Anaplasmose bovina.

bitstream/item/143029/1/2049.pd

Online business-to-business communication and online relationship: The mediator role of trust

The main purpose of this study is to examine the influence of online personalised content and interactive content communication on online relationship through trust as an affective mediator in a Business-to-Business (B2B) context. A quantitative research approach was conducted using structural equation modelling and a sample of B2B reseller market of information technology in Portugal. Results indicate that online communication influences positively online relationship through trust. Interactive content has a strong influence on trust, whereas the personalised content revealed a weak relationship with trust and, indirectly, with online relationship. Trust has an important role in the relationship as it is a full mediator. In addition, the interactive content is more influential than the personalised content in building and maintaining online relationships in the B2B reseller market.info:eu-repo/semantics/submittedVersio

Electrochemical characterization of a novel salen type modified electrode

The nickel(II) complex with H2saltMe, a N2O2 Schiff base ligand derived from salicylaldehyde, was oxidatively electropolymerized on Pt electrodes in CH3CN/0.1 mol dm-3 tetraethylammonium perchlorate (TEAP) to generate polymer films that exhibit reversible oxidative electrochemical behavior in a wide potential range (0.0-1.3 V), high conductivity, and stability/durability

Oxidation of ferrocene derivatives at a Poly[Ni(saltMe)] modified electrode

The characterization of film permeability and mediation properties of poly[Ni(saltMe)] modified electrodes were evaluated by studying the oxidation of ferrocene and 1,1’-dimethylferrocene at these electrodes by rotating-disk voltammetry. The effects of varying the substrate and its solution concentration, film thickness, rotation speed and electrode potential on the limiting current density were analysed using the model of Albery

A voltammetric tool for the evaluation of propolis antioxidant activity

Propolis (bee glue) is a sticky dark-colored material that honeybees collected from parts of plants, buds and exudates, and used as construction and defense material in the hive. This resinous substance is a rich source of phenolic compounds, and its chemical composition is strongly influenced by its phytogeographic origin. This research outlines the evaluation of the redox profile and the quantification of the total antioxidant capacity in Portuguese propolis from different origins and potential floral sources Populus x canadensis Moench and Cistus ladanifer L through cyclic voltammetry and differential pulse voltammetry. Although several oxidation processes were showed by propolis samples, which were dependent of the resin origin, common oxidation potentials within the majority of samples of a region were detected, suggesting an analogous chemical composition in respect of electroactive species. Based on the quantification of the total electroactive antioxidant power, it was found that propolis with higher antioxidant activity was from coast center, followed by north ~ Azores Archipelago > central interior > Madeira Island > south.Soraia I. Falcão thanks Foundation for Science and Technology (FCT) for the PhD grant SFRH/BD/44855/2008, financially supported by POPH-QREN and FSE. Thanks also to FCT for financial support provided to CIMO (PEst-OE/AGR/ UI0690/2011). Thanks to National Federation of Portuguese Beekeepers for propolis samples.info:eu-repo/semantics/publishedVersio

Electrical and thermal properties of polyurethane/carbon nanotubes composites

The aim of this work was to study the effect of dispersing small amounts of CNT on the thermal diffusivity and electrical resistivity of PU/CNT composites. The PU nanocomposites were prepared with 0.5% and 1% weight of CNT. The composites were prepared by dispersion of the CNT in poly(propylene glycol) (PPG) followed by in situ polymerization, by mixing with 4,4′-Methylene di-p-phenyl diisocyanate (MDI). The PPG was characterized by an average molecular weight of 425 g/mol and a hydroxyl value 250 to 276 mg KOH/g. The MDI was characterized by a isocianate value (%NCO value) of 27.9-29.2. It was observed that the thermal diffusivity slightly increased with the addition of the CNT, but the results obtained were within the typical range for polymers (in the order of 10-8 m2/s). The electrical resistivity measured for the composites showed a large decrease after the addition of 0.5% and 1% of CNT. The electrical resistivity decreased 3 and 7 decades (from 109 .m to 106 and 103 .m) for 0.5 and 1% CNT composites, respectively. Thus, the composite bearing 1% of CNT dispersed in the PU presented semiconductor behaviour