HOMOGENISATION

The addition of alloying elements can introduce impurities such as oxides, sulphides or carbides into the iron. In order to reduce the negative effects from these compounds, the metal is overheated at 1480 °C to 1500 °C. Nevertheless overheating can affect graphite precipitation during solidification. Homogenisation has the following positive effects  

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Bioturbation, due to the burrowing action of organisms, may connect sand layers otherwise separated by clay laminae, thus enhancing vertical permeability. On the other hand, bioturbation may homogenise a layered reservoir resulting in an unproducible sandy shale. 

Ladle metallurgy, the treatment of Hquid steel in the ladle, is a field in which several new processes, or new combinations of old processes, continue to be developed (19,20). The objectives often include one or more of the following on a given heat more efficient methods for alloy additions and control of final chemistry improved temperature and composition homogenisation inclusion flotation desulfurization and dephosphorization sulfide and oxide shape control and vacuum degassing, especially for hydrogen and carbon monoxide to make interstitial-free (IF) steels. Electric arcs are normally used to raise the temperature of the Hquid metal (ladle arc furnace). 

Rcnsl dipcptidflsc (from porcine kidney cortex) [9031-96-3] Mr 47,000 [EC 3.4.13.11]. Purified by homogenising the tissue, extracting with Triton X-100, elimination of insoluble material, and ion-exchange, size exclusion and affinity chromatography. [Hitchcock et al. Anal Biochem 163 219 7957.]... 

Attention also has to be paid to screw design. The screw metering zone should be long and shallow to ensure melt homogenisation but not so shallow that... 

Alloys were prepared by arc melting high purity starting materials followed by homogenisation. Transmission electron microscopy specimens were prepared by... 

The homogenised sample shows an increase of hardness (30%) until 400°C, where a drop to the initial value is observed. 

Qualitatively, the process of re-ordering proceeds similar in deformed and homogenised samples. Yet, two differences between deformed and recrystallized samples are observed ... 

Sueh a behaviour of metastability has been reported in the systems Cu65Pt35 and CuAu3. It has been shown that for inereased annealing time or after meehanieal deformation LRO is obtained, whereas for too short annealing times in homogenised material only the variation of SRO with temperature is deteeted. This may lead to serious misinterpretation of alloy stability if not carefully enough investigated. 

The typical for Ni-Al alloys 7R and 3R (LIq) structures of martensite were formed in the investigated alloy. The thermally induced martensite in the homogenised sample was mainly of 7R type (Fig.2b). The LIq martensitic structure was mainly observed in samples after the hot deformation. 

The ferritic steels may also undergo intercrystalline corrosion as a result of grain boundary carbide formation. In the normal softened state (treated i 800 C) the carbon is largely precipitated and the ferrite composition homogenised so that further heating at lower temperatures has no adverse effect. During solution treatment above 950 C, however, carbon is redissolved. Sensitisation can then occur at lower temperatures but the rate is so rapid that it can only be suppressed by very rapid cooling which is not practically feasible. Thus weld decay is very possible in service unless a remedial... 

Marine fouling leading to the local production of HjS increases crack growth rate, but what the effect is when combined with CP is uncertain. Some of the factors mentioned earlier in connection with other steel corrosion problems are important to sulphide stress-corrosion cracking, (SSCC), eg. compositions, particularly C which usefully can be reduced to below 0.05%, S, microstructure and segregation . Compositional homogenisation by heat treatment can be beneficial ", whilst the presence of Cu in the... 

Alloys are generally of the Al-Mg-Si type with additions of copper and chromium or manganese. Colour varies with the particular alloy and the film thickness. For optimum control of colour, the alloy must be carefully produced with strict attention to composition, homogenisation and heat-treatment, where appropriate, and the anodising conditions must be maintained within narrow limits. It is usual to arrange matters, preferably with automatic control, such that current density is held constant with rising... 

Protein concentration can be determined using a method introduced by Bradford,4 which utilises Pierce reagent 23200 (Piece Chemical Company, Rockford, IL, USA) in combination with an acidic Coomassie Brilliant Blue G-250 solution to absorb at 595 nm when the reagent binds to the protein. A 20 mg/1 bovine serum albumin (Piece Chemical Company, Rockford, IL, USA) solution will be used to prepare a standard calibration curve for determination of protein concentration. The sample for analysis of SCP is initially homogenised or vibrated in a sonic system to break down the cell walls. 

Flotation is another method to remove solid (cells) from fermentation broth, using air bubbles to float protein. We may use different kinds of high shear-force devices to make homogeneous solutions for liberating intracellular enzymes. Figure 7.8 shows several types of impeller for homogenisation. 

Based on shear forces high pressure homogeniser... 

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