Morphology Dependent Resonances in Raman Spectra of Optically Levitated Microparticles: Determination of Radius and Evaporation Rate of Single Glycerol/Water Droplets by means of Internal Mode Assignment

1993 ◽  
Vol 97 (8) ◽  
pp. 1007-1011 ◽  
Author(s):  
K. Schaschek ◽  
J. Popp ◽  
W. Kiefer
Keyword(s):  
Raman Spectra ◽  
Evaporation Rate ◽  
Internal Mode ◽  
Water Droplets ◽  
Glycerol Water ◽  
Mode Assignment ◽  
Morphology Dependent Resonances

scholarly journals Possibility of Human Gender Recognition Using Raman Spectra of Teeth

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3983
Author(s):  
Ozren Gamulin ◽  
Marko Škrabić ◽  
Kristina Serec ◽  
Matej Par ◽  
Marija Baković ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Principal Component ◽  
Support Vector ◽  
Gender Recognition ◽  
Proof Of Concept ◽  
Male And Female ◽  
Tooth Type ◽  
Tooth Apex ◽  
The Difference

Gender determination of the human remains can be very challenging, especially in the case of incomplete ones. Herein, we report a proof-of-concept experiment where the possibility of gender recognition using Raman spectroscopy of teeth is investigated. Raman spectra were recorded from male and female molars and premolars on two distinct sites, tooth apex and anatomical neck. Recorded spectra were sorted into suitable datasets and initially analyzed with principal component analysis, which showed a distinction between spectra of male and female teeth. Then, reduced datasets with scores of the first 20 principal components were formed and two classification algorithms, support vector machine and artificial neural networks, were applied to form classification models for gender recognition. The obtained results showed that gender recognition with Raman spectra of teeth is possible but strongly depends both on the tooth type and spectrum recording site. The difference in classification accuracy between different tooth types and recording sites are discussed in terms of the molecular structure difference caused by the influence of masticatory loading or gender-dependent life events.

Determination of the size and composition of multicomponent ethanol/water droplets by cavity-enhanced Raman scattering

2003 ◽  
Vol 380 (5-6) ◽  
pp. 665-672 ◽  
Author(s):  
Rebecca J. Hopkins ◽  
Rachel Symes ◽  
Robert M. Sayer ◽  
Jonathan P. Reid
Keyword(s):  
Raman Scattering ◽  
Water Droplets ◽  
Enhanced Raman Scattering

scholarly journals Does Non-ionizing Radiant Energy Affect Determination of the Evaporation Rate by the Gradient Method?

1991 ◽  
Vol 96 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Sveinn Kjartansson ◽  
Karen Hammarlund ◽  
Per Åke Öberg ◽  
Gunnar Sedin
Keyword(s):  
Gradient Method ◽  
Evaporation Rate ◽  
Radiant Energy

Determination of water speciation in hydrous haplogranitic glasses with partial Raman spectra

2020 ◽  
Vol 553 ◽  
pp. 119793
Author(s):  
Christoph Helo ◽  
Jonathan M. Castro ◽  
Kai-Uwe Hess ◽  
Donald B. Dingwell
Keyword(s):  
Raman Spectra ◽  
Water Speciation

Effects of Wet Compression on the Flow Behavior of a Centrifugal Compressor: A CFD Analysis

2014 ◽  
Author(s):  
Anish Surendran ◽  
Heuy Dong Kim
Keyword(s):  
Flow Rate ◽  
Water Droplet ◽  
Evaporation Rate ◽  
Pressure Ratio ◽  
Phase Flow ◽  
Water Droplets ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression ◽  
Injection Ratio

Wet compression has been emerging as a prominent method for augmenting net power output from land based gas turbine engine. It is proven more effective than the conventional inlet cooling methods. In this method, fine water droplets are injected just upstream of the compressor impeller. These water droplets absorb the latent heat of evaporation during the compression process of gas-water droplet two-phase flow, consequently reducing the temperature rise. Many gas turbine engineers have performed the feasibility and usefulness studies on this wet compression, but physical understanding on the wet compression process is highly lacking, and related compression flow mechanism remains ambiguous. In the present study, a computational fluid dynamics method has been applied to investigate the wet compression effects on a low speed centrifugal compressor. A Langrangian particle tracking method was employed to simulate the air-water droplet two-phase flow. The power saving achieved with different injection ratio of water droplets has been calculated and it is found that significant saving can be obtained with a water droplet injection ratio of above 3%. The vapor mass fraction varies linearly along the streamwise direction, making the assumption for a constant evaporation rate is valid. With the increase in the injection ratio the polytropic index for compression is coming down. The diffuser pressure recovery has been improved significantly with the wet compression; while the total pressure ratio across the impeller does not improve much. Contrary to the expectation, the evaporation rate is found to be coming down with the increase in the compressor mass flow rate. It is observed that the operating point, at which the peak pressure ratio occurs, shift towards higher mass flow rate during wet compression due to the local recirculation region within the vaneless space between the impeller and diffuser.

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