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"In this study, the response surface methodology (RSM) with central composite design (CCD) was employed to improve the hydrogen production by the psychrophilic N92 strain (EU636058) isolated from Antarctica, which is closely related to Pseudorhodobacter sp. (KT163920). The influence of operational conditions such as temperature (4.7–55.2 °C), initial pH (3.44–10.16), and initial glucose concentration (4.7–55.23 g/dm3), as well as the initial concentrations of (NH4)2SO4 (0.05–3.98 g/dm3), FeSO4 (0.02–1.33 g/dm3) and NaHCO3 (0.02–3.95 g/dm3) was evaluated. The linear effect of glucose concentration, along with the quadratic effect of all the six factors were the most significant terms affecting the biohydrogen yield by N92 strain. The optimum conditions for the maximum hydrogen yield of 1.7 mol H2/mol glucose were initial pH of 6.86, glucose concentration of 28.4 g/dm3, temperature 29 °C and initial concentration of (NH4)2SO4, FeSO4 and NaHCO3 of 0.53, 1.55 and 1.64 g/dm3 respectively. Analysis of the metabolites produced under the optimum conditions showed that the most abundant were acetic acid (0.8 g/dm3), butyric acid (0.7 g/dm3) and ethanol (2.1 g/dm3). We suggest that the bioprocess established in this study using the strain N92 could be an alternative for hydrogen production with the advantages of constituting low energy costs in fermentation."
BaTiO3-CoFe2O4 composites synthesized by the ceramic method showed a magnetoelectric effect. The CoFe2O4 powders were synthesized by coprecipitation and mixed with Aldrich reactive quality BaTiO3 powders with particle size <2 μm. The coupling of the magnetostrictive and the piezoelectric phases via elastic deformations of the properly polarized composites produced a magnetoelectric effect. The starting powders and the composites were characterized by thermal analysis, x-ray diffraction with Reitveld refinements, scanning electron microscopy and particle size distribution using light scattering. The magnetoelectric coefficient, α = dE/dH, was measured using the dynamic method, and a new pulsed magnetic field method developed in our laboratory.
En este proyecto se muestra el proceso de fabricación de uno deloscuatro álabes de unmetro de alturaque se adaptarán a un rotor de eje vertical para un generador eólico, se utilizó un composite fibrosoel cual se conforma por un refuerzo y una matriz para el refuerzose optó por utilizar fibra de vidrio por su precio y sus propiedades adecuadas para el proceso, como matriz se utilizó resina epoxica. El proceso de fabricación utilizado VARTM (Vacuum assisted resin transfer molding)o proceso de moldeo por transferencia de resina asistido de vacío, se utilizó por ser un método efectivo y preciso ya que el álabe requiere de un acabado uniformetanto como superficies lisasy este proceso es ideal para la fabricación del álabe.Los resultados fueronpróximos a los quese esperaron, la superficie del álabe uniforme y con rugosidad mínimay la forma estructural propuesta, el proceso fue eficientey puede mejorarse para los álabes que se fabricarán posteriormente
In this project is shown the manufacturing process of one of the four blades of a meter in height to adapt to a vertical axis rotor for a wind generator, was used a fiber composite which is formed by a reinforcement and a matrix was used as strengthening and chose to used fiberglass for its price and suitable for the process, the epoxy resin matrix was used by its properties. The manufacturing process used VARTM (Vacuum assisted resin transfer molding) was used by be an effective and accurate method since the blade requires an even finish and this process is ideal for blade manufacture. The results were close to those expected, the blade surface with uniform roughness was minimal, and the way structural was the proposal, the process is efficient and can be improved for the blades which is subsequently manufactured
"The synthesis of MnxZn1-xFe2O4 ferrites (x = 0.4, 0.5 and 0.6) by means of the co-precipitation method is reported. Furthermore, a composite of Mn0.4Zn0.6Fe2O4/activated carbon was prepared with the mechanosynthesis method. The magnetic, structural, morphological and chemical properties were analyzed by means of VSM, XRD, SEM, FTIR and Boehm's titration. The heating capacity was evaluated under a magnetic field using solid-state induction heating equipment, in addition a hemolysis test was performed using human red blood cells. With regard to the synthesis of manganese-zinc ferrite, the results indicated that Mn0.4Zn0.6Fe2O4 ferrite showed higher saturation magnetization (64.48 emu/g) than the other ferrite obtained, with superparamagnetic behavior. The Mn0.4Zn0.6Fe2O4/activated carbon composite was able to heat in concentrations of 10 mg/ml under a magnetic field (10.2 kAm-1 and frequency 200 kHz), increasing the temperature up to 42.5 °C. The hemolysis test indicated that the presence of activated carbon reduces the hemolytic behavior of the ferrite. Thanks to its heating capacity and non-hemolytic activity, theMn0.4Zn0.6Fe2O4/activated carbon composite is a potential candidate for use in biomedical applications."
The sorption behaviors of biosorbent based on maize (Zea mays, ZM) cane (bagasse and stalk), their composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles for malachite green from aqueous solutions were investigated in this work. Adsorbents were characterized using BET, infrared spectroscopy, X-ray diffraction, SEM-EDS, and Fe-Cu nanoparticles were characterized by TEM. The study of the sorption kinetics indicates that the adsorption on malachite green by stalk and their composite follows second-order kinetics and nanoparticles and bagasse and their composite follow the pseudo-second order model. The malachite green adsorption by ZM/Fe-Cu composites were faster than natural materials and only showed two phases in the intraparticle diffusion model, probably due to the minor internal diffusion resistance. The adsorption isotherms experimental data were analyzed by the Langmuir, Freundlich and Langmuir–Freundlich models and the equilibrium data was well described by the Langmuir–Freundlich isotherm model. The adsorption was more favorable at basic pH. The OH-groups were proportional to dye adsorption capacities. Results showed that composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles possessed good adsorption abilities to malachite green.
Project 3688/2014/CIB UAEM
Designing a formal speech, an idea or structure of ideas that give origin, demands a concept. This activity is seen as a process that articulates a coherent concept; its formal synthesis, the expression or conceptual projection in an object shape is never the same under question from various backgrounds. As it can be seen, the project proposal begins with the investigation of a topic in relation to the context and the potential consumer. Later this information is used to represent a mental idea –colors, lines, dots, shapes, as language–, and then it is written or represent it as a sketch, in order to create the final concept of the design object. Once this is done, the graphical representation of the concept is initiated by the elements of visual alphabet, usually in specialized computer software. Then, in a sustainable way, production is manufactured and distribution programmed –implantation–. Finally, an evaluation of the work is perform from its substance, emphasizing the importance of systematic and methodological research to its conceptualization in order to represent the argumentative way, besides observing the topic of Social Responsibility.
Scientific research is an extremely important issue not only for general and particular knowledge of sciences and disciplines, but also it supports the reflection of the investigated issue with the purpose of expanding the known. At the same time, deliberation about what it has been investigated represents a fertile field of development possibilities of understanding the current reality; theoretical and methodological positions from which research problems are addressed, ensure that the resulting arguments observe a systemic, useful, truthful and suitable course of which the content started out. This knowledge is focused on general or individual problems that require to be updating or prospecting, either to extend or deepen the epistemic frame of disciplines and sciences –basic research– or to solve specific problems of precise necessity –applied research–, even a branch of this second is known as technological development in Mexico1. In disciplines such as design, research becomes essential to structure appropriately society processes on the current existing hyper technique and mediated civilization. Once the designer lives and recognizes through systemic perception or experience –it means that designer must hold diverse research skills–, therefore it is possible to create a concept from reflection. The deeper or wider this experience is, vaster the concept will be in richness and depth. In other words, a greater amount of conceptualization referents will be developed in terms of objects poiesis and user’s identity references, when the designer has a larger amount of knowledge of life, or particular lives’ contexts.
The culture of water conservation should not only be for the benefit of humans but also for nature, which modifies its structures everyday trying to help humanity. At some point man will pay his stubbornness trying to improve his lifestyle at the expense of the planet. While the water is still contaminated, we must care about its importance not only for men have a sustainable life, but also for other living beings. That is why we should think of efficient use of proper water consumption, through new materials that emulate naturals systems and structures, which make them sustainable, and avoid mixing it with difficult pollutants to remove such as oils, soaps or chemicals pharmaceutical industries (although these ones are due to the lack of importance and seriousness to follow the policies of care and preservation of water). Future generations depend on new ways to obtain and manage water as a resource, but more importantly, it is necessary to reestablish the natural balance with our planet and its resources.
In nature, there are a large number of materials to be discovered, all with different characteristics and for certain functions. In the case of plants, they are responsible for collecting, taking care and protect water naturally. In Mexico there are different plants of the cactus family, which catch and retain water for their existence, so some plants collect more volume of body water than they have. It is very important for this investigation. In Mexico and throughout the continent there is a common cactus or prickly pear that easily adapts to the environment and very rampant in this country, so that its study and analysis makes it one of the most important natural systems for this research, because 95% of it is water and the other 5% is organic material. Later, the common Maguey or agave plant is analyzed, which is important for the history of ancient Mexico, this long before the Spaniards arrived in America. The agave juice and whole plant were an important part of Mexican culture , even today is used in many regions and is an important part of the economy in this country. Last but not least is the barrel cactus plant, which surprisingly lets us see how natural systems build structural and formal elements in order to the creation and configuration of new materials that can significantly help to collect water.
Los yaquis presentan una alta prevalencia de obesidad y la información sobre su dieta es limitada. El objetivo fue diseñar y validar un cuestionario de frecuencia de consumo de alimentos para evaluar la dieta de adultos yaquis (CFCAY). El diseño del CFCAY derivó de la aplicación de dos recordatorios de 24 horas(R24Hrs) en 156 yaquis. La validación del CFCAY vs.R24Hrs para energía total, macronutrientes y micronutrientes se realizó mediante correlación de Pearson (r), de intraclase (CI) y por el gráfico de Bland y Altman (BA). El CFCAY incluyó 123 alimentos, tres tamaños de porción y cinco categorías de frecuencia de consumo. Los coeficientes de r estuvieron entre 0.23 y 0.56, indicando correlaciones aceptables y buenas. Los coeficientes de CI fueron mayores a los de Pearson y el gráfico de BA mostró valores más altos para el CFCAY vs.R24Hrs. El CFCAY permitirá estudiar la dieta de adultos yaquis.
The Yaquis have a high prevalence of obesity and information about their diet is limited. The objective was to design and validate a food consumption frequency questionnaire to evaluate the diet of Yaqui adults (FFQY). The FFQY design derived from the application of two 24 h recalls (24hR) in 156 Yaquis. The validation of FFQY vs. 24hR for totalenergy, macronutrients and micronutrients was performed by Pearson correlation (r), intraclass correlation (IC) and Bland and Altman (BA) graph. The FFQY included 123 foods, three serving sizes and five consumption frequency categories. The coefficients of r were between 0.23 and 0.56, indicating acceptable and good correlations. The IC coefficients were higher than those of Pearson, and the BA graph showed higher values for the FFQY vs. 24hR. The FFQY is a feasible tool to study the diet of Yaqui adults
DAVID MORO FRIAS (2008)
A Current Conveyor (CC) is a minimum 3-terminals device which can perform many useful analog signal processing functions. The first generation CC was introduced in 1969, and more recently, it is a good alternative in Current-Mode design. Nowadays, the CCs can be classified as direct and inverted, and they are divided as first, second and third generation, where they can be positive-type, negative-type, multiple-output and/or current-controlled. In this Thesis it is highlighted that the CC can be easily designed by combining
the connection among di®erent Unity Gain Cells (UGCs) as basic building blocks. Furthermore, from the characteristic equation of each kind of CC, they can be implemented just by superimposing or by cascading UGCs such as voltage (VF) and current followers (CF), and voltage (VM) and current mirrors (CM). New Nullor equivalent representations for all CC topologies are introduced in this work, which are used to perform symbolic analysis of CC-based circuits by applying Nodal Analysis (NA). It is shown that the nullor is a very useful concept that helps the designer to easily analyze analog circuits. In this manner, by using this ideal concept, analytical equations (transfer functions) of CC-based circuits are calculated. The realization of the UGC-based CCs begins by designing each UGC at the transistor level of abstraction. Each UGC has been designed as a symmetrical
type circuit in order to allow superimposing or cascading connection to implement all kinds of CCs, both direct and inverted. Finally, some applications of the UGC-based CCs, like filtering, sinusoidal oscillator and inductance simulator, are presented to show their suitability and usefulness in the field of analog signal processing.
El Current Conveyor (CC) es un dispositivo con un mínimo de tres terminales, el cual puede realizar diversas funciones de procesado analógico de señales. La primera generació de los CC fue presentada en 1969, y recientemente se ha visto como una buena alternativa en el dise~no de circuitos en modo corriente. Los CC pueden ser clasificados como directos o inversos, divididos en primera, segunda y tercera generación, los cuales están subdivididos en positivos, negativos, múltiples salidas y/o controlados por corriente. En el presente trabajo los CC son diseñados combinando diferentes celdas de
ganancia unitaria (UGCs) como bloques básicos de diseño. Tomando la ecuación característica de cada tipo de CC, estos pueden ser implementados superimponiendo estas UGCs, tales como los seguidores de voltaje (VF) y corriente (CF), y espejos de voltaje (VM) y corriente (CM). Se presentan nuevos equivalentes con nullor para todas las topologías de CC, los cuales son usados para realizar un análisis simbólico de circuitos basados en CC aplicando análisis nodal (NA). Se muestra que el nullor es un concepto muy útil que ayuda al diseñador a analizar fácilmente circuitos analógicos. De esta manera, utilizando este concepto ideal, se calculan las funciones de transferencia de varios circuitos basados en los CC. La realización de los CC basados en UGCs comienza dise~nando cada una de es- tas celdas a nivel transistor. Las UGCs fueron diseñadas como circuitos simétricos para poder superimponer cada una de estas celdas para implementar todos los tipos de CC, tanto directos como inversos. Finalmente, algunas aplicaciones de estos CC basados en UGCs son implementados, tales como filtros, osciladores sinusoidales o simuladores de inductancias para demostrar su utilidad en el campo del proceso analógico de señales.
Los requerimientos actuales de productividad industrial exigen que la inspección en línea sea más común en los procesos productivos, lo cual implica altos retos tecnológicos y de innovación para asegurar una medición rápida y precisa. La detección oportuna de defectos ahorra tiempo, energía y materiales en productos defectuosos, también evita el reprocesamiento y favorece el conocimiento del proceso. La integración de nuevas tecnologías, diseños eficaces y métodos de cálculo adecuados, permite la creación de sistemas de inspección en línea robustos, rápidos y precisos. En este trabajo se presenta la aplicación de técnicas numéricas y análisis geométrico en el diseño de un dispositivo para medición en línea de concentricidad en un componente industrial; el método de inspección está basado en la medición del perfil geométrico de la pieza por medio de un sensor electrónico sin contacto, con los datos obtenidos se calcula el centro geométrico con un algoritmo de cálculo basado en la resolución de sistemas de ecuaciones lineales.
Present requirements of productivity in the industry demand a more common on-line inspection in productive processes, which imply high technological and innovation challenges to assure fast and accurate measurement methods. Opportune detection of defects saves time, energy and materials in defective products; also avoid reworks and encourage a better knowledge of the process. The effective integration of new measurement technologies, designs and suitable methods of calculation, allows the creation of robust, fast and accurate on-line inspection systems. In this work, the implementation of numerical techniques and geometrical analysis in the design of a device for the concentricity measurement of an industrial component, is presented; the inspection method is based on the indirect measurement of the geometric profile of the piece with a non-contact electronic sensor, collected data are used to calculate the center of the geometric place through an algorithm based on the resolution of a system of linear equations
Diseño Medición Concentricidad Cálculo Sistemas de ecuaciones no lineales Design Measurement Concentricity Calculation Nonlinear equations system INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA INDUSTRIAL NIVELES ÓPTIMOS DE PRODUCCIÓN