scholarly journals Direct Comb Vernier Spectroscopy for Fractional Isotopic Ratio Determinations

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5883
Author(s):  
Mario Siciliani de Cumis ◽  
Roberto Eramo ◽  
Jie Jiang ◽  
Martin E. Fermann ◽  
Pablo Cancio Pastor
Keyword(s):  
Frequency Comb ◽  
Isotopic Ratio ◽  
Global Climate ◽  
Composition Analysis ◽  
Spectroscopic Techniques ◽  
Spectral Content ◽  
Co2 Gas ◽  
Greenhouse Gasses ◽  
Fitting Procedure ◽  
Fabry Perot

Accurate isotopic composition analysis of the greenhouse-gasses emitted in the atmosphere is an important step to mitigate global climate warnings. Optical frequency comb–based spectroscopic techniques have shown ideal performance to accomplish the simultaneous monitoring of the different isotope substituted species of such gases. The capabilities of one such technique, namely, direct comb Vernier spectroscopy, to determine the fractional isotopic ratio composition are discussed. This technique combines interferometric filtering of the comb source in a Fabry–Perot that contains the sample gas, with a high resolution dispersion spectrometer to resolve the spectral content of each interacting frequency inside of the Fabry–Perot. Following this methodology, simultaneous spectra of ro-vibrational transitions of 12C16O2 and 13C16O2 molecules are recorded and analyzed with an accurate fitting procedure. Fractional isotopic ratio 13C/12C at 3% of precision is measured for a sample of CO2 gas, showing the potentialities of the technique for all isotopic-related applications of this important pollutant.

scholarly journals Evidence for frequency comb emission from a Fabry-Pérot terahertz quantum-cascade laser

2014 ◽  
Vol 22 (25) ◽  
pp. 30410 ◽  
Author(s):  
M. Wienold ◽  
B. Röben ◽  
L. Schrottke ◽  
H. T. Grahn
Keyword(s):  
Quantum Cascade Laser ◽  
Frequency Comb ◽  
Quantum Cascade ◽  
Fabry Perot

A Wide Spaced Femtosecond Ti:Sapphire Frequency Comb at 15 GHz by a Fabry—Pérot Filter Cavity

2013 ◽  
Vol 30 (10) ◽  
pp. 104203 ◽  
Author(s):  
Lei Hou ◽  
Hai-Nian Han ◽  
Jin-Wei Zhang ◽  
De-Hua Li ◽  
Zhi-Yi Wei
Keyword(s):  
Frequency Comb ◽  
Fabry Perot

scholarly journals Natural variability and anthropogenic effects in a Central Mediterranean core

2012 ◽  
Vol 8 (2) ◽  
pp. 831-839 ◽  
Author(s):  
S. Alessio ◽  
G. Vivaldo ◽  
C. Taricco ◽  
M. Ghil
Keyword(s):  
Isotopic Ratio ◽  
Forecast Error ◽  
Singular Spectrum Analysis ◽  
Low Frequency ◽  
Natural Variability ◽  
Central Mediterranean ◽  
Spectral Content ◽  
Frequency Components ◽  
Oxygen Isotopic ◽  
Complete Series

Abstract. We evaluate the contribution of natural variability to the modern decrease in foraminiferal δ18O by relying on a 2200-yr-long, high-resolution record of oxygen isotopic ratio from a Central Mediterranean sediment core. Pre-industrial values are used to train and test two sets of algorithms that are able to forecast the natural variability in δ18O over the last 150 yr. These algorithms are based on autoregressive models and neural networks, respectively; they are applied separately to each of the δ18O series' significant variability components, rather than to the complete series. The separate components are extracted by singular-spectrum analysis and have narrow-band spectral content, which reduces the forecast error. By comparing the sum of the predicted low-frequency components to its actual values during the Industrial Era, we deduce that the natural contribution to these components of the modern δ18O variation decreased gradually, until it reached roughly 40%, as early as the end of the 1970s.

Optical Fiber Fabry–Perot Interferometric CO2 Gas Sensor Using Guanidine Derivative Polymer Functionalized Layer

2018 ◽  
Vol 18 (5) ◽  
pp. 1924-1929 ◽  
Author(s):  
Wenwen Ma ◽  
Jiaxian Xing ◽  
Ruohui Wang ◽  
Qiangzhou Rong ◽  
Wenlu Zhang ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Gas Sensor ◽  
Co2 Gas ◽  
Guanidine Derivative ◽  
Co2 Gas Sensor ◽  
Fabry Perot

Isotopic ratio correlation for the isotopic composition analysis of plutonium in Am–Pu mixed samples having High americium content

2013 ◽  
Vol 78 ◽  
pp. 139-144 ◽  
Author(s):  
Sabyasachi Patra ◽  
Chhavi Agarwal ◽  
Sanhita Chaudhury ◽  
T. Newton Nathaniel ◽  
M. Gathibandhe ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Isotopic Ratio ◽  
Composition Analysis ◽  
Ratio Correlation ◽  
Mixed Samples

scholarly journals Tridimensional Spectroscopic Techniques: Conference Summary

1995 ◽  
Vol 149 ◽  
pp. 369-381 ◽  
Author(s):  
J. Bland-Hawthorn
Keyword(s):  
Fourier Transform ◽  
Near Infrared ◽  
Three Dimensional ◽  
Spectroscopic Techniques ◽  
Conference Summary ◽  
Wide Range ◽  
Fabry Perot ◽  
Scientific Results ◽  
General Thrust

Over the last four days, we have enjoyed a wide range of talks on developments in three dimensional spectroscopic techniques. The conference organizing committee are to be congratulated for the artful manner in which instrumental presentations were interleaved with talks on the scientific results from these instruments. The general thrust of most talks was to advance the versatility of traditional instruments either through the Jacquinot (throughput) advantage or through the multiplex advantage, or both. A number of groups have attempted to utilize the full aperture of scanning Fabry-Perot and Fourier Transform interferometers. Arguably, Fabry-Perot interferometers have a wider application at present, although imaging Fourier Transform devices appear to have finally arrived, at least in the near infrared.

Influence of environmental conditions, population density, and prey type on the lipid content in Baltic herring (Clupea harengus membras) from the northern Baltic Sea

2019 ◽  
Vol 76 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Marjut Rajasilta ◽  
Jari Hänninen ◽  
Lea Laaksonen ◽  
Päivi Laine ◽  
Jukka-Pekka Suomela ◽  
...  
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Lipid Content ◽  
Sea Water ◽  
Energy Content ◽  
Global Climate ◽  
Clupea Harengus ◽  
Composition Analysis ◽  
Baltic Herring ◽  
The Baltic

Global climate change can affect the energy content of fish by altering their lipid physiology and consumption. We investigated the effects of different environmental stressors on the lipid content of the Baltic herring (Clupea harengus membras) from spawning ground samples that were collected annually in the northern Baltic Sea. During 1987–2014, the average lipid content of herring muscle decreased from 5%–6% (wet mass) to 1.5% (wet mass). Generalized linear mixed models indicated that sea water salinity and the size of the herring stock explained best the declining trend of lipid content. We estimated that the amount of the lipid storage incorporated in the spawning stock decreased by approximately 45% during the study, with respective energy content decreases. Fatty acid composition analysis revealed that herring lipids contained a high proportion of EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3), which likely originated from its main summertime prey, Limnocalanus macrurus. The results illustrate various climate change-induced processes leading to changes in the lipid content of the Baltic herring and, consequently, to changes in the energy flows of the northern Baltic ecosystem.

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