A two-stage combustor facility is used to investigate methylene chloride (CH2Cl2) incineration an... more A two-stage combustor facility is used to investigate methylene chloride (CH2Cl2) incineration and formation of products of incomplete combustion (PIC). For measuring low concentrations of CH2Cl2, on-line microtrap gas chromatography is employed. Destruction efficiency of CH2Cl2 over a wide range of feed concentrations was investigated under fuel-lean and fuel-rich ethylene/air combustion conditions. The impact of CH2Cl2 on the formation of
This paper describes our current research in the area of staged combustion, wherein the overall f... more This paper describes our current research in the area of staged combustion, wherein the overall fuel-lean system is divided into a fuel-rich (oxidant lean) first stage followed by a fuel-lean (oxidant rich) second stage. The first stage of our turbulent flow combustor is a jet-stirred, backmixed zone which can be modeled as a perfectly stiffed reactor (PSR) under most conditions. The effluent from this zone enters a linear flow zone which can be modeled as a plug flow reactor (PFR). Industrial turbulent combustors, incinerators, and afterburners which employ a central fuel nozzle and swirled concentric air for flame stabilization can often be modeled with this sequence.
ABSTRACT Recently, there has been a significant interest in employing Terahertz (THz) technology,... more ABSTRACT Recently, there has been a significant interest in employing Terahertz (THz) technology, spectroscopy and imaging for standoff detection applications. There are three prime motivations for this interest: (a) THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to THz radiation, (b) target compounds such as explosives, and bio/chemical weapons have characteristic THz spectra that can be used to identify these compounds and (c) THz radiation poses no health risk for scanning of people. This paper will provide an overview of THz standoff detection of explosives and weapons including discussions of effective range, spatial resolution, and other limitations. The THz approach will be compared to alternative detection modalities such as x-ray and millimeter wave imaging.
The chemistry leading to products of incomplete combustion, as affected by chlorocarbons, was stu... more The chemistry leading to products of incomplete combustion, as affected by chlorocarbons, was studied by modeling data from a jet-stirred reactor, verifield experimentally to be at nearly perfectly-stirred conditions. Premixed, fuel-rich mixtures of C2H4, CH3Cl, and air were burned in a toroidal jet-stirred combustor. Instantaneous measurements of local temperature were obtained using laser Rayleigh scattering. and extractive probe sampling followed
The paper describes a combined approach of bench and pilot scale experiments that is revealing ne... more The paper describes a combined approach of bench and pilot scale experiments that is revealing new insights into the complex interactions between chemical reaction and mixing which affect product of incomplete combustion (PIC) emissions and secondary combustion chamber (SCC) performance. The bench scale reactor allows well defined experiments which are relatively easy to control and inexpensive. The pilot scale reactor allows experiments under near-commercial scale SCC conditions. Using its volatile organics sampling train (VOST)-like sampling and gas chromatography (GC) systems, combustion products are analyzed with high sensitivity, but at low costs and short turnaround times.
International Journal of High Speed Electronics and Systems, Jun 1, 2007
Experimental results of homodyne terahertz interferometric 1-D and 2-D imaging are presented. The... more Experimental results of homodyne terahertz interferometric 1-D and 2-D imaging are presented. The reconstructed images of a point source are in a good agreement with theoretical predictions. The performance of an N element detector array is imitated by only one detector placed at N positions. Continuous waves at 0.25-0.3 THz are used to detect a metal object behind a barrier. 1-D images of a C-4 sample have been obtained at several terahertz frequencies. Focusing issues of 2-D imaging have been demonstrated. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.
A two-stage combustor facility is used to investigate methylene chloride (CH2Cl2) incineration an... more A two-stage combustor facility is used to investigate methylene chloride (CH2Cl2) incineration and formation of products of incomplete combustion (PIC). For measuring low concentrations of CH2Cl2, on-line microtrap gas chromatography is employed. Destruction efficiency of CH2Cl2 over a wide range of feed concentrations was investigated under fuel-lean and fuel-rich ethylene/air combustion conditions. The impact of CH2Cl2 on the formation of
This paper describes our current research in the area of staged combustion, wherein the overall f... more This paper describes our current research in the area of staged combustion, wherein the overall fuel-lean system is divided into a fuel-rich (oxidant lean) first stage followed by a fuel-lean (oxidant rich) second stage. The first stage of our turbulent flow combustor is a jet-stirred, backmixed zone which can be modeled as a perfectly stiffed reactor (PSR) under most conditions. The effluent from this zone enters a linear flow zone which can be modeled as a plug flow reactor (PFR). Industrial turbulent combustors, incinerators, and afterburners which employ a central fuel nozzle and swirled concentric air for flame stabilization can often be modeled with this sequence.
ABSTRACT Recently, there has been a significant interest in employing Terahertz (THz) technology,... more ABSTRACT Recently, there has been a significant interest in employing Terahertz (THz) technology, spectroscopy and imaging for standoff detection applications. There are three prime motivations for this interest: (a) THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to THz radiation, (b) target compounds such as explosives, and bio/chemical weapons have characteristic THz spectra that can be used to identify these compounds and (c) THz radiation poses no health risk for scanning of people. This paper will provide an overview of THz standoff detection of explosives and weapons including discussions of effective range, spatial resolution, and other limitations. The THz approach will be compared to alternative detection modalities such as x-ray and millimeter wave imaging.
The chemistry leading to products of incomplete combustion, as affected by chlorocarbons, was stu... more The chemistry leading to products of incomplete combustion, as affected by chlorocarbons, was studied by modeling data from a jet-stirred reactor, verifield experimentally to be at nearly perfectly-stirred conditions. Premixed, fuel-rich mixtures of C2H4, CH3Cl, and air were burned in a toroidal jet-stirred combustor. Instantaneous measurements of local temperature were obtained using laser Rayleigh scattering. and extractive probe sampling followed
The paper describes a combined approach of bench and pilot scale experiments that is revealing ne... more The paper describes a combined approach of bench and pilot scale experiments that is revealing new insights into the complex interactions between chemical reaction and mixing which affect product of incomplete combustion (PIC) emissions and secondary combustion chamber (SCC) performance. The bench scale reactor allows well defined experiments which are relatively easy to control and inexpensive. The pilot scale reactor allows experiments under near-commercial scale SCC conditions. Using its volatile organics sampling train (VOST)-like sampling and gas chromatography (GC) systems, combustion products are analyzed with high sensitivity, but at low costs and short turnaround times.
International Journal of High Speed Electronics and Systems, Jun 1, 2007
Experimental results of homodyne terahertz interferometric 1-D and 2-D imaging are presented. The... more Experimental results of homodyne terahertz interferometric 1-D and 2-D imaging are presented. The reconstructed images of a point source are in a good agreement with theoretical predictions. The performance of an N element detector array is imitated by only one detector placed at N positions. Continuous waves at 0.25-0.3 THz are used to detect a metal object behind a barrier. 1-D images of a C-4 sample have been obtained at several terahertz frequencies. Focusing issues of 2-D imaging have been demonstrated. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.
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