Conditions for requiring nonlinear thermoelectric transport theory in nanodevices

In this paper, we examine the conditions under which the nonlinear transport theory is inescapable, when a correlated quantum dot is symmetrically coupled to two leads submitted to temperature and voltage biases. By detailed numerical comparisons between nonlinear and linear currents, we show that the claimed nonlinear behavior in a temperature gradient for the electric current is not so genuine, and the linear theory made at the operating temperature $\bar{T}= (T_H+T_C)/2$ is unexpectedly robust. This is demonstrated for the single impurity Anderson model, in different regimes: resonant tunneling, Coulomb blockade and Kondo regimes

Hund and pair-hopping signature in transport properties of degenerate nanoscale devices

We investigate the signature of a complete Coulomb interaction in transport properties of double-orbital nanoscale devices. We analyze the specific effects of Hund exchange and pair hopping terms, calculating in particular stability diagrams. It turns out that a crude model, with partial Coulomb interaction, may lead to a misinterpretation of experiments. In addition, it is shown that spectral weight transfers induced by gate and bias voltages strongly influence charge current. The low temperature regime is also investigated, displaying inelastic cotunneling associated with the exchange term, as well as Kondo conductance enhancement.Comment: 5 pages, 4 figure

Identification of rolling resistance as a shape parameter in sheared granular media

Using contact dynamics simulations, we compare the effect of rolling resistance at the contacts in granular systems composed of disks with the effect of angularity in granular systems composed of regular polygonal particles. In simple shear conditions, we consider four aspects of the mechanical behavior of these systems in the steady state: shear strength, solid fraction, force and fabric anisotropies, and probability distribution of contact forces. Our main finding is that, based on the energy dissipation associated with relative rotation between two particles in contact, the effect of rolling resistance can explicitly be identified with that of the number of sides in a regular polygonal particle. This finding supports the use of rolling resistance as a shape parameter accounting for particle angularity and shows unambiguously that one of the main influencing factors behind the mechanical behavior of granular systems composed of noncircular particles is the partial hindrance of rotations as a result of angular particle shape.Comment: Soumis a Physical Review E; Statistical, Nonlinear, and Soft Matter Physics http://link.aps.org/doi/10.1103/PhysRevE.84.01130

The Politics of Memory: A Study of the Formation and Influence of Public Memory of the Military Regime in Argentina

[This study investigated the influence of various political and non-political factors public memory of the period of military regime rule in Argentina from 1976 through 1983. The sources utilized in the study mainly include scholarly works, in addition to several news articles, poll data, and a series of films concerning the subject. The study found that the development of public memory of this particular political event has been influenced by a complex array of interest groups. Each group utilized a unique set of methods and mediums to convey its preferred account of the period of regime rule. The interest groups include the government of Argentina, the military\u27 of Argentina, and several Argentine civil society and human rights organizations such as the Madres of the Plaza de Mayo and HIJOS, among others. Some of the methods and mediums utilized include filrn, print and broadcast news sources, public demonstration, and other sources of primed literature. The study concludes that though the political entities of the government and the military initially held the most influence over public memory of this time period, changes in technology and information sharing over the years have allowed the general public as represented by civil society and human rights groups to incorporate its perspective into current public memory as well.

The effect of dimensions of knowledge sharing on a variety of strategic mind map of managers and employees

Based on cognitive school of strategic management, the mental (intellectual) map of managers and employees is highly effective on survival and development of their companies. The number of mental maps that managers and employees of a company have on situations and categories (quantity) and the quality (accuracy and precision) of mind maps can be decisive factors in the success of their companies. One of the most important factors affecting the mind map is knowledge sharing. This study seeks to explain the dimensions of this impact. Based on objective, this is a descriptive - explanatory study, while it is an applied one according to the result. It is cross-sectional research based on time, and a surveying according to the methodology. The target population members included the managers and employees of a large industrial complex in the North West of Iran. The sampling method was a stratified randomized approach, and the sample size was calculated using the Cochran formula as 237 subjects. The data were collected by a researcher-made questionnaire containing 36 questions. The results showed that knowledge sharing affects the formation of a strategic map of managers and employees significantly and differently through each of the three categories of organizational factors, personal factors, and knowledge factors. This means that each of these knowledge sharing approaches affects each of the eight mind maps with different quality and quantity. Also, knowledge sharing is not a universal current among all managers and employees; in addition, it is unclear that sharing of knowledge will essentially boost more useful and functional mental maps, and perhaps, it would act otherwise. Therefore, it is necessary to conduct the process of knowledge-sharing to continuously integrate and improve mind maps of decision-takers and decision-makers

Quasistatic rheology, force transmission and fabric properties of a packing of irregular polyhedral particles

By means of contact dynamics simulations, we investigate a dense packing composed of polyhedral particles under quasistatic shearing. The effect of particle shape is analyzed by comparing the polyhedra packing with a packing of similar characteristics except for the spherical shape of the particles. The polyhedra packing shows higher shear stress and dilatancy but similar stress-dilatancy relation compared to the sphere packing. A harmonic approximation of granular fabric is presented in terms of branch vectors (connecting particle centers) and contact force components along and perpendicular to the branch vectors. It is found that the origin of enhanced shear strength of the polyhedra packing lies in its higher force anisotropy with respect to the sphere packing which has a higher fabric anisotropy. Various contact types (face-vertex, face-face, etc) contribute differently to force transmission and fabric anisotropy. In particular, most face-face contacts belong to strong force chains along the major principal stress direction whereas vertex-face contacts are correlated with weak forces and oriented on average along the minor principal stress direction in steady shearing

« La dame Comptabilité », une analogie au service de la vulgarisation comptable : de la circulation sanguine à la santé de l'entreprise

Comment rendre accessible à un public non formé les documents comptables et de gestion ? Cet article analyse un exemple de vulgarisation, datant de 1933, qui repose sur une analogie avec la circulation sanguine. Pour ce faire, le travail de recherche a consisté à établir un état des connaissances comptables diffusées entre 1900 et 1933 pour mettre en perspective le document étudié. Si l'auteur prend des libertés avec l'anatomie, l'analogie apparaît pertinente puisqu'elle permet de faire le lien avec la notion de santé de l'entreprise : santé de l'entreprise sur laquelle jouent les évènements et les choix des dirigeants, apparence de santé grâce à des manipulations comptables. Il semble également que sur cette période que l'analogie ne soit utilisée que dans le cadre de la vulgarisation.Analogie; vulgarisation; histoire de la comptabilité; période 1900-1933; circulation sanguine