This paper presents a method of measuring the particle mean size and dust concentration by small angle near forward light scattering optics and the extinction theory. Its theory is based on Fraunhofer diffraction the...This paper presents a method of measuring the particle mean size and dust concentration by small angle near forward light scattering optics and the extinction theory. Its theory is based on Fraunhofer diffraction theory which is the approximation of Mie scattering within the forward Fraunhofer diffraction lobe, and Rosin Rammler function is introduced to describe the particle size distribution in two phase flow in advance. Compared with the values by the sample weight method, the measurement results have a reasonable agreement. The present work has demonstrated that this method will be probably used to monitor the parameters of two phase flow.展开更多
The influence of mean particle size on magnetic properties ofSm ( Co0.72Fe0. 15 Cu0. 1Zr0. 03 ) 7.5 sintered magnets, prepared by the conventional powder metallurgy method, was studied. With increasing ballmilling t...The influence of mean particle size on magnetic properties ofSm ( Co0.72Fe0. 15 Cu0. 1Zr0. 03 ) 7.5 sintered magnets, prepared by the conventional powder metallurgy method, was studied. With increasing ballmilling time, mean particle size decreases, specific surface increases, and sintering temperature decreases. The optimum sintering temperature of powders fabricated by baH-milling for 5, 7, 9 and 11 h are 1225, 1225, 1215 and 1215℃ respectively. The optimum value of Br, (BH)max, Hob and Hci of Sm ( Co0.72Fe0. 15 Cu0. 1Zr0. 03 ) 7.5 sintered magnets with powders ball-milling for 9 h and sintering at 1215 ℃ can reach 0.94 T, 708.4 kA·m^-1, 171.9 kJ·m^-3 and 2276.6 kA·m^-1 respectively, and the irreversible flux loss is less than 5 % after the sample ageing at 550 ℃ for 2 h, so the temperature stability improves and the magnets may be expected to be applied in the circumstances of 550 ℃.展开更多
The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 3...The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method(DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.展开更多
The authors dealt with the effects of dynamic high pressure micro-fluidization(untreated and 20-160 MPa treated) on the structure and physico-chemical properties of egg white solutions[6%(mass fraction) or 61.2 mg...The authors dealt with the effects of dynamic high pressure micro-fluidization(untreated and 20-160 MPa treated) on the structure and physico-chemical properties of egg white solutions[6%(mass fraction) or 61.2 mg protein/mL]. Micro-fluidization treatment resulted in a decrease in mean particle size, and little change in solubility. It was found that the residual denaturation enthalpy was decreased with the increase of pressure from 20 to 100 MPa and from 120 to 160 MPa, reaching into the maximum at 160 MPa. There was an increase of surface hydrophobicity with the maximum at 100 MPa observed. Simultaneously, micro-fluidization treatment also resulted in a decrease in the content of sulfhydryl groups.展开更多
Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments cond...Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield.However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition(i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese.This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage.Results: The sorghum diet reduced milk yield(P = 0.043) but not 4% fat corrected milk(P = 0.85). Feeding sorghum silage did not influence milk contents of protein(P = 0.07) and lactose(P = 0.65), and increased fat content(P = 0.024).No differences emerged for milk concentrations of saturated(P = 0.61) and monounsaturated fatty acids(P = 0.50),whereas polyunsaturated fatty acids were lower(P 〈 0.001) for the sorghum diet. Concentrations of n-6(P 〈 0.001) and n-3 fatty acids(P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the "a30"(the curd firmness, expressed in mm, 30 min after rennet addition), that was lower(P = 0.042) for the sorghum diet.Conclusions: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets.展开更多
Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selec- t...Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selec- tion methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur Bazari (SECL) and Block-II (BCCL). The drills are Rotary and Rotary Percussive type using tri- cone rock roller bits. Drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler Diagram, coarseness index (CI), mean chip size (d), specific-st trace area (SSA) and charac- teristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index (DEUI), for mapping of drill machine to bench, The developed DEU1 can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations.展开更多
文摘This paper presents a method of measuring the particle mean size and dust concentration by small angle near forward light scattering optics and the extinction theory. Its theory is based on Fraunhofer diffraction theory which is the approximation of Mie scattering within the forward Fraunhofer diffraction lobe, and Rosin Rammler function is introduced to describe the particle size distribution in two phase flow in advance. Compared with the values by the sample weight method, the measurement results have a reasonable agreement. The present work has demonstrated that this method will be probably used to monitor the parameters of two phase flow.
文摘The influence of mean particle size on magnetic properties ofSm ( Co0.72Fe0. 15 Cu0. 1Zr0. 03 ) 7.5 sintered magnets, prepared by the conventional powder metallurgy method, was studied. With increasing ballmilling time, mean particle size decreases, specific surface increases, and sintering temperature decreases. The optimum sintering temperature of powders fabricated by baH-milling for 5, 7, 9 and 11 h are 1225, 1225, 1215 and 1215℃ respectively. The optimum value of Br, (BH)max, Hob and Hci of Sm ( Co0.72Fe0. 15 Cu0. 1Zr0. 03 ) 7.5 sintered magnets with powders ball-milling for 9 h and sintering at 1215 ℃ can reach 0.94 T, 708.4 kA·m^-1, 171.9 kJ·m^-3 and 2276.6 kA·m^-1 respectively, and the irreversible flux loss is less than 5 % after the sample ageing at 550 ℃ for 2 h, so the temperature stability improves and the magnets may be expected to be applied in the circumstances of 550 ℃.
基金supported by the Inert Anode Material Production and Application in Electrolytic Production of Aluminium program of the Yunnan Aluminium Yonxin Aluminium Co. Ltd
文摘The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method(DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.
基金Supported by the National Natural Science Foundation of China(No.20666004)Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT0540)
文摘The authors dealt with the effects of dynamic high pressure micro-fluidization(untreated and 20-160 MPa treated) on the structure and physico-chemical properties of egg white solutions[6%(mass fraction) or 61.2 mg protein/mL]. Micro-fluidization treatment resulted in a decrease in mean particle size, and little change in solubility. It was found that the residual denaturation enthalpy was decreased with the increase of pressure from 20 to 100 MPa and from 120 to 160 MPa, reaching into the maximum at 160 MPa. There was an increase of surface hydrophobicity with the maximum at 100 MPa observed. Simultaneously, micro-fluidization treatment also resulted in a decrease in the content of sulfhydryl groups.
基金financed by a private company(KWS Italia Spa)located in Monselice,Italy
文摘Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield.However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition(i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese.This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage.Results: The sorghum diet reduced milk yield(P = 0.043) but not 4% fat corrected milk(P = 0.85). Feeding sorghum silage did not influence milk contents of protein(P = 0.07) and lactose(P = 0.65), and increased fat content(P = 0.024).No differences emerged for milk concentrations of saturated(P = 0.61) and monounsaturated fatty acids(P = 0.50),whereas polyunsaturated fatty acids were lower(P 〈 0.001) for the sorghum diet. Concentrations of n-6(P 〈 0.001) and n-3 fatty acids(P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the "a30"(the curd firmness, expressed in mm, 30 min after rennet addition), that was lower(P = 0.042) for the sorghum diet.Conclusions: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets.
文摘Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selec- tion methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur Bazari (SECL) and Block-II (BCCL). The drills are Rotary and Rotary Percussive type using tri- cone rock roller bits. Drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler Diagram, coarseness index (CI), mean chip size (d), specific-st trace area (SSA) and charac- teristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index (DEUI), for mapping of drill machine to bench, The developed DEU1 can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations.