15,877 research outputs found
Earthen construction: structural vulnerabilities and retrofit solutions for seismic actions
Earthen structures present very appealing characteristics regarding a more sustainable practice with the
preservation of our natural resources. However, when subjected to earthquake ground motions, this type of
construction may present a deficient performance, which may cause significant human losses and important
structural damage. The seismic response of earthen structures is typically characterized by fragile failures. There
are several examples of recent earthquakes that affected earthen buildings in a severe way, evidencing the
vulnerability of this type of construction, like the El Salvador earthquake, in 2001, the Bam, Iran earthquake, in
2003, the Pisco, Peru earthquake, in 2007 and the Maule, Chile earthquake, in 2010.
The construction of earth structures on earthquake-prone areas must be carefully studied and should include
seismic reinforcement solutions in order to improve their seismic performance.
In this paper, the performance of earthen structures in recent earthquakes will be examined, analyzing failure
modes inherent to these particular construction materials and associated construction techniques. Also, seismic
reinforcement approaches and techniques will be presented in a comprehensive manner. Examples of tests conducted for the assessment of retrofitting solutions efficiency will be presented, and the results obtained will be discussed
Effect of the mechanical properties on drilling resistance of Al2O3-TiO2 coatings manufactured by atmospheric plasma spraying
Al2O3 with 13 and 45wt.% TiO2 microsized powders (6-22 and 13-41µm for each chemical composition) were used as raw materials to coat AISI 1040 steel by atmospheric plasma spraying. The mechanical properties of the coatings were measured by micro-indentation tests, and drilling experiments were carried out using high speed steel (HSS) rotary drill bits of various diameters and varying the load on the drill bits. In order to reduce the effect of the wear on the bit, a new bit was used for each test. According to the results, the drilling test is proposed as a method of determining the mechanical properties of these coatings from the correlation found between coating hardness and drilling resistance. © 2012 Elsevier B.V
El rol del control personal en la función paliativa de la justificación del sistema entre la población indígena y no indígena de estudiantes peruanos
Indexación: Scopus.In this article we propose a mediation model for the association between system justification and psychological well-being (i.e., the palliative function of ideology), based on system justification theory and compensatory control theory. Specifically, we argue that endorsing system-justifying beliefs leads to increased perceived personal control, which in turn predicts higher well-being. We used a convenience sample of students from two Peruvian universities. The results showed that system justification was related to general psychological well-being and personal control. In addition, indigenous students rated lower on system justification, general psychological well-being, self-esteem and personal control. Next, we found that the association between system justification and general psychological well-being was stronger among indigenous students, and this relationship was partially mediated by personal control. In addition, we showed that the mediation model is moderated by ethnicity, so that personal control is a mediator only among non-indigenous participants. We conclude that personal control is a mechanism involved in the palliative function of ideology among this group. Finally, we discuss possible explanations for the mechanisms involved in the palliative function of ideology among low-status individuals. © 2018, © 2018 Fundacion Infancia y Aprendizaje.En este artículo se propone un modelo de mediación de las
relaciones entre la justificación del sistema y el bienestar psicológico (i.e.,
la función paliativa de la ideología) basado en las teorías de la justificación
del sistema y del control compensatorio. En concreto, se propone que la
adopción de creencias justificativas del sistema produce un aumento del
control personal percibido que, a su vez, predice niveles más elevados de bienestar. En este estudio se utilizó una muestra por conveniencia de estudiantes
provenientes de dos universidades peruanas. Los resultados muestran
que la justificación del sistema está relacionada con el bienestar psicológico
general y con el control personal. Además, los estudiantes indígenas mostraron
niveles más reducidos de justificación del sistema, bienestar
psicológico general, autoestima y control personal. También se observó que
la relación entre la justificación del sistema y el bienestar psicológico general
era más fuerte entre los estudiantes indígenas y que el control personal
mediaba parcialmente en esta relación. Asimismo, mostramos que la etnicidad
es un factor moderador del modelo de mediación, por lo que el control
personal es un mediador únicamente entre los participantes no indígenas. El
estudio concluye que el control personal es un mecanismo que interviene en
la función paliativa de la ideología en este grupo. Por último, se discuten
posibles explicaciones de los mecanismos implicados en la función paliativa
de la ideología entre individuos de estatus social bajo.https://www.tandfonline.com/doi/full/10.1080/02134748.2018.153765
Sustainable and renewable hydrogen production from recycled aluminum
The whole world has been suffering strong consequences related to climate change. The intense use of fossil fuels in the chemical and automotive industries have put the environment in jeopardy. Thus, the industry has achieved a point of no return and it is urgent the development of renewable and sustainable technologies. Hydrogen has been pointed as a key component of the new era in industry since it can be produced in a clean and sustainable way. Currently the development of hydrogen fuel cells technology has put the automotive sector ahead of the chemical industries in relation to studies regarding the hydrogen production. Chemical industries produce hydrogen with technologies reliant on fossil fuels while the automotive sector has been looking for renewable forms of hydrogen generation. Trains powered by hydrogen fuel cells are a reality in Europe, for instance. Hydrogen generation technological advances must match the pace of the development of fuel cells electrical vehicles in order to the environmental goals and widespread application of fuel cell systems to be achieved. The present study addresses the hydrogen generation from the spontaneous reaction between aluminum and aqueous solution of sodium hydroxide. Aluminum is a metal that presents high exergetic value and can be recycled several times without losing its thermo-mechanical properties. That makes the use of aluminum especially appealing. It will make hydrogen generation a cleaner and more affordable process. Our findings demonstrate that it is possible to predict the kinetic behavior of the reaction using data obtained by the conductometric method. Graphs of electrical conductivity vs time show that is possible to verify the order of the reaction. We will present concepts of kinetic, thermodynamic and transport phenomena of the reaction between solid recycled aluminum and sodium hydroxide in an aqueous solution. The knowledge acquired throughout this study will contribute to the development of a new reactor and as a consequence, a new renewable and sustainable industrial system of hydrogen generation
A territorial view of the Chilean university system. The case of the regional University of Aysén (UAY)
Indexación: Scopus; Scielo.El análisis del caso de la Universidad de Aysén, que presenta este trabajo, permite describir y comprender algunas de las dificultades que muestran las universidades regionales en Chile para vincularse con su territorio e impactar en el desarrollo local. Este problema, que evidencia una arista de desigualdad y debilidad del sistema de educación chileno, es una constante en las diferentes evaluaciones nacionales e internacionales. Nuestra tesis es que estas dificultades son una de las tantas expresiones de la persistencia de un clivaje centro-periferia, que se manifiesta en una insensibilidad territorial o paradigma centralista de las políticas públicas en Chile, que con independencia de la orientación política del gobierno (democrática o autoritaria) o la preeminencia de la planificación estatal o del mercado como regulador del sistema, ha tendido a respuestas homogéneas y centralistas para enfrentar realidades y necesidades territoriales diversas.The analysis of the case of the University of Aysén presented in this work allows us to describe and understand
some of the difficulties that regional universities in Chile have in relation with their territory and their impact on
local development. This problem, which shows the inequality and weakness of the Chilean education system,
appears continually in various national and international assessments. Our thesis is that these difficulties are one
of the many expressions of the persistence of a center-periphery cleavage manifested in a territorial insensitivity
or centralist paradigm in public policies in Chile, which have been oriented towards homogeneous and centralist
responses in response to different needs and territorial realities. This situation happens regardless of the political
orientation of the government (democratic or authoritarian) or the pre-eminence of state or market planning as a
regulator of the system.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-07052018000100427&lng=en&nrm=iso&tlng=e
University transformation and quantification devices
Indexación: Scopus; Scielo.Las políticas de Educación Superior en Chile les demandan a las Universidades la instalación de dispositivos de gestión orientados a organizar, cuantificar y monitorear el trabajo académico. Pensando en las implicaciones del uso de estos dispositivos de gestión, este trabajo presenta los resultados de un análisis discursivo de 95 documentos de trabajo (Reglamentos, Bases de concurso, Formularios de acreditación) para conocer las interpelaciones que realiza a la labor universitaria. Mediante el método de análisis de discurso, se caracteriza la actuación de los documentos oficiales que regulan y transforman el trabajo académico. El estudio realizado evidencia que los dispositivos de gestión del Trabajo académico performan el trabajo mediante acciones tales como: establecer jerarquías entre las múltiples tareas de un académico y entre académicos, mediante criterios que no han sido discutidos por la comunidad profesional; objetivar procesos laborales y asumir consensos en torno a ello, desconociendo disputas y desacuerdos actuales; omitir el contexto de producción académica, construyendo una imagen del trabajo como proceso individual; y finalmente instando relaciones laborales individualizadas y competitivas.In Chile, higher education policies have required universities to adopt management tools related to the monitoring and quantification of academic work. Accordingly, this paper presents the results of a documentary study of 95 official documents concerning academic work (Regulations, Scholarship and Grant Application Guidelines and Accreditation Application Forms) in order to understand the regulations pertaining to academic work. Discourse analysis was used to determine how these documents are used in the university environment to regulate and transform the academic work. The present study shows that management tools adopted characterize the academic work through actions such as: establish hierarchies among the multiple tasks of a faculty member and among faculty members using criteria that have not been discussed by the academic community; objectify work processes and reach consensus over them, disregarding current disputes and disagreements; omit the context of academic production creating an image of work as an individual process; and finally urge the establishment of individualizing and competitive work relationships.http://ref.scielo.org/d2c4s
An Infrastructure for acquiring high quality semantic metadata
Because metadata that underlies semantic web applications is gathered from distributed and heterogeneous data sources, it is important to ensure its quality (i.e., reduce duplicates, spelling errors, ambiguities). However, current infrastructures that acquire and integrate semantic data have only marginally addressed the issue of metadata quality. In this paper we present our metadata acquisition infrastructure, ASDI, which pays special attention to ensuring that high quality metadata is derived. Central to the architecture of ASDI is a erification engine that relies on several semantic web tools to check the quality of the derived data. We tested our prototype in the context of building a semantic web portal for our lab, KMi. An experimental evaluation omparing the automatically extracted data against manual annotations indicates that the verification engine enhances the quality of the extracted semantic metadata
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