Full scale investigation of GCL damage mechanisms in small earth dam retrofit applications under earthquake loading

This paper reports results of full scale testing to further explore potential GCL damage mechanisms in earth dam retrofit applications in seismically active areas; in particular, to a) investigate whether shear displacements could reduce the magnitude of GCL panel overlap during earthquake shaking; b) explore the influence of gravel particles on GCL thickness at localised point of contact; and c) observe the consequences of an accidental exposure of an uncovered GCL to short duration rainfall in terms of moisture content and effects during subsequent compaction. The results of these experiments indicate that even under severe shaking no movements were detected at the GCL panel overlap. Whereas gravel particles were observed to locally reduce the thickness of the GCL to 2.2 mm, no plowing of the particle into the GCL occurred due to a lack of shear displacement at the interface, resulting in no localised internal erosion through the barrier. Furthermore, hydration of GCL panels during construction due to surface wetting was observed to result in a state of hydration less than its post-construction state. These results indicate that although each of the three GCL damage mechanisms cannot be ruled out to ever be relevant in practice, the performance of the GCL retrofitted earth dam tested was satisfactory under even severe Level 2 earthquake shaking, and suggests that the retrofitting of small earth dams with GCLs is a promising strategy to improve their static and seismic resistance.     

Predicting Tensile Properties of Friction-Stir-Welded 6063 Aluminum with Experimentally Measured Welding Heat Input

This work aims to develop a reliable method to predict mechanical properties of friction-stir-welded 6 xxx-series alloys with experimentally measured welding heat input. A calorimetrical method was utilized to experimentally measure the welding heat input in the friction stir welded of aluminum alloy 6063-T5. Good correlations between the input variables, i.e., welding parameters and physical properties of the materials, and the welding heat inputs obtained with experimental measurements were discovered. The welding heat input can be predicted using the empirical equation derived based on these correlations. Moreover, the results suggested that the thermal conductivities of the welded alloys affected the welding heat input significantly. Mechanical properties, including hardness and tensile properties, of friction-stir-welded aluminum alloy 6063 were in good correlation to the heat input obtained with experimental measurement. These correlations were explained by the evolution of the strengthening precipitates during welding. This work proposed a reliable new route to predict these mechanical responses through the estimation of heat input.     

Endothelin ETB Receptor-Mediated Astrocytic Activation: Pathological Roles in Brain Disorders

In brain disorders, reactive astrocytes, which are characterized by hypertrophy of the cell body and proliferative properties, are commonly observed. As reactive astrocytes are involved in the pathogenesis of several brain disorders, the control of astrocytic function has been proposed as a therapeutic strategy, and target molecules to effectively control astrocytic functions have been investigated. The production of brain endothelin-1 (ET-1), which increases in brain disorders, is involved in the pathophysiological response of the nervous system. Endothelin B (ET_B) receptors are highly expressed in reactive astrocytes and are upregulated by brain injury. Activation of astrocyte ET_B receptors promotes the induction of reactive astrocytes. In addition, the production of various astrocyte-derived factors, including neurotrophic factors and vascular permeability regulators, is regulated by ET_B receptors. In animal models of Alzheimer’s disease, brain ischemia, neuropathic pain, and traumatic brain injury, ET_B-receptor-mediated regulation of astrocytic activation has been reported to improve brain disorders. Therefore, the astrocytic ET_B receptor is expected to be a promising drug target to improve several brain disorders. This article reviews the roles of ET_B receptors in astrocytic activation and discusses its possible applications in the treatment of brain disorders.     

关于城市的变异

面对仓促巨变的亚洲城市的严峻现实，设计者，包括建筑师、规划师和艺术家们，试图将个体的主张有效的介入城市生活，应对复杂的城市问题。作为2002上海双年展的策展人，作者介绍了由她推荐的十个艺术家和建筑师的作品。     

The Fe3O4-formation by the ‘Ferrite Process’: Oxidation of the reactive Fe(OH)2 suspension induced by sucrose

A mechanism of the formation of small particles of iron oxide in the wastewater treatment system ‘Ferrite Process’ is described. Small particles consisting of the Fe₃O₄−γ-Fe₂O₃ solid solution having slightly higher content of γ-Fe₂O₃ were obtained by the aerial oxidation of Fe(OH)₂ suspension in the presence of a weak dispersing reagent, sucrose, at pH 9.0. The increase of γ-Fe₂O₃ content is caused by a further oxidation of the Fe₃O₄ particles in the course of the reaction. The further oxidation was accelerated below 1000 Å of the particle size. When SO²⁻₄ ion coexisted with sucrose in the reaction medium, the further oxidation was reduced and the treatment of the wastewater was improved. At a temperature interval of 40°–65°C, the formation of α-FeOOH was completely inhibited by a small amount of sucrose and only Fe₃O₄ was obtained.