Thermo-oxidative Oligomerization of Aromatic Diamine

Molecular spectroscopy (electronic, FT-IR, NMR), methods of thermal and elemental analysis were used for the first time to describe the process of thermo-oxidative oligomerization of 1,3-bis-(4-aminophenoxy)benzene. Introduction of this monomer into linear and network copolymers makes it possible to improve processability, mechanical strength and heat resistance of materials. The structures of copolymers obtained by thermo-oxidation of the diamine in various thermal regimes were studied. It was demonstrated that during prolonged heating of this diamine in air in the temperature range from 220 to 320°C, oligomeric aromatic diamines were formed; these products contained fragments of benzenoid and quinoid types

A unified approach to energy conservation and potential vorticity dynamics for arbitrarily-structured C-grids

Copyright © 2010 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Computational Physics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Computational Physics, Vol. 229, Issue 9 (2010), DOI: 10.1016/j.jcp.2009.12.007A numerical scheme applicable to arbitrarily-structured C-grids is presented for the nonlinear shallow-water equations. By discretizing the vector-invariant form of the momentum equation, the relationship between the nonlinear Coriolis force and the potential vorticity flux can be used to guarantee that mass, velocity and potential vorticity evolve in a consistent and compatible manner. Underpinning the consistency and compatibility of the discrete system is the construction of an auxiliary thickness equation that is staggered from the primary thickness equation and collocated with the vorticity field. The numerical scheme also exhibits conservation of total energy to within time-truncation error. Simulations of the standard shallow-water test cases confirm the analysis and show convergence rates between 1st1st- and 2nd2nd-order accuracy when discretizing the system with quasi-uniform spherical Voronoi diagrams. The numerical method is applicable to a wide class of meshes, including latitude–longitude grids, Voronoi diagrams, Delaunay triangulations and conformally-mapped cubed-sphere meshes

Ocean model resolution dependence of Caribbean sea-level projections

Abstract Sea-level rise poses severe threats to coastal and low-lying regions around the world, by exacerbating coastal erosion and flooding. Adequate sea-level projections over the next decades are important for both decision making and for the development of successful adaptation strategies in these coastal and low-lying regions to climate change. Ocean components of climate models used in the most recent sea-level projections do not explicitly resolve ocean mesoscale processes. Only a few effects of these mesoscale processes are represented in these models, which leads to errors in the simulated properties of the ocean circulation that affect sea-level projections. Using the Caribbean Sea as an example region, we demonstrate a strong dependence of future sea-level change on ocean model resolution in simulations with a global climate model. The results indicate that, at least for the Caribbean Sea, adequate regional projections of sea-level change can only be obtained with ocean models which capture mesoscale processes.info:eu-repo/semantics/publishe

A tsunami generated by a strike-slip event.: constraints from GPS and SAR data on the 2018 Palu earthquake

A devastating tsunami struck Palu Bay in the wake of the 28 September 2018 Mw = 7.5 Palu earthquake (Sulawesi, Indonesia). With a predominantly strike-slip mechanism, the question remains whether this unexpected tsunami was generated by the earthquake itself, or rather by earthquake-induced landslides. In this study we examine the tsunami potential of the co-seismic deformation. To this end, we present a novel geodetic dataset of GPS and multiple SAR-derived displacement fields to estimate a 3D co-seismic surface deformation field. The data reveal a number of fault bends, conforming to our interpretation of the tectonic setting as a transtensional basin. Using a Bayesian framework, we provide robust finite fault solutions of the co-seismic slip distribution, incorporating several scenarios of tectonically feasible fault orientations below the bay. These finite fault scenarios involve large co-seismic uplift ( > 2 m) below the bay due to thrusting on a restraining fault bend that connects the offshore continuation of two parallel onshore fault segments. With the co-seismic displacement estimates as input we simulate a number of tsunami cases. For most locations for which video-derived tsunami waveforms are available our models provide a qualitative fit to leading wave arrival times and polarity. The modeled tsunamis explain most of the observed runup. We conclude that co-seismic deformation was the main driver behind the tsunami that followed the Palu earthquake. Our unique geodetic dataset constrains vertical motions of the sea floor, and sheds new light on the tsunamigenesis of strike-slip faults in transtensional basins

A Tsunami Generated by a Strike-Slip Event: Constraints From GPS and SAR Data on the 2018 Palu Earthquake

A devastating tsunami struck Palu Bay in the wake of the 28 September 2018 Mw = 7.5 Palu earthquake (Sulawesi, Indonesia). With a predominantly strike-slip mechanism, the question remains whether this unexpected tsunami was generated by the earthquake itself, or rather by earthquake-induced landslides. In this study we examine the tsunami potential of the co-seismic deformation. To this end, we present a novel geodetic data set of Global Positioning System and multiple Synthetic Aperture Radar-derived displacement fields to estimate a 3D co-seismic surface deformation field. The data reveal a number of fault bends, conforming to our interpretation of the tectonic setting as a transtensional basin. Using a Bayesian framework, we provide robust finite fault solutions of the co-seismic slip distribution, incorporating several scenarios of tectonically feasible fault orientations below the bay. These finite fault scenarios involve large co-seismic uplift (>2 m) below the bay due to thrusting on a restraining fault bend that connects the offshore continuation of two parallel onshore fault segments. With the co-seismic displacement estimates as input we simulate a number of tsunami cases. For most locations for which video-derived tsunami waveforms are available our models provide a qualitative fit to leading wave arrival times and polarity. The modeled tsunamis explain most of the observed runup. We conclude that co-seismic deformation was the main driver behind the tsunami that followed the Palu earthquake. Our unique geodetic data set constrains vertical motions of the sea floor, and sheds new light on the tsunamigenesis of strike-slip faults in transtensional basins

Unstructured Orthogonal Meshes for Modeling Coastal and Ocean Flows

In this thesis a z?layer unstructured C-grid finite volume hydrostatic model is presented. An efficient and highly scalable implicit technique for the solution of the free surface equation is combined with an Eulerian approach for the advection of momentum. A consistent velocity reconstruc- tion procedure which not only satisfies the continuity law but also guarantees the discrete kinetic energy conservation is presented. It is shown that an ac- curate velocity reconstruction procedure is of crucial importance not only for discretization of the Coriolis term, but also for the correct advection of mo- mentum, especially in the multilayer case. Unlike other z?layer models the method presented here ensures that the staircase representation of bathymetry and free surface has no influence on the vertical structure of the flow. The method is therefore guaranteed to be strictly momentum conservative, also in the layers containing the free surface and bed. A number of test cases are presented to show that the model is able to accu- rately simulate Coriolis dominated flows and flooding and drying processes both in the depth-averaged case and in the presence of multiple z?layers. A simulation of the 2004 Indian Ocean tsunami is used to evaluate the ability of the method to simulate fast propagating tsunami waves and detailed inundation processes. Results obtained using two different rupture models are compared to the tide gauge arrival times, satellite altimetry data and the inundation ob- servations in the Banda Aceh area. The comparison is used not only to assess the quality of the underlying rupture models but also to determine the value of the available data sources for such an assessment. Preliminary results of the unstructured grid fine resolution tidal model the southern North Sea including the Rhine-Scheldt Delta region are presented. The model is able to correctly reproduce the essential characteristics of the M2 tide, as well as of the most important nonlinear shallow water overtides M4 or M6. The simulated velocity field was used to evaluate the Simpson- Hunter stratification parameter, the variability of frontal positions due to tidal advection and spring-neap adjustment.Hydraulic EngineeringCivil Engineering and Geoscience

Definition of the Parameters of Surface Layer Based on Functionality of Parts

The problem of increased reliability of parts is solved in the direction of obtaining the characteristics of their surface layer, providing the highest possible wear resistance. Tolerances on the accuracy of the machine, set on the basis of its functionality, are divided into tolerances for the manufacture of the machine and wear tolerances. In order to increase the reliability of products, they strive for the greatest possible tolerance for wear, increasing the accuracy of parts manufacturing. As a result, the costs of manufacturing the machine unnecessarily increase. The dependence of the rate of wear of parts on the roughness and hardness of their surfaces is extreme; therefore, the task of determining the parameters of the surface layer of the parts is optimization. The use of the wear rate of rubbing surfaces is justified as an optimization criterion. The technique and algorithm for assigning the parameters of the surface layer, providing a minimum rate of wear of the mating surfaces are presented. To solve this problem, a random search method was used. A method for calculating the tolerances for the manufacture and wear of mated parts operating under friction conditions is proposed

High resolution tidal model of Canadian Arctic Archipelago, Baffin and Hudson Bay

Ice induced variability of tides in the Canadian Arctic Archipelago, including Baffin Bay and Hudson Strait/Hudson Bay system, was studied by means of a new high resolution tidal model. Here we show that the seasonal variations of the tidal constants are significant in the major part of the domain. Month to month changes of the tidal phases can reach 180 degrees due to changes in the number and positions of the amphidromic points, whereas the amplitude variations are especially large in the near resonant basins. We also show that the tidal seasonality has undergone dramatic changes in the past decades due the decaying extent of the Arctic sea ice. These seasonal/decadal scale changes not only vary tidal dissipation on the shelf, but also impact tides in the adjacent open ocean and, therefore, cannot be neglected.Environmental Fluid Mechanic