Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

International audienceVolcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakes ? Lakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. ? have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO2 occur, and an accumulation of CO2 in the deep water body must be taken into account. Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO2 degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists

Liquid rocket engine axial-flow turbopumps

The axial pump is considered in terms of the total turbopump assembly. Stage hydrodynamic design, pump rotor assembly, pump materials for liquid hydrogen applications, and safety factors as utilized in state of the art pumps are among the topics discussed. Axial pump applications are included

Analytical solution of thermal magnetization on memory stabilizer structures

We return to the question of how the choice of stabilizer generators affects the preservation of information on structures whose degenerate ground state encodes a classical redundancy code. Controlled-not gates are used to transform the stabilizer Hamiltonian into a Hamiltonian consisting of uncoupled single spins and/or pairs of spins. This transformation allows us to obtain an analytical partition function and derive closed form equations for the relative magnetization and susceptibility. These equations are in agreement with the numerical results presented in [arXiv:0907.0394v1] for finite size systems. Analytical solutions show that there is no finite critical temperature, Tc=0, for all of the memory structures in the thermodynamic limit. This is in contrast to the previously predicted finite critical temperatures based on extrapolation. The mismatch is a result of the infinite system being a poor approximation even for astronomically large finite size systems, where spontaneous magnetization still arises below an apparent finite critical temperature. We extend our analysis to the canonical stabilizer Hamiltonian. Interestingly, Hamiltonians with two-body interactions have a higher apparent critical temperature than the many-body Hamiltonian.Comment: 13 pages, 7 figures, analytical solutions of problems studied numerically in arXiv:0907.0394v1 [quant-ph

Diseño de una guía alternativa de técnicas de estudios

PDFHabiendo tomado en cuenta todos los módulos de la maestría, se ha comenzado con la definición del problema es decir el bajo perfil de ingreso específicamente en los estudiantes de la Facultad de Ingeniería Química cuya falta de orientación en sus estudios se convierte en un agravante a la hora de comprender y captar sus clases regulares, pese a que esta es una característica del estudiante de toda la región, se ha pretendido otorgar este trabajo a los estudiantes de esa facultad con la finalidad que estos tengan una orientación más holística hacia el estudio, al lograr la superación de su desempeño se incidirá directamente tanto al ingresar como mientras se desenvuelvan como estudiantes de la Facultad, es entonces necesario indicar que las variables se delimitan al perfil de ingreso y al desempeño académico de los estudiantes teniendo como objetivo general la función de evaluar el perfil inicial del estudiante y a su vez diseñar una guía de estudios que le sirva para mejorar su nivel de comprensión lectora y su procesamiento de información durante los semestres de permanencia en la institución, es necesario recalcar que desde el punto de vista teórico el proyecto tendrá una tendencia dentro del aprendizaje por competencias, la parte metodológica lógicamente estará sustentada por toda la información de datos requeridos y de la información bibliográfica pertinente para que el proyecto mantenga una coherencia y sea factible, luego habrá la necesidad de tabular esos datos que serán recogidos por una muestra debido al alto número de estudiantes y luego tabulados para llegar a una conclusión en base a los datos de la realidad del estudiante, para así llegar a la consecución del diseño de una guía de estudios. Esta guía técnica se pretende que llegue al conocimiento del alumnado primero por medio de afiches o anuncios publicitarios en las diferentes carteleras y luego colgarla dentro de la hoja web de la facultad, así, bajándola en formato digital el alumno la podrá tener siempre en su poder y podrá hacer uso de ella de la mejor manera posible sacándole el provecho debidoHaving born in mind all the modules of the mastery, it has been begun by the definition of the problem is to say the low profile of revenue specifically in the students of the Faculty of Chemical Engineering which lack of orientation in his studies turns into an aggravating factor at the moment of understanding and to catch his regular classes, in spite of that this one is a characteristic of the student of the whole region, one has tried to grant this work to the students of this faculty with the purpose that these have a more holistic orientation towards the study, on having achieved the overcoming of his performance one will affect directly so much on having entered like while be unrolled as students of the Faculty, it is at the time necessarily to indicate that the variables are delimited to the profile of revenue and to the performance, It is at the time necessarily to indicate that the variables are delimited to the profile of revenue and to the academic performance of the students taking as a general aim the function to evaluate the initial profile of the student and in turn designing a guide of studies who serves him to improve his level of reading comprehension and his processing of information during the semesters of permanency in the institution, it is necessary to stress that from the theoretical point of view the project will have a trend inside the learning as competitions, the methodological part logically will be sustained by all the information of needed information and of the bibliographical pertinent information in order that the project supports a coherence and is feasible, then there will be the need to tabulate this information that will be quiet Then there will be the need to tabulate this information that will be gathered by a sample due to the high number of students and then tabulated to come to a conclusion on the basis of the information of the reality of the student, this way to come to the attainment of the design of a guide of studies. This technical guide claims that it comes to the knowledge of the first student body by means of posters or advertising announcements in the different billboards and then to hang it inside the web leaf of the faculty, this way, lowering it in digital format the pupil will be able to have it always in his power and will be able to use her in a best possible way extracting the due prof

Polycyclic aromatic hydrocarbons (PAHs) and soot formation in the pyrolysis of the butanol isomers

The formation of polycyclic aromatic hydrocarbons (PAHs) and soot from the pyrolysis of the four butanol isomers: 1-butanol, 2-butanol, iso-butanol and tert-butanol, at three reaction temperatures (1275, 1375 and 1475 K) has been studied. The identification and quantification of the sixteen PAHs, classified by the Environmental Protection Agency (EPA) as priority pollutants, were done using the gas chromatography–mass spectrometry (GC–MS) technique. The soot formed was collected at the reactor outlet. Light gases formed were also quantified. The harmful potential of the PAHs through the benzoa]pyrene equivalent, Ba]P-eq amount, has been evaluated. The main results show that the highest formation of light gases was obtained from the pyrolysis of iso-butanol at 1275 K. The formation of H2 increases significantly as the temperature increases, following the Hydrogen abstraction carbon addition (HACA) route that leads to form PAHs which subsequently form soot. The tendency to soot formation, under the experimental conditions of the present study, is ranked as follows: tert-butanol, 2-butanol, 1-butanol and iso-butanol. The highest PAHs amount and the highest toxic potential, expressed as Ba]P-eq amount, were found in the pyrolysis of all butanol isomers at 1275 K

Reciprocal regulation by the CepIR and CciIR quorum sensing systems in Burkholderia cenocepacia

<p>Abstract</p> <p>Background</p> <p><it>Burkholderia cenocepacia </it>belongs to a group of closely related organisms called the <it>B. cepacia </it>complex (Bcc) which are important opportunistic human pathogens. <it>B. cenocepacia </it>utilizes a mechanism of cell-cell communication called quorum sensing to control gene expression including genes involved in virulence. The <it>B. cenocepacia </it>quorum sensing network includes the CepIR and CciIR regulatory systems.</p> <p>Results</p> <p>Global gene expression profiles during growth in stationary phase were generated using microarrays of <it>B. cenocepacia cepR</it>, <it>cciR </it>and <it>cepRcciIR </it>mutants. This is the first time CciR was shown to be a global regulator of quorum sensing gene expression. CepR was primarily responsible for positive regulation of gene expression while CciR generally exerted negative gene regulation. Many of the genes that were regulated by both quorum sensing systems were reciprocally regulated by CepR and CciR. Microarray analysis of the <it>cepRcciIR </it>mutant suggested that CepR is positioned upstream of CciR in the quorum sensing hierarchy in <it>B. cenocepacia</it>. A comparison of CepIR-regulated genes identified in previous studies and in the current study showed a substantial amount of overlap validating the microarray approach. Several novel quorum sensing-controlled genes were confirmed using qRT-PCR or promoter::<it>lux </it>fusions. CepR and CciR inversely regulated flagellar-associated genes, the nematocidal protein AidA and a large gene cluster on Chromosome 3. CepR and CciR also regulated genes required for iron transport, synthesis of extracellular enzymes and surface appendages, resistance to oxidative stress, and phage-related genes.</p> <p>Conclusion</p> <p>For the first time, the influence of CciIR on global gene regulation in <it>B. cenocepacia </it>has been elucidated. Novel genes under the control of the CepIR and CciIR quorum sensing systems in <it>B. cenocepacia </it>have been identified. The two quorum sensing systems exert reciprocal regulation of many genes likely enabling fine-tuned control of quorum sensing gene expression in <it>B. cenocepacia </it>strains carrying the cenocepacia island.</p

Exploratory study of polycyclic aromatic hydrocarbons occurrence and distribution in manure pyrolysis products

The occurrence and distribution of polycyclic aromatic hydrocarbons (PAH) have been investigated in the products derived from the pyrolysis of pig manure at low temperatures (<550 °C) in a fixed bed reactor. The focus was on the sixteen PAH identified as priority pollutants by the US Environment Protection Agency (EPA). The pyrolysis does not generate a significant additional amount of EPA-PAH to that existing in the original pig manure, under the operational conditions studied (<550 °C). While the total EPA-PAH yield does not indicate a notable dependence on the pyrolysis temperature, the EPA-PAH distribution among the three pig manure pyrolysis products as well as the speciation changed significantly with the temperature. The proportion of heavy PAH species increased as the temperature increased. The initial EPA-PAH in the manure samples plays a significant role in both their concentration and speciation in the biochar. The relationship of the EPA-PAH concentration and speciation in the biochar with those of the raw material was corroborated with a cow manure sample and the biochars obtained from its pyrolysis. For this reason, feedstocks with low EPA-PAH concentrations are recommended in order to obtain biochars with concentrations below the maximum allowed threshold established for their use as a soil enhancer by the International Biochar Initiative (IBI) and in the European Biochar Certificate

Design of a photovoltaic power plant connected to the grid to cover the daytime energy demand of the Jenmer cia ltda service station

The work presents an analysis linked to one of the sustainable energy alternatives that are currently being adopted with success worldwide. Putting the field research method into practice, the results of a study related to an application of technological innovation are shown to reduce the amount of the electricity bill at the JENMER CIA LTDA Service Station, through the introduction of photovoltaic technology connected to the low voltage network of the institution. The results of the study of load and hourly energy consumption of said entity are shown and its methodology is deployed for the technological design of a photovoltaic plant connected to the grid, which can avoid the energy consumption of the conventional grid, reducing the amount of the electricity bill of the institution, at the same time that it is possible to reduce losses, improve the quality of electricity service and reduce COemissions2 into the atmosphere. The energy, economic, environmental, and social impacts associated with the penetration of photovoltaic technology are exposed

Desarrollo energético local en función de la mitigación al cambio climático / Local energy development as a function of climate change mitigation

En un clima social donde apenas se conozca medianamente la evolución histórica de la situación ambiental del planeta en los últimos trescientos años, no se discute la necesidad de proteger la vida de las consecuencias derivadas del progreso social. Ahora el debate se centra en cómo se pudiera proteger la vida tal y como se conoce y en ese caso no es difícil advertir, que bajo los esquemas tradicionales no será posible alcanzar las metas del desarrollo sostenible. En el trabajo se muestra un análisis conceptual sobre los antecedentes históricos del desarrollo energético local, donde la influencia de las políticas económicas operadas durante las transiciones energéticas, fueron relegando cualquier vestigio de soluciones de tipo local, invisibilizando el papel del territorio y las localidades en el destino energético de la sociedad, imponiéndose un modelo de desarrollo centralizado que se sustentó cada vez más en el consumo de recursos naturales fósiles, con una industria ineficiente y contaminadora por excelencia. Se exponen los principales impactos ambientales derivados de esta política; así como otras consecuencias en el orden económico, político y social. Se muestran los resultados preliminares obtenidos del proyecto SIGDES (Sistema de Información Geográfica para el Desarrollo Sostenible), relacionados con el estudio de los potenciales renovables en la provincia de Manabí y se argumenta la necesidad de acoger un modelo de desarrollo energético que adopte como paradigma los conceptos asociados al desarrollo local y el aprovechamiento adecuado de los recursos endógenos

Proyecto de diseño de un condensador con fuente eólica para obtención de agua

This document deals with the description of a project to obtain a vital resource, water. Water is the most important resource in the daily life of humanity. This project attempts to compensate for the lack of access to this resource by vapor condensation present in the air. The need to do this work was seen, given that, due to earthquakes, coastal areas were affected, destroying buildings and distribution pipes of this vital product; which left the affected areas in very precarious conditions. The objective of this work is to show how to condense water, clean and of quality for human consumption, by means of a condensation device, to cover the most vital needs, which are daily hydration, disease prevention and food preparation. In this way, the temperature differential between the air and the ground is the key factor in the design, since it occurs naturally without any extra energy contribution. In history, different mechanisms of condensation have been generated, the most efficient do not take into account the relative humidity of the air, but reach the dew point by changing the temperature. This is the mechanism of operation of the project. This work was designed for the mountain area of the country and from this, work can be extrapolated to a warmer area.Este documento aborda a descrição de um projeto para obter um recurso vital, a água. A água é o recurso mais importante no cotidiano da humanidade. Este projeto procura compensar a falta de acesso a este recurso por condensação de vapor presente no ar. A necessidade de fazer este trabalho foi vista, dado que, devido a terremotos, as áreas costeiras foram afetadas, destruindo edifícios e tubos de distribuição deste produto vital; que deixou as áreas afetadas em condições muito precárias. O objetivo deste trabalho é mostrar como condensar água, limpar e de qualidade para consumo humano, por meio de um dispositivo de condensação, para cobrir as necessidades mais vitais, que são hidratação diária, prevenção de doenças e preparação de alimentos. Desta forma, o diferencial de temperatura entre o ar eo solo é o fator chave no projeto, pois ocorre naturalmente sem qualquer contribuição de energia extra. Na história, foram gerados diferentes mecanismos de condensação, os mais eficientes não levam em conta a umidade relativa do ar, mas atingem o ponto de orvalho alterando a temperatura. Este é o mecanismo de operação do projeto. Este trabalho foi projetado para a região montanhosa do país, e disso, o trabalho pode ser extrapolado para uma área mais quente.Este documento trata la descripción de un proyecto para conseguir un recurso vital, el agua. El agua es el recurso más importante en la vida diaria de la humanidad. Este proyecto intenta compensar la falta de acceso a este recurso mediante condensación de vapor presente en el aire. Se vio la necesidad de hacer este trabajo, dado que, por terremotos, zonas costeras se vieron afectadas, destruyendo edificaciones y tuberías de distribución de este producto vital; lo cual dejó en muy precarias condiciones las zonas afectadas. El objetivo de este trabajo es mostrar cómo condensar agua, limpia y de calidad para el consumo humano, mediante un dispositivo de condensación, para cubrir las necesidades más vitales, que son hidratación diaria, prevención de enfermedades y preparación de alimentos. De esta manera, el diferencial de temperatura entre el aire y el suelo, es el factor clave en el diseño, ya que se da de manera natural sin ningún aporte energético extra. En la historia se han generado distintos mecanismos de condensación, los más eficientes no toman en cuenta la humedad relativa del aire, sino alcanzar el punto de rocío cambiando la temperatura. Este es el mecanismo de funcionamiento del proyecto. Este trabajo fue diseñado para la zona serrana del país, y a partir de este, se puede extrapolar el trabajo para una zona más cálida