Formation soaking

In steam stimulation, heat and drive energy are suppHed in the form of steam injected through weUs into the tar sand formation. In most instances, the injection pressure must exceed the formation fracture pressure in order to force the steam into the tar sands and into contact with the oil. When sufficient heating has been achieved, the injection weUs are closed for a soak period of variable length and then allowed to produce, first applying the pressure created by the injection and then using pumps as the weUs cool and production declines. 

The tubular positive plate uses rigid, porous fiber glass tubes covered with a perforated plastic foil as the active material retainer (Fig. 2). Dry lead oxide, PbO, and red lead, Pb O, are typically shaken into the tubes which are threaded over the grid spines. The open end is then sealed by a polyethylene bar. Patents describe a procedure for making a type of tube for the tubular positive plate (90) and a method for filling tubular plates of lead—acid batteries (91). Tubular positive plates are pickled by soaking in a sulfate solution and are then cured. Some proceed directiy to formation and do not requite the curing procedure. 

This process is highly suitable for rubbers with poor solubility. In this process, the rubber sheet is soaked in TEOS or quite often in TEOS-solvent mixture and the in situ sUica generation is conducted by either acid or base catalysis. The sol-gel reaction is normally carried out at room temperature. Kohjiya et al. [29-31] have reported various nonpolar mbber-silica hybrid nanocomposites based on this technique. The network density of the rubber influences the swelling behavior and hence controls the silica formation. It is very likely that there has been a graded silica concentration from surface to the bulk due to limited swelling of the rubber. This process has been predominantly used to prepare ionomer-inorganic hybrids by Siuzdak et al. [48-50]. 

Chamber saturation is recommended for better reproducibility of the separation — especially if multicomponent mobile phase mixtures are composed of solvents differing in volatility or polarity to a great extent. Moreover, chamber saturation can improve resolution of two components or reduce the formation of secondary fronts. For chamber saturation, the large tank sides are lined with a sheet of filter paper 20 X 20 cm each. Dnring the filling of the mobile phase into the chamber, it is poured onto the filter, which is then completely wetted and soaked by the mobile phase. Note that the wet filter paper is dipped into the mobile phase at the trough bottom. The prepared closed tank will become satnrated within 15 to 30 min depending on the volatihty of the solvent components (withont wetted filter paper it needs more... 

Lemna obscura fronds contain high quantities of anthocyanln that are extractable by soaking the fronds In 0.1 M HC1. L. obscura growth in the culture dish bloassay was similar to that of L. minor and appeared to be more sensitive to low levels of allelochemlcals. Anthocyanln concentration was affected by low concentrations of salicylic acid (Table VIII). Final frond number and dry weight were consistently reduced by 100 pM and 500 pM concentrations of salicylic acid whereas anthocyanln formation was inhibited by 50 UM concentrations of salicylic acid and stimulated by 0.5 VM. 

Soluble polysilane polymers can also be used as precursors to silicon carbide. The first such application, using (PhMeSi)n-(Me2Si)m copolymers ("Polysilastyrene"), was to strengthen silicon nitride ceramics. The Si3N4 ceramic body was soaked in polysilane and refired, leading to the formation of silicon carbide whiskers in the pore spaces and a consequent increase in strength. (U)... 

Fig. 6.8 The relationship between soaking cycles and amount of HAp formation. Round-shaped hydrogels were used (diameter ...

Hydroxyapatite formation on/in poly(vinyl alcohol) hydrogel matrices using an alternate soaking process. Chemistry Letters, 27, 711—712. 

Apatite formation on/in hydrogel matrixes using an alternate soaking process II. Effect of swelling ratios of poly(vinyl alcohol) hydrogel matrixes on apatite formation. Journal of Biomaterials Science-Polymer Edition, 10, 331-339. 

Taguchi, T., Kishida, A. and Akashi, M. (1999) Apatite formation on/in hydrogel matrices using an alternate soaking process (III) effect of physico-chemical factors on apatite formation on/in poly (vinyl alcohol) hydrogel matrices. Journal of Biomaterials Science—Polymer Edition, 10, 795-804. 

Fig. 11.3 Compositional dependence of hydroxyapatite formation on the glasses in the system Ca0-Si02-P205. Soaking period ...

Figures 5e and 5f show OCT images of two flax seeds (GMF) 5 minutes after being soaked in water. Multiple grouping of water transport channels with formation of lens-shaped water-bearing structures can be clearly distinguished.

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