https://hal.archives-ouvertes.fr/hal-00858028/document

Large-scale 3D random polycrystals for the finite element method: Generation, meshing and remeshing

Removal mechanisms for endocrine disrupting compounds (EDCs) in wastewater treatment — physical means, biodegradation, and chemical advanced oxidation: A review

Computer simulation of 3-D grain growth using a phase-field model

This review covers recent advances in the study of foam drainage and coarsening, focusing especially on the effective role of the foam chemical components on those aging processes. The determination of the relevant parameters controlling foam drainage and coarsening today remains a major issue: are the physical parameters (like bubble size and liquid fraction) sufficient to define a foam and to predict its evolution, or do the chemical components also matter? And if these foam components are important, one has to determine by which mechanisms, and which microscopic parameters involved in these mechanisms are eventually crucial. I report here recent experimental results, shedding light on these issues. It allows us to summarize how the surfactant, the liquid bulk properties, and the gas modify or not the drainage and coarsening features. The coupling between drainage and coarsening is also discussed, as well as the role of the experimental conditions (sample height, shape or foam uniformity).

https://perso.univ-rennes1.fr/arnaud.saint-jalmes/review_saintjalmes_drainage_coarsening_final.pdf

Physical chemistry in foam drainage and coarsening

A framework for automated analysis and simulation of 3D polycrystalline microstructures.: Part 1: Statistical characterization

Three-dimensional microstructural evolution in ideal grain growth—general statistics

Molecular dynamics simulation of polycrystalline material has been carried out to investigate the atomic structure of grain boundary. We developed a simple method for expressing and analyzing the polycrystalline structure involving various grain sizes by introducing weighted Voronoi polyhedra. The three dimensional simulation exemplified by zirconia nanocrystals showed that the model structure is stable at elevated temperatures up to near the melting point. The feasibility of the present method was tested by analyzing the structure properties of polycrystalline, based on the mathematical expressions describing the grain boundary and inside grain regions.

Molecular Dynamics Simulation of the Model Grain Boundary Structure of Polycrystalline Materials

下水処理施設や合併処理浄化槽の流入水中に含まれている外因性内分泌攪乱化学物質 (EDC) について、実績濃度値から添加条件を設定し、活性汚泥及び嫌気性汚泥による生分解試験を試みた。17 β-エストラジオール (E2) は反応開始直後に90%以上が活性汚泥に吸着され、反応開始後72時間で定量下限値未満 (N.D.) まで低下した。ビスフェノールA (BPA) 及びノニルフェノール (NP) もMLSS濃度が高いほど汚泥に吸着され、生分解率はBPAが72～99%、NPが59～90%であり、これらEDCの生分解反応は1次反応に従うことが明らかとなった。一方、嫌気性汚泥による生分解試験では、E2、BPA及びNPの分解がほとんど認められなかった。また、フタル酸エステル類 (PAE) のうち、フタル酸ジ-2-エチルヘキシル (DEHP) 及びフタル酸ジ-n-ブチル (DBP) の好気性分解試験では、分解の進行に伴い、中間代謝物としてフタル酸モノエチルヘキシル (MEHP)、フタル酸モノブチル (MBP)、さらに、フタル酸 (PA) の生成が確認された。

Biodegradation of Endocrine Disrupting Chemicals in Aerobic and Anaerobic Sludges

This paper describes the simulated atomistic process in a large deformation of polycrystalline matter. Molecular dynamics method was applied to a model polycrystal of yttria-stabilized zirconia composed of eight small grains to investigate the microscopic mechanism of superplastic deformation. During the tensile deformation up to the strain of 0.55, a neighbor-switching event of grains similar to that proposed by Ashby and Verrall was observed in the present simulation. The large strain was accomplished by non-uniform diffusional flows in the polycrystal. By analyzing the diffusive motions of oxide ions, the mass transport during the deformation was found to take place mainly in the boundary layer of about 1 nm thickness, which covers about 0.4 times of the total volume. This result is different from the quasi-uniform flow expected in the classical creep models, but is consistent with the Ashby and Verall's model.

Atomistic Simulation of a Neighbor-Switching Event in the Deformation of a Model Polycrystal

As more than 90 % of the installed Gappei-shori Johkasous, a kind of domestic wastewater treatment plant, are made of fiber-glass reinforced plastics (FRP) or dicyclopentadiene (DCPD), there is an environmental risk resulting from the elution of bisphenol A (BPA) and phthalic acid ester from such johkasous. A study on elution of the endocrine disrupting chemicals from FRP/DCPD-made johkasous was carried out using test-piece of the johkasous and a johkasou in operation.The results showed that di- (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) was detected in the elution experiment, implying that those endocrine disrupting chemicals eluted into the water from the test-piece and the johkasou in operation. However, DEHP and DBP in water seem to be adsorbed by activated sludge, and then DEHP and DBP were biodegradated in the activated sludge. The residual rates of DEHP and DBP after 30 days was found to be 28%, 33% respectively.

Hiroshi Ogawa

Papers

Three-dimensional microstructural evolution in ideal grain growth—general statistics

Molecular Dynamics Simulation of the Model Grain Boundary Structure of Polycrystalline Materials

Biodegradation of Endocrine Disrupting Chemicals in Aerobic and Anaerobic Sludges

Atomistic Simulation of a Neighbor-Switching Event in the Deformation of a Model Polycrystal

Elution and Behavior of Endocrine Disrupting Chemicals from FRP or DCPD-made Gappei-shori Johkasous