in advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. the gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (edz) above the gate roadway and 2) loading effect due to the caving zone (cz) above the longwall w...

Determining the caving height in block method requires considering a suitable criterion discussed this study. The comparison between different criteria and choosing appropriate for use rock mass cavability study is main idea of study, which has not been investigated previous studies. In paper, through FEM (Finite Element Method) software, area undercutting stages was calculated using displaceme...

Taking the 14,030 panel of Zhaogu No. 2 coal mine as its research object, this paper studies evolution characteristics developing height, propagation track and caving arch shape water-flowing fractures under influence thick alluvium by utilizing a physical experiment, theoretical analysis field investigation. The results show that height limit span fracture zone experience four stages, which in...

The cave’s physical environment can be affected by tourism activities but only a few studies evaluated how recreational use may affect the cave fauna, mainly in caves with low number of visitors per year. To test hypothesis that led to changes habitat structure and invertebrate diversity, distinct scales along were analyzed. Distinct areas without human visitation analyzed transects (10 x 3 m) ...

Congenital fistulae between the tracheobronchial tree and oesophagus usually originate from the lower end of the trachea or right main bronchus. The case history is presented of a man in whom a fistula between the oesophagus and left main bronchus was not diagnosed until the age of 48.

In the present research paper we derive results about existence and uniqueness of solutions and Ulam--Hyers and Rassias stabilities of nonlinear Volterra--Fredholm delay integrodifferential equations. Pachpatte's inequality and Picard operator theory are the main tools that are used to obtain our main results. We concluded this work with applications of ob...