Study of the influence of the operational parameters on the photoelectro-Fenton performance of an industrial wastewater treatment prototype using Orange II as a model pollutant

AbstractA two-stage photoelectro-Fenton reactor was built and employed to test its ability to remove colour using Orange II as a model dye compound. A set of four critical operational variables was defined for the reactor under study. In order to quantify their significance on colour removal, a 24 experimental factorial design was used. From the resultant data, and from a variable interaction analysis, a model of the reactor's performance as well as a characteristic set of experimental conditions was obtained. From this information, a triple interaction among current density, resin concentration and pH was statistically significant. Hydraulic retention time was not important. The best treatment among those studied was obtained at pH 3, current density 23.9 mA cm−2, and 3.7 g L−1 of resin concentration, with 96% decolorization. The best results with decolorization higher than 86% were obtained at acidic or slightly acidic pH, and higher levels of current density and resin concentration, or lower level of current density and resin concentration

Sedimentation of a rotating sphere in a power-law fluid

a b s t r a c t We measure the sedimenting velocity of rigid spheres in power-law fluids. By imposing a controlled rotation, we can increase the typical shear rate in the surrounding fluid leading to a decrease of the effective fluid viscosity and, consequently, an increase of the sedimentation speed of the spheres. By fitting our experimental measurements to a power-law dependence of the sedimentation speed on the rotation frequency we are able to predict the values of the consistency and power indices for the test fluids. This setup could thus be used as a rheometer for power-law fluids

Quid: observatorio de medios

El informe está dividido en cuatro apartados: “Derecho a la información y transparencia”, “La televisión mexicana”, “Empresas y prácticas periodísticas” y “Los que se fueron”. En el primero de ellos se presenta un texto que ayuda a entender cuál es el momento en el que se encuentran las propuestas legislativas para regular a los medios y las telecomunicaciones en México, y una evaluación de los primeros cinco años del Instituto de Transparencia e Información Pública de Jalisco. El segundo apartado del informe es ecléctico, pues se compone de artículos que trabajan distintas temáticas de la televisión:la estructura y oferta de la televisión en nuestro país (en particular en la ciudad de Guadalajara), la televisión por cable (enfatizando el caso de Megacable), un recuento de cómo se gestó el Canal 44 y de sus prospectivas en 2011, y los mundiales de futbol. La tercera parte del informe documenta algunas de las situaciones más importantes que se viven en el periodismo local: estos trabajos presentan sistemas en crisis (alta vulnerabilidad de los periodistas mexicanos ante un clima de violencia que lejos de disminuir va en aumento, y la participación, por acción u omisión, del Estado mexicano en la sistemática violación de los derechos de quienes dedican su vida al trabajo periodístico. Los siguientes artículos tratan sobre las transformaciones de las empresas periodísticas, particularmente las del sector de la prensa escrita: la rápida e inexorable desaparición de los suplementos culturales, y una radiografía sobre las formas de producción de algunas secciones internacionales de los periódicos tapatíos. Al final se presentan las semblanzas de José Galindo, Raúl Mora Lomelí, S.J., Tomás Eloy Martínez y Juan Pablo Rosell.ITESO, A.C

Poder de pesca, selectividad y eficiencia de las redes de enmalle para la Sarangola (Microlepidotus brevipinnis Steindachner, 1869) en la costa sur de Jalisco, México

Con el fin de determinar la selectividad, poder de pesca y eficiencia de las redes de enmalle para la sarangola Microlepidotus brevipinnis (Steindachner, 1869) en la zona de Bahía de Navidad, Jalisco, se efectuaron muestreos mensuales de la captura obtenida con redes de 7,62 y 8,89 cm de luz de malla, de abril de 1994 a marzo de 1995. Los resultados indican que la red de 8,89 cm de tamaño de malla captura organismos en promedio 3 cm más grandes y 110 g más pesados que los capturados por la red de 7,62 cm. La red de 7,62 cm obtiene 1,9 veces más organismos por lance y 1,3 veces más biomasa por lance que la obtenida por la red de 8,89. En el análisis de selectividad, se obtuvo una longitud óptima (100% de probabilidad de retención) de 27,7 y 32,2 cm de longitud total para las redes de 7,62 y 8,89 cm de luz de malla, respectivamente. La eficiencia de una red con respecto a la otra cambia en una proporción entre 25 y 39% conforme aumenta la talla de los peces

A Hydrodynamic Instability Is Used to Create Aesthetically Appealing Patterns in Painting

<div><p>Painters often acquire a deep empirical knowledge of the way in which paints and inks behave. Through experimentation and practice, they can control the way in which fluids move and deform to create textures and images. David Alfaro Siqueiros, a recognized Mexican muralist, invented an <i>accidental painting</i> technique to create new and unexpected textures. By pouring layers of paint of different colors on a horizontal surface, the paints infiltrate into each other creating patterns of aesthetic value. In this investigation, we reproduce the technique in a controlled manner. We found that for the correct color combination, the dual viscous layer becomes Rayleigh-Taylor unstable: the density mismatch of the two color paints drives the formation of a spotted pattern. Experiments and a linear instability analysis were conducted to understand the properties of the process. We also argue that this flow configuration can be used to study the linear properties of this instability.</p></div

A conjugate thermo-electric model for a composite medium.

Electrical transmission signals have been used for decades to characterize the internal structure of composite materials. We theoretically analyze the transmission of an electrical signal through a composite material which consists of two phases with different chemical compositions. We assume that the temperature of the biphasic system increases as a result of Joule heating and its electrical resistivity varies linearly with temperature; this last consideration leads to simultaneously study the electrical and thermal effects. We propose a nonlinear conjugate thermo-electric model, which is solved numerically to obtain the current density and temperature profiles for each phase. We study the effect of frequency, resistivities and thermal conductivities on the current density and temperature. We validate the prediction of the model with comparisons with experimental data obtained from rock characterization tests

Dispersion relation of the black/white layer.

<p>Results shown for <i>At</i> = 0.05 and <i>H</i>₁ = 2.0 mm and <i>H</i>₂ = 1.2 mm. The continuous line shows the dispersion relation from considering the confined fluid layer; The dashed line shows the dispersion relation from a triple fluid layer, considering air properties for the upper most layer. The vertical gray line shows the experimental measurements of the mean blob size from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126135#pone.0126135.g005" target="_blank">Fig 5</a>. The vertical dashed lines (blue and red) show the measurements of blob sizes from ‘Collective Suicide’ [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126135#pone.0126135.ref014" target="_blank">14</a>] and ‘The Birth of Fascism’ [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126135#pone.0126135.ref011" target="_blank">11</a>], (respectively). Note that both <i>n</i> and <i>k</i> are shown in dimensionless form, considering, (<i>g</i>²<i>ρ</i>₁/<i>μ</i>₁)^−1/3 and </p><p></p><p></p><p></p><p><mo stretchy="false">(</mo><mi>g</mi></p><p><mi>ρ</mi><mn>1</mn><mn>2</mn></p><mo>/</mo><p><mi>μ</mi><mn>1</mn><mn>2</mn></p><mo stretchy="false">)</mo><p></p><p><mo>−</mo><mn>1</mn><mo>/</mo><mn>3</mn></p><p></p><p></p><p></p> respectively.<p></p