Adsorption of hydrogen and methane molecules to MgO surfaces was investigated by means of HartreeFock and density functional methods. The slab model as well as the cluster model were employed in the latter. The dissociated products were stable for a pair of three coordination (3c-3c) sites which were realized at the corner of the cubic crystallite, whereas unstable for the edge (4c-4c) sites and the sites on flat surface (5c-5c). Mixed (3c-4c) or (4c-3c) sites showed much weaker stabilization. As the coordination number decreases, the following changes are observed; (1) the HOMO levels shift to higher energy, (2) the LUMO levels shift to lower energy, (3) the band gap becomes narrower, and (4) the atomic charges of the surface Mg and 0 atoms decrease. This strong site dependence was explained in terms of the enhanced local covalency.
Adsorption of met hane showed a similar reaction profile as hydrogen although the product was stable only in the Mg-CH₃ and O-H bond formation. A common feature to the H-H and C-H bond fission over the ionic materials such as MgO is (1) the polarization of adsorbate bond at the initial stage of reaction and (2) then heterolytic (ionic) fission. An important factor of the catalyst side is to stabilize the elongated H-H and C-H bonds by the partial formation of new bonds. The Mg-O distance 0.2106 nm seems to be geometrically advantageous for these reactions.

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Enthalpies of fusion of binary organic mixed crystal systems, which consist of the naphthalene-2-naphthol, azobenzene-stilbene, azobenzene-diphenylacetylene, and azobenzene-bibenzyl systems, were determined by means of the differential scanning calorimetry (DSC). The relationship between the results obtained and the phase diagrams of these systems was discussed.
In the naphthalene-2-naphthol and azobenzene-stilbene systems, phase diagrams exibit Roozeboom's type I, i.e., the melting points of all mixtures lie between those of the pure components. In these systems, minimum values of enthalpy of fusion were found in about 0.6 and 0.7 mole fractions of 2-naphthol and stilbene, respectively.
On the other hand, in the azobenzene-diphenylacetylene and azobenzene-bibenzyl systems, the phase diagrams exibit Roozeboom's type III, i.e., two components in each system form a continuous series of mixed crystals with a minimum melting point. In the former system the minimums of the melting point and enthalpy of fusion agreed with each other in the composition of about 0.4 mole fraction of azobenzene. In the latter system, however, the dependence of enthalpy of fusion on the composition was similar to that of the azobenzene-stilbene system except that another minimum of the enthalpy of fusion appeared in about 0.2 mole fraction of azobenzene.
Partial molar enthalpies were shown for the naphthalene-2-naphthol and azobenzene-diphenylacetylene systems.

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Water in Oil type emulsion is in thermodynamic unstable state. The enlargement of the water drops and phase change or phase separation could be occurred by the duration of reservation. The aim of this study is the in situ monitoring of this phase change of emulsion by using Quartz Crystal Microbalance (QCM) method. Sodium hydroxide aqueous solution was used as the water composite, and the used oil phase was liquid paraffin. Emulsifier for W/O emulsion was sorbitan sesquioleate (monoester: diester =1: 1). W/O emulsion (water ratio: 60%) was prepared by stirring at 1000 rpm. This type of emulsion is relatively unstable because of the hydrolysis of ester emulsifier by NaOH. The silver coated crystal was immersed in the emulsion and the resonance frequency was monitored by frequency counter. After 10⁴ secs of immersion, the emulsion was suddenly destroyed. At this time, the resonance frequency showed large decrease (∼MHz). As a reference, experiment similar to this was tried with various amounts of additional emulsifier. With small amounts of additional emulsifier, the timing of decrease of resonance frequency was recorded in the early stage. So this method could be a new monitoring method for the state of W/O type emulsion.

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O-Allylation of alcohols with allyl alcohol catalyzed byPd(OAc)₂-diphosphinoalkane was investigated. Pd(OAc)₂-dppb[dppb =1, 4-bis (diphenylphosphino) butane] was found to be the most efficient catalyst, and the reaction proceeded effectively in aromatic hydrocarbon solvents such as xylene or toluene under neutral conditions. In the reaction of ethanol and allyl alcohol, the yield of allyl ethyl ether increased from 52% to 89% with increasing the [Ethanol] / [Allyl alcohol] ratio. The selecetivity of allyl ethyl ether was low at the early stage of the reaction, but increased with the progress of the reaction. Allyl ethers of various alcohols were also synthesized in high yields by this Pd(OAc)₂-dppb catalyzed O-allylation with allyl alcohol.

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NO_x removal catalysts from the combustion exhaust gas are recently the subject of intense study. The Cu/MFI catalyst is supposed to be the most probable catalyst because its activity is high even in the O₂ rich conditions. The durability against heat and catalyst poisons in the exhaust gas is important to adopt the catalysts in the actual combustion exhaust gas. Especially, the exhaust gas from Diesel engines generally contains ca.50 ppm of SO₂. To know the level and the mechanism of SO₂ deactivation is important. In this study, we discussed the deactivation mechanism on the Cu/MFI catalyst. In the catalysts evaluations after 300 °C treatments, the catalyst deactivated only after the SO₂ treatment. The XPS analysis revealed that the Cu species in the catalyst changed into sulfate form. We also tried to c larify the local structure of copper by XAFS (XCANES and EXAFS) technique. Cu species in the fresh catalyst were nearly regular tetrahedral coordination. The bond length was estimated at 1.94 Å. After the SO₂ treatment, the local structure of Cu changed to distorted octahedral symmetry. The Cu-0 (zeolite framework) bondings loosened from 1.94 Å to 1.99 Å. New bondings at 2.34 Å formed. The formation of Cu-O (SO₄^2-) bonding would result in the creation of longer bondings. In the catalysts evaluation after 500 °C and 700 °C treatment, the catalytic performance of the samples was almost the same in each temperature. The migration of Cu species from the active sites and the dealumination of zeolite framework would be dominant at these temperatures.

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Porous montmorillonite-polyamide complexes (PMPC) were prepared as follows; first, porous montmorillonite-6-aminohexanoic acid (AHA) monomer complexes were obtained by freezing the montmorillonite/AHA/water sol in liquid N₂ followed by evaporating of the ice under vacuum, and then the monomer complexes were polymerized at 250∼265 °C in vacuum-sealed tube.
PMPC was constituted of the pores having a diameter of several, μm and the walls having a thickness under 100 nm. In the interlayer space, 1∼3 layers of polyamide were complexed as the randomly mixed layer phases of mono and two, or two and three molecular layer arrangement.
PMPC was water-resistant when the amount of polyamide comp lexed is over 0.9∼1.2 polymer units/Si₄O₁₀ and showed the restricted swelling and the ion-exchange properties in spite of complex with polymer.
Furthermore, in the case of Cu²⁺-exchanged PMPC, _L-lysine was intercalated into the interlayer space of PMPC, and quickly formed the Cu²⁺_-L-lysine co-ordinated compound, maybe [Cu (_L-Lys)₂]²⁺ type, in-situ. The arrangement of the co-ordinated compound depends on the amount of polyamide complexed.

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The thin membranes of perfluorocarbonsulfonic acid which had 10 μm and 11 μm thickness were made by dipping the poly (tetrafluoroethylene) (PTFE) and hydrophilic PTFE in the solution of perfluorocarbonsulfonic acid, drying and hot-pressing at 140 °C. The thin membranes obtained and Nafion ®117 were tested in the single cell of fuel cell, using O₂/H₂ gases, at 55 °C, 1 atm. It was sho wn that the area resistance of the thin membrane and Naflon®117 were 0.02 Ω cm² and 0.26 Ω cm², and, the specific resistivity estimated by using the dry membrane thickness were 0.18 Ω cm and 0.15 Ω cm, respectively. The single cell performance when the thin membrane was used was better than when Nafion®117 was used, which was the effect of decreasing of the membrane thickness.

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A separation technique which is called “Solvent Sublation” was studied for removing uranyl ions from aqueous solutions at 298 K with di (2-ethylhexyl)phosphate (D2EHPA) in heptane or D2EHPA containing trioctylphosphine oxide (TOPO) in kerosene. The effects of operating factors on the percent removal of U(VI) were examined in counter-current flotation operation. Furthermore, the adsorption capacity of U(VI) per unit specific surface area was examined in terms of the gas holdup and bubble diameter. (1) The percent removal of U(VI) lowered with increasing electrolyte concentration, but increased with addition of sodium dodecyl benzenesulfonate (DBS) as a collector. However, the effect of DBS concentration on the percent removal of U(VI) lowered as the gas flow rate (u_G) increases. The removals from aqueous solution of UO₂²⁺ dissolved in sea water were found to be about 80% without addition of DBS at u_G= 0.265 cm s^-1 and u_G=0.106 cm s^-1. (2) The gas holdup (ε_G) increased with increasing gas flow rate, liquid flow rate (u_W) and ionic strength; little effect of DBS concentration on ε_G was found. (3) The gas bubble diameter increased with increasing gas flow rate, but decreased as the ionic strength increases. The effects of liquid flow rate and DBS concentration on the percent removal of U(VI) were of little significance. (4) The adsorption capacity of U(VI) per unit specific surface area of gas bubble dispersion increased with an increase in the flow rate ratio of liquid to gas (u_W/ u_G), and attained to a plateau as an equilibrium value, which decreased as an ionic strength increases.

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A diffusive simple sampler for ozone, utilizing strongly fluorescent dimers formed by oxidative dimerization of P-acetamidophenol and ozone, has been developed and fundamental performances were reported previously. This paper describes the effects of temperature, pore size of membrane filter, wind velocity, various amounts of NO₂, SO₂, NO₂^-, SO₃^- on sampling rates and variations of sampling rate by using diverse membrane filters.
The results obtained ar e as follows, (1) The effect of temperature on sampling rate was negligible. However, the sampling rate increased when the internal pressure of the sampler has become higher than the external pressure and a membrane filter was swollen. (2) The variation on sampling rate were less than 4.2% for the same lot No. of membrane filter, and were 8.7% for the different lot No. of membrane filter. (3) The sampling rate increased about 5% per unit wind velocity (m/s), when the sampler placed parallel to the direction of the airflow. (4) The interference of NO2 was positive, and the sampling rate of NO₂ was 11.6% of that of ozone. (5) The interference of NO was slightly negative. (6) The sampling rate was decreased approximately 25% by the interference of coexisting SO₂.

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Atmospheric deposits (wet and dry deposits) were collected in Nagaoka which is located in the center of Niigata Prefecture, Japan, and concentrations of chalcogen elements (sulfur, selenium and tellurium)and other chemical constituents were measured to investigate the sources of sulfate. Remarkable seasonal variations were observed in concentrations which were lower in summer and higher from winter to spring while in depositions with less in summer and a lot from autumn to winter when precipitation increases. The ratios of Se/nss-S and Te/nss-S also showed seasonal variations with higher amounts in winter and lower in summer, further, high correlations among these three elements were recognized. As was reported, there is the possibility of the use of tellurium as a tracer of coal and selenium as a coal and oil combustion effluent. It is considered that sulfate in atmospheric deposits in Nagaoka is influenced by fossil fuel combustion effluents including coal in East Asia.

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Acrylic acid and sodium 4-vinylbenzenesulfonate (sodium styrenesulfonate) were grafted on a polyethylene film by the radiation-induced graft polymerization. The electrolyte membrane which had 2.45meq/g of sulfonic acid and 5.98 meq/g of carboxylic acid as the ion exchange capacity was produced. X-Ray diffraction and Fourier transform infrared spectrum of the synthesized membrane were measured. The thermal decomposition of this membrane occurred at 250 °C. Fuel cell performance tested with these membranes, showed a higher initial performance with the membrane containing sulfo and carboxy groups than that with Aciplex®-S, which is the perfluorocarbon-sulfonic acid membrane. The membrane containing carboxy group only did not work as the electrolyte.

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Effectiveness of incorporating insoluble hexacyanoferrate (II) into the pores of macroporous ion exchange resins by utilizing their ionogenic groups has been examined. Sorption-desorption-regeneration performance for cesium separation is compared for the composites prepared by using various ion exchange resins and insoluble hexacyanoferrate salt-forming reagents.
Among insoluble hexacyanoferrate (II) salts impregnated, copp er (II)exacyanoferrate (CuFC)is the best reductant for a redox type iori exchanger having ion exchanging and electron exchanging functions. Therefore, this CuFC-ion exchange resin system shows excellent sorption-desorptionregeneration performance for cesium separation. Anion exchange resins work better than cation exchange resins as supports to incorporate CuFC. Excellent composites for cesium separation are obtained from anion exchange resins containing weakly basic groups rather than strongly basic ones. For example, Amberlite IRA-94S (weakly basic styrene-divinylbenzene-based resin) /CuFC composite can be repeatedly used more than seven times for cesium separation from 3 mol dm^-3 sodium nitrate solution.

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CuS-coated ZnS particles were prepared from the suspension of ZnS particles in copper (II) nitrate solution by ion-exchange reaction: ZnS (s) + Cu²⁺ → CuS(s) + Zn²⁺. The morphology of CuS-coated ZnS particle depends on kind of solvents, reaction temperatures and copper (II) nitrate concentrations. Most uniform coating was achieved by the reaction in methanol at 50 °C under [Cu ( NO₃)₂ ] = 0.01 mol d m^-3. Reactions in water and ethanol at 0∼50 °C or in methanol at 0 °C and 30 °C gave island-type deposits and/or particles formed in liquid phase.

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It was clarified that 3-cyano-2-methyl-1-phenylisothiourea (1) reacted with silver nitrate in the presence of triethylamine to give rise to N-cyano-N'-phenylcarbodiimide (2), which reacted with 1 to give 2-cyanoimino-4-[(N²-cyano-An-phenylamidino)imino]-6-methylthio-1, 3-dipheny1-1, 2, 3, 4tetrahydro-1, 3, 5-triazine (3). In a similar manner, compound 1 reacted with two molar amounts of phenyl isocyanate, phenyl isothiocyanate and diphenylcarbodiimide in the presence of triethylamine to afford corresponding tetrahydro-1, 3, 5-triazines 11, 12 and 13 respectively.

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Hydroxycancrinite containing iron (III) ions in the framework has been prepared at 80 °C for the first time.
NaA1O₂ (system 1) or AI(OH)₃ powder (system 2) was added into a mixed solution of Na₄SiO₄ and Fe (NO₃)₃ slowly with stirring. Then NaNO₃ was added. The reaction mixtures were kept at 80 ± 1 °C for 1∼6 weeks.
The so lid products obtained were characterized by XRD, IR, ICP-AES, SEM and measurement of magnetic susceptibility. These analyses showed that iron (III) ions were present in the lattice framework and the extent of substitution of iron (III) went up to ca.10% (system 1) and 15% (system 2).

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