Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in...Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in Al 1100 alloy has been studied in detail.Before subjecting to 50%cryorolling,samples were pre-annealed at 250℃ for 2 h and pre-solution treated at 540℃ for 1 h.X-ray diffraction and HRTEM techniques were used to understand the crystallite size,lattice strain and dislocation configuration in the processed alloy.The results indicate that the pre-annealed sample has the highest grain aspect ratio(4.43),the smallest crystallite size(37.53 nm),the highest lattice strain(9.12×10^(−3))and the highest dislocation density(45.16×10^(13) m^(−2))among the tested sample.The pre-annealed sample shows a significant improvement of 43.44%,24.64%and 20.33%in hardness,ultimate tensile strength and yield strength.Both pre-annealed and pre-solution treated samples show improved corrosion resistance when compared to cryorolled samples without any pre-treatment,with the pre-annealed sample showing the best corrosion resistance.展开更多
Background:Conventional drying using heated air oven is commonly used as a method for preserving the product but often affects the nutritional value,taste,and texture.However,the heat from the drying method can oxidiz...Background:Conventional drying using heated air oven is commonly used as a method for preserving the product but often affects the nutritional value,taste,and texture.However,the heat from the drying method can oxidize and destroy heat-sensitive compounds.Superheated steam(SHS)drying uses superheated steam instead of hot air or combustion gases in a direct dryer and was reported better at preserving the nutritional values of food products.Aim:To evaluate the effect of SHS drying on antioxidant properties of tea leaves.The study also compared SHS drying with conventional and freeze-drying methods.Results:Tea leaves dried using freeze drying retained the highest level of antioxidant properties compared to other drying methods.The leaves dried using SHS exhibited significantly higher radical scavenging activity,ORAC and FRAP values compared to oven drying method.At different drying temperatures(150℃and 175℃),oven dried leaves showed significantly higher(p<0.05)antioxidant properties than that of SHS dried ones.Tea leaves dried for 60,75,and 90 min using SHS showed significantly higher(p<0.05)FRAP and ORAC values,and also total phenolic content compared to oven dried tea leaves.Conclusion:Tea leaves dried using SHS drying method retained higher level of antioxidant properties compared to oven drying.The drying method also retained lower antioxidant properties as drying time increased.Further study involving SHS drying in food-related fields should be conducted to support its usefulness.展开更多
基金Universiti Sains Malaysia for providing the fund for this study under RU grant No.1001/PBahan/8014105.
文摘Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in Al 1100 alloy has been studied in detail.Before subjecting to 50%cryorolling,samples were pre-annealed at 250℃ for 2 h and pre-solution treated at 540℃ for 1 h.X-ray diffraction and HRTEM techniques were used to understand the crystallite size,lattice strain and dislocation configuration in the processed alloy.The results indicate that the pre-annealed sample has the highest grain aspect ratio(4.43),the smallest crystallite size(37.53 nm),the highest lattice strain(9.12×10^(−3))and the highest dislocation density(45.16×10^(13) m^(−2))among the tested sample.The pre-annealed sample shows a significant improvement of 43.44%,24.64%and 20.33%in hardness,ultimate tensile strength and yield strength.Both pre-annealed and pre-solution treated samples show improved corrosion resistance when compared to cryorolled samples without any pre-treatment,with the pre-annealed sample showing the best corrosion resistance.
基金supported by the School of Graduate Studies and the Department of Nutrition and Dietetics of Universiti Putra Malaysia(Malaysia),in collaboration with the Graduate School of Life Science and System Engineering of Kyushu Institute of Technology(Japan).
文摘Background:Conventional drying using heated air oven is commonly used as a method for preserving the product but often affects the nutritional value,taste,and texture.However,the heat from the drying method can oxidize and destroy heat-sensitive compounds.Superheated steam(SHS)drying uses superheated steam instead of hot air or combustion gases in a direct dryer and was reported better at preserving the nutritional values of food products.Aim:To evaluate the effect of SHS drying on antioxidant properties of tea leaves.The study also compared SHS drying with conventional and freeze-drying methods.Results:Tea leaves dried using freeze drying retained the highest level of antioxidant properties compared to other drying methods.The leaves dried using SHS exhibited significantly higher radical scavenging activity,ORAC and FRAP values compared to oven drying method.At different drying temperatures(150℃and 175℃),oven dried leaves showed significantly higher(p<0.05)antioxidant properties than that of SHS dried ones.Tea leaves dried for 60,75,and 90 min using SHS showed significantly higher(p<0.05)FRAP and ORAC values,and also total phenolic content compared to oven dried tea leaves.Conclusion:Tea leaves dried using SHS drying method retained higher level of antioxidant properties compared to oven drying.The drying method also retained lower antioxidant properties as drying time increased.Further study involving SHS drying in food-related fields should be conducted to support its usefulness.
