193 research outputs found
Arcon
No full textContemporary end-to-end data pipelines need to combine many diverse workloads such as machine learning, relational operations, stream dataflows, tensor transformations, and graphs. For each of these workload types, there exists several frontends (e.g., SQL, Beam, Keras) based on different programming languages as well as different runtimes (e.g., Spark, Flink, Tensorflow) that optimize for a particular frontend and possibly a hardware architecture (e.g., GPUs). The resulting pipelines suffer in terms of complexity and performance due to excessive type conversions, materialization of intermediate results, and lack of cross-framework optimizations. Arcon aims to provide a unified approach to declare and execute tasks across frontend-boundaries as well as enabling their seamless integration with event-driven services at scale. In this demonstration, we present Arcon and through a series of use-case scenarios demonstrate that its execution model is powerful enough to cover existing as well as upcoming real-time computations for analytics and application-specific needs. © 2019 Copyright held by the owner/author(s).</p
High-field electron paramagnetic resonance study of the polymerization in Na2Rb1-xCsxC60
No full textWe report on the study of the magnetic properties of the low-temperature polymer phases in Na2Rb1-xCsxC60
at 110 GHz microwave frequency with x varying between 0 and 1. The magnetic and structural properties of the polymer
phase strongly depend on the Cs content and its electronic structure progressively becomes quasi-one-dimensional as x is
increased. While the electronic properties of the polymeric Na2RbC60 appear to be close to three-dimensional metal,
Na2Rb0.3Cs0.7C60 shows characteristics of quasi-one-dimensional metal where instability in the electronic structure was
found as detected by the sudden disappearance of the ESR intensity due to the opening of the gap at the Fermi surface.
The observation of an additional resonance line below 15 K, which could be attributed to antiferromagnetic resonance,
suggests that the low-temperature polymeric phase in Na2Rb0.3Cs0.7C60 has a well-defined magnetic ground state
Comparative Evaluation of Condylar Guidance Angles Measured Using Arcon and Non-Arcon Articulators and Panoramic Radiographs—A Systematic Review and Meta-Analysis
No full textThe condylar guidance value (CGV) measurement constitutes an important part of a holistic prosthodontic treatment plan, with horizontal CGVs (HCGVs) and lateral CGVs (LCGVs) being two of the most prominently recognized. This systematic review aimed at evaluating the efficacy of two different types of CGV measurement protocols—articulators (both arcon and non-arcon) and panoramic radiographs. Additionally, it attempts to determine which of the mentioned methods performs better across several parameters. Several important web databases were searched using search terms derived from medical subject headings (MeSH), using keywords linked to “Arcon articulator”, “Condylar guidance angle”, “non-arcon articulator”, “Panoramic x-ray” and “Radiographic examination”, which constituted the first step in the study selection strategy. After completion, the search strategy which initially turned up to 831 papers, eventually ended up with 13 studies. The review and subsequent meta-analysis revealed that panoramic radiographs had noticeably greater efficacy in terms of the CGVs as compared to the articulators in the majority of the studies. Within the articulators, the arcon types recorded slightly higher CGVs than the non-arcon variety owing to the precision of jaw movement simulation in the former. However, further studies are required to validate these findings and establish more precise guidelines for the use of CGV measurement protocols in prosthodontic practice
Low temperature magnetic instabilities in triply charged fulleride polymers
No full textThe electronic properties of the C-60(3-) polymer in Na2Rb0.3Cs0.7C60 were studied by X-band and high
field (109.056 GHz) ESR. They are characteristic of a strongly correlated quasi-one-dimensional metal down to 45 K. On
further cooling, a pseudogap of magnetic origin opens at the Fermi level below 45 K with three-dimensional magnetic
ordering occurring below T-N approximate to 15 K, as confirmed by the observation of an antiferromagnetic resonance
mode. The Na2Rb1-xCsxC60 family of polymers offers a unique way to chemically control the electronic properties, as
the opening of the gap in this system of predominantly itinerant electrons is an extremely sensitive function of the
interchain separation
Soil humic acids may favour the persistence of hexavalent chromium in soil
No full textThe interaction between hexavalent chromium Cr(VI), as K(2)CrO(4), and standard humic acids (HAs) in bulk solution was studied using three complementary analytical methods: UV-Visible spectroscopy, X-ray absorption spectroscopy and differential pulse stripping voltammetry. The observed UV-Vis and X-ray absorption spectra showed that, under our experimental conditions, HAs did not induce reduction of Cr(VI) to its trivalent chemical form. The interaction between Cr(VI) and HAs has rather led to the formation of Cr(VI)-HAs micelles via supramolecular chemical processes. The reported results could contribute towards explaining the relative persistence of ecotoxic hexavalent chromium in soils
The structural and electronic evolution of Li4C60 through the polymer-monomer transformation
No full text
Electron spin resonance study of the polymeric phase of Na2RbC60
No full textThe structural and electronic properties of the polymeric phase of Na2RbC60 which comprises of C-C bridged
C-60(3-) chains have been studied between 410 and 4 K with the electron spin resonance (ESR) technique. On cooling,
the polymeric phase starts growing below similar to 250 K. Its fraction reaches a maximum at similar to 190 K, where
around 55% of the monomeric cubic phase have transformed to the polymer. The temperature dependence of the ESR
susceptibility suggests that the Na2RbC60 polymer is conducting down to 3 K. The ESR results exclude the possibility of
the existence of a ground-state instability and the formation of either a spin-density-wave (SDW) or a charge-densitywave
(CDW) sta
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