Latin America's agricultural exports to China: Recent trends

Latin America is becoming the fastest growing agricultural production region and Brazil has by far the fastest growing agricultural sector. China from being a small agricultural importer (1.4% of world imports in 1990/01), became the fifth largest importer at 5.4% of world imports in 2006/07. China's overall trade with Latin America has expanded substantially during the last two decades -the rate of growth has been greater than any other region in the world since 2005. Most exports from Latin America to China are primary products while Chinese exports to Latin America are mostly industrial products. The Chinese demand for agricultural products is concentrated in food products such as grains and oilseeds. Countries specialised in those commodities -eg. Brazil and Argentina-exhibit a strong orientation on the Chinese market. In turn, growing subsectors in China, like fruits and vegetables, are posing strong competition to some world supplier countries in Latin America such as Chile and Peru. Since China is promoting structural reforms of its agricultural sector, aimed at increasing productivity and improving food security, and is expanding their direct investments overseas to secure provision of raw materials, Latin American governments need to pursue long-run strategic public policies. They need to optimize trade results and promote production efficiency that on one hand contribute to take advantage of the current market situation but at the same time assure the protection of the natural resources and preserve the production capacity and the agricultural diversity. --Latin America,China,trade,agriculture,soybean,agricultural policies

Mechanical Behavior of SLS Components in Relation to the Build Orientation During the Sintering Process as Measured by ESPI

Selective Laser Sintering (SLS) allows producing real parts from CAD data from materials with different characteristics compared to the final model, presenting dissimilar mechanical properties between the prototype and the product. The purpose of this work is to correlate the mechanical behavior of beam-type specimens produced by SLS with build orientation angle used as a process parameter, also attempting to demonstrate how this parameter affects the accuracy of the Empirical Similitude Method (ESM). ESM presents itself as a valuable tool when creating scale models with SLS, specifically in the framework of evolutionary product design. More specifically, the Young modulus variation of test specimens of well-known dimensions and material (DuraformTM PA2 ), will be characterized by loading them within the elastic range. The resulting elastic deformations will be measured using the technique of Electronic Speckle Pattern Interferometry (ESPI) for small deformations in an out-of-plane configuration, contrasting these results with the elastic theory of deformations. As a main result, it was found that there exists a linear correlation between the build angle and the elastic modulus of the parts. Secondly, it was demonstrated empirically that the ESM predicts better the mechanical response of the part than TSM. Moreover, a 30% error reduction can be achieved within the ESM when using the build orientation angle as a process parameter.Mechanical Engineerin

Architectural Indoor Analysis: A Holistic Approach to Understand the Relation of Higher Education Classrooms and Academic Performance

The influence of learning space on users has been broadly accepted and tested. However, the literature has focused on single factor research, instead of holistic approaches. Additionally, lower educational levels have been the focus of interest, while higher education is moving towards multi-method teaching. This paper focuses on how learning spaces for different purposes (practice and lecture rooms) may influence academic performance from a holistic approach of learning physical environment perception. For this, the iPEP scale (Indoor physical environment perception) is used and validated through Cronbach Alpha and Exploratory Factorial Analysis. Then, multiple linear regression is conducted. The results indicate that iPEP measures near to 63 percent of the construct, which is structured in six factors. Moreover, linear regression analyses support previous literature concerning the influence of learning physical environment on academic performance (R2 = 0.154). The differences obtained between practice and lecture room in terms of predictor variables bring to the light the need to diagnose learning environments before designing changes in educational buildings. This research provides a self-reported way to measure indoor environments, as well as evidence concerning the modern university, which desires to combine several teaching methods

BRAILLESHAPES : efficient text input on smartwatches for blind people

Tese de Mestrado, Engenharia Informática, 2023, Universidade de Lisboa, Faculdade de CiênciasMobile touchscreen devices like smartphones or smartwatches are a predominant part of our lives. They have evolved, and so have their applications. Due to the constant growth and advancements in technology, using such devices as a means to accomplish a vast amount of tasks has become common practice. Nonetheless, relying on touch-based interactions, requiring good spatial ability and memorization inherent to mobile devices, and lacking sufficient tactile cues, makes these devices visually demanding, thus providing a strenuous interaction modality for visually impaired people. In scenarios occurring in movement-based contexts or where onehanded use is required, it is even more apparent. We believe devices like smartwatches can provide numerous advantages when addressing such topics. However, they lack accessible solutions for several tasks, with most of the existing ones for mobile touchscreen devices targeting smartphones. With communication being of the utmost importance and intrinsic to humankind, one task, in particular, for which it is imperative to provide solutions addressing its surrounding accessibility concerns is text entry. Since Braille is a reading standard for blind people and provided positive results in prior work regarding accessible text entry approaches, we believe using it as the basis for an accessible text entry solution can help solidify a standardization for this type of interaction modality. It can also allow users to leverage previous knowledge, reducing possible extra cognitive load. Yet, even though Braille-based chording solutions achieved good results, due to the reduced space of the smartwatch’s touchscreen, a tapping approach is not the most feasible. Hence, we found the best option to be a gesture-based solution. Therefore, with this thesis, we explored and validated the concept and feasibility of Braille-based shapes as the foundation for an accessible gesture-based smartwatch text entry method for visually impaired people

A numerical study of planar detonations

A numerical study on the buildup and propagation of planar detonation waves in H2 + Air combustible mixtures, based on theuse of unsteady Euler equations coupled with source terms to account for rates controlled chemical activity, is presented. The computer solver works with 13 chemical species and 33 different one step reactions of a H2 O2 N2 combustion mechanism. The detonation process is initiated via the energy provided by an igniter which acts as a driver of a shock tube driving through a combustible mixture a blast (or strong shock), accompanied by exothermic chemical changes. It is shown that for each equivalence ratio of the combustible mixture, the detonation can only be triggered if the igniter energy deposition equals or exceeds a computed minimum value. When the igniter energy deposition is less than this minimum, the combustion zone start to decouple from the blast front and if that energy is diminished even more, the combustion could nottake place. A particular way of generating sustained overdriven detonations, is also considered.Fil: Tamagno, José. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Elaskar, Sergio Amado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: García, Jorge O.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentin

A numerical study of planar detonations

A numerical study on the buildup and propagation of planar detonation waves in H2 + Air combustible mixtures, based on theuse of unsteady Euler equations coupled with source terms to account for rates controlled chemical activity, is presented. The computer solver works with 13 chemical species and 33 different one step reactions of a H2 O2 N2 combustion mechanism. The detonation process is initiated via the energy provided by an igniter which acts as a driver of a shock tube driving through a combustible mixture a blast (or strong shock), accompanied by exothermic chemical changes. It is shown that for each equivalence ratio of the combustible mixture, the detonation can only be triggered if the igniter energy deposition equals or exceeds a computed minimum value. When the igniter energy deposition is less than this minimum, the combustion zone start to decouple from the blast front and if that energy is diminished even more, the combustion could nottake place. A particular way of generating sustained overdriven detonations, is also considered.Fil: Tamagno, José. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Elaskar, Sergio Amado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: García, Jorge O.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentin

Procesos de transformación urbana en áreas centrales. Aportes para el abordaje de la gentrificación en américa latina

Luego de un proceso extendido de suburbanización, las transformaciones más notables de las ciudades comienzan a observarse en las áreas centrales y se caracterizan especialmente por afectar la composición social, la actividad económica y las prácticas culturales preexistentes; traduciéndose en desplazamientos de población y cambios de tipologías edilicias, usos y costumbres locales. Este tipo de situaciones han sido analizadas en Europa y Estados Unidos desde los años sesenta bajo el concepto de gentrificación.En América Latina estos fenómenos comienzan a analizarse recién a principios del siglo XXI. Esto se debe a las propias características del proceso de urbanización latinoamericano, que tiene lugar en un período posterior; así como también a sus condiciones socioeconómicas y políticas particulares.Habiendo identificado esta situación, se presenta un análisis conceptual de la gentrificación, sus principales causas y consecuencias y las especificidades y desafíos que asume su abordaje y estudio en América Latina

Los procesos de integración y cooperación en África. El papel de Angola

Los procesos de integración y cooperación en África han ocupado un lugar destacado tanto en la esfera regional africana como internacionalmente. Desde la creación de la Unión Africana, en sustitución a la Organización para la Unidad Africana (OUA), se esperaba que la nueva organización - concebida a partir de una solicitud emitida por los jefes del Estado y de Gobierno de la OUA, en la Declaración el 9 de septiembre de 1999 (Declaración de Sirte,) basada en el modelo de la Unión Europea y del NAFTA (Acuerdo de Comercio Libre de América del Norte) -, junto con sus Comunidades Económicas regionales, cumpliera con el objetivo de facilitar un rápido proceso de integración económica y política en el continente y en la economía global y fuera capaz, de abordar los problemas sociales, económicos y políticos del continente africano que se agravaban por ciertos aspectos negativos originados principalmente por los conflictos. Cuando en julio de 2000, en Lomé, capital de Togo, fue adoptado el Acto Constitutivo del la Unión Africana (UA) y, en los años siguientes se establecieron los distintos programas de actuación, han sido muchos los cuestionamientos sobre dichos procesos y su eficacia en la concretización de los objetivos a que se había propuesto; hasta entonces mucho ha caído la credibilidad de los instrumentos que utiliza para el mantenimiento de la paz y seguridad en el continente africano, negando la importancia de su papel en la escena internacional. Con la presente investigación se pretende analizar los procesos de integración y cooperación en África, evaluando específicamente la actuación de la Unión Africana en la resolución de los conflictos, mantenimiento de la paz y la seguridad en África y sus Comunidades Económicas Regionales. Nos centraremos en el estudio particular de Angola, su historia, política interior, económica y exterior y su papel para el avance de dichos procesos..