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- 2018
- interdigital resonator
- microwave gas sensor
- PSE-coated
- Optoelectronic Information Science and Engineering
- King Mongkut’s University of Technology North Bangkok
- Rajamangala University of Technology Suvarnabhumi
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The Use of Copper Oxide Thin Films in Gas-Sensing Applications
摘要： In this work, the latest achievements in the field of copper oxide thin film gas sensors are presented and discussed. Several methods and deposition techniques are shown with their advantages and disadvantages for commercial applications. Recently, CuO thin film gas sensors have been studied to detect various compounds, such as: nitrogen oxides, carbon oxides, hydrogen sulfide, ammonia, as well as several volatile organic compounds in many different applications, e.g., agriculture. The CuO thin film gas sensors exhibited high 3-S parameters (sensitivity, selectivity, and stability). Furthermore, the possibility to function at room temperature with long-term stability was proven as well, which makes this material very attractive in gas-sensing applications, including exhaled breath analysis.
关键词： nanomaterials,gas sensors,exhaled acetone detection,diabetes
更新于2025-09-04 15:30:14
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Enhanced Sensing Performance of Integrated Gas Sensor Devices
摘要： Semiconducting metal oxide (SMO) gas sensors, dedicated to wearable devices were designed, fabricated, and characterized in terms of power consumption, thermal distribution, and sensing capability. The sensors demonstrate a sensitivity down to ppb-level VOC concentrations at a low power consumption of 10.5 mW. To further enhance the baseline stability and sensing response characteristics at low power consumption, a new sensor structure is proposed. The design implements novel aspects in terms of fabrication and microheater geometry, leading to improved sensor performance which enables new applications for SMO gas sensors. In this work, two designs were analyzed using experimental characterization and simulation. The results of the analyses of the two sensors are comparatively reported.
关键词： microheater,electo-thermal simulation,gas sensor,semiconducting metal oxide
更新于2025-09-04 15:30:14
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Ytterbium, You are Cool Enough to Go under the Quantum Gas Microscope!
摘要： Researchers at Kyoto University have developed a novel technique for imaging alkaline-earth atoms using a quantum gas microscope. Ytterbium (Yb) plays an important role in the Atomic, Molecular, and Optical (AMO) physics community because its optical properties are well suited for various applications. The Yb ion is popular as a doping material for fiber lasers and amplifiers. Narrow optical transitions in Yb atoms have been used in optical lattice clock experiments to attain the best performance for optical frequency standards. Now, Shibata et al. claim that a quantum gas of Yb atoms can be studied using a microscope to solve the mystery of strongly correlated gases.
关键词： strongly correlated gases,alkaline-earth atoms,quantum gas microscope,optical lattice,Ytterbium
更新于2025-09-04 15:30:14
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Fluorescent Chemosensor for Quantitation of Multiple Atmospheric Gases
摘要： Recently, the sensing and monitoring of gases from ambient as well as industrial sources has gained a great importance in order to ensure occupational hygiene, public health, and societal welfare. The development of new technologies for visualizing and detecting gases at trace levels is imperative for various applications. There exist several established traditional methods to detect different gases. In this article, we review the latest trends in the area of fluorescence sensing of gas molecules, which is a high sensitivity technique with minimum or negligible interferences. The gas sensors fabricated with the use of fluorescent nanoparticles as detecting elements possess special feature, like high surface-to-volume ratios, ultra sensitivity, enhanced selectivity, cost effectiveness, and fast response. The inherent properties of the related systems, e.g. a large fluorescence lifetime, nanoscale particle size and a tunable zeta potential, make it possible to devise fluorescent sensors with an attractive pathway of fluorescence ‘off–on’. Several fluorimetric methods are known to detect specific gases from the atmospheric gaseous samples with satisfactory detection results. Modern fluorescent gas sensors are did not cause interference from the co-pollutants thus making the fluorimetric sensing process to be quantitative as well as specific.
关键词： Atmospheric environmental sample,Fluorescent gas sensor,Job’s plot,Fluorescent organic nanoparticles,Analytical method,Fluorescence lifetime
更新于2025-09-04 15:30:14
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A brief overview of RF sputtering deposition of boron carbon nitride (BCN) thin films
摘要： A great part of interest has been paid for fabricating new materials with novel mechanical, optical, and electrical properties. Boron carbon nitride (BCN) ternary system was applied for variable bandgap semiconductors and systems with extreme hardness. The purpose of this literature review is to provide a brief historical overview of B4C and BN, to review recent research trends in the BCN synthesizes, and to summarize the fabrication of BCN thin films by plasma sputtering technique from B4C and BN targets in different gas atmospheres. Pre-set criteria are used to discuss the processing parameters affecting BCN performance which includes the gasses flow ratio and effect of temperature. Moreover, many characterization studies such as mechanical, etching, optical, photoluminescence, XPS, and corrosion studies of the RF sputtered BCN thin films are also covered. We further mentioned the application of BCN thin films to enhance the electrical properties of metal-insulator-metal (MIM) devices according to a previous report of Prakash et al. (Opt. Lett. 41, 4249, 2016).
关键词： Radio frequency sputtering,Gas flow ratio,Boron carbon nitride,Metal-insulator-metal device
更新于2025-09-04 15:30:14
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Dumbbell to Core–Shell Structure Transformation of Ni–Au Nanoparticle Driven by External Stimuli
摘要： Conversion of CO2 gas to CO fuels is one of the most promising solutions for the increasing threat of global warming and energy crisis. The efficient catalyst Ni–Au dumbbell converting CO2 into CO at elevated temperatures has high CO product selectivity; however, the accompanied atomic diffusion and subsequent surface reconstruction affect the catalytic efficiency of chemical reaction. Atomic scale characterization of structural evolution of the catalyst, which is essential to correlate the functional mechanism to active catalyst surfaces, is yet to be studied. Here, in situ transmission electron microscopy experiments and atomistic simulations are performed to characterize the structural evolution of Ni–Au dumbbell nanoparticles under two different external stimuli. In the condition of high temperature and vacuum, the Ni–Au nanostructure reveals a clear shape reconstruction from the initial dumbbell to core–shell-like, which is induced by capillary force to minimize free surface energy of the system. The shape transformation involves two stages of processes, initial fast Au diffusion followed by slow source-controlled diffusion. At ambient temperature, the combination of CO2 and electron flux surprisingly induces analogous structural transformation of Ni–Au nanostructure, where the associated chemical reaction and CO absorption stimulate the Au migration on Ni surface. Such surface reconstruction can be widely present in catalytic reactions in different environmental conditions, and the results herein demonstrate the detailed processes of Ni–Au structure evolution, which provide important insights for understanding the catalyst performance.
关键词： core–shell,in situ TEM,catalyst,Ni–Au,gas cell
更新于2025-09-04 15:30:14
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Encyclopedia of Spectroscopy and Spectrometry || Field Ionization Kinetics in Mass Spectrometry
摘要： The mass spectra of molecules, ionized by electron ionization (EI), field ionization (FI) or photoionization (PI) in the gas phase, usually show many peaks with varying intensities. These peaks result from fragment ions generated by a series of competing and consecutive unimolecular dissociation reactions of the molecular ions provided that the latter have obtained during their formation an amount of energy in excess of the ionization energy of the corresponding molecules. The resulting mass spectrum therefore is determined by the relative rates of these unimolecular dissociation reactions, which in their turn are related to the relative abundances of the fragment ions observed. It will be clear that studying the kinetics of ion dissociation can provide an invaluable insight into the foundation of a mass spectrum.
关键词： Gas-Phase Ion Chemistry,Unimolecular Dissociation,Ion Lifetimes,Mass Spectrometry,Field Ionization Kinetics
更新于2025-09-04 15:30:14
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AIP Conference Proceedings [Author(s) SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems - Santiago, Chile (26–29 September 2017)] - Preliminary tests of an integrated gas turbine-solar particle heating and energy storage system
摘要： Worldwide research efforts are aiming to push the operating temperature limit of CSP systems to improve efficiency and, as a result, the levelized cost of electricity. Furthermore, with higher operating temperatures, a number of new concepts become feasible, the most important of which are supercritical CO2 cycles and air Brayton cycles. Hybrid CSP-fossil fuel systems fall within the air Brayton family of concepts, where the solar field is used to preheat air, while a fossil fuel is burned to bring the air temperature to the firing temperature of a gas-fired Brayton turbine. To make this approach more attractive and environmentally friendly, it is desirable to maximize the solar “contribution” and minimize fuel assistance. This can be done by using novel receivers that increase the air temperature significantly and/or employing a recuperator, where the operating pressure and temperature are lower than conventional Brayton cycles. This paper presents information about an experimental integrated gas turbine-solar particle heating system that uses the hybrid approach. The system is located on the campus of King Saud University in Riyadh, Saudi Arabia and has a peak thermal power of 300 kW. In addition to providing details about the individual components and how they are integrated, the paper explains the start-up procedure, which consists of preheating the system with the heliostat field, followed by additional heating from the turbine itself until the nominal heat exchanger operating temperature is reached, at which point on-sun operation can commence. The study shows that solar preheating requires one to two days to complete, followed by a few hours of heating by the turbine to bring the temperature to about 560°C. Furthermore, with a temperature rise of up to 180°C in the particle heating receiver (and a drop of 10°C in the particle conveyor), the maximum particle temperature will approach 730°C, making the solar contribution significant. As larger scale systems will naturally allow for larger particle drop heights and higher temperature rises in the receiver, it is envisaged that maximum particle tempertures in those systems will approach the firing temperatures of recuperated turbines, making this solution technically, economically, and environmentally worth considering.
关键词： solar preheating,CSP systems,particle heating receiver,hybrid CSP-fossil fuel systems,gas turbine
更新于2025-09-04 15:30:14
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Review on multi gas detector using infrared spectral absorption technology
摘要： To provide some references for researchers engaged in infrared multi gas detection, this study introduced the infrared multi gas detection system thoroughly from infrared light source, infrared detector, optical multiplexing structure, and detection method. Currently, the coherent source represented by quantum cascade laser has replaced the traditional incoherent source like thermal radiant infrared light source and became the dominant light source in infrared multi gas detection. Accordingly, the infrared photodetector is widely used. The optical multiplexing structure based on the “multiplexing thought” is the core of infrared multi gas detection system. It mainly includes the single-source multiplex detection structure and multi-source multiplexing detection structure. Nondispersive infrared spectroscopy, long optical distance spectroscopy, wavelength/frequency modulation spectroscopy, cavity enhancement spectroscopy, and photoacoustic spectroscopy are major detection methods used in the infrared multi gas detection. This has important significance to many fields, such as industrial and agriculture production, environmental monitoring, life science, etc.
关键词： optical multiplexing structure,infrared spectroscopy,infrared detector,Multi gas detection,infrared light source
更新于2025-09-04 15:30:14
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Echo Spectroscopy in Multilevel Quantum-Mechanical Rotors
摘要： We study the dynamics of rotational echoes in gas phase molecular ensembles and their dependence on the delay and intensity of the excitation pulses. We explore the unique dynamics of alignment echoes that arise from the multilevel nature of the molecular rotors and impose severe difficulties in utilizing echo responses for rotational spectroscopy. We show experimentally and theoretically that judicious control of both the delay and intensity of the second pulse enables multilevel “rotational echo spectroscopy.” The proposed methodology paves the way to rotational spectroscopy in high-density gas samples.
关键词： rotational echoes,echo spectroscopy,gas phase molecular ensembles,multilevel quantum-mechanical rotors
更新于2025-09-04 15:30:14