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Thoughts on Journalism as an “Institutional Practice” in Modern Japan
Full text linkdepartmental bulletin pape
Boulder Surface Features and Its Thermal Environment Coated by Rock Varnish at Burrup Peninsula, Western Australia
Full text linkIn the arid environment of Burrup Peninsula, Western Australia, numerous instances of flaking can be observed on
varnished boulder surfaces. While the formation processes of rock varnish have been extensively studied, the relation
ship between flaking and thermal fracturing remains relatively unexplored. This study investigates the flaking phenome
non on gabbro boulders at the Peninsula, analyzing its color, hardness, and rock surface temperature in relation to ther
mal fracturing.
The results suggest that the varnish on the boulders is primarily composed of hematite, imparting a reddish-brown
hue. The hardness of the varnished surface is significantly lower than the unweathered interior, indicating a lack of case
hardening. Under the harsh arid conditions, the boulder surface experiences extreme temperature fluctuations, with a
maximum of ≥61℃ and a diurnal temperature difference of 46℃. Rapid temperature changes, driven by factors like cloud
cover and rainfall, can reach rates of ＋1.3℃/min and －1.5℃/min. Despite these severe conditions, the boulders have
not experienced thermal shock fracturing, suggesting the involvement of more complex thermal weathering processes,
such as thermal fatigue, which arises from a subcritical crack growth due to the long-term effects of low-magnitude, cyclic
thermal loading.departmental bulletin pape
Temporal and Spatial Variation for Magmatic Systems of the Late Quaternary Caldera Complex of Southern Kyushu Viewed from the Whole-rock Chemistry of Large-scale Eruptive Pyroclastic Products
Full text linkThe spatial and temporal variations of major, trace and REE whole-rock chemical compositions for the large-scale
eruptive pyroclastic products of late Quaternary large-scale calderas in southern Kyushu are examined; they are the
Kakuto pyroclastic density current (PDC) deposit (0.34 Ma) from the Kakuto caldera, the Iwato PDC, Osumi pyroclastic
fallout and Ito (0.03 Ma), and Moeshima (0.013 Ma) PDC deposits from the Aira caldera, the Ata (lower and upper) (0.11
Ma) and Imaizumi (0.10 Ma) PDC deposits from the Ata north caldera, and the Torihama (0.24Ma) PDC and Ikeda
(0.0064 Ma) PDC deposits from the Ata south caldera. On the basis of chemical compositions, the Iwato PDC and Osumi
pyroclastic fallout and Ito PDC deposits belong to the same magmatic system which is different from that of the Moeshi
ma PDC deposit; the lower unit of Ata PDC deposit was erupted from the different magmatic system from those of the
upper unit of Ata PDC deposit which was derived from the same magmatic system as the Imaizumi PDC deposit; the Tori
hama and Ikeda PDC deposits from the Ata south caldera were not erupted from the same magmatic system. The incom
patible and REE compositions and their ratios such as K2
O, TiO2
P2
O5
, Rb, Ba, Zr, Y and Nb contents, and Rb/Y, Rb/Zr,
Rb/Nb, Rb/Ba, Ba/Y, Ba/Zr, Ba/Nb, Zr/Y, Nb/Y, Nb/Zr, La/Yb and Ce/Yb ratios of these large-scale PDC deposits from
each caldera vary in space and time; e.g. K2
O, Rb and Ba decrease from north to south along the Kagoshima graven. It is
difficult to produce the felsic magma of each large-scale PDC deposit by simple crystallization differentiation from a sin
gle parental magma; the chemistry of source material for each magma of large-scale PDC deposit is various and changes
spatially and temporally.departmental bulletin pape
Désir, société et personne dans L’Anti-OEdipe : l’asservissement dans la liberté et la liberté dans l’asservissement
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Pragmatics in Roman Law Texts: Application of Speech Act Theory to the Verb Quaero in Justinianus’s Digesta
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