363 research outputs found
Angiosperm pollen grains from the Cuayuca Formation (Late Eocene to Early Oligocene), Puebla, Mexico
Systematic descriptions and illustrations of the best preserved angiosperm pollen
grains (Monocotyledonae or Liliopsida: n= 7 and Dicotyledonae or Magnoliopsida: n=
41) recovered from Cuayuca Formation (late Eocene-early Oligocene), Puebla State,
Mexico are provided, some of them of chronostratigraphic importance (Aglaoreidia
pristina, Armeria, Bombacacidites, Corsinipollenites, Eucommia, Favitricolporites,
Intratriporopollenites, Lymingtonia, Magnaperiporites, Malvacipollis spinulosa, Margocolporites
aff. vanwijhei, Momipites coryloides, Momipites tenuipolus, Mutisiapollis,
Ranunculacidites operculatus, and Thomsonipollis sabinetownensis). Taxa identified
from the Cuayuca Formation suggest local semiarid vegetation such as tropical deciduous
forest, chaparral, grassland, and arid tropical scrub, in which angiosperms are
one of the main representatives. Nevertheless, temperate taxa from Pinus forest and
cloud forest were also registered from regional vegetation. It is noticeable that at the
present time, such taxa are well represented in the vegetation of the Balsas River
Basin, which would suggest the existence of this type of flora in the Cuayuca region
since the Oligocene.Fil: Ramirez Arriaga, Elia. Universidad Nacional Autónoma de México. Instituto de Geología. Departamento de Paleontología; MéxicoFil: Pramparo, Mercedes Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Martínez Hernández, Enrique. Universidad Nacional Autónoma de México. Instituto de Geología. Departamento de Paleontología; Méxic
Study of a torus bioreactor for the enzymatic elimination of phenol
Phenols are priority pollutants that are commonly found in a large number of industrial wastewaters. Different processes are currently available for the elimination of phenol from wastewater but present some disadvantages like low efficiency, high energy-consumption, the necessity of acclimatisation of the sludges or the limitation of the treatment capacity. The need to find alternatives has made the enzymatic processes a good option. In the last two decades, several processes were implemented with different enzymes from plants and microorganisms, including peroxidases from several sources, as the horseradish peroxidase.Also, different enzyme configurations, free or immobilised enzyme and different supports for immobilisation have been studied. Substantial attention has been devoted to the covalent immobilisation of enzymes on porous insoluble supports such as glass, alumina, silica, and chitosan.The main novelty of this work is the utilisation of a torus reactor for the removal of organic contaminants from wastewaters. This reactor, which can be considered as a loop reactor, presents some advantages over other stirred tank reactors.The goal of this work is the study of the hydrodynamics of a torus reactor for its further application in the enzymatic elimination of phenol and the coupling of the kinetics and the modelisation.In a first step, the enzymatic elimination of phenol was experimentally studied in the torus reactor. In order to compare the performances, several assays were also carried out with a stirred reactor. A high degree of conversion was obtained for the enzymatic elimination of phenol in both reactors with the tested quantities of phenol. It was concluded that, keeping a ratio of 1:1 between the phenol and the H2O2 initial molar quantities, the highest final reaction conversion was obtained. Using the torus reactor was obtained 97% of phenol conversion when the optimal concentrations of substrates were usedIn order to improve economically the process, the enzyme should be used in a continuous regime over a long time period to exploit it completely. For this reason it was necessary to immobilise the enzyme. This work presents a new configuration that has never been tested: the horseradish peroxidase supported on Eupergit.In a second step, the characterisation using the CFD of the flow-field in a torus reactor of 100 ml, similar to the experimental reactor, was carried out for two different configurations, batch and continuous operating modes. Moreover, the scale-up of the volume of the torus reactor was carried out using CFD for a 300 ml reactor.Finally, the enzymatic reaction of phenol with the HRP was modelled using the CFD coupled to the kinetic model of the enzymatic reaction to the flow simulation. These results allowed the possibility of optimising and scaling-up the process using the CFD modelisation.Los compuestos fenólicos son contaminantes prioritarios que se encuentran comúnmente en una gran cantidad de efluentes industriales. Diferentes procesos están disponibles actualmente para la eliminación de fenol desde dicho efluentes pero los mismos presentan algunas desventajas como pueden ser una baja eficiencia, un mayor consumo de energía, la producción de lodos conteniendo hierro o limitaciones en la capacidad de tratamiento. La necesidad de encontrar alternativas a estos problemas ha hecho del proceso enzimático una buena opción. En las últimas dos décadas, varios procesos han sido implementados utilizando diferentes enzimas extraídas de plantas y microorganismos como pueden ser las peroxidasas de diversas fuentes, incluyendo la horseradish peroxidasa.Diferentes configuraciones de enzimas, libre e inmovilizada y diferentes soportes para la inmovilización han sido también estudiados. Sustancial atención ha sido dedicada a la inmovilización de enzimas por enlace covalente sobre soportes porosos insolubles tales como vidrio, aluminio, sílice y chitosan. El objetivo de este trabajo es el estudio de la hidrodinámica dentro de un reactor tórico para su posterior aplicación en la eliminación enzimática de fenol y el acople entre las cinéticas y la modelización.En una primera etapa, la eliminación enzimática de fenol es estudiada experimentalmente en el reactor tórico. Con el objetivo de comparar el rendimiento de dicho reactor, varios ensayos se realizaron en un reactor agitado tradicional. Un alto grado de conversión de fenol ha sido obtenido para la eliminación enzimática de fenol en ambos reactores para las cantidades estudiadas de fenol. Ha sido observado que es necesario mantener una relación de 1:1 entre la concentración inicial de fenol y la de peróxido de hidrógeno para lograr la mayor conversión de fenol. Usando el reactor tórico ha sido obtenido un 97% de conversión de fenol cuando las concentraciones óptimas de substratos y enzimas fueron utilizados. Con el objetivo de mejorar económicamente el proceso y hacerlo factible para su uso a escala industrial, la enzima debería ser utilizada en un proceso en continuo sobre un largo período de tiempo para explotarla completamente. Por esta razón, ha sido necesario inmovilizar la enzima. Este trabajo muestra una nueva configuración que no ha sido aún probada: la horseradish peroxidase soportada en Eupergit. Asimismo, la caracterización usando CFD del campo de flujo de un reactor tórico similar al experimental de 100 ml ha sido realizada para un reactor trabajando de forma batch y continua. Un escalado en el volumen del reactor tórico ha sido realizado utilizando CFD para un reactor de 300 ml. Finalmente, la reacción enzimática de fenol con HRP has sido modelada acoplando el modelo cinético obtenido experimentalmente con las simulaciones del campo de flujo dentro del reactor. Estos resultados permitirán la optimización y el escalado del proceso usando CFD
First palynologic record of the Cretaceous La Yesera Formation (Salta Group), northwestern Argentina
Thirty-four taxa were documented from six palynologically productive samples of the La Yesera Formation (Brealito and Don Bartolo Members) in the Pucará locality (Salta Province, northwestern Argentina). In the Brealito Member, aquatic species (mainly freshwater algae) dominate the palynofl ora, while terrestrial species are represented by trilete spores (mainly Anemiaceae) and gymnosperm pollen grains. In the Don Bartolo Member, Classopollis spp. dominate most of the assemblages, trilete Anemiaceae spores constitute half of the total counts in one of the assemblages and a unique angiosperm species (Tricolpites variabilis) was found in two assemblages. Ephedra-type pollen grains (three genera and six species) appear in both members, although in low abundance. The results support previous sedimentology studies that indicate a perennial lake environment at the time of deposition of the Brealito Member, with evidence for dry seasonality in the Don Bartolo Member. The inferred regional paleoclimate is subtropical with arid conditions. Considering the stratigraphic ranges of selected species and the sedimentology data, an Albian/Cenomanian age is suggested for the unit.Trinta e quatro táxons foram registrados a partir de seis amostras palinológicas provenientes da Formação La Yesera (membros Brealito e Don Bartolo), na localidade Pucará, Província de Salta, noroeste da Argentina. No Membro Brealito, predominam as espécies aquáticas, principalmente de algas de água doce; as espécies terrestres estão representadas por esporos triletes, principalmente de Anemiaceae e por grãos de pólen de gimnospermas. No Membro Don Bartolo, os grãos de pólen Classopollis spp. dominam a maioria das assembleias, embora numa das amostras, metade das contagens totais é constituída por esporos triletes de Anemiaceae e, uma única espécie de angiospermas (Tricolpites variabilis) foi encontrada em duas assembleias. Grãos de pólen do tipo Ephedra, com três gêneros e seis espécies, aparecem em baixa abundância em ambos os membros. Estes resultados corroboram estudos sedimentológicos anteriores e indicam ambiente lacustre perene, no momento da deposição do Membro Brealito, com evidência de sazonalidade seca para a Membro Don Bartolo. O paleoclima regional inferido é subtropical árido. Considerando os intervalos estratigráfi cos de espécies selecionadas e os dados sedimentológicos, é sugerida idade Albiano/Cenomaniano para a unidade estudada.Fil: Narvaez, Paula Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Pramparo, Mercedes Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Sabino García, Ignacio Federico. Tecpetrol S. A.; Argentin
Methodology for predicting oily mixture properties in the mathematical modeling of molecular distillation
A methodology for predicting the thermodynamic and transport properties of a multi-component oily mixture, in which the different mixture components are grouped into a small number of pseudo components is shown. This prediction of properties is used in the mathematical modeling of molecular distillation, which consists of a system of differential equations in partial derivatives, according to the principles of the Transport Phenomena and is solved by an implicit finite difference method using a computer code. The mathematical model was validated with experimental data, specifically the molecular distillation of a deodorizer distillate (DD) of sunflower oil. The results obtained were satisfactory, with errors less than 10% with respect to the experimental data in a temperature range in which it is possible to apply the proposed method.Fil: Gayol, Maria Fernanda. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Pramparo, Maria del Carmen. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Miro Erdmann, Silvia M.. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias; Argentin
Use of Native Microorganisms as an Alternative for Biological Removal of Organic Matter in Wastewater from the Pharmaceutical Industry
The impact of non-domestic wastewater (nDWW) on water bodies every day is increased, considering the different pollutants that are entering and these are not regulated, also that the effects of these are not known in the ecosystems. In the case of the pharmaceutical industry, the various products they generate can contribute from non-steroidal anti-inflammatory analgesics (NSAIDs), antihypertensives, hormones, antibiotics, among others; they are being detected in surface waters and it is necessary to create strategies to improve treatment systems and thus reduce their effects on water systems. In this work, the native microorganisms from nDWW of the pharmaceutical industry were used to evaluate their ability to influence the removal of organic matter, working in mixed culture, where it was evidenced that in a 24 hours they could remove 45.82 % of the organic matter measured by the chemical oxygen demand (COD) and at 48 hours 90.59 % removal. The above shows that the use of microorganisms can contribute to the reduction of COD and pollutants in an effective, environmentally friendly and, more efficient way than conventional methods. Besides, the qualities of tolerance to four NSAIDs by 16 morphotypes are evidenced, and how they can be profiled in the future to be potentialized and reach the mineralization of these emerging pharmaceutical pollutants
Recommended from our members
The ASD Living Biology: from cell proliferation to clinical phenotype.
Autism spectrum disorder (ASD) has captured the attention of scientists, clinicians and the lay public because of its uncertain origins and striking and unexplained clinical heterogeneity. Here we review genetic, genomic, cellular, postmortem, animal model, and cell model evidence that shows ASD begins in the womb. This evidence leads to a new theory that ASD is a multistage, progressive disorder of brain development, spanning nearly all of prenatal life. ASD can begin as early as the 1st and 2nd trimester with disruption of cell proliferation and differentiation. It continues with disruption of neural migration, laminar disorganization, altered neuron maturation and neurite outgrowth, disruption of synaptogenesis and reduced neural network functioning. Among the most commonly reported high-confidence ASD (hcASD) genes, 94% express during prenatal life and affect these fetal processes in neocortex, amygdala, hippocampus, striatum and cerebellum. A majority of hcASD genes are pleiotropic, and affect proliferation/differentiation and/or synapse development. Proliferation and subsequent fetal stages can also be disrupted by maternal immune activation in the 1st trimester. Commonly implicated pathways, PI3K/AKT and RAS/ERK, are also pleiotropic and affect multiple fetal processes from proliferation through synapse and neural functional development. In different ASD individuals, variation in how and when these pleiotropic pathways are dysregulated, will lead to different, even opposing effects, producing prenatal as well as later neural and clinical heterogeneity. Thus, the pathogenesis of ASD is not set at one point in time and does not reside in one process, but rather is a cascade of prenatal pathogenic processes in the vast majority of ASD toddlers. Despite this new knowledge and theory that ASD biology begins in the womb, current research methods have not provided individualized information: What are the fetal processes and early-age molecular and cellular differences that underlie ASD in each individual child? Without such individualized knowledge, rapid advances in biological-based diagnostic, prognostic, and precision medicine treatments cannot occur. Missing, therefore, is what we call ASD Living Biology. This is a conceptual and paradigm shift towards a focus on the abnormal prenatal processes underlying ASD within each living individual. The concept emphasizes the specific need for foundational knowledge of a living child's development from abnormal prenatal beginnings to early clinical stages. The ASD Living Biology paradigm seeks this knowledge by linking genetic and in vitro prenatal molecular, cellular and neural measurements with in vivo post-natal molecular, neural and clinical presentation and progression in each ASD child. We review the first such study, which confirms the multistage fetal nature of ASD and provides the first in vitro fetal-stage explanation for in vivo early brain overgrowth. Within-child ASD Living Biology is a novel research concept we coin here that advocates the integration of in vitro prenatal and in vivo early post-natal information to generate individualized and group-level explanations, clinically useful prognoses, and precision medicine approaches that are truly beneficial for the individual infant and toddler with ASD
Willingness to pay of tourists for co2 offsetting; a survey for the organization of a green fund in the Euganean Hills area.
ope
Estudio de sistemas de destrucción catalítica de compuestos orgánicos volátiles
El aumento en la contaminación del aire ha convertido al control de la polución en uno de los objetivos prioritarios a analizar desde la investigación, el desarrollo de tecnologías y la puesta en marcha de las regulaciones ambientales vigentes. Uno de los objetivos primordiales es el de disminuir las emanaciones de gases de efecto invernadero a la atmósfera.
Entre los contaminantes del aire más comunes, se encuentran los Compuestos Orgánicos Volátiles (COVs) emitidos desde la industria química, petroquímica y desde otras relacionadas; los mismos pueden generar oxidantes fotoquímicos, tales como el ozono, ante la presencia de óxidos de nitrógeno (NOX) y de radiación ultravioleta (UV). La presencia de ozono en la atmósfera, incluso en concentraciones muy bajas, favorece las enfermedades respiratorias, como el asma, afecta a la producción agrícola e incrementa los efectos nocivos del smog fotoquímico, ya que es uno de sus principales constituyentes.
En cuanto a los efectos nocivos de los COVs y de los CCOVs (Compuestos Orgánicos Volátiles Clorados) sobre el Medio Ambiente y la salud, cabe mencionar que son considerados contaminantes altamente peligrosos debido a su alta volatilidad, persistencia en el aire y capacidad para viajar grandes distancias desde sus puntos de emisión. Además, son agentes de efecto invernadero más efectivos que el CO2 y poseen acción química nociva propia, es decir, son promotores de enfermedades tales como el cáncer, las afecciones respiratorias y neuronales, etc.
Por todo lo anterior, y de acuerdo a la creciente preocupación de la sociedad ante la problemática medioambiental y el cambio climático, el control de las emisiones de éstos y de otros contaminantes, no sólo al aire, sino también al agua y al suelo, se rige de una normativa cada vez más rigurosa y precisa, con origen en los países más industrializados del hemisferio norte del globo.
Muchas de las sustancias transformadas o producidas en la industria son o están formadas por COVs o CCOVs, tales como: el petróleo, los solventes, las pinturas, los adhesivos, los lubricantes, los combustibles, etc. Las imprentas, particularmente las pertenecientes a industrias que elaboran envases para sus productos alimenticios en distintos materiales (polipropileno, poliester, etc.), los cuales llevan la respectiva impresión en sus superficies, liberan al ambiente corrientes gaseosas contaminadas con compuestos como acetato de etilo y, en menor proporción, etanol.
En este trabajo se presenta el estudio de viabilidad técnica de la solución a esta problemática medioambiental que las empresas de impresión de envases deben enfrentar en la actualidad: la emisión de Compuestos Orgánicos Volátiles (COVs) a la atmósfera. En las mismas, dos de los compuestos usualmente empleados son el acetato de etilo y el etanol. Por lo tanto, la eliminación de estas sustancias en un efluente gaseoso será el eje central del estudio. Bajo esta premisa, el objetivo de esta tesis es seleccionar una tecnología adecuada para las condiciones del efluente a tratar, y posteriormente su profundización científica en el estudio detallado teórico-experimental correspondiente para aportar información necesaria para nuevos desarrollos tecnológicos.Material digitalizado en SEDICI gracias a la Biblioteca de la Facultad de Ingeniería (UNLP).Facultad de Ingenierí
The use of artificial neural network modeling to represent the process of concentration by molecular distillation of omega-3 from squid oil
- …