Electron correlations in charge transfer complexes consisting of organic donor/acceptor molecules with their counter ions play an important role for realizing various kinds of ground states. Among numerous compounds, those classified as the dimer-Mott system such as κ-type and β'-type 2:1 complexes give a conducting/superconducting phase and a Mott insulating phase due to the difference of U/W ratio. In the conducting region, unconventional superconductors with T_c ≈ 10 K class appear at low temperatures. In order to cultivate new features and to verify the mechanism of them, we constructed several calorimetry systems for measuring heat capacity by small amount of samples with varying temperatures, magnetic fields and external pressures. The systematic heat capacity measurements of the superconductive phase revealed that the pairing symmetry is anisotropic d-wave accompanied by line-node gap structures. The angle resolved heat capacity measurements with in-plane magnetic fields detected a clear four-fold modulation of the electronic heat capacity coefficient. The importance of the antiferromagnetic spin fluctuations for pair formation is strongly suggested. In the dimer-Mott triangle lattice compounds, a spin liquid-like feature was observed from the analyses of low temperature heat capacity data under magnetic fields. The advantages of the heat capacity measurements to clarify the phase relations and to detect low energy excitations from the ground states are emphasized.

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This paper describes the application of thermal analysis in research and development of sodium-cooled fast reactor (SFR). In a SFR, the sodium-concrete reaction (SCR) should be considered when a hypothetical accidental condition such as the steel liner failure by leakage of liquid sodium (Na) was assumed. The major consequences of SCR are hydrogen release, energy release and concrete ablation. Thus, it is important to understand the phenomenology and kinetic behavior of SCR. As model reactions of SCR, reactions of sodium and sodium compounds with silica were studied using thermal analysis. Differential scanning calorimetry (DSC) equipped with a videoscope for in-situ observations of the reacting samples was successfully used for revealing the phenomenological features of the model reactions. Further, the kinetic features of the reactions were analyzed from DSC curves using the conventional kinetic calculation method, known as Kissinger method. Subsequently, the significance of the calculated kinetic parameters obtained for each model reaction was evaluated through the kinetic deconvolution analysis for the overlapping multi-step processes. The practical meanings of the kinetic parameters determined using the conventional kinetic analysis were discussed for utilizing these for the relative estimation of the reactivity and for the simulation of the overall behavior under real conditions.

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Thermal technique has been widely used for thermal hazard analysis of chemical substances and safety management of chemical processes. In this paper, thermal hazard of cumene hydroperoxide with cumene solvent is experimentally analyzed with DSC, Calve-type heat flux calorimeter and high sensitivity thermal activity monitor, and the thermal decomposition mechanism is investigated with Raman spectroscopic analysis. Further, thermal risk diagram of chemical process is shown and layer of protection analysis is described.

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In order to understand and to propose a countermeasure for fires caused by accumulations of a huge amount of disaster waste (rubble), thermogravimetry -differential thermal analysis, high sensitivity calorimetry and gas chromatography were performed. It was found that the small heat generation by fermentation was one of triggers of the fire. We concluded that fermentation inside domestic waste, such as rotten tatami has the highest potential for the spontaneous combustion.

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Safe decontamination combustion system for forestry and agricultural waste including radiocesium, caused by Fukushima Nuclear Power Plant accident, was developed and the demonstration combustion test of contaminated forestry wastes was carried out. Thermal decomposition behaviors of contaminated biomass, cedar leaves, bark, sapwood and pine leaves were investigated by TG/DTA-FTIR. The laboratory scale combustion test of contaminated cedar bark (10 g) was carried out at 300 – 900 ºC. Mass and radiocesium balances were evaluated, 30 – 35 % of radiocesium in bark evaporated by combustion above 500 ºC. Gaseous radiocesium was trapped efficiently by water. The mass and radiocesium balances of demonstration test for contaminated forestry waste (6 kg) were evaluated. 95 % of radiocesium in contaminated forestry wastes was retrieved by combustion gas extraction and ash.

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