Download or read book Simulation of the Environmental Fate and Transport of Chemical Signatures from Buried Landmines written by and published by . This book was released on 1998 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fate and transport of chemical signature molecules that emanate from buried landmines is strongly influenced by physical chemical properties and by environmental conditions of the specific chemical compounds. Published data have been evaluated as the input parameters that are used in the simulation of the fate and transport processes. A one-dimensional model developed for screening agricultural pesticides was modified and used to simulate the appearance of a surface flux above a buried landmine and estimate the subsurface total concentration. The physical chemical properties of TNT cause a majority of the mass released to the soil system to be bound to the solid phase soil particles. The majority of the transport occurs in the liquid phase with diffusion and evaporation driven advection of soil water as the primary mechanisms for the flux to the ground surface. The simulations provided herein should only be used for initial conceptual designs of chemical pre-concentration subsystems or complete detection systems. The physical processes modeled required necessary simplifying assumptions to allow for analytical solutions. Emerging numerical simulation tools will soon be available that should provide more realistic estimates that can be used to predict the success of landmine chemical detection surveys based on knowledge of the chemical and soil properties, and environmental conditions where the mines are buried. Additional measurements of the chemical properties in soils are also needed before a fully predictive approach can be confidently applied.
Download or read book Environmental Fate and Transport of Chemical Signatures from Buried Landmines Screening Model Formulation and Initial Simulations written by and published by . This book was released on 1997 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fate and transport of chemical signature molecules that emanate from buried landmines is strongly influenced by physical chemical properties and by environmental conditions of the specific chemical compounds. Published data have been evaluated as the input parameters that are used in the simulation of the fate and transport processes. A one-dimensional model developed for screening agricultural pesticides was modified and used to simulate the appearance of a surface flux above a buried landmine, estimate the subsurface total concentration, and show the phase specific concentrations at the ground surface. The physical chemical properties of TNT cause a majority of the mass released to the soil system to be bound to the solid phase soil particles. The majority of the transport occurs in the liquid phase with diffusion and evaporation driven advection of soil water as the primary mechanisms for the flux to the ground surface. The simulations provided herein should only be used for initial conceptual designs of chemical pre-concentration subsystems or complete detection systems. The physical processes modeled required necessary simplifying assumptions to allow for analytical solutions. Emerging numerical simulation tools will soon be available that should provide more realistic estimates that can be used to predict the success of landmine chemical detection surveys based on knowledge of the chemical and soil properties, and environmental conditions where the mines are buried. Additional measurements of the chemical properties in soils are also needed before a fully predictive approach can be confidently applied.
Download or read book Chemical Detection of Buried Landmines written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of all the buried landmine identification technologies currently available, sensing the chemical signature from the explosive components found in landmines is the only technique that can classify non-explosive objects from the real threat. In the last two decades, advances in chemical detection methods has brought chemical sensing technology to the foreground as an emerging technological solution. In addition, advances have been made in the understanding of the fundamental transport processes that allow the chemical signature to migrate from the buried source to the ground surface. A systematic evaluation of the transport of the chemical signature from inside the mine into the soil environment, and through the soil to the ground surface is being explored to determine the constraints on the use of chemical sensing technology. This effort reports on the results of simulation modeling using a one-dimensional screening model to evaluate the impacts on the transport of the chemical signature by variation of some of the principal soil transport parameters.
Download or read book Chemical Sensing for Buried Landmines Fundamental Processes Influencing Trace Chemical Detection written by and published by . This book was released on 2002 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include: landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.
Download or read book Forensic and Environmental Detection of Explosives written by Jehuda Yinon and published by John Wiley & Sons. This book was released on 1999-09-09 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Das erste Buch, das forensische und umweltspezifische Aspekte von Explosivstoffen miteinander verbindet! Dieser Leitfaden für Polizei, Umwelt- und gerichtsmedizinische Labors und fortgeschrittene Studenten der einschlägigen Fachrichtungen beschäftigt sich mit dem Nachweis von Explosivstoffen in Luftfrachtgütern, Gepäck, Fahrzeugen, verdächtigen Personen sowie in Boden- und Wasserproben. (08/99)
Download or read book Environmental Impacts to the Chemical Signature Emanating from Buried Unexploded Ordnance written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of locating buried UXO and land mines is a significant challenge to science and technology. Technology development efforts are under way to use chemical sensors that can discriminate inert ordnance and clutter from live munitions that continue to be a threat. However, the chemical signature is affected by multiple environmental phenomena that can enhance or reduce its presence and transport behavior, and can affect the distribution of the chemical signature in the environment. For example, the chemical among these phases, including the spatial distribution, is the key in designing appropriate detectors, e.g., gas, aqueous or solid phase sampling instruments. A fundamental understanding of the environmental conditions that affect the chemical signature is needed to describe the favorable and unfavorable conditions of a chemical detector based survey to minimize the consequences of a false negative.
Download or read book Trace Chemical Sensing of Explosives written by Ronald L. Woodfin and published by John Wiley & Sons. This book was released on 2006-12-15 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely book covers the most recent developments in the chemical detection of explosives in a variety of environments. Beginning with a broad view of the need for and the potential applications of chemical sensing, the book considers the issue of how to effectively include chemical sensing into systems designed to find hidden explosives devices. Offering a firsthand look at the latest technologies direct from those who are actively developing them, the book features: A look at the history of the field, including the contributions of recent programs A brief explanation of the chemistry of various explosives and differences in the place where they may be detected An introduction to the problems presented by trace element sensing An overview and comparison of the technologies currently being used and developed Case studies of field experiences with chemical sensors A look at the emerging threat of non-traditional explosives This book is an important reference for explosives engineers, systems engineers involved in the development of related devices, government agencies and NGOs involved in demining efforts, military and law enforcement specialists in mines and explosive ordinance disposal (EOD), as well as environmental scientists and chemists involved in explosives research. In addition to providing field workers with knowledge that will help them decide where and how to search for explosives using chemical sensors. It will provide them with an understanding of the potential and the limitations of chemical sensing in their search for and identification of dangerous devices.
Download or read book Detection and Remediation Technologies for Mines and Minelike Targets written by and published by . This book was released on 1998 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Symposium on Technology and the Mine Problem written by and published by . This book was released on 2004 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Noses and Sensors for the Detection of Explosives written by J. Gardner and published by Springer Science & Business Media. This book was released on 2004-08-17 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Research Workshop, held in Warwick, Coventry, U.K., 30 September-3 October 2003
Download or read book Canines written by Lauryn E. DeGreeff and published by CRC Press. This book was released on 2022-01-31 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detection canines have been utilized throughout the world for over a century, and while numerous attempts have been made to replicate the canine’s ability to detect substances by mechanical means, none has been as successful. The olfactory system is a highly intricate and sophisticated design for chemical sensing, and the olfactory capacity of many animals, including canines, is considered unmatched by machine due to not only their great sensitivity and superior selectivity but also their trainability and mobility. These unique features have led to the use of such animals as "whole-animal" biosensors. Amplifying the benefits and diminishing the limitations of detection canines' interdisciplinary research is crucial to understanding canine olfaction and detection and enhancing this powerful and complex detector. The past 50 years have produced vast advancements in animal behavior/training technology to develop canines into more proficient and reliable sensors, while scientific research has provided tremendous support to help practitioners better understand how to utilize this powerful sensor. This book assembles a diverse group of authors with expertise in a variety of fields relating to detection canines and the chemical sensing industry, including both research and operational perspectives on detection canines. It illustrates how science enhances our understanding of how canines are employed for solving some of the world’s leading detection challenges.
Download or read book Effect of Weather on the Predicted PMN Landmine Chemical Signature for Kabul Afghanistan written by and published by . This book was released on 2002 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Buried landmines are often detected through the chemical signature in the air above the soil surface by mine detection dogs. Environmental processes play a significant role in the chemical signature available for detection. Due to the shallow burial depth of landmines, the weather influences the release of chemicals from the landmine, transport through the soil to the surface, and degradation processes in the soil. The effect of weather on the landmine chemical signature from a PMN landmine was evaluated with the T2TNT code for Kabul, Afghanistan. Results for TNT and DNT gas-phase and soil solid-phase concentrations are presented as a function of time of the day and time of the year.
Download or read book Journal of Mine Action written by and published by . This book was released on 2003 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 1999 Department of Energy Environmental management and commercial waste management written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1998 with total page 1228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 1999 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 1998 with total page 1258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Transport in Porous Media written by Clifford K. Ho and published by Springer Science & Business Media. This book was released on 2006-10-07 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: CLIFFORD K. HOAND STEPHEN W. WEBB Sandia National Laboratories, P. O. Box 5800, Albuquerque, NM 87185, USA Gas and vapor transport in porous media occur in a number of important applications includingdryingofindustrialandfoodproducts,oilandgasexploration,environm- tal remediation of contaminated sites, and carbon sequestration. Understanding the fundamental mechanisms and processes of gas and vapor transport in porous media allows models to be used to evaluate and optimize the performance and design of these systems. In this book, gas and vapor are distinguished by their available states at stan- ? dard temperature and pressure (20 C, 101 kPa). If the gas-phase constituent can also exist as a liquid phase at standard temperature and pressure (e. g. , water, ethanol, toluene, trichlorothylene), it is considered a vapor. If the gas-phase constituent is non-condensable at standard temperature and pressure (e. g. , oxygen, carbon di- ide, helium, hydrogen, propane), it is considered a gas. The distinction is important because different processes affect the transport and behavior of gases and vapors in porous media. For example, mechanisms specific to vapors include vapor-pressure lowering and enhanced vapor diffusion, which are caused by the presence of a g- phase constituent interacting with its liquid phase in an unsaturated porous media. In addition, the “heat-pipe” exploits isothermal latent heat exchange during evaporation and condensation to effectively transfer heat in designed and natural systems.
