Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The objective of this work is to achieve significant learning and its better understanding by students who are studying Chemical Kinetics and Reactor Design Principles. Using the Excel solver as a didactic tool, it presents the analytical solution to the system of equations generated to determine the optimal size of CSTR reactors that operate in series in an isothermal and isobaric way. The procedure involves knowing the intermediate conversion achieved by each reactor to determine the optimal volume of each unit, which is described by the method of maximizing the area of rectangles on the Levenspiel curve, which is extrapolabled “n” reactor units, unlike the graphical method that is iterative and only practical up to three units.

La presencia de recursos digitales como las apps o aplicaciones móviles con un propósito educativo preciso y utilizado como herramienta complementaria a la labor docente flexibiliza y dinamiza, entre otras, el proceso de enseñanza/aprendizaje. En este estudio, se seleccionaron y evaluaron diferentes apps educativas relacionadas con el tema de balanceo de reacciones químicas. Las apps mejor evaluadas por los docentes e incluidas dentro del proceso de enseñanza/aprendizaje de estudiantes universitarios fueron Chem Calc - Equation Balancer & Element Dictionary y Chemical Equation Balance.La percepción general, después del uso de estos dos recursos, fue favorable y la calificación descriptiva que les otorgaron fue: motivantes, lúdicas, que diversifican la conducta del docente en cuanto a uso de recursos se refiere, que aumentan los espacios de participación por parte del estudiante e idóneas porque ayudan a mejorar su comprensión en el tema y a verificar los ejercicios que se hubiesen realizado.

The present work aims to give the reader a series of tools and instructions on the creation of simulated X-ray diffraction profiles for polycrystalline samples, using X-ray diffraction profiles previously published by open access databases. Initially, the search for the diffraction profiles of the crystalline phases must be carried out, which will integrate the simulated X-ray diffraction profile. Then, the operating mode is established to carry out the combination of 2 or more X-ray diffraction profiles, to generate a diffraction profile that contains the information 2 or more crystalline phases present, in proportions established by the user. Finally, this diffraction profile is tested using free access software for the analysis of crystalline phases present in X-ray diffraction profiles. The objective of this work is to provide didactic tools to teachers of analytical chemistry courses with emphasis on X-ray diffraction.

This manuscript describes a procedure for the estimation of IR, Raman, and NMR (1H and 13C) spectra of organic species using quantum-mechanical calculations to show undergraduate university students the implementation of simulation techniques in the elucidation of their molecular structures. Avogadro-1.2.0 (Hanwell et al., 2012) and Orca-5.0.3 (Neese, 2018) software were used for the elaboration of this procedure. This study shows that the harmonic vibrational frequencies and the signal intensities estimated for the Infrared spectra were acceptable and in correspondence with the experimental values. In contrast, the intensities of the Raman spectrum presented considerable deviations that can be attributed to the approach used for the estimation of the intensities of the spectrum and performing the quantum-mechanical calculations in the vacuum for the selected molecules. Instead, the signals from the 1H and 13C NMR spectra were obtained with a very good estimate based on the reported RMSE values.

Diversos historiadores de la ciencia, así como investigadores de la educación en ciencias (Izquierdo, 2010; Schütt, 2008; Kohler, 1971) han hablado de la existencia de un átomo químico y uno físico, para recuperar los procesos explicativos en los que se ha visto involucrada dicha entidad en los problemas propios de cada disciplina. Este análisis ha evidenciado no solo los diferentes intereses, aspiraciones y metodologías que persiguen la práctica de la química y de la física, sino también el estatus ontológico que adquieren las entidades como resultado del desarrollo de sus herramientas teóricas.            Este artículo muestra un panorama del proceso de construcción de la primer partícula subatómica identificada —el electrón— y del papel que desempeñó en las prácticas teóricas y experimentales que se estructuraron entorno a ella. Analizando la apropiación del electrón en la práctica de la física y de la química, pretendemos argumentar que también podemos hacer alusión a un electrón químico y uno físico. El propósito es que este análisis histórico confiera un reconocimiento más profundo del significado químico de esta entidad, con su consecuente repercusión en nuestros procesos de enseñanza-aprendizaje.

This article aims to analyze the tensions and reconfigurations that operate between illegalization, temporary borders and daily life of Haitians in Argentina, in connection with larger regional processes linked to the political government of Caribbean and African “extrarregional” migration in the recent South American context. I argue that the control over the modes of “permanence” of migrants of Haitian origin in Argentina represents a paradigmatic case that allows exposing regional trends in progress during the 2010s, based on the political exclusion of the refuge, the existence of differential criteria of residence, the reinforcement of illegalization mechanisms and the multiplication of temporary borders. In addition, I maintain that one of the main manifestations of these political processes is the “legal intermittency” referring to the conflictive and changing dynamics that is established between legal-political practices, temporary experiences of control and negotiation strategies of the subjects. The article adopts a qualitative methodological approach that includes, firstly, a documentary analysis of regulations and policies implemented at the regional level during the 2010s on Caribbean and African migration in Argentina, Brazil, Chile and Ecuador. Second, a participant observation and interviews conducted with migrants of Haitian origin between 2017 and 2019 in two cities in Argentina. I conclude that the link between legal borders and temporary borders constitutes a key aspect to understand both the political-administrative realities of the “new” migrations in the South American context, as well as the historically situated ways in which “configurations of illegality” permeate the projects of life and forms of resistance of specific national and social groups.

Feminists take a variety of different approaches to discussions of the law, and many researchers have focused on studying the possibility of employing feminist legal methods of “doing” and “knowing” in law. Feminist authors discuss the possibility of applying feminist methods to question truth claims in law and challenge the power relations the law creates and recreates based on markers such as gender, race, and class. We have organized our work around three components of a method developed by Katharine Bartlett—the woman question, feminist practical reasoning and consciousness-raising— to analyze the knowledge produced regarding the imprisonment of women for drug offenses in Brazil in the 21st century. We consider how feminist methods may be applied in this and other contexts which involve a great deal of marginalization. Drawing on Ochy Curiel’s interpretation of the concept of the coloniality of knowledge, we ask: How can we decolonize feminist methods in order to adapt them to the needs and realities of the Global South? We focus on the idea of translation, advocated for by a number of Latin American and North American authors whose work navigates on spaces of centrality (North) and marginality (South), as a method of producing “connected epistemologies” which encourage alliances and challenge reductionist interpretations of feminist theories. Our aim is to contribute to a horizontal dialogue between the Global North and South in feminist studies without disregarding the uniqueness of the realities of our research subjects.

In family justice, one of the biggest challenges is to effectively guarantee the right of children to participate. Though participation implies multiple benefits for the child, such as increased self-esteem, psychological wellbeing and preventing violations of rights, it is possible to detect many obstacles for it to effectively occur in court. Among these, prioritizing adults’ interests, conditioning participation of the child to their age and lack of formal regulations were noted. The present study consists of a thematic analysis of interviews with Chilean family judges about child participation. Findings point to a consideration of the infrastructure and the institutional legal organization as not being able to guarantee and facilitate child participation in the judicial system. Lack of standardization in norms and practices inside the courts encourages judges to base their decisions on their own personal abilities and criteria, frequently influenced by prejudice about revictimization and the capacity of children to exercise a meaningful participation related to their psychological development. In addition, considerations about how laws and family courts should promote child participation in family justice are discussed.

«Conformidad» is a very old institution in the Spanish criminal procedure system, since it dates back to the 19th century. In recent decades it has experienced a notable increase in its application as a negotiated criminal justice mechanism, as a result of several modifications in the Law of Criminal Procedure that have sought to introduce more space for negotiation in said figure and encourage its use. However, as an unwanted effect, such modifications have made the already convoluted regulation of said institute more complex, which makes it difficult to understand its physiognomy. This paper examines the current state of «conformidad» in the Spanish Criminal Procedure Law. Its scope of application, its requirements, its content, its processing and its effects are reviewed in the ordinary procedure, in the abbreviated procedure and in the fast procedure. A critical analysis of «conformidad» is also carried out from considerations made by the Spanish doctrine based on the complex normative reality and the not always consistent practice of the system, highlighting the fact that said institution generates certain risks for the accused, for the victim and for society. The work ends with some brief conclusions.

Law constitutes a device that serves the purpose of naturalizing the existing social order. This is because the cycle of protests observed since October 2019 in Chile, insofar as it was oriented to produce changes in the social order, puts pressure on the Law. Hence, it is possible to expect that the representations of political protest produced from the legal field during this cycle operate in diverse and opposing senses. In order to investigate the understanding of these meanings and to know how they are confronted, a judicial process oriented to the punishment of actions developed in the framework of these protests is examined. This type of analysis is relevant because what is debated in court has an impact on the discussion and definition of the content of the political rights of citizens. The proposed research is a contribution to the socio-legal understanding of protest, a right at the heart of democracy