The Formation of Stable Sols from Laponite, A Synthetic Hectorite-Like Clay

Clay Minerals ◽  
1970 ◽  
Vol 8 (4) ◽  
pp. 389-404 ◽  
Author(s):  
B. S. Neumann ◽  
K. G. Sansom
Keyword(s):  
Chemical Theory ◽  
Sol Stability

AbstractThe effects of simultaneous additions of electrolyte and peptiser to dispersions of the synthetic hectorite-like clay, Laponite, have been studied. It has been unexpectedly discovered that whereas many cations cause gelling and flocculation of the dispersions as expected by colloid chemical theory, some cations actually stabilize the sols obtained with peptiser. A relationship has been found between the effectiveness of the cations in increasing sol stability and their size and charge.The effects of time, temperature and peptiser concentration have also been examined, and explanations are offered for the phenomena observed.

Short-range order and concentration fluctuations in binary molten alloys

1987 ◽  
Vol 65 (3) ◽  
pp. 309-325 ◽  
Author(s):  
R. N. Singh
Keyword(s):  
Lattice Theory ◽  
Order Parameter ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Concentration Fluctuations ◽  
Mixing Properties ◽  
Chemical Theory ◽  
Local Ordering ◽  
Interchange Energy

The quasi-chemical theory and the quasi-lattice theory are discussed with a view to obtaining information about concentration fluctuations, SCC(0), and the short-range order parameter, α1, for regular and compound-forming molten alloys. The influence of the coordination number z and the interchange energy ω on the mixing properties of the alloy is critically examined. SCC(0) and α1 have been found to be very useful in extracting microscopic information, like local ordering and segregation in molten systems. The problem of glass formation in compound-forming binary molten alloys is also briefly discussed.

Assessment on the Transport of Polymeric Solution through High-Salinity Reservoirs Containing Divalent Cations

2013 ◽  
Vol 807-809 ◽  
pp. 2607-2611
Author(s):  
Byung In Choi ◽  
Moon Sik Jeong ◽  
Kun Sang Lee
Keyword(s):  
Quantitative Assessment ◽  
High Salinity ◽  
Divalent Cations ◽  
Polymer Concentration ◽  
Field Application ◽  
Polymer Flooding ◽  
Sweep Efficiency ◽  
Chemical Theory ◽  
Bottom Hole ◽  
Reservoir Conditions

Water salinity and hardness have been regarded as main limitation for field application of polymer floods. It causes not only reduction of polymer concentration, but also injectivity loss in the near wellbore. Based on the mathematical and chemical theory, extensive numerical simulations were conducted to investigate performance of polymer floods in the high-salinity reservoirs. According to results from simulations, the high salinity reduces the viscosity of polymer in contacting area. That causes a poor sweep efficiency of polymer flooding. Moreover, the presence of divalent cations makes the project of polymer flooding worse. That is because of excessively increased bottom-hole pressure in injection well by the precipitation of polymer. The quantitative assessment of polymer floods needs to be required before field application. Therefore, the results in this paper are helpful for optimal polymer flooding design under harsh reservoir conditions.

3. Note on Solar Radiation

1888 ◽  
Vol 14 ◽  
pp. 118-121
Author(s):  
John Aitken
Keyword(s):  
Solar Radiation ◽  
The Sun ◽  
Geological History ◽  
Conservation Of Energy ◽  
Vast Amount ◽  
Chemical Theory ◽  
Energy Theory ◽  
The Many ◽  
Different Sources

In the many theories that have been advanced to explain the comparative constancy of solar radiation in long past ages as evidenced by geological history, it has been generally assumed that the temperature of the sun has not varied much, and to account for its not falling in temperature a number of theories have been advanced, all suggesting different sources from which it may have received the energy which it radiates as heat. Since the chemical theory was shown to be insufficient to account for the vast amount of heat radiated, other theories, such as the meteoric theory and the conservation of energy theory, have been advanced.

Studies in the Vulcanization of Rubber. IV—A Theory of Vulcanization of Rubber

1930 ◽  
Vol 3 (4) ◽  
pp. 659-667
Author(s):  
G. R. Boggs ◽  
J. T. Blake
Keyword(s):  
Electrical Properties ◽  
Joule Effect ◽  
Vulcanized Rubber ◽  
Chemical Theory ◽  
Rubber Compounds ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization

Abstract A new theory has been advanced which, it is believed, explains completely the various phenomena connected with the vulcanization of rubber. It is entirely a chemical theory based on the existence of two separate and distinct rubber compounds, soft vulcanized rubber and ebonite. The theory explains satisfactorily the aging of rubber, the variation in combined sulfur at optimum cure caused by acceleration, the kinetics of vulcanization, the characteristics of various vulcanizing agents, the thermochemistry of vulcanization, the electrical properties of rubber, the reclaiming of rubber, and the Joule effect. A brief review and discussion of the phenomena and past theories of vulcanization have also been given.

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