Detection Of Explosive Gases Research Articles

A novel coupling-activated GO nanocomposites based on surface acoustic wave for assessing capture molecules and detection of explosive gases

Surface acoustic wave (SAW) technology has been widely used in the field of hazardous gas detection, but there are still many problems to be solved such as long response/recovery time, poor selectivity and repeatability. In this study, we evaluated the adsorption capacity of various explosive capture molecules using SAW devices and designed a sensing material for 2,4,6-trinitrotoluene (TNT) gas detection by coupling 4-aminothiophenol (PATP), which has the best adsorption capacity, to activated graphene oxide (GO) via a disulfide exchange scheme. The SAW sensor based on graphene oxide/2-(2-Pyridyldisulfide) ethylamine hydrochloride/4-aminothiophenol (GO/PDEA/PATP) has a theoretical detection limit (DL) as low as 2.8 ppb, short response/recovery time (15/45 s < ), good repeatability, stability selectivity and interference immunity. The enhanced mechanism for its high sensitivity and selectivity detection for TNT is based on the formation of a "Meisenheimer" complex by multiple strong interactions between PATP and TNT. Of course, the formation of this complex also leads to incomplete recovery of the sensor in high TNT concentrations. The scientific findings of this work will provide new idea for exploring the next generation of acoustic gas-phase explosives sensors.

Ultra-highly sensitive optical gas sensors based on chemomechanical polymer-incorporated fiber interferometer

We demonstrate a novel optical sensor for use in explosive gas detection, having a simple structure, ultrahigh sensitivity, room-temperature sensing/refreshing operation, and no local power requirements. The sensor relies on a fiber Fabry-Pérot interferometer prepared using poly(4-vinylpyridine), which induces cavity expansion upon absorption of nitrobenzene, thereby shifting the phase matching conditions of the resonating modes. An estimated sensitivity limit as low as 5 ppb was achieved.

Complex system reliability estimation methodology in the absence of failure data

AbstractThis paper presents a comprehensive system reliability estimation methodology for cases when failure data are unavailable, at least initially. In this methodology, the laws of physics and thermal fundamentals are used to establish a mathematical model that relates the influential input operating characteristics, such as material properties and geometry, to system performance measures. Probability distributions for each influential operating characteristic, identified from the available manufacturing data, information found in instruction manuals and related technical journals, and expert knowledge, are used to simulate the system behavior with Monte Carlo simulation. An initial reliability estimate is obtained by comparing the simulated system performance with the permissible system performance. Fuzzy logic is used to incorporate the impact of environmental factors on the performance of the simulated system performance and hence the system reliability. Finally, with the use of Bayesian analysis, initial system reliability is updated to take into account the effect of environmental factors. The proposed methodology is applied to estimate the reliability of the hazardous gas detection system used in aerospace shuttles for the timely detection of explosive gases. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Explosive gas detection and applications.

AbstractIndustry is becoming more aware of the hazards to life and property that accompany the use of flammabl gases and vapors. These problems are becoming so complex that specialized knowledge is necessary to guarantee proper selection of equipment and to maintain the equipment after installation. The selection and use of explosive gas detection equipment should be a coordinated effort between the Safety Engineering and Instrument Engineering Departments. Combustible gas analyzers using the principles of catalytic combusion exhibit the simplicity, flexibility and stability of operation which are the ideal requirements for solvent extraction installations.