Three-dimensional dynamic rupture simulation with a high-order discontinuous Galerkin method on unstructured tetrahedral meshes

Accurate and efficient numerical methods to simulate dynamic earthquake rupture and wave propagation in complex media and complex fault geometries are needed to address fundamental questions in earthquake dynamics, to integrate seismic and geodetic data into emerging approaches for dynamic source inversion, and to generate realistic physics-based earthquake scenarios for hazard assessment. Modeling of spontaneous earthquake rupture and seismic wave propagation by a high-order discontinuous Galerkin (DG) method combined with an arbitrarily high-order derivatives (ADER) time integration method was introduced in two dimensions by de la Puente et al. (2009). The ADER-DG method enables high accuracy in space and time and discretization by unstructured meshes. Here we extend this method to three-dimensional dynamic rupture problems. The high geometrical flexibility provided by the usage of tetrahedral elements and the lack of spurious mesh reflections in the ADER-DG method allows the refinement of the mesh close to the fault to model the rupture dynamics adequately while concentrating computational resources only where needed. Moreover, ADER-DG does not generate spurious high-frequency perturbations on the fault and hence does not require artificial Kelvin-Voigt damping. We verify our three-dimensional implementation by comparing results of the SCEC TPV3 test problem with two well-established numerical methods, finite differences, and spectral boundary integral. Furthermore, a convergence study is presented to demonstrate the systematic consistency of the method. To illustrate the capabilities of the high-order accurate ADER-DG scheme on unstructured meshes, we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes curved faults, fault branches, and surface topography

Lime requirement of pond soils for aquaculture around Cochin backwaters

The use of lime in pond fish culture has been advocated by fish culturists over a large part of the world. Liming increases the pH of bottom mud and thereby increases the availability of phosphorous added as fertilizer. The application of lime to improve the fertility as well as production is already being practiced by traditional farmers and aquaculturists in the culture systems bordering the Cochin Backwaters and the Vembanad Lake. In the present investigation soil samples were collected from different seasonal and perennial prawn culture fields during the premonsoon and monsoon seasons. The samples were estimated for their lime requirement during both the seasons

Market Structure, Organizational Structure, and R&D Diversity

We examine the effects of market structure and the internal organization of firms on equilibrium R&D projects. We compare a monopolist's choice of R&D portfolio to that of a welfare maximizer. We next show that Sah and Stiglitz's finding that the market portfolio of R&D is independent of the number of firms under Bertrand competition extends to neither Cournot oligopoly nor a cartel. We also show that the ability of firms to pre-empt R&D by rivals along particular research paths can lead to socially excessive R&D diversification. Lastly, using Sah and Stiglitz's definition of hierarchy, we establish conditions under which larger hierarchies invest in smaller portfolios.

Perspective on Metallic Antiferromagnets

Antiferromagnet materials have recently gained renewed interest due to their possible use in spintronics technologies, where spin transport is the foundation of their functionalities. In that respect metallic antiferromagnets are of particular interest, since they enable complex interplays between electronic charge transport, spin, optical, and magnetization dynamics. Here we review phenomena where the metallic conductivity provides unique perspectives for the practical use and fundamental properties of antiferromagnetic materials.Comment: 18 pages, 10 figure

An automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat 8 imagery: A new rock outcrop map and area estimation for the entire Antarctic continent

As the accuracy and sensitivity of remote-sensing satellites improve, there is an increasing demand for more accurate and updated base datasets for surveying and monitoring. However, differentiating rock outcrop from snow and ice is a particular problem in Antarctica, where extensive cloud cover and widespread shaded regions lead to classification errors. The existing rock outcrop dataset has significant georeferencing issues as well as overestimation and generalisation of rock exposure areas. The most commonly used method for automated rock and snow differentiation, the normalised difference snow index (NDSI), has difficulty differentiating rock and snow in Antarctica due to misclassification of shaded pixels and is not able to differentiate illuminated rock from clouds. This study presents a new method for identifying rock exposures using Landsat 8 data. This is the first automated methodology for snow and rock differentiation that excludes areas of snow (both illuminated and shaded), clouds and liquid water whilst identifying both sunlit and shaded rock, achieving higher and more consistent accuracies than alternative data and methods such as the NDSI. The new methodology has been applied to the whole Antarctic continent (north of 82°40′ S) using Landsat 8 data to produce a new rock outcrop dataset for Antarctica. The new data (merged with existing data where Landsat 8 tiles are unavailable; most extensively south of 82°40′ S) reveal that exposed rock forms 0.18 % (21 745 km2) of the total land area of Antarctica: half of previous estimates

Mapping the e-Learning Assessment Domain: Concept Maps for Orientation and Navigation

Concept or Topic Maps have long been used as a method of categorizing and organizing information about a domain. Building them can help people conceptualize an area and spot trends or gaps, and as a presentation method they quickly provide an overview and general impression of a space. We are currently constructing a Reference Model of the Assessment Domain that takes the form of a highly interlinked dynamic website. This represents the assessment domain via the software, projects, standards and use cases of which it is composed. In this paper we present our efforts to create complimentary concept maps of the assessment domain, not as an overview, but for navigation and orientation within the domain. These concept maps, which model resources and activities independently, have been corroborated with practitioners in the e-learning community

[beta]-(2-Hydroxyphenyl)ethanolamine hydrochloride [2-amino-1-(2-hydroxyphenyl)ethanol hydrochloride]

CsH~2NO2+.C1 -, m.p. 441-449 K (from ethyl acetate), P212~2 l, a = 7.363 (2), b = 21.824 (6), c = 5.790 (2)/~, Z = 4, D x = 1.354, D m = 1.356 Mg m -3 (flotation: CC14-C6H6). The structure was solved by MULTAN. Full-matrix least-squares refinement converged to R = 0.057 for the R configuration and to R = 0.056 for the S configuration (P \u3c 0.05). This is consistent with spontaneous resolution of the title compound, single crystals of which provided optically active aqueous solutions. A partially occupied oxygen site O(1)\u27 is attributed to the oxidation of the alkyl hydroxyl group to a ketone during the data collection. The CI- is hydrogen bonded to H2(N)554, H3(N)555, and 1-t(O2)655 (2.37, 2-19, and 2.10 A). Both O(1) and 0(2) are internally hydrogen bonded [HI(N)...O(1), 2.41 and H(O1)...O(2) = 2.24 A]. Intramolecular hydrogen bonding may account for the unusual pharmacological properties of this compound in which only the N-C(1)-C(2)-O(1) and the O(1)-C(2)- C(3)-C(4) and O(1)-C(2)-C(3)-C(8) torsion angles (-41, -60, +122 ° ) differ significantly from those of other phenylethanolamines

Commercial users panel

The discussions of motives and requirements for telerobotics application demonstrated that, in many cases, lack of progress was a result not of limited opportunities but of inadequate mechanisms and resources for promoting opportunities. Support for this conclusion came from Telerobotics, Inc., one of the few companies devoted primarily to telerobot systems. They have produced units for such diverse applications as nuclear fusion research, particle accelerators, cryogenics, firefighting, marine biology/undersea systems and nuclear mobile robotics. Mr. Flatau offered evidence that telerobotics research is only rarely supported by the private sector and that it often presents a difficult market. Questions on the mechanisms contained within the NASA technology transfer process for promoting commercial opportunities were fielded by Ray Gilbert and Tom Walters. A few points deserve emphasis: (1) NASA/industry technology transfer occurs in both directions and NASA recognizes the opportunity to learn a great deal from industry in the fields of automation and robotics; (2) promotion of technology transfer projects takes a demand side approach, with requests to industry for specific problem identification. NASA then proposes possible solutions; and (3) comittment ofmotivated and technically qualified people on each end of a technology transfer is essential

The 2016 Academic Emergency Medicine Consensus Conference, Shared Decision Making in the Emergency Department: Development of a Policy-relevant Patient-centered Research Agenda Diagnostic Testing Breakout Session Report.

Diagnostic testing is an integral component of patient evaluation in the emergency department (ED). Emergency clinicians frequently use diagnostic testing to more confidently exclude worst-case diagnoses rather than to determine the most likely etiology for a presenting complaint. Increased utilization of diagnostic testing has not been associated with reductions in disease-related mortality but has led to increased overall healthcare costs and other unintended consequences (e.g., incidental findings requiring further workup, unnecessary exposure to ionizing radiation or potentially nephrotoxic contrast). Shared decision making (SDM) presents an opportunity for clinicians to discuss the benefits and harms associated with diagnostic testing with patients to more closely tailor testing to patient risk. This article introduces the challenges and opportunities associated with incorporating SDM into emergency care by summarizing the conclusions of the diagnostic testing group at the 2016 Academic Emergency Medicine Consensus Conference on SDM. Three primary domains emerged: 1) characteristics of a condition or test appropriate for SDM, 2) critical elements of and potential barriers to SDM discussions on diagnostic testing, and 3) financial aspects of SDM applied to diagnostic testing. The most critical research questions to improve engagement of patients in their acute care diagnostic decisions were determined by consensus