Effect of Liquid Nitrogen Cooling and Heating on Mechanical Properties and Acoustic Emission Characteristics of Coal

Table 1

Maximum peak load of the three samples without liquid nitrogen treatment and cyclic treatment.

Sample 1		Sample 2		Sample 3
Number of cycles	Maximum peak load ()	Number of cycles	Maximum peak load ()	Number of cycles	Maximum peak load ()
Untreated	1850	Untreated	1418.603	Untreated	1850.166
3	1200.164	3	1218.603	3	1208
5	1077.741	5	1145.873	5	820.34
7	828.778	7	773.951	7	768.418
9	820.34	9	623.669	9	670.673
15	678.909	15	504.592	15	500.64