GEOMORFOLOGIA, PAISAGEM, PREVISÃO DE IMPACTOS, ZONEAMENTO E OS RISCOS: ELEMENTOS PARA O PLANEJAMENTO.

Este trabalho aborda procedimentos teóricos e metodológicos envolvendo o tema dos riscos a partir dos geossistemas como interface da geomorfologia aliada aos preceitos de previsão de impactos, assim como a produção de um zoneamento ambiental. O objetivo é identificar o que a temática atual exige de conhecimentos e quais as categorias mais relevantes em diferentes unidades espaciais de análise. Tal trabalho foi feito a partir de levantamento bibliográfico, e operacionalizado para Manaus

Decay Modes of Intersecting Fluxbranes

Just as the single fluxbrane is quantum mechanically unstable to the nucleation of a locally charged spherical brane, so intersecting fluxbranes are unstable to various decay modes. Each individual element of the intersection can decay via the nucleation of a spherical brane, but uncharged spheres can also be nucleated in the region of intersection. For special values of the fluxes, however, intersecting fluxbranes are supersymmetric, and so are expected to be stable. We explicitly consider the instanton describing the decay modes of the two--element intersection (an F5-brane in the string theory context), and show that in dimensions greater than four the action for the decay mode of the supersymmetric intersection diverges. This observation allows us to show that stable intersecting fluxbranes should also exist in type 0A string theory.Comment: 19 pages, 6 figures. References adde

IDENTIFICAÇÃO DAS ÁREAS DE RISCO NA PORÇÃO OESTE DA BACIA HIDROGRÁFICA DO PURAQUEQUARA, MANAUS – AM.

Em Manaus, as áreas de risco vêm crescendo a cada ano, juntamente com a precariedade de infraestrutura, assim os riscos se inserem na cidade, carentes de uma cultura política administrativa e reivindicativa dos moradores, principalmente pela carência habitacional existente (que favorece a autoconstrução e enclaves) Deste modo, este trabalho consistiu na análise das áreas de risco, especificamente a Porção Oeste da Bacia Hidrográfica do Puraquequara (B.H.P.)

Particle Pair Production in Cosmological General Relativity

The Cosmological General Relativity (CGR) of Carmeli, a 5-dimensional (5-D) theory of time, space and velocity, predicts the existence of an acceleration a_0 = c / tau due to the expansion of the universe, where c is the speed of light in vacuum, tau = 1 / h is the Hubble-Carmeli time constant, where h is the Hubble constant at zero distance and no gravity. The Carmeli force on a particle of mass m is F_c = m a_0, a fifth force in nature. In CGR, the effective mass density rho_eff = rho - rho_c, where rho is the matter density and rho_c is the critical mass density which we identify with the vacuum mass density rho_vac = -rho_c. The fields resulting from the weak field solution of the Einstein field equations in 5-D CGR and the Carmeli force are used to hypothesize the production of a pair of particles. The mass of each particle is found to be m = tau c^3 / 4 G, where G is Newton's constant. The vacuum mass density derived from the physics is rho_vac = -rho_c = -3 / (8 pi G tau^2). The cosmic microwave background (CMB) black body radiation at the temperature T_o = 2.72548 K which fills that volume is found to have a relationship to the ionization energy of the Hydrogen atom. Define the radiation energy epsilon_gamma = (1 - g) m c^2 / N_gamma, where (1-g) is the fraction of the initial energy m c^2 which converts to photons, g is a function of the baryon density parameter Omega_b and N_gamma is the total number of photons in the CMB radiation field. We make the connection with the ionization energy of the first quantum level of the Hydrogen atom by the hypothesis epsilon_gamma = [(1 - g) m c^2] / N_gamma = alpha^2 mu c^2 / 2, where alpha is the fine-structure constant and mu = m_p f / (1 + f), where f= m_e / m_p with m_e the electron mass and m_p the proton mass.Comment: 14 pages, 0 figures. The final publication is available at springerlink.co

Efeitos de ethephon e uréia na maturação de frutos e abscisão foliar do cafeeiro (Coffea arábica L.)

A field experiment was carried out to investigate the effects of ethephon and urea on ripening of fruits and leaf abscission of coffee plant. Ethephon (2-chloroethane phosphonic acid) sprays were applied to green Coffea arábica berries 26 days before counting date in concentrations of 0.5 and 0.25 ml/1 from Ethrel (240 a.i./l). The chemical accelerated the onset of fruit ripening at both concentrations. The efficacy of ethephon was increased adding urea. Ethephon 0.5 ml/1 promoted abscission of leaves and low concentration reduced shedding of leaves. The treatments did not affect the growth and production on the next harvest.Como o ethephon pode melhorar a uniformidade na maturação dos frutos e uréia pode aumentar a eficácia do regulador vegetal, estes compostos foram utilizados no estudo da maturação e abscisão foliar em cafeeiro. E-thephon (ácido 2-cloroetilfosfônico) foi pulverizado em Coffea arábica cv. CatuaT Vermelho com frutos verdes, nas dosagens de 0,5 e 0,25 ml/l de Ethrel (240g i.a./l). 0 regulador vegetal acelerou a maturação dos frutos em ambas dosagens e adicionando-se uréia 2%, conforme determinações realizadas 26 dias após os tratamentos. A eficiência do ethephon foi incrementada com adição de uréia. Ethephon 0,5 ml/l provocou absci são foi iar, sendo que a dosagem de 0,25 ml/1 reduziu a queda das folhas do cafeeiro. Os tratamentos não afetaram o desenvolvimento dos ramos e a frutificação na safra seguinte

CARACTERIZAÇÃO MORFOPEDOLÓGICA E CAPACIDADE DE USO DA TERRA NO MUNICÍPIO DE MINAÇU-GO.

O objetivo deste estudo é apresentar uma avaliação da capacidade de uso da terra e da suscetibilidade a erosão por compartimentos morfopedológicos. O estudo foi aplicado no município de Minaçu-GO e os resultados apresentam três grupos de compartimentos: Um grupo onde a suscetibilidade erosão é alta mas o uso é compatível; outro em que a suscetibilidade é moderada e com problemas simples de conservação e um terceiro grupo com alta suscetibilidade, com problemas complexos de conservação

Fuzzy Rings in D6-Branes and Magnetic Field Background

We use the Myers T-dual nonabelin Born-Infeld action to find some new nontrivial solutions for the branes in the background of D6-branes and Melvin magnetic tube field. In the D6-Branes background we can find both of the fuzzy sphere and fuzzy ring solutions, which are formed by the gravitational dielectric effect. We see that the fuzzy ring solution has less energy then that of the fuzzy sphere. Therefore the fuzzy sphere will decay to the fuzzy ring configuration. In the Melvin magnetic tube field background there does not exist fuzzy sphere while the fuzzy ring configuration may be formed by the magnetic dielectric effect. The new solution shows that $D_0$ propagating in the D6-branes and magnetic tube field background may expand into a rotating fuzzy ring. We also use the Dirac-Born-Infeld action to construct the ring configuration from the D-branes.Comment: Latex, 15 pages, detailed comments in section 2, typos correcte

PU tensile tests: conventional and digital image correlation analysis

Polyurethane (PU) is a polymer, used as coating, paint, foam, adhesive, and even in biomedical devices. To furthermore expand its applications, it can be combined with additives such as Calcium Carbonate (CaCO3), an inexpensive material, widely available in nature, or with fibers, such as glass fibers explored in several sectors, likewise the aerospace and automobile industries. To determine the mechanical properties of these materials, the tensile test is the most used due to its great ease of application and flexibility. However, conventional processes, such as the use of strain gauges or crosshead displacement data, may not provide detailed information about the strain field, or cannot be able to evaluate the Poisson's ratio and the true stresses for the entire stressstrain curve. Thus, digital image correlation (DIC) methods are a promising alternative, consisting of strain field measurement without contact with the surface of the structure. In this context, this study carried out the tensile characterization of two main polyurethane samples: one petrochemical, distributed by Sika (R), reinforced with type E glass fiber: and the other, natural, manufactured by Kehl (R) from castor oils, and combined with CaCO3 particles. During the tests, DIC was applied to evaluate the Poisson's ratio and, subsequently, Scanning Electron Microscopy (SEM) analyses were performed, revealing a higher number of bubbles on Sika's polymer, which contributes to the reduction of the maximum supported stresses, since these pores, with dimensions of up to 25 hm, were regions where the cracks started and headed the breakage. Poisson's ratios were all around 0.4 and the highest tensile strength values were obtained from E-glass reinforced samples (TS015), around 117.24 +/- 13.20MPa. CaCO3 particles also acted as reinforced, increasing maximum stress reached from 20MPa to values between 29 and 37MPa.This research was partially funded through the base funding from the following research units: UIDB/00690/2020 (CIMO).info:eu-repo/semantics/publishedVersio

Vacuum effects in an asymptotically uniformly accelerated frame with a constant magnetic field

In the present article we solve the Dirac-Pauli and Klein Gordon equations in an asymptotically uniformly accelerated frame when a constant magnetic field is present. We compute, via the Bogoliubov coefficients, the density of scalar and spin 1/2 particles created. We discuss the role played by the magnetic field and the thermal character of the spectrum.Comment: 17 pages. RevTe