740 research outputs found
Effectiveness and Efficiency of Drug Eluting Stents
Coronary artery disease (CAD), also known as ischemic heart disease (IHD) and coronary
heart disease (CHD), is caused by the narrowing (stenosis) of one or more coronary arteries,
due to atherosclerosis, restricting blood flow and reducing the supply of oxygen to the heart
muscle. Transient shortages in blood flow and oxygen lead to angina pectoris and chest
pain, which may radiate to the left shoulder, arms, neck, back or jaw. Stable angina
symptoms do not tend to progress in intensity over time. More seriously, the rupturing of
an atherosclerotic plaque (causing a thrombotic occlusion) and stenosis of the vessel can
result in acute myocardial infarction (AMI) due to a critical reduction in the blood supply to
the heart muscle (myocardial ischemia). High levels of morbidity and mortality associated
with this infarction are a consequence of ischemia. It is vital to promptly re-establish
coronary blood flow after an infarction, because sustained ischemic damages and injuries to
the heart muscle may lead to sudden death or heart failure. In addition to infarction, acute
symptomatic manifestations of ischemic heart disease include unstable angina, and less
common conditions such as cardiogenic shock and sudden death (Thygesen, 2007)..
Inertial and Degradation Delay Model for CMOS Logic Gates
The authors present the Inertial and Degradation
Delay Model (IDDM) for CMOS digital simulation. The
model combines the Degradation Delay Model presented in
previous papers with a new algorithm to handle the inertial effect,
and is able to take account of the propagation and filtering
of arbitrarily narrow pulses (glitches, etc.). The model clearly
overcomes the limitations of conventional approaches
Mejora en el transporte de material de barro, mediante el desarrollo de una carretilla que reduzca los desperdicios generados
This work solve a real problem that afflicts a certain sector. For this, a field and documentary investigation had to be carried out in the first instance to know the background of the problem and to know what had been done to solve this problem. The manufacture and use of fired bricks dates back to 3500 B.C. this because its consistency was similar to carved stone and because brick was cheaper than this, brick began to replace it as the main construction material. Until a few years ago, the traditional methods of making bricks and tiles continued to be used, which consisted of kneading the clay or earth with the feet when tamping it to create the ideal mud with enough plasticity to be molded, another technique is kneading. the earth by means of a mill pulled by a horse and this process, as well as that of ramming, was slow, although a little more agile than ramming. "Siraly, D. (May 30, 2016)".Este trabajo resolver un problema real que aqueja a un sector determinado. Para esto se tuvo que realizar una investigación tanto de campo como documental en primera instancia para conocer los antecedentes del problema y saber qué es lo que se había hecho para resolver este problema.La fabricación y el uso de ladrillos cocidos se remonta al año 3500 A.C. esto debido a que su consistencia era similar a la piedra tallada y debido a que el ladrillo era más barato que esta, el ladrillo la comenzó a reemplazar como principal material para la construcción. Hasta hace pocos años se seguían utilizando los métodos tradicionales de fabricación de ladrillos y tejas que consistían en amasar la arcilla o tierra con los pies al apisonar esta para crear el lodo que fuera ideal con la suficiente plasticidad para ser moldeado, otra técnica es el amasar la tierra por medio de un molino tirado por un caballo y este proceso al igual que el de pisoneado era tardado, aunque un poco más ágil que de apisonado. “Siraly, D. (30 de mayo de 2016)”
Electrochemical reforming vs. Catalytic reforming of ethanol: A process energy analysis for hydrogen production
This work reports an energetic analysis for hydrogen production via catalytic steam and electrochemical ethanol reforming processes. For both systems, a complete flow diagram process was proposed and simulated by Aspen HYSYS according to literature data. Besides hydrogen, other byproducts such as acetaldehyde (electrochemical reforming) and ethylene and methane (catalytic reforming) were also considered. The energy requirement of the different process units was calculated according to the operating parameters. Just process energy (thermal energy and electrical energy) consumption was considered in the study of the steam reforming whereas both energy process and electrical energy consumption were considered in the study of the electrochemical reforming. Material balances revealed electrochemical reforming to present higher hydrogen yields. (0.0436 vs. 0.0304 kg H2/kg C2H5OH of the classical catalytic reforming). In addition to its higher simplicity, simulation results showed a lower energy consumption in the H2 production by the electrochemical approach (29.2 vs. 32.70 k Wh/Kg of H2). These results demonstrated the interest of the electrochemical reforming of ethanol to obtain high purity hydrogen in a single reaction/separation step, thereby representing an interesting alternative to classical catalytic reforming.Es la versión preprint del artículo. Se puede consultar la versión final en https://doi.org/10.1016/j.cep.2015.05.00
HALOTIS: high accuracy LOgic TIming simulator with inertial and degradation delay model
This communication presents HALOTIS, a novel high
accuracy logic timing simulation tool, that incorporates a
new simulation algorithm based on different concepts for
transitions and events. This new simulation algorithm is
intended for including the inertial and degradation delay
models. Simulation results are very similar to those
obtained by electrical simulators, and show a higher
accuracy compared to conventional delay models
implemented in current logic simulators.Ministerio de Ciencia y Tecnología TIC 2000-135
Degradation Delay Model Extension to CMOS Gates
This contribution extends the Degradation Delay Model (DDM), previously
developed for CMOS inverters, to simple logic gates. A gate-level
approach is followed. At a first stage, all input collisions producing degradation
are studied and classified. Then, an exhaustive model is proposed, which defines
a set of parameters for each particular collision. This way, a full and accurate
description of the degradation effect is obtained (compared to HSPICE) at the
cost of storing a rather high number of parameters. To solve that, a simplified
model is also proposed maintaining similar accuracy but with a reduced number
of parameters and a simplified characterization process. Finally, the complexity
of both models is compared
Gate-Level Simulation of CMOS Circuits Using the IDDM Model
Timing verification of digital CMOS circuits is a
key point in the design process. In this contribution we present
the extension to gates of the Inertial and Degradation Delay
Model for logic timing simulation which is able to take account
of the propagation of arbitrarily narrow pulses. As a result, the
model is ready to be applied to the simulation and verification
of complex circuits. Simulation results show an accuracy similar
to HSPICE and greatly improved precision over conventional
delay models.Ministerio de Ciencia y Tecnología TIC 2000-135
Nuestros mayores activos: inteligentes y emprendedores
This article aims to provide an overview of the capacity of accomplishment of activities that owns the elderly and its relationship with the different intelligences that owns and entrepreneurial skills present in it. The main focus is on analyzing how it affects the continuity of cognitive the onset of old age and the performance of the skills acquired by the elderly in successful aging abilities. From a study of mixed empirical which reflects the results of different personalities that have achieved a high level of success we have analyzed the characteristics of these older adults.El presente artículo pretende dar una visión de la capacidad de logro de actividades que posee el adulto mayor y su relación con las distintas inteligencias que posee y las habilidades emprendedoras presentes en él. El interés fundamental se centra en analizar cómo influye la continuidad de las habilidades cognitivas al inicio de la vejez y el desempeño de las competencias adquiridas por el adulto mayor en el envejecimiento exitoso. A partir de un estudio de tipo empírico mixto donde se reflejan los resultados obtenidos en distintas personalidades relevantes que han alcanzado un nivel alto de éxito se han analizado las características de estos adultos mayores
Emission of neutron–proton and proton–proton pairs in neutrino scattering
We use a recently developed model of relativistic meson-exchange currents to compute the neutron–proton and proton–proton yields in (νμ,μ−) scattering from 12C in the 2p–2h channel. We compute the response functions and cross sections with the relativistic Fermi gas model for different kinematics from intermediate to high momentum transfers. We find a large contribution of neutron–proton configurations in the initial state, as compared to proton–proton pairs. In the case of charge-changing neutrino scattering the 2p–2h cross section of proton–proton emission (i.e., np in the initial state) is much larger than for neutron–proton emission (i.e., two neutrons in the initial state) by a (ω,q)-dependent factor. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-exchange currents, mainly by the Δ isobar current. We also analyze other effects including exchange contributions and the effect of the axial and vector currents.Dirección General de Investigación Científica y Técnica FIS2014-59386-P y FIS2014-53448-C2-1Agencia de Innovación y Desarrollo de Andalucía FQM225 y FQM160Ministerio de Economía y Competitividad IJCI-2014-20038Instituto Nazionale di Fisica Nucleare IS-MANYBODYU.S. Department of Energy DE-FC02-94ER4081
Global Entrepreneurship Monitor. Informe Ejecutivo 2004 Andalucía
El proyecto internacional Global Entrepreneurship Monitor (GEM) nació a finales del siglo XX, de la mano de Babson College y London Business School, para medir de manera homogénea el fenómeno emprendedor en diferentes territorios, facilitando el mayor conocimiento de los procesos de creación de empresas, su comparación y posibilidades de emitir recomendaciones para su impulso y mejora. GEM está organizado en forma de consorcio internacional y asociación sin ánimo de lucro (RED GEM España). GEM ofrece un sistema de información y análisis que permite evaluar la adecuación de las políticas y acciones emprendidas por los gobiernos, centrándose en los procesos de creación de empresas, con una metodología homologada a escala internacional que permite la comparación entre diferentes territorios y países. Una de las claves del reconocimiento internacional del proyecto GEM es la posibilidad de comparación interterritorial, a través de la medición de la actividad emprendedora total en cada territorio analizado. Esta medición y la posibilidad de comparación permiten observar el impacto de las políticas públicas en cada territorio, además de otras variables, sobre la creación de empresas a lo largo del tiempo. Los informes de carácter nacional, en algunos países, como es el caso de España, se complementan y detallan con informes de ámbito regional que permite decisiones más cercana a la diversidad territorial. La aplicación de una metodología común para todos los países y regiones asegura la comparación de los resultados de cada estudio territorial. El diseño de la investigación favorece la obtención de una serie de indicadores homogéneos para cada país o región participante, que garantizan la validez y el sentido de la comparación. Las fuentes de información que GEM emplea para la realización de los informes son tres: (1) una encuesta a la población adulta (de 18 a 64 años de edad) de cada país y territorio, para detectar las características específicas de los emprendedores y los condicionantes específicos de la creación de empresas; (2) un cuestionario dirigido a un panel de expertos, que permite obtener una opinión cualificada y diversa sobre el fenómeno emprendedor; y (3) un conjunto de variables secundarias, económicas y sociales, obtenidas de fuentes contrastadas a escala internacional. La información recabada a través de estas tres fuentes, que se completan y complementan, se trata y elabora como base para la realización de los distintos apartados que integran el informe. Para más información consúltese: https://www.gemconsortium.org
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