Non-Markovian Dynamics of Quantum Discord

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.Comment: 6 pages, 4 figure

On the r−r-stability of spacelike hypersurfaces

In this paper we study the strong stability of spacelike hypersurfaces with constant $r$-th mean curvature in Generalized Robertson-Walker spacetimes of constant sectional curvature. In particular, we treat the case in which the ambient spacetime is the de Sitter space

Elastic Constitutive Laws and Stability Analyses

In this paper, the influence of several elastic constitutive laws upon the stability analyses of plane trusses is discussed. The chosen laws are connected to the engineering strain, Green’s strain and logarithmic strain concepts. A geometrically exact nonlinear formulation for a truss bar element is developed for each of them and the correspondent tangent stiffness matrices are obtained. The stability analyses of some sample plane trusses are performed by finding the conditions when the determinant of their respective global tangent stiffness matrices is found to be zero. The first example is a symmetric two-bar structure and both limit loads and buckling loads are plotted for the full range of possible initial inclination angles of the bars for the three chosen constitutive laws. A similar truss with an extra vertical bar is studied to discuss possible material instability if Green’s strain concept is adopted

Quantum state tomography and quantum logical operations in a three qubits NMR quadrupolar system

In this work, we present an implementation of quantum logic gates and algorithms in a three effective qubits system, represented by a (I = 7/2) NMR quadrupolar nuclei. To implement these protocols we have used the strong modulating pulses (SMP). The various stages of each implementation were verified by quantum state tomography (QST). It is presented here the results for the computational base states, Toffolli logic gates, and Deutsch-Jozsa and Grover algorithms. Also, we discuss the difficulties and advantages of implementing such protocols using the SMP technique in quadrupolar systems.Comment: 24 pages, 8 figure

WAKE CHARACTERIZATION IN ROW ARRAY OF HYDROKINETICS TURBINES

This study aims to obtain wake information, which passes through a linear array of turbines. Is presented a numerical approach to observe what effect can be obtained from a 2.2 meters turbines set. The linear array parameters were based on the Hydro-k project, in which two unconfined in-line rotors were used. The studies were performed by analyzing three variables: mean normalized velocity, turbulence kinetic energy and turbulence intensity. It was noted that the iteration between the rotors alters the flow on the array of turbines increasing the center speed

Utilização de FSH:LH como alternativa para estimular o crescimento folicular na sincronização do estro ovino.

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Dynamic of polycyclic aromatic hydrocarbons in soils treated with biochar.

In recent years the interest in pyrogenic carbon for agricultural use (biochar, i.e. carbonized biomass for agricultural use) has sharply increased. However biochar contain dangerous compounds such as Polycyclic Aromatic Hydrocarbons (PAHs), many of them potentially carcinogenic and mutagenic. They are organic compounds formed from incomplete combustion of organic materials and are persistent pollutants. Therefore, PAHs concentrations and their dynamic must be evaluated in soils amended with biochar. For this, soil samples were collected in three experimental areas in different years (1, 3, 5 or 6) after the application of 0 (control) or 16 Mg ha-1 of biochar. This is the first report of PAHs persistence up to six years in soil treated with biochar. The biochar application increased total PAHs concentrations up to five years after the application, however the levels have always been an order of magnitude lower the limits of prevention established by International Environmental Agencies for soils. Thus, under the evaluated conditions ,the use of biochar was safe concerning PAHs contamination, besides, after six years of the application, the levels found were similar to the control treatment, making it possible to define a safe frequency of application based on the persistence of PAHs in soil

Tender vacancies allocation to the member units of a public research company: a data envelopment analysis approach.

The Brazilian Agricultural Research Corporation is a public research company, comprised of a central management structure and forty-three research centers. Given the recent dismissal of employees, due to retirement or to promoted layoffs, and the expected announcement of a recruitment to replace the staff, it is important to define how these vacancies will be distributed among its member units. This study proposes data envelopment analysis (DEA) models to allocate the vacancies to the company’s research centers, using Zero Sum Gains DEA (ZSG-DEA). We studied both production and performance modeling perspectives. Given the approaches adopted and the variables selected, the ZSG-DEA models generated al- location proposals in which all units are 100% efficient. This is the ideal scenario for a central management: maximum efficiency in the use of its resources