-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-...-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula.展开更多
This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units....This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units. The capsaicin is mixed with a silicon dioxide and then solubilized into a free-flowing homogeneous liquid oleoresin composition by adding a solvent to increase solubility and facilitate mixing. The oleoresin capsaicin liquid solution is mixed with a suitable corrosion resistant epoxy resin, which is then mixed with a hardening catalyst and applied to the surface to be treated.展开更多
Hydrokinetic energy is a promising technology to harness predictable renewable energy from free-flowing water,tides and ocean currents.Many studies have been conducted by researchers and engineers to find out ways to ...Hydrokinetic energy is a promising technology to harness predictable renewable energy from free-flowing water,tides and ocean currents.Many studies have been conducted by researchers and engineers to find out ways to enhance the performance of the hydrokinetic turbine.The current paper reports the experimental study of using hydrophobic coating as an alternative way to improve the performance of hydrokinetic turbine.A hydrophobic coating can lower the friction drag of a surface that is in contact with liquid.For hydrokinetic turbine blade,reduction in friction drag may allow a blade section to have a better lift/drag ratio and have its efficiency improved.In this study,a formula to predict the pattern of drag reduction over a hydrophobic surface has been derived.Two hydrophobic coatings were applied on NACA 63418 hydrofoils and their performances were tested.It was found that NACA 63418 hydrofoil with the hydrophobic coatings had its drag reduced by an average of 3%−4.0%.When the coatings were applied on a 350 mm diameter three-bladed turbine,the maximum increment of rotational speed of the turbine was found to be 2.5%.The performance of the two coatings against marine fouling was also investigated.The weight of plate with and without the coatings increased by 10%and 100%,respectively.展开更多
Marine biofouling is a global problem that is detrimental to both moving ships and static underwater devices.Marine microorganisms tend to attach to any unprotected surface and grow into biofilm,which can be hardly re...Marine biofouling is a global problem that is detrimental to both moving ships and static underwater devices.Marine microorganisms tend to attach to any unprotected surface and grow into biofilm,which can be hardly removed even under high shear flow condition[1].With the long-term accumulation of marine organisms,ships suffer significantly from the increase on the net weight as well as the drag when cruising.Increased drag causes fuel power penalties of up to86%at cruising speed;it is notable even a very thin layer展开更多
文摘-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula.
文摘This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units. The capsaicin is mixed with a silicon dioxide and then solubilized into a free-flowing homogeneous liquid oleoresin composition by adding a solvent to increase solubility and facilitate mixing. The oleoresin capsaicin liquid solution is mixed with a suitable corrosion resistant epoxy resin, which is then mixed with a hardening catalyst and applied to the surface to be treated.
基金financially supported by the Natural Science Foundation of Hunan Province(Grant No.2019JJ50644).
文摘Hydrokinetic energy is a promising technology to harness predictable renewable energy from free-flowing water,tides and ocean currents.Many studies have been conducted by researchers and engineers to find out ways to enhance the performance of the hydrokinetic turbine.The current paper reports the experimental study of using hydrophobic coating as an alternative way to improve the performance of hydrokinetic turbine.A hydrophobic coating can lower the friction drag of a surface that is in contact with liquid.For hydrokinetic turbine blade,reduction in friction drag may allow a blade section to have a better lift/drag ratio and have its efficiency improved.In this study,a formula to predict the pattern of drag reduction over a hydrophobic surface has been derived.Two hydrophobic coatings were applied on NACA 63418 hydrofoils and their performances were tested.It was found that NACA 63418 hydrofoil with the hydrophobic coatings had its drag reduced by an average of 3%−4.0%.When the coatings were applied on a 350 mm diameter three-bladed turbine,the maximum increment of rotational speed of the turbine was found to be 2.5%.The performance of the two coatings against marine fouling was also investigated.The weight of plate with and without the coatings increased by 10%and 100%,respectively.
基金supported by the U.S.National Science Foundation(Grant No.DMR-1410853)the faculty start-up fund at Wayne State University,Chemical Engineering and Materials Science
文摘Marine biofouling is a global problem that is detrimental to both moving ships and static underwater devices.Marine microorganisms tend to attach to any unprotected surface and grow into biofilm,which can be hardly removed even under high shear flow condition[1].With the long-term accumulation of marine organisms,ships suffer significantly from the increase on the net weight as well as the drag when cruising.Increased drag causes fuel power penalties of up to86%at cruising speed;it is notable even a very thin layer
