The reaction between quinones and sodium sulfite has been investigated and is discussed in terms of the redox potentials of quinones (EQ) in reference to that of sodium sulfite (E_q). The rate of the addition reaction in various quinone-Na₂SO₃ conbinations was found to depend on the ΔE value (ΔE=E_Q-E_ss). In the reaction system in which 4E values were smaller than 50 mV, the intermediates which gave hydroquinonesulfonates were detected by the. polarographic method. The results show that prototropy is the rate-determining step in the addition reaction and the rate of the prototropy depends on the 4E value. t Mechanism of Reactions between Quinones and Sodium Sulfite. Relationship with Oxidation-Reduction Potential. VII.

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The catalytic activities of nine spinel oxides containing cobalt were examined for oxidation of ethyl methyl ketone (EMK) to biacetyl. The formation of biacetyl was observed, more or less, over all the oxides in a lower temperature range (473 K to 523 K). The selectivity of biacetyl decreased with the increase in temperature, biacetyl formation being replaced by complete oxidation. Based on the product distribution at 473 K, the oxides were classified into two groups: one were selective for biacetyl and the other favored oxidative scission of EMK. In the first group, Co₂NiO₄ had the highest selectivity for biacetyl, while CuCo₂O₄ showed the highest specific rate for EMK conversion. In the latter group, Co₂MnO₄ gave equimolar amounts of acetic acid and acetaldehyde, but acetaldehyde was obtained predominantly on MgCO₂O₄ and CoAl₂O₄. It was found that the catalytic activities of the cobalt-spinels for biacetyl formation or partial EMK oxidation were dependent on the type of spinel, i. e., (A)M²⁺Co₂³⁺ O₄; (B) Co²⁺M₂³⁺O₄;(C) Co₂²⁺M⁴⁺O₄ Among the spinels of the same type, the activities were well correlated with the electronegativities of metal ion or the heat of formation of component oxides MOn. The deviation of the activities of Co₂NiO₄ and Fe₂CoO₄ from the correlations suggests that the cobalt ions at the A sites (tetrahedral) are more active than those at the B sites (octahedral). Apart from these correlations, temperature programmed desorption measurements revealed that the catalytic activities of the oxides ran parallel with the amount of adsorbed oxygen on the oxides. This fact suggests participation of the adsorbed oxygen in this type of oxidative reaction.

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Image formation by use of poly(vinyl alcohol) (PVA) film containing copper( II) chloride and its mechanism have been investigated. Brownblack image was obtained by exposing the PVA film to ultraviolet light and then heating it. Also relief image was formed by washingout with water, since PVA of the image area became insoluble in water. The PVA film had both the properties of photosensitivity and thermosensitivity. Copper(II) chloride in PVA was reduced to form copper(I) chloride by exposing to ultraviolet light, with the simultaneous oxidation of PVA. The same redox-reaction took place on heating the PVA film at 130°C for about 7 min. The rate of the thermal reaction increased in the presence of copper(I) chloride or copper. The results suggest that the image formation takes place via the following stages:
_??___??__??_
2CuCl →hν Cu + CuCl₂
CuCl or Cu formed in this reaction acts as a catalyst for the subsequent thermal reaction. Therefore, the thermal reaction takes place preferentially in the area exposed to ultraviolet light to form Cu and oxidized PVA, that is, to form brownblack and insoluble image. Other products, such as CuO and Cu₂O may be formed as colored products for the image formation.

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The photoactivation type physical developer, previously proposed, could stand for a longterm storage. For example, a developer consisting of a methanol-water solution of silver salt (0.5 mol/l) and p-benzoquinone (0.47 mol/l) showed little or no deterioration after storage for two days in the dark. The resolution of developed image depended on the anion species in the solution and also on the species of the nucleus metal. The typical value of the resolution was 200 line pairs/mm. Though the developing time as short as 4---5 minutes could yield an image of transmission density 3, the developing rate had to be improved further for meeting practical requirements. In this paper, an investigation was made to find out better precursors for the developing agent (reductant).
Precursors were chosen from families of quinones and diazonium salts. Among many compounds, p-diethylaminobenzenediazonium tetrafluoroborate was found to give the best result. When this compound was chosen as the precursor and dissolved into a methanol-water solution (0.13 mol/l) together with a silver salt (0.5 mol/l), the developing rate was 3 times higher than that of the former p-benzoquinone type developer. This rate is satisfactorily rapid for practical use. The stability during the storage in the dark and resolution were not lost by the replacement of p-benzoquinone with the diazonium salt. For the palladium nucleus, the exposure energy required for getting the transmission density of unity was O.8mJ/cm², which was lower by factor of 4 than that for silver nucleus.

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The high proton conduction of antimonic acid was found to be maintained even after thermal treatments at 513, 593, 773 and 893 K. The conductivities of the thermally treated samples were comparable to that of untreated antimonic acid, i. e., about 10^-1S·m^-1, at room temperature when the relative humidity was high (Fig.1). The number of protonic transference was confirmed to be unity for each sample (Fig.2). Instrumental analyses by using TG, X-rays and IR showed that antimonic acid loses water and a part of oxygen in the temperature range 513-893 K. (Figs.3 and 4), where the crystal structure changes continuously into that of Sb₈O₃ (Figs.6 and 7). The ion exchange capacity of each sample was found to coincide with the amount of its constitution water (Figs.8 and Table 1). It is emphasized that the skeleton structure of antimonic acid was maintained even after the treatment at 893K. The high conductivities, observed at high relative humidities regardless of the treatment temperature, suggest the importance of physisorbed water. The isotherms of water adsorption (Fig.9) indicated that the conductivity increased drastically with an increase in water adsorption only when the surface coverage (θ) of water exceeded unity (Fig.10). The proton conduction in Grotthus mechanism is considered to be feasible at θ>1 (Fig.11).

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The crystal structure of calcium hydrogenphosphate dihydrate (CaHPO₄·2H₂O) was analogous to that of gypsum (CaSO₄·2H₂O). Its dehydration process was not so simple as that of CaSO₄·2H₂O, because 0.5 mol of condensation water was present besides 2.0 mol of crystallization water.
TG-DTA curves of the dihydrate (heating rate, 5-10°C/min) showed three endotherms and weight losses of three steps, which occurred at the temperatures of 140, 160 and 185°C. This finding indicated that the 2.0 mol of crystallization waters had unequal bond strengths to CO+ ions. X-ray diffraction data of samples obtained by the above heating showed only two phases: the dihydrate and the anhydrate, but the formations of di- and tri- phosphate groups were detected in samples heated to about 180°C and 300°C, respectively, from paper chromatographic analysis. Therefore, it was found that the dehydration of the dihydrate, the condensations of the anhydrate and diphosphate proceeded simultaneously parallel to one another. Those di- and tri- phosphate groups were fairly stable so that γ-Ca₂P₂O₇ crystallized completely before about 600°C.
Although the weight loss of the sample heated at 100°C reached an equilibrium state corresponding to elimination of about 0.5 mol of crystallization water and the formation of some intermediate phase was suggested, the existence of a new phase was not confirmed from X-ray diffraction patterns.

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The formation fraction of ZnAl2O₄ was measured by the chemical analysis, and microstructural observations were carried out by means of SEM and EDX for the specimens heated at 700, 800 and 900°C for various duration. The increase in the fraction of ZnAl₂O₄ was apparently interrupted in the presence of LiF after abrupt increase in the initial stage of reaction at each temperature (Fig.1).
Fig.2 shows that ZnAl₂O₄ was formed via four steps in the microstructures as follows; Step I: Initiation of the action of LiF on the surface of Al₂O₃ particle. Step II: Formation of ZnAl₂O₄ layer around Al₂O₃ particle and intermediate phase containing LiF, Zn and Al (Figs.4 and 5) between ZnAl₂O₄ and Al₂O₃ phases. Step III: Formation of C-lithium aluminate layer between ZnAl₂O₄ and intermediate phases. Step N: Existence of intermediate phase at the center of Al₂O₃ particle.
Figs.3 and 7 show the observed range of each step as a function of heating temperature and time, and their ranges in the rate curves of ZnAl2O₄ formation with various concentration of LiF, respectively. ZnAl2O₄ formation was accelerated by the rapid migration from Al₂O₃ to ZnO phases through the intermediate phase in the initial stage of the reactions (Step I and II) and interrupted apparently by the slow diffusion of AP⁺ and Zn²⁺ ions through the ZnAl₂O₄ layer and C-lithium aluminate phase formed inside of ZnAl₂O₄ layer in the latter stage of the reactions (Step III and IV). The elevation of heating temperature and the increase in the amount of LiF increase the quantity of intermediate phase and promote the ZnAl₂O₄formation in the initial stage of the reactions (Figs.6 and 7).

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On the basis of the measured values of reaction temperature and induction period for dehydration of calcium sulfate dihydrate in 20-55% sulfuric acid solutions obtained by means of a wet DTA in previous investigation', the method to set up an empirical equation that expresses the relation among the three factors of sulfuric acid concentration Z (%), reaction temperature y (°C) and induction period x (min) was studied. In analyzing data the following equations of approximational function were used;

y=Yx^-m
Y=-a_1e^b1z+C₁
m=a₂Z^bz+c₂
These equations were linearized, and tested by regression analysis.
The relation among the three factors of Z, y and x was represented as follows:
y=(-4. 886e^0.04897Z+111.33)x^{-(1. 362x10-10Z5. 093+0. 01410)}
It was confirmed comparing with the measured values that above empirical equation is applicable to the region of Z-=-20-55% and x=1-30 minute. From the above results, it became possible to show the phase diagram for metastability of calcium sulfate dihydrate in sulfuric acid solution by isochrones of induction period, and the phase diagram thus expressed was considered to be useful in practical use.

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The formation constants (K) of 1 to 1 metal chelates of 2-[1-(2-methoxy-5-sulfophenyl)-3-phenyl-5-formazano]benzoic acid (CMF) with cobalt(II), nickel(II), copper(II) and palladium(II) have been determined spectrophotometrically in aqueous solution at 1, 0.1(NaClO₄)and 26±1°C. The formation constants obtained decrease in the order Cu>Pd>Ni>Co, the log K values being 18.1, 14.90, 11.50 and 11.25, respectively. The copper chelate has an absorption maximum at 580 nm and the maximum absorbance is obtained in the pH range 3.5 to 9.5. The calibration curve obeys Beer's law over the range 0 to 65 μg·25 cm^-3 of copper; the molar absorption coefficient of the chelate and Sandell's sensitivity are 2.1 x 10⁴dm^-3·cm^-3and 3.O× 10^-3μg·cm^-2, respectively. The relative standard deviation of the absorbance was 3.37x 10^-3 for 1.2 μg·cm^-3 of copper. A large amount of Co(II), Ni(II), Pd(II) and Fe(III)interfered with the determination. The proposed procedure is as follows: To the sample solution containing up to 65 aug in a 25 cm3 volumetric flask, add 5 cm³ of acetate buffer (pH 3.5) and 2 cm3 of O.1% CMF. Dilute to the mark with water and measure the absorbance at 580 nm against the reagent blank as a reference.
The proposed method which is highly selective and rapid is applicable to the analysis of copper in zinc alloy die casting, food (chiken eggs, mother's milk) and biological materials (rat liver, kidney, blood, and bovine liver).

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Di-2-pyridyl ketone [2-furyl(thiocarbonyl)]hydrazone (DPFTH) was used as a reagent for the extractive spectrophotometric determination of copper(II). The proton dissociation constants of the ligand determined spectrophotometrically were pK_a1=2.88 and pK_a2=6.70 at 25°C and, μ=0.1. Copper (II) can be quantitatively extracted with DPFTH in benzene from aqueous solution buffered to pH 5-11. The extracted species has absorption maxima at 364 and 457 nm and obeyed Beer's law over the range 0-38 μg of copper(II) in 10 ml at 457 nm. The molar absorptivity at this wavelength is 1.42 × 10⁴l·mol^-1·cm^-1 and the coefficient of variation (n=12) of this method was 0.53% for 25.4μg of copper. Nickel (II), zinc(II), palladium (II), mercury (II), bismuth (III) and EDTA interfered with the determination. The composition of the extracted species was also discussed.

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Concentrations of 12 elements (Mg, Mn, Cu, As, Cd, Sb, Hg, Ni, Zn, Na, Cl, Br) in Diesel oil, regular gasoline and high octane gasoline were determined by instrumental neutron activation analysis (INAA).
The total of about 300 samples was directly activated in an irradiation pit of the Musashi Institute of Technology Research Reactor (MITRR). Liquid oil samples (30-50 ml) in polyethylene bottles were irradiated with a thermal neutron flux of 7.5 × 10¹¹n·cm^-2·s^-1 for 10min (short time method), 2 h (midle time method) and 10 h (long time method). The irradiated liquid samples were transferred to new polyethylene bottles and then bubbled with oxygen gas for 2---95 min in order to decrease activity from dissolved "Ar. The measurement was performed by use of a Ge (Li) detector coupled to an 8192 channel multichannel analyzer.
The concentrations of the analysed trace elements except Cl and Br showed logarithmic normal distribution for each of Diesel oil, regular gasoline and high octane gasoline. The geometric means for all the samples were evaluated on the basis of the cumulative frequency distribution curves. The evaluated geometric means were 0.033 ppb, 11 ppb and 0.60 ppb for Mn, Cu and As in Diesel oil, 0.031 ppb and 0.25 ppb for Mn and Hg in regular gasoline and 1.2 ppb for Hg in high octane gasoline, respectively. As a result, we found that the concentrations of trace elements in gasoline were lower than those in Diesel oil. This means that the gasoline is more refined. And the concentrations of Cl and Br in gasoline were higher than those in Diesel oil. From the correlation of concentrations of Na, Cl and Br in Diesel oil, it was found that the concentrations of Br were much lower than those of Na and Cl and that Na and Cl might dissolve as NaC1 compound. The ratio of Cl to Na concentration was increased in the order of Diesel oil, regular gasoline and high octane gasoline. So Br in gasoline was nearly the same concentration as Cl. The high concentrations of Cl and Br in gasoline might be mixed in refined process.

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Chemical ionization mass spectra with methane, isobutane or methane/solvent (9: 1) as a reagent gas are measured in order to elucidate their characteristics for 21 polycyclic aromatic hydrocarbons (PAHs) and 5 related compounds (Table 1). The results obtained can be summarized as follows.
1) In general, methane and isobutane CIs show appreciable difference in their spectral patterns, especially the relative intensities (%E) of M⁺., compared with El (Table 2, 3).
2) Methane CI-Charge exchange reactions with the reactant ions such as C₂H₄⁺, C₂H₅⁺and C₃H₅⁺ occur to form M⁺, since the ionization energies of PAHs are lower those of C₂H₄, C₂H₃ and C₃H₃ (Fig.1). Thus it seems to be possible to distinguish and identify isomers in PAHs by examining their M⁺intensities. There is a good correlation between the intensities of MH⁺ and the molecular weights of PAHs.
3) Isobutane CI-Some of the spectra show sufficient difference in the M⁺ and (M+i-C₄H₉)⁺ intensities to identify each PAH (Table 3).
4) Methane/solvent (methanol, acetonitrile, methylamine) CI - The spectral patterns show little difference, since dominant ionization processes are caused by proton transfer reactions with the protonated reactant ions resulted from solvents (Table 4). However, M⁺to MH⁺ intensity ratios are varied appreciably with kinds of solvents and are increased with increasing proton affinity of solvents (Fig.2).

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The stereochemical study of lupinines and their derivatives ([11], -[9]) was carried out by the analyses of chemical shifts in "C-NMR spectra. The assignments of ¹³C-NMR chemical shifts for (-)-lupinine [1] and (+)-epi-lupinine [6] were performed on the basis of offresonance decoupling, "C-H coupling constant, and comparison with results on other methylquinolidizines. The compound [1] afforded cis-methiodide [2] on quaternization with methyl iodide, whereas 6 J gave trans-methiodide t 7 J. The assignments of ¹³C-NMR chemical shifts for [2] and [7] were made by off-resonance decoupling and comparison with other data. On protonation of [1] with hydrochloric acid, an isomeric mixture of trans-salt [3a]and cis-salt [3 b] was formed in the ratio of ca.1: 1. On the other hand, [6] gave transsalt C8 on protonation with hydrochloric acid. ¹³C-NMR spectra for protonation products of [1] and 6 with sulfuric acid and picric acid were similar with those on protonation with hydrochloric acid. The probable reaction pathway for these reactions is presented in Fig.2.

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Reactions of vicinal dihalides [1a, c-f] with sodium sulfide in DMF at room temperature afforded halogen-free alkenes in good yields. Several 8-halo nitroalkanes [2a-f] were prepared and treated with sodium sulfide in DMF. β-Halo-β-(substituted phenyl)nitroalkanes [2c, d, g] gave α-haloalkenes[4c, d] or a-nitroalkene [5g]via the E 2-anti elimination mechanism. When [2 c, d, g] were allowed to react with mild reducing agents such as tin (II)chloride, amalgamated calcium, amalgamated sodium, and sodium dithionite, however, synchronous elimination of the nitro group and the halogen atom took place via the elimination radical chain (E_RC) mechanism to produce halogen- and nitrogen-free alkenes [3 c, d-f]. The reducing agents which gave [ 3] and [ 4] from 2 were found to belong to one-electron and two-electron reducing agents, respectively, generalized by Mathai et al.

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The reaction mechanism and rate-determing step (r. d. s. ) in the 1, 4-naphthoquinones (NQ) -Na₂S₂O₃ reaction systems have been examined by comparison of the oxidation-reduction potentials of NQ (ENQ) with the oxidation potential of Na₂S₂O₃ (E_ST). The addition of Na₂S₂O₃ to NQ proceeds as follows:
NQ + Na₂S₂O₃ + H ⁺ →1.2-Addition[I]→Prototropy[II]
The detection of stable intermediates [I] indicates the r. d. s. to be step ( 2 ) rather than step ( 1 ). This result differs from that in the p-benzoquinone (PQ)-Na₂S₂O₃ reaction system where the r. d. s. was step (1). This difference may be explained by the fact that the oxidation-reduction potential of PQ (E_PQ) is more positive than those of E_NQ. In the 2-methyl, 4-naphthoquinone (MNQ)-Na₂S₂O₃ reaction system the 3-position of the quinone ring is attacked, whereas in the MNQ-Na₂SO₃ reaction system the 2-position is attacked by Na₂SO3. This difference is caused by the fact that E?, NQ-EST is positive and E_XNQ-E_ss is negative.

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Syntheses of triarylmethanes by the condensation of N, N-dimethylaniline with aromatic aldehydes were studied by use of perfluorinated resin sulfonic acid (Nafion-H) catalyst in place of the commonly employed Brφnsted or Lewis acids. In a typical run, a mixture of N, N-dimethylaniline (3 mol) and aromatic aldehyde (1 mol) was heated at 150°C for 6 h in the presence of Nafion-H (E. W.1100). Optimum amount of the catalyst was 35 wt% to benzaldehyde for the production of Leucomalachite Green, and its yield reached to 78.4%. Similar condensations of N, N-dimethylaniline with various substituted benzaldehydes and naphthaldehydes produced also the corresponding triarylmethanes, where electron-withdrawing substituents in benzaldehydes favored the condensation. The Nafion-H catalyst could be used repeatedly, and the regenerated catalyst gave the same results as those by use of the fresh catalyst.
The reaction between N, N-dimethylaniline and benzaldehyde was followed by HPLC, and it was found that Leucomalachite Green was produced in a two-step manner via p-dimethylaminobenzhydrol.

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Red or yellow organic pigment with γ-alumina as a core was prepared by utilizing mechanochemical reaction. The method was as follows: By dry grinding the mixture of γ-alumina and aminobenzoic acids in a porcelain ball mill, aminobenzoic acids were introduced as aluminum salts in the active site appeared on broken face of γ-alumina. The organic groups on the surface of the ground sample were then derived to structures similar to sudan I [azo dyestuff, 1-phenylazo-2-naphthol] or tartrazine [Food Yellow No.4, trisodium salt of 5-hydrox1-(4-sulfopheny1)-4-(4-sulfophenylazo)-1 H-pyrazole-3-carboxylic acid] by diazotization and followed by coupling with 2-naphthol or 5-oxo-1-(4-sulfopheny1)-2-pyrazoline-3-carboxylic acid.
The mechanochemical reaction took place only between the active site of γ-alumina and carboxyl group of the aminobenzoic acid and not between γ-alumina and amino group. Aminobenzoic acids were not decomposed by the grinding. The prepared pigments had color similar to the corresponding sudan I (red) or aqueous solution of tartrazine (yellow).

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The isothermal heat treatment of polyacrylonitrile was carried out below 220°C for 1 h under a hydrogen chloride atmosphere. The treatment proved that hydrogen chloride takes hardly effect below 200°C but accelerates the rate of polymerization of cyano groups at 220°C (Figs.1 and 2). The acceleration was explained to result from the action of chlorine atom which was formed by the reaction of thermally degraded polymer radical with hydrogen chloride (Eqs. ( 1 ), ( 2 ), and ( 3 )). Moreover, differential thermal analysis (atmosphere: N2, heating rate: 5°C/min) was carried out for samples shown in Table 1 and acrylonitrile-α-chloroacrylonitrile copolymers. The results are shown in Figs.4 and 6. In all cases, the sharp exotherm due to polymerization of cyano groups appears at a higher temperature and the differential temperature becomes lower with increasing content of chlorine. This behavior seems to be closely associated with the polymerization of cyano groups which proceeds slowly on heating at 220-260°C (Fig.5). This progress of the polymerization also could be attributable to the action of chlorine atom as mentioned above.

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Bisphenol A diglycidyl ether was cured at 30°C with 1, 6-hexanediamine in the presence or abesence of salicylic acid as an accelerator. The curing process in these systems was monitored by measurements of the molecular weight and the functional groups in the products. The structures of the intermediates isolated from the cured resin using salicylic acid as an accelerator were also determined. The product of this accelerated system showed a high conversion of the secondary amino group. The intermediates having molecular weights in the range 340-1600 were isolated and their structure were estimated by means of GPC, VPO, NMR and titrational analyses. The molecular chain of the reaction products was suggested to be made of the alternating diepoxide and diamine units.

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The macroreticular chelating resins containing mercapto groups (RSS) were prepared by the reaction of chloromethylated styrene-divinylbenzene macroreticular copolymer (RSC) with potassium hydrogen sulfide. The adsorption behavior of metal ions on the RSS was investigated.
The introduction of mercapto groups into the RSC was effectively carried out by treatment of the RSC with ethanolic potassium hydrogen sulfide for 1 hour at 50°C. The RSS showed the selective adsorption ability for Ag⁺ and Hg²⁺ in the low pH region and good resistance against air oxidation. In the column method, the RSS exhibited a satisfactory adsorption ability for arsenic (III) when an aqueous solution containing 20 mg·dm^-3 of As (III), adjusted to pH 6.8, was passed through the column at the space velocity (SV) of 15 h^-1. The elution of arsenic(III) adsorbed on the RSS was accomplished by passing 1 mol·dm^-3 sodium hydroxide solution at the SV of 7.5h^-1. It was found that the RSS can be used for the recovery and removal of arsenic (III) in hot water (80-90°C).

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To inquire into the properties responsible for the reactivity of coal gasification and the effect of added CH₄ on the rate of steam gasification, char(C) and porous char (PC) prepared from the same parent coal were gasified with the mixtures composed of H₂O(0, 24%)-O₂(0, O.5, 3, 6%)-N₂ under atmospheric pressure at 600-950°C. The fuel ratio of six kinds of coals used here were in the range of 1.4 to 7.9. The gasification rate and the composition of product gas were investigated by an apparatus combined with a thermobalance and two gaschromatographs, using the 100 mg sample (average diameter: 0.5-2.0 mm, mainly 1.0 mm). The reactivity was evaluated quantitatively by applying the rate equation, f=1-exp(-aθ^b), (a, b =constants) to the data of fractional gasification (f) vs. time(θ).
Main results obtained were as follows: ( 1 ) Either N₂ or CO₂ were used as adsorbates to measure specific surface area(Sgo); in the former case the ratio of Sgo of PC to that of C were in the range of about 50 to 260, and in the latter case, of about 7 to 130. But the difference in the reactivity between PC and C showed only a few times at most, and there were almost no difference in the composition of product gas by steam gasification of PC and C.
(2) Activation energies of steam gasification of chars prepared from four parent coals were very close to that of pure porous carbon containing neither mineral matters nor ash.
(3) Low level CH₄ and/or H₂ mixed with steam showed a pronounced retarding effect on the rate of steam gasification. This was interpreted as the decreasing of surface complex, (OH)C, formed by dissociation of H₂O.
(4) The rate of gasification with H₂O (24%)-O₂(1%)-N, mixed with low level CH₄(3-6%) was almost close to that with O₂(1%)-N₂, and product gas was rich in CO and H₂ although methane was not consumed at all. This was interpreted well by the homogeneous radical chain oxidation scheme of CO and H₂.
(5) Steam gasification of char was chemically controlled at temperatures lower than about 1000°C. The pore size distribution and/or pore surface area gave almost no influence on gasification rate. The chemical properties of char surface and the chemical interaction between carbonaceous surface and gasifying H₂O molecule were seemed to be essentially predominant factors governing the reactivity of gasification of char.

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The photodecoloration reaction of nickel dithiobenzil complex having an absorption band in near infrared has been studied. The decoloration does not occur upon excitation with the near infrared light, but proceeds in two steps by irradiation with the UV light. In the first stage the photodecoloration rate increases with the increasing concentration of dissolved oxygen, but no such effect is observed in the second stage.

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A new wet metallurgy of CaWO, from middle to low quality scheelite ores was proposed. The alkaline hydrothermal extraction of WO₄^2- ion from the scheelite was investigated by using a microautoclave. Using an alkaline solution containing NaOH, Na₂CO₃ and Ca (OH)₂ high extraction ratios of WO₄^2- ions, above 90%, and low extraction ratios of SiO₃^2- ions, below 10%, were attained at 250°C for 5 min. The Si₃^2- ions mostly reacted with Ca (OH)₂to form insoluble orthosilicate (tobermorite).

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