Convection in a rectangular channel with a flow of water in laminar-turbulent transition with high heat fluxes

In this work we examine the phenomenon of laminar-turbulent transition in a heated rectangular channel under high heat fluxes and water as a working fluid. We use an experimental device that allows the electric heating of the walls and the measurement of its temperature through thermocouples housed beneath the surface. The results of this initial exploration clearly show the dependence of the convection coefficient on the heat flux through different mechanisms. In first place we can see an increase in the convection coefficient with the heat flux that is correctly predicted for laminar and turbulent flows by the Sieder-Tate correction. In second place, there was a clear change of behaviour that corresponds to the start of the transition to turbulence. The Reynolds number that corresponds to the departure from laminar behavior was independent of the heat flux in the walls within the conditions covered in this study.Fil: Silin, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Masson, Viviana Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; Argentina. Comision Nacional de Energia Atomica. Gerencia del Area de Investigaciones y Aplicaciones no Nucleares. Gerencia de Fisica (CAB); ArgentinaFil: Garcia, J. C.. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; Argentina. Comision Nacional de Energia Atomica. Gerencia del Area de Investigaciones y Aplicaciones no Nucleares. Gerencia de Fisica (CAB); Argentin

Validación con datos in-situ de alturas de ola obtenidas mediante radar altimétrico

Los rádares altimétricos a bordo de satélites artificiales, han sido diseñados para dar información precisa de la altura del nivel del mar, la altura de ola significante y la velocidad del viento sobre la superficie del mar. En los estudios, tanto anteriores como actuales, se observan problemas en las regiones costeras, donde las medidas del altímetro tienen menor precisión y una mayor dificultad a la hora de interpretar estos datos. Estos inconvenientes son debidos a dos factores principales. En primer lugar, la contaminación de la señal radar debido a la cercanía de la costa. En segundo lugar, inexactitudes en las correcciones de marea y troposférica húmeda. A estos problemas se añade la complejidad de la zona de estudio, al ser una región con una amplia gama de procesos hidrodinámicos con diversas escalas espacio-temporales. Tener acceso a información exacta en la costa, con las condiciones que conlleva, tiene una gran importancia debido al enorme interés económico-estratégico de la zona litoral. Este interés hace que surjan nuevas estrategias para generar productos altimétricos optimizados para tales condiciones. Las medidas de la altura de ola significante y su variabilidad en las áreas costeras son usadas para muchos propósitos (por ejemplo, análisis del transporte de sedimento, setup de la ola y tormentas de marea), y para la validación/calibración de modelos (pronóstico de oleaje, circulación oceánica). Estas aplicaciones sirven para un amplio rango de propósitos sociales relevantes, tales como el diseño de estructuras de ingeniería en alta mar, la protección de las zonas costeras, rutas para los buques y la planificación de las operaciones en el océano. Muchos estudios se han dedicado a la validación de los datos de la altura de ola significante dados por el radar altimétrico a bordo de satélites artificiales, utilizando observaciones in-situ. El objetivo de esta ponencia es exponer una metodología para validar los datos de altura de oleaje proporcionados por el radar altimétrico RA-2 a bordo del satélite ENVISAT, a partir de datos in-situ medidos por una boya, y su aplicación a un caso particular

Meconium in the Amniotic Fluid of Pregnancies Complicated by Preterm Premature Rupture of Membranes Is Associated With Early Onset Neonatal Sepsis

Objective: This study was to determine the significance of meconium in the amniotic fluid of pregnancies complicated by preterm premature rupture of membranes (PPROM) without labor

Role of Peroxisome Proliferator-Activated Receptor Gamma and Its Ligands in the Treatment of Hematological Malignancies

Peroxisome proliferator-activated receptor gamma (PPARγ) is a multifunctional transcription factor with important regulatory roles in inflammation, cellular growth, differentiation, and apoptosis. PPARγ is expressed in a variety of immune cells as well as in numerous leukemias and lymphomas. Here, we review recent studies that provide new insights into the mechanisms by which PPARγ ligands influence hematological malignant cell growth, differentiation, and survival. Understanding the diverse properties of PPARγ ligands is crucial for the development of new therapeutic approaches for hematological malignancies

Effects of mergers and galaxy interactions at intermediate densities in the SDSS-DR4

Recently, several observational works have provided evidence in favor of a pre-processing of galaxies at moderate environments. These evidences show that the transition of galaxies onto the red-sequence could take place in galaxy groups in the outskirt of clusters or in the infalling populations. Based on the evidence that interacting and merging systems are priviledged found at intermediate densities, we use the SDSSDR4 data to analyse the role of mergers and close galaxy interactions as environmental processes to lead to evolutionary transformations. We explore the properties of galaxy pairs and merging systems at different local and global density environments, comparing them with those of isolated galaxies in an unbiased control sample.Recientemente varios autores han aportado evidencia observacional que sugerir´ıa que las galaxias son pre-procesadas en regiones de densidad intermedia, produciendo una gran transformacion en las mismas. Estos resultados observacionales muestran que la transicion de las galaxias hacia la secuencia roja se producir´ıa en regiones perifericas de los cumulos de galaxias. Por otra parte, existe evidencia tanto teorica como observacional que indicar´ıa que las interacciones y fusiones de galaxias son particularmente frecuentes en estas regiones. En este trabajo analizamos el rol de las interacciones y colisiones de galaxias en regiones de densidad intermedia, utilizando para tal efecto galaxias del cat´alogo SDSS-DR4.Fil: Perez, J.. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Tissera, Patricia Beatriz. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Padilla, N.. Pontificia Universidad Católica de Chile; ChileFil: Alonso, S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "el Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "el Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "el Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "el Leoncito"; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomia Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomia Teórica y Experimental; Argentin

Near-neighbor mixing and bond dilation in mechanically alloyed Cu-Fe

Extended x-ray-absorption fine-structure (EXAFS) measurements were used to obtain element- specific, structural, and chemical information of the local environments around Cu and Fe atoms in high-energy ballmilled Cu_Fe_(12-X) samples (x=0.50 and 0.70). Analysis of the EXAFS data shows both Fe and Cu atoms reside in face-centered-cubic sites where the first coordination sphere consists of a mixture of Fe and Cu atoms in a ratio which reflects the as-Prepared stoichiometry. The measured bond distances indicate a dilation in the bonds between unlike neighbors which accounts for the lattice expansion measured by x-ray diffraction. These results indicate that metastable alloys having a positive heat of mixing can be prepared via the high-energy ballmilling process

Mechanically driven alloying of immiscible elements (Comment)

In conclusion we have proven that the fact that both fcc FeCu and bcc Fe magnetization agree at 300 K is simply an accident and our data at low temperature show clearly that the Fe contribution after precipitation from the metastable phase has a deficiency in magnetization of at least 20% with respect to the Fe state in fcc FeCu metastable solid solution

Strengthening Mentoring in Low- and Middle-Income Countries to Advance Global Health Research: An Overview.

Mentoring is a proven path to scientific progress, but it is not a common practice in low- and middle-income countries (LMICs). Existing mentoring approaches and guidelines are geared toward high-income country settings, without considering in detail the differences in resources, culture, and structure of research systems of LMICs. To address this gap, we conducted five Mentoring-the-Mentor workshops in Africa, South America, and Asia, which aimed at strengthening the capacity for evidence-based, LMIC-specific institutional mentoring programs globally. The outcomes of the workshops and two follow-up working meetings are presented in this special edition of the American Journal of Tropical Medicine and Hygiene. Seven articles offer recommendations on how to tailor mentoring to the context and culture of LMICs, and provide guidance on how to implement mentoring programs. This introductory article provides both a prelude and executive summary to the seven articles, describing the motivation, cultural context and relevant background, and presenting key findings, conclusions, and recommendations

Computer Networks Virtualization with GNS3: Evaluating a solution to optimize resources and achieve a distance learning

Designing educational resources allow students to modify their learning process. In particular, on-line and downloadable educational resources have been successfully used in engineering education the last years [1]. Usually, these resources are free and accessible from web. In addition, they are designed and developed by lecturers and used by their students. But, they are rarely developed by students in order to be used by other students. In this work-in-progress, lecturers and students are working together to implement educational resources, which can be used by students to improve the learning process of computer networks subject in engineering studies. In particular, network topologies to model LAN (Local Area Network) and MAN (Metropolitan Area Network) are virtualized in order to simulate the behavior of the links and nodes when they are interconnected with different physical and logical design.This work is supported by the “Computer Science Research Institute” of the University of Alicante through the aid “Internationalization and quality of the doctoral program”