7,322 research outputs found
Microminiature thermocouple monitors own installation
Microminiature thermocouple makes precision gas sidewall temperature readings inside large thrust chambers. It is installed by a technique whereby the sensor monitors its own installation to insure against thermal damage to the thermocouple and ensure minimum disturbance to chamber surfaces
Supporting Tropos concepts in Agent OPEN
The growth of interest in agent-orientation as a new paradigm has introduced the need for developing concepts, tools and techniques for modeling and engineering agent-based software systems. Object technology has been supporting the development of information systems for many years but is now slowly evolving to encompass more recent ideas relating to the concept of "agent". Integrating agent concepts into existing OO methodologies has resulted in several agent-oriented methodologies, one of which is Agent OPEN. In this paper, we evaluate the existing Agent OPEN description against ideas formulated within Tropos, an agent-oriented software development methodology. © Springer-Verlag Berlin Heidelberg 2004
On the design of an interactive biosphere for the GLAS general circulation model
Improving the realism and accuracy of the GLAS general circulation model (by adding an interactive biosphere that will simulate the transfers of latent and sensible heat from land surface to atmosphere as functions of the atmospheric conditions and the morphology and physiology of the vegetation) is proposed
The Smallest Molecular Switch
Ab-initio total energy calculations reveal benzene-dithiolate (BDT) molecules
on a gold surface, contacted by a monoatomic gold STM tip to have two classes
of low energy conformations with differing symmetries. Lateral motion of the
tip or excitation of the molecule cause it to change from one conformation
class to the other and to switch between a strongly and a weakly conducting
state. Thus, surprisingly, despite their apparent simplicity these Au/BDT/Au
nanowires are shown to be electrically bi-stable switches, the smallest
two-terminal molecular switches to date. Experiments with a conventional or
novel self-assembled STM are proposed to test these predictions.Comment: 8 pages, 3 figure
Comparison of the Interactions of Transferrin Receptor and Transferrin Receptor 2 with Transferrin and the Hereditary Hemochromatosis Protein HFE
The transferrin receptor (TfR) interacts with two proteins important for iron metabolism, transferrin (Tf) and HFE, the protein mutated in hereditary hemochromatosis. A second receptor for Tf, TfR2, was recently identified and found to be functional for iron uptake in transfected cells (Kawabata, H., Germain, R. S., Vuong, P. T., Nakamaki, T., Said, J. W., and Koeffler, H. P. (2000) J. Biol. Chem. 275, 16618-16625). TfR2 has a pattern of expression and regulation that is distinct from TfR, and mutations in TfR2 have been recognized as the cause of a non-HFE linked form of hemochromatosis (Camaschella, C., Roetto, A., Cali, A., De Gobbi, M., Garozzo, G., Carella, M., Majorano, N., Totaro, A., and Gasparini, P. (2000) Nat. Genet. 25, 14-15). To investigate the relationship between TfR, TfR2, Tf, and HFE, we performed a series of binding experiments using soluble forms of these proteins. We find no detectable binding between TfR2 and HFE by co-immunoprecipitation or using a surface plasmon resonance-based assay. The affinity of TfR2 for iron-loaded Tf was determined to be 27 nM, 25-fold lower than the affinity of TfR for Tf. These results imply that HFE regulates Tf-mediated iron uptake only from the classical TfR and that TfR2 does not compete for HFE binding in cells expressing both forms of TfR
Desarrollo, implementación y publicación de un sistema geográfico para la gestión vial del cantón Cuenca
En la ciudad de Cuenca, el aumento del parque automotor conlleva un problema de congestión vehicular, a esto contribuye el cierre de vías por mejoras en la ciudad, estas circunstancias han provocado un malestar en los usuarios de sistemas públicos y privados de transporte, agravando el estrés urbano como consecuencia de la contaminación, el aumento de los tiempos de viaje,repercutiendo de forma económica y social en la población de Cuenca. Disponer de mapas y cartografía vial accesible desde dispositivos móviles como celulares, GPS, tablets, PDA, permite tener alternativas de circulación y brinda herramientas para generar rutas alternas para llegar a un destino.
Una propuesta de gran acogida es la iniciativa Openstreetmap, la cual busca generar mapas viales del mundo a través de aportes hechos por usuarios entusiastas que usan las capturas de datos de GPS en el terreno, para luego ingresarla a la web. Algo similar se ha puesto en funcionamiento en la plataforma de la Universidad del Azuay con la información cartográfica vial actualizada y depurada a nivel 2, lo que representa vías principales y secundarias en diferentes formatos para su descarga. Este sitio también tiene accesos a los diferentes portales que disponen de información cartográfica vial
Strong light-matter coupling in bulk GaN-microcavities with double dielectric mirrors fabricated by two different methods
Two routes for the fabrication of bulk GaN microcavities embedded between two dielectric mirrors are described, and the optical properties of the microcavities thus obtained are compared. In both cases, the GaN active layer is grown by molecular beam epitaxy on (111) Si, allowing use of selective etching to remove the substrate. In the first case, a three period Al0.2Ga0.8N / AlN Bragg mirror followed by a lambda/2 GaN cavity are grown directly on the Si. In the second case, a crack-free 2,mu m thick GaN layer is grown, and progressively thinned to a final thickness of lambda. Both devices work in the strong coupling regime at low temperature, as evidenced by angle-dependent reflectivity or transmission experiments. However, strong light-matter coupling in emission at room temperature is observed only for the second one. This is related to the poor optoelectronic quality of the active layer of the first device, due to its growth only 250 nm above the Si substrate and its related high defect density. The reflectivity spectra of the microcavities are well accounted for by using transfer matrix calculations. (C) 2010 American Institute of Physics. [doi:10.1063/1.3477450
Reynolds-Averaged Navier-Stokes Analysis of Zero Efflux Flow Control over a Hump Model
The unsteady flow over a hump model with zero efflux oscillatory flow control is modeled computationally using the unsteady Reynolds-averaged Navier-Stokes equations. Three different turbulence models produce similar results, and do a reasonably good job predicting the general character of the unsteady surface pressure coefficients during the forced cycle. However, the turbulent shear stresses are underpredicted in magnitude inside the separation bubble, and the computed results predict too large a (mean) separation bubble compared with experiment. These missed predictions are consistent with earlier steady-state results using no-flow-control and steady suction, from a 2004 CFD validation workshop for synthetic jets
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