Thermodynamic stability of nanosized multicomponent bubbles/droplets: The square gradient theory and the capillary approach

Formation of nanosized droplets/bubbles from a metastable bulk phase is connected to many unresolved scientific questions. We analyze the properties and stability of multicomponent droplets and bubbles in the canonical ensemble, and compare with single-component systems. The bubbles/droplets are described on the mesoscopic level by square gradient theory. Furthermore, we compare the results to a capillary model which gives a macroscopic description. Remarkably, the solutions of the square gradient model, representing bubbles and droplets, are accurately reproduced by the capillary model except in the vicinity of the spinodals. The solutions of the square gradient model form closed loops, which shows the inherent symmetry and connected nature of bubbles and droplets. A thermodynamic stability analysis is carried out, where the second variation of the square gradient description is compared to the eigenvalues of the Hessian matrix in the capillary description. The analysis shows that it is impossible to stabilize arbitrarily small bubbles or droplets in closed systems and gives insight into metastable regions close to the minimum bubble/droplet radii. Despite the large difference in complexity, the square gradient and the capillary model predict the same finite threshold sizes and very similar stability limits for bubbles and droplets, both for single-component and two-component systems.

A revision of the revaluation index of Spanish pensions

This article reviews the methodological aspects of the revaluation index of Spanish pensions developed following Law 23/2013 which regulates the sustainability factor and revaluation index of the Social Security pension system. From a gradual breakdown of the elements that make up the revaluation index, an exposition is given of the formal and implementation problems it involves. Finally, its use is illustrated with numerical results.

A revision of the revaluation index of Spanish pensions

This article reviews the methodological aspects of the revaluation index of Spanish pensions developed following Law 23/2013 which regulates the sustainability factor and revaluation index of the Social Security pension system. From a gradual breakdown of the elements that make up the revaluation index, an exposition is given of the formal and implementation problems it involves. Finally, its use is illustrated with numerical results.

Firm dynamics support the importance of the embodied question

This paper contributes to the literature on both embodied technical progress and firm dynamics, by formulating an endogenous growth model where selection and imitation play a fundamental role in helping capital good producers to learn about the productivity of technologies embodied in new plants. By calibrating the model to some key aggregates particularly relevant for the embodied capital literature, among them the growth rate of the relative investment price, the model quantitatively replicates the main facts associated to firm dynamics, such as the entry rate and the tail index of the establishment size distribution. In line with the previous literature, it also predicts a contribution to productivity growth of embodied technical progress and selection of around 60%

Size dependence of refractive index of Si nanoclusters embedded in SiO2

he complex refractive index of SiO2 layers containing Si nanoclusters (Si-nc) has been measured by spectroscopic ellipsometry in the range from 1.5 to 5.0 eV. It has been correlated with the amount of Si excess accurately measured by x-ray photoelectron spectroscopy and the nanocluster size determined by energy-filtered transmission electron microscopy. The Si-nc embedded in SiO2 have been produced by a fourfold Si+ ion implantation, providing uniform Si excess aimed at a reliable ellipsometric modeling. The complex refractive index of the Si-nc phase has been calculated by the application of the Bruggeman effective-medium approximation to the composite media. The characteristic resonances of the refractive index and extinction coefficient of bulk Si vanish out in Si-nc. In agreement with theoretical simulations, a significant reduction of the refractive index of Si-nc is observed, in comparison with bulk and amorphous silicon. The knowledge of the optical properties of these composite layers is crucial for the realization of Si-based waveguides and light-emitting devices.

The effectiveness of market intervention policies to improve diet quality and to reduce the prevalence of obesity in Spain

Our project aims at analyzing the relevance of economic factors (mainly income and other socioeconomic characteristics of Spanish households and market prices) on the prevalence of obesity in Spain and to what extent market intervention prices are effective to reduce obesity and improve the quality of the diet, and under what circumstances. In relation to the existing literature worldwide, this project is the first attempt in Spain trying to get an overall picture on the effectiveness of public policies on both food consumption and the quality of diet, on one hand, and on the prevalence of obesity on the other. The project consists of four main parts. The first part represents a critical review of the literature on the economic approach of dealing with the obesity prevalence problems, diet quality and public intervention policies. Although another important body of obesity literature is dealing with physical exercise but in this paper we will limit our attention to those studies related to food consumption respecting the scope of our study and as there are many published literature review dealing with the literature related to the physical exercise and its effect on obesity prevalence. The second part consists of a Parametric and Non-Parametric Analysis of the Role of Economic Factors on Obesity Prevalence in Spain. The third part is trying to overcome the shortcomings of many diet quality indices that have been developed during last decades, such as the Healthy Eating Index, the Diet Quality Index, the Healthy Diet Indicator, and the Mediterranean Diet Score, through the development of a new obesity specific diet quality index. While the last part of our project concentrates on the assessment of the effectiveness of market intervention policies to improve the healthiness of the Spanish Diet Using the new Exact Affine Stone Index (EASI) Demand System.

Application of the european customer satisfaction index to postal services. Structural equation models versus partial least squars

Customer satisfaction and retention are key issues for organizations in today’s competitive market place. As such, much research and revenue has been invested in developing accurate ways of assessing consumer satisfaction at both the macro (national) and micro (organizational) level, facilitating comparisons in performance both within and between industries. Since the instigation of the national customer satisfaction indices (CSI), partial least squares (PLS) has been used to estimate the CSI models in preference to structural equation models (SEM) because they do not rely on strict assumptions about the data. However, this choice was based upon some misconceptions about the use of SEM’s and does not take into consideration more recent advances in SEM, including estimation methods that are robust to non-normality and missing data. In this paper, both SEM and PLS approaches were compared by evaluating perceptions of the Isle of Man Post Office Products and Customer service using a CSI format. The new robust SEM procedures were found to be advantageous over PLS. Product quality was found to be the only driver of customer satisfaction, while image and satisfaction were the only predictors of loyalty, thus arguing for the specificity of postal services

Improvement of the quality factor of RF integrated inductors by layout optimization

A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when applied to inductors in which the fabrication process includes integration substrate removal. However, it is also applicable to inductors on low-loss substrates. The method optimizes the width of the metal strip for each turn of the inductor coil, leading to a variable strip-width layout. The optimization procedure has been successfully applied to the design of square spiral inductors in a silicon-based multichip-module technology, complemented with silicon micromachining postprocessing. The obtained experimental results corroborate the validity of the proposed method. A Q factor of about 17 have been obtained for a 35-nH inductor at 1.5 GHz, with Q values higher than 40 predicted for a 20-nH inductor working at 3.5 GHz. The latter is up to a 60% better than the best results for a single strip-width inductor working at the same frequency.

Construcción de un índice de calidad ocupacional (ICO) para el análisis de la inserción profesional de los graduados universitarios = Building an employment quality index (EQI) to analyse graduates’ access to the labour market

En este trabajo se propone la construcción de un índice de calidad ocupacional (ICO) a partir de los datos de la Encuesta de Inserción Laboral de los Graduados de las Universidades Catalanas realizada por la Agencia para la Calidad del Sistema Universitario de Catalunya (AQU), que ha de permitir un mejor análisis de la información que proporciona la encuesta y facilitar su comparación con estudios similares. La encuesta se realiza tres años después de la graduación. En este artículo, se utiliza la segunda encuesta realizada el año 2005 entre 11.456 graduados (52,63%) de la promoción 2001 (AQU, 2005, Serra-Ramoneda, 2007). El índice se ha elaborado a partir de los indicadores objetivos ‘tipo y duración del contrato laboral’, ‘retribución económica’, ‘adecuación entre la formación universitaria y el empleo’ a los que se otorga una puntuación ponderada según las respuestas dadas por los graduados. La suma de las puntuaciones se matiza con un coeficiente derivado del indicador subjetivo ‘satisfacción con el trabajo en general’. A partir de la información proporcionada por el índice, se realiza un análisis comparativo del nivel de calidad ocupacional que han logrado los graduados de áreas de conocimiento, ámbitos de trabajo, ramas de actividad y ubicaciones territoriales del empleo diferentes. Los resultados obtenidos permiten observar que entre los graduados catalanes los siguientes hechos son buenos predictores de la calidad de la ocupación: haber estudiado una carrera que no sea de Humanidades, ser un hombre, haber desempeñado durante la carrera un trabajo relacionado con los estudios, estar ocupado en la construcción, en instituciones financieras o en servicios a empresas, haber tenido algún tipo de movilidad por motivos de trabajo, trabajar fuera de Cataluña y hacerlo en empresas grandes, especialmente con más de 500 trabajadores. Finalmente, se presentan algunas reflexiones y propuestas que pueden resultar de interés para la orientación de los estudiantes y la planificación universitaria

Production and carcass quality of ten beef cattle breeds of the southwest of Europe

A sample of about 70 young bulls of each of ten beef cattle breeds reared in their typical production systems has been studied regarding growth and carcass quality traits. Breeds included were Asturiana de los Valles (AV), Asturiana de la Montaña (AM), Avileña-Negra Ibérica (A-NI), Bruna dels Pirineus (BP), Morucha (Mo), Pirenaica (Pi) and Retinta (Re) from Spain, and Aubrac (Au), Gasconne (Ga) and Salers (Sal) from France. There existed large differences between breeds and also within breeds. AV and Pi were the breeds with more muscle and less fat, whereas A-NI, Mo and Re were in the opposite side. BP and AM occupied an intermediate position. This allows to classify the Spanish breeds in three groups: AV and Pi would belong to the group of late maturity, A-NI, Mo and Re, would be early maturing breeds, whereas BP and AM, despite the small size of the last, will be of intermediate maturity. In the French populations, Au was the breed with the highest carcass weight and Ga exhibited the lowest. Sal occupied an intermediate position, showing the longer and thinner thigh. In a wide range of carcass weight, the general relationships among carcass traits have been confirmed. Animals with the better conformation were also the leaner and longer carcasses tended to be lowly associated with a poorer conformation and fatter carcasses. Bone content was clearly opposed to carcass conformation and muscle content and was associated with longer carcasses

Meat quality of ten cattle breeds of the Southwest of Europe

A sample of about 70 young bulls of each of ten beef cattle breeds reared in their typical production systems has been characterised with respect to meat quality traits. Breeds included were Asturiana de los Valles, Asturiana de la Montaña, Avileña-Negra Ibérica, Bruna dels Pirineus, Morucha, Pirenaica and Retinta from Spain, and Aubrac, Gasconne and Salers from France. As was previously showed regarding carcass traits, there exist large differences both between and within breed – systems. In general, rustic breeds tended to present darker and redder meats with higher haematin contents, whereas less precocious and more specialised breeds showed brighter meats with bigger water losses. Protein content was similar, whereas intramuscular fat presented the larger variations both between and within breeds. ICDH content was higher in the more rustic breeds, showing the predominantly oxidative character of their fibres. Texture measurements showed in general large within breed-system variations, the differences between breeds being less evident. Within breed-system, daily gain weight was positively associated with brighter and tender meats. In the range studied, increasing slaughter weight within breed did not have influence on meat quality. Conformation was related to lower water holding capacity and less dry matter and intramuscular fat, as well as to a lower haematin content giving brighter meats. The increase in fatness scores was related to an augment of toughness in meat specialised breeds, although in Avileña-Negra Ibérica breed fatness carcasses were related to more tender meats. Redness parameter a* was positively related to fatter animals and opposed to conformation, the opposite being true for the L* (lightness) parameter. There was a small trend of fatter carcasses to be related to oxidative fibres, whereas the muscular fibres of the more conformed carcasses were more glycolytic. Texture measurements maximum load, maximum stress and toughness were very closely related. Shear force was opposed to tenderness. Losses at cooking were opposed to juiciness, but only in the Spanish breeds. No consistent trends regarding relationships between carcass characteristics and tenderness could be observed. Overall acceptability was primarily related with tenderness and flavour, and later on juiciness.

Positive solutions of nonlinear problems involving the square root of the Laplacian

We consider nonlinear elliptic problems involving a nonlocal operator: the square root of the Laplacian in a bounded domain with zero Dirichlet boundary conditions. For positive solutions to problems with power nonlinearities, we establish existence and regularity results, as well as a priori estimates of Gidas-Spruck type. In addition, among other results, we prove a symmetry theorem of Gidas-Ni-Nirenberg type.

The Brezis-Nirenberg type problem involving the square root of the Laplacian

We establish existence and non-existence results to the Brezis-Nirenberg type problem involving the square root of the Laplacian in a bounded domain with zero Dirichlet boundary condition.

The eta invariant and equivariant index of transversally elliptic operators

We prove a formula for the multiplicities of the index of an equivariant transversally elliptic operator on a G-manifold. The formula is a sum of integrals over blowups of the strata of the group action and also involves eta invariants of associated elliptic operators. Among the applications, we obtain an index formula for basic Dirac operators on Riemannian foliations, a problem that was open for many years.

The eta invariant and equivariant index of transversally elliptic operators

We prove a formula for the multiplicities of the index of an equivariant transversally elliptic operator on a G-manifold. The formula is a sum of integrals over blowups of the strata of the group action and also involves eta invariants of associated elliptic operators. Among the applications, we obtain an index formula for basic Dirac operators on Riemannian foliations, a problem that was open for many years.