Soak periods

Soa.king. The hides are weighed and counted into production batches. For pre-fleshed and trimmed catde hides the batches are about 3—5 t when the processing is in dmms. If the tannery has hide processors the batches may be up to 10 t. Water is added to cover the hides and allow free movement of the load. The dmm is turned intermittently during the normal 8 to 16-hour soaking period. 

Another method of using CO2 is called cycHc CO2 stimulation or huff n puff (26). A limited amount of CO2 is iajected into a reservoir over hours or days. The well is then shut in for a soak period of days to weeks to allow the CO2 to interact with the cmde oil, swelling the oil and reducing its viscosity. 

Eig. 2. Cychc steam stimulation of an oil well (a) steam, injected into a well over a period of days or weeks in a heavy oil reservoir, introduces heat (huff) that, coupled with (b), alternate soak periods lasting a few days to allow (c) a production phase of weeks or months (puff), thins the oil. This process may... 

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. 

To date (ca 1997), steam methods have been appHed almost exclusively in relatively thick reservoirs containing viscous cmde oils. In the case of heavy oil fields and tar sand deposits, the cycHc steam injection technique has been employed with some success. The technique involves the injection of steam at greater than fracturing pressure, usually in the 10.3—11.0 MPa (1500—1600 psi) range, foUowed by a soak period, after which production is commenced (15). 

In the original process for the positive electrode, the plaques were placed in a metal vessel, which was evacuated to <5.3 kPa (40 mm Hg), and a nearly saturated solution of nickel nitrate (density 1.6 g/mL) admitted. After a 5—15 min soaking period, the plaques were transferred at 101 kPa (1 atm) to a polarizing unit where they were cathodicaHy polarized in hot caustic solution. After polarization the plates were washed and dried. These four steps were repeated four or five times until the desired weight gain of active material was achieved. 

A key parameter in the design of the fuel vapor control system is the volume of activated carbon required to meet the emission standards for the various regulatory tests. In the case of the three-day diurnal test sequence, the emission limits are 0.05 grams of HC per mile during the run loss portion of the test (maximum emission -0.85 grams), and a maximum release of 2.0 grams for the sum of the hot soak period and any one of the three 24-hour periods making up the diurnal test sequence. 

To obtain the phosphorylated chitin, fibres were soaked in saturated Ca(OH)2 solution (pH 12.4) for 8 days. The Ca(OH)2 solution was renewed every 4 days. After completion of the soaking period, the fibres were washed, filtered and dried under vacuum at 60 °C. This technique of phosphorylation and Ca(OH)2 treatment has been found to be a useful method for creating favorable local conditions leading to the nucleation and growth of calcium... 

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

It was observed that the NIR-predicted monomer concentration varied greatly during the first 45 minutes after monomer addition but then stabihzed this was attributed to slow solubilization of large monomer droplets into the water phase, and slow partition of monomer between the water phase and the latex phase, leading to large local variations in monomer concentration. This was avoided by allowing a 60-minute soak period after monomer addition, before the temperature was increased to start the polymerization. 

After the two-hour cold soak period, the volume of fuel in the test cylinder is measured. After measurement, the test cylinder is inverted so that the section containing fuel is on the top and the empty section rests on the bottom of the test well. Care should be taken not to touch the section of the test cylinder containing the fuel. Also, if the test cylinder must be removed from the cold well for measurement and inversion, minimize the removal time. 

ABS decomposes in a rapid single step reaction, which is complete around 600°C. Disordered carbon materials were synthesized by the pyrolysis of ABS at 600,700,800 and 900°C in an argon atmosphere. The heating rate was l°C/min for a soak period of 1 h. 

Ivory nut mannan such as that from palm seed is the only identified water insoluble food reserve polysaccharide which occurs in nearly pure form. It dissolves in 5% alkaline solution, and its food reserve nature is indicated by its disappearance when the seed germinates. Perhaps its lack of solubility permits the palm seeds to withstand rather long soaking periods before germination. Most other mannans found in other biological sources are branched and more readily water soluble. 

An HDPE sample together with aliquots of TBPB/styrene solution (0.3 mol % TBPB) were sealed in stainless-steel-high pressure vessels that were purged with C02 gas, tared, and heated to the soak temperature of 80 °C. A heated high-pressure C02 manifold was used to pressurize the vessel to 243 bar. The vessel was then weighed to determine the mass of C02 transferred and then heated for 5 h at 80 °C. The styrene in C02 concentration was 28 wt %. After this initial soaking period, the vessel was heated to 100 °C and maintained at this temperature for the desired reaction time. The vessel was then vented, refilled with nitrogen, and maintained at 100 °C for 6 h. 

A typical two-stage RO skids can take 8-12 hours to clean, depending on the time it takes to heat up the cleaning chemical solutions. If an extended soak time is required, it can take even longer, up to 24 hours, including the soak period (see Chapter 13.2.2). Each stage in a skid should be cleaned independently of the other(s) so as not to contaminate one stage with foulants or scale from another, which is why it may take a day or so to clear an entire system. 

Cleaning at lower temperatures is not recommended. Cleaning solutions are typically not effective at ambient temperatures and some components of the solution may even precipitate at these temperatures. Hence, a longer soak will not compensate for cleaning at lower temperatures. In fact, during extended soak periods at higher temperatures, a slow recirculation is recommended to maintain temperature. 

The soaking period like the evacuation period depends upon the... 

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