The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

Minh H Nguyen - One of the best experts on this subject based on the ideXlab platform.

  • mass and heat transfer analysis in fructose concentration by osmotic distillation process using Hollow Fibre Module
    Journal of Food Engineering, 2007
    Co-Authors: R Thanedgunbaworn, Ratana Jiraratananon, Minh H Nguyen
    Abstract:

    Abstract Osmotic distillation process was carried out on a Hollow Fibre membrane Module using fructose solutions and clarified grape juice as feeds. The influence of operating parameters such as feed and brine flow velocities, feed concentration, and temperature, on the osmotic distillation flux was studied. For the experimental conditions employed, the water flux varied from 0.58 kg m −2  h −1 to 2.02 kg m −2  h −1 . Temperature and feed concentration had significant effect on flux. On the contrary, feed and brine velocities had little effect on flux. The increase of feed and brine velocities or change of the hydrodynamic conditions also enhanced flux. The concentration polarization at high flow velocities can be neglected. In this work, the value of temperature polarization was small and the polarization coefficient Θ was estimated. It was found that temperature polarization reduced the driving force for mass transfer approximately 5–6%. However, this phenomenon affected the transport resistance of the system. The concentration and temperature polarization can be reduced by operating the process at high Reynolds number and low temperature. The transport resistance was affected by changing of operating condition such as feed velocity and temperature. The major transport resistance of the process was in the membrane.

  • a laboratory study on glucose concentration by osmotic distillation in Hollow Fibre Module
    Journal of Food Engineering, 2004
    Co-Authors: Minh H Nguyen, Joachim Muller
    Abstract:

    Abstract This research project investigates the concentration of glucose solutions by osmotic distillation (OD) process in Modules using Hollow Fibres PP375, PV375 and PV660 supplied by Memcor Australia (South Windsor, NSW, Australia). Laboratory scale OD systems using Hollow Fibre Modules were designed, constructed, and successfully operated at the University of Western Sydney, Hawkesbury campus, Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux rate. Under the experimental conditions the obtained flux ranged from 1.67 to 4.73 kg m −2  h −1 for PV375, and 1.00 to 2.87 kg m −2  h −1 for PV660.

Joachim Muller - One of the best experts on this subject based on the ideXlab platform.

  • a laboratory study on glucose concentration by osmotic distillation in Hollow Fibre Module
    Journal of Food Engineering, 2004
    Co-Authors: Minh H Nguyen, Joachim Muller
    Abstract:

    Abstract This research project investigates the concentration of glucose solutions by osmotic distillation (OD) process in Modules using Hollow Fibres PP375, PV375 and PV660 supplied by Memcor Australia (South Windsor, NSW, Australia). Laboratory scale OD systems using Hollow Fibre Modules were designed, constructed, and successfully operated at the University of Western Sydney, Hawkesbury campus, Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux rate. Under the experimental conditions the obtained flux ranged from 1.67 to 4.73 kg m −2  h −1 for PV375, and 1.00 to 2.87 kg m −2  h −1 for PV660.

C. Cabassud - One of the best experts on this subject based on the ideXlab platform.

  • Air sparging backwash in ultrafiltration Hollow Fibres for drinking water production
    Water Science & Technology: Water Supply, 2003
    Co-Authors: C. Guigui, M. Mougenot, C. Cabassud
    Abstract:

    Air sparging Was applied to improve backwash efficiency for an ultrafiltration inside/out Hollow-Fibre Module operating in dead-end mode. Air was injected into the retentate side only during the backwash period. The filtration experiments were performed on a semi-industrial scale pilot using a clay suspension as a model of surface waters. The backwash procedure consisted of two steps: in a first step (phase A), air was added to the feed water inside the Fibre lumen at the bottom of the Module. In a second step (phase B), cleaned water backwash was performed. Different air velocities were used and the kinetics of particle removal were studied with turbidity measurements of backwash waters. The experimental results showed that using an air-fluid mixing allows one to increase the quantity of particles removed from the Hollow Fibres. For the phase A, the removed mass is higher when the air velocity and duration of air injection increased. But, even at very low air velocity (0.08 m/s), a high backwash efficiency was observed. Experiments with filtration/air-sparging backwash cycles concluded that using air-fluid mixing in the backwash sequence allowed prevention of long-term fouling and reduced the rate of fouling during the filtration period.

  • Vacuum membrane distillation for seawater desalination: could it compete with reverse osmosis?
    Water Science & Technology: Water Supply, 2003
    Co-Authors: David Wirth, C. Cabassud
    Abstract:

    This work addresses the potentialities of vacuum membrane distillation (VMD) using Hollow Fibre membranes for seawater desalination. Experiments were carried out with a synthetic salty water containing a concentration of NaCl from 0 up to 300 g/L. A Microza (Pall) Hollow Fibre Module was used. Experimental results show that, for this Module, concentration polarisation and heat transfer limitations are not significant and do not modify the permeate flux. This is a great advantage over reverse osmosis (RO). Energy consumption was then studied using computations based on modelling. Two different industrial plants were considered: the first one consisted of Hollow Fibre Modules arranged in series and operated in a single-pass. The second one was designed for a discontinuous operation using a circulation loop. Computations clearly show the interest (low energy consumption) of VMD for seawater desalination in comparison with RO.

  • Water desalination using membrane distillation: comparison between inside/out and outside/in permeation
    Desalination, 2002
    Co-Authors: David Wirth, C. Cabassud
    Abstract:

    This work focuses on vacuum membrane distillation (VMD) for seawater desalination. The aim of the work was to compare two Hollow Fibre Module configurations (inside/out and outside/in). Experiments were carried out with pure water and with 15 g/L up to 300 g/L NaCl solutions and for two different material and structure of Fibres. Pure water permeability and global heat transfer coefficient were compared for the two configurations. The influence of hydrodynamics on global heat and mass transfer coefficients is discussed.

Yuichiro Ueda - One of the best experts on this subject based on the ideXlab platform.

  • Pharmacokinetic Considerations in Development of a Bioartificial Liver
    Clinical Pharmacokinectics, 2012
    Co-Authors: Hiroo Iwata, Yuichiro Ueda
    Abstract:

    We consider the pharmacokinetics of bioartificial livers (BALs) prepared using a Hollow Fibre Module with respect to two key functions, detoxification and plasma protein supply, and present the results in a simple form. We then discuss the advantages and disadvantages of BAL therapy in comparison with the non-biological therapies of haemodialysis and plasma exchange.

  • Pharmacokinetic Considerations in Development of a Bioartificial Liver
    Clinical Pharmacokinetics, 2004
    Co-Authors: Hiroo Iwata, Yuichiro Ueda
    Abstract:

    We consider the pharmacokinetics of bioartificial livers (BALs) prepared using a Hollow Fibre Module with respect to two key functions, detoxification and plasma protein supply, and present the results in a simple form. We then discuss the advantages and disadvantages of BAL therapy in comparison with the non-biological therapies of haemodialysis and plasma exchange. Nitrogenous and other potentially toxic compounds, such as ammonia, mercaptans, short-chain fatty acids and γ-aminobutyric acid, are produced in the bowels and accumulate in the systemic blood because of impaired elimination by the ailing liver. Adrenal and gonadal steroids, including corticosteroids, estrogens, progestins and androgens, are biosynthesised, and high concentrations of these hormones become harmful. All these endogenously produced toxins require effective metabolism. In haemodialysis, toxins that permeate through the Hollow Fibre membrane are rapidly removed by the dialysate flow, and their concentrations decrease to almost zero. In a BAL bioreactor, the toxins are slowly metabolised by hepatocytes in the Hollow Fibres, and decreased to concentrations that are inversely proportional to the number of hepatocytes in the BAL, even after a long-term assist. It is difficult to rationalise the clinical usage of BAL systems containing small amounts of hepatocytes (70–100g) to remove the toxins. Concentrations of plasma proteins in a patient after long-term BAL treatment are proportional to the number of hepatocytes in the device. BAL reactors prepared using porcine hepatocytes supply porcine proteins, not human proteins, to the recipient. Plasma exchange increases protein concentrations much more effectively than BAL as long as a sufficient amount of plasma is available. The blood inflow rate to the liver is about 1500 mL/min in a normal adult. On the other hand, blood draw rates to a BAL system are restricted to the range of 100–300 mL/min. Toxins that are rapidly cleared by the liver (for example, the ammonia clearance of the normal human liver is several hundred mL/min) cannot be effectively eliminated from the systemic blood by BAL systems currently under clinical evaluation. Hepatocytes are the only elements in a BAL reactor that can metabolise toxins and synthesise proteins, and thus BAL performance increases with the increasing number of hepatocytes in the bioreactor. The human liver weighs about 1500g and contains about 80% hepatocytes, i.e. about 1200g of hepatocytes. The blood flow through the liver is about 1500 mL/min in a normal adult. To effectively replace liver functions would require a BAL reactor containing the functional equivalent of several hundreds of grams of human hepatocytes with an extracorporeal perfusion rate of more than 1000 mL/min. At this point, only orthotopic liver transplantation can meet these criteria.

Muller Joachim - One of the best experts on this subject based on the ideXlab platform.

  • characterisation of the polarisations in osmotic distillation of glucose solutions in Hollow Fibre Module
    Journal of Food Engineering, 2005
    Co-Authors: H M Nguyen, Muller Joachim
    Abstract:

    Abstract This paper quantifies the characteristics of concentration and temperature polarisations in osmotic distillation of glucose solutions in Hollow Fibre Module using PVDF Fibres, being PV375 and PV660 for low and high feed concentration range respectively. Concentration polarisation on the brine side was found to be more severe than on the feed side with concentration differences being up to 3.17% on the brine side and 1.43% on the feed side. Temperature polarisation, however, was more intensive on the brine side for lower feed concentration range, but less intensive when dealing with higher feed concentration. Under the reported experimental conditions, the temperature differences across the membrane were up to 1.53 °C in Module PV375, and 1.33 °C in Module PV660. Overall, concentration and temperature polarisations were found to contribute up to 18% to OD flux reduction.