Desorption electrospray ionization (DESI) is applied to the rapid, in-situ, direct qualitative and quantitative analysis of mixtures of explosives and drugs from a variety of fabrics, including cotton, silk, denim, polyester, rayon, spandex, leather and their blends. The compounds analyzed were explosives: trinitrohexahydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN) and the drugs of abuse: heroin, cocaine, and methamphetamine. Limits of detection are in the picogram range. DESI analyses were performed without sample preparation and carried out in the presence of common interfering chemical matrices, such as insect repellant, urine, and topical lotions. Spatial and depth profiling was investigated to examine the depth of penetration and lateral resolution. DESI was also used to examine cotton transfer swabs used for travel security sample collection in the screening process. High throughput quantitative analysis of fabric surfaces for targeted analytes is also reported.
"Ambient MS methods have the potential to drastically simplify preliminary analyses by eliminating the need for sample preparations , while bolstering the information content by providing mass spectral data without requiring lengthy chromatography steps.        In this capacity, the rapidity of the test along with the high mass accuracy of the time-of-flight (TOF) analyzer would serve in a complementary fashion to traditional confirmatory GC- MS methods, which generally only provide integer mass information . Ambient methods combined with high accuracy instruments have demonstrated the potential to enhance analysis in sports doping, particularly in regards to emerging drugs. "
[Show abstract][Hide abstract] ABSTRACT: The behaviour of a 7.5 kW high efficiency cage induction motor fed
by distorted supply has been investigated in this paper. Experimental
data were collected by developing a testing facility consisting of a
three phase harmonic generator, a double chamber calorimeter and a PC
based data acquisition system. Motor additional losses due to the
presence of harmonics were estimated using the calorimetric method. It
has been shown that a distorted voltage containing low order harmonics
causes more losses in the motor as compared with the high order
harmonics. Accordingly, weighted THD (WTHD) has been defined to specify
the limits for additional losses in a motor supplied by distorted
voltages. The variation of test motor parameters with harmonic order as
well as the variation of additional losses with WTHD has led to
establishment of derating factor (DF) for the test induction motor.
Applicability of the DF on several induction motors with different power
ratings has been examined. It has been demonstrated that with a service
factor of 1.15, most induction motors are capable to handle distorted
voltages as defined by standards
Electrical and Computer Engineering, 2000 Canadian Conference on; 02/2000
[Show abstract][Hide abstract] ABSTRACT: The purpose of the work presented here is to characterise
polymeric HVDC cable insulation consisting of lapped thin film
polypropylene with respect to DC current conduction and partial
discharge activity in air filled butt gaps. The PD activity was found to
strongly increase with increasing temperature and applied electric
stress. The discharge frequency decreased with time after voltage
application and the effect of the void size was found to be of minor
importance. These observations agree very well with the proposed theory
stating that the discharge frequency will be proportional to the current
flowing through the insulation
Solid Dielectrics, 2001. ICSD '01. Proceedings of the 2001 IEEE 7th International Conference on; 02/2001
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