Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken...Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.展开更多
Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding ...Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding are either scarce or lacking. Purpose/Aim: To assess simple means of measuring pressure under different nosebands with a view to their adoption as scientific methodology. Method: Horses (n = 7) were fitted with five different bridles (A-E). Pressure distribution and intensity were measured using colour sensitive film (Fujifilm LLLW), assessing the level of pressure and distribution across the surface of the nosebands, as assessed and ranked by independent assessors. A CURO system was also used to measure pressure in real-time under nosebands whilst riding. Results: The colour-sensitive film for D & B were ranked 1st and 2nd, respectively. Regularity of pressure overall showed a statistical difference between nosebands (A & B significantly more unregular than the others). Pressure measurements revealed significantly different means (all P Conclusions: Pressures under nosebands can reach levels that appear capable of inflicting tissue damage, hence bridles and nosebands should be assessed using scientific methodology and not based on arbitrary and subjective criteria, as is currently the case.展开更多
文摘Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.
文摘Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding are either scarce or lacking. Purpose/Aim: To assess simple means of measuring pressure under different nosebands with a view to their adoption as scientific methodology. Method: Horses (n = 7) were fitted with five different bridles (A-E). Pressure distribution and intensity were measured using colour sensitive film (Fujifilm LLLW), assessing the level of pressure and distribution across the surface of the nosebands, as assessed and ranked by independent assessors. A CURO system was also used to measure pressure in real-time under nosebands whilst riding. Results: The colour-sensitive film for D & B were ranked 1st and 2nd, respectively. Regularity of pressure overall showed a statistical difference between nosebands (A & B significantly more unregular than the others). Pressure measurements revealed significantly different means (all P Conclusions: Pressures under nosebands can reach levels that appear capable of inflicting tissue damage, hence bridles and nosebands should be assessed using scientific methodology and not based on arbitrary and subjective criteria, as is currently the case.
