876 research outputs found
Geometrical 3D laser scanner model of a Chalcolithic vessel (Gor, Granada, Spain)
The most recent computer technologies of 3D geometrical modelling provide a great quantity of tools for archaeological investigation. This paper presents an application of the 3D laser scanner to study the metric and morphometric parameters of a Chalcolithic pottery vessel based on a 3D meshed triangular model. This model is referenced geometrically by high-precision fitting to the real object, enabling the study of some of the most important archaeological characteristics with great accuracy (texture, damage, profiles, etc.) as well as a reconstruction of those damaged parts. The computerized model has been used to study the metric and geometric parameters of the vessel, applying different statistical tests to analyse the width of vessel and the variability of some constructive parameters. These analyses allow us to compute any measurement, such as the surface area of vessel, the center of masses, the volume, and the regularly spaced contour levels of the interior and exterior. The results indicate the skill of the potters of the Copper Age and their knowledge of some elementary mathematical concepts of geometry and metric
Effect of the Reduction Temperature of PdAg Nanoparticles during the Polyol Process in the Ethanol Electrooxidation Reaction
This work reports the effect of reduction temperature during the synthesis of PdAg catalysts through the polyol process and their evaluation in the ethanol electrooxidation reaction (EOR). The characterization was performed using Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). The electrochemical evaluation for the ethanol electrooxidation reaction was implemented in alkaline medium using chronoamperometry (CA) and cyclic voltammetry (CV). An important effect of the reduction temperature on electroactivity and catalytic stability was observed: both the maximum current density and the catalytic stability were higher in the catalyst synthesized at the highest temperature (135°C). This performance was associated with the extent of the interaction between Pd and Ag which was measured in terms of the structural expansion of Pd
Evaluation of multiple protein docking structures using correctly predicted pairwise subunits
<p>Abstract</p> <p>Background</p> <p>Many functionally important proteins in a cell form complexes with multiple chains. Therefore, computational prediction of multiple protein complexes is an important task in bioinformatics. In the development of multiple protein docking methods, it is important to establish a metric for evaluating prediction results in a reasonable and practical fashion. However, since there are only few works done in developing methods for multiple protein docking, there is no study that investigates how accurate structural models of multiple protein complexes should be to allow scientists to gain biological insights.</p> <p>Methods</p> <p>We generated a series of predicted models (decoys) of various accuracies by our multiple protein docking pipeline, Multi-LZerD, for three multi-chain complexes with 3, 4, and 6 chains. We analyzed the decoys in terms of the number of correctly predicted pair conformations in the decoys.</p> <p>Results and conclusion</p> <p>We found that pairs of chains with the correct mutual orientation exist even in the decoys with a large overall root mean square deviation (RMSD) to the native. Therefore, in addition to a global structure similarity measure, such as the global RMSD, the quality of models for multiple chain complexes can be better evaluated by using the local measurement, the number of chain pairs with correct mutual orientation. We termed the fraction of correctly predicted pairs (RMSD at the interface of less than 4.0Å) as <it>fpair </it>and propose to use it for evaluation of the accuracy of multiple protein docking.</p
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