Analytical model for BTEX natural attenuation in the presence of fuel ethanol and its anaerobic metabolite acetate

Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Contaminant Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Contaminant Hydrology Vol. 146 (2013), DOI: 10.1016/j.jconhyd.2012.12.006Flow-through column studies were conducted to mimic the natural attenuation of ethanol and BTEX mixtures, and to consider potential inhibitory effects of ethanol and its anaerobic metabolite acetate on BTEX biodegradation. Results were analyzed using a one-dimensional analytical model that was developed using consecutive reaction differential equations based on first-order kinetics. Decrease in pH due to acetogenesis was also modeled, using charge balance equations under CaCO3 dissolution conditions. Delay in BTEX removal was observed and simulated in the presence of ethanol and acetate. Acetate was the major volatile fatty acid intermediate produced during anaerobic ethanol biodegradation (accounting for about 58% of the volatile fatty acid mass) as suggested by the model data fit. Acetate accumulation (up to 1.1 g/L) near the source zone contributed to a pH decrease by almost one unit. The anaerobic degradation of ethanol (2 g/L influent concentration) at the source zone produced methane at concentrations exceeding its solubility (≅ 26 mg/L). Overall, this simple analytical model adequately described ethanol degradation, acetate accumulation and methane production patterns, suggesting that it could be used as a screening tool to simulate lag times in BTEX biodegradation, changes in groundwater pH and methane generation following ethanol-blended fuel releases

The Noncommutative Supersymmetric Nonlinear Sigma Model

We show that the noncommutativity of space-time destroys the renormalizability of the 1/N expansion of the O(N) Gross-Neveu model. A similar statement holds for the noncommutative nonlinear sigma model. However, we show that, up to the subleading order in 1/N expansion, the noncommutative supersymmetric O(N) nonlinear sigma model becomes renormalizable in D=3. We also show that dynamical mass generation is restored and there is no catastrophic UV/IR mixing. Unlike the commutative case, we find that the Lagrange multiplier fields, which enforce the supersymmetric constraints, are also renormalized. For D=2 the divergence of the four point function of the basic scalar field, which in D=3 is absent, cannot be eliminated by means of a counterterm having the structure of a Moyal product.Comment: 15 pages, 7 figures, revtex, minor modifications in the text, references adde

Botanical composition of cattle diet on rangelands in the Pantanal wetland, Brazil

O estudo foi conduzido com o objetivo de identificar a composição botânica da dieta de bovinos criados extensivamente no Pantanal através da técnica microhistológica fecal, numa área característica da sub-região da Nhecolândia, Pantanal, no período de outubro/97 a setembro/99, e verificar a variação existente em função do mês, época, ano e estado fisiológico das vacas. Foram confeccionadas 726 lâminas, sendo cada lâmina uma unidade observacional. Com base na distribuição dos valores máximos de ocorrência da composição botânica de cada espécie/lâmina e nos quantis, as espécies foram classificadas em quatro grupos principais: 1- principal (máx >20%); 2- médio superior (12,3% 20.0%); 2- medium superior (12.3% <max<=20.0%); 3- medium (6.7<max<=12.3%); 4-occasional (max<+6.7%). These groups represented 11%, 14%, 25% and 50% of the identified species, respectively. A split-plot in distinct time was adjusted envolving each effect (month, season) and its interactions with physiological condition and hydrological year. For all studied groups there were no significant effects of physiological condition of cows and no interaction of physiological condition with period and year on the mean composition of the diet. There were significant effects of season and year for all groups, however, the interaction season x year was significant only for the occasional group

An approach to dynamic line rating state estimation at thermal steady state using direct and indirect measurements

Dynamic line rating has emerged as a solution for reducing congestion in overhead lines, allowing the optimization of power systems assets. This technique is based on direct and/or indirect monitoring of conductor temperature. Different devices and methods have been developed to sense conductor temperature in critical spans. In this work, an algorithm based on WLS is proposed to estimate temperature in all ruling spans of an overhead line. This algorithm uses indirect measurements - i.e. weather reports and/or downscaling nowcasting models as inputs as well as direct measurements of mechanical tension, sag and/or conductor temperature. The algorithm has been tested using typical atmospheric conditions in Iceland along with an overhead line´s real design, showing robustness, efficiency and the ability to minimize error in measurements.Fil: Alvarez, David L.. Universidad Nacional de Colombia; ColombiaFil: Faria da Silva, F.. Aalborg Universitet; DinamarcaFil: Mombello, Enrique Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Bak, Claus Leth. Aalborg Universitet; DinamarcaFil: Rosero, Javier A.. Universidad Nacional de Colombia; ColombiaFil: Ólason, Daníel Leó. Landsnet; Islandi

The seminal plasma proteins Peptidyl arginine deaminase 2, rRNA adenine N (6)-methyltransferase and KIAA0825 are linked to better motility post thaw in stallions

Seminal plasma plays an important role in sperm physiology. Seminal plasma proteins vehiculated in microvesicles, carry RNAs and proteins with a potential role in early embryo development. Additionally, proteins present in seminal plasma participate in redox regulation and energy metabolism. In view of these facts, we hypothesized that differences in protein composition of the seminal plasma among stallions may help to explain differences in freeze-ability seen among them. Three independent ejaculates from 10 different stallions of varying breeds were frozen using standard protocols in our laboratory. Aliquots of the ejaculate were separated and stored at −80 °C until further proteomic analysis. Semen analysis was performed using computer assisted sperm analysis and flow cytometry. Significant differences in proteome composition of seminal plasma were observed in the group of stallions showing better motility post thaw. 3116 proteins were identified, and of these, 34 were differentially expressed in stallions with better motility post thaw, 4 of them were also differentially expressed in stallions with different percentages of linearly motile sperm post thaw and 1 protein, Midasin, was expressed in stallions showing high circular velocity post thaw. Seminal plasma proteins may play a major role in sperm functionality; being vehiculated through extracellular vesicles and participating in sperm physiology. Bioinformatic analysis identifies discriminant proteins able to predict the outcome of cryopreservation, identifying potential new biomarkers to assess ejaculate quality

Discriminación entre poblaciones de abejas (apis mellifera L.) del sur de España, centro de Portugal y Madeira

Tradicionalmente se ha considerado que las abejas que viven en la Península Ibérica pertenecen a la raza Apis mellifera iberica, que se encuentra emparentada con la raza A. m. intermissa que coloniza el norte de África y la raza A. m. mellifera originaria de Europa occidental. Las abejas obreras procedentes de España y Portugal, se han descrito como animales de color azabache, con pilosidad y tomento de tamaño mediano, y una probóscide bastante larga; encontrando algunos autores que los animales del sur tenían una pilosidad más corta y una probóscide más larga, que sus familiares procedentes del norte. En el presente trabajo hemos estudiado 34 muestras de abejas obreras procedentes de dos zonas de nuestra península (el sur de España y el centro de Portugal), y del Archipiélago de Madeira, para rastrear la existencia de posibles diferencias morfológicas. Los resultados muestran que los animales constituyen tres grupos morfológicos, identificables mediante un análisis canónico. Uno de ellos incluye a los procedentes del centro de Portugal, otro está formado por los oriundos de Córdoba, y el tercero está constituido por los procedentes de la isla de Madeira y de la Sierra de Cazorla

Biometric study of apis mellifera population from central Portugal and Madeira

Las abejas melíferas que habitan en la Península Ibérica han sido descritas tradicionalmente como pertenecientes a la raza Apis mellifera iberica. La raza iberica está constituida por animales de color oscuro y de un gran vigor, su comportamiento es algo nervioso y la enjambraz .n se considera como moderada. Desde un punto de vista morfológico, son pocos los trabajos en los que se han estudiado estos seres vivos, incluyendo la bibliografía existente descripciones más o menos extensas de los que habitan en la región mediterránea, Asturias y la Submeseta Norte. Si admitimos que diferentes condiciones climáticas han debido de tener efectos selectivos sobre las características de estos insectos, resulta muy interesante estudiar abejas procedentes de diferentes localizaciones, para conocer la variabilidad existente. En el presente trabajo hemos estudiado 16 caracteres morfológicos, en 18 muestras de abejas obreras oriundas del centro de Portugal y de la isla de Madeira. Los resultados indican que las abejas del centro de Portugal constituyen un grupo morfológico, en el que no se aprecian grandes diferencias entre las distintas localizaciones geográficas. Los animales procedentes de Madeira también forman un conjunto morfológico, en el que, cuando se estudia de forma conjunta con las muestras procedentes de Portugal, el análisis canónico muestra un solapamiento parcial de las poblaciones