Gas phase thermometry of hot turbulent jets using laser induced phosphorescence

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 OSAThe temperature distributions of heated turbulent jets of air were determined using two dimensional (planar) laser induced phosphorescence. The jets were heated to specific temperature increments, ranging from 300 – 850 K and several Reynolds numbers were investigated at each temperature. The spectral ratio technique was used in conjunction with thermographic phosphors BAM and YAG:Dy, individually. Single shot and time averaged results are presented as two dimensional stacked images of turbulent jets. YAG:Dy did not produce a high enough signal for single shot measurements. The results allowed for a direct comparison between BAM and YAG:Dy, revealing that BAM is more suitable for relatively lower temperature, fast and turbulent regimes and that YAG:Dy is more suited to relatively higher temperature, steady flow situations

Information Spillover, Volatility and the Currency Markets for the Binary Choice Model

We use an impulse response methodology to analyse the effects of U.S. macroeconomic news announcements on the volatilities of three major exchange rates (Euro, Pound Sterling and Yen). Our data consist of 5 minute returns on exchange rates as well as the times of news announcements. In the definition of impulse responses, we allow for different types of news, and consider two categories in the application: those considered positive or negative for the U.S. economy. Using a multivariate GARCH model with exogenous news effects, we find that the initial impact of positive news on the volatility of the Pound is higher than that of the Euro, whereas the persistence of shocks is highest for the Yen. For negative news, we find that an important part of the impact on the Yen and Pound is induced by volatility spillover from the Euro.Information, Volatility, Impulse Response Function, Foreign Exchange

Design and Development of a Vision System Interface for Three Degree of Freedom Agricultural Robot

In this study, a vision system interfaced 3DOF agricultural harvester robot was designed, developed and tested. The robot was actuated by hydraulic power for heavy tasks such as picking and harvesting oil palm FFB. The design was based on the task of that robot, the type of actuators and on the overall size. Attention was given to the stability, portability and kinematic simplicity in relation to the hydraulic actuators. The derivation of the kinematic model was based on the Matrix Algebra for the forward kinematics, and the inverse kinematics problem was based on analytical formulation. The D-H representation was used to carry out the coordinates of the end-effector as the function of the joint angles. The joint angles of the robot were computed as the function of the end-effector coordinates to achieve the inverse kinematic model. A mathematical model that related the joint angles and the actuators length was derived using geometric and trigonometric formulations. A differential system was derived for the manipulator. This differential system represents the dynamic model, which describes relationships between robot motion and forces causing that motion. The Lagrange-Euler formulation with the D-H representation was applied to formulate the differential system. The importance of the derivation of the kinematic model arises in the development of the control strategy. While the derivation of the dynamic model helps in real time simulation. The robot was enhanced by a CCD camera as a vision sensor to recognise red object as a target. Red object was to exemplify the matured oil palm FFB . The recognition process was achieved by using C++ programming language enhanced by MIL functions. An algorithm based on empirical results was developed in order to convert the target coordinates from the image plane (pixel) into the robot plane (cm). The image plane is two-dimensional while the robot plane is three-dimensional. Thus at least one coordinate of the target in the robot plane should be known. An Interface program has been developed using Visual Basics to control and simulate 2D motion of the manipulator

Anticipations effects in endogeneous probability-migration models

We analyze a probability-migration model based on the threshold of average human capital as in H.-J. Chen [1]. The difficult and interesting case is the one where the probability of migration is dependent on current average human capital (the anticipative case). Here, indeterminacy occurs, and one has to study a lot of subcases. In the present article we deeply study new interesting cases and we give a global answer.Human capital, Education, Migration, Indeterminacy, Economic growth, Threshold human capital, Fixed point, Optimistic and pessimistic mechanisms, Conservative mechanism

Corruption Et Croissance Économique Une Approche Économétrique Sur Les Données De l’Algérie

The study of corruption is now a serious subject in the development discourse. Wolfensohn, the former president of the World Bank argues that corruption has become "the largest single inhibitor of equitable economic development." Moreover effects of corruption extended to all countries, Nobel Prize –winning economist Amartya Sen wrote in 2009 that lack of transparency in the global financial system was among the main factors contributing to the financial crisis that began in 2008. The purpose of this paper is to analyze the impact of corruption on economic growth and importance of the transmission channels in Algeria for the period of 2001- 2012. Based on the empirical framework, In our ordinary least squares estimations, we find that, the significant and negative effect of corruption on investment and public spending. The Results indicate also the negative and significant relationship between corruption and economic growth in Algeria

« La combinaison des methodes quantitative et qualitative : Un exemple d’une analyse en Afrique sub-saharienne »

Depuis plusieurs décennies, le rapport entre la croissance démographique et la disponibilité de la terre arable est d’actualité dans de nombreux pays Sud. Plus la population augmente, moins il y a de terre disponible, et plus l’on voit émerger des comportements et se renforcer comme la mobilité ou encore les conflits fonciers. Les individus dans les milieux ruraux cherchent à s’adapter à cette situation de manque de terre et d’insécurité alimentaire. Ainsi, des comportements démographiques, comme la fécondité sont vus comme cause de la raréfaction des surfaces exploitables, et d’autres tels que la migration comme réponse à la pénurie de la terre arable.Est-ce que le niveau de fécondité observé en milieu rural de Madagascar s’explique par les besoins en main-d’oeuvre de l’exploitation agricole familiale ? C’est à cette question que ce travail se propose de répondre. Il s’agit de voir si les ménages ruraux, dans un contexte de pauvreté, mènent conjointement des stratégies démographiques (ici la fécondité) et des stratégies économiques (gestion de l’exploitation agricole). L’analyse est fondée sur des données quantitatives et qualitatives recueillies entre 2003 et 2006 dans une zone rurale des Hautes Terres de Madagascar. Nous tenterons de vérifier les principales théories sur la question terre-fécondité et montrerons l’importance du contexte culturel dans l’analyse socio-démographique.Mots clés : Croissance démographique, Disponibilité en terre, Milieu rural, Madagascar.Codes JEL : N3

Error estimates for scalar conservation laws by a kinetic approach

We use the kinetic approach of Perthame and Tadmor (1991) to calculate the error estimates for general scalar conservation laws governing problems in gas dynamics or fluid mechanics in general. The Kružkov and Kuznetsov techniques are generalized to this method, and an error bound of order ε (where ε is the mean free path) is obtained

Postprivatization Corporate Governance: the Role of Ownership Structure and Investor Protection

We investigate the role of ownership structure and investor protection in postprivatization corporate governance. We find that the government relinquishes control over time, mainly to the benefit of local institutions and foreign investors. We also show that private ownership tends to concentrate over time. In addition to firm-level variables, investor protection, political and social stability explain the cross-firm differences in ownership concentration. We find that the positive effect of ownership concentration on firm performance matters more in countries with weak investor protection and that private domestic ownership leads to higher performance.Corporate governance, privatization, performance

Design of an easy tunable soft sensor for real-time speed and position estimation of PMSM

Volume 4 Issue 2 (February 2016