On pseudo-clathrate hydrate structure in aqueous solutions of tetrahydrofuran

1979 ◽  
Vol 8 (5) ◽  
pp. 371-375 ◽  
Author(s):  
S. R. Gough
Keyword(s):  
Aqueous Solutions ◽  
Clathrate Hydrate

Clathrate hydrate equilibria in mixed monoethylene glycol and electrolyte aqueous solutions

2012 ◽  
Vol 48 ◽  
pp. 7-12 ◽  
Author(s):  
Antonin Chapoy ◽  
Saeid Mazloum ◽  
Rod Burgass ◽  
Hooman Haghighi ◽  
Bahman Tohidi
Keyword(s):  
Aqueous Solutions ◽  
Clathrate Hydrate ◽  
Monoethylene Glycol

Experimental Clathrate Hydrate Dissociation Data for Systems Comprising Refrigerant + CaCl2 Aqueous Solutions

2016 ◽  
Vol 61 (2) ◽  
pp. 827-836 ◽  
Author(s):  
Peterson Thokozani Ngema ◽  
Paramespri Naidoo ◽  
Amir H. Mohammadi ◽  
Dominique Richon ◽  
Deresh Ramjugernath
Keyword(s):  
Aqueous Solutions ◽  
Clathrate Hydrate ◽  
Hydrate Dissociation

scholarly journals Semi-clathrate hydrate phase stability conditions for methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) + water system: Experimental measurements and thermodynamic modeling

2021 ◽  
Vol 76 ◽  
pp. 75
Author(s):  
Hamideh Irannezhad ◽  
Jafar Javanmardi ◽  
Ali Rasoolzadeh ◽  
Khayyam Mehrabi ◽  
Amir H. Mohammadi
Keyword(s):  
Phase Equilibrium ◽  
Aqueous Solutions ◽  
Mass Fraction ◽  
Tetrabutylammonium Bromide ◽  
Clathrate Hydrate ◽  
Clathrate Hydrates ◽  
Stability Conditions ◽  
Equilibrium Conditions ◽  
Hydrate Phase ◽  
Mass Fractions

One of the promising applications of clathrate/gas hydrates is the transport and storage of natural gas. Semi-clathrate hydrates have received more attention due to milder pressure/temperature stability conditions compared to ordinary clathrate hydrates. The most commonly reported semi-clathrate hydrates are formed from a combination of gas + water + quaternary ammonium salts. In this work, a total of 53 equilibrium data for semi-clathrate hydrates of methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) aqueous solutions were experimentally measured. For TBAB, three concentrations including 0.0350, 0.0490, and 0.1500 mass fractions were used. For TBAA, a solution with a 0.0990 mass fraction was used. Additionally, the modified Chen–Guo model was applied to calculate the hydrate phase equilibrium conditions of methane + TBAB/TBAA aqueous solutions. The model can accurately calculate the aforementioned semi-clathrate hydrate phase equilibrium conditions with the Average Absolute Deviations ((AAD)T and (AAD)P) of 0.1 K and 0.08 MPa, respectively. The temperature increments for 0.0350, 0.0490, and 0.1500 mass fractions of TBAB are 7.7, 9.4, and 13.5 K, respectively. This value for 0.0990 mass fraction of TBAA is 6.2 K. Therefore, it is concluded that TBAB is a stronger hydrate promoter compared to TBAA.

Ultrathin frozen sections of yeast without aldehyde prefixation

1978 ◽  
Vol 36 (2) ◽  
pp. 58-59
Author(s):  
K. J. Böhm ◽  
a. E. Unger
Keyword(s):  
Aqueous Solutions ◽  
Biological Material ◽  
Yeast Cells ◽  
Frozen Sections ◽  
Good Preservation ◽  
Ultrathin Frozen Sections

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

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