Bifurcated polarization rotation in bismuth-based piezoelectrics

ABO3 perovskite-type solid solutions display a large variety of structural and physical properties, which can be tuned by chemical composition or external parameters such as temperature, pressure, strain, electric, or magnetic fields. Some solid solutions show remarkably enhanced physical properties including colossal magnetoresistance or giant piezoelectricity. It has been recognized that structural distortions, competing on the local level, are key to understanding and tuning these remarkable properties, yet, it remains a challenge to experimentally observe such local structural details. Here, from neutron pair-distribution analysis, a temperature-dependent 3D atomic-level model of the lead-free piezoelectric perovskite Na0.5Bi0.5TiO3 (NBT) is reported. The statistical analysis of this model shows how local distortions compete, how this competition develops with temperature, and, in particular, how different polar displacements of Bi3+ cations coexist as a bifurcated polarization, highlighting the interest of Bi-based materials in the search for new lead-free piezoelectrics

Default Probability Estimation via Pair Copula Constructions

In this paper we present a novel Bayesian approach for default probability estimation. The methodology is based on multivariate contingent claim analysis and pair copula theory. Balance sheet data are used to asses the rm value and to compute its default probability. The rm pricing function is obtained via a pair copula approach, and Monte Carlo simulations are used to calculate the default probability distribution. The methodology is illustrated through an application to defaulted rms data

Effects of low doses of dexamethasone on productive traits and meat quality of veal calves

An experimental administration of dexamethasone was carried out on 15 veal calves in order to assess the rôle of low doses of exogenous glucocorticoids on productive traits and meat quality. Three groups, of five veal calves each, were formed : one group received oral dexamethasone (0.4 mg per calf per day for 25 days), another intramuscular (i. m.) dexamethasone (2 mg at days 14 and 21), and the third was the control. Calves were slaughtered at 165 days of age (day 31). Food conversion ratio (FCR), hot dressing percentage (HDP), chilled dressing percentage (CDP) and shrinkage were determined. From all carcasses, samples of m. longissimus thoracis (between the 8th and 10th rib) were taken in order to evaluate the chemical composition and some organoleptic characteristics : meat colour, water-holding capacity and tenderness. The animals treated with oral dexamethasone showed the lowest daily weight gain (P < 0.05) and the poorest FCR (P < 0.05). Hot dressing percentage, cold dressing percentage and shrinkage were not affected by the oral treatment. The i. m. injections of dexamethasone did not influence the overall performance. Muscle chemical composition and pH were not affected by the treatments; the meat of calves treated with oral dexamethasone was significantly lighter (P < 0.05) and tended to be paler, while i. m. treatment induced intermediate characteristics. The shear force of the meat was rather low. Shear force of cooked meat from animals treated with dexamethasone (both oral and i. m.) was significantly lower than the control (P < 0.05). Treatment with dexamethasone i. m. induced a decrease in water-holding capacity; the oral treatment had no effect on this parameter

Gli enzimi pectolitici del mosto

Nel mosto d'uva esiste una pectinmetilesterasi aspecifica, la quale determina la demetossilazione sia delle pectine del mosto, sia di pectine di altra origine aggiunte al mosto.L'andamento della demetossilazione è quello di una reazione monomolecolare con coefficiente di temperatura Q10&lt;2.Il fatto che la demetossilazione enzimatica delle pectine segua l'andamento di una reazione del primo ordine permette una semplice e significativa valutazione dell'attività della PME nel mosto.Il mosto contiene inoltre una poligalatturonasi specifica che attacca le pectine naturali del mosto stesso, ma è incapace di idrolizzare pectine di origine diversa.I dati sperimentali avvalorano ancora l'esistenza di una protopectinasi nel mosto; tuttavia, specie a causa delle piccole concentrazioni in gioco, l'attività protopectinasica non appare sicuramente dimostrata

Liquid Foam-Ethyl Vinyl Acetate Adhesive Systems for Lining Process of Paintings: Prospects of a User-Friendly, Harmless Alternative to Conventional Products

The lining of paintings is a process of conservation science and art restoration used to strengthen, flatten, or consolidate paintings on canvas by attaching by means of adhesives a second canvas to the back of the existing one. To this aim, the prospects of the use of ethyl vinyl acetate (EVA) resins in aqueous dispersion applied as an adhesive in a foam form have been investigated in the present study. The key physical properties of the foam have been investigated, with a deep focus on rheological behavior and the drying rate, comparing the results with those obtained using the liquid products that are commercially available. Dedicated mock-ups have been prepared to test the adhesive for the lining process, inspecting adhesion strength, colorimetric properties, and the influence on the possible chromatic and visual alteration of the surface, also looking at the chemical interaction with painting materials and the deterioration after an artificial ageing process. The results obtained clearly indicated that the proposed technology is very suitable for the targeted application, and an EVA water-based foamed dispersion can be used for paintings' lining, in view of the ease of application, being an appropriate adhesion, no chemical interaction, nor the deterioration of the painting

Melamine contamination of dairy products in China – public health impact on citizens of the European Union

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Geoengineering and the Science Communication Environment: A Cross-Cultural Experiment

We conducted a two-nation study (United States, n = 1500; England, n = 1500) to test a novel theory of science communication. The cultural cognition thesis posits that individuals make extensive reliance on cultural meanings in forming perceptions of risk. The logic of the cultural cognition thesis suggests the potential value of a distinctive two-channel science communication strategy that combines information content (“Channel 1”) with cultural meanings (“Channel 2”) selected to promote open-minded assessment of information across diverse communities. In the study, scientific information content on climate change was held constant while the cultural meaning of that information was experimentally manipulated. Consistent with the study hypotheses, we found that making citizens aware of the potential contribution of geoengineering as a supplement to restriction of CO2 emissions helps to offset cultural polarization over the validity of climate-change science. We also tested the hypothesis, derived from competing models of science communication, that exposure to information on geoengineering would provoke discounting of climate-change risks generally. Contrary to this hypothesis, we found that subjects exposed to information about geoengineering were slightly more concerned about climate change risks than those assigned to a control condition

The e-Business Readiness Composite Indicator for 2003. A Pilot Study

Abstract not availableJRC.G-Institute for the Protection and the Security of the Citizen (Ispra

Probing magnetic fields with multi-frequency polarized synchrotron emission

We investigate the problem of probing the local spatial structure of the magnetic field of the interstellar medium using multi-frequency polarized maps of the synchrotron emission at radio wavelengths. We focus in this paper on the three-dimensional reconstruction of the largest scales of the magnetic field, relying on the internal depolarization (due to differential Faraday rotation) of the emitting medium as a function of electromagnetic frequency. We argue that multi-band spectroscopy in the radio wavelengths, developed in the context of high-redshift extragalactic HI lines, can be a very useful probe of the 3D magnetic field structure of our Galaxy when combined with a Maximum A Posteriori reconstruction technique. When starting from a fair approximation of the magnetic field, we are able to recover the true one by using a linearized version of the corresponding inverse problem. The spectral analysis of this problem allows us to specify the best sampling strategy in electromagnetic frequency and predicts a spatially anisotropic distribution of posterior errors. The reconstruction method is illustrated for reference fields extracted from realistic magneto-hydrodynamical simulations