DNA - novel nanomaterial for applications in photonics and in electronics

Functionalization with surfactants and with active molecules of deoxyribonucleic acid (DNA), thin film processing as well as their nonlinear optical and electrical properties are reviewed and discussed. On the basis of a quantum three level model, we show that the anomalous concentration variation of cubic susceptibility chi((3))(-3 omega; omega, omega, omega) in thin films of DNA-CTMA complexes doped with Disperse Red 1 chromophore can be explained by the concentration variation of two-photon resonance contribution. We show also that the DNA complexes, plasticized with glycerol and adequately doped can be processed into self standing conducting membranes with a high electrical conductivity. The measured ionic conductivity at room temperature, depending on dopant used and its concentration, is in the range of 3.5 x 10(-4)-10(-5) S/cm and increases linearly as a function of temperature, reaching 10(-3) S/cm at 358 K for the most conducting sample, obeying predominantly the Arrhenius law. Practical applications of DNA complexes are also described and discussed. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Delivery Levels of Support Competencies to Organizational Eco-efficiency: a case study in an electro-electronics sector industry

This article aims to develop and implement a search tool which, through the perception of its respondents, allows assessing how eco-efficient an organization is based on the identification of delivery levels of support competencies to organizational eco-efficiency. A mixed (qualitative and quantitative) exploratory-descriptive research was conducted, from a case study in an 'ISE Company'. A semi-structured interview and pictures of verification were used as data collection instruments. The data were analyzed via documentary analysis and triangulation of information collected. It was inferred that at the 'ISE Company' professionals at the high-level of the organizational hierarchy recognize, in part, the growth of organizational actions that contribute to sustainability, which is not fully consistent with national publications on the subject. The result of the research showed that organizational strategies addressing eco-efficiency are partially aligned with the professional performance of the organization.

Electronics and Optics of Graphene Nanoflakes: Edge Functionalization and Structural Distortions

The effects of edge covalent functionalization on the structural, electronic, and optical properties of elongated armchair graphene nanoflakes (AGNFs) are analyzed in detail for a wide range of terminations, within the framework of Hartree-Fock-based semiempirical methods. The chemical features of the functional groups, their distribution, and the resulting system symmetry are identified as the key factors that determine the modification of strutural and optoelectronic features. While the electronic gap is always reduced in the presence of substituents, functionalization-induced distortions contribute to the observed lowering by about 35-55% This effect is paired with a red shift of the first optical peak, corresponding to about 75% of the total optical gap reduction. Further, the functionalization pattern and the specific features of the edge-substituent bond are found to influence the strength and the character of the low-energy excitations. All of these effects are discussed for flakes of different widths, representing the three families of AGNFs.