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 Breath Analysis written by Stefan Weigl and published by Springer Nature. This book was released on 2022-11-14 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights the potentials as well as the limits and challenges of human breath analysis and describes the current efforts made to advance this promising technology from bench to bed. Human breath analysis is a young, interdisciplinary and innovative research field aiming to provide a smart and non-invasive diagnostic tool, which can be used for screening, detecting and monitoring of diseases or metabolic disorders. This book presents different approaches for breath analysis including real-time and offline mass spectrometry as well as optical and semiconductor gas sensing methods. Besides, the role of smart algorithms to improve the performance of those technologies and the importance of pulmonary function diagnostics for more reliable and meaningful breath analysis are highlighted. Finally, current application scenarios and future perspectives of breath analysis and pulmonary functioning tests are addressed. The volume is useful for researchers, who are new in the field, to easily get an overview of the current status and the challenges present in human breath analysis. Topics from fundamental research over targeted sensor development and application scenarios are described. Thus, this volume covers all development stages providing support and inspiration for engineers, medical doctors and scientists from various fields.
Download or read book On Developing a System Analysis Model for Trace Gas Detection Using Pulsed Laser and QEPAS written by Neha Ravindra Sardesai and published by . This book was released on 2013 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the development of a system analysis model for a QEPAS (Quartz Enhanced Photo Acoustic Spectroscopy)-based trace gas detection system with pulsed-laser input and sample-mean test-statistic output. For this QEPAS-based system, the input laser signal is pulsed, and its beam is centered between the tines of a quartz tuning fork placed in a gas cell. If the trace gas is present, it absorbs the energy from the beam, resulting in the generation of an acoustic pressure wave P(r, t). This pressure wave strikes the fork tines causing them to vibrate at resonant frequency. These vibrations result in the flow of current within the tines, due to the piezoelectric effect. On obtaining the current flow signal waveform in the fork, and using statistical signal processing of multiple samples of this waveform, the trace gas can be detected and its concentration estimated. This analysis model will allow one to assess the performance of such a system for various parameter values that define a given system.
Download or read book Innovative Applications and Developments of Micro Pattern Gaseous Detectors written by Francke, Tom and published by IGI Global. This book was released on 2014-04-30 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Study of nature and the world around us has been a primary motivation for scientists and researchers for centuries. Advanced methods in the study of elementary particles have led to even greater discoveries in recent years. Innovative Applications and Developments of Micro-Pattern Gaseous Detectors focuses on the analysis and use of various gas detection systems, providing a detailed description of some of the most commonly used gas detectors and the science behind them. From early detectors to modern tools and techniques, this book will be of particular use to practitioners and researchers in chemical engineering and materials science, in addition to students and academicians concentrating in the field.
Download or read book Development of a Miniaturized Chemiresistive Gas Sensor Based on Carbon Nanomaterials for the Detection of Nitrogen Dioxide in Air written by Fabian Johannes Raphael Aumer and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Towards a Miniaturized Photoacoustic Detector for the Infrared Spectroscopic Analysis of SO2F2 and Refrigerants written by Hassan Yassine and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Sulfuryl fluoride (SO2F2) is a toxic and potent greenhouse gas that is currently widely used as a fumigant insecticide in houses, food, and shipping containers. Though it poses a major hazard to humans, its detection is still carried out manually and only on a random basis. In this paper, we present a two-chamber photoacoustic approach for continuous SO2F2 sensing. Because of the high toxicity of SO2F2, the concept is to use a non-toxic substituent gas with similar absorption characteristics in the photoacoustic detector chamber, i.e., to measure SO2F2 indirectly. The refrigerants R227ea, R125, R134a, and propene were identified as possible substituents using a Fourier-transform infrared (FTIR) spectroscopic analysis. The resulting infrared spectra were used to simulate the sensitivity of the substituents of a photoacoustic sensor to SO2F2 in different concentration ranges and at different optical path lengths. The simulations showed that R227ea has the highest sensitivity to SO2F2 among the substituents and is therefore a promising substituent detector gas. Simulations concerning the possible cross-sensitivity of the photoacoustic detectors to H2O and CO2 were also performed. These results are the first step towards the development of a miniaturized, sensitive, and cost-effective photoacoustic sensor system for SO2F2
Download or read book Gas Detection with Floating Gate Field Effect Transistor written by R. Wahyu Widanarto and published by Cuvillier Verlag. This book was released on 2007 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fundamental and Applied Study of Ionic Liquid based Electrochemical Gas Sensors written by and published by . This book was released on 2017 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation research is mainly focused on the fundamental studies of electrochemical redox behavior of environmental pollution gases in ionic liquid (IL) and the characterization of them using IL as electrolyte for electrochemical gas sensors development. Two gases were investigated: sulfur dioxide (SO2) and nitrogen dioxide (NO2). In addition to the introduction and experimental chapters, this dissertation includes four chapters based on the analyte gases. The electrochemical redox behavior of SO2 gas was studied in three different ILs on three different working electrode (WE) materials. The electrochemical experiment data shows that SO2 can be reduced in ILs to produce SO2− ̇radicals and these SO2− ̇ radicals have multiple electrochemical oxidation passways. The electrochemical quartz crystal microbalance (EQCM) technique which is capable of determining the mass/charge ratio of an electrochemical reaction taking place on the electrode surface was used to support the SO2 redox mechanism hypothesis. Based on the SO2 mechanism study, we also characterized the SO2 detection with different electrochemical methods, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA) which all showed very good sensitivity. The IL-based SO2 sensor also displayed an excellent selectivity and stability toward SO2 detection under ambient conditions. The electrochemical redox behavior of NO2 in IL was also studied. The CV data showed that the NO2 can be reduced in ILs to produce NO2− ions which can be absorbed on the electrode surface. The absorptionstep has been proven to be able to terminate other redox processes on the electrode surface by using O2 gas as the mediator. This absorption is not only good for NO2 gas detection but also beneficial for NO2 capture and NO2 elimination for auto industry lean-burn engine development. The NO2 detection with IL used as electrolyte was also explored with two different mathematical methods for the sensitivity characterization. However, there are many challenges involved in the IL-based electrochemical gas sensor development. The most important one is the accuracy of the potential applied on the WE which is related to the reference electrode (RE) stability. Thus, the development of a new type of polymer based RE for IL electrolyte was also explored. A very good potential stability was achieved with polyaniline (PANI) and polypyrrole (PPy) coated electrodes. In summary, this dissertation work explored the electrochemical redox properties of different gases in ILs and a new type of electrochemical gas sensors based on the IL electrolyte had been developed and characterized. The feasibility of a polymer-based electrode to act as the RE in IL-based electrochemical system was also covered.
Download or read book Sensitive Multi Species Emissions Monitoring written by and published by . This book was released on 2014 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes our development of spectroscopic chemical analysis techniques and spectral modeling for trace-gas measurements of highly-regulated low-concentration species present in flue gas emissions from utility coal boilers such as HCl under conditions of high humidity. Detailed spectral modeling of the spectroscopy of HCl and other important combustion and atmospheric species such as H 2 O, CO 2 , N 2 O, NO 2 , SO 2 , and CH 4 demonstrates that IR-laser spectroscopy is a sensitive multi-component analysis strategy. Experimental measurements from techniques based on IR laser spectroscopy are presented that demonstrate sub-ppm sensitivity levels to these species. Photoacoustic infrared spectroscopy is used to detect and quantify HCl at ppm levels with extremely high signal-to-noise even under conditions of high relative humidity. Additionally, cavity ring-down IR spectroscopy is used to achieve an extremely high sensitivity to combustion trace gases in this spectral region; ppm level CH 4 is one demonstrated example. The importance of spectral resolution in the sensitivity of a trace-gas measurement is examined by spectral modeling in the mid- and near-IR, and efforts to improve measurement resolution through novel instrument development are described. While previous project reports focused on benefits and complexities of the dual-etalon cavity ring-down infrared spectrometer, here details on steps taken to implement this unique and potentially revolutionary instrument are described. This report also illustrates and critiques the general strategy of IR- laser photodetection of trace gases leading to the conclusion that mid-IR laser spectroscopy techniques provide a promising basis for further instrument development and implementation that will enable cost-effective sensitive detection of multiple key contaminant species simultaneously.
Download or read book Micromachined Mixed potential type YSZ based Sensors for Nitrogen Dioxide Monitoring in Automobile Exhaust written by Rui You and published by Springer. This book was released on 2024-08-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents original methods to facilitate the development of micro-mixed-potential-type nitrogen dioxide sensors, especially in the following aspects: (i) improvement of sensing performance of electrodes; (ii) enhancement of chemical activity of reaction interface; (iii) development of advanced flexible low-power-consumption mixed-potential-type YSZ-based nitrogen dioxide sensors. Miniaturized sensors have steadily emerged into the commercial marketplace as competitive alternatives for monitoring and controlling the pollution gas in automobile industry. Despite the great potential, the real-world applications for most conventional micro-nitrogen dioxide sensors are still limited due to insufficient sensitivity, unacceptable cost, and the lack of robustness under harsh environmental disturbances. To address the issue, micro-nitrogen dioxide sensors based on mixed potential solid electrolyte is an ongoing area of great academic and technological interest. This book is expectedto be a guide for researchers on the way forward to chase future horizons in the fields of instrumentation, electrochemistry and micro/nano-electronics.
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 Fabrication Development and Characterization of Micro nano Actuation Based Sensors and Applications for Gas Composition Analysis written by Yang Xu and published by . This book was released on 2006 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro/nano actuation based sensors for gas sensing have generated a great deal of interest due to their ability to detect minute gas concentrations. Currently, gas detection typically relies on changes in cantilever mass or surface stress when a gas interacts with the sensor. Because the detection involves a chemical reaction, the types of gases that can be detected are limited and the detection process is not repeatable and irreversible. Therefore, it is the purpose of this study to develop microresonators, using a new fabrication method, and to investigate the application of these devices as non-reaction based gas sensors.
Download or read book Gas Traces Measurement by Photoacoustic Spectroscopy Using Helmholtz Resonator based Sensors written by Mario Mattiello and published by . This book was released on 2008 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special issue environmental trace gas detection using laser spectroscopy written by and published by . This book was released on 1998 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Trace Gas Detection Instrumentation written by and published by . This book was released on 1973 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Photonic Devices for Trace Gas Sensing and Spectroscopy written by Ali Rostamian and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To keep pace with the ever-increasing demand of integration and miniaturization, it is imperative to redesign conventional optical systems and components and develop new compact ones. Optical spectrometers have been widely adopted as powerful analytical tools showcased by a plethora of applications ranging from medical diagnostics and food analysis to gas and bio-agent sensing and environmental monitoring. Conventional spectroscopy tools require bulky and expensive optical elements, with electronics that result in benchtop systems with limited scope for portability. On-chip spectrometers, on the other hand, are alignment-free and lightweight devices that, unlike their commercially available off-chip counterparts, offer sensing in portable applications and make at-the-sample analysis possible. In this dissertation, chip-scale optical spectrometers with different working principles are studied and implemented. First, an efficient mid-infrared polarization rotator in silicon-on-sapphire is experimentally demonstrated. Since the emission from quantum cascade laser sources is transverse magnetic polarized, this component can be used to convert the polarization state of the light source and couple it into transverse electric photonic components. In chapter 3, we experimentally demonstrate an on-chip Ethyl alcohol sensor based on a holey photonic crystal waveguide on a silicon on insulator platform, offering an enhanced absorption enabled by a slow-light mode and enhanced optical field intensities in the waveguide. In chapter 4, a surface-normal hollow-core photonic crystal waveguide sensor is introduced with a geometry similar to photonic bandgap fibers with perfectly periodic air holes as cladding in a 2-dimensional photonic crystal arrangement that gives rise to bandgaps at specific frequencies and a central defect for strong modal field confinement. On account of the slow-light effect, this device offers a high degree of dispersion control and can be employed for multi-gas detection. Finally, in chapter 5, we present two different devices with single channel geometries that can be used for on-chip spectroscopy. In the first part of this chapter, we present the design and implementation of a cascaded microring-MZI device as a platform for Fourier transform spectroscopy in O-band. In the second part, we demonstrate a device with finely tunable cascaded microdisks offering a platform for on-chip spectroscopy in C-band. Optical devices presented in this dissertation provide a path toward high-performance integrated spectrometers with subcentimeter-scale footprints that enable handheld spectral analysis and more real-life applications
