Temperature control cooling

A microreactor was also applied to this reaction. The slit interdigital micromixer was purchased from IMM (Mainz, Germany). The width of the interdigital channels is 25 pm. HPLC pumps were used to feed the two reaction solutions. One is a mixture of Boc-AMP and 1.2 molar equivalents of r-BocaO. The other is a 50% aqueous KOH solution. The microreactor was immersed in a temperature controlled cooling bath at 15 °C. The product was quenched with an acid, and samples were taken for HPLC analysis. 

As mentioned above, the choice of substrate is crucial for tuning the lateral mobility. This problem might also be addressed in part by temperature control. Cooling can lower mobility so that the 2D gas aggregates into 2D crystals. If mobility on a particular substrate is not sufficient, it can be increased by heating. However, this could raise the probability of decomposition or desorption. Low temperatures, on the contrary, put constrain on experimental control that comes with cooling with liquid nitrogen or helium. 

When DSC scans are carried out below room temperature, or when the temperature programme is one of decreasing rather than increasing temperature, controlled cooling rather than heating of the sample and reference... 

Liquid Temperature-Control Equipment (Chillers, Mold-Temperature Controllers, Cooling Towers)... 

One common strategy for controlling column pressure is to manipulate a valve in a vent line from the reflux drum. If necessary, another line and automatic valve can be added to inject inerts, for example, nitrogen, before the vent valve. If the distillate is taken as a vapor stream, then the condenser may need to be run as a partial condenser with temperature-controlled cooling liquid on the condenser. 

The mounting position of the heat pipe determines the performance. Best performance is in the vertical working position with overhead temperature control (cooling) (Figure 2.93). 

Hence, it is necessary to correct the temperature change observed to the value it would have been if there was no leak. This is achieved by measuring the temperature of the calorimeter for a time period both before and after the process and applying Newton s law of cooling. This correction can be reduced by using the teclmique of adiabatic calorimetry, where the temperature of the jacket is kept at the same temperature as the calorimeter as a temperature change occurs. This teclmique requires more elaborate temperature control and it is prunarily used in accurate heat capacity measurements at low temperatures. 

The advantages of the above air bath are (1) simplicity and cheapness of construction (2)ease of temperature control (3) rapidity of cooling of the contents of the flask effected either by removing the asbestos covers or by completely removing the air bath and (4) the contents of the flask may be inspected by removing the asbestos covers. 

Dissolve 46-5 g. (45-5 ml.) of aniUne in a mixture of 126 ml. of concentrated hydrochloric acid and 126 ml. of water contained in a 1-htre beaker. Cool to 0-5° in a bath of ice and salt, and add a solution of 36-5 g. of sodium nitrite in 75 ml. of water in small portions stir vigorously with a thermometer (1) and maintain the temperature below 10°, but preferably at about 5° by the addition of a httle crushed ice if necessary. The diazotisation is complete when a drop of the solution diluted with 3-4 drops of water gives an immediate blue colouration with potassium iodide - starch paper the test should be performed 3-4 minutes after the last addition of the nitrite solution. Prepare a solution of 76 g. of sodium fluoborate (2) in 150 ml. of water, cool, and add the chilled solution slowly to the diazonium salt solution the latter must be kept well stirred (1) and the temperature controlled so that it is below 10°. Allow to stand for 10 minutes with frequent stirring. Filter... 

A typical flow diagram for pentaerythritol production is shown in Figure 2. The main concern in mixing is to avoid loss of temperature control in this exothermic reaction, which can lead to excessive by-product formation and/or reduced yields of pentaerythritol (55,58,59). The reaction time depends on the reaction temperature and may vary from about 0.5 to 4 h at final temperatures of about 65 and 35°C, respectively. The reactor product, neutralized with acetic or formic acid, is then stripped of excess formaldehyde and water to produce a highly concentrated solution of pentaerythritol reaction products. This is then cooled under carefully controlled crystallization conditions so that the crystals can be readily separated from the Hquors by subsequent filtration. 

Mold Coolers for Plastic Injection Molding. Heat pipes are used for local temperature control in the injection molding of plastics (see Polymerprocessing). A heat pipe is often used to force local cooling within a mold to speed operation, control viscosity, retention of material in a difficult mold area, or to reduce thermal stresses on cooling. 

In sintering, the green compact is placed on a wide-mesh belt and slowly moves through a controlled atmosphere furnace (Fig. 3). The parts are heated to below the melting point of the base metal, held at the sintering temperature, and cooled. Basically a solid-state process, sintering transforms mechanical bonds, ie, contact points, between the powder particles in the compact into metallurgical bonds which provide the primary functional properties of the part. 

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