subtle radiological signs of liquid cocaine packets in the plain abdominal radiography.

scholarly journals Large-Eddy Simulations of Real-World Episodes in Complex Terrain Based on ERA-Reanalysis and Validated by Ground-Based Remote Sensing Data

2019 ◽  
Vol 147 (12) ◽  
pp. 4325-4343 ◽  
Author(s):  
Cornelius Hald ◽  
Matthias Zeeman ◽  
Patrick Laux ◽  
Matthias Mauder ◽  
Harald Kunstmann
Keyword(s):  
Remote Sensing ◽  
Boundary Conditions ◽  
Complex Terrain ◽  
Computing Time ◽  
Remote Sensing Data ◽  
Large Eddy Simulations ◽  
Small Scale ◽  
Sensing Data ◽  
Large Eddy ◽  
Local Weather

Abstract A computationally efficient and inexpensive approach for using the capabilities of large-eddy simulations (LES) to model small-scale local weather phenomena is presented. The setup uses the LES capabilities of the Weather Research and Forecasting Model (WRF-LES) on a single domain that is directly driven by reanalysis data as boundary conditions. The simulated area is an example for complex terrain, and the employed parameterizations are chosen in a way to represent realistic conditions during two 48-h periods while still keeping the required computing time around 105 CPU hours. We show by evaluating turbulence characteristics that the model results conform to results from typical LES. A comparison with ground-based remote sensing data from a triple Doppler-lidar setup, employed during the “ScaleX” campaigns, shows the grade of adherence of the results to the measured local weather conditions. The representation of mesoscale phenomena, including nocturnal low-level jets, strongly depends on the temporal and spatial resolution of the meteorological boundary conditions used to drive the model. Small-scale meteorological features that are induced by the terrain, such as katabatic flows, are present in the simulated output as well as in the measured data. This result shows that the four-dimensional output of WRF-LES simulations for a real area and real episode can be technically realized, allowing a more comprehensive and detailed view of the micrometeorological conditions than can be achieved with measurements alone.

Sign in / Sign up

Export Citation Format

Share Document