Download or read book Ultraviolet Resonant Raman Enhancements in the Detection of Explosives written by and published by . This book was released on 2009 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultraviolet Resonance Raman Enhancements in the Detection of Explosives written by and published by . This book was released on 2009 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (nonresonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided ~2000-fold enhancement at 244 nm and ~800-fold improvement at 229 nm while PETN showed a maximum of ~25-fold at 244 nm and ~190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as v4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

Download or read book Standoff Ultraviolet Raman Scattering Detection of Trace Levels of Explosives written by and published by . This book was released on 2011 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultraviolet (UV) Raman scattering with a 244-nm laser is evaluated for standoff detection of explosive compounds. The measured Raman scattering albedo is incorporated into a performance model that focused on standoff detection of trace levels of explosives. This model shows that detection at ≈100 m would likely require tens of seconds, discouraging application at such ranges, and prohibiting search-mode detection, while leaving open the possibility of short-range point-and-stare detection. UV Raman spectra are also acquired for a number of anticipated background surfaces: tile, concrete, aluminum, cloth, and two different car paints (black and silver). While these spectra contained features in the same spectral range as those for TNT, we do not observe any spectra similar to that of TNT.

Download or read book Laser Based Optical Detection of Explosives written by Paul M. Pellegrino and published by CRC Press. This book was released on 2018-09-03 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-Based Optical Detection of Explosives offers a comprehensive review of past, present, and emerging laser-based methods for the detection of a variety of explosives. This book: Considers laser propagation safety and explains standard test material preparation for standoff optical-based detection system evaluation Explores explosives detection using deep ultraviolet native fluorescence, Raman spectroscopy, laser-induced breakdown spectroscopy, reflectometry, and hyperspectral imaging Examines photodissociation followed by laser-induced fluorescence, photothermal methods, cavity-enhanced absorption spectrometry, and short-pulse laser-based techniques Describes the detection and recognition of explosives using terahertz-frequency spectroscopic techniques Each chapter is authored by a leading expert on the respective technology, and is structured to supply historical perspective, address current advantages and challenges, and discuss novel research and applications. Readers are left with an in-depth understanding and appreciation of each technology’s capabilities and potential for standoff hazard detection.

Download or read book UV Excited Resonance Raman Spectroscopy of Narcotics and Explosives written by HS. Sands and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 244 nm excitation Raman microspectroscope has been developed and successfully used to investigate a range of narcotics and explosives, both pure and contaminated. The instrument is quick and simple to operate and effective in identifying these compounds. The wavelength was chosen to exploit the resonance Raman effect, thereby enhancing the band intensities beyond the normal v4 enhancement associated with the shorter wavelength excitation. Another advantage over visibly excited Raman spectroscopy is the complete lack of any fluorescence background, even with heavily contaminated samples. The simplification of spectra caused by resonance allowed the easy identification of species contained in complex mixtures.

Download or read book Resonant Enhanced Raman Spectroscopy for Explosives Detection written by Anneli Ehlerding and published by . This book was released on 2009 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resonance Enhanced Raman Spectroscopy for Explosives Detection written by Ida Johansson and published by . This book was released on 2009 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resonance Enhanced Raman Spectroscopy for Explosives Detection written by Ida Johansson and published by . This book was released on 2010 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detection of Liquid Explosives and Flammable Agents in Connection with Terrorism written by Hiltmar Schubert and published by Springer Science & Business Media. This book was released on 2008-05-21 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The organization of an Advanced Research Workshop with the title “Detection and Disposal of Liquid Explosives and Flammable Agents in Connection with Terrorism” was motivated by international findings about activities in this field of application. This ARW followed a meeting about the “Detection of Disposal Improvised Explosives” (St. Petersburg, 2005). Both items show the logistic problems as one of the lessons, terrorists have to overcome. These problems are connected with the illegal supply and transport of explosives and fuels and as counter-measure the detection of these materials. The invention of liquid explosives goes back to the middle of the 19th century and was used for special purposes in the commercial field of application. Because of the high sensitivity of liquid explosives against mechanical shock, caused by adiabatic compression of air-bobbles producing “hot spots” as origin of initiation the commercial application was not very successful. Because of this high risk, liquid explosives are not used in military or commercial application with some exceptions. In the commercial field explosives as slurries or emulsions consisting of suitable salts (Ammoniumnitrate etc.) and water are used to a large extend because of their high insensitivity. In many cases these slurries or emulsions were unfit for terrorist actions, because of their low sensitivity, large critical diameter and using in confinement. In the military field liquid explosives are used in World War I and II as bomb-fillings.

Download or read book SWOrRD Swept Wavelength Resonance Raman Detection of Bacteria Chemical and Explosives written by and published by . This book was released on 2010 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detection of bacteria, chemicals or explosives with Raman scattering is fast, noncontact, does not require chemical supplies and is adaptable to robotic vehicles; making Raman ideal for many military and civilian applications. In this technique, a laser is used to illuminate an area which may contain the sought after substance. Some of the laser light is absorbed by the molecular vibrational and rotational states of the substance, and is re-emitted (scattered) at wavelengths slightly different than the wavelength of the illuminating laser.

Download or read book Resonance Enhanced Raman Spectroscopy for Explosive Detection Evaluation of Solution Experiments written by Ida Johansson and published by . This book was released on 2008 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Counterterrorist Detection Techniques of Explosives written by Jehuda Yinon and published by Elsevier. This book was released on 2011-10-13 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detection of hidden explosives has become an issue of utmost importance in recent years. While terrorism is not new to the international community, recent terrorist attacks have raised the issue of detection of explosives and have generated a great demand for rapid, sensitive and reliable methods for detecting hidden explosives. Counterterrorist Detection Techniques of Explosives covers recent advances in this area of research including vapor and trace detection techniques (chemiluminescence, mass spectrometry, ion mobility spectrometry, electrochemical methods and micromechanical sensors, such as microcantilevers) and bulk detection techniques (neutron techniques, nuclear quadrupole resonance, x-ray diffraction imaging, millimeter-wave imaging, terahertz imaging and laser techniques). This book will be of interest to any scientists involved in the design and application of security screening technologies including new sensors and detecting devices which will prevent the smuggling of bombs and explosives. * Covers latest advances in vapor and trace detection techniques and bulk detection techniques* Reviews both current techniques and those in advanced stages of development* Techniques that are described in detail, including its principles of operation, as well as its applications in the detection of explosives

Download or read book Frontiers of Molecular Spectroscopy written by Jaan Laane and published by Elsevier. This book was released on 2011-08-11 with total page 741 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of what we know about atoms, molecules, and the nature of matter has been obtained using spectroscopy over the last one hundred years or so. In this book we have collected together twenty chapters by eminent scientists from around the world to describe their work at the cutting edge of molecular spectroscopy. These chapters describe new methodology and applications, instrumental developments, and theory which is taking spectroscopy into new frontiers. The range of topics is broad. Lasers are utilized in much of the research, but their applications range from sub-femtosecond spectroscopy to the study of viruses and also to the investigation of art and archeological artifacts. Three chapters discuss work on biological systems and three others represent laser physics. The recent advances in cavity ringdown spectroscopy (CRDS), surface enhanced Raman spectroscopy (SERS), two-dimensional correlation spectroscopy (2D-COS), and microwave techniques are all covered. Chapters on electronic excited states, molecular dynamics, symmetry applications, and neutron scattering are also included and demonstrate the wide utility of spectroscopic techniques. Provides comprehensive coverage of present spectroscopic investigations Features 20 chapters written by leading researchers in the field Covers the important role of molecular spectroscopy in research concerned with chemistry, physics, and biology

Download or read book Explosives Detection Via Stand Off Raman Spectroscopy written by Bernhard Zachhuber and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-05 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing worldwide threat of terrorism requires the capability of sytems to remotely detect and identify explosives. A stand-off Raman system was built and optimised which meets these demands including the identification of substances concealed in opaque containers. To meet the challenging situations in real life, explosives and their precursors were analysed in the presence of interfering substances and on a variety of background materials, including plastics or different car doors. The influence of the laser excitation wavelength was also investigated. The stand-off distance was successfully extended to 100 metres at a testing ground at the Austrian Armed Forces. The combination of stand-off Raman with spatial offset Raman scattering has enabled the identification and quantification of substances up to 40 metres in packaging which is non-transparent to the human eye. An alternative way to probe substances inside turbid bottles was found by using depth-resolved stand-off Raman spectroscopy. This methodology employs the speed of light to distinguish between samples located at different distances from the setup.

Download or read book Ultraviolet Resonance Raman Investigations of Excited State Structure and Dynamics of L 3 dienes written by Mark Oluf Trulson and published by . This book was released on 1987 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Enhanced Vibrational Spectroscopy written by Ricardo Aroca and published by John Wiley & Sons. This book was released on 2006-05-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Enhanced Vibrational Spectroscopy (SEVS) has reached maturity as an analytical technique, but until now there has been no single work that describes the theory and experiments of SEVS. This book combines the two important techniques of surface-enhanced Raman scattering (SERS) and surface-enhanced infrared (SEIR) into one text that serves as the definitive resource on SEVS. Discusses both the theory and the applications of SEVS and provides an up-to-date study of the state of the art Offers interpretations of SEVS spectra for practicing analysts Discusses interpretation of SEVS spectra, which can often be very different to the non-enhanced spectrum - aids the practicing analyst

Download or read book Vibrational Spectroscopy in Diagnosis and Screening written by IOS Press (Firm) and published by IOS Press. This book was released on 2012-06-15 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years there has been a tremendous growth in the use of vibrational spectroscopic methods for diagnosis and screening. These applications range from diagnosis of disease states in humans, such as cancer, to rapid identification and screening of microorganisms. The growth in such types of studies has been possible thanks to advances in instrumentation and associated computational and mathematical tools for data processing and analysis. This volume of Advances in Biomedical Spectroscopy contains chapters from leading experts who discuss the latest advances in the application of Fourier transform infrared (FTIR), Near infrared (NIR), Terahertz and Raman spectroscopy for diagnosis and screening in fields ranging from medicine, dentistry, forensics and aquatic science. Many of the chapters provide information on sample preparation, data acquisition and data interpretation that would be particularly valuable for new users of these techniques including established scientists and graduate students in both academia and industry.