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Volume 29 (2004)
- Issue 6 Pages 324-
- Issue 5 Pages 250-
- Issue 4 Pages 194-
- Issue 3 Pages 140-
- Issue 2 Pages 80-
- Issue 1 Pages 2-
Volume 29, Issue 6
Displaying 1-13 of 13 articles from this issue
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Saburo Harada2004 Volume 29 Issue 6 Pages 324-327
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSApplications of membrane technologies to food processing have been expanding slowly but steadily. There are many cases in which valuable substances contained in waste water from food processing steps are recovered and utilized effectively by membrane technologies. The applications of sterile filtration for upgrading food quality are increasing and membrane technologies are also actively used for the development of functional new foods.View full abstractDownload PDF (602K) -
Akinori Shigematsu2004 Volume 29 Issue 6 Pages 328-332
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe breakthrough of Microfiltration (MF) technology in the dairy industry came at the end of the 1980s with two developments. The first was new ceramic membrane with a highly permeable support. The second was a unique Uniform Transmembrane Pressure (UTP) system created by a co-current circulation of the MF permeate to the feed. The applications of MF developed since then in the dairy industry are as follows; removal of bacteria and spore from skim milk, whey defatting, and micellar casein enrichment of the cheese milk. In addition, many other applications are being investigated in the research institutes; separation of β-casein, globular milk fat fractionation, and selective separation of bacteria. Recent developments in membrane manufacturing technology allow omitting of the MF recirculation loop, or a decimal reduction of 3.6 or more with no significant reduction in performance efficiency, or both.
In this paper, we briefly introduce the outline of the UTP concept and dairy applications of microfiltration technology at present.View full abstractDownload PDF (821K) -
Kiro Hayakawa2004 Volume 29 Issue 6 Pages 333-338
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSMembrane technology in the vegetable and fruit processing has been applied for concentration using RO membrane and for clarification using UF or MF membrane.
Recent technological advances related to the development of new membrane system, advanced separation and recovery of valuable components, improvement quality, saving energy consumption and reduction of environmental negative impact, have expanded the range of membrane separation.
We have developed two new membrane systems. One is RO concentration system for material including the solid. Conventional RO system has been used for only juice concentration including the solid below 0.5mm particle size, by this new RO system, it is possible to concentrate liquid including 0.5mm-10mm particle size solid.
Another is electrodialysis system for reduction of nitrate in a green vegetable, the characteristic of this system is to be operated under high concentration (Brix20), low velocity and low temperature condition.View full abstractDownload PDF (1094K) -
Mitsuru Higa2004 Volume 29 Issue 6 Pages 339-344
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSIonic transport phenomena in a diffusion dialysis system consisting of a charged membrane and mixed electrolyte solutions can be predicted in terms of a simulation method based on the Nernst-Planck equation of ionic flux and the Donnan equation. The simulations show that a charged membrane can control the transport modes of just multi-valent ions in two ways : downhill (the transport along their own concentration gradient in a system) and uphill (the transport against their own concentration gradient), by changing its charge density. Hence, a charged membrane, whose charge density changes in response to external stimuli can control the transport modes of the specific ions by changing the stimuli. Permeation experiment in a dialysis system consisting of mixed KCl and CaCl2 solutions and a temperature-responsive membrane that has a charge density response to temperature changes shows that the membrane can control the transport modes of just Ca2+ ions in two ways : downhill and uphill, in response to temperature changes.View full abstractDownload PDF (675K) -
Hidetoshi Matsumoto2004 Volume 29 Issue 6 Pages 345-349
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSSurface electrochemical property, which is represented as ζ-potential or surface charge density, is a key parameter in membrane science. Charge on membrane surface plays an important role in the separation performance and fouling tendency. Electrokinetic measurements are a straightforward and powerful method to provide information about charge characteristics at the membrane-solution interface. This method also has higher sensitivity than the spectroscopic surface analysis methods (e.g., SEM, EDX, and FT-IR). Therefore, the electrokinetic characterization can be widely used for not only separation membrane surfaces and biocompatible interfaces, but also nano-engineered surfaces. Here, we presented general remarks on electrokinetic characterization of charged membranes based on streaming potential measurements, focusing on amphoteric charged membranes.View full abstractDownload PDF (771K) -
Koji Asami2004 Volume 29 Issue 6 Pages 350-352
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSIn this article I describe the application of dielectric spectroscopy to charged membranes in aqueous media. Possible mechanisms, such as interfacial polarization and counterion polarization, are discussed for dielectric relaxation in the membrane systems.View full abstractDownload PDF (543K) -
Wataru Shinoda2004 Volume 29 Issue 6 Pages 353-358
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA slight structural change in lipid molecules sometimes produces dramatic changes in the membrane properties such as structural stability and solute permeability. For example, archaeal lipids bearing ether-linked, highly branched hydrophobic chains form stabile bilayers with low permeability of ionic and nonionic solutes. Nowadays, it is possible to investigate the alteration of the membrane properties induced by a variation of the molecular structure of lipids by using molecular dynamics (MD) simulations. The approach will open a way to design a novel lipid, which should form a membrane with desirable physical properties on the purpose, based upon molecular simulations. In this review, we will introduce a few of our recent MD studies on the effect of chain branching and ether-linkage on the membrane properties.View full abstractDownload PDF (1035K) -
Minoru Sakurai2004 Volume 29 Issue 6 Pages 359-362
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSHere, we describe the results of computer simulations for some retinal proteins. In our simulations, the membrane environments surrounding the proteins were treated at three different levels of approximation : 1) neglect of the membrane (protein placed in vacuo), 2) low dielectric continuum, and 3) more realistic model that explicitly takes into account all the atoms of phospholipids and water molecules. Under approximation 1), we calculated the excitation energies of several retinal proteins using a QM/MM-CI theory recently developed by us. There was found a good correlation between the calculated and observed data. Under approximation 2), the binding affinity between phoborhodopsin and transducer protein (HtrII) was estimated using linear-scaling molecular orbital calculations. According to our calculations, the tendency of the observed binding affinity, including the effect of mutation at Tyr199, was successfully reproduced if the dielectric constant of the membrane region is assumed to be about 4. Finally, we discuss the outlook for molecular dynamic simulations based on approximation 3).View full abstractDownload PDF (493K) -
Yoshitada Morikawa2004 Volume 29 Issue 6 Pages 363-366
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDue to stability and high ordering, self-assembled monolayers (SAMs) have, enormous potential for various applications such as coating material, sensors, non-linear optical materials, catalysis and so on. Among them, alkanethiols (CH3 (CH2) nSH) and dialkyl disulfides (CH3 (CH2) nS-S (CH2) nCH3) on Au (111) surfaces have been the most widely studied SAM systems because they are simple and easy to prepare even in air or in solution, as well as in vacuum. However, the adsorption states of these molecules, especially the interaction between the S head groups and the Au substrates, which partly determines the structure and its evolution of SAM, are still a matter of intense debate. In this work, we studied the adsorption state of dimethyl disulfide (DMDS, CH3SSCH3) and methylthiolate, the simplest dialkyl disulfide and thiolate, on the Au (111) surface using density functional theory (DFT) with repeated slab models. We find an excellent agreement of the computed and the experimental HREEL spectra, thus providing very strong support for our results.View full abstractDownload PDF (868K) -
Concentration of Water-soluble Materials Using Osmotic Pressure of the Water Phase in a W/O EmulsionMasato Kukizaki, Tadao Nakashima, Masataka Shimizu2004 Volume 29 Issue 6 Pages 367-376
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSA new process for concentrating water-soluble materials was developed using osmotic pressure of the water phase in a W/O emulsion, and was applied to the concentration of an amino acid. Two kinds of monodispersed W/O emulsions; a 0.005 mol·kg-1 monosodium glutaminate aqueous solution, and a 4.50 mol·kg-1 sodium chloride solution with high osmotic pressure as the dispersed phase, were prepared by the membrane emulsification technique using a hydrophobic porous glass membrane. The two emulsions were mixed and stirred. As a consequence, osmotic pressure as the driving force led to the shrinkage of the monosodium glutaminate-containing water droplets and the swelling of the sodium chloride-containing water droplets. The droplets were then separated by a hydrophobic porous glass membrane with a mean pore size in-between the particle sizes of the shrunken and the swollen droplets. Afterwards, the separated emulsion was permeated through a porous glass membrane with a mean pore size larger than the size of the containing particles. The emulsion was demulsified, after which a 25X concentrated monosodium glutaminate solution was obtained. Calculated value based on the theoretical transport of water through the oil phase with osmotic pressure as the driving force showed good agreement with measured value.View full abstractDownload PDF (1341K) -
Takayuki Sakiyama, Takashi Aoki, Masakazu Yoshikawa2004 Volume 29 Issue 6 Pages 377-383
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSNovel liquid membranes were constructed by using ABA triblock copolymer polyoxyethylene-block-polydimethylsiloxane-block-polyoxyethylene as a membrane matrix. The block copolymer was prepared from methoxy polyoxyethylene and bifunctional polydimethylsiloxane adopting 4, 4'-diphenylmethane diisocyanate as a linker by one pot synthesis. The ABA triblock copolymer gave a relatively stable liquid membrane. The liquid membrane containing dibenzo-18-crown-6 (DB18C6) as a model transporter showed transport ability of NaCl. The flux of NaCl through the present liquid membrane with 5.0wt.% DB18C6 was 1.3×10-5mol cm-2 h-1.View full abstractDownload PDF (1056K) -
Masakazu Yoshikawa, Kensuke Kawamura, Akinori Ejima, Takashi Aoki, Kun ...2004 Volume 29 Issue 6 Pages 384-387
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe vapor permeation of aqueous 2-PrOH mixtures was investigated by using the thermostable natural polymer, water soluble protein from thermophile Geobacillus thermodenificans DSM465, as one of the membrane components in a polymer blend. The cultured protein/Torlon poly (amide-imide) blended membranes preferentially permeated H2O from aqueous 2-PrOH by vapor permeation. Membranes containing the proteins from G. thermodenificans DSM465 were applied to the dehydration of aqueous 2-PrOH.View full abstractDownload PDF (798K) -
Kiyokazu Takemura, Naoki Ohkuma, Makoto Oonishi, Kazuhiko Noto2004 Volume 29 Issue 6 Pages 388-391
Published: November 01, 2004
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSIntegrated flat sheet membrane element was newly developed for submerged membrane bio-reactor (MBR) system. Since 1998 through 2000, a large pilot research on the applicability of the MBR system for treatment of municipal wastewater was executed under co-operation between Japan Sewage Works Agency and Hitachi Plant. The positive results that came from the research would lead to full-scale installation of the MBR system in the field of municipal WWTP.
Through the high effluent quality achieved using the MBR system the direct re-use for landscape irrigation or water related amenity will become possible. In addition, the MBR system showed good performance on removing pathogens such as infectious viruses and was expected for decreasing the risk of infection on the water re-use of treated municipal wastewater.View full abstractDownload PDF (713K)
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