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Volume 46, Issue 1
Displaying 1-5 of 5 articles from this issue
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Shigeki TOYAMA, Tsutomu ARAGAKI, Kazunori MURASE, Hassan Mohamed SALAH1992 Volume 46 Issue 1 Pages 3-21
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSMomentum and heat transfer in falling film evaporation were studied to provide basic data for this type of evaporator with high performance. Then, a roof-type desalting solar still was studied as the application.
1) Momentum and heat transfer in falling film evaporation
Liquid hold-up flowing down a tube was measured and decrease of the hold-up to enhance heat transfer was observed at a low velocity range by the effect of wound string. The enhancing effect of range by the effect of various projections at the surface was measured by an electro-chemical method. The measurement could clearly indicate the transition zone from laminar to turbulent flow.
The shape meniscus and velocity of liquid flowing down a groove were numerically calculated and were coincided with the experiment. Convection with respect to the liquid cross section was also numerically calculated and the enhancing effect on heat transfer and evaporation was discussed.
2) Roof-type solar desalting still
Computer programs were developed to simulate static and dynamic characteristics of the still and were proved to be sufficient by test plants. The program could calculate design and operational parameters.
Materials for the roof were also discussed and an idea to displace it to a panel of photovoltaic cell was investigated. Inland Marine Oasis Solartopia was conceptually designed to evaluate the idea.View full abstractDownload PDF (16308K) -
Katsuya UESUGI, Shogo SUEHIRO, Hiroshi NISHIOKA, Tetsu KUMAGAI, Tohru ...1992 Volume 46 Issue 1 Pages 22-26
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSTrace amounts of nickel in sea water and common salt were determined by atomic absorption spectrophotometry in conjunction with solvent extraction technique. Nickel reacted with 5-nitro-salicylaldehyde-4-phenyl-3-thiosemicarbazone (NSPS) to form a complex, which was extracted into methyl isobutyl ketone. The separated organic phase was sprayed into an acetylene-air flame. The optimum conditions on the extraction of nickel were examined. The effect of coexisting diverse ions in the aqueous phase were also examined. Less than 15 μg of nickel was quantitatively extracted into 20ml of 2.5×10-3 M NSPS methyl isobutyl ketone solution from aqueous solution at pH 8.0-8.7, by shaking for 30 min. When a known amount of nickel was added to the artificial sea water and the sea water samples, the nickel was recovered satisfactorily. The coefficient of variation was 2.6% at 10 μg of nickel (n=6). Some samples of sea water, common salt and imported salt were analyzed.View full abstractDownload PDF (3219K) -
Generalized EquationsHaruhiko OHYA, Atsuo HAKAMAYA, Yasunobu HIRAOKA1992 Volume 46 Issue 1 Pages 27-36
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSA feasibility study is carried out theoretically for the separation of different ionic species of the same charge sign via repeated permeation through ion-exchange membranes in a multi-stage electrodialysis system. In order to avoid depletion and accumulation of ionic species in the retentate and the permeate streams, reflux lines on both sides of the system return the non-product streams from each stage to the previous stage.
Two types of cascades are considered. In the first type, called the ‘cross type’, there are two center cells, and the reflux streams from the second set of cells are mixed and fed jointly to the center cells. In the second type, the ‘straight type’, there is one center cell, and the depleted and concentrated reflux streams from the second stages are mixed and fed to the center stage.
A set of generalized equations for the concentration of each ionic species at each stage is derived for both cascade types. For ion-exchange membranes with perm-selective coefficients for ionic species 2 compared to ionic species 1, T21, of 2. 25, numerical calculations are carried out for systems with 6, 10, 14 and 18 total cell compartments. The separation is predicted for two ionic species of the same charge and identical concentration of 0.1 mol/l. For the constant current of 30 A/m2, the final mole fractions of species 1 in the depleted stream for 18, 14, 10 and 6 cell compartments in the crosstype system are 0.93, 0.86, 0.76 and 0.63, respectively, and 0.73, 0.71, 0.68 and 0.63 for the straighttype system.View full abstractDownload PDF (6211K) -
Aijunm TONG, Yoshifumi AKAMA1992 Volume 46 Issue 1 Pages 37-41
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe separation and simultaneous determination of Al (III), Ga (III) and In (III) in the form of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMEP) chelates by reversed phase high performance liquid chromatography are described. These chelates are separated on a 30% octadecyl modified ODS column by using acetonitrile saturated with sodium chloride as the mobile phase. When a mobile phase of acetonitrilewater mixture was used, the indium chelate did not appear on the chromatogram, owing to on-column dissociation. The stabilities of these chelates during the chromatographic process are Al>Ga>In. The results of determinations of these metals in synthesized samples are agree well with the certified values.View full abstractDownload PDF (3589K) -
Yoshifumi AKAMA, Mari WAKIMOTO1992 Volume 46 Issue 1 Pages 42-45
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSA method for the simultaneous determination of Mg and Ca ions in solar salt was studied by ion chromatography with a conductivity detector. The samples, about 25g, were dissolved in about 150ml of water and the solution was filtered through a filter paper into a 250ml volumetric flask. Then 1ml aliquot of this solution was pipetted into a volumetric flask and diluted to 100ml with water. A 100μl aliquot of the sample solution was analyzed by an ion chromatograph equipped with a precolumn (PCX 1,50mm×4.6mm i.d.) and a separation column (SCX 1,250mm×4.6mm i.d.) using 2 mM ethylenediamine-4 mM tartaric acid as a mobile phase (2ml/min).
Linear calibration curves were obtained up to 2.0 ppm for Mg and Ca. The detection limits (S/N=3) were 5 ppb for Mg and 7 ppb for Ca. Relative standard deviations (n=5) were less than 3.1% for 0.016-0.09% of Mg and 2.8% for 0.0420.20% of Ca in solar salt for the simultaneous determination of these elements.View full abstractDownload PDF (2273K)
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