Download or read book The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this study is to evaluate cavity ringdown spectroscopy (CRDS) as an ultrasensitive technique for trace analysis of metals. Potential applications of CRDS to meet stated Department of Energy needs include: Mercury Continuous Emission Monitor Multi-Metal Emissions Monitor Radionuclide Detector and Monitor A full description of the technique can be found in Ref. 1. Briefly, CRDS is based upon the measurement of the rate of light absorption in a closed optical cavity. PMT Cavity Mirror Sample Cavity Mirror Laser Pulse A laser pulse is injected into a stable optical cavity through one of the cavity mirrors. This light pulse is trapped between the mirror surfaces and decays exponentially over time at a rate determined by the round trip losses within the cavity. When used for trace analysis, the primary loss mechanisms governing the decay time are mirror reflectivity losses, atomic absorption from the sample, and Rayleigh scattering from air in the cavity. The decay time is given by t = d c 1- R () +als + bd (1) where d is the cavity length, R is the reflectivity of the cavity mirrors, a is the familiar Beer's Law absorption coefficient of a sample in the cavity, ls is the length of the optical path through the sample (i.e., approximately the graphite furnace length), b is the wavelength-dependent Rayleigh scattering attenuation coefficient, and c is the speed of light. Thus, variations in a caused by changes in the sample concentration are reflected in the ringdown time. As the sample concentration increases (i.e., a increases), the ringdown time decreases yielding an absolute measurement for a. With the use of suitable mirrors, it is possible to achieve thousands of passes through the sample. This results in an effective path length reaching into the kilometers and a corresponding increase in sensitivity. An additional benefit is that it is not subject to collisional 2 quenching and the branching that occur in techniques such as laser-excited atomic fluorescence (LEAFS).
Download or read book The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: A critical need exists for the development of methods to monitor toxic metal concentrations in remediation system off gases in real-time at parts-per-billion levels or lower. Although several technology development projects are being pursued to meet the requirements of a multi-element metals continuous emission monitor (CEM), no current technique has met all the requirements of sensitivity and data quality. The use of cavity ringdown spectroscopy (CRS) as an ultra-sensitive analytical technique is a natural extension of previous atomic absorption spectroscopy methods. However, while CRS has rapidly gained popularity among the molecular spectroscopy community, the work reported here concerns the first efforts to apply this technique to analytical atomic spectroscopy. The objective of this project is to combine CRS with the well-established tools for sample atomization, the inductively coupled plasma (ICP) and graphite furnace (GF), to provide a viable technique for on-line, trace level continuous emission monitoring of species such as toxic metals and radionuclides with detection limits comparable to ICP-mass spectroscopy (ICP-MS). This report summarizes the authors progress in the first year of a 3-year project to develop cavity ringdown spectroscopy as a sensitive, continuous emission monitor for metals. Progress has been slightly delayed by problems associated with freeing up the matching funds necessary to purchase a new narrow-linewidth dye laser and the typical problems encountered when departments move into a new building. However, these problems have been largely solved. Their new laser system has recently arrived and additional matching funds have been obtained for the purchase of a graphite furnace. This instrument is on order and will arrive in the near future. The postdoctoral and graduate positions have been filled.
Download or read book The Development of Cavity Ringdown Spectroscopy as a Toxic Metal Continuous Emission Monitor written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovative program to explore the viability of using Cavity Ringdown Spectroscopy (CRDS) for trace analysis and monitoring of remediation processes for hazardous and radioactive wastes. Cavity ringdown spectroscopy is a measurement of the rate of absorption of a sample within a closed optical cavity rather than the standard measurement of the avsorved signal strength over a given sample path. It is a technique capable of providing ultra-sensitive absorption measurements in hostile environments using commercially available easy-to-use pulsed lasers. The inherent high sensitivity stems from both the long effective sample pathlengths possible and the relaxed constraints on the accuracy of the measurement of the cavity decay time.
Download or read book Research Opportunities for Managing the Department of Energy s Transuranic and Mixed Wastes written by National Research Council and published by National Academies Press. This book was released on 2002-11-07 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: About 155,000 cubic meters of waste contaminated with both radioactive isotopes and hazardous chemicals are stored at some 30 DOE sites, and another 450,000 cubic meters are buried. While DOE is making a concerted effort to properly dispose of this waste, the amount translates to a multi-decade effort that will require handling, characterizing, and shipping hundreds of thousands of waste containers at a total cost of billions of dollars. This report describes basic scientific research that can lead to new technologies for performing these tasks more safely and cost effectively.
Download or read book Research Needs for High Level Waste Stored in Tanks and Bins at U S Department of Energy Sites written by National Research Council and published by National Academies Press. This book was released on 2001-10-05 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Department of Energy (DOE) has approximately 400 million liters (100 million gallons) of liquid high-level waste (HLW) stored in underground tanks and approximately 4,000 cubic meters of solid HLW stored in bins. The current DOE estimate of the cost of converting these liquid and solid wastes into stable forms for shipment to a geological repository exceeds $50 billion to be spent over several decades (DOE, 2000). The Committee on Long-Term Research Needs for Radioactive High-Level Waste at Department of Energy Sites was appointed by the National Research Council (NRC) to advise the Environmental Management Science Program (EMSP) on a long-term research agenda addressing the above problems related to HLW stored in tanks and bins at DOE sites.
Download or read book Engineering Aspects of Magnetohydrodynamics written by and published by . This book was released on 1997 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavity ringdown Spectroscopy written by Kenneth W. Busch and published by . This book was released on 1999 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavity-ringdown spectroscopy is an emerging method for making high sensitivity absorption measurements with gas-phase samples. This volume, the first devoted to the method, covers the history, theory, and numerous applications. Written by leaders in the field, it is a comprehensive guide to current methods and ongoing research.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavity Ring Down Spectroscopy written by Giel Berden and published by John Wiley & Sons. This book was released on 2009-08-11 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavity Ring-Down Spectroscopy: Techniques and Applications provides a practical overview of this valuable analytical tool, explaining the fundamental concepts and experimental methods, and illustrating important applications. Designed as both an introductory text and a reference source, this book is relevant for scientists unfamiliar with CRDS who are interested in using the technique in their research, as well as experienced users.
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1994 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Green Electronics written by Cristian Ravariu and published by BoD – Books on Demand. This book was released on 2018-06-20 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Green Electronics book is intended to stimulate people's thinking toward the new concepts of an environment-friendly electronics - the main challenge in the future. The book offers multiple solutions to push the classical electronic industry toward green concepts, aided by nanotechnologies, with revolutionary features that provide low power consumption in electronics, use biomaterials for integrated structures, and include environmental monitoring tools. Based on organic semiconductors/insulators without toxic precursors, green electronic technologies launched promising devices like OLED, OTFT, or nano-core-shell transistors. The Green Electronics book successfully presents the recent directions collected worldwide and leaves free space for continuing year by year with new subtopics.
Download or read book Applied Spectroscopy written by and published by . This book was released on 2007 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2017 International Conference on Unmanned Aircraft Systems ICUAS written by IEEE Staff and published by . This book was released on 2017-06-13 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Present state of the art advances, research and development in the area of unmanned aviation Educate faculty, students, scientists, engineers, researchers, practitioners, end users and the public about UAS Advance knowledge frontier in the area of UAS Couple technology advances with public policy, legal and ethical issues and privacy Provide the framework for integration of UAS into the national airspace design and build the next generation of unmanned systems that are safe, reliable and resilient
Download or read book Improving Characterization of Anthropogenic Methane Emissions in the United States written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2018-08-25 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding, quantifying, and tracking atmospheric methane and emissions is essential for addressing concerns and informing decisions that affect the climate, economy, and human health and safety. Atmospheric methane is a potent greenhouse gas (GHG) that contributes to global warming. While carbon dioxide is by far the dominant cause of the rise in global average temperatures, methane also plays a significant role because it absorbs more energy per unit mass than carbon dioxide does, giving it a disproportionately large effect on global radiative forcing. In addition to contributing to climate change, methane also affects human health as a precursor to ozone pollution in the lower atmosphere. Improving Characterization of Anthropogenic Methane Emissions in the United States summarizes the current state of understanding of methane emissions sources and the measurement approaches and evaluates opportunities for methodological and inventory development improvements. This report will inform future research agendas of various U.S. agencies, including NOAA, the EPA, the DOE, NASA, the U.S. Department of Agriculture (USDA), and the National Science Foundation (NSF).
Download or read book Advances in Spectroscopic Monitoring of the Atmosphere written by Weidong Chen and published by Elsevier. This book was released on 2021-06-09 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Spectroscopic Monitoring of the Atmosphere provides a comprehensive overview of cutting-edge technologies and monitoring applications. Concepts are illustrated by numerous examples with information on spectroscopic techniques and applications widely distributed throughout the text. This information is important for researchers to gain an overview of recent developments in the field and make informed selections among the most suitable techniques. This volume also provides information that will allow researchers to explore implementing and developing new diagnostic tools or new approaches for trace gas and aerosol sensing themselves. Advances in Spectroscopic Monitoring of the Atmosphere covers advanced and newly emerging spectroscopic techniques for optical metrology of gases and particles in the atmosphere. This book will be a valuable reference for atmospheric scientists, including those whose focus is applying the methods to atmospheric studies, and those who develop instrumentation. It will also serve as a useful introduction to researchers entering the field and provide relevant examples to researchers and students developing and applying optical sensors for a variety of other scientific, technical, and industrial uses. Overview of new applications including remote sensing by UAV, laser heterodyne radiometry, dual comb spectroscopy, and more Features in-situ observations and measurements for real-world data Includes content on leading edge optical sensors
Download or read book Optics in Our Time written by Mohammad D. Al-Amri and published by Springer. This book was released on 2016-12-12 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light and light based technologies have played an important role in transforming our lives via scientific contributions spanned over thousands of years. In this book we present a vast collection of articles on various aspects of light and its applications in the contemporary world at a popular or semi-popular level. These articles are written by the world authorities in their respective fields. This is therefore a rare volume where the world experts have come together to present the developments in this most important field of science in an almost pedagogical manner. This volume covers five aspects related to light. The first presents two articles, one on the history of the nature of light, and the other on the scientific achievements of Ibn-Haitham (Alhazen), who is broadly considered the father of modern optics. These are then followed by an article on ultrafast phenomena and the invisible world. The third part includes papers on specific sources of light, the discoveries of which have revolutionized optical technologies in our lifetime. They discuss the nature and the characteristics of lasers, Solid-state lighting based on the Light Emitting Diode (LED) technology, and finally modern electron optics and its relationship to the Muslim golden age in science. The book’s fourth part discusses various applications of optics and light in today's world, including biophotonics, art, optical communication, nanotechnology, the eye as an optical instrument, remote sensing, and optics in medicine. In turn, the last part focuses on quantum optics, a modern field that grew out of the interaction of light and matter. Topics addressed include atom optics, slow, stored and stationary light, optical tests of the foundation of physics, quantum mechanical properties of light fields carrying orbital angular momentum, quantum communication, and Wave-Particle dualism in action.
