Wet heat treatment

Deikachar, H. S. R. (1972). Effect of wet heat treatment on the culinary qualities of ragi (Eleusine coracana). ]. Food Sci. Technol. 91,49-150. 

Pasteurization is the heating of aqueous, stabilized protein solutions. Pasteurization has been used for bulk preparations of Factor VIII, antithrombin III, and alphai-antitrypsin but wet heat treatment of these... 

Plasma-derived factor VIII concentrates have been implicated in the transmission of the non-enveloped hepatitis A and parvovirus B19 (28). The virus-inactivating procedures now in use (chemical inactivation, wet-heat treatment, and nanofiltration) should provide coagulation factors without risk of transmitting HIV and with a very high safety for hepatitis virus. Nevertheless, recombinant factor VIII is considered a safer alternative. 

Despite some successes with the above pretreatments, the development of wet heat-induced epitope retrieval (HIER) procedures, which involves heating the fixed tissue sections in dilute metal-salt or buffer solutions at or above 100°C, for several minutes to 1/2 h, was the critical breakthrough in paraffin section immunohistochemistry (2, 7-9). Today, there are many variations of the original HIER technique. These differ primarily in the recommended buffer solutions and/or the source or mode of heating, but the basic formula of wet heat treatment over a fixed time period is similar. The most popular HIER technologies use microwave ovens, stainless steel or plastic pressure cookers, autoclaves, vegetable steamers or water-baths as the heat sources and low molarity buffers with acidic or alkaline pH (8,9,11-14). 

Homeffer V, Haverkamp J, Janssen H-G, Notz R. MALDI-TOL-MS analysis of bacterial spores wet heat-treatment as a new releasing technique for biomarkers and the influence of different experimental parameters and microbiological handling. J Am Soc Mass Spectrom. 2004 15(10) 1444-54. 

Thermolysis also induces cell lysis. For example, F. tularensis cell lysis has been achieved by heating the sample at 65 °C for 2 h (Lundquist et al. 2005) prior to SELDI-MS analysis. Effective release of high-mass biomarkers from Bacillus spores has been achieved using wet heat treatment. 

Several pretreatments have been used to increase the discriminatoiy power of library-based MALDI fingerprint approaches. Homeffer et al. (2004) used wet-heat treatment to extract additional analytes that facilitated strain-level resolution of B. 

Figure 6. Effects of wet heat treatment of stress-strain curve of nylon-3 fibers [11].

There are complexities. The wetting of carbon blacks is very dependent on the degree of surface oxidation Healey et al. [19] found that q mm in water varied with the fraction of hydrophilic sites as determined by water adsorption isotherms. In the case of oxides such as Ti02 and Si02, can vary considerably with pretreatment and with the specific surface area [17, 20, 21]. Morimoto and co-workers report a considerable variation in q mm of ZnO with the degree of heat treatment (see Ref. 22). 

Dyestuffs. The use of thiophene-based dyestuffs has been largely the result of the access of 2-amino-3-substituted thiophenes via new cycHzation chemistry techniques (61). Intermediates of type (8) are available from development of this work. Such intermediates act as the azo-component and, when coupled with pyrazolones, aminopyrazoles, phenols, 2,6-dihydropyridines, etc, have produced numerous monoazo disperse dyes. These dyes impart yeUow—green, red—green, or violet—green colorations to synthetic fibers, with exceUent fastness to light as weU as to wet- and dry-heat treatments (62-64). 

Fibers. Poly(vinyl alcohol) fibers possess excellent strength characteristics and provide a pleasant feel in fabrics. The fiber is usually spun by a wet process employing a concentrated aqueous solution of sodium sulfate as the coagulating bath. Water insolubiUty, even in boiling water, can be obtained by combining stretching, heat treatment, and acetalization with formaldehyde. Super hydrolyzed PVA is the preferred material for fiber production. 

Polyamides (nylons) are thermoplastic fibers that retain their form produced by heat treatment. They are usually given an alkaline scour and then heat-set. The heat-setting treatment is conducted at ca 10°C above the subsequent wet processiag steps this ensures good form retention after processiag. Woven fabrics are usually heat-set on a contact heat-setting machine and nylon tricot is generally heat-set on a tenter frame or ia steam chambers. 

Equipment should be supported in such a way that it will not rest in pools of hquid or on damp insulating material. Porous insulation should be weatherproofed or otherwise protected from moisture and spills to avoid contact of the wet material with the equipment. Specifications should be sufficiently comprehensive to ensure that the desired composition or type of material will be used and the right condition of heat treatment and surface finish will be provided. Inspection during fabrication and prior to acceptance is desirable. 

There are two basic processes for thermal tfeatment of sludge. One, wet air oxidation, is the flameless oxidation of sludge at temperatures of 450 to 550° F and pressures of about 1,200 psig. The other type, heat treatment, is similar but canied out at temperatures of 350 to 400° F and pressures of 150 to 300 psig. Wet air oxidation (WAO) reduces the sludge to an ash and heat treatment improves the dev/aterability of the sludge. The lower temperature and pressure heat treatment is more widely used than the oxidation process. 

Note The dipping solution can also be used as a spray solution. RP layers should be treated with the methanol-containing reagent on account of its better wetting properties. In addition it is necessary, particularly after the use of acidic mobile phases, to spray with alkalis, e.g. pyridine, after the heat treatment step [2, 3]. 

Solid Solid Solid-liquid Sludge, wet solid Asbestos insulation heat treatment salts, pulverized fuel ash refuse Filter cake Sewage sludge... 

In the production of wet process hardboards and serai-hardboards the press-dried boards are usually tempered or "cured" in hot air to increase their water resistance, dimensional stability, strenght and stiffness. A curing for 5 hours or more in hot air of 165°C is common. Higher curing temperatures reduce the period needed for each batch and thus increase the capacity of the heat treatment chamber, but they increase the auto-ignition risks. 

Powder metallurgical methods These include reaction of the elements and car-bothermal reduction methods. Fine powders of the metal (Hf, V, Nb, Mo, W, etc.) and carbon (graphite, lampblack) may be mixed, possibly in wet conditions with an organic solvent to be removed later, then pressed and compacted into pellets or bricks to be heated at high temperature (1800-2000°C). To perform the carbother-mal reduction, mixtures of carbon with an oxide (of Ti, V, Cr, etc.) are compacted and heated. An additional heat treatment in a high vacuum may be useful to remove O, N, etc. below a low level. 

For design of a simple manufacturing process, the thermostability of the NP enzymes is a very useful feature. Although heat treatment can be used as part of a purification protocol to isolate the enzymes from contaminating materials, the high temperature of operation itself excludes undesired enzyme-catalysed side reactions. For example, in the synthesis of 9-p-D-arabinofuranosyladenine from Ara-U and adenine, using a wet cell paste of Enterobacter aerogenes, adenine and Ara-U mainly underwent deamination at lower temperatures to form hypoxanthine and uracil respectively. At elevated temperature, deamination was completely eliminated and the rate of transarabinosylation increased. 

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