Enhanced electro-osmosis in propylene carbonate salt solutions

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Download Full-text

Bulk standards for low-temperature biological x-ray microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111525 ◽

1984 ◽

Vol 42 ◽

pp. 282-283

Author(s):

P. Echlin ◽

M. McKoon ◽

E.S. Taylor ◽

C.E. Thomas ◽

K.L. Maloney ◽

...

Keyword(s):

Phase Separation ◽

Low Temperature ◽

Analytical Method ◽

Salt Solutions ◽

Absolute Concentration ◽

Cooling Process ◽

X Ray ◽

The Absolute ◽

Analytical Procedures ◽

Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Download Full-text

Molecular simulation of osmosis, reverse osmosis, and electro-osmosis in aqueous and methanolic electrolyte solutions

Molecular Physics ◽

10.1080/002689798166729 ◽

1998 ◽

Vol 95 (3) ◽

pp. 401-408 ◽

Cited By ~ 2

Author(s):

S. MURAD K. ODER J. LIN

Keyword(s):

Reverse Osmosis ◽

Molecular Simulation ◽

Electrolyte Solutions ◽

Electro Osmosis

Download Full-text

FRÉD. GUTHRIE. — On salt solutions and attached Water (Sur les solutions salines et l'eau adhérente); Philosophical Magazine, t. XLIX, p. 1 -206-266; 1875

Journal de Physique Théorique et Appliquée ◽

10.1051/jphystap:018750040028201 ◽

1875 ◽

Vol 4 (1) ◽

pp. 282-285

Author(s):

Duclaux

Keyword(s):

Salt Solutions ◽

Philosophical Magazine

Download Full-text

Applicability of electrodialysis to the separation of sodium acetate from synthetic alkaline hardwood extract

TAPPI Journal ◽

10.32964/tj14.11.695 ◽

2015 ◽

Vol 14 (11) ◽

pp. 695-708 ◽

Cited By ~ 3

Author(s):

RAVIKANT PATIL ◽

CHI TRUONG ◽

JOSEPH GENCO ◽

HEMANT PENDSE ◽

ADRIAAN VAN HEININGEN

Keyword(s):

Current Density ◽

Sodium Sulfate ◽

Sodium Acetate ◽

Separation Efficiency ◽

Feed Concentration ◽

Initial Concentration ◽

White Liquor ◽

Complete Extraction ◽

Electro Osmosis ◽

Preliminary Separation

Our objective was to develop a process for recovering acetyl groups from industrial northeast hardwood chips. Extraction experiments showed that the white liquor charge of 6% effective alkali at 50°C and liquor-to-wood ratio of 4:1 leads to the complete extraction of acetyl groups from industrial hardwood chips. Electrodialysis was assessed as a technique for separating and concentrating sodium acetate from synthetic hardwood extract. Preliminary separation experiments using dilute sodium acetate showed that the sodium acetate can be concentrated up to approximately 24% by weight from an initial concentration of about 2% by weight. The effects of current density, feed concentration, electro-osmosis, and osmosis on the separation of sodium acetate were evaluated. Finally, selectivity experiments were performed to study the effect of various components of the white liquor on the separation of sodium acetate. Fully oxidized synthetic white liquor was used in selectivity experiments to avoid deleterious effects of Na2S. Selectivity experiments using synthetic oxidized white liquor showed a significant decrease in the separation efficiency due to the presence of sodium hydroxide, sodium carbonate, and sodium sulfate in the synthetic extract.

Download Full-text