scholarly journals Rotational spectroscopy of singly 13C substituted isotopomers of propyne and determination of a semi-empirical equilibrium structure

2020 ◽  
Vol 1207 ◽  
pp. 127769
Author(s):  
Holger S.P. Müller ◽  
Sven Thorwirth ◽  
Frank Lewen
2021 ◽  
Vol 154 (24) ◽  
pp. 244310
Author(s):  
Vanessa L. Orr ◽  
Yotaro Ichikawa ◽  
Aatmik R. Patel ◽  
Samuel M. Kougias ◽  
Kaori Kobayashi ◽  
...  

2019 ◽  
Vol 621 ◽  
pp. A143 ◽  
Author(s):  
Holger S. P. Müller ◽  
Atsuko Maeda ◽  
Sven Thorwirth ◽  
Frank Lewen ◽  
Stephan Schlemmer ◽  
...  

Context. Thioformaldehyde is an abundant molecule in various regions of the interstellar medium. However, available laboratory data limit the accuracies of calculated transition frequencies in the submillimeter region, in particular for minor isotopic species. Aims. We aim to determine spectroscopic parameters of isotopologs of H2CS that are accurate enough for predictions well into the submillimeter region. Methods. We investigated the laboratory rotational spectra of numerous isotopic species in natural isotopic composition almost continuously between 110 and 377 GHz. Individual lines were studied for most species in two frequency regions between 566 and 930 GHz. Further data were obtained for the three most abundant species in the 1290−1390 GHz region. Results. New or improved spectroscopic parameters were determined for seven isotopic species. Quantum-chemical calculations were carried out to evaluate the differences between ground state and equilibrium rotational parameters to derive semi-empirical equilibrium structural parameters. Conclusions. The spectroscopic parameters are accurate enough for predictions well above 1 THz with the exception of H213C34S where the predictions should be reliable to around 700 GHz.


Author(s):  
H. S. P. Müller ◽  
A. Brahmi M. ◽  
J.-C. Guillemin ◽  
F. Lewen ◽  
S. Schlemmer

1992 ◽  
Vol 46 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Zhong Yuan Zhu ◽  
M. Cecilia Yappert

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.


1981 ◽  
Vol 103 (2) ◽  
pp. 265-270 ◽  
Author(s):  
R. Kotwal ◽  
W. Tabakoff

With increasing interest in the burning of coal in industrial gas turbines, there is also concern for the precise determination of the erosive effects on the turbine components. Series of experiments were conducted to determine the effects of fly ash constituents, particle size, particle velocity, angle of attack and target temperature on the erosion of iron and nickel base alloys. Based on the experimental results, a semi-empirical equation has been obtained for the prediction of the erosion losses. This equation provides a new technique for predicting the metal erosion due to the fly ash produced by the conventional burning of coal.


1989 ◽  
Vol 134 (1) ◽  
pp. 7-18 ◽  
Author(s):  
B. Bussery ◽  
M.E. Rosenkrantz ◽  
D.D. Konowalow ◽  
M. Aubert-frécon

Sign in / Sign up

Export Citation Format

Share Document