Café & saúde humana.

Saúde e fome no Brasil; O café ao longo dos tempos; A cafeína do café; O café não contém só cafeína; Depressão, tabagismo, alcoolismo, consumo de drogas e suicídio; O café pode ajudar na prevenção da depressão e suas conseqüências; Recomendações sobre o uso do café.bitstream/item/32759/1/Cafe-e-saude-humana.pd

Deflection hardening of sustainable fiber–cement composites

In the present study sisal fiber–cement composites reinforced with 4% and 6% of short fibers were developed and their physical–mechanical behavior was characterized. To ensure the composite sustainability and durability, the ordinary Portland cement matrix was modified by adding fly ash and metakaolin, and the natural aggregate was substituted by 10% and 20% of recycled concrete aggregate. Flat sheets were cast in a self-compacted cement matrix and bending tests were performed to determine the first crack, postpeak strength and toughness of the composites. Cyclic flexural tests were carried out to determine the stiffness variation of composite due to cracking formation and propagation. It can be seen that the reinforcement provided by short sisal fibers for recycled cement matrices guaranteed a composite with multiple cracking and an increase of strength after the first crack. Reduction of stiffness and increase the damping capacity of composite are verified with progressive cracking.CAPES (PVE Program: Project 047/2012) and CNPqBrazilian agency FAPESBBrazilian agency CAPES through the PVE Progra

Magnetic phases evolution in the LaMn1-xFexO3+y system

We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn-Teller distortion, thus favoring a ferromagnetic (FM) superexchange (SE) interaction between Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82% of the usual Mn^{3+} ions, with possible double exchange interaction between them. The Fe doping in this system is known to produce only stable Fe^{3+} ions. We find an evolution from a fairly strong FM phase with a Curie temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2 < x < 0.7. A model based on the expected exchange interaction among the various magnetic-ion types, accounts very well for the saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure

Bound - states for truncated Coulomb potentials

The pseudoperturbative shifted - $l$ expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge

Exact solution for the energy density inside a one-dimensional non-static cavity with an arbitrary initial field state

We study the exact solution for the energy density of a real massless scalar field in a two-dimensional spacetime, inside a non-static cavity with an arbitrary initial field state, taking into account the Neumann and Dirichlet boundary conditions. This work generalizes the exact solution proposed by Cole and Schieve in the context of the Dirichlet boundary condition and vacuum as the initial state. We investigate diagonal states, examining the vacuum and thermal field as particular cases. We also study non-diagonal initial field states, taking as examples the coherent and Schrodinger cat states.Comment: 10 pages, 8 figure

Temperature Evolution Law of Imperfect Relativistic Fluids

The first-order general relativistic theory of a generic dissipative (heat-conducting, viscous, particle-creating) fluid is rediscussed from a unified covariant frame-independent point of view. By generalizing some previous works in the literature, we derive a formula for the temperature variation rate, which is valid both in Eckart's (particle) and in the Landau-Lifshitz (energy) frames. Particular attention is paid to the case of gravitational particle creation and its possible cross-effect with the bulk viscosity mechanism.Comment: 14 pages, no figure, revte

Efeito de bioestimulantes sobre as características de produção de videiras Thompson Seedless.

Com o objetivo de avaliar o efeito preliminar de bioestimulantes comerciais sobre as características de produção da videira, foi conduzido um experimento de campo com a cultivar Thompson Seedless, enxertada sobre o porta-enxerto ?Harmony?. Os tratamentos foram constituídos de quatro bioestimulantes, aplicados em três doses, correspondendo a um fatorial 4x3, disposto em blocos casualizados com quatro repetições. No período de pleno florescimento foram coletadas amostras de folhas completas para determinação dos teores totais de nutrientes. Por ocasião da colheita foram avaliadas a produção e algumas características biométricas dos cachos. Houve efeito dos bioestimulantes sobre as concentrações foliares de nitrogênio e potássio e das doses de bioestimulantes sobre os teores de cálcio no período de florescimento. Nenhum dos fatores em estudo, bioestimulantes ou doses, proporcionou aumento da produção, nem sobre a maior parte das características biométricas dos cachos. Esta avaliação preliminar não permitiu observar nenhum efeito robusto dos bioestimulantes sobre as características de produção da videira

Evaluation of Water Quality for Water Bathing Conditions on Querer Beach in the Municipality of Santa Rosa, Tocantins

The water is an indispensable natural resource for life, economic development, and the conservation and maintenance of ecosystem services. It is known that the quantity and quality of water available for consumption is decreasing considerably and the increasing scarcity of this resource may be associated with factors such as the irregular distribution of water, waste and irrational use of it, socioeconomic and environmental problems, pollution of resources inadequate disposal of sewage, lack of basic sanitation and treatment of sewage, among others. In this way, the environmental problems have gained relevant space in the current discussions due to their importance, making the debates of these questions in the society necessary. Because of the anthropic activities that have been developed in a disorderly way and without planning, it reflects drastically in the environmental degradation, especially in this case, in the quality of the waters, which compromises this natural resource, whatever the purpose of its use. Thus, the objective of this work is to evaluate the water quality of Querer Beach in Santa Rosa-TO, promoting a water bathing condition study. Therefore, to investigate the effects of anthropogenic interferences on water quality, the water quality was evaluated by means of monitoring. The analyzes of the bathing conditions, show the percentages obtained for the situations in which the beach is classified as suitable for bathing, the investigations followed the criteria established by the CONAMA resolution n&ordm; 274/00. The water quality at a specific point of the beach was evaluated and monitored for a determined period of six weeks, and the microbiological indicator of water quality according to the Collilert technique according to the methodology described by Standard Methods was used as a parameter. In this way, it was possible to verify the tolerances of the Brazilian parameters for the water bathing conditions indicators of Querer Beach

Constraints on Cold Dark Matter Accelerating Cosmologies and Cluster Formation

We discuss the properties of homogeneous and isotropic flat cosmologies in which the present accelerating stage is powered only by the gravitationally induced creation of cold dark matter (CCDM) particles ($\Omega_{m}=1$). For some matter creation rates proposed in the literature, we show that the main cosmological functions such as the scale factor of the universe, the Hubble expansion rate, the growth factor and the cluster formation rate are analytically defined. The best CCDM scenario has only one free parameter and our joint analysis involving BAO + CMB + SNe Ia data yields ${\tilde{\Omega}}_{m}= 0.28\pm 0.01$ ($1\sigma$) where $\tilde{{\Omega}}_{m}$ is the observed matter density parameter. In particular, this implies that the model has no dark energy but the part of the matter that is effectively clustering is in good agreement with the latest determinations from large scale structure. The growth of perturbation and the formation of galaxy clusters in such scenarios are also investigated. Despite the fact that both scenarios may share the same Hubble expansion, we find that matter creation cosmologies predict stronger small scale dynamics which implies a faster growth rate of perturbations with respect to the usual $\Lambda$CDM cosmology. Such results point to the possibility of a crucial observational test confronting CCDM with $\Lambda$CDM scenarios trough a more detailed analysis involving CMB, weak lensing, as well as the large scale structure.Comment: 12 pages, 3 figures, Accepted for publication by Physical Rev.