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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Preventing chemical weapons as sciences converge

Crowley, Michael J.A., Shang, Lijun, Dando, Malcolm R. 16 November 2018 (has links)
Yes / Stark illustrations of the dangers from chemical weapons can be seen in attacks using toxic industrial chemicals and sarin against civilians and combatants in Syria and toxic industrial chemicals in Iraq, as well as more targeted assassination operations in Malaysia and the United Kingdom, employing VX and novichok nerve agents, respectively. Concerns about such malign applications of chemical technology are exacerbated by the unstable international security environment and the changing nature of armed conflict, “where borderlines between war, civil war, large-scale violations of human rights, revolutions and uprisings, insurgencies and terrorism as well as organized crime are blurred” (1). It is thus essential that the global community regularly review the nature and implications of developments in chemistry, and its convergence with the life and associated sciences, and establish appropriate measures to prevent their misuse. With the parties to the Chemical Weapons Convention (CWC) convening a Review Conference to address such issues beginning 21 November 2018, we highlight important scientific aspects (2)
2

High Flow Air Sampling for Field Detection Using Gas Chromatography-Mass Spectrometry

Murray, Jacolin Ann 01 December 2010 (has links) (PDF)
The ability to rapidly detect and identify hazardous analytes in the field has become increasingly important. One of the most important analytical detection methods in the field is gas chromatography-mass spectrometry (GC-MS). In this work, a hand-portable GC-MS system is described that contains a miniature toroidal ion trap mass analyzer and a low thermal mass GC. The system is self-contained within the dimensions of 47 x 36 x 18 cm and weighs less than 13 kg. Because the instrument has a small footprint, it was used as the detector for an automated near-real-time permeation testing system. In permeation testing, materials that are used to make individual protective equipment such as gloves, masks, boots, and suits are exposed to hazardous analytes to determine how long the equipment can be worn safely. The system described herein could test five samples simultaneously. A multi-position valve rotated among the various sample streams and delivered time aliquots into the MS for quantitation. Current field air sampling techniques suffer from long desorption times, high pressure drops, artifact formation and water retention. These disadvantages can be avoided by concentrating the analytes in short open tubular traps containing thick films. There are several advantages to using polymer coated capillaries as traps, including fast desorption, inertness and low flow restriction. An air sampling trap was constructed utilizing open tubular traps for the concentration of semi-volatile organic compounds. The system consisted of multiple capillary traps bundled together, providing high sample flow rates. The analytes were desorbed from the multi-capillary bundle and refocused in a secondary trap. The simultaneous focusing and separation effect of a trap subjected to a negative temperature gradient was also explored. In this configuration, analytes were focused because the front of the peak was at a lower temperature than the rear of the peak and, hence, moved slower. In addition to the focusing effect, analytes with different volatilities focused at different temperatures within the gradient, allowing for separation.
3

Applications of Chemometric Algorithms to Ion Mobility Spectrometry and Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Chen, Ping 18 July 2008 (has links)
No description available.

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