scholarly journals The Determination of Temperatures of Light Sources for the Spectroscopic Analysis from Spectra

1964 ◽  
Vol 13 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Research Group Concerning Spectrosc ◽  
Hiroshi KAWAGUCHI
Tetrahedron ◽  
1991 ◽  
Vol 47 (22) ◽  
pp. 3621-3632 ◽  
Author(s):  
Atsushi Takahashi ◽  
Hiroshi Naganawa ◽  
Daishiro Ikeda ◽  
Yoshiro Okami

2011 ◽  
Vol 7 (S282) ◽  
pp. 203-204
Author(s):  
Paweł Zieliński ◽  
Martin Vaňko ◽  
Ellyn Baines ◽  
Andrzej Niedzielski ◽  
Aleksander Wolszczan

AbstractWe propose to measure the radii of the Penn State - Toruń Planet Search (PTPS) exoplanet host star candidates using the CHARA Array. Stellar radii estimated from spectroscopic analysis are usually inaccurate due to indirect nature of the method and strong evolutionary model dependency. Also, the so-called degeneracy of stellar evolutionary tracks due to convergence of many tracks in the giant branch decreases the precision of such estimates. However, the radius of a star is a critical parameter for the calculation of stellar luminosity and mass, which are often not well known especially for giants. With well determined effective temperature (from spectroscopy) and radius, the luminosity may be calculated precisely. In turn also stellar mass may be estimated much more precisely. Therefore, direct radii measurements increase precision in the determination of planetary candidates masses and the surface temperatures of the planets.


2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2266 ◽  
Author(s):  
Alain Loh ◽  
Marcus Wolff

We report, to our knowledge, the first optical detection scheme for short-chained hydrocarbon isotopologues. The sensor system is based on photoacoustic spectroscopy (PAS). Two continuous wave, thermoelectrically cooled, distributed feedback interband cascade lasers (DFB-ICLs) with emission wavelengths around 3.33 and 3.38 μm, respectively, served as light sources. The investigations comprised the main stable carbon isotopologues of methane (12CH4, 13CH4), ethane (12CH3-12CH3, 13CH3-12CH3, 13CH3-13CH3), and propane (12CH3-12CH2-12CH3, 13CH3-12CH2-12CH3). They were selected because of their importance for numerous applications from climate and planetary research to natural gas exploration. Multiple measurements of single components in nitrogen and synthetic mixtures were conducted at room temperature and atmospheric pressure. Depending on the investigated hydrocarbon isotopologue, detection limits ranging from 0.043 ppmv to 3.4 ppmv were achieved. For a selective concentration determination, multivariate analysis (MVA) was applied. Partial least-squares regression (PLSR) was used to calculate concentrations from the PA spectra. The implementation of MVA has shown that the PA setup in principle works reliably and that the selective concentration determination of short-chained hydrocarbon isotopologues is possible.


2020 ◽  
Vol 59 (1) ◽  
pp. 88-94
Author(s):  
M P Sathianarayanan ◽  
Rina Nayak ◽  
Yogesh Hande

Abstract Hexavalent chromium detection in the presence of high load of colorants is a challenge, and it is an important area of study. Colorants are a class of interfering substance in many spectroscopic analysis and chromatographic separation and detection. In this study, a method has been developed to separate out Cr (VI) and water-soluble dyes by using activated charcoal as an absorption medium. The extraction procedure was optimized with Cr (VI) standard solution for quantification. The efficacy of the extraction procedure for the removal of water-soluble dyes and detection of Cr (VI) was checked with a spike recovery study. Based on the spike recovery study, the method has been validated as per the international validation protocol. The method is simple, cost effective and has a detection limit down up to 3.0 mg/kg. The recovery rate of Cr (VI) in water-soluble dyes like reactive yellow HE 6G, reactive red 218, turquoise blue HGN, reactive navy blue RX and reactive black 5A was found to be more than 90% with a good repeatability and reproducibility.


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