We determi:ned a suitable gate road layout in slice mining in an ultra-thick unstable coal seam, using theoretical anallysis and numerical calculations. Based on plasticity theory in terms of limiting equilibrium, th...We determi:ned a suitable gate road layout in slice mining in an ultra-thick unstable coal seam, using theoretical anallysis and numerical calculations. Based on plasticity theory in terms of limiting equilibrium, the width of chain pillar in the upper slice was calculated to be 18 m. The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation. The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane. Three layout designs for lower gate roads were pro- posed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation. Gate road translation was determined as the most suitable layout method, which maximizes the extraction rate on the basis of the pillar stability.展开更多
Objective: The aim of our study was to determine an optimal slice thickness that was efficient in revealing bronchial imageology of pulmonary nodules (PNs) on multi-slice spiral computed tomography (MSCT) images ...Objective: The aim of our study was to determine an optimal slice thickness that was efficient in revealing bronchial imageology of pulmonary nodules (PNs) on multi-slice spiral computed tomography (MSCT) images preliminarily. Methods: Fifty-four patients with 62 PNs (diameter 〈 3 cm) underwent multidetector-row computed tomography of the chest in a single-breath-hold technique. The raw data were acquired with a collimation of 0.625 mm. Three sets of contiguous im- ages were reconstructed with 1-, 2-, and 5-mm slice thickness, respectively. Bronchial imageology of SPNs on the CT images presented in 1-, 2-, and 5-mm slice thickness was compared. Using the 1-mm sections as the gold standard, an optimal slice thickness in revealing bronchial imageology of PNs was determined. Results: Bronchial imageology of PNs on the CT images presented in 1 mm slice thickness involved 85 bronchi (35 second-fourth generation bronchi; 50 fifth-eighth generation bronchi). Bronchial imageology on 2-mm-thick sections was as same as that on I-mm-thick sections in 34 second- fourth generation bronchi. No statistically significant difference in number of second- fourth generation bronchi with same bronchial imageology was found between that on 2-mm-thick images and I-mm-thick images (P = 0.836 〉 0.05). Bronchial imageology on 5-mm-thick sections was as same as that on 1-mm-thick sections in 24 second-fourth generation bronchi. There was statistically significant difference in number of second-fourth generation bronchi with same bronchial imageology between that on 5-mm-thick images and 1-mm-thick images (P = 0.026 〈 0.05). Bronchial imageology on 2-mm-thick sections was as same as that on 1-mm-thick sections in 38 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 2-mm-thick images and 1-mm- thick images (P = 0.029 〈 0.05). Bronchial imageology on 5-mm-thick images was as same as that on I-mm-thick images in 31 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 5-mm-thick sections and I-mm-thick sections (P = 0.001 〈 0.05). Conclusion: It is suggested that the use of 2-mm slice thickness is suitable in revealing second- fourth generation bronchi and the use of l-mm slice thickness is suitable in revealing fifth-eighth generation bronchi.展开更多
The effect of varied processing variables (yam slice thickness, drying temperatures and type of drying) were investigated to determine their effects on the proximate and some functional properties of yam flour. The ...The effect of varied processing variables (yam slice thickness, drying temperatures and type of drying) were investigated to determine their effects on the proximate and some functional properties of yam flour. The yam flour was produced with different slice thickness of 1, 1.5, 2.0, 2.5 and 5 cm using both conventional sun drying method and oven drying at temperatures; 40 ~C, 50 ~C, 60 ~C and 70 ~C. The moisture content of all the yam flour samples increased with increasing yam slice thickness, with the samples sun dried having the lowest values (6.20%-6.87%) followed by those dried at 70 ~C and then 60 ~C. The protein content of the yam flour samples increased with increase in slice thickness and decreased with increase in drying temperatures while the fat and the crude fibre of all the yam flour samples decreased with increase in slice thickness. The water absorption capacity of the sun dried yam flour samples decreased with increase in slice thickness while the syneresis value, bulk density and the gel strength increased with increase in slice thickness for all drying temperatures and for sun dried yam flour samples but smaller slice thickness had higher swelling capacity.展开更多
基金provided by the Research Fund of the Fundamental Research Funds for the Central Universities of China University of Mining & Technology (No. 2010ZDP02B02)the State Key Laboratory of Coal Resources and Mine Safety (No.SKLCRSM08X2)+2 种基金the Jiangsu "333"High Qualified Talentsthe National Natural Science Foundation of China (Nos. 50904063 and51004101)the Scientific Research Foundation of China University of Mining & Technology (Nos. 2008A003 and 2009A001)
文摘We determi:ned a suitable gate road layout in slice mining in an ultra-thick unstable coal seam, using theoretical anallysis and numerical calculations. Based on plasticity theory in terms of limiting equilibrium, the width of chain pillar in the upper slice was calculated to be 18 m. The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation. The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane. Three layout designs for lower gate roads were pro- posed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation. Gate road translation was determined as the most suitable layout method, which maximizes the extraction rate on the basis of the pillar stability.
文摘Objective: The aim of our study was to determine an optimal slice thickness that was efficient in revealing bronchial imageology of pulmonary nodules (PNs) on multi-slice spiral computed tomography (MSCT) images preliminarily. Methods: Fifty-four patients with 62 PNs (diameter 〈 3 cm) underwent multidetector-row computed tomography of the chest in a single-breath-hold technique. The raw data were acquired with a collimation of 0.625 mm. Three sets of contiguous im- ages were reconstructed with 1-, 2-, and 5-mm slice thickness, respectively. Bronchial imageology of SPNs on the CT images presented in 1-, 2-, and 5-mm slice thickness was compared. Using the 1-mm sections as the gold standard, an optimal slice thickness in revealing bronchial imageology of PNs was determined. Results: Bronchial imageology of PNs on the CT images presented in 1 mm slice thickness involved 85 bronchi (35 second-fourth generation bronchi; 50 fifth-eighth generation bronchi). Bronchial imageology on 2-mm-thick sections was as same as that on I-mm-thick sections in 34 second- fourth generation bronchi. No statistically significant difference in number of second- fourth generation bronchi with same bronchial imageology was found between that on 2-mm-thick images and I-mm-thick images (P = 0.836 〉 0.05). Bronchial imageology on 5-mm-thick sections was as same as that on 1-mm-thick sections in 24 second-fourth generation bronchi. There was statistically significant difference in number of second-fourth generation bronchi with same bronchial imageology between that on 5-mm-thick images and 1-mm-thick images (P = 0.026 〈 0.05). Bronchial imageology on 2-mm-thick sections was as same as that on 1-mm-thick sections in 38 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 2-mm-thick images and 1-mm- thick images (P = 0.029 〈 0.05). Bronchial imageology on 5-mm-thick images was as same as that on I-mm-thick images in 31 fifth-eighth generation bronchi. There was statistically significant difference in number of fifth-eighth generation bronchi with same bronchial imageology between that on 5-mm-thick sections and I-mm-thick sections (P = 0.001 〈 0.05). Conclusion: It is suggested that the use of 2-mm slice thickness is suitable in revealing second- fourth generation bronchi and the use of l-mm slice thickness is suitable in revealing fifth-eighth generation bronchi.
文摘The effect of varied processing variables (yam slice thickness, drying temperatures and type of drying) were investigated to determine their effects on the proximate and some functional properties of yam flour. The yam flour was produced with different slice thickness of 1, 1.5, 2.0, 2.5 and 5 cm using both conventional sun drying method and oven drying at temperatures; 40 ~C, 50 ~C, 60 ~C and 70 ~C. The moisture content of all the yam flour samples increased with increasing yam slice thickness, with the samples sun dried having the lowest values (6.20%-6.87%) followed by those dried at 70 ~C and then 60 ~C. The protein content of the yam flour samples increased with increase in slice thickness and decreased with increase in drying temperatures while the fat and the crude fibre of all the yam flour samples decreased with increase in slice thickness. The water absorption capacity of the sun dried yam flour samples decreased with increase in slice thickness while the syneresis value, bulk density and the gel strength increased with increase in slice thickness for all drying temperatures and for sun dried yam flour samples but smaller slice thickness had higher swelling capacity.