The accessibility to employment offices in the Spanish labour market*

This paper focuses on the differences in the levels of accessibility to public employment offices in the Spanish municipalities. Hence the main purpose is to evaluate the role of the public employment services in local labour markets by considering the physical distance to employment offices and the spatial structure of their catchment areas. First, we propose an accessibility measure and, second, we estimate a spatial model and test whether a higher accessibility to employment offices could contribute to reduce local unemployment rates. The results suggest that policy‐makers should strive to improve the accessibility to employment offices so that adequate assistance to find suitable employment may be ensured to every jobseeker. Resumen Este artículo se centra en las diferencias en los niveles de accesibilidad a las oficinas públicas de empleo en los municipios españoles. El objetivo principal es por tanto evaluar el papel de los servicios públicos de empleo en los mercados laborales locales, en función de la distancia física a las oficinas de empleo y la estructura espacial de sus zonas de influencia. Primero, se propone una medida de accesibilidad y, a continuación, se estima un modelo espacial y se comprueba si una mayor accesibilidad a las oficinas de empleo podría contribuir a reducir las tasas de desempleo local. Los resultados sugieren que los responsables de formular políticas deberían esforzarse por mejorar la accesibilidad a las oficinas de empleo, a fin de poder asegurar a cada demandante de empleo la ayuda apropiada para que logre encontrar un empleo adecuado.      

Thermal properties of polynorbornene (cis- and trans-) and hydrogenated polynorbornene

Summary The thermal properties of trans-polynorbornene, cis-polynorbornene and hydrogenated polynorbornene were examined and its reversibility tested. Trans-polynorbornene samples, formed in various solvents, exhibit a softening range, from ambient temperature until 375 °C. However, syndiotactic cis-polynorbornene samples show a narrower melting range (between 150 and 375 °C). The fusion enthalpies of cis-polynorbornene samples are around 300-400 J/g. The temperature of decomposition is ca. 456 °C (minimum peak DSC) for trans-polynorbornene and ca. 466 °C, 10 °C higher, for cis-polynorbornene. The solvent used for the polymerization of norbornene has a negligible influence in the melting temperature range or in the decomposition temperature. The treatment with 2,6-di-tert-butyl-4-methyl-phenol during the isolation of polynorbornene leads to materials with different thermal properties. Trans-polynorbornene isolated without 2,6-di-tert-butyl-4-methyl-phenol exhibited an exothermic peak accompanied by an slight increase in weight (1-2%), while samples treated with 2,6-di-tert-butyl-4-methyl-phenol do not show these features.     

Total Oxidation of Naphthalene Using Mesoporous CeO2 Catalysts Synthesized by Nanocasting from Two Dimensional SBA-15 and Three Dimensional KIT-6 and MCM-48 Silica Templates

Ceria catalysts have been prepared by a nanocasting procedure using SBA-15, MCM-48 and KIT-6 silica-based templates, and investigated for the total oxidation of naphthalene. In all cases cubic fluorite CeO₂ was prepared, and the structure of the template was replicated when SBA-15 and MCM-48 were used. The KIT-6 template was not replicated by the nanocasting synthesis, but in all cases mesoporous CeO2 was obtained with high surface areas (91–190 m² g^?1). All of the catalysts demonstrated high activity for naphthalene oxidation to CO₂, and the most active was the catalyst prepared from the KIT-6 template. The high activity was attributed to the small crystallite size of the CeO₂, combined with high surface area and the highly accessible catalyst surface.     

Thermogravimetric study of thermal degradation of polyetherimide

Thermal stability in nonoxidizing atmosphere of a polyetherimide (PEI) is investigated by thermogravimetry (TG). It is observed that thermal degradation of this product consists of two overlapping processes, which are conveniently separated by fitting the TG curves to mixtures of generalized logistic functions. Thus, each process is represented by a single function. The analysis of the fitting parameter values obtained for the main degradation process in different isothermal and heating ramp conditions allows to obtain insightful kinetic parameters (critical temperature, energy barrier, and reaction‐order) which allow to make predictions in both isothermal and nonisothermal contexts. There is a minimum temperature for each process to occur and a ramp‐energy barrier related to the process rate. In the ramp context, the values of these two parameters explain that, although one process starts at lower temperature, it proceeds at a very low rate until reaching temperatures at which the other process goes much faster. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42329.     

Realization of the kilogram by measuring at 100 kV with the voltagebalance ETF

The possibilities for adapting the existing electrostatic device known as the voltage balance ETF-84, to work with a voltage of 100 kV and a weight of 1 kg, are considered. A few theoretical analyses, experiments, and computer simulations have been carried out to define the measurement procedure needed at the required level of uncertainty of 1 part in 10⁸. These analyses identified which parts of the balance itself and of the high voltage electrode isolation have to be reconstructed, as well as how the associated high voltage resistor has to be designed for this purpose     

Changes in phenolic compounds in lentils (Lens culinaris) during germination and fermentation

 Germination and fermentation have been proposed to improve the nutritive value of legumes. This paper reports the changes that occur in phenolic compounds in lentils (Lens culinaris var. vulgaris) during germination and fermentation. Levels of low-molecular-weight phenolic compounds (benzoic acids and aldehydes, hydroxycinnamic acids and derivatives, flavan-3-ols and procyanidins) were determined. Germination did not appreciably vary the content of phenolic compounds, although important structural changes in procyanidin-type compounds were observed. Fermentation led to a general increase in the content of phenolic compounds. Gentisic acid, p-hydroxyphenylpropionic acid, tryptophol and three other unknown compounds were detected in fermented lentils, but not in raw lentils. The influence of these changes on the potential antinutritional effects associated with phenolic compounds in legumes, as well as on the antioxidant properties attributed to these compounds is discussed. Received: 16 December 1996 / Revised version: 6 March 1997     

Comparative study of the inhibitory effects of wine polyphenols on the growth of enological lactic acid bacteria

This paper reports a comparative study of the inhibitory potential of 18 phenolic compounds, including hydroxybenzoic acids and their derivatives, hydroxycinnamic acids, phenolic alcohols and other related compounds, stilbenes, flavan-3-ols and flavonols, on different lactic acid bacteria (LAB) strains of the species Oenococcus oeni, Lactobacillus hilgardii and Pediococcus pentosaceus isolated from wine. In general, flavonols and stilbenes showed the greatest inhibitory effects (lowest IC?? values) on the growth of the strains tested (0.160-0.854 for flavonols and 0.307-0.855 g/L for stilbenes). Hydroxycinnamic acids (IC?? > 0.470 g/L) and hydroxybenzoic acids and esters (IC?? >1 g/L) exhibited medium inhibitory effect, and phenolic alcohols (IC?? > 2 g/L) and flavanol-3-ols (negligible effect) showed the lowest effect on the growth of the LAB strains studied. In comparison to the antimicrobial additives used in winemaking, IC?? values of most phenolic compounds were higher than those of potassium metabisulphite for O. oeni strains (e.g., around 4-fold higher for quercetin than for potassium metabisulphite), but lower for L. hilgardii and P. pentosaceus strains (e.g., around 2-fold lower for quercetin). Lysozyme IC?? values were negligible for L. hilgardii and P. pentosaceus, and were higher than those corresponding to most of the phenolic compounds tested for O. oeni strains, indicating that lysozyme was less toxic for LAB than the phenolic compounds in wine. Scanning electron microscopy confirmed damage of the cell membrane integrity as a consequence of the incubation with antimicrobial agents. These results contribute to the understanding of the inhibitory action of wine phenolics on the progress of malolactic fermentation, and also to the development of new alternatives to the use of sulphites in enology.     

Effect of combined treatments of high-pressure and natural additives on carotenoid extractability and antioxidant activity of tomato puree (<Emphasis Type="Italic">Lycopersicum esculentum</Emphasis> Mill.)

High-pressure is a new food processing technology aimed at achieving consumer demands for fresher products with reduced microbiological levels. The objective of this work was to evaluate the effect of combined treatments of high-pressure and natural additives (citric acid and sodium chloride) on lutein, lycopene, lycopene epoxide, - and -carotene content, and vitamin A value, and on the in vitro antioxidant activity of tomato puree. The methods used to evaluate the antioxidant activity were the measurement of the DPPH· radical scavenging and the inhibition of lipid oxidation (linoleic acid/CuSO₄ system). The experimental design comprised a response surface methodology according to a central composite face-centred design. The variable ranges were 50–400 MPa, sodium chloride 0–0.8%, and citric acid 0–2%. Total carotenoid content showed the best extraction when pressure was increased up to 400 MPa without sodium chloride and citric acid. The effect of the moderately high-pressure treatment (under 200 MPa) on the structure of the cellular tomato matrix may lead to the different release of various carotenes on the basis of their chemical features and chromoplast location. Radical scavenging activity was higher in the aqueous extract than the organic extract of tomato puree. Significant correlation (P<0.05) was found between the total carotenoid content and the radical scavenging activity and inhibition of lipid oxidation by the organic extract of tomato puree. In conclusion, applying the highest range of pressures (without additives) increased the carotenoid extractability. Further human studies are needed to clarify the effect of high-pressure treatment on the bioavailability of tomato puree constituents.