Effect of heat treatment at

Note the solution can be prepared together and then separated to aliquots of 5 ml. 

1 Put 0.4 ml of the amylase solution in each of 11 tubes, and then place the tubes into a 90°C water bath. 

2 Take out the first test tube after a certain time (min) and quickly bring it to room temperature in a cold water bath. Remove the second test tube after x min, the third after y min, and so on. Add 2 ml of 10 g l-1 buffered/nonbuffered starch at room temperature to each tube, and continue the enzymatic reaction for 3 min. 

4 Add 0.2 ml of the above mixture to 2 ml of iodine solution to develop the color, then measure the absorbance at 620 nm. 

The experiment should be performed under three conditions with buffer (Table 5.6), without buffer (only water is added) (Table 5.7), and in CaCT solution to investigate the heat stabilization of the enzymes in the presence of Ca2+ ions (Table 5.8). 

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Menard, O., and Gamier, B.G.F. (2005). Effect of heat treatment at alkaline pH on the rennet coagulation properties of skim milk. Lait 85, 515-526. 

Fig.6 The effect of heat treatment at 1073K on the fracture strength of ScSZ electrolyte.

Robock and KlosterkStter (1973) and Robock (1974) have shown that thermally stimulated luminescence of Si02 materials is extremely sensitive to surface treatment. The effect of heat treatment at 850 K on the thermally stimulated liuninescence was dependent on the gas atmosphere (air, N2, O2). 

Table 8.18 further shows the effect of heat treatment at a temperature above made on a defective SMM membrane with 35 vol% of CMS loading. 

One final test was conducted on a heat treated sample to elucidate the effect of heat treatment and sensitization on the fracture behavior of this steel. A CF sample was heated for 24 hours at 650°C to see if the fracture mode would continue to change with an even larger amount of carbide precipitation. Note in Figure 15-a this heavily sensitized steel has a fracture appearance that is completely dominated by small microvoids associated with carbides. The bimodal distribution of microvoids like those in Figure 7 has been eliminated. In fact, the fracture appearance is remarkably similar to that of the tritium-exposed-and-aged steels albeit at a different magnification (Figure 15-b). It appears that carbides in the microstructure affect the fracture mode in a similar manner as the decay helium bubbles but on a different scale. 

In a study of the effect of heat treatment upon the durability of spruce and larch heated at 200 °C in a vacuum, both spruce and larch exhibited good resistance to decay by G. trabeum, but treated spruce exhibited a decay mass loss of 9 % compared to 1 % with larch against C. puteana in an 8-week mini soil block test (Rep etal, 2004). 

Figure 9. Effect of the duration of heat treatment at I75°C on salt and water permeabilities of PVA at 30°C (A) salt permeability coefficients (O) water permeability coefficients. Open symbols refer to 100% hydrolyzed, 86,000 mol wt PVA solid symbols refer to ]00%> hydrolyzed, 115,000 mol wt PVA.

In a second part of this study, the effect of heat treatment under nitrogen of the reduced palladium catalysts A, B and C with an egg-shell type metal distribution on the metal leaching was investigated. The reduced catalysts were tested for metal leaching after they underwent a heat treatment at temperatures of 100 to 400 °C. The metal leaching of the investigated catalysts decreased after the heat treatment of... 

Fig. 28. Effect of heat treatment on the reactivity of carbon derived from petroleum pitch. Reaction of 2 g. of 6 X 8-mesh carbon with carbon dioxide at 1100°. [After P. L. Walker, Jr., and J. R. Nichols, Industrial Carbon and Graphite, Society of Chemical Industry, p. 334. London, 1957.]...

It is suggested that a detailed examination of the effect of heat-treatment temperature on the gas reactivity of the carbons studied by Walker and Baumbach 143) might show a series of reactivity maxima which correspond to temperatures at which different catalytic impurities first begin to show significant solid state diffusion and reaction with the carbon matrix followed at higher temperatures by their complete volatilization from the sample. The advent of significant diffusion and reaction of the impurity with the carbon could result in a subseiiuent increase in gas reactivity. Complete volatilization of the impurity from the sample could result in a subsequent decrease in gas reactivity. 

Amos at al.. (70) examined the effect oF heat treatment on sunflower protein. Heating of meal for 1 hour at lOO C... 

The polymer will only shrink if the applied stress is less than the frozen-in stress. If the external stress is greater than the internal stress, the sample will never shrink. Therefore distortion curves at different applied stresses are useful in the study of oriented polymer samples (e.g. drawn fibres) and the effect of heat treatments. 

Some practical cases are determination of residual stress in steel springs, the effect of mechanical loading on stress relaxation of machined and shot-peened nickel-base alloys,65 determination of residual stress level in turbine engine disks as they accumulate engine cycles,65 66 effect of manufacturing processes on residual stress, measurement of stress gradients in mechanical, electronic and structural components, effect of heat treatment on residual stress in steel coil springs, effect of variable heat treatment temperature on residual stress in iron alloys, measurement of stress in multiphase materials and composites and stress measurements at locations of stress concentrations. 

It was further found that an upstream heat treatment also helps to improve the Tg effect in milk with the casein present in micellar form, in addition to integrating the whey proteins in the gel. The increased Tg effect in milk, which was heat treated at higher levels above pasteurisation level. The same applies for milk which was UHP treated, as shown by Lauber (2002). This can be explained by the heat inactivation of a so-called Tg-inhibitor substance present in milk (De Jong et al. 2003). BOnisch et al. (2006) also proved that the inhibitor substance is located in the milk serum and demonstrated the effect of heat treatment for systems, where only the miUc serum... 

Ruminants. Aldrich and Merchen (27) studied the effect of heat treatment of whole soybean on protein digestion by mminants. They reported that increasing the extmsion temperature from 220°F to 320°F at 20°F increments resulted in a linear decrease of in situ degradation of soybean protein. As expected, raw soybean protein degraded very fast. The extent of degradation was 84.1%, 45.7%, 40%, 40.9%, 36.7%, and 30.4% for the raw, 220°F, 240°F, 260°F, 280°F, 300°F, and 320°F treatments, respectively. In other words, extmded soybean at 320°F had a bypass protein value of 69.6% as compared with 15.9% for raw soybeans. 

In degree of polymerization (DP) studies of borax treatments and ammonium dihydrogen orthophosphate (53), cellulose treated with the acid charred and depolymerized very rapidly. Its DP value decreased from 1110 to 650 after only 2 min of heating at 150 °G. Gellulose treated with borax showed a DP reduction from 1300 to 700 after 1 h of heat treatment at 150 °G. Both these compounds catalyzed the suppression of levoglucosan formation but they had different effects on the chain depolymerization reaction (53). 

A growing use of nanostructured emulsions is the delivery of bioactive lyophilized components (McClements et ah, 2007). The size of the emulsion droplets and the nature of the interface have a significant impact on the properties of the emulsions. For example, one would expect the rate of reactions that occur at an interface such as oxidation and lipolysis to increase with decreasing droplet size. However, there are conflicting reports in the literature on the effects of droplet size on these reactions. For example, there was no effect of droplet size on oxidation of structured lipid emulsions (Osborn and Akoh, 2004), no clear effects of heat treatment and droplet size on oxidation (Kiokias et ah, 2007), and a slower oxidation rate in methyl linoleate emulsions with smaller droplet size (Imai et ah, 2008). This shows that the effects of droplet size on the properties of emulsions cannot be considered in isolation from the nature of the interface. 

The effect of heat treatment on the electrokinetic behavior of powders has been emphasized by Kittaka [40,41]. Janssen and Stein [42] compared electrokinetic and charging curves of two samples of titania which underwent H2 and O2 treatment at... 

The effects of heat treatment on fimctional properties other than heat stability or gelling have received less attention. Heat treatment and pH at the time of heat treatment have an impact on the surface properties of proteins. 

The TG-DSC curves were measured on a Netzsch 409 EP Simultaneous Thermal Analysis device, using 20 mg of powdered sample. To analyse the effect of heat treatment of the samples, the experiments were carried out heating in air at a rate of 5 °C min, from ambient to lOOOT, using a-alumina as a reference. 

The effects of heat treatment temperatures on thermal conductivity, thermal conductivity at high temperatures and thermal expansion behavior have been studied. At room temperature, the value of thermal conductivity for unidirectional (UD) carbon-carbon composites is 700 W/m K. In the case of three-dimensional (3D) carbon-carbon composites, this value is determined by the volume of the fiber arrangements. On the other hand, the thermal expansion of carbon-carbon composites in the fiber axial direction is chiefly governed by the thermal expansion of the fiber. 

In the above treatment we have assumed implicitly that the alloy is at every temperature in the state of equilibrium appropriate to that temperature and to the value of the parameter V0. This, however, is in practice not necessarily the case, for it may happen that under a given set of conditions the rate of attainment of equilibrium is so slow that an equilibrium state is never in fact achieved. That this is true is, indeed, clear from observations on those systems in which a disordered state can be preserved at low temperatures by quenching, although the superstructure is then intrinsically more stable. Naturally, a discussion of the rate of attainment of equilibrium is of the greatest importance in considering the effect of heat treatment. 

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