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Volume 16 (1991)
- Issue 6 Pages 324-
- Issue 5 Pages 258-
- Issue 4 Pages 192-
- Issue 3 Pages 120-
- Issue 2 Pages 56-
- Issue 1 Pages 3-
Volume 16, Issue 4
Displaying 1-7 of 7 articles from this issue
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P. C. Shukla1991 Volume 16 Issue 4 Pages 192-198
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSElectrokinetic studies of different constituents of urine across urinary bladder membranes have been carried out. Attempts have been made to describe role of urinary bladder in flushing action of urine. Since urinary process may be described in terms of electrokinetic phenomena, detailed study of the phenomena may help in understanding various factors responsible for urination. Physical changes involved in the bladder during micturition have also been discussed. Methodology of nonequilibrium thermodynamics has been used to explain the role of different permeants in micturition. Such studies are expected to be of great use in understanding electrophysiology of the bladder.View full abstractDownload PDF (861K) -
Measurement of Molecular Weight Cut-Off Using GPC Analysis Method for Hollow Fiber MembraneHaruhiko Ohya, Yutaka Urayama, Hiroyuki Yamanaka, Youichi Negishi, Kan ...1991 Volume 16 Issue 4 Pages 199-203
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe purpose of this work was to develop a standard analytical technique for determining solute concentrations in a retention characterization of hollow fiber ultrafiltration (UF) membranes. Six commercially available membranes were selected. The solutes used were three polyethylene glycols (PEG) of different average molecular weights of 7500, 20000, and 50000 and four dextrans (DEX) of different average molecular weights of 10000, 38800, 72200, and 539000. The experiments were done under the following conditions : 10-30 kPa of transmembrane pressure, (TMP), 0.22-0.32 m/s linear velocity, (u), and 300-4500 mg/l feed concentration, (C). The solutions with a single molecular weight solute were analyzed by a TOC analyzer, and a GPC analyzer was used for mixed molecular weight solutions.
The molecular weight cut-off characteristics as determined by the GPC analysis method for mixed molecular weight solutions agreed well with the TOC analysis method for single molecular weight solution. In addition, DEX and PEG solutions gave similar results, and concentration _appeared to have a negligible effect.View full abstractDownload PDF (509K) -
Part I. Copolymer Membranes Composed of N-vinyl Pyrrolidone and Alkyl MethacrylatesTsutomu Nakagawa, Yutaka Sugisaki1991 Volume 16 Issue 4 Pages 204-211
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSIn order to clarify the effect of hydrophobic structures on the hydrophilicity of membranes copolymer membranes composed of a hydrophilic monomer and a hydrophobic monomer. 28 copolymer membranes composed of N-vinyl pyrrolidone (NVP) as a hydrophilic monomer and methyl methacrylate (MMA), ethyl methacrylate (EMA) and iso-butyl methacrylate (IBM) were synthesized. For these copolymer membranes the effect of the side chains of methacrylates on the water content and permeability of oxygen dissolved in water, and solutes was investigated.View full abstractDownload PDF (793K) -
Yasuo Kagawa, Shigeo Ohta, Toshiro Hamamoto1991 Volume 16 Issue 4 Pages 212-222
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe energy transduction in biomembranes requires a special supramolecular structure. This structure is needed for converting proton motive energy into ATP synthesis. These biomembranes contain 4 enzyme complexes that are composed of many polypeptides. Here we describe the following 4 phenomena : 1) oligomer formation by self-assembly of the subunits, 2) incorporation of the oligomers into a lipid bilayer, 3) chaperonin-mediated formation of the oligomers and membranes, 4) coordination of the subunit biosyntheses by enhancers and the role of mitochondrial DNA.
Polypeptides translated are assembled into the membrane complexes with or without the help of chaperonins. In the case of thermophilic proteins, the reconstitutability of polypeptides is excellent ; for example, the catalytic portion of ATP synthase, α1 β1 subunit complex, was reconstituted. On the other hand, mesophilic ATP synthase requires chaperonins for its formation. The transcription of mRNAs for these polypeptides is coordinated by special enhancer and silencer. The role of polypeptides encoded by mitochondrial DNA in the molecular assembly was studied with the wild-type and mutant cells.View full abstractDownload PDF (1943K) -
Kenichi Ikeda1991 Volume 16 Issue 4 Pages 223-232
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSImproved thin-film composite low pressure reverse osmosis membrane has been developed. This membrane exhibits high salt and TOC rejection and high permeate flux at low operating pressures, combined with good choloramine resistance.
The NTR-759 HR exhibits up to 99.5% NaCl rejection. 99.9% Na2SO4 rejection and 96% isopropanol rejection, when tested at 1.5 MPa and 25°C on 1500 ppm solution. Ion rejection of this membrane at the low salt concentration depends drastically on pH. Accordingly this phenomenon suggests electrical charge affected by a small number of carboxylic acid in the membrane is important.
Spiral wound modules incorporating this membrane has been used to produce ultrapure water.View full abstractDownload PDF (1223K) -
Yoshiyuki Miyaki1991 Volume 16 Issue 4 Pages 233-238
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSCharge-mosaic membranes were fabricated from pentablock copolymers of the BABCB type, poly (isoprene-b-styrene-b-butadiene-b- (4-vinylbenzyl) dimethylamine-b-isoprene), by selectively introducing anion-and cation-exchange groups into the micro-separated phases. The three-layer lamellar structure of the starting pentablock copolymer films was not disturbed by the modification. The resulting membranes showed negative osmosis for aqueous solutions of salts and highly selective transport for sodium chloride in mixed solutions of low-molecular weight organic non-electrolytes and sodium chloride when the membranes were applied to dialysis process. The selectivity was much higher than those for conventional porous membranes, reverse osmosis membrane and dialysis membrane. On the other hands, the membrane exhibited an apparent piezodialytic effect in the region of low salt concentration (<0.01M) when they were applied to piezodialytic process. The salt enrichment increased with increasing applied hydrostatic pressure difference or decreasing salt concentration. These data and recent new challenges in the membrane fabrication make us expect the advent of some practical uses of charge-mosaic membranes in the future.View full abstractDownload PDF (790K) -
[in Japanese]1991 Volume 16 Issue 4 Pages 239-251
Published: July 01, 1991
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDownload PDF (1402K)
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