Digital, phase-sensitive detection for in situ diode-laser spectroscopy under rapidly changing transmission conditions

2002 ◽  
Vol 75 (2-3) ◽  
pp. 229-236 ◽  
Author(s):  
T. Fernholz ◽  
H. Teichert ◽  
V. Ebert
Keyword(s):  
Diode Laser ◽  
Laser Spectroscopy ◽  
Transmission Conditions ◽  
Sensitive Detection ◽  
Digital Phase ◽  
Diode Laser Spectroscopy ◽  
Phase Sensitive ◽  
Phase Sensitive Detection

scholarly journals CO2 Methanation over Rh/CeO2 Studied with Infrared Modulation Excitation Spectroscopy and Phase Sensitive Detection

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 601
Author(s):  
Felix Hemmingsson ◽  
Andreas Schaefer ◽  
Magnus Skoglundh ◽  
Per-Anders Carlsson
Keyword(s):  
Reaction Pathway ◽  
Sensitive Detection ◽  
Side Reactions ◽  
Co2 Methanation ◽  
Individual Contributions ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation Spectroscopy ◽  
Modulation Excitation

Methane is a well-established fuel molecule whose production from CO 2 through methanation garners increasing interest as an energy storage solution. While often produced with Ni based catalysts, other metals are of interest thanks to higher robustness and activity-selectivity numbers. The Rh/CeO 2 catalyst has shown appreciable properties for CO 2 methanation and its structural dynamics has been studied in situ. However, the reaction pathway is unknown. Here, we present infrared modulation excitation spectroscopy measurements with phase sensitive detection of a Rh/CeO 2 catalyst adsorbate composition during H 2 pulsing (0–2 vol.%) to a constant CO 2 (0.5 vol.%) feed. Various carbonyl (CO) and carbonate (b-CO 3 /p-CO 3 ) ad-species clearly respond to the hydrogen stimulus, making them potential reaction intermediates. The different CO ad-species are likely intermediates for product CO and CH 4 but their individual contributions to the respective formations are not unambiguously ascertained. As for the carbonate dynamics, it might be linked to the reduction/oxidation of the CeO 2 surface upon H 2 pulsing. Formate (HCOO) ad-species are clearly visible but appear to be, if not spectators, linked to slow side reactions possibly also affected by CeO 2 redox processes.

Diode laser spectroscopy of H2O and CO2 in the 1.877-μm region for the in situ monitoring of the Martian atmosphere

2005 ◽  
Vol 82 (1) ◽  
pp. 133-140 ◽  
Author(s):  
T. Le Barbu ◽  
B. Parvitte ◽  
V. Zéninari ◽  
I. Vinogradov ◽  
O. Korablev ◽  
...  
Keyword(s):  
Diode Laser ◽  
Laser Spectroscopy ◽  
Martian Atmosphere ◽  
In Situ Monitoring ◽  
Diode Laser Spectroscopy

In situ, real-time diagnostics of OMVPE using IR-diode laser spectroscopy

1986 ◽  
Vol 77 (1-3) ◽  
pp. 163-171 ◽  
Author(s):  
J.E. Butler ◽  
N. Bottka ◽  
R.S. Sillmon ◽  
D.K. Gaskill
Keyword(s):  
Real Time ◽  
Diode Laser ◽  
Laser Spectroscopy ◽  
Diode Laser Spectroscopy

Application of modulation excitation-phase sensitive detection-DRIFTS for in situ/operando characterization of heterogeneous catalysts

2019 ◽  
Vol 4 (5) ◽  
pp. 862-883 ◽  
Author(s):  
Priya D. Srinivasan ◽  
Bhagyesha S. Patil ◽  
Hongda Zhu ◽  
Juan J. Bravo-Suárez
Keyword(s):  
Fourier Transform ◽  
Heterogeneous Catalysts ◽  
Diffuse Reflectance ◽  
Sensitive Detection ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation ◽  
General Method

A new more general method and guidelines for the implementation of modulation excitation-phase sensitive detection-diffuse reflectance Fourier transform spectroscopy (ME-PSD-DRIFTS).

Application of Digital Phase Sensitive Detection for Electromagnetic Propagation Logging while Drilling

2012 ◽  
Vol 468-471 ◽  
pp. 546-549 ◽  
Author(s):  
Sheng Hu Liu ◽  
Ya Min Xing
Keyword(s):  
Electromagnetic Interference ◽  
High Performance ◽  
Sensitive Detection ◽  
Control Logic ◽  
Electromagnetic Propagation ◽  
Calculating Method ◽  
Digital Phase ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Logging While Drilling

Intense electromagnetic interference while drilling prevents traditional analog phase sensitive detection (APSD) from correctly acquiring electromagnetic wave signal of logging while drilling (LWD). A digital phase sensitive detection (DPSD) utilizes high-performance floating-point DSP and FPGA to separately process real part and imaginary part of the acquired logging signal, changes traditional calculating method, improves processing speed and calculating precision. The programmable technique used can fully utilize logging information, simplify control logic, improve precision of timing control and measuring precision. Discussed are the principle, characteristics, implement of circuit and analysis of experimental data. Testing result shows that the DPSD may utilize logging information effectively and optimize the LWD system.

Implementation of Digital Phase-Sensitive Detection in Wavelength Modulation Spectroscopy Measurement System

2013 ◽  
Vol 40 (11) ◽  
pp. 1115001
Author(s):  
李晗 Li Han ◽  
刘建国 Liu Jianguo ◽  
阚瑞峰 Kan Ruifeng ◽  
姚路 Yao Lu ◽  
许振宇 Xu Zhenyu ◽  
...  
Keyword(s):  
Measurement System ◽  
Wavelength Modulation Spectroscopy ◽  
Sensitive Detection ◽  
Wavelength Modulation ◽  
Modulation Spectroscopy ◽  
Spectroscopy Measurement ◽  
Digital Phase ◽  
Phase Sensitive ◽  
Phase Sensitive Detection

Bioelectrical Impedance Measurement Way Based on an Improved DPSD Algorithm

2012 ◽  
Vol 182-183 ◽  
pp. 1694-1697
Author(s):  
Jie Tao Diao ◽  
Qi You Xie ◽  
Miao Li ◽  
Wen Li Liu ◽  
Zhao Lin Sun
Keyword(s):  
Impedance Measurement ◽  
Bioelectrical Impedance ◽  
Sensitive Detection ◽  
Improved Method ◽  
Digital Phase ◽  
Phase Sensitive ◽  
Phase Sensitive Detection

In Bioelectrical impedance measurement, the impedance accuracy is a very important parameter. With the analysis of general Digital Phase Sensitive Detection (DPSD) algorithm and its error, this paper presents an improved DPSD algorithm. In this method, it firstly decomposes the orthogonal signals which have passed through the networks, and then sums (minus) the relevant signals to get the parameters amplitude and phase. By this way, it can avoid errors caused by filtering operation in general DPSD algorithm. At last, the paper gives a simulation which can be hardware-based achieved. The result proves the effectiveness and feasibility of this improved method.

Design, modelling, and application of a low void-volume in situ diffuse reflectance spectroscopic reaction cell for transient catalytic studies

2019 ◽  
Vol 4 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Bhagyesha S. Patil ◽  
Priya D. Srinivasan ◽  
Ed Atchison ◽  
Hongda Zhu ◽  
Juan J. Bravo-Suárez
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Void Volume ◽  
Sensitive Detection ◽  
Reaction Cell ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation

A new low void-volume in situ reaction cell enables application of modulation excitation-phase sensitive detection-diffuse reflectance Fourier transform spectroscopy (ME-PSD-DRIFTS).

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