Deep temperature equipment

Though the toxicity and vapor pressure of even dilute solutions of phosgene and the necessity for deep-temperature equipment might be considered deficiencies, we have to state that the preparation of symmetric anhydrides with phosgene and their facile and efficient use on polymer phase seem to predestinate this method of activation to the Merrifield synthesis, since all chemical problems depending on dicyclohexylcarbodiimide are circumvented, the wash-out operations (excluding sodium chloride) are simplified, and excess N-protected amino acids are to be recovered pure and in high yield. 

The thermal duty here is the opposite of solidification operations. The indirect heat-transfer equipment suitable for one operation is not suitable for the other because of the material-handling rather than the thermal aspects. Whether the temperature of transformation is a definite or a ranging one is of little importance in the selection of equipment for fusion. The burden is much agitated, but the beds are deep. 

A. 2-f2-Bmmoetkyl)-l,3-diozane (1), A 2-L, three-necked flask Is equipped with a mechanical stirrer, thermometer, and gas Inlet tube. In the flask are placed 750 ml of dichloromethane, 112 g (2.00 moll of acrolein (Note 1), and 0.10 g of didnnamalacetone Indicator (Note 2) under nitrogen. The yellow solution is cooled to 0-5°C with an Ice bath. Gaseous hydrogen bromide (Note 3) is bubbled Into the solution with stirring until the Indicator becomes deep red (Note 4). The Ice bath is removed and 1.0 g of p-toluene-sulfonic acid monohydrate and 152.2 g (2.00 mol, 144 mL) of 1,3-propanediol (Note 11 are added. The yellow solution is stirred at room temperature for 8... 

Perhaps the most striking phenomenon encountered in outer space is the wide variation in temperature that can be experienced on spacecraft surfaces and externally located equipment. Temperatures and temperature gradients not ordinarily encountered in the operation of ground or airborne structures and equipment are ambient conditions for spacecraft equipment. On such hardware, not suitably protected externally or housed deep within the space vehicle in a controlled environment, these temperature extremes can wreak destruction. Designers of earthbound... 

A laboratory oven (Note 1) is equipped with as many clay plates or enameled pie plates or trays as it will accommodate and is adjusted to operate at 98-99° (Notes 2 and 3). When the temperature has become constant the plates are removed, rapidly covered with a layer (not over 3-4 mm. deep) of pulverized (Notfe 4) hydrated oxalic acid, and then quickly replaced in the oven. The temperature will drop slightly for a few minutes (Note 5). After the oven has regained the temperature for which it was adjusted, it is heated for two hours longer at this temperature. The product is then removed, crushed if slightly caked, and quickly bottled. The yield from 100 g. of hydrated oxalic acid is 69-70 g. (96-98 per cent of the theoretical amount) (Note 6). The product is 99.5-100 per cent pure, as indicated by titration with standard alkali. 

In a 1-1. three-necked flask equipped with a mechanical stirrer, a thermometer, and a dropping funnel, and cooled externally with an ice-salt bath, is placed a solution of 118 g. (1.8 moles) of u.s.p. 85% potassium hydroxide (Note 1) in 300 ml. of water. The temperature of the solution is maintained between 0° and 10° (with the addition of ice to the flask if necessary) while 247 g. (205 ml., 2.0 moles) of 1-chloro-l-nitro-propane (Note 2) is added from a dropping funnel over a 20-minute period. The cooling bath is removed, and concentrated hydrochloric acid is added dropwise (Note 1) until the momentary green coloration produced by the addition of each drop of acid spreads rapidly throughout the solution (near a pH of 9). The temperature of the solution rises to about 70° with the separation of a deep-green oily layer. Stirring is continued until the reaction mixture reaches room temperature (about 3 hours). 

To [Co(en)2((S)-GluOBzl)]I2 (5.0 g, 7.3 X 10 3 mol) in dry trimethyl-phosphate (18 ml, 4A sieves) contained in a conical flask equipped with a drying tube was added methyl trifluoromethane sulfonate (8.0 g, 4.9 x 10 2 mol) and the mixture was stirred at room temperature for 30 min (Caution The alkylating agent is believed to be extremely toxic. Use a hood and avoid skin and vapor contact). The deep orange solution was then slowly poured into rapidly stirred dry ether (600 ml) and the precipitated semisolid recovered by decantation. The residue was dissolved in the minimum volume of dry methanol (10-20 ml), the product reprecipitated using further dry ether (400 ml), and the solid recovered as before. A further precipitation using methanol (10-20 ml) and dry ether (800 ml) produced the complex as a finely divided solid. This was recovered by filtration (porosity 4 sin-... 

Capability of remote measurements. The small size of the fiber and its electrical, chemical, and thermal inertness allow long-term location of the sensor deep inside complex equipment and thereby provide access to difficult locations where temperature may be of interest. Beyond this, however, certain of the optical techniques allow noncontact or remote sensing of temperature. 

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