Combustion characteristics in the transition region of liquid fuel sprays

A number of important effects have been observed in the droplet size transition region in spray combustion systems. In this region, where the mechanism of flame propagation is transformed from diffusive to premixed dominated combustion, the following effects have been observed: (1) maxima in burning velocity; (2) extension of flammability limits; (3) minima in ignition energy; and (4) minima in NOx formation. A monodisperse aerosol generator has been used to form and deliver a well controlled liquid fuel spray to the combustion test section where measurements of ignition energy have been made. The ignition studies were performed on monodisperse n-heptane sprays at atmospheric pressure over a range of equivalence ratios and droplet diameters. A capacitive discharge spark ignition system was used as the ignition source, providing independent control of spark energy and duration. Preliminary measurements were made to optimize spark duration and spark gap, optimum conditions being those at which the maximum frequency or probability of ignition was observed. Using the optimum electrode spacing and spark duration, the frequency of ignition was determined as a function of spark energy for three overall equivalence ratios (0.6, 0.8, and 1.0) and for initial droplet diameters of 25, 40, 50, 60, and 70 micro m

Combustion characteristics in the transition region of liquid fuel sprays

A number of important effects were observed in the droplet size transition region in spray combustion systems. In this region, where the mechanism of flame propagation is transformed from diffusive to premixed dominated combustion, the following effects have been observed: (1) maxima in burning velocity; (2) extension of flammability limits; (3) minima in ignition energy; and (4) minima in NO(x) formation. Unfortunately, because of differences in experimental facilities and limitations in the ranges of experimental data, a unified description of these transition region effects is not available at this time. Consequently, a fundamental experimental investigation was initiated to study the effect of droplet size, size distribution, and operating parameters on these transition region phenomena in a single well controlled spray combustion facility

Donkey Milk Proteins: Digestibility and Nutritional Significance

Donkey milk is particularly recommended for infant nutrition as substitute of cow milk in case of sensitive neonates (showing cow milk protein allergies). Its protein composition and the ratio between caseins and whey proteins reveals a high similarity with human milk, thus, in the last 10 years, an increasing interest arose to obtain a full characterisation of donkey milk proteins, here acknowledged. Digestibility data, mainly derived in vitro with human gastrointestinal enzymes, showed the high digestibility of donkey caseins and major whey proteins, except lysozyme and α-lactalbumin which proved to be quite resistant. The reported antimicrobial properties of donkey milk open concrete possibilities to use donkey milk as natural food preservative. Due to its attractive healthy properties, donkey milk was investigated for useful applications or to develop novel foods characterised by a high nutritional profile

Dairy buffalo life cycle assessment (LCA) affected by a management choice: the production of wheat crop

Life cycle assessment (LCA) was performed in dairy buffalo farms representative of Southern Italian farming systems, similar due to several characteristics, with the exception of wheat production. This work evaluated the impacts derived from this management choice, comparing farms with wheat crop (WWC) or not (NWC). In agreement with the literature, economic allocation was chosen as a useful strategy to attribute equivalents to by-products, i.e., culled animals; the same criterion was also adopted to assign pollutants to wheat grain, limited to WWC farms. Environmental impacts in terms of Global Warming Potential (GWP, kg CO2 eq), Acidification Potential (AC, g SO2 eq), Eutrophication Potential (EU, g PO43- eq), Agricultural Land Occupation (ALO, m2 y) and Water Depletion (WD, m3) were estimated. The production of wheat crop significantly affected (p < 0.05) the Agricultural Land Occupation (ALO) category as WWC farms need adequate land. WWC farms could allow a significant reduction in eutrophication (EU) compared to NWC farms (p < 0.05)

Isolation and Molecular Characterization of a Novel Cytopathogenic Paramyxovirus from Tree Shrews

AbstractA cytopathic infectious agent was isolated from the kidneys of an apparently healthy tree shrew (Tupaia belangeri) that had been captured in the area around Bangkok. The infectivity was propagated in Tupaia fibroblast and kidney cell cultures. Paramyxovirus-like pleomorphic enveloped particles and helical nucleocapsids were observed by electron microscopy and accordingly the infectious agent was termed Tupaia paramyxovirus (TPMV). However, no serological cross-reactions were detected between TPMV and known paramyxoviruses. For the molecular characterization of TPMV an experimental strategy that allows the random-primed synthesis of relatively large cDNA molecules from viral genomic RNA was applied. Nucleotide sequence analysis of a TPMV-specific cDNA fragment (1544 bp) revealed two nonoverlapping partial open reading frames corresponding to paramyxoviral N and P transcription units. Using modified rapid amplification of cDNA ends techniques, a substantial contiguous portion of the viral genome (4065 nt) was elucidated including the complete N and P/V/C genes. The coding strategy of TPMV as well as significant amino acid sequence homologies clearly indicates an evolutionary relationship between TPMV and members of the genus Morbillivirus. Highest homologies were detected between TPMV and Hendra virus (equine morbillivirus), which recently emerged in Australia, causing outbreaks of fatal respiratory and neurological disease in horses and humans

Bioactive peptides in dairy products

Bioactive peptides are specific protein fragments that have a positive impact on body functions and conditions and may ultimately influence health. Most of the biological activities are encrypted within the primary sequence of the native protein and can be released by enzymatic hydrolysis and proteolysis or by food processing. Milk is a rich source of bioactive peptides which may contribute to regulate the nervous, gastrointestinal and cardiovascular systems as well as the immune system, confirming the added value of dairy products that, in certain cases, can be considered functional foods. The main biological activities of these peptides and their bioavailability in dairy products are reviewed. The natural concentration of these biomolecules is quite low and, to date one of the main goals has been to realize products enriched with bioactive peptides that have beneficial effects on human health and proven safety. Even though several health-enhancing products have already been launched and their integration in the diet could help in the prevention of chronic diseases such as hypertension, cancer and osteoporosis, more clinical trials are required in order to develop a deeper understanding of the activity of biopeptides on the human physiological mechanisms and also to assess the efficacy of their effects in a long term view. New scientific data are also needed to support their commercialisation in compliance with current regulations

Sistemas embebidos y de tiempo real con planificación heterogénea

Este proyecto plantea, como objetivo general, el desarrollo de técnicas de modelado, diseño, análisis, optimización y prueba de Sistemas Embebidos con requerimientos de Tiempo Real, específicamente del tipo Heterogéneo, sobre diferentes plataformas hardware y software. El objetivo es lograr un balance apropiado de prestaciones, rendimiento y eficiencia en el desarrollo de nuevos sistemas.Eje: Procesamiento de Señales y Sistemas de Tiempo.Red de Universidades con Carreras en Informátic

Bluebot: una propuesta accesible de robótica móvil para propósitos didácticos

La robótica es un tema de importancia central para el desarrollo científico y tecnológico, y sus aplicaciones industriales son innumerables. Por otra parte, el uso de robots como medio didáctico es una alternativa significativa como motivación para materias introductorias y avanzadas en carreras de Informática e Ingeniería Electrónica, y sirve como eje de integración horizontal y vertical de contenidos curriculares. La robótica móvil es uno de los campos de investigación que mayor auge está teniendo como investigación aplicada. Dentro de este campo consideramos específicamente a los robots móviles teleoperados, que son aquellos cuyos movimientos son comandados a distancia. Estos robots, de uso industrial y militar son usados para ejecutar tareas peligrosas o para acceder a lugares de difícil acceso para los seres humanos (desactivación de bombas, exploraciones submarinas, el interior de centrales nucleares, etc.) Son plataformas de alto costo, imposibles de ser consideradas para una aplicación didáctica. Este proyecto consiste en el desarrollo de un robot didáctico bluebot, con tecnología sencilla y al alcance de las capacidades de una escuela, centro educativo o universidad de recursos limitados. El proyecto incluye la construcción de un robot (hardware) y del soporte informático (software) que permita su manejo por usuarios sin experiencia o formación específica. Mediante técnicas de enseñanza experimental el alumno inicial aprende nociones formales de algoritmo, secuencia y ejecución de autómatas. Para el alumno avanzado de ingeniería y de las carreras de informática el robot proporciona la posibilidad de experimentar en forma práctica con conceptos avanzados como las vistas en las materias de informática teórica y de control automático. El robot se telecomanda desde una computadora personal y en un futuro se incorporará un sistema de sensado de posición y de velocidad basado en la captura de imágenes provenientes de una cámara digital de bajo costo (tipo webcam). El alumno proporciona instrucciones en un lenguaje que inicialmente se ha diseñado de bajo nivel aunque se contempla el desarrollo de una gramática libre de contexto de alto nivel en desarrollos futuros. Uno de los principales objetivos de este proyecto es formar desarrolladores con la capacidad y experiencia para poder definir nuevos sistemas, productos y mercados que utilicen esta tecnología. Existe en el país un gran potencial para desarrollos en rob´otica, tanto en el contexto industrial como en aplicaciones para la gestión del medio ambiente, por lo que se espera un alto grado de transferencia tecnológica como producto colateral de la formación que puede darse a través de estas experiencias teóricas y prácticas. Un proyecto de estas características, dado el atractivo social que genera el uso de la tecnología y el muy bajo costo de la misma, es ideal para ser promocionado en colegios y otras instituciones educativas, para fomentar el interés en los estudios universitarios. Ello conseguirá atraer más y mejores alumnos a las carreras técnicas de la universidad patrocinadora, actuando sobre una de las posibles razones por la merma de inscripción registrado en los recientes años. Por otra parte, el uso de esta tecnología como herramienta de estudio en las materias de las carreras de informática permitirá motivar a los alumnos de las mismas para participar en las asignaturas y así disminuir el índice de deserción, minimizar el tiempo de finalizado de la carrera, y extender las experiencias más allá de lo meramente formal. El desarrollo es lo suficientemente genérico como para que puedan participar alumnos de diferentes carreras, y diferentes niveles dentro de las mismas, favoreciendo la aplicación de los contenidos de cada materia en la solución de problemas concretos. Esto permite abordar un tema de gran importancia para la formación profesional, como es la integración curricular horizontal y vertical de los contenidos de varias asignaturas, lo cual hace posible que los alumnos comprendan el alcance y utilidad de los diferentes bloques curriculares y mejoren conceptualmente su articulación.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI