Yuri N. Skiba and Denis M. Filatov
The purpose of this paper is to suggest a new approach to the numerical simulation of shallow‐water flows both in plane domains and on the sphere.
Abstract
Purpose
The purpose of this paper is to suggest a new approach to the numerical simulation of shallow‐water flows both in plane domains and on the sphere.
Design/methodology/approach
The approach involves the technique of splitting of the model operator by geometric coordinates and by physical processes. Specially chosen temporal and spatial approximations result in one‐dimensional finite difference schemes that conserve the mass and the total energy. Therefore, the mass and the total energy of the whole two‐dimensional split scheme are kept constant too.
Findings
Explicit expressions for the schemes of arbitrary approximation orders in space are given. The schemes are shown to be mass‐ and energy‐conserving, and hence absolutely stable because the square root of the total energy is the norm of the solution. The schemes of the first four approximation orders are then tested by simulating nonlinear solitary waves generated by a model topography. In the analysis, the primary attention is given to the study of the time‐space structure of the numerical solutions.
Originality/value
The approach can be used for the numerical simulation of shallow‐water flows in domains of both Cartesian and spherical geometries, providing the solution adequate from the physical and mathematical standpoints in the sense of keeping its mass and total energy constant even when fully discrete shallow‐water models are applied.
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Keywords
The post-Cold War period allowed the U.S. nuclear legacy of ecocide to be declassified and made public. The policy of nuclear secrecy, evident in Russia (see Mironova et al., this…
Abstract
The post-Cold War period allowed the U.S. nuclear legacy of ecocide to be declassified and made public. The policy of nuclear secrecy, evident in Russia (see Mironova et al., this volume), was not merely an eastern practice. Western nuclear releases were kept equally under wraps. In England, for example, the Windscale disaster was not fully disclosed until 1987.1 Likewise, releases from the Hanford Nuclear Reservation, in Washington State, and other U.S. nuclear sites were kept undercover until the same period. The irony was that Americans learned of many of the nuclear skeletons in their closet around the time that Russians learned of theirs (see Mironova et al., this volume). It would appear that glasnost was contagious.
Fan Yang, Jihui Wang, Changzeng Wang, Junlei Chen and Anxin Ding
In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.
Abstract
Purpose
In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.
Design/methodology/approach
In this work, a flame retardant with heterocyclic groups, HOMP, was acquired after removing the obstacle from triazines which was not readily soluble. The molecular structure, thermal and flame retardant properties were fully characterized and analyzed. Also, the mechanism was researched through multi-methodologies. As well, the authors evaluated the effects of HOMP on mechanical properties.
Findings
The results suggested that HOMP helped extinguish the combustion of specimens and could reach an LOI value of 29.2% and the V0 level in the UL-94 test with a phosphorus content of only 0.6wt%. With respect to the mechanism, HOMP was a gas-phase flame retardant and helped generate a thicker carbon protective coating. However, for the mechanical properties, the addition of HOMP enhanced the compressibility, while the tensile strength decreased significantly.
Originality/value
The approach not only simplified the operations but also obtained HOMP with excellent flame retardant properties.
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In both natural sciences and social sciences, there is relative agreement about the fact that the 20th century saw great diminishment of the earth's natural resources. In addition…
Abstract
In both natural sciences and social sciences, there is relative agreement about the fact that the 20th century saw great diminishment of the earth's natural resources. In addition to dwindling materials and space for human activities, our industrial mode of natural resource consumption brought various ecological problems, including waste, and pollution of water, soil, and air.1 The specifics of any given social system influence an individual's perception of pollution of the surrounding environment and its consequences, and also influence the reaction of a society in general to ecological problems. In other words, different societies develop different collective and individual strategies for coping with problematic situations related to “technogenic” pollution of the environment. This article, based as it is on an in-depth case study, analyzes the peculiar relationship of people to ecological issues in Russian society. Research was carried out in the city Dzerzhinsk, which, throughout the Soviet period, was proudly called the “Capital of Soviet Chemistry.” This city is thus a demonstrable example of the Soviet period, and the history of the city will serve as a lens through which we will analyze contemporary ecological problems of the city and the relations of its citizens to these problems. Dzerzhinsk was selected for study after it was described in newspapers as “the dirtiest (i.e., most polluted) city in Russia.”