An Explosion of a CNG Fuel Vessel in an Urban Bus

Abstract: An investigation is presented of the explosion of a CNG (compressed natural gas) fuel vessel, called a liner, in an urban bus. The explosion happened at a gas station 10 min after filling was completed. There were no traces of soot and flames at the failed liner, which would be indicative of explosion by ignition of the gas. The filling process of the station was automatically monitored and recorded in a computer. There was no unusual record of the filling system that indicated excess pressure at the time of the accident. There were cracks on the liner that were initiated at the outer surface of the cylindrical shell located at a point 4 cm above the lower dome where cracks did not originate easily as a result of overload. Chemical analysis was performed on a specimen that was cut from the liner, and there was no peculiarity in the mix. Mechanical analysis was performed on the specimens and showed that the hardness was not in the specified range because of inadequate heat treatment of the metal. The hardness of the liner was strictly controlled in the manufacturing process. All the liners that were manufactured at the same period with the failed liner were recalled for examination.     

Application of 3D Laser Scanner to Forensic Engineering

In the case of building collapses and overturned structures, a three‐dimensional (3D) collapse or overturn model is required to reconstruct the accident. As construction sites become increasingly complex and large, 3D laser scanning is sometimes the best tool to accurately document and store the site conditions. This case report presents one case of a structure collapse and one case of an overturned crane reconstructed by a 3D laser scanner. In the case of structural collapse of a prefabricated shoring system, a 3D model reconstructed all the members successfully, a task that is nearly impossible using a scale such as a tape measure. The reconstructed prefabricated shoring system was verified through a structural analysis through comparison with the construction drawings to investigate faults in construction. In the case of the overturned crane, the jib angle and other major dimensions were successfully acquired through 3D laser scanning and used to estimate the working radius. As a result, the propriety of the working radius with the given lifting load was successfully determined.     

The determination of tetraalkyl lead compounds in petrol using combined gas chromatography-atomic absorption spectrometry

The use of a gas chromatograph equipped with an atomic absorption spectrophotometer as a detector is described for the determination of tetraalkyl lead compounds in petrol. Generally, a significant variation in the ratios of the tetraalkyl lead species was observed in the samples studied, but in samples of petrol from service stations that had obtained their supplies from only one refinery, a small variation in the ratios was found.     

Book review

Andrew Linklater and the New Rhetoric in International Relations

Andrew Linklater, The Transformation of Political Community (Cambridge: Polity Press, 1998), 263 pp.     

Democratization in turmoil? Elections in Hong Kong

The first SAR Chief Executive, Tung Chee‐hwa, in his speech at the SAR Establishment Ceremony, said: ‘Democracy is the hallmark of a new era for Hong Kong. The SAR Government will resolutely move forward to a more democratic form of government in accordance with the provisions in the Basic Law’. Butler, Penniman and Ranney, however, cautioned that ‘the critical difference between democratic and nondemocratic regimes is to be found in whether or not they hold elections, and if they do, what kind’. Indeed, electoral changes made to the 1998 LegCo elections are found to be anti‐democratic and retrogressive, as well as unnecessary. The authors conclude that electoral systems matter because they are one of the central mechanisms in modern democracies to give substance and content to democratic governance. If electoral systems are designed in such a manner that they obstruct the exercise of popular sovereignty, ride rough‐shod over the principle of political equality, undermine the extent of representation, complicate relationships of accountability as well as delimit opportunities for participation, then such systems should have little place in genuine democratic reform. To bring Hong Kong's democratization forward, a hard look at the electoral system, which should be more informed by the principles and practices of democracy will be mandatory.     

An epidemiological study on alcohol/drugs related fatal traffic crash cases of deceased drivers in Hong Kong between 1996 and 2000

This study is designed to evaluate the correlation between fatal vehicle crashes (FVC) and consumption of alcohol and/or drugs among drivers. Between 1996 and 2000 in Hong Kong, a total of 197 FVC cases of deceased drivers were investigated. The blood and/or urine samples of the victims were examined for the presence of alcohol and drugs. The 197 cases were then classified into two groups: single-vehicle crashes (SVC) and multiple-vehicle crashes (MVC). Out of the 106 cases for the latter group, alcohol and/or drugs were detected in 22 cases (21%) while the remaining 84 cases (79%) were regarded as no significant finding. As for the 91 cases in SVC group, 51 cases (56%) were positive for alcohol and/or drugs. The findings indicate that a driver consuming alcohol and/or drugs has a higher risk of being involved in a FVC. The most frequently detected drugs for SVC group (11 cases) were: 46% central nervous system (CNS) stimulants (including designer drugs like MDMA); 36% cannabis; 18% benzodiazepines and 9% ketamine. The detected drug for the only case in the MVC group was a CNS stimulant. The number of cases with ketamine, methamphetamine and MDMA detected has increased in recent years as these party drugs have gained popularity in Hong Kong.     

Impurity profiling of ecstasy tablets seized in Hong Kong by gas chromatography-mass spectrometry

In Hong Kong, ecstasy tablets are more commonly known as "Fing Tau Yuen", literally meaning "Shake Head Pills". The tablets contain mainly amphetamine-type stimulants (ATS) including 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MA) and/or ketamine. Adulterant such as caffeine was also detected in the tablets. This paper reports a study on the impurity profiles of ecstasy tablets from 89 seizures in Hong Kong from 2002 to early 2004. Tablet samples were extracted by diethyl ether under alkaline condition and then analyzed by gas GC-MS. The chromatograms obtained were compared. A total of 19 identified impurities were selected as markers for impurity profiling. They are different precursors, intermediates and by-products. The data matrices were examined by hierarchical cluster analysis (HCA), and then the ecstasy tablets were classified into different groups. Cluster analysis of ecstasy tablets is shown to be capable of providing intelligence on clandestine laboratory networks.     

Conductive Activism: Anti-Sweatshop Campaigns across Hong Kong and Mainland China

This study looks at trans-border, anti-sweatshop campaigns and the transformation of cross-border activism between Hong Kong and mainland China. Examining two cases, it demonstrates the mechanism and processes of trans-border, anti-sweatshop campaigns and networks involving non-governmental agencies, student groups and workers. The study suggests that anti-sweatshop activism has been conductive and transferrable from Hong Kong to China in a way that has mobilised local civil society power, cultivated mainland activists and nurtured localised pro-labour activism. With Hong Kong activists acting as movement conveyers and mainland activists acting as adapters, anti-sweatshop activism has evolved. Once centred on marketplaces and consumers, it is now centred on production sites, and has moved domestic actors (including workers, students, scholars, media and consumers) from the margins to the centre. Anti-sweatshop activism has moulded itself to local contexts by rebuilding its strategies and tactics while coalescing with overseas networks to integrate strengths across the Hong Kong-Chinese border. Although the anti-sweatshop movement in China has its weaknesses, its evolution has the potential to gradually alter the power asymmetries between domestic and overseas activists.