Alternating solution immersion

Immersion Photografting As the name implies, the surface to be grafted is immersed in a solution containing sensitizer and monomer or alternatively solutions of each sequentially. The examples given thus far also fall into this category, regardless of the number of steps grafting has been conducted. 

Different approaches to obtaining stable layered stmctures have been proposed. One possibility consists of using a iayer-by-layer deposition method [16], schematically reported in Fig. 1.3. The growth of multilayer films is carried out by alternating the immersion of a solid conducting substrate into a cationic and then an anionic polyelectrolyte solution the excess of weakly adsorbed molecules is washed out at the end of each deposition step and the coating is dried with nitrogen or air flow before the assembly of any new layer. The preparation method is simple and can be easily automatized. 

Amino-4 -methylthiazole slowly decomposes on storage to a red viscous mass. It can be stored as the nitrate, which is readily deposited as pink crystals when dilute nitric acid is added to a cold ethanolic solution of the thiazole. The nitrate can be recrystallised from ethanol, although a faint pink colour persists. Alternatively, water can be added dropwise to a boiling suspension of the nitrate in acetone until the solution is just clear charcoal is now added and the solution, when boiled for a short time, filtered and cooled, deposits the colourless crystalline nitrate, m.p. 192-194° (immersed at 185°). The thiazole can be regenerated by decomposing the nitrate with aqueous sodium hydroxide, and extracting the free base with ether as before. 

Place 3 3oz packets of Mildewcide into a 1L flask with an electric heating mantle and cork in the neck connected to a gas bubbler immersed in at least 550mL of distilled water. Heat the paraformaldehyde (what is in the Mildewcide) to between 180-200C (a temp, regulator is absolutely necessary for this step or use a silicone oil bath). The paraformaldehyde will depolymerize making formaldehyde gas in about 91% yield. Alternatively, the gas can be bubbled through the Ammonia solution directly (only for the brave ). If the Formaldehyde solution will not be used immedi-... 

Immersion curing is used as an alternative to dry curing. Immersion curing is stiU commercially used by some small processors. The meat is placed in a brine solution for an appropriate period of time until the brine penetrates the entire portion of meat. It is important not to keep the brine for too long a period of time because the brine strength is thereby reduced and the brine becomes contaminated with meat juices and bacteria. 

After being cleaned, ware that is to be pickled is immersed successively in one or more tanks of water at 80—95°C and then transferred to the acid pickling solution. The pickling solution of 6—8% sulfuric acid is contained in a stainless steel tank or, alternatively, a lead-lined wooden tank at 60—65°C. 

The dried chromatograms are immersed in dipping solution I for 1 s, dried in a stream of warm air, dipped immediately after cooling in dipping solution II (1 s) and then heated to 100 °C for 2—3 min. Alternatively the chromatogram can be sprayed with the appropriate spray solutions. 

Nickel-iron alloys are more resistant than iron to attack by solutions of various salts. In alternate immersion tests in 5% sodium chloride solution Fink and De Croly determined values of 2-8, 0-25 and 0-5 g m d for alloys containing 37, 80 and 100% nickel compared with 46 g m d for iron. Corrosion rates of about 0.4 g m d are reported by Hatfield for Fe-30Ni alloy exposed to solutions containing respectively 5 Vo magnesium sulphate, 10 Vo magnesium chloride and 10% sodium sulphate the same alloy corroded at a rate of about 1.2 g m d in 5% ammonium chloride. 

The ASTM have established a recommended procedure for alternating-immersion stress corrosion tests in 3-5% NaCl solution (ASTM G44 1988). 

The alternating immersion may be accomplished either by moving specimens held in a suitable suspension rack into and out of containers holding the test solution, or by leaving the specimens fixed and raising and lowering the solution containers around them so as to immerse them or leave them suspended above the solution. 

Alternatively, immerse for 5 min in hot 5% ammonium acetate solution, rinse and scrub lightly. This removes PbO and PbS04. 

Similarly to quantitative determination of high surfactant concentrations, many alternative methods have been proposed for the quantitative determination of low surfactant concentrations. Tsuji et al. [270] developed a potentio-metric method for the microdetermination of anionic surfactants that was applied to the analysis of 5-100 ppm of sodium dodecyl sulfate and 1-10 ppm of sodium dodecyl ether (2.9 EO) sulfate. This method is based on the inhibitory effect of anionic surfactants on the enzyme system cholinesterase-butyryl-thiocholine iodide. A constant current is applied across two platinum plate electrodes immersed in a solution containing butyrylthiocholine and surfactant. Since cholinesterase produces enzymatic hydrolysis of the substrate, the decrease in the initial velocity of the hydrolysis caused by the surfactant corresponds to its concentration. Amounts up to 60 pg of alcohol sulfate can be spectrometrically determined with acridine orange by extraction of the ion pair with a mixture 3 1 (v/v) of benzene/methyl isobutyl ketone [271]. 

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