The characteristics of mechanical transportation and pneumatic transportation in sinter plant were introduced. Taking a Brazilian project as an example,we come to an conclusion by technical economical comparison that ...The characteristics of mechanical transportation and pneumatic transportation in sinter plant were introduced. Taking a Brazilian project as an example,we come to an conclusion by technical economical comparison that pneumatic transportation has more advantages than mechanical transportation,and it should be promoted in sinter plant.展开更多
Impact bruise damage and quality of‘Gim Ju’guava were investigated for different drop heights and number of drops using fractal image analysis.For the impact test,a stainless-steel metal ball(250 g)was dropped on fr...Impact bruise damage and quality of‘Gim Ju’guava were investigated for different drop heights and number of drops using fractal image analysis.For the impact test,a stainless-steel metal ball(250 g)was dropped on fruit from three drop heights(0,0.3,0.6 m)either once or five times.Fruit quality was evaluated for impact energy,bruise area(BA),bruise volume(BV),bruise susceptibility,bruise score and pulp color(L*,a*,b*and C values).The fractal dimension(FD)value using fractal image analysis was analyzed at the bruise region.Results showed that five drops(0.3 m)with a high impact energy(3678.75 J)and a single drop(0.6 m)with a low impact energy(1471.50 J)exhibited no significant in BA,BV,bruise score as well as all color values(L*,a*,b*and C).While the FD value of a single drop from 0.6 m had a higher FD value than that of five drops from 0.3 m.It is indicated that FD exhibited a better performance to classify impact bruising level of guava than BA,BV and color parameters.The FD value gradually decreased with increase of storage time and bruise severity.The correlation coefficient(r)values of FD(r=−0.794 and−0.745)between BA and BV were more significant than those L*(r=−0.660 and−0.615)and a*(r=0.579 and 0.473).The coefficient of determination(R^(2))of the polynomial equation in bruised fruit(R^(2)=0.85 to 0.99)was greater than the control(no bruise)(R^(2)=0.80).A higher R^(2)val(0.88 and 0.92)was exhibited at five drops.Interestingly,FD analysis showed greater potential than color measurement to assess bruise impact damage in guava.展开更多
As our transportation infrastructure ages,its deterioration is becoming a growing concern.Rapid and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadwa...As our transportation infrastructure ages,its deterioration is becoming a growing concern.Rapid and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadway bridges.In this work,laser-based additive manufacturing(AM)was developed for the repair of damaged beams in steel bridges.A corroded structural beam of low-carbon A36 steel was selected for this case study and 316L stainless steel was used for repair due to its excellent mechanical properties and corrosion resistance.Simulated repair experiments were performed on specimens extracted from the beam,and prepared with various groove shapes(Rectangular,Trapezoidal,and U-shaped).More in-depth parametric and microstructural studies were carried out with a series of U-shaped specimens repaired with the linear laser input energy varied from 19.5 to 30.0 J mm–1.The tensile properties of the repaired specimens and interface structures were also investigated in detail.It was found that the repaired specimens had a slightly higher tensile strength despite a reduction in tensile elongation compared to the A36 steel base metal.The influence of interfacial microstructure and heterogeneity on the mechanical properties of the repaired specimens was discussed.Our work suggests the promising potential to employ AM for structural repair and provides fundamental insights into processing-structure-property relationships in laser AM-repaired materials.展开更多
文摘The characteristics of mechanical transportation and pneumatic transportation in sinter plant were introduced. Taking a Brazilian project as an example,we come to an conclusion by technical economical comparison that pneumatic transportation has more advantages than mechanical transportation,and it should be promoted in sinter plant.
文摘Impact bruise damage and quality of‘Gim Ju’guava were investigated for different drop heights and number of drops using fractal image analysis.For the impact test,a stainless-steel metal ball(250 g)was dropped on fruit from three drop heights(0,0.3,0.6 m)either once or five times.Fruit quality was evaluated for impact energy,bruise area(BA),bruise volume(BV),bruise susceptibility,bruise score and pulp color(L*,a*,b*and C values).The fractal dimension(FD)value using fractal image analysis was analyzed at the bruise region.Results showed that five drops(0.3 m)with a high impact energy(3678.75 J)and a single drop(0.6 m)with a low impact energy(1471.50 J)exhibited no significant in BA,BV,bruise score as well as all color values(L*,a*,b*and C).While the FD value of a single drop from 0.6 m had a higher FD value than that of five drops from 0.3 m.It is indicated that FD exhibited a better performance to classify impact bruising level of guava than BA,BV and color parameters.The FD value gradually decreased with increase of storage time and bruise severity.The correlation coefficient(r)values of FD(r=−0.794 and−0.745)between BA and BV were more significant than those L*(r=−0.660 and−0.615)and a*(r=0.579 and 0.473).The coefficient of determination(R^(2))of the polynomial equation in bruised fruit(R^(2)=0.85 to 0.99)was greater than the control(no bruise)(R^(2)=0.80).A higher R^(2)val(0.88 and 0.92)was exhibited at five drops.Interestingly,FD analysis showed greater potential than color measurement to assess bruise impact damage in guava.
基金This study was undertaken as part of the Massachusetts Department of Transportation Research Program with funding from the Federal Highway Administration State Planning and Research funds,under the Project(ISA:INTF0OXO_(2)O_(2)0A0110756)W.C.is grateful for support from the US National Science Foundation(No.DMR-2004429)This research used resources of the Advanced Pho-ton Source,a U.S.Department of Energy(DOE)Office of Science user facility operated for the DOE Office of Science by Argonne Na-tional Laboratory(Contract No.DE-AC02-06CH11357).
文摘As our transportation infrastructure ages,its deterioration is becoming a growing concern.Rapid and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadway bridges.In this work,laser-based additive manufacturing(AM)was developed for the repair of damaged beams in steel bridges.A corroded structural beam of low-carbon A36 steel was selected for this case study and 316L stainless steel was used for repair due to its excellent mechanical properties and corrosion resistance.Simulated repair experiments were performed on specimens extracted from the beam,and prepared with various groove shapes(Rectangular,Trapezoidal,and U-shaped).More in-depth parametric and microstructural studies were carried out with a series of U-shaped specimens repaired with the linear laser input energy varied from 19.5 to 30.0 J mm–1.The tensile properties of the repaired specimens and interface structures were also investigated in detail.It was found that the repaired specimens had a slightly higher tensile strength despite a reduction in tensile elongation compared to the A36 steel base metal.The influence of interfacial microstructure and heterogeneity on the mechanical properties of the repaired specimens was discussed.Our work suggests the promising potential to employ AM for structural repair and provides fundamental insights into processing-structure-property relationships in laser AM-repaired materials.
