Sadaaki Murakami

A shallow-sea ecological model using an object-oriented programming language

Abstract The purpose of this study is to construct a model that can predict the impact on fisheries caused by coastal development activities. To accomplish this, many species of fish must be incorporated in the model, because each type of fish has a different value as a fishery resource and a different behavior for the same impact. In addition the effect of fish swimming must be considered because even when the total resource amount of fish does not change, fish may still disappear from the object area. These factors make the model structure complicated. Meanwhile, a new concept called ‘object oriented programming’ (OOP) is attracting the attention of modellers. In this paper, we have constructed a model called the ‘hallow-sea ecological model’ (SSEM), by using Smalltalk, which is representative of the OOP language. This showed that the fishing ground environment are expressed very flexibly and plainly by Smalltalk. Furthermore, we incorporated the effect of fish swimming by preference using a multicriteria analysis. The result of numerical experiments suggested that the effect of fish swimming by preference may be the essential factor for shallow-sea ecological modelling.

Acid equilibria of methylthymol blue and formation constants of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with methylthymol blue.

Potentiometric and spectrophotometric studies on acid equilibria and reactions with Co(II), Ni(II), Cu(II) and Zn(II) for Methylthymol Blue (MTB) are described. The equilibrium constants have been calculated. MTB has been found to form 1:1 and 2:1 (mole ratio of metal to ligand) complexes, including protonated ones. The probable configuration of the complexes and the effects on the stabilities have been discussed.

Mercury pollution in Tokuyama Bay

The sediments and aquatic life of Tokuyama Bay, Japan, have been polluted by mercury effluent from chloro-alkali plants. In total, about 3&0 tons mercury were released from these plants and 6.64 tons of mercury were discharged into the bay in waste waters between 1952 and 1975, when mercury cells were employed. A number of surveys to study mercury pollution and the effectiveness of control measures in this area were conducted in the early 1970’s by our laboroatory and other agencies. Analysis of human hair from Tokuyama Bay residents contained less mercury than those in Minamata and Agano districts, Japan, where serious mercury poisoning had occurred, but were contaminated with more mercury than those in other unpolluted areas. No occurrence of Minamata disease has been reported in the Tokuyama district.

Formation constants of zinc(II) complexes with Semi-Xylenol Orange.

A potentiometric and spectrophotometric investigation on the formation of zinc(II) complexes with Semi-Xylenol Orange (SXO or H(4)L) is reported. In an aqueous solution (mu = 0.1), three 1:1 complex species, MH(2)L, MHL(-), ML(2-), and a 1:2 complex, ML(6-)(2), seem to exist. In a strongly alkaline medium (above pH 12.5) the complexes may dissociate to give zinc hydroxide and L(4-). The formation of a hydroxy complex is not observed. The absorption maxima are at 445 nm (MH(2)L), 466 nm (MHL(-)) and 561 nm (ML(2-)), the molar absorptivities being 2.34 x 10(4), 2.42 x 10(4) and 3.14 x 10(4) 1.mole(-1) .cm(-1) respectively. The formation constants are (at 25 +/- 0.1 degrees ) log K(M)(ML) = 11.84, log K(M)(MHL) = 7.13, log K(M)(MH(2)L) = 2.70, log K(M)(ML(2)) = 16.60.

Equilibria and kinetics of aluminium(III) complex formations with semi-xylenol orange and semi-methylthymol blue

Abstract The equilibria and kinetics of complex formations by Al(III) with Semi-Xylenol Orange (SXO) and Semi-Methylthymol Blue (SMTB) in aqueous solution have been investigated potentiometrically and spectrophotometrically. Al(III) forms three complex species, AlHL, AIL − and Al(OH)L 2− . The stability constants were determined and their structures have been discussed. Kinetic results are interpreted in term of a two-step mechanism including a pre-equilibrium. Second order rate constants of the forward reaction between the Al(III) aquo ion and ligand acid species were determined from the dependence of the reaction rate on the hydrogen ion concentration. Substitution of the water in the Al(III) aquo ion by the ligand species is assumed to involve several water molecules including the outer sphere water and the removal of these is assumed to be the rate determining. The rate was accelerated by the addition of a polar organic solvent.

Equilibria of iron(III) complexes with xylenol orange and methylthymol blue

Abstract A potentiometric and spectrophotometric study of Fe(III) complexes with Xylenol Orange (XO) and Methylthymol Blue (MTB) has been made. The formation constants for the Fe(III) complexes with XO and MTB were determined. Evidence was found for the formations of 1:1 and 2:1 complexes (metal:ligand) and it was assumed that protonated and hydroxo-complexes exist in addition to the simple complex in each case. The hydroxo-complexes are stable over the pH range of 7–12. Suggestions are made concerning the probable structures of these complexes.

Electroanalytical and spectroscopic studies on metal complexes with sulphonphthalein derivatives—I: Determination of stability constant and composition of Cu(II)—Xylenol orange complex

Abstract The Cu(II) complex with xylenol orange has been studied by electroanalytical and spectroscopic methods. The stability constant of the complex was calculated from polarographic data, and the composition was determined from the i d -mole ratio (Cu(II) to xylenol orange) and the absorbance mole ratio plots. The reduction mechanism is discussed.

Electrostatic and non-electrostatic thermodynamic quantities of reaction of bivalent metal ions with ethylenediaminetetraacetate

Abstract The thermodynamic functions for the formation of bivalent metal complexes with ethylenediaminetetra-acetate in aqueous solution have been analyzed in terms of electrostatic (el) and nonelectrostatic (non) parts. The rather smaller exothermic reactions than expected from the high stability of the complexes have been found to arise because the exothermic ΔHnon value is compensated by the endothermic ΔHel value. The ΔHnon increases linearly with a measure of softness of metal ion introduced by Glopman. The correlation has been pointed out between the ΔHel and the heat of hydration of the corresponding metal ion. The average interionic distance of metal and charged donors in the complex molecule calculated from the ΔGel value was compared with the effective ionic radius of metal ion on hydration and with the crystal ionic radius. This comparison suggested similarity in the complex structures throughout the metal series studied.

Correlation between the hard and soft character and the visible absorption spectra of Xylenol Orange and Methylthymol Blue complexes with bivalent metal ions

The changes in the spectra of Xylenol Orange and Methylthymol Blue complexes with several bivalent metal ions have been investigated in terms of the chemical bonding between the phenolic oxygen atom and the metal ion, and the hard and soft character of the donor and acceptor. The value of this approach to indicator action is discussed.

Eutrophication control in the Seto Inland Sea

The Seto Inland Sea, surrounded by the four large islands of Honshu, Shikoku and Kyushu, is famous for its scenic beauty and coastal fishery. However, the beauty of this area has been threatened by a high concentration of human population and industry which contribute to water pollution and eutrophication problems. In this study, we examine the present water pollution problems of this area; we have studied the history of water pollution in the Seto Inland Sea, the influx of nutrients into all sections of this area and the relationship between eutrophic levels and fishery productions in each section of the Seto Inland Sea. We have also analyzed the secondary organic pollution which is a result of the primary photosynthesis production and the comprehensive eutrophic situation of the sea and each of its sections, in comparison with other coastal seas in Japan. From the results of this evaluation, we propose the following four strategies for eutrophication control in the Seto Inland Sea: (1) Elimination of nitrogen (N) and phosphorus (P) discharging loads by means of controlled chemical fertilizer consumption and recycling of human and livestock excreta as fertilizer (as a conclusion of the budget of N and P in Japan); (2) Consolidation of treatment facilities for the point sources of pollutants such as domestic sewage and industrial waste water; (3) Diversion of the discharging N and P loads from the Seto Inland Sea into the adjacent open sea areas of Japan which have a larger carrying capacity through the exclusion system such as a sewer system (through comparison with each adjacent sea area of Japan); (4) Dredging of sediments over the polluted zones.