From independent particle towards collective motion in two electron square lattices

The two dimensional crossover from independent particle towards collective motion is studied using 2 spinless fermions interacting via a U/r Coulomb repulsion in a LxL square lattice with periodic boundary conditions and nearest neighbor hopping t. Three regimes characterize the ground state when U/t increases. Firstly, when the fluctuation $\Delta r$ of the spacing r between the two particles is larger than the lattice spacing, there is a scaling length $Lo=\sqrt{8}\pi^2(t/U)$ such that the relative fluctuation $\Delta r/$ is a universal function of the dimensionless ratio L/Lo, up to finite size corrections of order $L^{-2}$. LLo are respectively the limits of the free particle Fermi motion and of the correlated motion of a Wigner molecule. Secondly, when U/t exceeds a threshold U*(L)/t, $\Delta r$ becomes smalller than the lattice spacing, giving rise to a correlated lattice regime where the previous scaling breaks down and analytical expansions in powers of (t/U) become valid. A weak random potential reduces the scaling length and favors the correlated motion.Comment: 8 pages, 11 figures, to be published in EP

The transitioning process: A qualitative case study of international swimming and diving student-athletes competing in the NCAA

Prior studies examining international student-athletes’ transition experiences to life on American colleges campuses have generally focused on outcomes related to their recruiting experience and change adaptation. Few studies included the adjustment process and challenges faced by the individuals. The primary purpose of this case study was to add to the existing literature by expanding on the psychological transition process of international swimming and diving student-athletes experience after joining an American intercollegiate athletics team. Utilizing Bridges (1986) model, the present study employed semi-structured interviews amongst 10 international student-athletes from a large NCAA Division I university. A thematic analysis revealed seven major themes, which were: realization that change was necessary, reflecting on the decision, language barrier, education system, cultural adjustment and valuable lessons,international bond, and words of wisdom. The findings suggested transition is a multi-stage process that occurs throughout student-athletes’ experiences on campus.   Key words: college athletics, international student-athletes, transitioning proces

Calibration and improved prediction of computer models by universal Kriging

This paper addresses the use of experimental data for calibrating a computer model and improving its predictions of the underlying physical system. A global statistical approach is proposed in which the bias between the computer model and the physical system is modeled as a realization of a Gaussian process. The application of classical statistical inference to this statistical model yields a rigorous method for calibrating the computer model and for adding to its predictions a statistical correction based on experimental data. This statistical correction can substantially improve the calibrated computer model for predicting the physical system on new experimental conditions. Furthermore, a quantification of the uncertainty of this prediction is provided. Physical expertise on the calibration parameters can also be taken into account in a Bayesian framework. Finally, the method is applied to the thermal-hydraulic code FLICA 4, in a single phase friction model framework. It allows to improve the predictions of the thermal-hydraulic code FLICA 4 significantly

Linear tubular switched reluctance motor for heart assistance circulatory: Analytical and finite element modeling

A linear tubular switched reluctance motor is presented. This actuator is devoted to be used as a left ventricular assist device (LVAD). In order to avoid thrombosis, this actuator includes pump and valve functions. By using a St. Jude Medical mechanical valve inside the tubular mover, a pulsatile flow is created in the descending aorta. A linear model of a basic pattern of the actuator based on a reluctance network is developed. Then, a two dimensions finite element method analysis is performed in order to check the analytically calculated performances. Relying on these both models, specific requirements for the design of this kind of motor are discussed

A predictive approach for a real-time remote visualization of large meshes

Déjà sur HALRemote access to large meshes is the subject of studies since several years. We propose in this paper a contribution to the problem of remote mesh viewing. We work on triangular meshes. After a study of existing methods of remote viewing, we propose a visualization approach based on a client-server architecture, in which almost all operations are performed on the server. Our approach includes three main steps: a first step of partitioning the original mesh, generating several fragments of the original mesh that can be supported by the supposed smaller Transfer Control Protocol (TCP) window size of the network, a second step called pre-simplification of the mesh partitioned, generating simplified models of fragments at different levels of detail, which aims to accelerate the visualization process when a client(that we also call remote user) requests a visualization of a specific area of interest, the final step involves the actual visualization of an area which interest the client, the latter having the possibility to visualize more accurately the area of interest, and less accurately the areas out of context. In this step, the reconstruction of the object taking into account the connectivity of fragments before simplifying a fragment is necessary.Pestiv-3D projec

Multi-scale morphology of the galaxy distribution

Many statistical methods have been proposed in the last years for analyzing the spatial distribution of galaxies. Very few of them, however, can handle properly the border effects of complex observational sample volumes. In this paper, we first show how to calculate the Minkowski Functionals (MF) taking into account these border effects. Then we present a multiscale extension of the MF which gives us more information about how the galaxies are spatially distributed. A range of examples using Gaussian random fields illustrate the results. Finally we have applied the Multiscale Minkowski Functionals (MMF) to the 2dF Galaxy Redshift Survey data. The MMF clearly indicates an evolution of morphology with scale. We also compare the 2dF real catalog with mock catalogs and found that Lambda-CDM simulations roughly fit the data, except at the finest scale.Comment: 17 pages, 19 figures, accepted for publication in MNRA

The Sun

In today\u27s society, most people do not routinely think of the cooking power of the sun. Oh, on a hot summer day one may joke about cooking an egg on the sidewalk. However, the reusable resource of the sun is often overlooked as a way to reduce energy loads on wood and electricity. Daily cooking with conventional heating such as ovens or stovetops, require long periods of heat, increasing the amount of fuel needed to cook. Solar cooking eliminates the cost of fuel to complete food preparation (or at least reduces the amount of fuel used for cooking). Solar cooking is reported to decrease fuel consumption by 38%. Solar Cooking description and cooking guidelines

Changing Woman and Yeshe Tsogyel: A comparison of Womens Roles in Din4 and Tibetan Tantra Buddhist Traditions\u27

The solace of finding mother provides comfort in most Buddhist societies. The Diné follow the mother in proximity of all life. This abstract considers parallel significance for two mothers of tradition, who lead their respective followers to a life of spreading knowledge and wisdom. Yeshe Tsogyel is significant in spreading the teaching of Tantra Buddhism, and Changing Woman provides the Din4 the importance of reproduction