Effects of non-unity Lewis numbers in diffusion Flames

The purpose of this work is to carry out direct numerícal simulations of diffusion controlled combustión with non-unity Lewis numbers for the reactants and producís, thus accounting for the düferential diífusion effects of the temperature and concentration fields. We use a formulation (Liñán (1991a)) based on combining the conservation equations in a way to elimínate the reaction terms similar to the method used by Burke and Schumann (1928) for unity Lewis numbers. We present calculations for an axisymmetric fuel jet and for a planar, time evolving mixing layer, leaving out the effects of thermal expansión and variations of the transport coefficients due to the heat reisase. Our results show that the front of the fíame sbifts toward the fuel or oxygen sides owing to the effect of the düferential diífusion and that the location of máximum temperature may not coincide with the fíame. The dependence of the distríbution of the reaction products on their Lewis number has been investigated

Dynamic Model and Control of a New Underwater Three-Degree-of-Freedom Tidal Energy Converter

There is currently a growing interest in developing devices that can be used to exploit energy from oceans. In the recent past, the search for oil and gas at ever-greater depths has led to the evolution of devices with which these resources are extracted. These devices range from those that simply rest on the seabed to those that are fully floating and anchored to it. This trend can be considered as the basis needed to understand the future evolution of devices for harnessing depth renewable resources. This paper presents a simple dynamic modeling and a nonlinear multivariable control model-based system for a new three-degree-of-freedom underwater generator with which energy from depth marine currents is harnessed when reference trajectory tracking for the emersion maneuvers needed to carry out maintenance tasks is performed. The goodness of both the model and the proposed controller has been demonstrated through the development of various simulations in the MATLAB-Simulink environment. Additionally, the validation of the control algorithms was carried out by using the dynamic model offered by the simulation environment Orcina OrcaFlex (software for the dynamic analysis for offshore marine systems) through the MATLAB-OrcaFlex interface

The New Political Economy of EU State Aid Policy

Despite its importance and singularity, the EU’s state aid policy has attracted less scholarly attention than other elements of EU competition policy. Introducing the themes addressed by the special issue, this article briefly reviews the development of EU policy and highlights why the control of state aid matters. The Commission’s response to the current economic crisis notably in banking and the car industry is a key concern, but the interests of the special issue go far beyond. They include: the role of the European Commission in the development of EU policy, the politics of state aid, and a clash between models of capitalism. The special issue also examines the impact of EU policy. It investigates how EU state aid decisions affect not only industrial policy at the national level (and therefore at the EU level), but the welfare state and territorial relations within federal member states, the external implications of EU action and the strategies pursued by the Commission to limit any potential disadvantage to European firms, and the conflict between the EU’s expanding legal order and national

The virtual origin as a first-order correction for the far-field description of laminar jets

The far-field velocity and composition fields of a submerged laminar jet are known to approach a self-similar solution corresponding to the flow induced by a point source of momentum and scalar. Previous efforts to improve this far-field description have introduced a virtual origin for the streamwise coordinate to remedy the singular behavior of the self-similar solution near the jet origin. The purpose of this note is to show, by means of a perturbative analysis of the point-source solution, that this virtual origin is in fact the first-order correction to the leading-order description. The perturbative analysis, which uses the ratio x of the streamwise distance to the length of jet development as an asymptotically large quantity, also indicates that the displaced point source provides the description in the far field with small relative errors of order x-3 for the round jet and of order x-10/3 for the plane jet. The values of the virtual origin are obtained by numerical integration of the boundary-layer equations in the region of jet development, giving values that depend on the shape of the jet velocity profile at the exit

Approaching an investigation of multi-dimensional inequality through the lenses of variety in models of capitalism

After a synthetic presentation of the state of poverty and inequality in the world and the contradictions incurred by economic theory in this field after decades of globalization and in the midst of a persisting global crisis, in paragraphs 2. and 3. we outline the rational for our theoretical analysis, underlining two main aspects. First of all, in paragraph 2. we recall the reasons which makes inequality a multidimensional phenomenon, while in paragraph 3. we explore the reasons why the models of capitalism theory is relevant for studying multidimensional inequality. These paragraphs emphasise that inequality is a multidimensional and cumulative phenomenon and it should not be conceived only as the result of the processes of personal and functional distribution of income and wealth, which even by themselves are intrinsically multidimensional. The basic idea is that institutions, the cobweb of relations among them and their interaction with the economic structure define the model of capitalism which characterises a specific country and this, in turn, affects the level and the dynamics of inequality. This approach is consistent with the sociological approach by Rehbein and Souza (2014), based on the analytical framework developed by Pierre Bourdieu. In paragraph 4. we outline the rational for our empirical analysis, applying the notion of institutional complementarity and examining the relationship between institutional complementarity, models of capitalism and inequality. Besides, refining Amable’s analysis (2003), we provide empirical evidence on the relationship between inequality in income distribution and models of capitalism. Additionally, basing on cluster analysis, we identify six different models of capitalism in a sample of OECD countries, provide preliminary evidence on the different level of inequality which characterises each model and suggest that no evidence supports of the idea that a single model of capitalism is taking shape in this sphere in EU. In paragraph 5. we give some hints about issues in search for a new interpretation capable to fasten together the process of increasing inequality, the notion of symbolic violence and the models of capitalism theory. In the last paragraph we focus on conclusions useful for carrying on our research agenda

On the interaction of vortices with mixing layers

We describe the perturbations introduced by two counter-rotating vortices - in a two-dimensional configuration - or by a vortex ring - in an axisymmetric configuration - to the mixing layer between two counterflowing gaseous fuel and air streams of the same density. The analysis is confined to the near stagnation point region, where the strain rate of the unperturbed velocity field, A0, is uniform. We restrict our attention to cases where the typical distance 2r0 between the vortices - or the characteristic vortex ring radius r0 - is large compared to both the thickness, δv, of the vorticity core and the thickness, δm∼(ν/A0)1/2, of the mixing layer. In addition, we consider that the ratio, Γ/ν, of the vortex circulation, Γ, to the kinematic viscosity, ν, is large compared to unity. Then, during the interaction time, A0,-1, the viscous and diffusion effects are confined to the thin vorticity core and the thin mixing layer, which, when seen with the scale r0, appears as a passive interface between the two counterflowing streams when they have the same density. In this case, the analysis provides a simple procedure to describe the displacement and distortion of the interface, as well as the time evolution of the strain rate imposed on the mixing layer, which are needed to calculate the inner structure of the reacting mixing layer as well as the conditions for diffusion flame extinction and edge-flame propagation along the mixing layer. Although in the reacting case variable density effects due to heat release play an important role inside the mixing layer, in this paper the analysis of the inner structure is carried out using the constant density model, which provides good qualitative understanding of the mixing layer response

High-Performance Work Systems and Organizational Performance in Emerging Economies: Evidence from MNEs in Turkey

This study examines the association between the usage of high-performance work systems (HPWS) by subsidiaries of multinational enterprises (MNEs) in Turkey and employee and subsidiary level outcomes. The study is based on a survey of 148 MNE subsidiaries operating in Turkey. The results show that the usage of HPWS has a significant positive impact on employee effectiveness. However, their impact on employee skills and development, and organizational financial performance are far less clear. Our findings highlight the extent to which HWPS need to be adapted to take account of context-specific institutional realities. © 2014 Springer-Verlag Berlin Heidelberg

The effects of market economy and foreign MNE subsidiaries on the convergence and divergence of HRM

This study explores patterns of human resource management (HRM) practices across market economies, and between indigenous firms and foreign MNE subsidiary operations, offering a novel perspective on convergence and divergence. Applying institutional theorizing to improve our understanding of convergence/ divergence as a process and an outcome, data collected from nine countries at three points in time over a decade confirm that convergence and divergence occur to different extents in a non-linear fashion, and vary depending on the area of HRM practice observed. Patterns of adoption and convergence/ divergence are explained through the effect of institutional constraints, which vary between liberal and coordinated market economies, and between indigenous firms and foreign MNE subsidiaries. The study contributes a more graded conceptualization of convergence/ divergence, which reflects the complex dynamic reality of international business

CSR and related terms in SME owner-managers' mental models in six European countries: national context matters

As a contribution to the emerging field of corporate social responsibility (CSR) cognition, this article reports on the findings of an exploratory study that compares SME owner–managers’ mental models with regard to CSR and related concepts across six European countries (Belgium, Italy, Norway, France, UK, Spain). Utilising Repertory Grid Technique, we found that the SME owner–managers’ mental models show a few commonalities as well as a number of differences across the different country samples. We interpret those differences by linking individual cognition to macro-environmental variables, such as language, national traditions and dissemination mechanisms. The results of our exploratory study show that nationality matters but that classifications of countries as found in the comparative capitalism literature do not exactly mirror national differences in CSR cognition and that these classifications need further differentiation. The findings from our study raise questions on the universality of cognition of academic management concepts and warn that promotion of responsible business practice should not rely on the use of unmediated US American management terminology

Efecto catalítico de un electrodo modificado sobre la reacción de oxidación del ácido ascórbico

The electrochemical behavior of ascorbic acid (AA) is of great interest for neurochemical studies, since it is found in high concentrations in the brain tissue, interfering in the electrochemical detection of catecholamines, being AA a good catalyst for their oxidation. In this work, electrochemical parameters have been optimized for the performance of the electrosynthesis of poly (2,5-dimethoxyaniline, PDMA) on platinum (Pt) electrode and Glassy Carbon (GC), as well as for the further incorporation of the Kegging type heteropolyanion(HPA) H4PMo11VO40 on the polymeric matrix. It was found that the systems GC/PDMA/ HPA are stable in H2SO4. Microscopic studies show that PDMA exhibits a uniform porous morphology followed by fibrilar growth which is not significantly affected with incorporation of HPA. The catalytic activity of the systems involved in this study was tested by following the oxidation of AA.Determination of AA in GC/PDMA using Linear sweep voltammetry (LSV), showed linearity within 1.42 and 100 mM with a correlation coefficient of 0.9990, a detection limit of 0.42 mM and quantification limit of 1.42 mM. The system GC/PDMA/HPA showed linearity between 1.13 and 100 mM. a correlation coefficient of 0.9993, detection limit of 0.34 mM and quantification limit of 1.13 mM. By Differential Pulse Voltammetry (DPV), the system GC/PDMA showed linearity between 6.74 and 100 mM with a correlation coefficient of 0.9950, detection limit of 2.02 mM and a quantification limit of 6.74 mM, while the system GC/PDMA/ HPA was linear within 6.40 and 100 mM with a correlation coefficient of 0.9936, detection limit of 1.92 mM and quantification limit of 6.40 mM. These results allow suggesting the use of the modified systems to detect AA at the level of medical drugs.El comportamiento electroquímico del ácido ascórbico es de gran interés en los estudios neuroquímicos por encontrarse en altas concentraciones en el tejido cerebral e interferir en la detección electroquímica de las catecolaminas debido a que cataliza la oxidación de las mismas. En el presente estudio se optimizaron los parámetros electroquímicos para la síntesis de la poli (2,5-dimetoxianilina) (PDMA) sobre electrodos de platino (Pt) y carbón vítreo (CV); así como para la posterior incorporación del heteropolianión (HPA) tipo Keggin H4PMo11VO40 sobre la matriz polimérica. Se encontró que los sistemas CV/PDMA CV/PDMA/HPA son estables en H2SO4. Los estudios de microscopia, demuestran que la PDMA presenta una morfología uniforme y porosa con crecimiento fibrilar, la cual no se ve afectada significativamente con la incorporación del HPA. La actividad catalítica de los sistemas involucrados en este estudio se llevó a cabo utilizando para ello la reacción de oxidación del ácido ascórbico. La determinación del AA en el sistema CV/PDMA porVoltametría de barrido lineal (VL), mostró linealidad entre 1,42 y 100 mM con un coeficiente de correlación de 0,9990, límite de detección de 0,42 mM y límite de cuantificación de 1,42 mM, por su parte el sistema CV/PDMA/HPA presentó linealidad entre 1,13 y 100 mM, coeficiente de correlación de 0.9993, límite de detección 0,34 mM y límite de cuantificación de 1,13 mM. Por voltametría de pulso diferencial (VPD), el sistema CV/PDMA, mostró un intervalo entre 6,74 y 100 mM con coeficiente de correlación de 0,9950, límite de detección de 2,02 mM y límite de cuantificación de 6,74 mM, mientras el sistema CV/PDMA/HPA fue lineal entre 6,40 y 100 mM, coeficiente de correlación de 0,9936, límite de detección 1,92 mM y límite de cuantificación de 6,40. Estos resultados permiten proponer el uso de los sistemas modificados en la determinación de AA a nivel de fármacos