Download or read book Photoacoustic Trace Gas Detection written by Frank Kühnemann and published by . This book was released on 1999 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CO2 Laser Photoacoustic Spectroscopy for Ultrasensitive Gas Detection written by Ana Maria Bratu and published by LAP Lambert Academic Publishing. This book was released on 2014-11-11 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: CO2 Laser Photoacoustic Spectroscopy for Ultrasensitive Gas Detection is an easy-to-read guide to understanding the fundamentals of lasers, experimental method of CO2 laser spectroscopy and applications. This book provide informative data of a functional photoacoustic instrument with various applications in different disciplines. The wide scope of the chapters ranges from descriptions of the method, through the use of breath analysis in the study of physiological phenomena, to the identification of hazardous gases from surgical smoke. This book will provide a solid grounding for physicists, chemists, and engineers involved in trace gas analysis and detection.
Download or read book Photoacoustic Photothermal and Photochemical Processes in Gases written by Peter Hess and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas-phase photoacoustics are treated comprehensively for the first time in this book. Review articles by leading scientists in the respective research areas introduce their fields, review present knowledge and conclude with the latest developments and future prospects. Topics covered include the theory of photoacoustics in the frequency and time domains, acoustic resonator models, a great variety of experimental setups and techniques, studies of spectrocopy and fundamental kinetic processes such as energy transfer and chemical reactions, and applications such as air and exhaust monitoring and trace gas detection in biology and agriculture. The book will interest newcomers to photoacoustics, since it gives an overview of the important directions of current research and detailed descriptions of experimental methods. It will also be a valuable source of information for those already involved in photoacoustic research due to its clear presentation of theory and experimental results. All relevant literature references in this rapidly expanding field of laser applications are included.
Download or read book Refined CO laser Photoacoustic Trace Gas Detection Observation of Anaerobic Processes in Insects Soil and Fruit written by Franciscus Godefridus Casper Bijnen and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Refined CO laser Photoacoustic Trace Gas Detection written by Franciscus Godefridus Casper Bijnen and published by . This book was released on 1995 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis in physics deals with the physical methods of photacoustic trace gas detection applied to fundamental biological subjects. New and improvedexperimental arrangements are presented which allow fast, multi-component and sensitive detection.
Download or read book Photoacoustic Photothermal and Photochemical Processes in Gases written by Peter Hess and published by Springer. This book was released on 2011-12-22 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas-phase photoacoustics are treated comprehensively for the first time in this book. Review articles by leading scientists in the respective research areas introduce their fields, review present knowledge and conclude with the latest developments and future prospects. Topics covered include the theory of photoacoustics in the frequency and time domains, acoustic resonator models, a great variety of experimental setups and techniques, studies of spectrocopy and fundamental kinetic processes such as energy transfer and chemical reactions, and applications such as air and exhaust monitoring and trace gas detection in biology and agriculture. The book will interest newcomers to photoacoustics, since it gives an overview of the important directions of current research and detailed descriptions of experimental methods. It will also be a valuable source of information for those already involved in photoacoustic research due to its clear presentation of theory and experimental results. All relevant literature references in this rapidly expanding field of laser applications are included.
Download or read book Air Monitoring by Spectroscopic Techniques written by Markus W. Sigrist and published by John Wiley & Sons. This book was released on 1994-03-31 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading experts discuss the characteristics, advantages, limitations and future aspects of modern spectroscopic techniques for environmental analysis. Demonstrates how these methods can be applied to trace gas detection and assessment. Concentrates on the latest techniques--both laser and non-laser based--which offer advantages for air pollution and gas monitoring as opposed to more conventional methods. Numerous examples of applications illustrate the potential of the techniques backed up by cutting-edge information and representative data.
Download or read book Photoacoustic and Photothermal Laser Spectroscopy Applied to Trace Gas Detection and Molecular Dynamics written by Irio G. Calasso and published by . This book was released on 1999 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development Characterization and Miniaturization of a Trace Gas Detection System for NO2 in Air Based on Photoacoustic Spectroscopy written by Thomas Rück and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoacoustic Methane Detection Inside a MEMS Microphone written by Thomas Strahl and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: An innovative laser based photoacoustic (PA) gas sensing concept with intrinsic miniaturization potential was developed and investigated for methane trace gas detection. An interband cascade laser (ICL) with an optical power of 8.5 mW targets a methane (CH4) absorption line feature around 3057.7 cm−1 (or 3270 nm). The ICL was focused into the sound port of a MEMS microphone, where the PA signal was generated and detected using a wavelength modulation concept (2f-WMS-PAS). The MEMS microphone was successfully implemented as an intrinsically miniaturized PA cell being gas sensing volume, acoustic resonator and sound transducer at once. Frequencies between 2 kHz and 100 kHz were investigated and used for methane detection. A sensitive and resonant methane detection at 41.8 kHz was investigated by concentration variations between 0 and 10 ppm CH4 in N2. A limit of detection (-LOD) of 329 ppb was estimated. The long term stability of this sensor was investigated by the measurement of methane in ambient air. A noise equivalent concentration (NEC) of 14 ppb (parts per billion) at an average time of 10 s was estimated. This value corresponds to a normalized noise equivalent absorption (NNEA) of W cm−1 Hz−1/2. Using the MEMS microphone directly as PA cell offers the possibility for an extremely miniaturized, highly sensitive and very cost-efficient photoacoustic trace gas sensor
Download or read book Evolution of a MEMS Photoacoustic Chemical Sensor written by and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoacoustic spectroscopy is a useful monitoring technique that is well suited for trace gas detection. The technique also possesses favorable detection characteristics when the system dimensions are scaled to a micro-system design. The objective of present work is to incorporate two strengths of the Army Research Laboratory (ARL), piezoelectric microelectromechanical systems (MEMS) and chemical and biological sensing into a monolithic MEMS photoacoustic trace gas sensor. A miniaturized macro-cell design was studied as a means to examine performance and design issues as the photoacoustics is scaled to a dimension approaching the MEMS level. Initial MEMS work is centered on fabrication of a lead zirconate titanate (PZT) microphone subsystem to be incorporated in the full photoacoustic device. Preliminary results were very positive for the macro-photoacoustic cell, PZT membrane microphones design / fabrication and elementary monolithic MEMS photoacoustic cavity.
Download or read book Photoacoustic Trace Gas Sensing written by Stefan Timotheüs Persijn and published by . This book was released on 2001 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Analytic Solution to a Coupled System of Equations for Modeling Photoacoustic Trace Gas Sensors and a Full Waveform Inversion Approach to Microseismic Source Estimation written by Jordan Kaderli and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss two different problems in applied mathematics. The first is related to the modeling of a certain class of trace gas sensors. The second is the geophysical inverse problem of estimating the source of a microseismic event. Quartz-enhanced photoacoustic spectroscopy and resonant optothermoacoustic detection are two promising techniques used in trace gas sensing. Both methods use a quartz tuning fork and modulated laser source to detect trace gases. We discuss a coupled system of equations for the pressure, temperature, and velocity of a fluid that accounts for both thermal effects and viscous damping. We derive an analytical solution to a pressure-temperature subsystem of the Morse-Ingard equations in the special case of cylindrical symmetry. We solve for the pressure and temperature in an infinitely long cylindrical fluid domain with a source function given by a constant-width Gaussian beam that is aligned with the axis of the cylinder. In addition, we surround this cylinder with an infinitely long annular solid domain, and we couple the pressure and temperature in the fluid domain to the temperature in the solid. We show that the temperature in the solid near the fluid-solid interface can be an order of magnitude larger than that computed using a simpler model in which the temperature is governed by the heat equation. We also verify that the temperature solution of the coupled system exhibits a thermal boundary layer. These results suggest that for computational modeling of resonant optothermoacoustic detection sensors, the temperature in the fluid should be computed by solving the Morse-Ingard equations rather than the heat equation. In the second problem, we use full waveform inversion to estimate the full spatial and temporal description of a microseismic source which includes not only the location and origin time of the source but also the waveform itself. Beginning with the simplifying assumption of two-dimensional acoustic wave propagation, we compute the gradient via the adjoint-state method for both the spatial radiation pattern and the temporal waveform of the source. This approach identifies multiple sources, handles extremely low signal-to-noise ratio data, and produces accurate results in the absence of a good initial estimate. Encouraged by the promising results of the two dimensional acoustic case, we apply the approach to the case where wave propagation is modeled via the velocity-stress formulation of the elastic wave equation in three dimensions. A change of variables applied to the velocity-stress formulation ensures that the system is self-adjoint. Thus full waveform inversion can be effectively tailored to use this transformed velocity-stress system to estimate microseismic events with limited modifications to the forward wave solver. The inversion produces either a spatial source description in the form of a volume in which each point in the domain indicates the magnitude of stress perturbation and therefore deformation of the medium or a temporal source description which gives the time evolution of the deformation. The inversion does not require any a priori assumptions about the form of the source and does not require a good starting guess for accurate source recovery.
Download or read book In situ Atmospheric Trace Gas Monitoring by CO2 Laser Photoacoustic Spectroscopy written by Marc Moeckli and published by . This book was released on 1997 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SF6 Detection Using Laser Pulsed Photoacoustic Spectroscopy Or Trace gas Studies written by Fei Cai and published by . This book was released on 2004 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optoacoustic Spectroscopy and Detection written by Yoh-Han Pao and published by Elsevier. This book was released on 2012-12-02 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoacoustic Spectroscopy and Detection discusses the fundamental principles and practice of optoacoustic spectroscopy. This book serves as a basis for evaluation of the feasibility of using such techniques in specific instances. Organized into eight chapters, this book starts with an overview of the detection and identification of gas contaminants, which is necessary to understand the physical description of the generation and measurement of the optoacoustic signal. This text then provides an understanding of the optoacoustic effect on a molecular scale and describes the energy transfer processes and estimates of the lifetimes of vibrationally excited states. Other chapters consider the options available to the researcher in the selection of optoacoustic system design. This book discusses as well the capabilities and limitations of various optoacoustic system designs. The final chapter deals with the technique used for exploring the absorption spectra of substances, including powders, gels, adsorbed films, and organic tissues. This book is a valuable resource for researchers and graduate students engaged in the study of optoacoustic spectroscopy.
