Absolute Raman intensity measurements and determination of the vibrational second hyperpolarizability of adamantyl endcapped polyynes

2012 ◽  
Vol 43 (9) ◽  
pp. 1293-1298 ◽  
Author(s):  
A. Lucotti ◽  
M. Tommasini ◽  
D. Fazzi ◽  
M. Del Zoppo ◽  
W. A. Chalifoux ◽  
...  
Keyword(s):  
Raman Intensity ◽  
Second Hyperpolarizability ◽  
Intensity Measurements

Composition of Mixtures of Natural Gas Components Determined by Raman Spectrometry

1980 ◽  
Vol 34 (4) ◽  
pp. 411-414 ◽  
Author(s):  
Dwain E. Diller ◽  
Ren Fang Chang
Keyword(s):  
Natural Gas ◽  
Mole Fraction ◽  
Gas Mixtures ◽  
Spectrometric Method ◽  
Gas Mixture ◽  
Raman Intensity ◽  
Raman Spectrometry ◽  
Intensity Measurements ◽  
Hydrocarbon Gas ◽  
Related Line

The feasibility of using Raman spectrometry for determining the composition of mixtures of natural gas components was examined. Raman intensity measurements were carried out on eight, gravimetrically prepared, binary gas mixtures containing methane, nitrogen, and isobutane at ambient temperature and at pressures to 0.8 MPa. The repeatability of the molar intensity ratio, ( I2/ y2)/( I1/ y1), where y1 is the concentration of component 1 in the mixture, and I1 is the intensity of the related line in the mixture spectrum, was examined. The compositions of two gravimetrically prepared methane-nitrogen-isobutane gas mixtures were determined spectrometrically with an estimated precision of about 0.001 in the mole fraction. Typical differences from the gravimetric concentrations were less than 0.002 in the mole fraction. The Raman spectrum of a gravimetrically prepared, eight component, hydrocarbon gas mixture was obtained to show that the Raman spectrometric method has potential for being applicable to natural gas type mixtures.

scholarly journals Quantitative Ausmessung des Brom-Affinitätskontinuums und Bestimmung der Detachment-und Attachment-Querschnitte

1970 ◽  
Vol 25 (11) ◽  
pp. 1617-1626 ◽  
Author(s):  
H. Frank ◽  
M. Neiger ◽  
H.-P. Popp
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Electron Affinity ◽  
Elastic Cross Section ◽  
Electron Atom ◽  
Intensity Measurements ◽  
Long Wave ◽  
The Mean ◽  
Intense Electron

Abstract A wall stabilized low-current cylindric arc was used to produce the radiation of the negative Bromine-ions. The radiation consists of an affinity-continuum with a long-wave threshold of 3682 Å, yielding an electron affinity for Bromine of 3.366 eV, and of an intense electron-atom Bremsstrahlung in the visible. Intensity measurements of the continua allow the determination of the photo-detachment-and attachment-cross-sections of Bromine and also the determination of the mean elastic cross-section of electrons against Bromine atoms.

Nichtgleichgewichtscffekte im Argonkaskadenbogen im Druckbereich von 0,2 atm bis 5,0 atm / Non-LTE Effects in an Argon Cascade Arc in the Pressure Range from 0.2 atm to 5.0 atm

1973 ◽  
Vol 28 (9) ◽  
pp. 1459-1467 ◽  
Author(s):  
D. Garz
Keyword(s):  
Particle Temperature ◽  
Energy Levels ◽  
Heavy Particle ◽  
Electrical Current ◽  
Mean Free Path ◽  
Electrical Field Strength ◽  
Intensity Measurements ◽  
Plasma State ◽  
Significant Intensity

An analysis of the plasma state was performed by determination of the electron temperature and the distribution temperature from end -on intensity measurements in the arc axis and by determination of the heavy particle temperature from measurements of the electrical field strength. The electrical current of the arc was varied between 1.5 amp and 60 amp and the argon pressure was varied from 0.2 atm to 5.0 atm. It turned out that not the electron density but the mean free path of the electrons is the essential parameter for the adjustment of LTE. Moreover radial end-on intensity measurements of Ar-I lines with different upper energy levels revealed significant intensity anomalies spreading from the axis of the arc to the walls. These effects could be explained assuming that a diffusion of Ar atoms, which are excited to 4s-levels, takes place out of the arc axis. The diffusion equation and its solution led to a satisfying explanation of the observed radial non-LTE effects.

Sign in / Sign up

Export Citation Format

Share Document