Search results for " resolution"
showing 10 items of 1159 documents
New computational techniques for finite-difference Weighted Essentially Non-Oscillatory schemes and related problems
2014
High-Resolution Shock-Capturing (HRSC) schemes constitute the state of the art for computing accurate numerical approximations to the solution of many hyperbolic systems of conservation laws, especially in computational fluid dynamics. A drawback of these schemes is that most of them use the spectral decomposition of the Jacobian matrix of the system to compute the numerical approximations by local projections to characteristic fields. The numerical solutions obtained are often excellent in terms of resolution, but the computational effort needed may be too high for some problems, especially those for which the spectral information of the flux Jacobian matrix is not available or is quite di…
The BRICS Centres of Dispute Resolution: causes, state of the art, and prospects
2023
The idea of an enhanced cooperation and exchange of knowledge and best practices among its member states in the fields of trade, commerce, and investments -among others- is at the heart of BRICS. In fact, intra-BRICS trade has nearly tripled over the last decade, supported by an increase in intra-regional trade for all member countries. Thanks to their influential and remarkable progress in promoting local currency (for de-dollarisation purposes), regional FDI, and regional trade, the BRICS economies have emerged and have taken a new space in the twenty-first century. This reinforced one of the core objectives pursued by BRICS which is that of enhancing the five developing economies’ role i…
Acceso a la Justicia de los Consumidores a través del ADR y del ODR
2018
El avance de las tecnologías de información y la comunicación nos ha llevado a cambiar nuestra forma de relacionarnos tanto entre nosotros, como con las administraciones. Además, la adquisición de bienes de consumo a través del medio online es cada día más importante para en la economía global y doméstica. Todo ello, llevó a la Unión Europea a la creación del llamado Mercado Único Digital, donde se estableció como uno de los objetivos prioritarios mejorar la tutela efectiva de los ciudadanos comunitarios que realizan compras a través de internet. El presente trabajo tiene por objeto realizar un análisis sobre las facilidades y dificultades que encuentran los consumidores a la hora de accede…
Pulsating in Unison at Optical and X-Ray Energies: Simultaneous High Time Resolution Observations of the Transitional Millisecond Pulsar PSR J1023+00…
2019
PSR J1023+0038 is the first millisecond pulsar discovered to pulsate in the visible band; such a detection took place when the pulsar was surrounded by an accretion disk and also showed X-ray pulsations. We report on the first high time resolution observational campaign of this transitional pulsar in the disk state, using simultaneous observations in the optical (TNG, NOT, TJO), X-ray (XMM-Newton, NuSTAR, NICER), infrared (GTC) and UV (Swift) bands. Optical and X-ray pulsations were detected simultaneously in the X-ray high intensity mode in which the source spends $\sim$ 70% of the time, and both disappeared in the low mode, indicating a common underlying physical mechanism. In addition, o…
Short and Efficient Chemoenzymatic Synthesis of Goniothalamin.
2004
A high-yielding three-step synthesis of goniothalamin involving an enzymatic kinetic resolution in the presence of vinyl acrylate followed by ring-closing metathesis is discussed.
253. An accurate and operator independent method for biological tumour volume segmentation
2018
Purpose The aim of this paper is to develop an operator independent method for biological tumour volume (BTV) delineation from Positron Emission Tomography (PET) images. BTV delineation is challenging because of the low spatial resolution and high noise level in PET images. In addition, BTV varies substantially depending on the method used to segment. Manual delineation is widely-used, but it is strongly user dependent. Methods The proposed method starts with the automatic identification of the PET slice with maximum Standardized Uptake Value (SUV). Then, a user- independent mask is obtained by a rough pre-segmentation step and it is used to perform the local active contour segmentation on …
VLBI detection of the HST-1 feature in the M87 jet at 2 cm
2010
A bright feature 80 pc away from the core in the powerful jet of M87 shows highly unusual properties. Earlier radio, optical and X-ray observations have shown that this feature, labeled HST-1, is superluminal, and is possibly connected with the TeV flare detected by HESS in 2005. It has been claimed that this feature might have a blazar nature, due to these properties. To examine the possible blazar-like nature of HST-1, we analyzed lambda 2 cm VLBA archival data from dedicated full-track observations and the 2 cm survey/MOJAVE VLBI monitoring programs obtained between 2000 and 2009. Applying VLBI wide-field imaging techniques, the HST-1 region was imaged at milliarcsecond resolution. Here …
ChemInform Abstract: High-Resolution Solid-State NMR Spectroscopy of Steroids and Their Derivatives
2013
Abstract: Steroids are an important class of organic compounds containing a vast array of biologically and physiologically essential molecules. Due to their availability, relatively straightforward derivatizability, and endogeneity, they are widely used in pharmacological applications. The investigation of molecular and physicochemical properties of active pharmaceutical ingredients (APIs) in the solid state is important, because these properties are directly related to their pharmacological activity. Several methods are available for this purpose. Solid-state NMR spectroscopy offers a nondestructive and flexible technique, providing both structural and dynamic information. It can be applie…
High-Resolution Solid-State NMR Spectroscopy of Steroids and Their Derivatives
2013
Abstract: Steroids are an important class of organic compounds containing a vast array of biologically and physiologically essential molecules. Due to their availability, relatively straightforward derivatizability, and endogeneity, they are widely used in pharmacological applications. The investigation of molecular and physicochemical properties of active pharmaceutical ingredients (APIs) in the solid state is important, because these properties are directly related to their pharmacological activity. Several methods are available for this purpose. Solid-state NMR spectroscopy offers a nondestructive and flexible technique, providing both structural and dynamic information. It can be applie…
The sustainable synthesis of levetiracetam by an enzymatic dynamic kinetic resolution and an ex-cell anodic oxidation
2021
Levetiracetam is an active pharmaceutical ingredient widely used to treat epilepsy. We describe a new synthesis of levetiracetam by a dynamic kinetic resolution and a ruthenium-catalysed ex-cell anodic oxidation. For the enzymatic resolution, we tailored a high throughput screening method to identify Comamonas testosteroni nitrile hydratase variants with high (S)-selectivity and activity. Racemic nitrile was applied in a fed-batch reaction and was hydrated to (S)-(pyrrolidine-1-yl)butaneamide. For the subsequent oxidation to levetiracetam, we developed a ligand-free ruthenium-catalysed method at a low catalyst loading. The oxidant was electrochemically generated in 86% yield. This route pro…