Search results for "iTED"

Exchange transfer in high-nuclearity mixed valence magnetic clusters: Theoretical approach and expected manifestations

1998

Abstract We report here a general solution of the exchange transfer problem in the high-nuclearity mixed valence clusters containing arbitrary number of itinerant electrons. The concept of two kinds of exchange transfer, namely kinetic and potential, is introduced by analogy with basic Anderson's mechanisms of the magnetic exchange. The kinetic exchange transfer is treated as a second order transfer process between two centres through the excited state of a third centre. The potential exchange transfer is also considered as a three-centre interaction but in this case only the ground states of the constituent ions are involved. The actual parameters of the exchange transfer are expected to b…

Startup Metrics That Tech Entrepreneurs Need to Know

2020

Metrics can be used by firms to make more objective decisions based on data. Software startups in particular are characterized by the uncertain or even chaotic nature of the contexts in which they operate. Using data in the form of metrics can help software startups to make the right decisions amid uncertainty and limited resources. However, whereas conventional business metrics and software metrics have been studied in the past, metrics in the specific context of software startups have not been studied. In this chapter, we present the results of a multivocal literature review to offer you 118 metrics practitioner experts think software startups should measure. These metrics can give you id…

Higher order statistics of the response of MDOF linear systems excited by linearly parametric white noises and external excitations

1997

The aim of this paper is the evaluation of higher order statistics of the response of linear systems subjected to external excitations and to linearly parametric white noise. The external excitations considered are deterministic or filtered white noise processes. The procedure implies the knowledge of the transition matrix connected to the linear system; this, however, has already been evaluated for obtaining the statistics at single times. The method, which avoids making further integrations for the evaluation of the higher order statistics, is very advantageous from a computational point of view.

Estudio de las noticias publicadas en prensa del éxodo de enfermeras españolas al Reino Unido

2019

RESUMEN Objetivo Analizar la representación mediática del éxodo de las enfermeras españolas al Reino Unido a través de los diarios de información general. Métodos Análisis de contenido, cuantitativo y cualitativo. Se localizaron con operadores booleanos los documentos publicados en los diarios ABC, El País, El Mundo y La Razón, sobre «emigrantes», «enfermeras» y «sanitarias emigrantes», desde el 1 de enero de 2007 hasta el 31 de diciembre de 2016. El periodo seleccionado se corresponde con el inicio de la crisis económica y concluye con el año de la celebración del referéndum delBrexiten el Reino Unido. Tras aplicar los descriptores se obtuvieron 9559 textos. Una vez eliminado el «ruido» qu…

Study on press coverage about the exodus of Spanish nurses to the United Kingdom

2019

Resumen: Objetivo: Analizar la representación mediática del éxodo de las enfermeras españolas al Reino Unido a través de los diarios de información general. Métodos: Análisis de contenido, cuantitativo y cualitativo. Se localizaron con operadores booleanos los documentos publicados en los diarios ABC, El País, El Mundo y La Razón, sobre «emigrantes», «enfermeras» y «sanitarias emigrantes», desde el 1 de enero de 2007 hasta el 31 de diciembre de 2016. El periodo seleccionado se corresponde con el inicio de la crisis económica y concluye con el año de la celebración del referéndum del Brexit en el Reino Unido. Tras aplicar los descriptores se obtuvieron 9559 textos. Una vez eliminado el «ruid…

Photophysical properties of a rhodium tetraphenylporphyrin-tin corrole dyad. The first example of a through metal-metal bond energy transfer

2005

The luminescence spectroscopy study and the determination of the photophysical parameters for the M-M'-bonded rhodium meso-tetraphenylporphyrin-tin(2,3,7,13,17,18-hexamethyl-8,12-diethylcorrole) complex, (TPP)Rh-Sn(Me6Et2Cor) 1, was investigated. The emission bands as well as the lifetimes (tau(e)) and the quantum yields (Phi(e); at 77 K using 2MeTHF as solvent) were compared with those of (TPP)RhI 2 (TPP = tetraphenylporphyrin) and (Me6Et2Cor)SnCl 3 (Me6Et2Cor = 2,3,7,13,17,18-hexamethyl-8,12-diethylcorrole) which are the two chemical precursors of 1. The energy diagram has been established from the absorption, fluorescence and phosphorescence spectra. The Rh(TPP) and Sn(Me6Et2Cor) chromop…

Unexpected photochemistry and charge-transfer complexes of [CB(11)H(12)](-) carborane.

2008

Although the [CB(11)H(12)](-) carborane does not exhibit an absorption band in UV, its triplet excited state can be generated upon 308 nm laser excitation; also unexpectedly carborane acts as electron donor forming a charge transfer complex with methylviologen that upon illumination gives rise to viologen radical cation.

15. Spectroscopic methods applied to zircon

2003

Natural and synthetic (pure and doped) zircon (ZrSiO4) have been studied with a variety of spectroscopic techniques. These techniques are based on different physical phenomena, for instance transitions between spin states of nuclei and electrons, energetic transitions of valence electrons, intra-molecular vibrations, or vibrations of atoms and molecular units in the lattice. All of the diverse spectroscopic techniques, however, have in common that they probe energy differences between a ground and excited states, mostly upon interaction of the mineral with incident radiation. Such interactions are not only determined by the excited elementary particles or molecules themselves but depend gre…

World Tuberculosis Day 2021 Theme - 'THE CLOCK IS TICKING' - and the world is running out of time to deliver the United Nations General Assembly comm…

2021

Global distribution of Mycobacterium tuberculosis spoligotypes.

2002

Since the publication of the second version of our spoligotypes database on Mycobacterium tuberculosis (1), the causative agent of tuberculosis (TB), the proportion of clustered isolates (shared types [STs]) increased from 84% (2,779/3,319) to 90% (11,708/13,008). Fifty percent of the clustered isolates were found in only 20 STs. Three of these isolates are M. bovis, including M. bovis BCG (ST 481, 482, and 683). The addition of the next 30 most frequent STs increased the total proportion of clustered isolates (65% instead of 50% initially). A total of 36 potential subfamilies or subclades of M. tuberculosis complex have been tentatively identified, leading to the definition of major and mi…