Vacuum heating

Ga20 a-Ga203 reduction of Ga203 with Ga at 500—600°C, under vacuum heating GaOOH at 300—500°C trigonal, R3C (comndum a-A103)... 

Dilute glycerol Hquors, after purification, are concentrated to cmde glycerol by evaporation. This process is carried out in conventional evaporation (qv) under vacuum heated by low pressure steam. In the case of soap—lye glycerol, means are suppHed for recovery of the salt that forms as the spent lye is concentrated. Multiple effort evaporators are typically used to conserve energy while concentrating to a glycerol content of 85—90%. 

Table 3. Vanadium Prepared by Dealuminization with Vacuum Heating ...

An amine-terminated poly ether (ATPE) is prepared as follows. Charge poly(tetramethylene oxide) diol (PolyTHF 1000, BASF, 75.96 g, 0.0759 m) to a 500-mL three-neck round-bottom flask fitted with a thermocouple, a mechanical stirrer, and a vacuum port. Add tert-butylacetoacetate (24.04 g, 0.1582 m) and apply vacuum. Heat at 175° C for 4 h, Fourier transform infrared (FTIR) analysis should indicate complete loss of the polyol OH absorption at 3300 cm. The room temperature viscosity of the product should be about 520 mPa-s. React this acetoacetylated product (85.5 g, 0.0649 m) with cyclohexylamine (14.5 g, 0.1465 m) at 110° C under vacuum for several hours. Cool the resultant cyclohexylaminocrotonate poly ether product to room temperature (1790 mPa-s at room temperature). 

Drier, drum, vacuum heat surface area, 1-10 m 0.55-0.80... 

For work where it is critical to examine the properties of the chemically modified wood with the certainty that there are no by-products or solvents present, it is advisable not to rely solely on an oven-drying stage, or on vacuum-heating. More effective extraction can be achieved with the use of Soxhlet apparatus followed by oven-drying. However, the efficiency of this process is very dependent upon sample size and the scale at which the work is being performed. To ensure total removal of residual chemicals, it is usually a good idea... 

Following the period of vacuum heating, the samples were re-weighed. Several of the samples were analyzed for chemical purity in order to determine the presence of decompn products... 

GC is arguably the most common carbon electrode material in current use, and its applications are too extensive to list here in any comprehensive fashion. Examples are listed here to illustrate GC electrode performance, particularly for voltammetry. Figure 10.12 shows the effect of vacuum heat treatment on ascorbic acid oxidation on initially polished GC [41]. Note that the less positive peak... 

GOST Standard 24956-81. Titanium alloys Determination of hydrogen in solid metal via vacuum heating. GOSSTANDART, Moscow 1989 (Russia)... 

Hein, W., Loehberg, K. Application of the gas chromatographic method of Janak to the analysis of gas in cast iron and steel after high-vacuum heat extraction. Gies-serei, Techn.-Wiss. Beih. Giessereiw. Metallk. 13, 221 (1961). — Chem. Abstr. 62,... 

Thus, in vacuum, heating of Ca(I03)2 would produce Cal2. In air, the first reaction is not displaced appreciably to the right below 510°C.22 For this reason the calculation of the equilibrium constant for reaction (a) is somewhat misleading since it suggests appreciable decomposition of Ca(I03)2... 

---