Publications

Abstract Consumers and industrial activities increasingly require goods and services that suit as much as possible to their needs and tastes. The footwear industry has followed these trends leading to the need to use a variety of materials and components that are presently used from casual shoes to technical products such as safety and protective footwear. Rubber is among these materials and has been strongly used in the production of shoe soles since its discovery in 1837 by Goodyear. Although rubber, more precisely vulcanized rubber, present some drawbacks in comparison with other polymers used in footwear applications (e.g. higher density, longer processing operations and slightly higher costs) it gathers a group of superior physical properties suitable for shoe sole production, namely, durability, abrasion resistance, tensile resistance, tear strength resistance, slip resistance, oil resistance and the ability to be molded in different colors. This chapter focuses on the properties and physical-mechanical guidelines for vulcanized rubber applications in footwear and on the description of recent developments regarding shoe sole applications. In particular the work carried out in shock absorption properties in vulcanized rubber, natural rubber incorporating mercerized natural fibers of sisal, jute, hemp and bamboo will be presented.

Abstract We have performed high level ab initio quantum mechanical calculations for aminoethene and the three isomeric 1,1- (Z)- or (E)-1,2-diaminoethenes as well as their singly and doubly charged cations derived by loss of electrons and/or upon protonation. Gas phase molecular structures were computed at the MP2/6-311+G(3df,2p) level. Standard molar enthalpies of formation in the gas phase, at T=298.15K, were estimated using the G3 composite method and atomization, isodesmic and homodesmotic reactions. Other energetic parameters were also calculated at the G3 level: proton affinities, basicities and adiabatic ionization enthalpies. Theoretical and experimental data are compared. The reported experimental data refer only to aminoethene wherein the standard molar enthalpy of formation has a considerable uncertainty, although the molecular structure is well established. There are no such data, neither structural nor thermochemical, for any of the three isomeric diaminoethenes. Isoelectronic comparisons are made. For example, the diprotonated diaminoethenes are isoelectronic to isobutene and (Z)- and (E)-butene, while the doubly ionized diaminoethenes are likewise related to trimethylenemethane and 1,3-butadiene. Copyright (c) 2013 John Wiley & Sons, Ltd.

Abstract The unimolecular decomposition of 1,2-dioxetanedione, the high-energy intermediate of the chemiluminescence peroxyoxalate reaction, was studied by theoretical means for the first time. Our calculations have provided results in line with the experimental data regarding this compound. 1,2-Dioxetanedione decomposes due to a step-wise biradical mechanism. In the biradical region of the decomposition path, there is a path for singlet chemiexcitation. Interactions between the singlet ground and excited states with triplet states can explain the weak unimolecular chemiluminescence of 1,2-dioxetanedione. Copyright (c) 2013 John Wiley & Sons, Ltd.

Abstract Firefly bioluminescence has attracted much attention from the research community due to its most intriguing multicolor bioluminescence. Computational studies have been fundamental to the clarification of this phenomenon. However, no clear demonstration of the accuracy of the theoretical methods used in this field of research has been provided. In this work, we have used luciferin and dehydroluciferin in water as a model for the calculation of the emission wavelength of oxyluciferin and analogs. This model was used in a density functional theory (DFT) benchmarking in which 24 functionals were tested. A non-negligible case to case dependence was observed. However in general, the better classes of the DFT functionals are generalized gradient approximation (GGA) and meta GGA. The generalized gradient exchange functional TPSSVWN5, the hybrid-meta GGA functional mPWKCIS, and the hybrid GGA functional MPWLYP1M also present good results. For the contrary, the popular hybrid GGA functionals present a worse performance. (c) 2012 Wiley Periodicals, Inc.

Abstract The chemiluminescence of simple 1,2-dioxetanone has already been studied by both multiconfigurational and density functional theory calculations. The former approach revealed a step-wise biradical mechanism for its decomposition, whereas the latter revealed a concerted mechanism. The first approach was not in line with both computational and experimental findings, whereas the second mechanism was. Due to these apparent mechanistic contradictions and some concerns regarding our concerted mechanism, and the use of a closed-shell approach and different methods for geometry and single-point calculations, we have revisited the chemiluminescence of this molecule. Once again the concerted mechanism was found to be prevailing, and a closed-shell approach was able to rationalize the chemiluminescence of 1,2-dioxetanone. It was once again noted that an open-shell and a step-wise biradical mechanism cannot explain the chemilu minescence of this molecule. (C) 2013 Wiley Periodicals, Inc.

Abstract A fluorescent hybrid material (PPH-S-CdSe), which comprises cadmium selenide sulphide nanoparticles assembled onto thiol functionalised porous phosphate heterostructures (PPH-SH), was synthesised in aqueous media. This material presents a high stability towards photo-degradation. The obtained nanocomposite was characterised by various techniques such as Fourier transform infrared spectroscopy, energy dispersive X-ray, transmission electron microscopy (TEM), X-ray diffraction, X-ray photoelectron spectroscopy and fluorescence spectroscopy. This fluorescent material showed a red emission at 576nm combined with other at 473nm, explained as different CdS0.42Se0.58 nanoparticles size, supported by TEM images. It was suitable for latent fingermark analysis in a wide range of surfaces. Because of its sensitivity and low cost, it is an actual alternative to conventional powdering materials. Copyright (C) 2012 John Wiley & Sons, Ltd.

Abstract We have performed high level ab initio quantum chemical calculations for 2- and 3-pyrrolidinone; tetrahydro-2- and -3-furanone; 2-, 3-, and 4-piperidinone; and tetrahydro-2-, -3-, and -4-pyranone. The most stable molecular structures were obtained from DFT calculations using the B3LYP density functional and the 6-31G(d) and 6-311+G(3df,2p) basis sets. The respective enthalpies of formation have been computed by the G3(MP2)//B3LYP composite method and appropriately chosen reactions. The calculated results are in excellent agreement with experimental data reported in the literature.

Abstract The standard (p = 0.1 MPa) molar enthalpy of formation of 6,7-dihydro-4(5H)-benzofuranone was measured, at T = 298.15 K, by static bomb calorimetry and the standard molar enthalpy of vaporization, at T = 298.15 K, was obtained using Calvet microcalorimetry. These values were combined together to derive the standard molar enthalpy of formation of the title compound in gaseous phase, at T = 298.15 K, -(226.0 +/- 2.8) kJ . mol (1). [GRAPHICS] Additionally, density functional theoretical calculations using the B3LYP hybrid exchange-correlation energy functional with extended basis sets and also other higher-level ab initio quantum calculations have been performed.

Abstract We have performed a study of the structure and energetics of some chlorohydroxypyridines based on experimental calorimetry techniques and high level ab initio computational calculations. The standard (p degrees = 0.1 MPa) molar enthalpies of formation of 2-chloro-3-hydroxypyridine (2-Cl-3-OHPy), 2-chloro-6-hydroxypyridine (2-Cl-6-OHPy) and 3-chloro-5-hydroxypyridine (3-Cl-5-OHPy) in the crystalline phase, at T = 298.15 K, were derived from the respective standard massic energies of combustion measured by rotating-bomb combustion calorimetry, in oxygen, at T = 298.15 K. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by Calvet microcalorimetry. From these experimentally determined enthalpic parameters we have derived the standard molar enthalpies of formation of the three compounds in the gaseous phase, at T = 298.15 K: 2-Cl-3-OHPy, -(76.8 +/- 2.0) kJ . mol(-1); 2-Cl-6-OHPy, -(105.0 +/- 1.7) kJ . mol(-1), 3-Cl-5-OHPy -(61.2 +/- 2.4) kJ . mol(-1). These values were compared with estimates obtained from very accurate computational calculations using the G3(MP2)//B3LYP composite method and appropriately chosen reactions. These calculations have also been extended to the remaining chloro hydroxypyridine isomers that were not studied experimentally. Based on B3LYP/6-31G* optimized geometries and calculated G3(MP2)//B3LYP absolute enthalpies some structure-energy correlations were discussed.

Abstract The measurement of serum C-reactive protein (CRP) levels has been given particular interest as a marker of inflammation associated with cardiovascular diseases. CRP belongs to the pentraxin family of proteins and the routine clinical analysis of CRP in blood samples is used as an important factor in primary prevention programmes together with causative and predisposing factors. This review focuses on the most representative methodologies and strategies for CRP detection and quantification that have been recently proposed, as well as reviewing those that are currently being developed for the specific, sensitive, inexpensive and high-throughput blood analysis of this protein.