Melting point heating rate

Compound Melting point Heating Rate rch-1) Reaction Temperature (°cr Reaction Time (days) Color Unit Cell (A) Hygrosco picity... 

When the melting point is determined in the ordinary manner, it is found to be 228-230° with decomposition. If, on approaching the melting point, the rate of heating is reduced to i° in five minutes, the value 210-212° can be observed. 

The rate of heating is the most important factor in obtaining accurate melting points. Heat no faster than 1°C per minute. 

The melting points of the derivatives of a number of amino acids are collected in Table 111,132. Most a-amino acids decompose on heating so that the melting points would be more accurately described as decomposition points the latter vary somewhat with the rate of heating and the figures given are those obtained upon rapid heating. 

These melting points are probably better described as decomposition points their values will depend somewhat upon the rate of heating. 

I) The melting point of pure maleic acid depends to a marked degree upon the rate of heating, and values between 133° and 143-144° may be observed. Slow heating (about 20 minutes) gives a value of 133-134° with more rapid heating... 

The writing process, that is, the transition crystalline — amorphous, is caused by briefly (<50 100 ns) heating up the selected storage area (diameter (( )) ca 0.5—1 Hm) by a laser pulse to a temperature above the melting point of the memory layer (Eig. 15, Record), such that the film locally melts. When cooled faster than a critical quench rate (10 -10 ° K/s), the formation of crystalline nuclei is suppressed and the melted area sohdifies into the amorphous (glass-like) state. 

Any refractory material that does not decompose or vaporize can be used for melt spraying. Particles do not coalesce within the spray. The temperature of the particles and the extent to which they melt depend on the flame temperature, which can be controlled by the fueLoxidizer ratio or electrical input, gas flow rate, residence time of the particle in the heat zone, the particle-size distribution of the powders, and the melting point and thermal conductivity of the particle. Quenching rates are very high, and the time required for the molten particle to soHdify after impingement is typically to... 

Inasmuch as the melting point of the salt varies somewhat with the rate of heating, this temperature is not particularly significant. 

Since the pinacol decomposes near its melting point the latter will vary with the rate of heating. The temperatures reported here were obtained by slow heating if the tube is placed in a bath at 150° and heated rapidly, the observed melting or decomposition point is 193-195 . 

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