Dissimilar friction stir welding between AZ31-O Mg and 6061-T6 Al alloys was investigated. 3 mm thick plates of aluminum and magnesium were used. Friction stir welding operations were performed at different rotation a...Dissimilar friction stir welding between AZ31-O Mg and 6061-T6 Al alloys was investigated. 3 mm thick plates of aluminum and magnesium were used. Friction stir welding operations were performed at different rotation and travel speeds. The rotation speeds varied from 600 to 1400 r/min, and the travel speed varied from 20 to 60 mm/min. Defect-free weld was obtained with a rotation speed of 1000 r/min and travel speed of 40 mm/min. Metallographic studies showed that the grain size in the stir zone is much finer than that in the base metals. Complex flow pattern was formed in the stir zone. Microhardness measurement revealed an uneven distribution in the stir zone. Tensile test results indicated that the tensile strength of the welded specimen is about 76% of AZ31 Mg alloy and 60% of the 6061 Al alloy in tensile strength. SEM fracture surface image of the welded specimen indicated that the welded specimen failed through brittle-mode fracture.展开更多
Background Recently,beneficial effects of probiotics and/or prebiotics on cardio-metabolic risk factors in adults have been shown.However,existing evidence has not been fully established for pediatric age groups.This ...Background Recently,beneficial effects of probiotics and/or prebiotics on cardio-metabolic risk factors in adults have been shown.However,existing evidence has not been fully established for pediatric age groups.This study aimed to assess the effect of synbiotic on anthropometric indices and body composition in overweight or obese children and adolescents.Methods This randomized double-blind,placebo-controlled trial was conducted among 60 participants aged 8-18 years with a body mass index(BMI)equal to or higher than the 85th percentile.Participants were randomly divided into two groups that received either a synbiotic capsule containing 6x109 colony forming units(CFU)Lactobacillus coagulans SC-208,6 x 109 CFU Lactobacillus indicus HU36 and fructooligosaccharide as a prebiotic(n=30)or a placebo(n=30)twice a day for eight weeks.Anthropometric indices and body composition were measured at baseline and after the intervention.Results The mean(standard deviation,SD)age was 11.07(2.00)years and 11.23(2.37)years for the placebo and synbiotic groups,respectively(P=0.770).The waist-height ratio(WHtR)decreased significantly at the end of the intervention in comparison with baseline in the synbiotic group(0.54±0.05 vs.0.55±0.05,P=0.05).No significant changes were dem-onstrated in other anthropometric indices or body composition between groups.Conclusions Synbiotic supplementation might be associated with a reduction in WHtR.There were no significant changes in other anthropometric indices or body composition.展开更多
文摘Dissimilar friction stir welding between AZ31-O Mg and 6061-T6 Al alloys was investigated. 3 mm thick plates of aluminum and magnesium were used. Friction stir welding operations were performed at different rotation and travel speeds. The rotation speeds varied from 600 to 1400 r/min, and the travel speed varied from 20 to 60 mm/min. Defect-free weld was obtained with a rotation speed of 1000 r/min and travel speed of 40 mm/min. Metallographic studies showed that the grain size in the stir zone is much finer than that in the base metals. Complex flow pattern was formed in the stir zone. Microhardness measurement revealed an uneven distribution in the stir zone. Tensile test results indicated that the tensile strength of the welded specimen is about 76% of AZ31 Mg alloy and 60% of the 6061 Al alloy in tensile strength. SEM fracture surface image of the welded specimen indicated that the welded specimen failed through brittle-mode fracture.
基金conducted as the project number 298113 supported by Isfahan University of Medical Sciences.
文摘Background Recently,beneficial effects of probiotics and/or prebiotics on cardio-metabolic risk factors in adults have been shown.However,existing evidence has not been fully established for pediatric age groups.This study aimed to assess the effect of synbiotic on anthropometric indices and body composition in overweight or obese children and adolescents.Methods This randomized double-blind,placebo-controlled trial was conducted among 60 participants aged 8-18 years with a body mass index(BMI)equal to or higher than the 85th percentile.Participants were randomly divided into two groups that received either a synbiotic capsule containing 6x109 colony forming units(CFU)Lactobacillus coagulans SC-208,6 x 109 CFU Lactobacillus indicus HU36 and fructooligosaccharide as a prebiotic(n=30)or a placebo(n=30)twice a day for eight weeks.Anthropometric indices and body composition were measured at baseline and after the intervention.Results The mean(standard deviation,SD)age was 11.07(2.00)years and 11.23(2.37)years for the placebo and synbiotic groups,respectively(P=0.770).The waist-height ratio(WHtR)decreased significantly at the end of the intervention in comparison with baseline in the synbiotic group(0.54±0.05 vs.0.55±0.05,P=0.05).No significant changes were dem-onstrated in other anthropometric indices or body composition between groups.Conclusions Synbiotic supplementation might be associated with a reduction in WHtR.There were no significant changes in other anthropometric indices or body composition.
