Search results for "Series"

NonclassicalPschorr andSandmeyer Reactions in Pyrazole Series

2005

The diazonium salt derived from 4-amino-N,1,3-trimethyl-N-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1H-pyrazole-5-carboxamide (14) was reacted with a mixture of CuSO4 and NaCl, with ascorbic acid as an initiator to afford the planar derivative 4,6-dihydro-1,4,6,8-tetramethyl-3-phenyldipyrazolo[3,4-b:4′,3′-d]pyridin-5(3H)-one (16) and its unexpected isomer 4,6-dihydro-3,4,6,8-tetramethyl-1-phenyldipyrazolo[4,3-b:4′,3′-d]pyridin-5(1H)-one (17), as well as the epimers (3S,4S)- (or (3S,4R)-) and (3S,4R)- (or (3S,4S)-) 4-chloro-2,4-dihydro-1′,3′,5,5′-tetramethyl-2-phenylspiro[pyrazole-3,4′(1′H)-pyrrolo[3,4-c]pyrazol]-6′(5′H)-one (18a and b, respectively). Epimers 18a and b were converted under basic c…

1982

p-Cresol and eight oligo[(hydroxyphenylene)methylene] compounds 1b–e and 4a–d could be esterified with good yields with acryloyl chloride or propionyl chloride, respectively, in the presence of triethylamine. The simple and multiple acrylates and propionates were characterized by determination of their molar masses, elemental analyses, hydrogenation of the CC double bonds in the acrylate groups, and by their IR- and UV-spectra. No steric hindrance could be ascertained. Acrylates with more than three phenolic units in their molecules were found to have a range of melting, whereas all the propionates possess sharp melting points. This can be explained by polymerization of the acrylates which …

Cycloadditions in the pyrrole series

1972

DNA-binding studies of a series of novel water-soluble derivatives of 1,4-dihydropyridine

2018

Aim. to determine DNA interaction modes for a series of 1,4-dihydropyridines with different biological activities synthesized in the Latvian Institute of Or-ganic Synthesis. Methods. Affinity of the compounds to DNA was detected by UV/VIS spec-trometry and re-proofed by means of spectrofluorimetry, EBr extrusion assay, cyclic voltammetry and DNA melting. Radical scavenging was tested by electron paramagnetic resonance spectros-copy, peroxynitrite binding was monitored spectrophotometrically, protection of DNA against hydroxyl radical was determined by gel electrophoresis. Results. In a series of water-soluble monocyclic derivatives of 1,4-dihydropyridine with carboxylate groups in position-…

Book Review: Resorcinol. Its Uses and Derivatives.(Series: Topics in Applied Chemistry.) By H. Dressler

1996

Sitcom, crisis y sociedad norteamericana: análisis de la ficción televisiva estadounidense desde los años 80 hasta la actualidad

2017

El propósito que persigue la tesis doctoral es profundizar en la esencia de la sitcom norteamericana, en cómo ha evolucionado a lo largo de los años, de qué manera el contexto histórico de una época ha afectado al formato y viceversa, cuáles son los intereses o intenciones que esconde tras sus tramas y ver el modo en el que han sido renovadas ciertas cuestiones como son los personajes y sus conflictos, la idea de familia, el papel de la mujer, los roles sexuales, la puesta en escena o el humor. Con el fin de alcanzar tal propuesta, se han utilizado tres series de televisión contemporáneas como eje central para analizar todos los aspectos relevantes, entre los que se hallan incluidos los ant…

Information Transfer in Linear Multivariate Processes Assessed through Penalized Regression Techniques: Validation and Application to Physiological N…

2020

The framework of information dynamics allows the dissection of the information processed in a network of multiple interacting dynamical systems into meaningful elements of computation that quantify the information generated in a target system, stored in it, transferred to it from one or more source systems, and modified in a synergistic or redundant way. The concepts of information transfer and modification have been recently formulated in the context of linear parametric modeling of vector stochastic processes, linking them to the notion of Granger causality and providing efficient tools for their computation based on the state&ndash

An effective approach for the maintenance scheduling in large systems with required reliability level: A case study

2015

This paper deals with the problem of the maintenance scheduling in a multi-component system for which a required reliability level has to be warranted until the next planned stop for maintenance. Particularly, the tackled problem concerns both the determination of the elements set on which to perform preventive maintenance and the optimal number of maintenance crews in order to warranty the required reliability level at the minimum maintenance cost. The problem is formulated as a mathematical programming model that becomes very hard to solve for large practical systems. For such reason, a new effective approach based on a constrained genetic algorithm is herein proposed and tested with refe…

Towards an efficient meshfree solver

2016

In this paper we focus on the enhancement in accuracy approximating a function and its derivatives via smoothed particle hydrodynamics. We discuss about improvements in the solution by reformulating the original method by means of the Taylor series expansion and by projecting with the kernel function and its derivatives. The accuracy of a function and its derivatives, up to a fixed order, can be simultaneously improved by assuming them as unknowns of a linear system. The improved formulation has been assessed with gridded and scattered data points distribution and the convergence has been analyzed referring to a case study in a 2D domain.

Equivalent Circuit Modelling of Ferrite Inductors Losses

2018

The modelling of the magnetic losses in the core of ferrite inductors for power conversion circuits has been considered in this paper. On the basis of the Revised Generalized Steinmetz Model (RGSE) an equivalent circuital modelling has been obtained. The losses are modelled as an equivalent resistance connected in parallel to the inductor. The model has been tested under periodic triangular current waveforms.