Several applications such as liquid-liquid extraction in micro-fluidic devices are concerned with the flow of two immiscible liquid phases. The commonly observed flow regimes in these systems are slug-flow and stratif...Several applications such as liquid-liquid extraction in micro-fluidic devices are concerned with the flow of two immiscible liquid phases. The commonly observed flow regimes in these systems are slug-flow and stratified flow. The latter regime in micro-channels has the inherent advantage that separation of the two liquids at the exit is efficient. Recently extraction in a stratified counter-current flow has been studied experimentally and it has been shown to be more efficient than co-current flow. An analytical as well as a numerical method to determine the steady-state solution of the corresponding convection-diffusion equation for the two flow-fields is presented. It is shown that the counter-current process is superior to the co-current process for the same set of parameters and operating conditions. A simplified model is proposed to analyse the process when diffusion in the transverse direction is not rate limiting. Different approaches to determining mass transfer coefficient are compared. The concept of log mean temperature difference used in design of heat exchangers is extended to describe mass transfer in the system.展开更多
AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy ...AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy （TAO）. METHODS： Sixty-two orbits from 62 TAO patients were randomly assigned to OD or OD＋HCSE at 1：1 ratio （31 received OD alone, 31 received OD ＋HCSE）. Forty-two orbits from 21 healthy subjects were used as controls. Complete ophthalmic examination and color Doppler flow imaging （CDFI） were performed before surgery and 3mo post-surgery on all 62 orbits from the TAO patients. CDFI were also performed on the 42 control orbits, The effect of OD ＋HCSE and OD alone on TAO orbits was compared on several endpoints, including superior ophthalmic vein blood flow （SOVBF） parameters, subjective assessment, soft tissue involvement, lid retraction, diplopia, eye movement restriction, degree of exophthalmos, and intraocular pressure. The control orbits were used as reference for the SOVBF parameters. RESULTS： OD surgery with or without HCSE improved SOVBF, symptoms and soft tissue involvement, decreased degree of exophthalmos and intraocular pressure in orbits of TAO patients. The OD ＋HCSE combination led to significantly better improvement of SOVBF than OD alone. The differences between the reductions of SOVBF in the two groups are 1.26 cmls in max-volecity and 0.52 cm/s in min-voiecity （P〈0.0001）. CONCLUSION： SOVBF is significantly reduced in the orbits affected with TAO, indicating that congestion may be an important factor contributing to TAO pathogenesis. OD surgery improves the SOVBF, and combination of HCSE medication and OD surgery further improved venous return than OD surgery alone.展开更多
文摘Several applications such as liquid-liquid extraction in micro-fluidic devices are concerned with the flow of two immiscible liquid phases. The commonly observed flow regimes in these systems are slug-flow and stratified flow. The latter regime in micro-channels has the inherent advantage that separation of the two liquids at the exit is efficient. Recently extraction in a stratified counter-current flow has been studied experimentally and it has been shown to be more efficient than co-current flow. An analytical as well as a numerical method to determine the steady-state solution of the corresponding convection-diffusion equation for the two flow-fields is presented. It is shown that the counter-current process is superior to the co-current process for the same set of parameters and operating conditions. A simplified model is proposed to analyse the process when diffusion in the transverse direction is not rate limiting. Different approaches to determining mass transfer coefficient are compared. The concept of log mean temperature difference used in design of heat exchangers is extended to describe mass transfer in the system.
文摘AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy （TAO）. METHODS： Sixty-two orbits from 62 TAO patients were randomly assigned to OD or OD＋HCSE at 1：1 ratio （31 received OD alone, 31 received OD ＋HCSE）. Forty-two orbits from 21 healthy subjects were used as controls. Complete ophthalmic examination and color Doppler flow imaging （CDFI） were performed before surgery and 3mo post-surgery on all 62 orbits from the TAO patients. CDFI were also performed on the 42 control orbits, The effect of OD ＋HCSE and OD alone on TAO orbits was compared on several endpoints, including superior ophthalmic vein blood flow （SOVBF） parameters, subjective assessment, soft tissue involvement, lid retraction, diplopia, eye movement restriction, degree of exophthalmos, and intraocular pressure. The control orbits were used as reference for the SOVBF parameters. RESULTS： OD surgery with or without HCSE improved SOVBF, symptoms and soft tissue involvement, decreased degree of exophthalmos and intraocular pressure in orbits of TAO patients. The OD ＋HCSE combination led to significantly better improvement of SOVBF than OD alone. The differences between the reductions of SOVBF in the two groups are 1.26 cmls in max-volecity and 0.52 cm/s in min-voiecity （P〈0.0001）. CONCLUSION： SOVBF is significantly reduced in the orbits affected with TAO, indicating that congestion may be an important factor contributing to TAO pathogenesis. OD surgery improves the SOVBF, and combination of HCSE medication and OD surgery further improved venous return than OD surgery alone.
