Efficient “On-the-Fly” calculation of Raman Spectra fromAb-Initiomolecular dynamics: Application to hydrophobic/hydrophilic solutes in bulk water

2015 ◽  
Vol 36 (29) ◽  
pp. 2188-2192 ◽  
Author(s):  
Pouya Partovi-Azar ◽  
Thomas D. Kühne
Keyword(s):  
Raman Spectra ◽  
Bulk Water ◽  
Hydrophilic Solutes

STEM measurement of subcellular water distributions

1993 ◽  
Vol 51 ◽  
pp. 568-569
Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews
Keyword(s):  
Water Content ◽  
Internal Standard ◽  
Dry Weight ◽  
Dry Mass ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Bulk Water ◽  
Inelastic Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.

Single Crystal Raman Spectra of the Phase Transition in KTCNQ

1982 ◽  
Vol 85 (1) ◽  
pp. 297-303 ◽  
Author(s):  
A. D. Bandrauk ◽  
K. D. Truong ◽  
S. Jandl
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Raman Spectra

Bulk water treatment unit performance: For the cameras or the community?

Waterlines ◽  
2012 ◽  
Vol 31 (1-2) ◽  
pp. 53-66 ◽  
Author(s):  
Richard Luff ◽  
Caetano Dorea
Keyword(s):  
Water Treatment ◽  
Bulk Water ◽  
Treatment Unit ◽  
Unit Performance

What are the ranges and basis of auxeticity in the phases of cellulose microfibrils?

2017 ◽  
Author(s):  
Akwasi Asamoah
Keyword(s):  
Bacterial Cellulose ◽  
Raman Spectra ◽  
Laser Power ◽  
Microfibrillated Cellulose ◽  
Glass Slide ◽  
Flax Fibre ◽  
Cellulose Microfibrils

<p>One sample of 1D bundle of cellulose microfibrils in the form of lignified flax fibre (0.10526 mm x 10 mm), and one 2D networks of cellulose microfibrils in the form of tunicate cellulose (0.07 mm x 5 mm x 10 mm), bacterial cellulose (0.135 mm x 5 mm x 10 mm) and microfibrillated cellulose (0.08 mm x 5 mm x 10 mm) were put on a glass slide parallel to the principal spectrometer axis. Raman spectra were measured all round in-plane under both half (in 5° steps) polarisation from 0° to 360° in extended mode between 100 cm<sup>-1</sup> and 1150 cm<sup>-1</sup> in 3 accumulations at 10s exposure and 100% laser power. The cursor was placed at the peak of the 1095 cm<sup>-1</sup> band, and intensity read.</p>

Sign in / Sign up

Export Citation Format

Share Document