Mieko Kumasaki

Calorimetric behaviors of hydroxylamine and its salts caused by Fe(III)

Abstract The objective of this study is to obtain information on the calorimetric behaviors of aqueous solutions of hydroxylamine (HA), hydroxylamine chloride (HACl), and hydroxylamine nitrate(HAN) caused by different Fe(III) states (free Fe(III) from Fe(NH 4 )(SO 4 ) 2 , Fe(CN) 6 3− , and Fe(EDTA) − ). The calorimetric data were obtained with a small-scaled reaction calorimeter, Super-CRC. In the mixing with Fe(III), HA showed the highest reactivity among three substrates. Free Fe(III) and Fe(EDTA) − showed catalytic effects in the reactions. In the overall heat of reactions, Fe(EDTA) − exceeded free Fe(III), which precipitated as Fe(OH) 3 and decreased the chances of interactions with HA. It was suggested that the generation of NH 3 had taken place in the process of reducing HA along with Fe(II) oxidation. Fe(CN) 6 3− was less reactive than free Fe(III) and Fe(EDTA) − . The ability of masking Fe(III) was estimated for CyDTA. The HA including CyDTA had no exothermic peak; however, there was an endothermic peak of the heat flow at Fe(III) injection. CyDTA was found to have the ability to inhibit a violent exothermic reaction of HA.

Anatomy of cascading natural disasters in Japan: main modes and linkages

In order to contribute to the development of risk assessment, cascading natural disasters which are sequences of natural hazards was studied, and the patterns of the interactions between natural disasters were investigated. The data were collected from the database of Japanese newspaper. The relationships between each natural hazard were emerged and divided into four modes: striking, undermining, compounding, and blocking modes. Striking mode means a primary disaster provides sufficient energy to move a significant mass or to propagate the energy through media. In undermining mode, a primary disaster lowers the resistance or weakens a system maintaining mass and causes to collapse. Compounding mode of the linkage shows that a primary disaster reduces the strength of a system. Its difference from undermining mode is that this mode adds to the amount of mass affected. Blocking mode is found in an event blocking steady flows. The results are important for understanding of the impact of these types of cascading natural disaster and so are valuable as a basis for the identification, description, and development of countermeasures.

Influence of deteriorated solvent on induction period of Grignard reagent formation

The influence of a degraded solvent on Grignard reagent formation was investigated in terms of heat release behaviour. Since degraded solvent is supposed to contain peroxide by oxidation with air as well as water from atmosphere, peroxide in this study was intentionally produced by the storage of tetrahydrofuran in a pressurized oxygen atmosphere and the induction periods were measured. The induction period which appears prior to the main exothermic reaction increased with increasing amounts of peroxide and water content, respectively. However, there was a difference in heat release behaviour; the reaction including peroxide showed a delay in the heat release and two exothermic peaks, while the solvent that included water simply showed a delay in the start of the reaction. γ-Butyrolactone was found to be a product derived from peroxide, by component analysis of the oxidized solvent. γ-Butyrolactone caused an induction period when it was added to the solvent. This work suggests a deteriorated solvent can lead to inappropriate handling which cause a runaway reaction and gives insight to the chemical industry that manages the risk of potentially hazardous chemical reactions.

Thermal sensitivities of triazole derivatives and dinitrobenzene mixtures from the perspective of charge transfer

Energetic material mixtures can be considered as the blends of fuel and oxidizing agents that release energy during redox reactions; therefore, the relationship between their thermal sensitivity and the electrostatic interactions between the electron donor (reductant) and electron acceptor (oxidant) in such mixtures was investigated as an indicator to enable prediction of the thermal sensitivity. The donor–acceptor interactions were evaluated for the mixtures of triazole derivatives and dinitrobenzene by assessing the differences between the ionization energy of the donor and the electron affinity of the acceptor to quantify the magnitudes of the interactions. The ionization energy was experimentally determined by using photoemission yield spectroscopy in air, which determines the photoemission yield as a function of the energy of the ultraviolet irradiation, and theoretically determined using molecular orbital calculations. The thermal sensitivities of the mixtures were evaluated using differential scanning calorimetry. The thermal sensitivities of the mixtures increased as the difference between the ionization energy of the donor and electron affinity of the acceptor increased. A good correlation between the thermal sensitivity and this difference was observed, particularly in the experimental data. The magnitude of the donor–acceptor interactions may thus serve as a potential indicator of the thermal sensitivities of energetic material mixtures.

Risk assessment of potential gas odorants for the storage process

Abstract1-pentyne and 2-hexyne were assessed as replacements for sulphur-bearing odorants in fuel gases, particularly in the view of thermal risks associated with the storage of sulphur-bearing odorants. Both the alkynes were inactive when heated under pressurised nitrogen, but their exothermic behaviour and pressure profiles were found to change when heated in contact with pressurised air. The pressure profiles were considered based on the consumption of oxygen. The exothermic behaviours of 1-pentyne and 2-hexyne were compared both before and after the storage process using differential scanning calorimetry. While both species showed two exothermic peaks before storage, the thermal and pressure load applied during the storage process increased the heat released at low temperatures. Storage under pressurised air influenced the stability of the both the species as well as their exothermic behaviour. The results will help in the use of these odorants and safe handling of fuels containing them.

A Logical Hazard Identification Method in Workplace

The quality of hazard identification has a significant impact on the quality of overall risk assessment and occupational accident prevention in workplace. Currently accepted hazard identification approaches tend to rely on knowledge of previous accidents, experience of the task, and participants’ imagination, although hazard identification itself is most important for new tasks and novices who do not have experiences of the same or similar tasks. This paper outlines a logical hazard identification method based on a concept for object-based energy analysis as a tool that does not require experience, knowledge of tasks, or imagination. The method is derived from a physical principal and the analysis of occupational accidents. This method is expected to enable users to identify hazards effectively and easily, and contribute to successful risk assessment.

Lessons learned by the strong local earthquake at the petrochemical plant

Lessons Learned by the Strong Local Earthquake at the Petrochemical Plant Yuji Wada, Masahide Wakakura, Yuji Hayashi, Nobuo Takagi, Hiroyuki Oba, Mieko Kumasaki, Atsumi Miyake, and Mitsuru Arai Research Institute of Science for Safety and Sustainability (RISS), National Institute of Advanced Industrial Science and Technology (AIST), AIST West Site, 16-1 Onogawa, Tsukuba, 305-8569, Japan Chiyoda Corporation, 2-12-1 Tsurumichuo, Tsurumi-ku, Yokohama, 230-8601, Japan System Safety Laboratory, 1279-18 Bukkocho, Hodogaya-ku, Yokohama, 240-0044, Japan Kureha Corporation, 3-32 Nihonbashi-Hamacho, Chuo-ku, Tokyo, 103-8552, Japan Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan yuji.wada@aist.go.jp