The Gigahertz and Terahertz spectrum of monodeutero-oxirane (c-C2H3DO)

2019 ◽  
Vol 21 (7) ◽  
pp. 3669-3675 ◽  
Author(s):  
Sieghard Albert ◽  
Ziqiu Chen ◽  
Karen Keppler ◽  
Philippe Lerch ◽  
Martin Quack ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Synchrotron Radiation ◽  
Light Source ◽  
Fourier Transform Infrared ◽  
Rotational Spectrum ◽  
Terahertz Spectrum ◽  
Swiss Light Source ◽  
Ftir Spectrometer ◽  
Spectrometer System

The rotational spectrum of monodeutero-oxirane was analysed as measured using the Zurich Gigahertz (GHz) spectrometer and our highest resolution Fourier Transform Infrared (FTIR) spectrometer system coupled to synchrotron radiation at the Swiss Light Source (SLS).

Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer Under Modulated–Pulsed Light Source Excitation

2020 ◽  
Vol 74 (7) ◽  
pp. 799-807 ◽  
Author(s):  
Ahmed M. Othman ◽  
Hussein E. Kotb ◽  
Yasser M. Sabry ◽  
Diaa Khalil
Keyword(s):  
Fourier Transform ◽  
Mechanical System ◽  
Light Source ◽  
Repetition Rate ◽  
Fourier Transform Infrared ◽  
Micro Electro Mechanical System ◽  
Pulsed Light ◽  
Ft Ir ◽  
Spectrometer System ◽  
Source Excitation

Miniaturized Fourier transform infrared (FT-IR) spectrometers suffer from limited optical throughput due to their tiny aperture size. Therefore, coherent wideband sources with high brightness can provide an advantage over the wideband thermal radiation sources. However, the former ones are available based on pulsed operation. In this work, we present and study a miniaturized FT-IR spectrometer with pulsed light sources including chopped thermal source, semiconductor optical amplifier, Q-switched and femtosecond mode-locked laser sources. A system model for the FT-IR spectrometer system under a modulated input light source is presented. The model accounts for the relatively high scanning speed of the micro-electro-mechanical system (MEMS) interferometer. The signal-to-noise ratio of the spectrometer, due to the light source modulation, is calculated at different values of modulation repetition rate ranging from 20 Hz to 2 MHz, and duty cycle values ranging from 1% to 50%. An analytical expression for the worst-case repetition rate for the spectrometer system is derived. The model results are verified by experimental measurements showing good agreement with the theoretical expectations. Spectroscopic measurements for CO2 gas with pressure ranging from 300 mbar to 700 mbar are also performed using a high-repetition rate source, and the measured spectra agree with the simulation results demonstrating the utility of the spectrometer.

scholarly journals Kinetics of 1- and 2-methylallyl + O2 reaction, investigated by photoionisation using synchrotron radiation

2021 ◽  
Author(s):  
Domenik Schleier ◽  
Engelbert Reusch ◽  
Marius Gerlach ◽  
Tobias Preitschopf ◽  
Deb Pratim Mukhopadhyay ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Reaction Kinetics ◽  
Molecular Oxygen ◽  
Light Source ◽  
Storage Ring ◽  
Vacuum Ultraviolet ◽  
Flow Tube ◽  
Tube Reactor ◽  
Swiss Light Source ◽  
Kinetics Of

The reaction kinetics of the isomers of the methylallyl radical with molecular oxygen has been studied in a flow tube reactor at the vacuum ultraviolet (VUV) beamline of the Swiss Light Source storage ring.

Analysis of Captan on Nitrile Glove Surfaces Using a Portable Attenuated Total Reflection Fourier Transform Infrared Spectrometer

2005 ◽  
Vol 59 (6) ◽  
pp. 724-731 ◽  
Author(s):  
R. N. Phalen ◽  
Shane S. Que Hee
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Surface Films ◽  
Airflow Rate ◽  
Infrared Spectrometer ◽  
Ftir Spectrometer ◽  
Selection Of ◽  
Solvent Volume

This study developed a method to produce uniform captan surface films on a disposable nitrile glove for quantitation with a portable attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer. A permeation test was performed using aqueous captan formulation. Uniform captan surface films were produced using solvent casting with 2-propanol and a 25 mm filter holder connected to a vacuum manifold to control solvent evaporation. The coefficient of variation of the reflectance at 1735 ± 5 cm−1 was minimized by selection of the optimum solvent volume, airflow rate, and evaporation time. At room temperature, the lower to upper quantifiable limits were 0.31–20.7 μg/cm2 ( r = 0.9967; p ≤ 0.05) for the outer glove surface and 0.55–17.5 μg/cm2 ( r = 0.9409; p ≤ 0.05) for the inner surface. Relative humidity and temperature did not affect the uncoated gloves at the wavelength of captan analysis. Glove screening using ATR-FTIR was necessary as a control for between-glove variation. Captan permeation, after 8 hours exposure to an aqueous concentration of 217 mg/mL of Captan 50-WP, was detected at 0.8 ± 0.3 μg/cm2 on the inner glove surface. ATR-FTIR can detect captan permeation and can determine the protectiveness of this glove in the field.

scholarly journals First ground-based Fourier transform infrared (FTIR) spectrometer observations of HFC-23 at Rikubetsu, Japan, and Syowa Station, Antarctica

2021 ◽  
Vol 14 (9) ◽  
pp. 5955-5976
Author(s):  
Masanori Takeda ◽  
Hideaki Nakajima ◽  
Isao Murata ◽  
Tomoo Nagahama ◽  
Isamu Morino ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
In Situ Measurements ◽  
Atmospheric Composition ◽  
Syowa Station ◽  
Spectroscopic Parameters ◽  
Dry Air ◽  
Systematic Uncertainties ◽  
Ftir Spectrometer

Abstract. We have developed a procedure for retrieving atmospheric abundances of HFC-23 (CHF3) with a ground-based Fourier transform infrared (FTIR) spectrometer and analyzed the spectra observed at Rikubetsu, Japan (43.5∘ N, 143.8∘ E), and at Syowa Station, Antarctica (69.0∘ S, 39.6∘ E). The FTIR retrievals were carried out with the SFIT4 retrieval program, and the two spectral windows of 1138.5–1148.0 cm−1 and 1154.0–1160.0 cm−1 in the overlapping ν2 and ν5 vibrational–rotational transition bands of HFC-23 were used to avoid strong H2O absorption features. We considered O3, N2O, CH4, H2O, HDO, CFC-12 (CCl2F2), HCFC-22 (CHClF2), peroxyacetyl nitrate (PAN) (CH3C(O)OONO2), HCFC-141b (CH3CCl2F), and HCFC-142b (CH3CClF2) to be interfering species. Vertical profiles of H2O, HDO, and CH4 are preliminarily retrieved with other independent spectral windows because these profiles may induce large uncertainties in the HFC-23 retrieval. Each HFC-23 retrieval has only one piece of vertical information with sensitivity to HFC-23 in the troposphere and the lower stratosphere. Retrieval errors mainly arise from the systematic uncertainties of the spectroscopic parameters used to obtain HFC-23, H2O, HDO, and CH4 abundances. For comparison between FTIR-retrieved HFC-23 total columns and surface dry-air mole fractions provided by AGAGE (Advanced Global Atmospheric Gases Experiment), FTIR-retrieved HFC-23 dry-air column-averaged mole fractions (XHFC-23) were calculated. The FTIR-retrieved XHFC-23 values at Rikubetsu and Syowa Station have negative biases of −15 % to −20 % and −25 % compared to the AGAGE datasets, respectively. These negative biases might mainly come from systematic uncertainties of HFC-23 spectroscopic parameters. The trend of the FTIR-retrieved XHFC-23 data at Rikubetsu was derived for December to February (DJF) observations, which are considered to represent the background values when an air mass reaching Rikubetsu has the least influence by transport of HFC-23 emissions from nearby countries. The DJF trend of Rikubetsu over the 1997–2009 period is 0.810 ± 0.093 ppt yr−1 (ppt: parts per trillion), which is in good agreement with the trend derived from the annual global mean datasets of the AGAGE 12-box model for the same period (0.820 ± 0.013 ppt yr−1). The DJF trend of Rikubetsu over the 2008–2019 period is 0.928 ± 0.108 ppt yr−1, which is consistent with the trend in the AGAGE in situ measurements at Trinidad Head (41.1∘ N, 124.2∘ W) for the same period (0.994 ± 0.001 ppt yr−1). The trend of the FTIR-retrieved XHFC-23 data at Syowa Station over the 2007–2016 period is 0.819 ± 0.071 ppt yr−1, which is consistent with that derived from the AGAGE in situ measurements at Cape Grim (40.7∘ S, 144.7∘ E) for the same period (0.874 ± 0.002 ppt yr−1). Although there are systematic biases in the FTIR-retrieved XHFC-23 at both sites, these results indicate that ground-based FTIR observations have the capability to monitor the long-term trend of atmospheric HFC-23. If this FTIR measurement technique were extended to other Network for the Detection of Atmospheric Composition Change (NDACC) ground-based FTIR sites around world, the measurements reported from these sites would complement the global AGAGE observations by filling spatial and temporal gaps and may lead to improved insights about changes in regional and global emissions of HFC-23 and its role in global warming.

scholarly journals Kesetimbangan Adsorpsi Zat Warna Methyl Violet Oleh Karbon Aktif Berbasis Limbah Daun Nanas (Ananas comosus L)

METANA ◽  
2018 ◽  
Vol 14 (2) ◽  
pp. 31
Author(s):  
Lanjar Lanjar ◽  
Fatma Indah Riayanti ◽  
Widi Astuti
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Surface Area ◽  
Methyl Violet ◽  
Fourier Transform Infrared ◽  
Ananas Comosus ◽  
Ftir Spectrometer ◽  
Model Isotherm ◽  
Scanning Electron

Industri tekstil semakin berkembang seiring dengan pertumbuhan penduduk di Indonesia. Selain memberikan manfaat, industri tekstil  memberikan dampak negatif bagi lingkungan akibat penggunaan zat warna sintetis, salah satunya yaitu methyl violet. Apabila limbah tersebut dibuang ke perairan akan menyebabkan rusaknya ekologi lingkungan dan ancaman bagi kesehatan manusia, karena sebagian besar zat warna bersifat sukar terurai (non-bidegradable) dan karsinogenik (Brono, 2010). Salah satu metode yang terbukti efektif untuk menghilangkan zat warna adalah adsorpsi menggunakan karbon aktif. Pada penelitian ini karbon aktif dibuat dari limbah daun nanas dengan aktivator ZnCl2 dan pemanasan gelombang mikro. Selanjutnya, karbon aktif tersebut dikarakteriasi morfologi permukaan menggunakan Scanning Electron Microscopy (SEM), luas permukaan menggunakan Surface Area Analyzer, dan analisis gugus fungsi menggunakan Fourier Transform Infrared (FTIR) spectrometer, dan digunakan untuk menjerap methyl violet di larutan. Hasil penelitian menunjukkan bahwa karbon aktif dari limbah daun nanas yang teraktivasi ZnCl2 menghasilkan pori yang lebih besar dibandingkan dengan karbon tanpa aktivasi serta memiliki gugus fungsi yang dapat menjerap methyl violet. Kondisi optimum untuk adsorpsi adalah pH 5, waktu kontak 90 menit, dan konsentrasi awal 500 mg/L. Model kesetimbangan yang sesuai yaitu menggunakan model isotherm freundlich.

Testing and development of a mobile Fourier transform infrared spectrometer system for the analysis of atmospheric pollutants

1992 ◽  
Author(s):  
Mark R. Witkowski ◽  
Charles T. Chaffin, Jr. ◽  
Timothy L. Marshall ◽  
Martin L. Spartz ◽  
Jonathan H. Fateley ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Atmospheric Pollutants ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer ◽  
Spectrometer System

THE USE OF A TRANSPORTABLE FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETER FOR THE DIRECT MEASUREMENT OF SOLVENTS IN BREATH AND AMBIENT AIR—I: METHANOL

AIHAJ ◽  
1992 ◽  
Vol 53 (4) ◽  
pp. 221-227 ◽  
Author(s):  
Alfred Franzblau ◽  
Steven P. Levine ◽  
Lou Ann Burgess ◽  
Qing-shan Qu ◽  
Richard M. Schreck ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Direct Measurement ◽  
Fourier Transform Infrared ◽  
Ambient Air ◽  
Ftir Spectrometer
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