Low temperature treatment of municipal sewage in anaerobic fluidized bed reactors

The anaerobic fluidized bed reactor (AFBR) appears to be most promising for the treatment of low strength wastes, such as municipal sewage, at low temperature, since the process is able to maintain a large mass of active microorganisms and provides effective removal of TSS. The study is divided in three parts. The objective of the first part is to characterize the effect of decreasing temperature on the performance of two mature AFBR reactors. The second part presents the data from 220 days of operation at 10°C; and in the third part two start-ups, with and without inoculum at 15°C, are evaluated. A gradual temperature decrease from 20 to 5°C, allowing the microorganisms to acclimate to the new lower temperature, did not have a great effect on effluent quality. However a great accumulation of TSS was observed in the top of the fluidized bed. At 10°C, and a hydraulic retention time of 1.5 h, 70% of T_COD removal was achieved. It is possible to start-up the AFBR at 15°C without inoculation; however, at least 4 months is required to get good quality effluents.     

Strict regulation of c-Raf kinase levels is required for early organogenesis of the vertebrate inner ear

Regulation of organogenesis involves a dynamic balance of the mechanisms regulating cell division, differentiation and death. Here we have investigated the pattern of expression of c-Raf kinase in the inner ear during early developmental stages and the consequences of manipulating c-Raf levels by misexpression of c-raf viral vectors in organotypic cultures of otic vesicle explants. We found that otic vesicles expressed c-Raf and its level remained constant during embryonic days 2 and 3 (E2-E3). c-Raf activity was increased in response to insulin like growth factor-I (IGF-I) and the activation by IGF-I of the c-Raf kinase pathway was a requirement to turn on cell proliferation in the otic vesicle. Overexpression of c-raf in E2.5 explants increased the proliferative response to low serum and IGF-I and blocked differentiation induced by retinoic acid. The increase in c-Raf levels also prevented nerve growth factor (NGF)-dependent induction of programmed cell death. Consistent with these results, the expression of a dominant negative c-Raf mutant potentiated retinoic acid action and decreased the rate of cell proliferation. We conclude that a strict control of c-Raf levels is essential for the co-ordination of the biological processes that operate simultaneously during early inner ear development.     

Life cycle assessment of a multi-megawatt wind turbine

At the present moment in time, renewable energy sources have achieved great significance for modern day society. The main reason for this boom is the need to use alternative sources of energy to fossil fuels which are free of CO₂ emissions and contamination. Among the current renewable energy sources, the growth of wind farms has been spectacular. Wind power uses the kinetic energy of the wind to produce a clean form of energy without producing contamination or emissions. The problem it raises is that of quantifying to what extent it is a totally clean form of energy. In this sense we have to consider not only the emissions produced while they are in operation, but also the contamination and environmental impact resulting from their manufacture and the future dismantling of the turbines when they come to the end of their working life. The aim of this study is to analyse the real impact that this technology has if we consider the whole life cycle. The application of the ISO 14040 standard [ISO. ISO 14040. Environmental management – life cycle assessment – principles and framework. Geneva, Switzerland: International Standard Organization; 1998.] allows us to make an LCA study quantifying the overall impact of a wind turbine and each of its components.Applying this methodology, the wind turbine is analysed during all the phases of its life cycle, from cradle to grave, with regard to the manufacture of its key components (through the incorporation of cut-off criteria), transport to the wind farm, subsequent installation, start-up, maintenance and final dismantling and stripping down into waste materials and their treatment.     

Time-temperature prediction curves of foodstuffs by means of the z-transfer function method

An application of the z-transfer function method to predict temperature-time history of foodstuffs during chilling and cold storage is presented. This application is based on obtaining the temperature z-transfer function's coefficients by means of an experimental method. These coefficients are used to predict the temperature-time history of an homogeneous body and the results are compared with analytical and numerical solutions. This method is very useful when the geometry and/or boundary conditions are such that analytical or numerical solutions are difficult to obtain.     

Nonlinear eddy viscosity modeling and experimental study of jet spreading rates

Indoor airflow pattern is strongly influenced by turbulent shear and turbulent normal stresses that are responsible for entrainment effects and turbulence‐driven secondary motion. Therefore, an accurate prediction of room airflows requires reliable modeling of these turbulent quantities. The most widely used turbulence models include RANS‐based models that provide quick solutions but are known to fail in turbulent free shear and wall‐affected flows. In order to cope with this deficiency, this study presents a nonlinear k‐ε turbulence model and evaluates it along with linear k‐ε models for an indoor isothermal linear diffuser jet flow measured in two model rooms using PIV. The results show that the flow contains a free jet near the inlet region and a wall‐affected region downstream where the jet is pushed toward the ceiling by entrainment through the well‐known Coanda effect. The CFD results show that an accurate prediction of the entrainment process is very important and that the nonlinear eddy viscosity model is able to predict the turbulence‐driven secondary motions. Furthermore, turbulence models that are calibrated for high Reynolds free shear layer flows were not able to reproduce the measured velocity distributions, and it is suggested that the model constants of turbulence models should be adjusted before they are used for room airflow simulations.     

Synthesis of cationic flocculants by the inverse microemulsion copolymerization of acrylamide with 60% 2‐acryloxyethyltrimethyl ammonium chloride in the monomer feed. II. Influence of the formulation composition,hydrophilic‐lipophilic balance,starting polymerization temperature,and reaction time

Acrylamide/2‐acryloxyethyltrimethylammonium chloride copolymers in inverse microemulsions, with 60% 2‐acryloxyethyltrimethyl ammonium chloride in the monomer feed and a concentration of active matter of 30% (w/w) as flocculants, were obtained by inverse microemulsion copolymerization. Inverse microemulsion formulations of comonomers, interesting from both technical and economical viewpoints, were polymerized by semicontinuous free‐radical copolymerization with sodium disulfite as the initiator. The influence of the formulation composition, hydrophilic‐lipophilic balance (HLB), starting polymerization temperature, and reaction time on the polymerization and final properties of the products as flocculants was studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:186–197, 2007     

Identification of the origin of commercial enological tannins by the analysis of monosaccharides and polyalcohols

The monosaccharide and polyalcohol composition of 28-samples of different commercial tannins, including oak wood, grape seed and skin, plant gall, chestnut, quebracho and gambier, has been evaluated by gas chromatography–mass spectrometry after derivatization into their trimethylsilyl ethers. Quercitol was found to be characteristic of oak tannins, whereas gall plant tannins could be differentiated by their content of pinitol. Myo-inositol and arabitol were detected in tannins from quebracho. These polyalcohols, together with muco-inositol and chiro-inositol, were found in tannins from chestnut while bornesitol was found to be characteristic of tannins from gambier. Monosaccharide composition also helped to distinguish among tannin origins: arabinose, xylose, fructose and glucose were quantified in oak, quebracho and chestnut tannins, whereas only fructose and glucose were detected in plant gall and grape tannins. These results imply that the qualitative study of monosaccharides and polyalcohols could help to determine and control the authenticity of enological tannins.     

Photovoltaic potential induced by 10 μm laser radiation in Siphotodiodes

Photon drag and photovoltaic response observed in p⁺/n and n⁺/p silicon junctions excited by moderated-power-density 10-μm radiation are discussed. A multistep multiphotonic process through intermediate states located within the energy gap is proposed as the mechanism responsible for the photovoltaic potential     

Incorporation of Galvanic Waste (Cr, Ni, Cu, Zn, Pb) in a Soda–Lime–Borosilicate Glass

In the present investigation, a glassing process for galvanic waste (GW) incorporation with a high chemical stability is presented. Glasses with up to 50 wt% of galvanic solid waste by modifications in the basic composition of soda–lime–borosilicate glasses were prepared. After fusing at temperatures up to 1300°C, the glasses were characterized by inductively coupled plasma, scanning electron microscopy/energy-dispersive X-ray spectroscopy, high-temperature microscopy, transmission and reflected light microscopy, nuclear magnetic resonance, X-ray photoelectron spectroscopy, and X-ray diffraction methods. The chemical stability was evaluated by hydrolytic attack assays. Glasses containing up to 40 wt% of GW with a very high chemical stability, similar to bottle glasses, were obtained.