Wastewater Disinfection in Enclosed Recirculation Systems with Electromagnetic Waves

Finding the most cost-effective and environmental friendly way to treat and disinfect wastewater has been raising concerns around the world. Failure in performing disinfection of wastewater before returning it to the environment could have terrible consequences to human health and the ecosystem. The risks associated to continue with current practices have led to the creation of stringent regulations. In this research the HYDROPATH technology is tested while attaching a HydroFlow 60i unit to a reactor that works as a closed recirculation system. To determine the feasibility of the HydroFlow 60i unit as an alternative method to chlorine, the EPA method 1306 is used being Escherichia coli the unit of quantification. After performing several experiments modifying parameters such as conductivity and detention time, it was concluded that the HydroFlow 60i unit by itself would not able to replace current disinfection technologies, to meet EPA standards of E. coli removal

Hubble Diagram of Gamma-Rays Bursts calibrated with Gurzadyan-Xue Cosmology

Gamma-ray bursts (GRBs) being the most luminous among known cosmic objects carry an essential potential for cosmological studies if properly used as standard candles. In this paper we test with GRBs the cosmological predictions of the Gurzadyan-Xue (GX) model of dark energy, a novel theory that predicts, without any free parameters, the current vacuum fluctuation energy density close to the value inferred from the SNIa observations. We also compare the GX results with those predicted by the concordance scenario $\Lambda$-CDM. According to the statistical approach by Schaefer (2007), the use of several empirical relations obtained from GRBs observables, after a consistent calibration for a specific model, enables one to probe current cosmological models. Based on this recently introduced method, we use the 69 GRBs sample collected by Schaefer (2007); and the most recently released SWIFT satellite data (Sakamoto et al. 2007) together with the 41 GRBs sample collected by Rizzuto et al. (2007), which has the more firmly determined redshifts. Both data samples span a distance scale up to redshift about 7. We show that the GX models are compatible with the Hubble diagram of the Schaefer (2007) 69 GRBs sample. Such adjustment is almost identical to the one for the concordance $\Lambda$-CDM.Comment: 9 pages, 17 figures, 11 tables; Astr. & Astrophys. (in press

Revealing the Structure of an Accretion Disk Through Energy Dependent X-ray Microlensing

We present results from monitoring observations of the gravitationally lensed quasar RX J1131-1231 performed with the Chandra X-ray Observatory. The X-ray observations were planned with relatively long exposures that allowed a search for energy-dependent microlensing in the soft (0.2-2 keV) and hard (2-10 keV) light curves of the images of RX J1131-1231. We detect significant microlensing in the X-ray light-curves of images A and D, and energy-dependent microlensing of image D. The magnification of the soft band appears to be larger than that in the hard band by a factor of ~ 1.3 when image D becomes more magnified. This can be explained by the difference between a compact, softer-spectrum corona that is producing a more extended, harder spectrum reflection component off the disk. This is supported by the evolution of the fluorescent iron line in image D over three consecutive time-averaged phases of the light curve. In the first period, a Fe line at E = 6.36(-0.16,+0.13) keV is detected (at > 99% confidence). In the second period, two Fe lines are detected, one at E = 5.47(-0.08,+0.06) keV (detected at > 99% confidence) and another at E = 6.02(-0.07,+0.09) keV (marginally detected at > 90% confidence), and in the third period, a broadened Fe line at 6.42(-0.15,+0.19) keV is detected (at > 99% confidence). This evolution of the Fe line profile during the microlensing event is consistent with the line distortion expected when a caustic passes over the inner disk where the shape of the fluorescent Fe line is distorted by General Relativistic and Doppler effects.Comment: 20 pages, includes 10 figures, submitted to Ap

Aprendiendo a estudiar las clases en el club de apoyo matemático del Huila.

Tradicionalmente ha sido el interés de muchos investigadores conocer las causas de los problemas relacionados con la enseñanza y el aprendizaje de la matemática, y el bajo rendimiento de los estudiantes en esta área; entre las principales se encuentran: los problemas en la formación de los profesores, la desmotivación y falta de interés hacia la matemática, la falta de recursos, la escasa relación entre lo que se enseña y los resultados recientes de investigación, los inconvenientes laborales de los docentes y los problemas socioculturales de los aprendientes, viendo esta situación nos tomamos en la tarea de investigar y poder ayudar con este problema implementando un modelo de clases diferente, usando el modelo de los japoneses, ellos usan tres pasos muy importantes que es la planificación de la clase, la implementación y lo más importante la evaluación, ya que esta nos indica si fue un éxito la clase

Characterizing Cautious Choice

The class of maximin actions in general decision problems is characterized.Maximin actions;Decision problems

A Consistent Picture Emerges: A Compact X-ray Continuum Emission Region in the Gravitationally Lensed Quasar SDSS J0924+0219

We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089A) Hubble Space Telescope data, and high-cadence R-band (rest-frame 2770A) monitoring spanning eleven years. Our joint analysis provides robust constraints on the extent of the X-ray continuum emission region and the projected area of the accretion disk. The best-fit half-light radius of the soft X-ray continuum emission region is between 5x10^13 and 10^15 cm, and we find an upper limit of 10^15 cm for the hard X-rays. The best-fit soft-band size is about 13 times smaller than the optical size, and roughly 7 GM_BH/c^2 for a 2.8x10^8 M_sol black hole, similar to the results for other systems. We find that the UV emitting region falls in between the optical and X-ray emitting regions at 10^14 cm < r_1/2,UV < 3x10^15 cm. Finally, the optical size is significantly larger, by 1.5*sigma, than the theoretical thin-disk estimate based on the observed, magnification-corrected I-band flux, suggesting a shallower temperature profile than expected for a standard disk.Comment: Replaced with accepted version to Ap

Removing black-hole singularities with nonlinear electrodynamics

We propose a way to remove black hole singularities by using a particular nonlinear electrodynamics Lagrangian that has been recently used in various astrophysics and cosmological frameworks. In particular, we adapt the cosmological analysis discussed in a previous work to the black hole physics. Such analysis will be improved by applying the Oppenheimer-Volkoff equation to the black hole case. At the end, fixed the radius of the star, the final density depends only on the introduced quintessential density term $\rho_{\gamma}$ and on the mass.Comment: In this last updated version we correct two typos which were present in Eqs. (21) and (22) in the version of this letter which has been published in Mod. Phys. Lett. A 25, 2423-2429 (2010). In the present version, both of Eqs. (21) and (22) are dimensionally and analytically correc

Endófitos fúngicos relacionados con la maduración natural y compuestos aromáticos en frutos de especies de la orquídea del género Vanilla

The biotic interaction between plants and endophytic fungi strengthens the adaptive capacity of the hosts against environmental disturbances, and confers nutrition and protection benefits to the associated microorganisms. Studies associated with endophytic fungi report their presence in the greatest diversity of existing plants. In hosts such as Cannabis, the interaction with endophytic fungi favors the production of secondary metabolites and phytohormones that participate in obtaining organoleptic properties such as flavors and aromas. However, the research carried out in the Vanilla genus is scarce, making it difficult to understand the functions that these microorganisms can perform for the benefit of the host. In relation to Vanilla, the fruits of species within the aromatic clade are distinguished by the presence of aromatic compounds, which increase their content during ripening. Some studies have shown that in the fruits of this orchid there are endophytic fungi possibly associated with the ripening process that is accelerated by curing, but few of these studies have evaluated the activity of these fungi related to the natural ripening of the fruit. In this review, scientific literature related to the knowledge of fungal endophyte communities and their possible contribution to the ripening and production of aromatic compounds in vanilla fruits is compiled. Research opportunities are identified to develop future studies on the role of fungal microorganisms in obtaining metabolites and aromatic precursors from the fruits of Vanilla species, both in wild conditions and in commercial crops.La interacción biótica entre plantas y hongos endófitos fortalece la capacidad adaptativa de los hospederos frente a perturbaciones del ambiente, y confiere a los microorganismos asociados beneficios de nutrición y protección. Estudios asociados a hongos endófitos reportan su presencia en la mayor diversidad de plantas existentes. En diferentes plantas hospederas, &nbsp;la interacción con hongos endófitos favorece la producción de metabolitos secundarios y fitohormonas que participan en la obtención de propiedades organolépticas como los sabores y los aromas. Sin embargo, las investigaciones desarrolladas en el género Vanilla son escasas, dificultando el entendimiento de las funciones que pueden desempeñar estos microorganismos en beneficio del hospedero. Con relación a Vanilla, los frutos de especies dentro del clado aromático se distinguen por la presencia de compuestos aromáticos, que aumentan su contenido durante la maduración. Algunos estudios, han demostrado que en los frutos de esta orquídea existen hongos endófitos posiblemente asociados al proceso de maduración que se acelera mediante el curado, pero pocos de estos estudios, han evaluado la actividad de dichos hongos relacionados con la maduración del fruto de forma natural. En esta revisión se recopila literatura científica relacionada con el conocimiento de las comunidades de endófitos fúngicos y su posible aporte en la maduración y producción de compuestos aromáticos en los frutos de vainilla. Se identifican oportunidades de investigación para desarrollar futuros estudios sobre el papel de los microorganismos fungosos para la obtención de metabolitos y precursores aromáticos de los frutos en especies de Vanilla, tanto en condiciones silvestres como en cultivos comerciales