37 research outputs found
Elastic Wavefield Modeling for Arbitrarily Oriented Orthotropic Media
Composite materials have gained a considerable importance, being widely applied e.g. in aerospace industries as unidirectional, layered or woven structures. Through their complex build-up these materials exhibit anisotropic elastic behavior, raising considerable difficulties for ultrasonic nondestructive testing techniques. In modeling the interaction of elastic waves with such media a simple tool of assisting analysis is available. In this respect, simulation and optimization allow for a reduction of experimental work and an increase in reliability of applied testing procedures. For materials exhibiting orthotropic elastic symmetry, fundamental plane wave characteristics are presented in this contribution. These relationships are further applied for transducer-field modeling using the Generalized Point Source Synthesis method [1]. Since for complex-shaped components the materialâs natural symmetry planes are in general not identical with the componentâs surfaces, a respective transformation has been applied recently to yield a compact elastic tensor representation for such configurations [2]. Based on this formulation, all analytical results are obtained in a coordinate-free form, where the materialâs spatial orientation appears as an additional parameter. Since orthotropy includes the higher symmetries tetragonal, transversely isotropic, cubic and isotropic, the results presented cover most of the materials of todayâs industrial interest. Numerical results cover slowness and group velocity diagrams as well as field pattern calculations for commercial transducers including time-depedent rf-impulse modeling
Elastic Wave Diffraction at Cracks in Anisotropic Materials
Ultrasonic inspection is used to confirm that there are no defects of concern in various regions of a nuclear reactor primary circuit. All materials are naturally anisotropic, but if the grains are small relative to the ultrasonic wavelength and are also randomly oriented, then the material will appear as homogeneous and isotropic as in ferritic steel. The ultrasonic wavelength is chosen as a compromise between resolution of defect size and acoustic noise from grain boundaries. In austenitic steel, the wavelength chosen will typically be smaller than the grain size, at least in one direction. The grains are not randomly oriented but exhibit macroscopic patterns which depend on the welding process, and the material is neither homogeneous nor isotropic
Crystal dynamics of forming Îľ-martensite with {334}Îą habitus planes in titanium
Formation of crystals with {334}ι habitus planes often observed in titanium during the BCC-HCP (ι-ξ) reorganization is considered in the context of the dynamic theory of martensitic transformations. It is demonstrated that the fast wave growth of the crystals is started in elastic fields of edge dislocations with lines <11combining overline 0>ι and Burgers vectors <001>ι. Š 2013 Springer Science+Business Media New York
A theoretical entropy score as a single value to express inhibitor selectivity
<p>Abstract</p> <p>Background</p> <p>Designing maximally selective ligands that act on individual targets is the dominant paradigm in drug discovery. Poor selectivity can underlie toxicity and side effects in the clinic, and for this reason compound selectivity is increasingly monitored from very early on in the drug discovery process. To make sense of large amounts of profiling data, and to determine when a compound is sufficiently selective, there is a need for a proper quantitative measure of selectivity.</p> <p>Results</p> <p>Here we propose a new theoretical entropy score that can be calculated from a set of IC<sub>50 </sub>data. In contrast to previous measures such as the 'selectivity score', Gini score, or partition index, the entropy score is non-arbitary, fully exploits IC<sub>50 </sub>data, and is not dependent on a reference enzyme. In addition, the entropy score gives the most robust values with data from different sources, because it is less sensitive to errors. We apply the new score to kinase and nuclear receptor profiling data, and to high-throughput screening data. In addition, through analyzing profiles of clinical compounds, we show quantitatively that a more selective kinase inhibitor is not necessarily more drug-like.</p> <p>Conclusions</p> <p>For quantifying selectivity from panel profiling, a theoretical entropy score is the best method. It is valuable for studying the molecular mechanisms of selectivity, and to steer compound progression in drug discovery programs.</p
Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays
This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPThe CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12 000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);
Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR
(Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
25th Annual Computational Neuroscience Meeting: CNS-2016
Abstracts of the 25th Annual Computational Neuroscience
Meeting: CNS-2016
Seogwipo City, Jeju-do, South Korea. 2â7 July 201
The Annotations of Some Words of Tea Culture in the Song Poetry
People of the Song period, either the upper class or the lower class, were fond of drinking tea; hence a unique kind of tea culture and a category of words related to tea culture in the poetry of that era. The literal meanings of this category of words are different from and betray their actual meanings and pose great difficulties for reading the Song poetry.This article on the annotations of some words of tea culture in the Song poetry is a topic to be studied in a large research project on the Quan Song Shi