Cooling time

If the heating time t or cooling time t are non-zero, or if the run time tj. is non-zero and constant temperature is selected, velocities are adjusted (rescaled) during the molecular dynamics run to change the temperature of the system. 

There are important figures of merit (5) that describe the performance of a photodetector. These are responsivity, noise, noise equivalent power, detectivity, and response time (2,6). However, there are several related parameters of measurement, eg, temperature of operation, bias power, spectral response, background photon flux, noise spectra, impedance, and linearity. Operational concerns include detector-element size, uniformity of response, array density, reflabiUty, cooling time, radiation tolerance, vibration and shock resistance, shelf life, availabiUty of arrays, and cost. 

Overcurrent protection. To provide a thermal replica protection, the relay is set according to motor s heating and cooling (/ - 1) curves supplied by the motor manufacturer. If these curves are not available, they can be established with the help of motor heating and cooling time constants, as in equations (3.2) and (3.4). A brief procedure to establish the motor thermal curves when they are not available is explained in Section 3.6. 

When 150 SSU at 100°F (38°C) oil is necessary, inlet temperatures should be limited to 110-120°F (43 9° C) to maintain an acceptable viscosity. Oil should be supplied in the temperature and pressure range specified by the manufacturer. Up to a pitch-line speed of approximately 15,000 feet per minute (4572 mpm) the oil should be sprayed into the out-mesh. Spraying allows maximum cooling time for the gear blanks and applies the oil at the highest temperature area of the gears. Also, a negative... 

The above analysis illustrates how to estimate the cooling time using the relationship between the temperature gradient AT and the Fouriers Number... 

During the blow moulding of polypropylene bottles, the parison is extruded at a temperature of 230°C and the mould temperature is 50°C. If the wall thickness of the bottle is I mm and the bottles can be ejected at a temperature of I20°C estimate the cooling time in the mould. 

The problem of the cooling of hot vessels within a desiccator is also important. A crucible which has been strongly ignited and immediately transferred to a desiccator may not have attained room temperature even after one hour. The situation can be improved by allowing the crucible to cool for a few minutes before transferring to the desiccator, and then a cooling time of 20-25 minutes is usually adequate. The inclusion in the desiccator of a metal block (e.g. aluminium), upon which the crucible may be stood, is also helpful in ensuring the attainment of temperature equilibrium. 

Time, pressure, and temperature controls indicate whether the performance requirements of a molded product are being met. The time factors include the rate of injection, duration of ram pressure, time of cooling, time of piastication, and screw RPM. Pressure requirement factors relate to injection high and low pressure cycles, back pressure on the extruder screw, and pressure loss before the plastic enters the cavity which can be caused by a variety of restrictions in the mold. The temperature control factors are in the mold (cavity and core), barrel, and nozzle, as well as the melt temperature from back pressure, screw speed, frictional heat, and so on in the plasticator. 

Desktop tools address design and manufacturing concerns such as gate placement, injection time/rate, injection pressure, melt and mold temperatures, packing time and pressure, cooling time requirements, and machine size requirements. 

Therrtial Sterilization of Pouches of Beef. Methodology for food thermoprocessing in cylindrical metal containers assured food sterility in flexible packages. Beef slices (1.25 cm thick) were steam cooked to an internal temperature of 72°C and vacuum sealed in pouches to give a fill of 120 g. These pouches of beef were processed in a standard retort with complete water circulation and a superimposed air pressure of 1.7 X 105 Pa. The retort schedule—a 40-minute cook at 118°C plus come-up time followed by a 30-minute cooling time—achieved a F0 (lethality value) of 6. 

Figure 1. Bow development for two cooling histories of the composite panel. At the figure, the bow (m) is plotted versus cooling time (sec) for two cooling regimes. (Reprinted with permission from ref. 7. Copyright 1986 SPI, Inc.)...

Shortly after closing the twist-off lids or sealing the tins, at least on the same day of filling, the jars or tins are sterilized by autoclaving for 30 min at I20°C, whilst maintaining a pressure of 2 bar. The cooling time is 30 min. A disadvantage of the... 

Opportunities for lower cost through research and development, and as a result of the much longer cooling time for spent fuel to be reprocessed. 

Forced air, water mist, or water spray cool the mold after it leaves the oven. Once the mold [. cools sufficiently for the polymer inside to solidify, it is opened. The cooling time must take. into account the resin, the wall thicknesses, and the metal from which the mold is fabricated, ff.. Very rapid cooling of the mold can introduce stresses that can weaken or distort the final part. 

A large neutron cross section of 235U for fission (5.8 x 10 26 m2), a high fission yield (6%) for "Tc, and a long half-life of the resulting "Tc (2.1 x 105 yr) make this radionuclide one of the principal nuclear wastes. Fig. 1 shows radioactivity of nuclear wastes plotted against cooling time in years. Tc activity is very important in the time interval 104-106 years. 

The above findings are quite significant since they indicate a clear way to design solvent evaporation in the bed when the binder is a solution or the cooling time when the binder is a melt. One has to stress, however, that the above estimates are probably not very general and may require corrections for different pairs of powders and binders. Since the experimental procedure and the instrument are quite simple and straightforward to use, such measurements should be easy to perform for each specific case. 

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