The Experts below are selected from a list of 95625 Experts worldwide ranked by ideXlab platform

Amir Khodabakhsh - One of the best experts on this subject based on the ideXlab platform.

  • time resolved mid infrared dual comb spectroscopy
    Scientific Reports, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this “fingerprint” region. Here we report time-resolved mid-infrared dual-comb spectroscopy, covering ~300 nm bandwidth around 3.3 μm with 6 GHz spectral resolution and 20 μs temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.

  • time resolved mid infrared dual comb spectroscopy
    arXiv: Applied Physics, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this "fingerprint" region. Here we report time-resolved mid-infrared dual-comb spectroscopy for the first time, covering ~300 nm bandwidth around 3.3 {\mu}m with 6 GHz spectral resolution and 20 {\mu}s temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.

Muhammad Ali Abbas - One of the best experts on this subject based on the ideXlab platform.

  • time resolved mid infrared dual comb spectroscopy
    Scientific Reports, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this “fingerprint” region. Here we report time-resolved mid-infrared dual-comb spectroscopy, covering ~300 nm bandwidth around 3.3 μm with 6 GHz spectral resolution and 20 μs temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.

  • time resolved mid infrared dual comb spectroscopy
    arXiv: Applied Physics, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this "fingerprint" region. Here we report time-resolved mid-infrared dual-comb spectroscopy for the first time, covering ~300 nm bandwidth around 3.3 {\mu}m with 6 GHz spectral resolution and 20 {\mu}s temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.

G Nagarajan - One of the best experts on this subject based on the ideXlab platform.

  • effect of injection pressure on performance emission and Combustion characteristics of high linolenic linseed oil methyl ester in a di diesel engine
    Renewable Energy, 2009
    Co-Authors: Sukumar Puhan, R Jegan, K Balasubbramanian, G Nagarajan
    Abstract:

    Due to the increasing demand for fossil fuels and environmental threat, a number of renewable sources of energy have been studied worldwide. In the present investigation a high linolenic linseed oil methyl ester has been investigated in a constant speed, DI diesel engine with varied fuel injection pressures (200, 220 and 240bar). The main objective of this study is to investigate the effect of injection pressures on performance, emissions and Combustion characteristics of the engine. The test results show that the optimum fuel injection pressure is 240bar with linseed methyl ester. At this optimized pressure the thermal efficiency is similar to diesel and a reduction in carbon monoxide, unburned hydrocarbon and smoke emissions with an increase in the oxides of nitrogen was noticed compared to diesel. The Combustion Analysis shows that, the ignition delay is lower at higher injection pressures compared to diesel and the peak pressure is also higher at full load. The Combustion duration was almost same at all the injection pressures. It is concluded that linseed methyl ester at 240bar injection pressure is more efficient than 200 and 220bar, except for nitrogen oxides emission.

  • Combustion Analysis on a di diesel engine with hydrogen in dual fuel mode
    Fuel, 2008
    Co-Authors: N Saravanan, G Nagarajan, G Sanjay, C Dhanasekaran, K M Kalaiselvan
    Abstract:

    Abstract Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms. In this experimental investigation, the Combustion Analysis was done on a direct injection (DI) diesel engine using hydrogen with diesel and hydrogen with diethyl ether (DEE) as ignition source. The hydrogen was injected through intake port and diethyl ether was injected through intake manifold and diesel was injected directly inside the Combustion chamber. Injection timings for hydrogen and DEE were optimized based on the performance, Combustion and emission characteristics of the engine. The optimized timing for the injection of hydrogen was 5° CA before gas exchange top dead center (BGTDC) and 40° CA after gas exchange top dead center (AGTDC) for DEE. From the study it was observed that hydrogen with diesel results in increased brake thermal efficiency by 20% and oxides of nitrogen (NOx) showed an increase of 13% compared to diesel. Hydrogen-DEE operation showed a higher brake thermal efficiency of 30%, with a significant reduction in NOx compared to diesel.

Hua Zhao - One of the best experts on this subject based on the ideXlab platform.

  • High load performance and Combustion Analysis of a four-valve direct injection gasoline engine running in the two-stroke cycle
    Applied Energy, 2015
    Co-Authors: Macklini Dalla Nora, Hua Zhao
    Abstract:

    With the introduction of CO2 emissions legislation or fuel economy standards in Europe and many countries, significant effort is being made to improve spark ignition gasoline engines because of their dominant market share in passenger cars and potential for better fuel economy. Amongst several approaches, the engine downsizing technology has been adopted by the automotive companies as one of the most effective methods to reduce fuel consumption of gasoline engines. However, aggressive engine downsizing is constrained by excessive thermal and mechanical loads as well as knocking Combustion and low speed pre-ignition (also known as super-knock). In order to overcome such difficulties, a gasoline direct injection single cylinder engine was modified to run under the two-stroke cycle by operating the intake and exhaust valves around bottom dead centre (BDC) at every crankshaft revolution. The Combustion products were scavenged by means of a reversed tumble flow of compressed air during the positive valve overlap period at BDC. The engine output was determined by the charging and trapping efficiencies, which were directly influenced by the intake and exhaust valve timings and boost pressures. In this research a valve timing optimisation study was performed using a fully flexible valve train unit, where the intake and exhaust valve timings were advanced and retarded independently at several speeds and loads. A supercharger was used to vary the load by increasing the intake pressure. The effects of valve timing and boost pressure in this two-stroke poppet valve engine were investigated by a detailed Analysis of the gas exchange process and Combustion heat release. Gaseous and smoke emissions were measured and analysed. The results confirmed that the two-stroke cycle operation enabled the indicated mean effective pressure to reach 1.2MPa (equivalent to 2.4MPa in a four-stroke cycle) with an in-cylinder pressure below 7MPa at an engine speed as low as 800rpm. The engine operation was limited by scavenging inefficiencies and short time available for proper air–fuel mixing at high speeds using the current fuel injector. The large amounts of hot residual gas trapped induced controlled auto-ignition Combustion at high speeds, and thus the abrupt heat release limited higher loads.

Frans J M Harren - One of the best experts on this subject based on the ideXlab platform.

  • time resolved mid infrared dual comb spectroscopy
    Scientific Reports, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this “fingerprint” region. Here we report time-resolved mid-infrared dual-comb spectroscopy, covering ~300 nm bandwidth around 3.3 μm with 6 GHz spectral resolution and 20 μs temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.

  • time resolved mid infrared dual comb spectroscopy
    arXiv: Applied Physics, 2019
    Co-Authors: Muhammad Ali Abbas, Qing Pan, Julien Mandon, Simona M Cristescu, Frans J M Harren, Amir Khodabakhsh
    Abstract:

    Dual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this "fingerprint" region. Here we report time-resolved mid-infrared dual-comb spectroscopy for the first time, covering ~300 nm bandwidth around 3.3 {\mu}m with 6 GHz spectral resolution and 20 {\mu}s temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/Combustion Analysis.