Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were...Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were analyzed based on the settling experiments for coal-kaolinite and coal-montmorillonite suspensions,respectively,under different conditions of water hardness.The results indicate that for coal-kaolinite suspensions,as the water hardness reaches 10.0mol/L,the coal particles aggregate with each other easily,and then,the coal particles may aggregate with kaolinite particles.However,no aggregation occurs between kaolinite particles.A clay platelet network is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the network.Coal and montmorillonite particles settle completely.展开更多
This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic ...This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with p H 4.03-6.02 in Yunnan Province, Southern China. The accumulation of15 N-NO3-and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with p H 4.03 were evidently lower than those in soil with p H 4.81-6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil p H controlled nitrification more than biochar in certain strongly acidic soils.展开更多
In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the reg...In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops.展开更多
In Mediterranean countries and particularly in Southern Italy, durum wheat （Triticum durum Desf.） is traditionally used for bread production. Market globalization has created, also in these regions, the spread of br...In Mediterranean countries and particularly in Southern Italy, durum wheat （Triticum durum Desf.） is traditionally used for bread production. Market globalization has created, also in these regions, the spread of bread made with soft wheat flour （Triticum aestivum L.） standardizing this product flattening consumers＇ taste. With the aim of re-evaluating the old Sicilian local varieties, some landraces, chosen from the genebank of the institute, have been multiplied on farmers＇ fields to have enough material for making bread and for comparing this product with bread made by improved new varieties. Before milling in the pilot plant, the different wheats were characterized for their merceological indexes. The semolina obtained was analyzed for its chemical parameters. Rheological tests were conducted on dough and, finally, using standardized methods, one-variety breads were produced. On the bread slices, computerized image analysis was performed to measure colour and morphological parameters of crumb and crust. Sensory analysis, achieved through a descriptive profiling test, was conducted with trained judges using touch, fragrance and taste attributes for the different bread types. The different merceological, chemical and theological properties of raw material, grain and semolina were reflected in the breads prepared using old or improved varieties. Finally, the data obtained pointed out that the bread prepared with old and improved varieties can be clearly distinguished both by objective morphological parameters （image analysis） and by sensorial evaluations, for a potential traceability of typical product.展开更多
Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear. The most common methods for surface texatring are laser and injection molding. The 3D printi...Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear. The most common methods for surface texatring are laser and injection molding. The 3D printing method is also used to build parts, patterns, and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster, more flexible, and less expensive than traditional techniques. To date, there has been no research on textured surfaces produced by 3D printing. Therefore, a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring. In this study, a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing. The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test. The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.展开更多
基金Project(50425168)supported by the National Natural Science Foundation of ChinaProject (0100471413)supported by China Postdoctoral Science FoundationProject (201104547)supported by Pisdoctorcal Science Foundation of Jiangsu Province,China
文摘Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were analyzed based on the settling experiments for coal-kaolinite and coal-montmorillonite suspensions,respectively,under different conditions of water hardness.The results indicate that for coal-kaolinite suspensions,as the water hardness reaches 10.0mol/L,the coal particles aggregate with each other easily,and then,the coal particles may aggregate with kaolinite particles.However,no aggregation occurs between kaolinite particles.A clay platelet network is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the network.Coal and montmorillonite particles settle completely.
基金Supported by National Natural Science Foundation of China(31201688)Yunnan University’s Research Innovation Fund for Graduate Students
文摘This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with p H 4.03-6.02 in Yunnan Province, Southern China. The accumulation of15 N-NO3-and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with p H 4.03 were evidently lower than those in soil with p H 4.81-6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil p H controlled nitrification more than biochar in certain strongly acidic soils.
文摘In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops.
文摘In Mediterranean countries and particularly in Southern Italy, durum wheat （Triticum durum Desf.） is traditionally used for bread production. Market globalization has created, also in these regions, the spread of bread made with soft wheat flour （Triticum aestivum L.） standardizing this product flattening consumers＇ taste. With the aim of re-evaluating the old Sicilian local varieties, some landraces, chosen from the genebank of the institute, have been multiplied on farmers＇ fields to have enough material for making bread and for comparing this product with bread made by improved new varieties. Before milling in the pilot plant, the different wheats were characterized for their merceological indexes. The semolina obtained was analyzed for its chemical parameters. Rheological tests were conducted on dough and, finally, using standardized methods, one-variety breads were produced. On the bread slices, computerized image analysis was performed to measure colour and morphological parameters of crumb and crust. Sensory analysis, achieved through a descriptive profiling test, was conducted with trained judges using touch, fragrance and taste attributes for the different bread types. The different merceological, chemical and theological properties of raw material, grain and semolina were reflected in the breads prepared using old or improved varieties. Finally, the data obtained pointed out that the bread prepared with old and improved varieties can be clearly distinguished both by objective morphological parameters （image analysis） and by sensorial evaluations, for a potential traceability of typical product.
基金supported by the Basic Science Research Program of the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology of the Korean government(Grant No.NRF-2015R1D1A1A09060901)Ministry of Trade,Industry and Energy via FY 2015 Korea Institute for the Advancement of technology through Construction Machine R&D Expert Cultivation Program
文摘Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear. The most common methods for surface texatring are laser and injection molding. The 3D printing method is also used to build parts, patterns, and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster, more flexible, and less expensive than traditional techniques. To date, there has been no research on textured surfaces produced by 3D printing. Therefore, a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring. In this study, a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing. The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test. The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.
