Microseismic Temporal-Spatial Precursory Characteristics and Early Warning Method of Rockburst in Steeply Inclined and Extremely Thick Coal Seam

effect of bataine and sulphate supplement on wool and milk characteristics and lambs performance in naine ewes

تعداد 20 رأس میش نژاد نائینی 6+-24 ماهه، با میانگین وزن 2/3-+40 کیلوگرم، همراه با 20 رأس بره های آنها در قالب طرح کاملا تصادفی اثر بتائین و مکمل سولفات بر خصوصیات شیر و پشم و عملکرد بره ها بررسی شد. میش ها بطور تصادفی در چهار تیمار قرار گرفتند. تیمارها عبارت بودند از: 1-گروه شاهد 2-بتائین (05/0 درصد ماده خشک) 3-سولفات (24/0 سولفور درصد ماده خشک 4-بتائین هرماه با سولفات. جیره غذائی طبق nrc با مح...

Determination of a suitable extraction equipment in mechanized longwall mining in steeply inclined coal seams using fuzzy analytical hierarchy method (Case study: Hamkar coal mine, Iran)

The longwall mining method is one of the most applied methods in extracting low-inclined to high-inclined coal seams. Selection of the most suitable extraction equipment is very important in the economical, safety, and productivity aspects of mining operations. There are a lot of parameters affecting the selection of an extraction equipment in mechanized longwall mining in steeply inclined coal...

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

Aiming to reduce the high mining stress observed in large-space roof structures during mechanized mining of thick coal seams, a control technique based on protective-seam mining is proposed. This technique was used to investigate the 8108 working face of the No. 3–5 thick coal seam of the Tashan mine located in the Datong area of Shanxi, China, by means of simulations and field measurements. Th...

Seam Wave Characteristics in an Eastern U.S. Coal

Characteristics of Strata Behavior during Thick Seam Mining by Fully-Mechanized Top Coal Caving in a Loess-Covered Gullied Region

This study systematically investigates the overburden movement and strata behavior at a fully-mechanized top coal caving (FMTCC) face in a thick coal seam in a loess-covered gullied region by field measurement and theoretical analysis. A comparative analysis was performed to examine how the attitude of surface gullies and the structure of overburden affect face support resistance. The character...