361 research outputs found
Entrevistas a ingenieros egresados de la Facultad de Ingeniería
No full textEn esta sección muestran dos entrevistas a ingenieros egresados de la Facultad de Ingeniería. En primer lugar los ingenieros Marcelo Riveros y Alberto Mayor realizan una entrevista a la ilustre Ingeniera Guillermina Uribe, quien fue la primera mujer graduada en la Facultad de Ingeniería de la Universidad Nacional de Colombia. Por otro lado, los ingenieros Antonio Mejía y Alberto Mayor entrevistan al ingeniero José Fernando Isaza, egresado de la Facultad de Ingeniería de la Universidad Nacional de Colombia. Estas entrevistas representan el trabajo de hombres y mujeres ilustres en el desarrollo de la Ingeniería en Colombia
¿Un nuevo mundo rural y agroindustrial post-COVID-19?: Mesa 3
No full textHernando Riveros, Consultor internacional- Perú | Marvin Blanco, IICA-Costa Rica | Marcelo Champredonde, RedSIAL-ArgentinaLos invitamos a reflexionar sobre los cambios en el medio rural y Agroindustrial que vendrán después de la pandemia. Participa en nuestro coloquio a distancia.
IICA, UAEMex, Red Sial México y Red Sial Americana invitan
Juan Pablo Riveros: coherencia de un proyecto poético.
No full textWithin the framework of the development of Chilean literary activity, mainly in the area of the southern city of Concepción, the paper offers a view of the poetic works of Juan Pablo Riveros: De la tierra sin fuegos, Libro del frío, and Poema del cosmos. These works are characterized by a deep internal cultural coherence, because the author has elaborated them through a process of extended study, where elements of scientific development interact with a lucid understanding of the poetic fact.En el marco del desarrollo de la actividad literaria chilena, y específicamente de Concepción, se ofrece un panorama de la obra poética de Juan Pablo Riveros. Se examinan sus tres libros mayores: De la tierra sin fuegos, Libro del frío y Poema del cosmos. Estas obras muestran una gran coherencia entre sí, porque el autor las elabora en un proceso de largo estudio, donde nociones provenientes del desarrollo científico se aúnan a una lúcida comprensión del hecho poético
The impact of labor costs on manufactured exports in developing countries : an econometric analysis
No full textThis paper estimates export supply elasticities in 20 countries using an empirical model in which manufactured exports are a function of the price of exports, the price of imported inputs, and labor costs relative to the price of home goods. The export supply equation is completed with a variable identifying manufacturing capacity and a variable associated with the role of internal absorption. After testing for simultaneity, the paper concludes that half of the countries must be treated as large countries - thus estimating the export supply function through two-stage least squares. Also explored are other sources of endogeneity of right-hand side variables - the price of imported inputs, labor costs, and manufacturing capacity. It is found that in many cases the estimates change significantly as a result of this procedure. In general, the conclusions underscore the impact on exports of domestic economic policies - for example, promoting investment and productive capacity and keeping factor markets free of significant distortions.Economic Theory&Research,Environmental Economics&Policies,Access to Markets,Markets and Market Access,Banks&Banking Reform
Propuesta de mejoramiento de la gestión pedagógica del equipo de gestión mediante el desarrollo de un plan de acompañamiento profesional en el Liceo Almirante Galvarino Riveros de la comuna de Conchalí
No full textTesis (Magíster en Desarrollo Curricular y Proyectos Educativos)El presente seminario de grado desarrolla una propuesta de mejoramiento para fortalecer las
competencias de los integrantes del equipo de gestión del Liceo Almirante Galvarino Riveros de
la comuna de Conchalí.
La labor de los líderes escolares se puede resumir en la capacidad que tienen para influenciar a los
profesores para que mejoren sus prácticas y a su vez impacten positivamente en las trayectorias
escolares de niños, niñas y jóvenes. En este contexto, la propuesta de mejoramiento que se expone
en las siguientes páginas está enmarcada en la presentación de una propuesta de mejoramiento
escolar, orientada a la confección de un plan de trabajo, basado en la observación y
retroalimentación de las prácticas docentes, liderado por el equipo de gestión. El objetivo es
mejorar la práctica docente a través de una propuesta de mejoramiento basada en la instalación de
un proceso de acompañamiento docente por parte de equipo de gestión de Liceo Almirante
Galvarino Riveros.
El plan de trabajo está antecedido por la caracterización de la comunidad del Liceo Almirante
Galvarino Riveros, la identificación y justificación de la problemática y sustentado en un marco
conceptual que aborda los principales componentes del liderazgo educativo y la observación y
retroalimentación de clases.
Esta propuesta permitirá dotar a la comunidad profesional de un plan sistematizado, con
instrumentos confeccionados de manera colaborativa, fomentar la reflexión profesional sobre los
procesos que protagonizan profesores y estudiantes y fortalecer el rol del equipo de gestión en el
acompañamiento a los docentes
Descriptive Complexity for Counting Complexity Classes
No full textDescriptive Complexity has been very successful in characterizing complexity
classes of decision problems in terms of the properties definable in some
logics. However, descriptive complexity for counting complexity classes, such
as FP and #P, has not been systematically studied, and it is not as developed
as its decision counterpart. In this paper, we propose a framework based on
Weighted Logics to address this issue. Specifically, by focusing on the natural
numbers we obtain a logic called Quantitative Second Order Logics (QSO), and
show how some of its fragments can be used to capture fundamental counting
complexity classes such as FP, #P and FPSPACE, among others. We also use QSO to
define a hierarchy inside #P, identifying counting complexity classes with good
closure and approximation properties, and which admit natural complete
problems. Finally, we add recursion to QSO, and show how this extension
naturally captures lower counting complexity classes such as #L
International differences in wage and nonwage labor costs
No full textThe ratio of nonwage labor costs (for social security, pensions, vacation days, severence compensation, and the like) to direct wage costs is proportionately higher in Europe and Latin America than in Asia and Africa - largely because workers there are protected more by regulations. The distortionary growth of labor costs because of increasing nonwage costs is not common in the LDCs however. The author of this paper found that international differences in labor costs are attributable largely to differences in labor productivity and capital-labor ratios. The author also found that labor costs declined significantly in almost all LDCs in the 1980s, and that the impact of declining labor costs on manufacturing employment was statistically significant - and bodes well for the growth of nontraditional exports. International differences in labor cost levels are important, especially when one compares LDC and industrial economies. But differences between labor cost levels in terms of per capita output are not so large. This suggests the importance of different capital-labor ratios.Labor Markets,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Municipal Financial Management
Departamento de Ingenieria Química: treinta años de realizaciones
No full textEste artículo presenta una descripción historica del Departamento de Ingeniería Química en sus primeros 30 año
Asymmetric biphasic hydrophobic/hydrophilic poly(Lactic acid)–polyvinyl alcohol meshes with moisture control and noncytotoxic effects for wound dressing applications
No full textA noncytotoxic film was developed in this work with asymmetric biphasic properties (hydrophilic/hydrophobic) that allow for gas exchange. Among its many biomedical applications, it could be applied as a wound dressing material where the absorption of exuded fluids and control of water loss is required simultaneously. Thin meshes were developed modifying one face of poly(lactic acid) (PLA) electrospun mats with polyvinyl alcohol (PVA) using a simple photografting methodology. The contact angle of the modified face of the film was 44 while that of the other face was the original value of 122 . The chemical modification was covalent, as confirmed by X-ray photoelectron spectroscopy, stable over time and resistant to successive washing steps. Cytotoxic assays with fibroblast cells showed that PVA photo-grafted onto PLA meshes present a high cell viability percentage.Fil: Ribba, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Tamayo, Laura. Universidad de Chile; ChileFil: Flores, Marcos. Universidad de Chile; ChileFil: Riveros, Ana. Universidad de Chile; ChileFil: Kogan, Marcelo Javier. Universidad de Chile; ChileFil: Cerda, Enrique. Universidad de Santiago de Chile; ChileFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin
Unimolecular dissociation induced by thermal radiation
No full textProcessos de fragmentação são ferramentas fundamentais no estudo de íons por espectrometria de massas, pois permitem a obtenção de informação sobre a estrutura e termoquímica destes íons . Desenvolvemos uma técnica de dissociação de íons baseada na ativação destes através da absorção multifotônica sequencial de radiação infravermelha de um filamento incandescente. Nesta técnica, íons aprisionados na cela de um espectrômetro de massas por transformada de Fourier são submetidos a radiação do filamento por intervalos de tempo relativamente longos (da ordem de segundos), e passam por um processo de multíplos eventos de absorção e emissão de radiação, até a energia interna dos íons atingir um nível suficiente para a fragmentação. A partir deste modelo para o processo foram implementados métodos computacionais que permitem a simulação da dissociação. A realização destas simulações exige o conhecimento do espectro vibracional do íon, que normalmente tem que ser obtido por algum método teórico de cálculo, como foi feito neste trabalho paro o caso de alguns dos íons estudados. O método de dissociação unimolecular induzida por absorção de radiação infravermelha foi aplicado na determinação das energias de ativação e de dissociação dos íons moleculares de acetofenona, p-cimeno e cumeno. Este método também mostrou-se capaz de diferenciar diferentes estruturas isomericas, e foi com esta finalidade aplicado no estudo da isomerização ceto-enol do íon molecular de acetofenona. Demonstrou-se também a capacidade do método dissociar os íons moleculares de n-butilbenzeno e brometo de alila.Fragmentation processes are fundamental tools for the mass spectrometric study of ions because they provide information on structure and termochemistry of these ions. We have developed a dissociation technique that is based on the multiphoton activation of trapped ions by infrared radiation emitted by an incandescent filament. In this technique, ions trapped in the cell of a Fourier Transform mass spectrometer are exposed to the filament radiation for long time periods (seconds), and a process of multiple absorption and emition events occurs, until the internal energy of the ions is high enough for fragmentation. Computational methods have been implemented from this model allowing for simulation of the dissociation process. For this simulation the ion vibrational spectra, that normally must be obtained from theoretical calculations, is also required, as has been done in this work for some of the studied ions. The method of unimolecular dissociation induced by infrared radiation was applied to the determination of activation and dissociation energies of the molecular ions of acetophenone, p-cymene and cumene. This method also proved to be capable in the differentiation of isomeric structures, and was so applied in the study for the keto-enol isomerization of the acetophenone molecular ion. It was also shown that the method can dissociate the molecular ions of n-butylbenzene an allyl bromide
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