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A Study of Heat Damage to Hair and How to Indicate Heat Damage
Abstract
Hair styling by heat treatment with a hair iron or curling iron has been frequently done. However, heat treatment causes much hair damage. In this work, we have studied heat damage and how to indicate heat damage. The change of cystine into lanthionine moieties of hair protein occurs with heat treatment. So, we checked whether the amount of lanthionine in hair could serve as an effective heat damage index. As a result, while the amount of cysteic acid was increased by bleach treatment and permanent treatment, the amount of lanthionine was increased by heat treatment. Additionally, we found the degradation of both moisturizing effect and physical strength of hair. Based on these, we concluded that the measurement of lanthionine in the hair was effective to indicate the heat damage to hair.
... However, chocolate kept in the backpack of a person in Hatchotarumi melted, and a part of his hair was discolored. The melting temperature of typical chocolate is approximately 30 °C and that of the discolored part of hair is >100 °C in hot air (e.g., Yamashita et al. 2012). The estimated temperature of the PDCs accompanying the eruption was higher than or equal to that of the 2012 eruption of Te Maari Volcano (100-64 °C in proximal, 51-58 °C in distal: Efford et al. 2014), and lower than that of the 1900 eruption of Adatara Volcano (over 100 °C, under 400 °C: Fujinawa et al. 2006). ...
A phreatic eruption at Mount Ontake (3067 m) on September 27, 2014, led to 64 casualties, including missing people. In this paper, we clarify the eruption sequence of the 2014 eruption from recorded images (photographs and videos obtained by climbers) and interviews with mountain guides and workers in mountain huts. The onset of eruption was sudden, without any clear precursory surface phenomena (such as ground rumbling or strong smell of sulfide). Our data indicate that the eruption sequence can be divided into three phases. Phase 1: The eruption started with dry pyroclastic density currents (PDCs) caused by ash column collapse. The PDCs flowed down 2.5 km SW and 2 km NW from the craters. In addition, PDCs moved horizontally by approximately 1.5 km toward N and E beyond summit ridges. The temperature of PDCs at the summit area partially exceeded 100 °C, and an analysis of interview results suggested that the temperature of PDCs was mostly in the range of 30-100 °C. At the summit area, there were violent falling ballistic rocks. Phase 2: When the outflow of PDCs stopped, the altitude of the eruption column increased; tephra with muddy rain started to fall; and ambient air temperature decreased. Falling ballistic rocks were almost absent during this phase. Phase 3: Finally, muddy hot water flowed out from the craters. These models reconstructed from observations are consistent with the phreatic eruption models and typical eruption sequences recorded at similar volcanoes.
Bis-ethoxydiglycol cyclohexane 1,4-dicarboxylate (BECD), a water-and oil-soluble ester oil, contains hydrophilic (oxyethylene chain) and hydrophobic (cyclohexane ring) groups on the same molecule. The wavy hair undulation relaxed, and its restoration after 24 h was suppressed when wavy hair soaked in the BECD aqueous solution was hand-straightened and dried with a hair dryer. BECD was adsorbed on the non-keratin proteins, and straightening and drying wet wavy hair with a hair dryer caused BECD to easily promote the contraction and rearrangement of the elongated and deformed molecular chains and promote the homogenization of the aggregate structures of the non-keratin proteins, thereby relaxing undulation. Wavy hair not treated with BECD does not undergo uniform contraction or rearrangement of the molecular chains of the non-keratin proteins during the glassification process involving hair being straightened from wet conditions and finger-dried. This results in variations in the morphology of the aggregated structure of the non-keratin tissue, resulting in undulation. Contrastingly, the contraction and rearrangement of the constituent molecular chains of the non-keratin protein proceeded easily in the BECD-treated wavy hair, and the homogenization of the aggregated structure was promoted, which is thought to suppress undulation. The molecular mobility and moisture absorption characteristics of wavy hair were reduced after drying, and only slight contraction and rearrangement occurred over time. This may have inhibited the wavy hair from returning to its original state.
Applied Polymer Symposium No
- R S Asquith
- M S Otterburn