Search results for "Fig"
showing 10 items of 1359 documents
Selected dissociation‐ and correlation‐consistent configuration interaction by a perturbative criterion
1990
We propose a perturbative criterion to select the most important dissociation‐ or correlation‐consistent type of contributions to perform generalized valence bond‐configuration interaction (GVB‐CI) calculations, dissociation‐consistent configuration interaction (DCCI) or correlation‐consistent configuration interaction (CCCI) approach, respectively. The procedure presented is computationally less demanding than the CCCI proposed by Goddard and co‐workers. To ensure the distance consistency of the MOs used, the nonvalence virtual orbitals are obtained by a projection technique. The results obtained for a few test calculations show the ability of the suggested approach to get close results to…
El rol del modelo de las competencias en la reconfiguración meritocrática de las pautas de negociación salarial en empresas argentinas: continuidades…
2020
The development of new models of work organization and the complementary advance of flexible guidelines for the use of the labor force had as a correlate a profound change in techniques for the evaluation of workers. Thus, the typical model of Fordism, based on qualifications, was replaced by a different one based on competencies, whereby the strong relationship of the former was abandoned with the determination of the technical knowledge required for each job to move to a system which the priority is placed in the individual attitude. The consequent individualization of performance evaluations can lead to a possible loss of objectivity. In this article we develop a theoretical comparison b…
Stereoselective Synthesis of Chiral Piperidine Derivatives Employing Arabinopyranosylamine as the Carbohydrate Auxiliary.
2006
Stereoselective synthesis of 2-substituted dehydropiperidinones and their further transformation to variously disubstituted piperidine derivatives was achieved employing D-arabinopyranosylamine as the stereodifferentiating carbohydrate auxiliary. A domino MannichMichael reaction of 1-methoxy-3-(trimethylsiloxy)butadiene (Danishefsky's diene) with O-pivaloylated arbinosylaldimines furnished N-arabinosyl dehydropiperidinones in high diastereoselectivity. Subsequent conjugate cuprate addition gave 2,6-cis-substituted piperidinones, while enolate alkylation furnished 2,3-trans-substituted dehydropiperidinones. Electrophilic substitution at the enamine structure afforded 5-nitro- and 5-halogen…
Thermal conductivity of half-Heusler superlattices
2014
Thin films and superlattices (SLs) of TiNiSn and ZrHfNiSn layers have been grown by dc magnetron sputtering on MgO (100) substrates to reduce the thermal conductivity, aiming for improvement of the thermoelectric figure of merit ZT. The thermal conductivity of 1 Wm−1K−1 was measured by the differential 3ω method for an SL with a periodicity of 8.8 nm. In addition to x-ray diffraction analysis of the SL crystal structure, smooth interfaces were confirmed by scanning/transmission electron microscopy.
Phase separation as a key to a thermoelectric high efficiency
2012
This work elucidates the possible reasons for the outstanding, but never reproduced thermoelectric properties of the doped Ti(0.5)Zr(0.25)Hf(0.25)NiSn Heusler compounds. The structural investigations done via synchrotron X-ray diffraction measurements and scanning electron microscope measurements, which clearly show that the microstructure consists of three temperature stable C1(b) phases with possible semi-coherent interfaces, are presented. The exceptional thermoelectric properties are due to this intrinsic phase separation. It is possible to reproduce the high Figure of Merit values with ZT = 1.2 at 830 K. Furthermore, the influence of doping different elements on the Sn position in this…
Structural characterization of carane derivative stereoisomers - Potent local anesthetics
2002
The paper reports on structural investigation and phase analysis of a newly synthesized potent local anesthetic with chiral molecular structure. Absolute structure and absolute configuration on four chiral centres was determined using microcrystalline single-crystal difracti on with anomalous scattering of X-ray radiation azimuthal scan technique. Phase analysis for new compound (K P23SS) and its epimer (K P23 RS) was carried out using classical and synchrotron radiation powder difraction. Enantiopurity of the bulk material was verifed for both isomers by comparison of experimental and simulated high- resolution powder difraction diagrams. The presence of two new polymorphic phases of K P23…
Magic numbers, excitation levels, and other properties of small neutral math clusters (N < 50)
2006
The ground-state energies and the radial and pair distribution functions of neutral math clusters are systematically calculated by the diffusion Monte Carlo method in steps of one math atom from 3 to 50 atoms. In addition the chemical potential and the low-lying excitation levels of each cluster are determined with high precision. These calculations reveal that the “magic numbers” observed in experimental math cluster size distributions, measured for free jet gas expansions by nondestructive matter-wave diffraction, are not caused by enhanced stabilities. Instead they are explained in terms of an enhanced growth due to sharp peaks in the equilibrium concentrations in the early part of the e…
The UN in the Lab
2013
We consider two alternatives to inaction for governments combating terrorism, which we term Deterrence and Prevention. Deterrence – investing in resources that reduce the impact of an attack – generates a negative externality to other governments, making their countries a more attractive objective for terrorists, while Prevention – investing in resources that reduce the ability of the terrorist organization to mount an attack – creates a positive externality by reducing the overall threat of terrorism for all. Due to the structure of this interaction, countries can benefit from coordination of policy choices, and international institutions (such as the UN) can be utilized to facilitate coor…
Recensione a Annalisa Carbone, Dipingere e scrivere per me sono la stessa cosa. Dino Buzzati tra parola e immagine, Soveria Mannelli, Rubettino, 2016.
2018
La sfida proposta dal volume di Carbone è ambiziosa perché intende analizzare all’interno dell’opera buzzatiana quattro macro-questioni che intrecciano scritture e immagini, dedicando a ciascuna di esse un preciso capitolo: Buzzati critico d’arte, Buzzati e le forme estetiche di massa, L’immaginario dipinto di Dino Buzzati, Buzzati disegnatore.
Probability Propagation in Selected Aristotelian Syllogisms
2019
This paper continues our work on a coherence-based probability semantics for Aristotelian syllogisms (Gilio, Pfeifer, and Sanfilippo, 2016; Pfeifer and Sanfilippo, 2018) by studying Figure III under coherence. We interpret the syllogistic sentence types by suitable conditional probability assessments. Since the probabilistic inference of $P|S$ from the premise set ${P|M, S|M}$ is not informative, we add $p(M|(S ee M))>0$ as a probabilistic constraint (i.e., an ``existential import assumption'') to obtain probabilistic informativeness. We show how to propagate the assigned premise probabilities to the conclusion. Thereby, we give a probabilistic meaning to all syllogisms of Figure~III. We…