Earth system models (ESMs) are state-of-the-art climate models that allow numerical simulations of the past, present-day, and future climate. To extend our understanding of the Earth system and ...improve climate change projections, the complexity of ESMs heavily increased over the last decades. As a consequence, the amount and volume of data provided by ESMs has increased considerably. Innovative tools for a comprehensive model evaluation and analysis are required to assess the performance of these increasingly complex ESMs against observations or reanalyses. One of these tools is the Earth System Model Evaluation Tool (ESMValTool), a community diagnostic and performance metrics tool for the evaluation of ESMs. Input data for ESMValTool needs to be formatted according to the CMOR (Climate Model Output Rewriter) standard, a process that is usually referred to as "CMORization". While this is a quasi-standard for large model intercomparison projects like the Coupled Model Intercomparison Project (CMIP), this complicates the application of ESMValTool to non-CMOR-compliant climate model output.
This paper complements a series of now four publications that document the release of the Earth System Model Evaluation Tool (ESMValTool) v2.0. It describes new diagnostics on the hydrological cycle, ...extreme events, impact assessment, regional evaluations, and ensemble member selection. The diagnostics are developed by a large community of scientists aiming to facilitate the evaluation and comparison of Earth system models (ESMs) which are participating in the Coupled Model Intercomparison Project (CMIP). The second release of this tool aims to support the evaluation of ESMs participating in CMIP Phase 6 (CMIP6). Furthermore, datasets from other models and observations can be analysed. The diagnostics for the hydrological cycle include several precipitation and drought indices, as well as hydroclimatic intensity and indices from the Expert Team on Climate Change Detection and Indices (ETCCDI). The latter are also used for identification of extreme events, for impact assessment, and to project and characterize the risks and impacts of climate change for natural and socio-economic systems. Further impact assessment diagnostics are included to compute daily temperature ranges and capacity factors for wind and solar energy generation. Regional scales can be analysed with new diagnostics implemented for selected regions and stochastic downscaling. ESMValTool v2.0 also includes diagnostics to analyse large multi-model ensembles including grouping and selecting ensemble members by user-specified criteria. Here, we present examples for their capabilities based on the well-established CMIP Phase 5 (CMIP5) dataset.
Synthetic hydroxyapatite (HAp) is one of the most commonly used material for a large variety of biomedical applications. This paper presents structural, morphological and preliminary ultrasonic ...characterizations of the HAp nanopowder synthesized by an adapted co-precipitation method. To this end, the structural and morphological properties were evaluated by Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). Biological investigation were also performed in order to evidence the influence of HAp tablets on the development and growth of endothelial cells. The ultrasonic measurements obtained for the HAp dispersion allowed us to calculate the ultrasonic velocity and the attenuation. The study of ultrasonic waves propagation through dispersions could be used as future standard quality test, thus improving the quality of biomedical devices based on hydroxyapatite.
The ultrasonic nondestructive evaluation of structural integrity of pipes in high risk industries such as chemical or nuclear, represents a domain of highest importance. The inspection of kilometers ...of piping in rough conditions is a difficult if not an impossible task. Guided ultrasonic waves can propagate however along tens of meters in pipes and bring by the reflected signal, important information concerning the presence of flaws. There are three classes of guided modes in a pipe: longitudinal, torsional and flexural. The longitudinal modes have an axial symmetry of the radial and axial displacements. These waves prove to be most sensitive to partly circumferential flaws. These waves are dispersive, the wave velocity strongly depending on the frequency. The torsional modes are less dispersive, especially the fundamental SH0 mode. Moreover, the radial displacements are negligible, reducing the interaction with the surrounding fluids and thus reducing the attenuation. The interaction of these waves with axial flaws is more pronounced. The flexural modes are highly dispersive and attenuated. However, if the symmetry of the emitting transducer is not perfect, these modes can propagate in the pipe and their properties must be understood. The presence of fluid inside and in some cases outside the inspected pipe represents a challenging problem of computing the guided modes dispersion curves. The various guided modes velocities and attenuations are determined for several fluids which might be filling and surrounding the common size steel pipes. A dedicated software package developed by our team is used for this purpose. These dispersion curves are used for optimal numerical simulation, using the Finite Elements Method (FEM), in order to verify the attenuation mechanism. The obtained results allow a motivated selection of the least attenuated mode, from the three classes explained before, at a given inspection frequency and for a typical steel pipe, filled with various fluids. The numerical data can be used for comparison with laboratory experiments. The experimental setup is using common ultrasonic transducers in a special geometrical arrangement. The experiments allow the measurement of the numerically predicted modal attenuation. The maximum expected inspection range can be thus determined before the inspection on real industrial piping.
Given a mathematical model quantifying the viral infection of pandemic influenza H1N1pdm09-H275 wild type (WT) and H1N1pdm09-H275Y mutant (MUT) strains, we describe a simple method of estimating the ...model's constant parameters using Monte Carlo methods. Monte Carlo parameter estimation methods present certain advantages over the bootstrapping methods previously used in such studies: the result comprises actual parameter distributions (posteriors) that can be used to compare different viral strains; the recovered parameter distributions offer an exact method to compute credible intervals (similar to the frequentist 95% parametric confidence intervals (CI)), that, in turn, using a suitable analysis statistic, will be narrower than the ones obtained from bootstrapping; given an appropriate computational parallelization, Monte Carlo methods are also faster and less computationally intensive than bootstrapping. We fit Gaussian distributions to the parameter posterior distributions and use a two-sided Kolmogorov-Smirnoff test to compare the two strains from a parametric point of view; our example result shows that the two strains are 94% different. Furthermore, based on the obtained parameter values, we estimate the reproductive number R0 for each strain and show that the infectivity of the mutant strain is larger than the wild type strain.
Development of corrosion or/and fatigue crack propagation are the most common causes of structural degradation in road and railway tank vessels. An acoustic emission based monitoring procedure in ...conjunction with follow-up nondestructive testing is here proposed as a promising alternative to the conventional inspection processes enabling continuous health monitoring of the tank structures. Thereby, finite element analysis taking the respective ADR and RID tank design loads into account is proposed as a capable tool to be applied in early stages of development to reveal the hot spot areas, where acoustic emission sensors have to be positioned. The developed health monitoring procedure is successfully validated on tank structures providing degradation in terms of natural and artificial corrosion and fatigue cracks. The results pinpoint the capability of acoustic emission testing to reliably detect and identify each individual degradation mechanism in early stages under operational loading conditions.
In this paper, the edge mode vibration is studied with three different methods: the reciprocal work method, already used by Torvik J. Acoust. Soc. Am. 41 (1967) 346 to model this phenomenon, the
...S-parameter method and a finite element model that are applied for the first time to the study of the edge resonance. Moreover, laser probe measurements of the edge mode have also been performed and compared to the numerical predictions. The good agreement between the numerical predictions and the experimental data allows full understanding of the resonant phenomenon. The edge resonance is linked to the strong increase in amplitude of two complex Lamb waves, and the edge mode is proved to radiate into the plate as the first symmetrical Lamb mode
S
0. Displacements at the edge and away from the edge have been computed and measured to evaluate the spatial and temporal behaviour of the edge mode. The dependence of the edge resonance frequency and amplitude on the Poisson coefficient has also been studied.
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