Almost half of the oceanic water columns exhibit double-diffusion. The importance of double-diffusion in global oceans’ salt and heat fluxes, water-mass formation and mixing, and circulation is increasingly recognize...Almost half of the oceanic water columns exhibit double-diffusion. The importance of double-diffusion in global oceans’ salt and heat fluxes, water-mass formation and mixing, and circulation is increasingly recognized. However, such an important physical process in the ocean has not been well studied. One of the reasons is the difficulty of parameterizing and quantifying the processes. The paper presented here attempts to quantify the double-diffusive fluxes of salt and heat in the ocean. Previous qualitative analysis by applying the water-mass Turner angle, mTu, to the North Pacific Intermediate Water (NPIW) layer showed a favorable condition for salt-fingering in the upper NPIW due to the overlying warm/salty water above the cold/fresh NPIW core, and a doubly-stable condition in the lower NPIW where potential temperature decreases with depth while salinity increases, inducing double stratification with respect to both potential temperature and salinity. The present study gives a quantitative estimate of double-diffusive fluxes of salt and heat contributed by salt-fingering in the upper NPIW layer.展开更多
The primary interest to this study was to investigate the effect of milling parameters on the size of hydrophobically modified starch particles, aiming to produce small, uniformly sized modified starch microspheres. O...The primary interest to this study was to investigate the effect of milling parameters on the size of hydrophobically modified starch particles, aiming to produce small, uniformly sized modified starch microspheres. Octie, a commercial product originated from cornstarch modified using Octenyl Succinate Anhydride （OSA）, was dispersed （3 wt%） using different media （water or ethanol） and subsequently wet-milled using a beads mill with zirconium beads at a rotation of 6,000 rpm up to 30 min. It was found that milling Octie in water dispersion for 3 min resulted in the smallest mean particle size （2.04 i 0.91 ktm）, compared to unmilled modified starch granules （15.2 ~ 6.0 lam）. Granular size and morphology changed considerably with further milling. For instance, very dense clusters with variable particle sizes （20.6 ~ 10.0 lam） were obtained after 30 min milling. As depicted by Scanning Electronic Microscopy, a large number of particles were apparently flattened during the milling process rather than broken, forming aggregates. Ultimately, within the range of experimental conditions tested, production of sub-micron modified starch particles was not possible.展开更多
基金a result of my short visit to the Physical Oceanography Laboratory of Ocean University of ChinaQingdao with support from the Foundation for Open Projects of the Key Lab.of Physical Oceanography,the Ministry of Education,China(No.200401).
文摘Almost half of the oceanic water columns exhibit double-diffusion. The importance of double-diffusion in global oceans’ salt and heat fluxes, water-mass formation and mixing, and circulation is increasingly recognized. However, such an important physical process in the ocean has not been well studied. One of the reasons is the difficulty of parameterizing and quantifying the processes. The paper presented here attempts to quantify the double-diffusive fluxes of salt and heat in the ocean. Previous qualitative analysis by applying the water-mass Turner angle, mTu, to the North Pacific Intermediate Water (NPIW) layer showed a favorable condition for salt-fingering in the upper NPIW due to the overlying warm/salty water above the cold/fresh NPIW core, and a doubly-stable condition in the lower NPIW where potential temperature decreases with depth while salinity increases, inducing double stratification with respect to both potential temperature and salinity. The present study gives a quantitative estimate of double-diffusive fluxes of salt and heat contributed by salt-fingering in the upper NPIW layer.
文摘The primary interest to this study was to investigate the effect of milling parameters on the size of hydrophobically modified starch particles, aiming to produce small, uniformly sized modified starch microspheres. Octie, a commercial product originated from cornstarch modified using Octenyl Succinate Anhydride （OSA）, was dispersed （3 wt%） using different media （water or ethanol） and subsequently wet-milled using a beads mill with zirconium beads at a rotation of 6,000 rpm up to 30 min. It was found that milling Octie in water dispersion for 3 min resulted in the smallest mean particle size （2.04 i 0.91 ktm）, compared to unmilled modified starch granules （15.2 ~ 6.0 lam）. Granular size and morphology changed considerably with further milling. For instance, very dense clusters with variable particle sizes （20.6 ~ 10.0 lam） were obtained after 30 min milling. As depicted by Scanning Electronic Microscopy, a large number of particles were apparently flattened during the milling process rather than broken, forming aggregates. Ultimately, within the range of experimental conditions tested, production of sub-micron modified starch particles was not possible.
