Numerical analysis model of galvanic corrosion in consideration of ion movement and reactions

We have developed a new numerical analysis model for galvanic corrosion that can calculate ions movement,reactions and electroneutrality. In this model, major species and reactions were considered, and ion density distributionis corrected by solving Poisson's equation to satisfy electroneutrality. Reactions are calculated basedon chemical equilibrium. Galvanic corrosion of a Fe/Zn couple in a NaCl, MgCl2 solutions and artificial seawater was calculated by this model. The distributions of pH, ion density and corrosion products were discussedin these solutions. The distributions of corrosion product obtained by the numerical analysis model agreedwell with those measured by FT-IR method qualitatively. In 500ppm NaCl solution, Zn(OH)2, ZnCl2/6Zn(OH)2and ZnCO3 were precipitated on the Zn and near the Fe/Zn interface, while there were little precipitations onthe Fe far from the Fe/Zn interface. On the other hand, Mg(OH)2 was precipitated on the Fe in 500ppm MgCl2solution and 1/100 artificial sea water. Mg(OH)2 may contribute to corrosion protection of the Fe in the solutionincluding Mg2+. It is noted that Mg(OH)2 can be precipitated only in the cathodically protected area becausethe solubility product constant of Mg(OH)2 is larger than that of Fe(OH)2

The phenology of epiphytic diatoms and epifauna observed on Zostera marina of Arikawa Bay, Nagasaki Prefecture, Japan

We present a descriptive account of the dynamics of epiphytic diatoms, epifauna, and the leaf surface area of Zostera marina in a shallow water ecosystem. We hypothesized that the growth stage of the host macrophyte (i.e., leaf surface area) influenced the presence of epiflora and epifauna, as well as that the leaf surface area and epifaunal population density affected the cell density and species composition of epiphytic diatoms. To evaluate this hypothesis, we quantified the leaf surface area of a host macrophyte (Zostera marina), the presence of epifauna, and the community of epiphytic diatoms that could be observed on the leaves of Z. marina during the period from May 2017 to December 2018. We conducted a descriptive analysis of the time-series observations of leaf surface area, epiphytic diatom density, and epifauna population density. Epiphytic diatom density was low and epifauna density was high during the growing season of Z. marina. Epiphytic diatom density was high and epifauna density was low during the maturation and senescence periods of Z. marina. Our analysis shows that epifauna densities lagged epiflora densities by at least four months, and that epiflora densities lagged leaf area by four months. Therefore, we hypothesized that herbivorous gastropods and amphipods could alter species composition via their preference of food items (active choice) or by ingesting more of the species that were structurally more available (passive preference)

Development of x-ray emission computed tomography for ICF research

Copyright 1990 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 61(10), 2763-2785, 1990 and may be found at http://dx.doi.org/10.1063/1.114183

Three Dimensional Relativistic Electromagnetic Sub-cycle Solitons

Three dimensional (3D) relativistic electromagnetic sub-cycle solitons were observed in 3D Particle-in-Cell simulations of an intense short laser pulse propagation in an underdense plasma. Their structure resembles that of an oscillating electric dipole with a poloidal electric field and a toroidal magnetic field that oscillate in-phase with the electron density with frequency below the Langmuir frequency. On the ion time scale the soliton undergoes a Coulomb explosion of its core, resulting in ion acceleration, and then evolves into a slowly expanding quasi-neutral cavity.Comment: 5 pages, 6 figures; http://www.ile.osaka-u.ac.jp/research/TSI/Timur/soliton/index.htm

A system of relational syllogistic incorporating full Boolean reasoning

We present a system of relational syllogistic, based on classical propositional logic, having primitives of the following form: Some A are R-related to some B; Some A are R-related to all B; All A are R-related to some B; All A are R-related to all B. Such primitives formalize sentences from natural language like `All students read some textbooks'. Here A and B denote arbitrary sets (of objects), and R denotes an arbitrary binary relation between objects. The language of the logic contains only variables denoting sets, determining the class of set terms, and variables denoting binary relations between objects, determining the class of relational terms. Both classes of terms are closed under the standard Boolean operations. The set of relational terms is also closed under taking the converse of a relation. The results of the paper are the completeness theorem with respect to the intended semantics and the computational complexity of the satisfiability problem.Comment: Available at http://link.springer.com/article/10.1007/s10849-012-9165-

Experimental Evidence for a Glass forming "Stripe Liquid" in the Magnetic Ground State of La1.65Eu0.2Sr0.15CuO4

We report measurements of the longitudinal ($^{139}T_1^{-1}$) and transverse ($^{139}T_2^{-1}$) decay rates of the magnetization of $^{139}$La nuclei performed in a high quality single crystal of La$_{1.65}$Eu$_{0.2}$Sr$_{0.15}$CuO$_{4}$. We observe a dramatic slowing of the Cu 3d spins manifested as a sharp increase of both $^{139}T_1^{-1}$ and $^{139}T_2^{-1}$ below 30 K. We find that in this temperature range the fluctuations involve a unique time scale $\tau$ which diverges as $(T-T_{\rm A})^{-1.9}$ with $T_{\rm A}\thickapprox 5$ K. This behavior is distinct from the continuous freezing observed in underdoped La$_{1-x}$Sr$_x$CuO$_4$ which involves a distribution of energy barriers. By contrast, in La$_{1.65}$Eu$_{0.2}$Sr$_{0.15}$CuO$_{4}$, the freezing below 30K is intrinsic to its magnetic ground state and the observed power law supports the existence of a glass forming "charge stripe liquid".Comment: 5 pages, 3 Figures. Revised version, resubmitte