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

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

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

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

Estudo do Efeito das Enzimas no Consumo Energético do Processo de Refinação na Fabricação de Papel Tissue

O presente estudo tem como objetivo investigar uma forma de diminuir o consumo energético durante o processo de preparação das fibras e, avaliar, se com a adição de enzimas na pasta é possível atingir-se uma redução significativa na energia consumida. É também avaliado se esta adição de enzimas provoca algum efeito nas propriedades das fibras e do papel tissue, como o índice de drenabilidade, resistência à tração e espessura. Como tal, foi estudada a aplicação de uma mistura de enzimas de composição desconhecida (Mistura E) em duas misturas de pastas diferentes (Mistura A utilizada na Experiência 1 e Mistura B utilizada na Experiência 2), para a fabricação de dois tipos de papel (15,5 g/m2 e 19 g/m2). Este estudo, foi realizado à escala industrial, em ambiente fabril, no qual a enzima foi adicionada no pulper durante a fase de desagregação. Verificou-se que o tratamento enzimático aumentou o índice de drenabilidade (°SR) e melhorou as propriedades de resistência do papel produzido, em ambas as experiências. Atingiu-se uma redução média no consumo energético dos refinadores, na Experiência 1, de 75% e 58% para o papel de 15,5 g/m2 e 19 g/m2, respetivamente e, na Experiência 2, de 58% e 51%, onde se chegou à conclusão de que o uso da Mistura A, utilizada na Experiência 1, é benéfico para se obter uma maior poupança energética. A aplicação de enzimas nas pastas utilizadas não só favoreceu a poupança energética, como ainda melhorou as propriedades da folha de papel tissue. Este resultado indica que os tratamentos enzimáticos na indústria do papel, podem vir a tornar-se cada vez mais frequentes para se atingir uma produção mais sustentável e com menores impactos ambientais.The aim of this study is to investigate a way of reducing energy consumption during the fiber preparation process and to assess whether a significant reduction in energy con- sumption can be achieved by adding enzymes to the pulp. It also assesses whether this addi- tion of enzymes has any effect on the properties of the fibers and tissue paper, such as the drainability, tensile strength, and thickness. As such, the application of a mixture of enzymes of unknown composition (Mixture E) in two different pulp mixtures (Mixture A used in Exper- iment 1 and Mixture B used in Experiment 2) was studied for the manufacture of two types of paper (15.5 g/m2 and 19 g/m2). This study was carried out on an industrial scale, in a factory environment, where the enzyme was added to the pulper during the disintegration phase. It was found that the enzyme treatment increased the drainability (°SR) and improved the strength properties of the paper produced in both experiments. An average reduction in refiner energy consumption was achieved in Experiment 1 of 75% and 58% for 15.5 g/m2 and 19 g/m2 paper, respectively, and in Experiment 2 of 58% and 51%, which led to the conclu- sion that the use of Mixture A, used in Experiment 1, is beneficial for achieving greater energy savings. The application of enzymes to the pulps used not only favored energy savings, but also improved the properties of the tissue paper sheet. This result indicates that enzymatic treat- ments in the paper industry may become increasingly common to achieve more sustainable production with less environmental impact