Remote-sensing observations of a gust front at Hong Kong International Airport

Weather ◽  
2012 ◽  
Vol 67 (7) ◽  
pp. 176-181 ◽  
Author(s):  
P. W. Chan
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 ◽  
...  

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.


2008 ◽  
Vol 25 (5) ◽  
pp. 637-655 ◽  
Author(s):  
C. M. Shun ◽  
P. W. Chan

Abstract In December 2005, operational wind shear alerting at the Hong Kong International Airport (HKIA) reached an important milestone with the launch of the automatic Lidar (light detection and ranging) Windshear Alerting System (LIWAS). This signifies that the anemometer-based and radar-based wind shear detection technologies deployed worldwide in the twentieth century have been further advanced by the addition of the lidar—a step closer to all-weather coverage. Unlike the microburst and gust front, which have a well-defined coherent vertical structure in the lowest several hundred meters of the atmosphere, terrain-induced wind shear tends to have high spatial and temporal variability. To detect the highly changeable winds to be encountered by the aircraft under terrain-induced wind shear situations, the Hong Kong Observatory devises an innovative glide path scan (GPScan) strategy for the lidar, pointing the laser beam toward the approach and departure glide paths, with the changes in azimuth and elevation angles concerted. The purpose of the GPScans is to derive the headwind profiles and hence the wind shear along the glide paths. Developed based on these GPScans, LIWAS is able to capture about 76% of the wind shear events reported by pilots over the most-used approach corridor under clear-air conditions. During the past two years, further developments of the lidar took place at HKIA, including the use of runway-specific lidar to further enhance the wind shear detection performance.


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