Effects of vegetation density on flow, mass exchange and sediment transport in lateral cavities

Large-Eddy Simulations (LES) were used to investigate the hydrodynamics and mass transfer between the flow in the main channel and a vegetated lateral cavity. Fourteen vegetation densities (0 to 10.65 %) were tested, revealing two distinct hydrodynamic patterns. For cavities with low vegetation density (a 3.99 %), two gyres in contact with the interface with low velocity were formed, the thickness of the mixing layer did not grow, and the vorticity and turbulence kinetic energy were low inside the cavity. The mass transport presented the same threshold value as the hydrodynamics (a = 3.99 %). For cavities with low vegetation density, a fast mass transfer occurred through the interface between the main channel and cavity and inside the cavity, while the opposite was observed for cavities with high vegetation density. Finally, the modelled hydrodynamics was used to infer possible sediment deposition patterns and flow resistance

Tio2 And Tio2/wo2 Porous Film Electrodes For Application In Solar Energy Conversion

TiO2 and TiO2/WO3 porous films were deposited onto transparent conducting glass electrodes, resulting in uniform films consisted of agglomerated particles with average diameters ranging from 50 to 200 nm; Ti, O and W atoms were homogeneously distributed at the surface of hybrid film. Comparable electrochemical properties were observed in the dark, with small capacitive currents and similar potentials for O2 and H2 evolution reactions in aqueous solution. Under polychromatic irradiation, the hybrid film electrode, molar ratio WO3/TiO 2 = 12%, reveled higher photocurrent and photocatalytic activity for oxidation of phenol and 17-α-ethinylestradiol. The visible light harvesting ability of hybrid film, with band gap energy estimated as 2.3 eV, and the relative position of conduction and valence band edges that inhibits charge recombination, should improve its photocatalytic activity for organic pollutant removal. © 2009 SPIE.7408Fujishima, A., Zhang, X., Tryk, D.A., TiO2 photocatalysis and related surface phenomena (2008) Surf. Sci. Rep., 63, pp. 515-582Chen, X., Mao, S.S., Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications (2007) Chem. Rev., 107, pp. 2891-2959Thompson, T.L., Yates Jr., J.T., Surface science studies of the photoactivation of TiO2-new photochemical processes (2006) Chem. Rev., 106, pp. 4428-4453Shinde, P.S., Patil, P.S., Bhosale, P.N., Brüger, A., Nauer, G., Neumann-Spallart, M., Bhosale, C.H., UVA and solar light assisted photoelectrocatalytic degradation of AO7 dye in water using spray deposited TiO2 films (2008) Appl. Catal. B: Environ., 89, pp. 288-294Oliveira, H.G., Nery, D.C., Longo, C., Effect of applied potential on photocatalytic phenol degradation using nanocrystalline TiO2 electrodes (2009) Appl. Catal. B: Environ., , submittedVeeresh, G.S., Kumar, P., Mehrotra, I., Treatment of phenol and cresols in upflow anaerobic sludge blanket (UASB) process: A review (2005) Water Res., 39, pp. 154-170Addamo, M., Augugliaro, V., Di Paola, A., Garcia-Lopez, E., Loddo, V., Marci, G., Palmisano, L., Removal of drugs in aqueus systems by photoassisted degradation (2005) J. Appl. Electrochem., 35, pp. 765-774Snyder, S.A., Westerhoff, P., Yoon, Y., Sedlak, D.L., Pharmaceuticals, personal care products, and endocrine disrupters in water: Implications for water industry (2003) Environ. Eng. Sci., 20, pp. 449-469Yang, H., Shi, R., Zhang, K., Hu, Y., Tang, A., Li, X., Synthesis of WO3/TiO2 nanocomposites via sol-gel method (2005) J. Alloys Compd., 398, pp. 200-202Yagi, M., Maruyama, S., Sone, K., Nagai, K., Norimatsu, T., Preparation and photoelectrocatalytic activity of a nano-structured WO3 platelet film (2008) J. Solid State Chem, 181, pp. 175-182Ke, D., Liu, H., Peng, T., Liu, X., Dai, K., Preparation and photocatalytic activity of WO3/TiO2 nanocomposite particles (2008) Mater. Lett., 62, pp. 447-450Li, X.Z., Li, F.B., Yang, C.L., Ge, W.K., Photocatalytic activity of WO3-TiO2under visible light irradiation (2001) J. Photochem. Photobiol. A. Chem, 141, pp. 209-217Yang, H., Shi, R., Zhang, K., Hu, Y., Tang, A., Li, X., Synthesis TiO2/WO3 nanocomposites via sol-gel method (2005) J. Alloys Compd., 398, pp. 200-202Muscat, J., Swamy, V., Harrison, N.M., First-principles calculations of the phase stability of TiO2 (2002) Phys. Rev. B, 65, pp. 224121-2241215Bickley, R.I., Gonzalez-Carreno, T., Lees, J.S., Palmisano, L., Tilley, R.J.D., A structural investigation of titanium-dioxide photocatalysts (1991) J. Solid State Chem., 92, pp. 178-190Munoz-Páez, A., Transition metal oxides: Geometric and electronic structures (1994) J. Chem. Educ., 71, pp. 381-388Barton, D.G., Shtein, M., Wilson, R.D., Soled, S.L., Iglesia, E., Structure and electronic properties of solid acids based on tungsten oxide nanostructures (1999) J. Phys. Chem. B, 103, pp. 630-640Higashimoto, S., Ushiroda, Y., Azuma, M., Electrochemically assisted photocatalysis of hybrid WO 3/TiO2 films: Effect of the WO3 structures on charge separation behavior (2008) Top. Catal., 47, pp. 148-154Kaur, S., Singh, V., TiO2 mediated photocatalytic degradation studies of Reactive Red 198 by UV irradiation (2007) J. Haz. Mater., 141, pp. 230-236Li, X.Z., Li, F.B., Yang, C.L., Ge, W.K., Photocatalytic activity of WOx-TiO2under visible light irradiation (2001) J. Photochem. Photobiol. A: Chem., 141, pp. 209-217Li, M.C., Shen, J.N., Photoelectrochemical oxidation behavior of organic substances on TiO 2 thin-film electrodes (2006) J. Solid State Electrochem., 10, pp. 980-986Luo, J., Hepel, M., Photoelectrochemical degradation of naphthol blue black diazo dye on WO3 film electrode (2001) Electrochim. Acta, 46, pp. 2913-2922Waldner, G., Brüger, A., Gaikwad, N.S., Neumann-Spallart, M., WO3 thin films for photoelectrochemical purification of water (2007) Chemosphere, 67, pp. 779-784Lin, C., Wu, C., Onn, Z., Degradation of 4-chlorophenol in TiO2, WO3, SnO2, TiO2/WO3and TiO2/SnO 2 systems (2008) J. Haz. Mater., 154, pp. 1033-1039Rosenfeldt, E.J., Chen, P.J., Kullman, S., Destruction of estrogenic activity in water using UV advanced oxidation (2007) Sci. Total Environ., 377, pp. 105-113Coleman, H.M., Routledge, E.J., Sumpter, J.P., Rapid loss of estrogenicity of steroid estrogens by UVA photolysis and photocatalysis over an immobilised titanium dioxide catalyst (2004) Water Res., 38, pp. 3233-324

Fabrication of mili-scale channels for hemodynamic studies

An anatomical model representing a mili-scale bifurcation of an artery was constructed. A sequential method was developed to obtain a transparent PDMS model from a mold produced by rapid prototyping. The final objective is to manufacture transparent models that allow optical access to measure the velocity profiles of the flow of blood analogues by microparticle image velocimetry (µPIV)

General Relativistic Mean Field Theory for Rotating Nuclei

We formulate a general relativistic mean field theory for rotating nuclei starting from the special relativistic $\sigma - \omega$ model Lagrangian. The tetrad formalism is adopted to generalize the model to the accelerated frame.Comment: 13 pages, REVTeX, no figures, submitted to Phys. Rev. Lett., the word `curved' is replaced by `non-inertial' or `accelerated' in several places to clarify the physical situation interested, some references are added, more detail discussions are given with omitting some redundant sentence

Scalar perturbation spectra from warm inflation

We present a numerical integration of the cosmological scalar perturbation equations in warm inflation. The initial conditions are provided by a discussion of the thermal fluctuations of an inflaton field and thermal radiation using a combination of thermal field theory and thermodynamics. The perturbation equations include the effects of a damping coefficient $\Gamma$ and a thermodynamic potential $V$. We give an analytic expression for the spectral index of scalar fluctuations in terms of a new slow-roll parameter constructed from $\Gamma$. A series of toy models, inspired by spontaneous symmetry breaking and a known form of the damping coefficient, lead to a spectrum with $n_s>1$ on large scales and $n_s<1$ on small scales.Comment: 12 pages, 5 figures, RevTeX 4, revised with extra figure

Estudo do impacto das deficiências de saneamento básico sobre a saúde pública no Brasil no período de 2001 a 2009

O artigo teve como objetivo desenvolver um estudo do impacto sobre a saúde pública das deficiências do saneamento básico no Brasil no período de 2001 a 2009. Os óbitos resultantes de doenças relacionadas ao saneamento básico inadequado corresponderam, em média, a 13.449 mortes por ano, ou seja, cerca de 1,31% do total. A média anual de casos de notificação compulsória devido a doenças relacionadas ao saneamento básico inadequado foi de 466.351 casos, com uma despesa de R$30.428.324,92 em consultas médicas nesse período. Foi identificada também uma média anual de 758.750 internações hospitalares devido a deficiências do saneamento básico, com uma despesa total de R$ 2.111.567.634,61 no período. A despesa total com consultas médicas e internações hospitalares devido a doenças associadas ao saneamento básico consumiu 2,84% dos gastos do Sistema Único de Saúde nesse intervalo de tempo