531 research outputs found
Near coast tsunami waveguiding: simulations for various wave models
Shallow parts in a sloping bottom toward the coast can be expected to act as a waveguide, in partial analogy with optical waveguiding. We will present numerical simulations that convincingly show that large enhanced wave amplification happens for tsunami waves in certain geometries and bathymetries. Since this is even the case for shallow regions that have cross sections of the order of badly resolved numerical scales, this phenomenon may at least partly explain that tsunami heights and coastal effects as observed in reality show such high variability along the coastline. This report, following [1], supports a more concise publication that will be published soon [2]. In this report we will provide detailed results of extensive simulations using various wave models and different gridsizes. We will show results obtained with the commonly used Shallow Water Equations and with a more accurate dispersive wave model. For the latter simulations we use a recently derived Variational Boussinesq model. We will also show that relatively small gridsizes are needed to capture the transversal flow near the waveguide; on grids that are too coarse, the enhanced amplification will not be observable. This may provide a partial explanation that spatial variability due to relatively shallow bottom variations will not be present in most simulations
Semi-empirical derived descriptors for the modelling of properties of N-containing heterocycles
The development of a knowledge base for basic active structures: an example case of dopamine agonists
<p>Abstract</p> <p>Background</p> <p>Chemical compounds affecting a bioactivity can usually be classified into several groups, each of which shares a characteristic substructure. We call these substructures "basic active structures" or BASs. The extraction of BASs is challenging when the database of compounds contains a variety of skeletons. Data mining technology, associated with the work of chemists, has enabled the systematic elaboration of BASs.</p> <p>Results</p> <p>This paper presents a BAS knowledge base, BASiC, which currently covers 46 activities and is available on the Internet. We use the dopamine agonists D1, D2, and Dauto as examples and illustrate the process of BAS extraction. The resulting BASs were reasonably interpreted after proposing a few template structures.</p> <p>Conclusions</p> <p>The knowledge base is useful for drug design. Proposed BASs and their supporting structures in the knowledge base will facilitate the development of new template structures for other activities, and will be useful in the design of new lead compounds via reasonable interpretations of active structures.</p
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