Brillouin scattering from epoxy resins and gels

Summary The isothermal curing process of the system diglycidyl ether of Bisphenol A/poly (oxypropylene) diamine (Jeffamine D-400) without and in the presence of solvent (Diglyme) was investigated by Brillouin spectroscopy for the stoichiometric amounts of epoxide and amine groups. The spectroscopic data have been explained in terms of the relaxing viscosity model in the former case and by the scattering of phonons by stationary heterogeneities in the latter one. It is suggested that these heterogeneities may be small air bubles released during curing and frozen in due to the high viscosity at and above the gel point.     

The inhibition of the viability of myeloma cells and the production of cytokine by two strains of Lactobacillus sakei from meat

Ten strains of lactic acid bacteria were isolated from a dry fermented sausage and tested for stimulation or inhibition of the viability of Vero and myeloma cells. They did not significantly affect the viability of Vero cells but two isolates (CBL/H and CBL/K) showed a strong and moderate inhibition of the myeloma cell viability (at 10⁸ CFU mL^?1, 17.6 and 33.2%, respectively, survival of myeloma cells). The isolates were identified as Lactobacillus sakei by DNA sequencing of the 16S rRNA products of a polymerase chain reaction. No protective effect was found, at the concentrations used, against cytotoxicity of N‐nitrosamines. To test the effect of L. sakei CBL/H and CBL/K on cytokine production [tumour necrosis factor alpha (TNF‐α), interleukin‐1β (IL‐1β) and interleukin‐8 (IL‐8)], the human macrophage cell line (THP‐1) was cultured in the presence and absence of lipopolysaccharide (LPS). Lactobacillus sakei CBL/H and CBL/K induced IL‐1β and IL‐8 release when cells were stimulated with and without LPS. However there was TNF‐α release only in the presence of the LPS.     

Scattering of electrons in beta-spectroscopy sources

Experimental spectra of the¹⁶⁹Yb conversion lines having kinetic energies of 3.7–18.4 keV and the beta spectrum from the decay of²⁴¹Pu are compared with calculations by the Monte Carlo method which take into account the individual elastic and inelastic scattering processes of the electrons in the source, in the substrate, and in a carbon layer contaminating the source. Good agreement is obtained between the theoretical and experimental results. It is also shown that the scattering of the electrons depends on their emission angle. Translated from Izmeritel'naya Tekhnika, No. 8, pp. 63–65, August. 1997.     

Spatial model selection strategies in a SUR framework. The case of regional productivity in EU

The purpose of the paper was to compare two well-known model selection strategies, the so-called Specific-to-General, Stge, and General-to-Specific, Gets, in a context of spatial SUR models. The two strategies use a battery of misspecification tests obtained in a maximum likelihood framework. The robust tests to local misspecification errors in the alternative hypothesis and the common factor test have been developed with this purpose. The paper includes a Monte Carlo experiment to compare their performance in a situation of small sample sizes. The results are mixed: Both alternatives work well under ideal conditions, but their efficiency deteriorates for different departures such as non-normality or endogeneity. All in all, Stge appears to be slightly preferable although our impression is that the two are complementary and can be used in common. The paper finishes with an application to the case of productivity for a large set of European regions.     

Impact of road safety interventions on traffic-related occupational injuries in Spain, 2004–2010

Objectives

To evaluate the impact of road safety interventions, including the penalty point system (PPS) and the reformed Spanish penal code (RPC), on traffic-related occupational injuries in Spain.

Methods

The study design was an interrupted time-series with a comparison group. The study group had traffic-related, occupational injuries incurred during working and commuting hours; the comparison group had non-traffic-related injuries incurred at the work site. A negative binomial regression model was used to determine the relative risk (RR) of sustaining occupational injuries for the post-intervention periods compared to the non-intervention period.

Results

Non-fatal, traffic-related injuries did not significantly change after the PPS and RPC implementations, except for those occurred in commuting hours, which increased significantly after the PPS. On the other hand, after the RPC, fatal, traffic-related injuries decreased significantly during working hours (0.79; 95%CI 0.65 to 0.97) and commuting hours (RR: 0.63; 95%CI:0.56 to 0.72), although fatal, non-traffic-related injuries also decreased at the work site.

Conclusions

Road safety interventions did not clearly affect traffic-related occupational injuries in Spain. Specific occupational risk factors could influence the occurrence of those injuries.     

Thermal Properties of Phase Change Materials

This contribution deals with a study of the thermal properties of systems which consist of different types of materials: poly(methyl methacrylate) (PMMA), thermal insulator \({\mathrm{Aerotherm}^{\circledR }}\) , and phase change material \({\mathrm{Micronal}^{\circledR }}\) . The aim of this study is to evaluate the ability of these materials to decrease the working temperature of solar cells and therefore to increase their quantum efficiency. Step-wise and pulse transient methods were used for the determination of thermal parameters, such as the thermal conductivity, thermal diffusivity, specific heat, heat source quality, and heat losses. For the calculation of thermophysical parameters, a fractal theory of physical fields was used. For the determination of the parameters of the fractal model, a multi-parametric regression method was used. The experimental and theoretical results are in good agreement.     

Recycling of solid waste rich in organic nitrogen from leather industry: mineral nutrition of rice plants

The leather industry produces a large quantity of solid waste (wet blue leather), which contains a high amount of chromium. After its removal from wet blue leather, a solid collagenic material is recovered, containing high nitrogen levels, which can be used as a nitrogen source in agriculture. In order to take more advantage of the collagen, it was enriched with mineral P and K in order to produce NPK formulations. The objective was also to evaluate the efficiency of such formulations as a nutrient supply for rice plants in an Oxisoil, under greenhouse conditions. The application of PK enriched-collagen formulations resulted in N contents in the vegetative parts and grains of rice plants which were equivalent or superior to those obtained with urea and commercial NPK formulations.     

Zinc oxide/carboxylic acid lamellar structures

Hybrid organic–inorganic semiconductor nanocomposites of layered zinc oxide/carboxylic acids were fabricated. Products are pure phases with structures constituted by double-layer sheets of the inorganic component sandwiched between self-assembled surfactant layers. The optical properties of the nanocomposites are found to be qualitatively similar to those of bulk zinc oxide. However, blue shifted absorption band edges and enhanced band-gap energies are observed. The photocatalytic activity of the products in the degradation of methylene blue indicates that the efficiency of the nanocomposites is comparable or even better than that of bulk oxide.