The maximum normal impact resultant force(NIRF)is usually regarded as the sum of the static earth pressure of the dead zone and the dynamic impact pressure of the flowing layer.The influence of the interaction between...The maximum normal impact resultant force(NIRF)is usually regarded as the sum of the static earth pressure of the dead zone and the dynamic impact pressure of the flowing layer.The influence of the interaction between the flowing layer and dead zone on the impact force is ignored.In this study,we classified two impact models with respect to the pileup characteristics of the dead zone.Then,we employed the discrete element method to investigate the influences of the pileup characteristics on the impact force of dry granular flow on a tilted rigid wall.If the final pileup height is equal to the critical value,the maximum NIRF can be estimated using a hydrostatic model,because the main contribution to the maximum NIRF is the static earth pressure of the dead zone.If the final pileup height is less than the critical value,however,the particles in the dead zone are squeezed along the slope surface by the impact ofthe flowing layer on the dead zone,and because of shear effects,the flowing layer causes an entrainment in the dead zone.This results in a decrease in the volume of the dead zone at the moment of maximum NIRF with increases in the slope angle.As such,the maximum NIRF mainly comprises the instant impact force of the flowing layer,so hydro-dynamic models are effective for estimating the maximum NIRF.Impact models will benefit from further study of the components and distribution of the impact force of dry granular flow.展开更多
In this research, the use of borax sludge, which is generated in borax industry, as an additive in wall tile, was investigated. The wall tile samples were prepared by adding boron waste to the wall tile composition in...In this research, the use of borax sludge, which is generated in borax industry, as an additive in wall tile, was investigated. The wall tile samples were prepared by adding boron waste to the wall tile composition in the range of 2% - 10%. The effect of boron waste on the physical and mechanical properties of wall tile was determined. The results obtained were compared with the control tile and Turkish Standards (TS). The boron waste addition up to 8 wt.% was found to improve the water absorption and strength of wall tile.展开更多
Basing on some researchers' experimental results,the droplet impinging wall model was modified,and We Number and K Number were adopted to determine the mode of droplet impinging wall.The simulation results indicat...Basing on some researchers' experimental results,the droplet impinging wall model was modified,and We Number and K Number were adopted to determine the mode of droplet impinging wall.The simulation results indicated that the mode of impinging droplet is sticking on the wall in Muti-spout bed.The droplet impinging wall model modified can describe the droplet impinging wall phenomenon accurately in the multistage spouted fluidized flue gas desulfurization reactor.Basing on the study above,the distributions of temperature and relative humidity in the reactor were attained.In atomization region,the distribution of temperature exhibits "M" shape.The relative humidity exhibits"W"shape.The mass concentration of droplet reduces along axis of the reactor.Due to the multi-spouted configuration,droplet concentration increases obviously in the intersection region between the 1st and 2nd stage reaction region.The evaporating intensity reaches its peak value in the area of 200 mm away from the sprayer,and droplets are completely evaporated at 1500 mm.展开更多
Multi-walled carbon nanotube doped silica aerogels（MWCNT-SAs） were synthesized from a wet gel of well-dispersed MWCNT by one-step solvent exchange/surface modification and ambient pressure drying（APD）. Waterglass ...Multi-walled carbon nanotube doped silica aerogels（MWCNT-SAs） were synthesized from a wet gel of well-dispersed MWCNT by one-step solvent exchange/surface modification and ambient pressure drying（APD）. Waterglass was employed as a precursor to prepare wet gel. The content of MWCNT varied from 0 to 15% volume by wet gel. The surface group, thermal stability and microstructure of pure silica aerogel and MWCNT-SAs were investigated by FTIR, DTA, and TEM. Experimental results show that MWCNT-SAs are hydrophobic when the temperature is below 400 ℃, MWCNT-SAs exhibit a mesoporous network structure, and they achieve the largest scale with least shrinkage and lowest density when doped with 5 vol% MWCNT.展开更多
文摘The maximum normal impact resultant force(NIRF)is usually regarded as the sum of the static earth pressure of the dead zone and the dynamic impact pressure of the flowing layer.The influence of the interaction between the flowing layer and dead zone on the impact force is ignored.In this study,we classified two impact models with respect to the pileup characteristics of the dead zone.Then,we employed the discrete element method to investigate the influences of the pileup characteristics on the impact force of dry granular flow on a tilted rigid wall.If the final pileup height is equal to the critical value,the maximum NIRF can be estimated using a hydrostatic model,because the main contribution to the maximum NIRF is the static earth pressure of the dead zone.If the final pileup height is less than the critical value,however,the particles in the dead zone are squeezed along the slope surface by the impact ofthe flowing layer on the dead zone,and because of shear effects,the flowing layer causes an entrainment in the dead zone.This results in a decrease in the volume of the dead zone at the moment of maximum NIRF with increases in the slope angle.As such,the maximum NIRF mainly comprises the instant impact force of the flowing layer,so hydro-dynamic models are effective for estimating the maximum NIRF.Impact models will benefit from further study of the components and distribution of the impact force of dry granular flow.
文摘In this research, the use of borax sludge, which is generated in borax industry, as an additive in wall tile, was investigated. The wall tile samples were prepared by adding boron waste to the wall tile composition in the range of 2% - 10%. The effect of boron waste on the physical and mechanical properties of wall tile was determined. The results obtained were compared with the control tile and Turkish Standards (TS). The boron waste addition up to 8 wt.% was found to improve the water absorption and strength of wall tile.
基金Sponsored by the National High Technology Research and Development Program of China(Grant 2007AA05Z3374)the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period(Grant No.2006BAA01B04)
文摘Basing on some researchers' experimental results,the droplet impinging wall model was modified,and We Number and K Number were adopted to determine the mode of droplet impinging wall.The simulation results indicated that the mode of impinging droplet is sticking on the wall in Muti-spout bed.The droplet impinging wall model modified can describe the droplet impinging wall phenomenon accurately in the multistage spouted fluidized flue gas desulfurization reactor.Basing on the study above,the distributions of temperature and relative humidity in the reactor were attained.In atomization region,the distribution of temperature exhibits "M" shape.The relative humidity exhibits"W"shape.The mass concentration of droplet reduces along axis of the reactor.Due to the multi-spouted configuration,droplet concentration increases obviously in the intersection region between the 1st and 2nd stage reaction region.The evaporating intensity reaches its peak value in the area of 200 mm away from the sprayer,and droplets are completely evaporated at 1500 mm.
基金Funded by the Fundamental Research Funds for the Central Universities (No.DUT11NY11)the State Key Laboratory of Coastal and Offshore Engineering (No.LP1109)
文摘Multi-walled carbon nanotube doped silica aerogels（MWCNT-SAs） were synthesized from a wet gel of well-dispersed MWCNT by one-step solvent exchange/surface modification and ambient pressure drying（APD）. Waterglass was employed as a precursor to prepare wet gel. The content of MWCNT varied from 0 to 15% volume by wet gel. The surface group, thermal stability and microstructure of pure silica aerogel and MWCNT-SAs were investigated by FTIR, DTA, and TEM. Experimental results show that MWCNT-SAs are hydrophobic when the temperature is below 400 ℃, MWCNT-SAs exhibit a mesoporous network structure, and they achieve the largest scale with least shrinkage and lowest density when doped with 5 vol% MWCNT.
