ABSTRACT In analytical chemistry laboratories, the basic principles of the study of the chemical composition of a material or sample are verified experimentally, through different methods of analysis, for which reason chemical and biological agents are handled daily, to which workers are exposed; hence the need to assess the risk of exposure. The objective of this work was to evaluate the risks in an analytical chemical laboratory using the semi-quantitative method of William Fine, for which a multidisciplinary commission was created made up of specialists and experts with experience in the subject. It was determined that there is a direct relationship between the chemical, fire and explosion risks, the emanation of vapors of volatile substances, due to very high temperatures, or close to sources of ignition that can cause a fire, and generate a chain of events that, when reacting with other substances, can lead to explosions. The chemical and fire risks were evaluated as critical risks, which require immediate stoppage of the activity, and the mechanical, environmental, explosion, and biological risks were evaluated as notable risks, which require an urgent necessary correction.

RESUMEN En los laboratorios de química analítica se verifican de forma experimental, los principios básicos del estudio de la composición química de un material o muestra, mediante diferentes métodos de análisis, por lo que se manipulan diariamente agentes químicos y biológicos, a los están expuestos los trabajadores; de ahí la necesidad de evaluar el riesgo de exposición. Este trabajo tuvo como objetivo evaluar los riesgos en un laboratorio químico analítico mediante el método semicuantitativo de William Fine, para lo cual se creó una comisión multidisciplinaria constituida por especialistas y expertos con experiencia en el tema. Se determinó que xiste una relación directa entre el riesgo químico, el de incendio y el de explosión la emanación de vapores de sustancias volatiles, debido a temperaturas muy altas, o próximas a fuentes de ignición que puedan provocar un incendio, y generar una cadena de acontacimientos que al reaccionar con otras sustancias pueden dar lugar a explosiones. Los riesgos químico y de incendios fueron evaluados como riesgos criticos los cuales requieren de detención inmediata de la actividad y los riesgos mecánico, ambiental, de explosión y biológico fueron evaluados como riesgos notables por lo que requieren una correción necesaria urgente.

The demand for macadamia nut production worldwide has led to increased use of pesticides and chemicals for pest and disease control. Reservoirs in these macadamia farming sectors are at risk, since these chemicals can enter and contaminate the water through direct application, runoff, and atmospheric deposition, subsequently negatively affecting aquatic organisms. The current study investigated macroinvertebrate colonisation and succession associated with two macadamia orchards and two communal area reservoirs. The potential effects of stressors from these land uses was tested for and compared using stone substrates over a 6-week period. Stone substrates from both reservoir types were abundantly colonised over time and the total macroinvertebrate taxa and abundance showed an increasing trend across the sampled weeks, with macadamia orchards having the highest number of macroinvertebrate taxa. Strong ecological succession was observed across reservoirs, with the initial succession of early colonisers - i.e., Chironominae (collector-gatherers), Ostracoda (collector-filterers) and Anax sp. (predator) within communal area reservoirs, and Chironominae, Ostracoda and Radix natalensis (scrapers) in macadamia orchard reservoirs - followed by predatory colonisers such as Gyrinidae larvae, Trithemis sp. (macadamia orchard reservoirs), and Ranatra sp. (communal area reservoirs). Macroinvertebrate community structure differed significantly across sites and weeks, with no similarity being observed for communities across the different reservoirs. Redundancy analyses further highlighted 11 sediment chemistry variables (i.e., pH, resistivity, P, K, Na, Ca, Mg, Cu, B, Fe and S) which were significantly related to macroinvertebrate community structure. Thus, sediment variables were found to be better predictors of macroinvertebrate community structure in macadamia orchard reservoirs than communal area reservoirs. Consequently, we concluded that differences in colonisation ability among taxa and environmental stressors were important factors driving succession. These results add to the understanding of the macroinvertebrate colonisation processes and environmental stressors within agricultural landscapes, which can aid in the development of conservation management of freshwater ecosystems.

Resumo A Química Verde (QV) emerge em consequência de uma série de discussões ambientais globais no final do século XX, preocupando-se com a minimização ou eliminação de resíduos gerados nas rotas sintéticas. Em razão dessa gênese, esse apelo marcadamente industrial e laboratorial tem resultado em uma lenta apropriação na área de ensino. Em 2018, o grupo CTS e Educação, do CEFET/RJ realizou um mapeamento de artigos sobre o ensino de QV no Brasil publicados até o 1º semestre de 2017 e constatou essa atuação incipiente. Sendo assim, com o objetivo de rever e atualizar esses dados até o 1º semestre de 2022, o presente trabalho apresenta os resultados de um novo mapeamento realizado a partir da análise de redes sociais. Os grafos expuseram um crescimento apreciável do número de publicações e instituições vinculadas nos últimos anos, salientando que o cenário brasileiro de publicações sobre o ensino de QV está em ascendência. Além disso, notou-se um avanço na relevância do enfoque CTS e da experimentação para a concretização da área. Por fim, Vânia Zuin e Carlos Alberto Marques consagraram-se mais uma vez como referências de autores, destacando-se, nos resultados atuais, os trabalhos de Marilei Sandri.

Abstract Green Chemistry (GC) emerged due to a series of global environmental discussions at the end of the 20th century, concerned with minimizing or eliminating waste generated in synthetic routes. Due to this genesis, this markedly industrial and laboratorial appeal has resulted in a slow appropriation in education. In 2018, the STS and Education group of CEFET/RJ mapped articles on GC teaching in Brazil published until the 1st semester of 2017 and found this incipient performance. Thus, to review and update this data until the 1st semester of 2022, the present work presents the results of a new mapping using social network analysis. The graphs exposed a noticeable growth in the number of publications and associated institutions in recent years, highlighting the rising Brazilian scenario of publications on GC teaching. Moreover, it was noted an advance in the relevance of STS approach and experimentation for the area realization. Finally, Vânia Zuin and Carlos Alberto Marques have established themselves once again as author references, highlighting, in the current results, the work of Marilei Sandri.

Resumen El artículo describe las características fisicoquímicas y microbiológicas tanto del sistema de abastecimiento de agua potable existente en el distrito Las Brisas, ubicado en el cantón de Zarcero, como del agua superficial del río Jilguero que atraviesa dicha comunidad. Se valora el impacto negativo de las actividades humanas sobre el recurso hídrico durante los años 2019-2021 para determinar su vulnerabilidad a partir del análisis de 45 muestras de agua dulce. Los resultados más importantes son: 1- Existen niveles de amonio y de fosfato en el agua del acueducto, provenientes del expansivo desarrollo agropecuario, que, durante la estación lluviosa, escurren y lixivian a las nacientes. 2- El pH y el cloro libre son dos parámetros que requieren ser mejorados en el acueducto las Brisas, para reducir los riesgos y asegurar la potabilidad del agua en toda la red de distribución. 3- La contaminación del río Jilguero se clasifica entre moderada y severa según normativa nacional, situación generada por la intensa actividad agropecuaria en la zona, así como el irrespeto a las zonas de protección del río.

Abstract The article describes the physicochemical and microbiological characteristics of both the existing drinking water supply system in the Las Brisas district located in the canton of Zarcero, and the surface water of the Jilguero River that crosses said community. The negative impact of human activities on water resources during the years 2019-2021 is assessed to determine its vulnerability based on the analysis of 45 freshwater samples. The most important results are: 1- There are levels of ammonium and phosphate in the aqueduct water that, during the rainy season, run off and leach into the springs, coming from the expansive agricultural development. 2- The pH and free chlorine are two parameters that need to be improved in the Las Brisas aqueduct, to reduce risks and ensure the potability of the water throughout the distribution network. 3- The contamination of the Jilguero River is classified between moderate and severe according to national regulations, a situation motivated by the intense agricultural activity in the area, as well as the disrespect for the river's protection zones.

RESUMEN Los estiércoles y efluentes animales son considerados una fuente de nutrientes para satisfacer la demanda de los cultivos, mantener la fertilidad del suelo y lograr mejores rendimientos de los cultivos. Sin embargo, a nivel nacional existe poca información sobre los efectos de la aplicación de efluentes porcinos sobre indicadores de calidad del suelo en situaciones reales de campo. Por lo tanto, el objetivo de este estudio fue detectar cambios en propiedades químicas y microbiológicas del suelo, por aplicación prolongada de efluente porcino. Seis establecimientos porcinos localizados en el sudeste de la provincia de Córdoba fueron seleccionados como sitios de estudio. Dos tratamientos fueron definidos en cada sitio: suelos con aplicación prolongada de efluente porcino y suelos sin aplicación de efluente. Se realizaron muestreos de suelo en 0-10 y 10-20 cm para la determinación de indicadores químicos y microbiológicos. Se evidenció incrementos significativos en el nitrógeno (N) orgánico del suelo, fósforo extractable (Pe) y conductividad eléctrica (CE) en ambas profundidades. Mientras que el carbono orgánico particulado, potasio y sodio (Na) se incrementaron, y pH disminuyó en superficie, con aplicaciones de efluente. El incremento en el Na se vio reflejado también en el porcentaje de Na intercambiable. En cuanto a los indicadores microbiológicos, la aplicación de efluentes estimulo las actividades enzimáticas e incrementó el potencial de mineralización del N (p<0,05). En conclusión, las aplicaciones de efluente lograron incrementar la fertilidad del suelo y la actividad microbiológica. Sin embargo, se debe prestar atención a los incrementos en Pe, Na y CE, para evitar impactos ambientales negativos, como eutrofización de cursos de agua, salinización o sodificación de los suelos agrícolas.

ABSTRACT Animal manures and slurry are considered nutrient sources for meeting crop nutrient demands, maintaining soil fertility, and improving crop yields. However, there is limited national information available on the effects of pig slurry application on soil quality indicators in real field scenarios. Thus, the aim of this study was to identify changes in the chemical and microbiological soil properties resulting from the prolonged application of pig slurry. Six pig farms situated in the southeastern region of the Córdoba province were chosen as study sites. Two treatments were established at each site: soils with pig slurry application and soils without pig slurry application. Soil assessments were conducted at depths of 0-10 cm and 10-20 cm to determine chemical and microbiological properties. Significant increases in soil organic nitrogen (SON), extractable phosphorus (Pe), and electrical conductivity (EC) were observed at both depths. In addition, there were increases in particulate organic carbon, potassium, and sodium (Na), along with a decrease in pH in the topsoil, due to pig slurry applications. The elevation in Na levels also affected the percentage of exchangeable sodium. Regarding microbiological indicators, the application of slurry stimulated enzymatic activities and increased the potential for N mineralization (p<0.05). In conclusion, the application of pig slurry led to enhanced soil fertility and microbiological activity. However, careful consideration should be given to the increases in Pe, Na, and EC to prevent adverse environmental effects like watercourse eutrophication, salinization, or the sodification of agricultural soils.

Abstract Objective. To evaluate how the tasks carried out by the students in the scope of the PVC educational citizen science project for monitoring the quality of coastal waters contributed to raising their awareness of the problems of marine litter, in particular, the pollution of the ocean by plastics and microplastics, and the importance of chemistry in society. Methods. The project stage here presented consisted of six asynchronous tasks, conducted with digital mediation through the Moodle platform. The project took place in the 2018/2019 school year and involved 442 students and nine chemistry teachers from a middle school in the northern coastal region of Portugal. Data on the impact on students' awareness of the contexts considered were collected from the outputs the students produced in each task. The data were analyzed using the content analysis technique. Discussion. From this analysis emerged indicators of the PVC project's positive contribution to raising students' awareness of the pollution of marine environments by (micro)plastics, as well as raising awareness of the role of chemistry in society. The students expressed positive opinions toward this science and recognized its links with other areas of science and technology. Conclusión. Thus, it was found that citizen science projects significantly promote students' awareness of chemical-environmental subjects by exploring current and relevant contexts.

Resumen Objetivo. Evaluar cómo las tareas desarrolladas por estudiantes dentro del proyecto educativo de ciencia ciudadana PVC para monitorear la calidad de las aguas costeras contribuyeron a la promoción de su conciencia sobre el problema de la basura marina, en particular, la contaminación del océano por plásticos y microplásticos, y la importancia de la química en la sociedad. Metodologia. La etapa del proyecto presentada aquí consistió en un conjunto de seis tareas asincrónicas, realizadas con mediación digital a través de la plataforma Moodle que tuvo lugar en el año escolar 2018/2019 e involucró a 442 estudiantes y nueve docentes de química de la escuela secundaria en la región costera norte de Portugal. Los datos sobre el impacto en la conciencia estudiantil de los contextos discutidos se recolectaron a partir de los registros generados por el estudiantado en cada tarea y se analizaron utilizando la técnica de análisis de contenido. Discusión. De este análisis surgieron indicadores de la contribución positiva del proyecto PVC en la sensibilización del estudiantado sobre la contaminación de los entornos marinos por (micro)plásticos, así como en la sensibilización sobre el papel de la química en la sociedad, con estudiantes con opiniones positivas hacia esta ciencia y que reconocen sus conexiones con otras áreas de la ciencia y la tecnología. Conclusión. Se constató que, a través de la exploración de contextos actuales y relevantes, los proyectos de ciencia ciudadana tienen un gran potencial para promover la conciencia estudiantil sobre temas químico-ambientales.

Resumo Objetivo. Avaliar de que modo as tarefas desenvolvidas pelos alunos no âmbito do projeto educacional de ciência cidadã PVC de monitorização da qualidade das águas costeiras contribuíram para a promoção da sua consciencialização para a problemática do lixo marinho, em particular, da poluição do oceano por plásticos e por microplásticos e para a importância da Química na sociedade. Metodologia. A etapa do projeto que aqui se apresenta era constituída por um conjunto de seis tarefas assíncronas, realizadas com mediação digital através da plataforma Moodle que decorreu durante o ano letivo 2018/2019 e envolveu 442 alunos e nove professores do 3.º Ciclo do Ensino Básico da região norte litoral de Portugal. Dados sobre o impacto na consciencialização dos alunos para os contextos abordados foram recolhidos a partir dos registos elaborados pelos alunos em cada tarefa, e foram, posteriormente, analisados com recurso à técnica de análise de conteúdo. Discussão. Da análise destes resultados emergiram indicadores do contributo positivo do projeto PVC na consciencialização dos alunos para a poluição dos ambientes marinhos por (micro)plásticos bem como na sensibilização para o papel da Química na sociedade, tendo os alunos demonstrado opiniões positivas face a esta ciência e reconhecido as suas inter-relações com outras áreas da ciência e da tecnologia. Conclusão. Constatou-se assim que, através da exploração de contextos atuais e relevantes, que os projetos de ciência cidadã apresentam um grande potencial na promoção da sensibilização dos alunos para as temáticas químico-ambientais.

ABSTRACT: The dwarf shrubiands of Empetrum rubrum in the Magellanic steppe are unique habitats due to their growth in acidic and nutrient-poor soils. The objective of this study was to describe the vegetation and environmental variables that characterize this type of environment. Significant differences were found between continental dwarf shrubs and those located northeast of Tierra del Fuego Island in terms of species richness and diversity. Despite apparent erosion, the proportion of native species was higher than that of introduced species. The dominant growth habit in terms of coverage were the dwarf dwarf shrublands of E. rubrum on the continent and those of Baccharis magellanica on Tierra del Fuego Island. Seven lichens were also found in the dwarf shrubs. The dominant life form were hemicryptophytes or perennial herbs, indicating that these shrublands are not under severe anthropogenic pressure, but do have high levels of erosion, which are likely the result of past overgrazing. The physical and chemical soil properties analyzed, which showed significant differences between the dwarf shrubs, were N-NO3, Mg, K, Na, CICE, and silt. On the other hand, Canonical Correspondence Analysis (CCA) revealed an important soil gradient, where pH and organic matter, along with the content of macronutrients (N, P, K), determine differences between the dwarf shrubs. Finally, it is recommended to pay more attention to the management and conservation of these shrublands, considering that they may be affected by anthropogenic management such as grazing, mining interventions, and water deficit, as has occurred in the northern hemisphere where they have left the soil bare.

RESUMEN: Los matorrales enanos de Empetrum rubrum en la estepa magallánica, son hábitats únicos debido a que crecen en suelos ácidos y pobres en nutrientes. El objetivo de este estudio, fue describir la vegetación y las variables ambientales que caracterizan este tipo de ambiente. Se encontraron diferencias significativas entre los murtillares continentales y los ubicados al noreste de la isla de Tierra del Fuego, en términos de riqueza de especies y diversidad. A pesar de la aparente erosión, la proporción de especies nativas fue mayor que la de especies introducidas. El hábito de crecimiento dominante en términos de cobertura fueron los subarbustos enanos de E. rubrum en el continente y los de Baccharis magellanica en la isla de Tierra del Fuego. También se encontraron siete líquenes en los murtillares. La forma de vida dominante fueron las hemicriptofitas o hierbas perennes, lo anterior indica, que estos matorrales no están bajo una severa presión antropogénica, pero si presenta niveles altos de erosión que seguramente son la consecuencia del sobrepastoreo ocurrido en el pasado. Las propiedades físico-químicas del suelo analizadas, que mostraron diferencias significativas entre los murtillares fueron N-NO3, Mg, K, Na, CICE y el limo. Por otra parte, el Análisis Correspondencia Canónica (CCA) reveló un importante gradiente del suelo, donde el pH y la materia orgánica, junto con el contenido de macronutrientes (N, P, K), determinan diferencias entre los murtillares. Finalmente, se recomienda prestar más atención a la gestión y conservación de estos matorrales, considerando que estos pueden ser afectados por el manejo antrópico, como el pastoreo, las intervenciones mineras y el déficit hídrico, como ha ocurrido en el hemisferio norte, donde han dejado el suelo desnudo.

Resumen En el presente trabajo se presenta el desarrollo y los resultados de una experiencia destinada a la enseñanza de la química en las cátedras de Ingeniería y Ciencia de los materiales y Polímeros de la carrera de Ingeniería Química. La experiencia consistió en la elaboración de un barniz a partir de residuos de poliestireno expandido. Este enfoque tiene relación con el cuidado medioambiental y la reutilización de los residuos poliméricos en el desarrollo de productos de valor agregado. Este trabajo se llevó a cabo durante el trascurso del año lectivo 2022 en diferentes encuentros. Las tareas se realizaron en conjunto con estudiantes avanzados de Ingeniería Química a fin de complementar la actividad experimental e incorporar conceptos sobre polímeros, soluciones, propiedades de materiales, entre otros. Los principales resultados muestran que es posible obtener barnices basados en poliestireno expandido recuperado, con precios competitivos y propiedades aceptables, y que los estudiantes logran mediante estas experiencias fortalecer sus conocimientos en el área de polímeros, y sensibilizarse en la importancia del cuidado del medio ambiente.

Abstract This work presents the development and results of an experience aimed at teaching chemistry in the courses of Materials Engineering and Polymers of the Chemical Engineering career. A varnish was prepared from expanded polystyrene waste. This approach is related to environmental care and the reuse of polymeric waste in the development of value-added products. This work was carried out during the 2022 school year in different meetings. The tasks were carried out with advanced students of Chemical Engineering to complement the experimental activity and incorporate concepts of polymers, solutions, and material properties, among others. The main results show that it is possible to obtain varnishes based on recovered expanded polystyrene with competitive prices and acceptable properties and that students achieve through these experiences to promote their knowledge in polymers and become aware of the importance of caring for the environment.

Ground-level ozone (O3) is an air pollutant of major health and environmental concern. The Johannesburg-Pretoria megacity in South Africa is the industrial and economical capital of the country with more than 10 million inhabitants experiencing poor air quality. In 2004, the City of Johannesburg (CoJ) began monitoring trace gases to assess ground-level O3 pollution. Here, we use CoJ's publicly available air quality data, and present the first long-term data analysis of O3, nitric oxide (NO), nitrogen dioxide (NO2), NOx and carbon monoxide (CO) in the City from 2004 to 2011 at three air quality monitoring sites: Buccleuch, Delta Park and Newtown. We quantified CoJ's South African National Ambient Air Quality Standards (NAAQS) exceedances for O3 and NO2, and demonstrate the City's substantial O3 and NO2 air pollution problem. O3 mixing ratios peak in the early afternoon as expected due to photochemical production. To estimate O3 production rates, we summed O3 and NO2 diurnal profiles to obtain Ox mixing ratios at each site. This analysis provided insight into missing volatile organic compound (VOC) reactivity as well as primary NO2 emissions information necessary for developing tropospheric O3 pollution mitigation strategies. Furthermore, CoJ experiences high O3 mixing ratios on weekends due to lower NOx traffic emissions titrating the O3, thereby providing evidence of a VOC-limited regime for O3 production. Seasonal peak O3 occurs in the austral spring, a maximum that we link to increases in water (H2O) concentrations which in turn increases radical chemistry leading to O3. In addition, wintertime VOC and aerosol emissions from biomass burning over the winter add important precursors for O3 formation once radical chemistry is initiated during the first rain events in early spring. In all, this study will help inform air quality modelling and policy work on air pollutants in the City of Johannesburg, South Africa.

Resumen Contextualizar los laboratorios de química, relacionándolos con situaciones de la vida diaria y contenidos disciplinares, motiva a despertar vocaciones científicas. El objetivo del trabajo fue fomentar el interés por las ciencias exactas y el cuidado medioambiental, a través de la participación activa de los estudiantes en la reutilización del aceite vegetal como modelo de laboratorio en contexto. Durante los talleres se estudió el origen de los aceites vegetales, las implicancias sobre la salud de la reiterada reutilización del aceite vegetal, las posibles formas de transformación en nuevos productos, la transesterificación, y la manipulación de reactivos químicos. Los destinatarios fueron estudiantes del nivel medio de 6 instituciones diferentes de la provincia de Misiones (Argentina), ascendiendo a un total de 45 estudiantes de entre 17 a 21 años. Los talleres estuvieron a cargo de estudiantes, graduados y las directoras del proyecto. La metodología de la actividad consistió en una experiencia práctica y evaluación de la intervención. El empleo de un contexto socioambiental para la enseñanza de la química, generó concientización acerca de los cuidados del medioambiente; y nuevo conocimiento en relación con la química, al hacer uso de la reacción de transesterificación para la obtención de biodiesel.

Abstract Contextualizing chemistry laboratories, relating them to daily life situations and disciplinary contents, motivates to awaken scientific vocations. The objective of the work was to promote interest in exact sciences and environmental care, through the active participation of students in the reuse of vegetable oil as a laboratory model in context. The origin of vegetable oils, the health implications of the repeated reuse of vegetable oil, the possible forms of transformation into new products, transesterification, and the manipulation of chemical reagents were studied during the workshops. Recipients were high school students from 6 different institutions in the province of Misiones (Argentina), reaching a total of 45 students between 17 and 21 years old. Workshops were led by students, graduates and the directors of the project. The methodology of the activity consisted of a practical experience and evaluation of the intervention. The use of a socio-environmental context for the teaching of chemistry, generated awareness about environmental care; and new knowledge in relation to chemistry, by making use of the transesterification reaction to obtain biodiesel.

BACKGROUND: Global population growth and ageing are factors that contribute towards an anticipated increase in the usage of spectacles and contact lenses for vision correction. The subsequent disposal of polymeric vision corrective devices currently, has uncertain environmental impacts. AIM: The purpose of this study was to explore potential environmental impacts and end-of-life (EOL) pathways of a sample of polymeric spectacle lenses and through the use of analytical chemistry processes. SETTING: Laboratory analysis of ophthalmic lenses. METHODS: Inductively coupled plasma-optical emission spectroscopy (ICP-OES), elemental analysis and calorific value investigations were conducted on a sample of spectacle lenses and contact lenses. RESULTS: Metal ion analysis by ICP-OES confirmed the presence of manganese in all the lenses and chromium in two of the 13 contact lenses. All of the lenses had over 42% carbon while calorific values of up to 32.40 MJ/kg and 23.31 MJ/kg were found in the spectacle lenses and contact lenses, respectively. CONCLUSION: Further investigation is required regarding the presence of chromium in two of the contact lenses. In general, lenses are likely to remain as solid waste in landfills depending on the disposal conditions. Considering their calorific values, lenses would be useful in incineration with energy recovery processes however the suggested ideal EOL route would be the implementation of lens recycling, through non-toxic and green chemical processes, to retain material value and promote a circular economy. CONTRIBUTION: This study provides new information on the environmental consequences of current modes of lens disposal and suggests EOL alternatives thereof.

Humankind has experienced a remarkable development since it began to design and optimize chemical reactions to achieve valuable compounds. The key to accomplish these tasks is the proper understanding of how chemical transformations occur at a molecular level, that is, their reaction mechanisms. Based on a suitable mechanistic proposal, experimentalists choose a given chemical protocol to optimize experimental conditions, design new synthetic routes, and circumvent competing reactions. In this context, computational chemistry has become a valuable ally for mechanistic elucidation. We present herein a review of complementary collaborations between experimentalists and theoretical chemists to rationalize processes at the molecular level, focusing mainly on the fields of organic synthesis, natural product chemistry, and systems with environmental interest. Throughout this review, we highlight the ability of computational evaluations to provide answers to questions raised from experiments in a clear and direct way, indicating to experimentalists alternative paths to help them solve their problems. compounds level mechanisms proposal conditions routes context elucidation synthesis interest way problems

Resumo: Este artigo tem o objetivo de apresentar um desenho metodológico para atividades experimentais, que busca o desenvolvimento de uma formação crítica, por meio da transformação do pensamento, para uma consciência crítica sobre a ciência e suas relações sobre a realidade social, econômica e ambiental. Para tanto, os principais referenciais teóricos que configuram essa metodologia derivam da Teoria Crítica, a partir do conceito de formação crítica, das características que orientam o trabalho experimental investigativo e sobre as concepções e princípios da Química Verde e Sustentável. Baseada nessas perspectivas teórico-metodológicas emerge a Abordagem Experimental Formativa que, organizada em cinco fases, se propõe a contribuir na superação das visões simplistas que comprometem a compreensão sobre o papel da Experimentação e a construção de caminhos teóricos e metodológicos que viabilizem uma formação mais crítica para o Desenvolvimento Sustentável. Resumo experimentais pensamento social ambiental tanto Crítica Sustentável teóricometodológicas teórico metodológicas fases

Abstract: This article aims to present a methodological design for experimental activities that seeks to develop a critical, reflexive education, through the change of mind and critical awareness of science and its relations to social, economic, and environmental realities. Therefore, the primary theoretical references that configure this methodology derive from Critical Theory, from the characteristics that guide investigative experimental work, and the concepts and principles of Green and Sustainable Chemistry. Based on these theoretical-methodological perspectives, the Formative Experimental Approach emerges, organized into five phases. The study aims to contribute to overcoming simplistic visions that compromise the understanding of the role of Experimentation and the construction of theoretical and methodological paths that enable a more critical approach to sustainable development. Abstract education social economic realities Therefore Theory work Chemistry theoreticalmethodological perspectives emerges phases development

Pesticides present utmost importance in modern agriculture and are extensively used in countries with strong agricultural activity, such as Brazil. However, these substances are considered a significant part of environmental contamination by organic compounds. In the present work, Raman spectroscopy was employed in the vibrational characterization of the fungicide tebuconazole and surface-enhanced Raman scattering spectroscopy to the study of the adsorption of this compound on the surface of Ag nanoparticles. The proposed chemical interaction between tebuconazole and the metallic surface was inferred by relating experimental results and vibrational assignment supported by density functional theory calculations. The vibrational assignments of surface-enhanced Raman scattering spectra, by considering surface selection rules, suggest that the adsorption of the tebuconazole with Ag surface occurs by interactions of phenyl and triazole groups simultaneously. For the case of the interaction with the phenyl group, a modification of the charge distribution in the ring after adsorption was hypothesized, which was supported through the analysis of the frontier molecular orbitals of the Ag-tebuconazole complex calculated by density functional theory. activity Brazil However compounds work surfaceenhanced enhanced nanoparticles calculations spectra rules simultaneously group hypothesized Agtebuconazole

Considering the current environmental problems associated with the growing world demand for energy arising from development and population growth, the need to diversify energy matrices, such as the implementation of solar energy, is highlighted. Thus, it is important to discuss this topic in the school environment, because when they are introduced from childhood to high school, the probability of this orientation being effective is much greater. In this context, educational games have attracted attention as a teaching tool, combining a fun atmosphere with the improvement of learning. This work aimed the production and application of a game in board format representing a dye-sensitized solar cell (CSSC) as a didactic resource in approaching the content of energy conversion. The game allowed an easy visualization of how the energy conversion process is performed by a CSSC. It was presented during the scientific dissemination event “Café com Ciência”, promoted by the Federal University of São João del-Rei, with good results both in gameplay aspects and in helping to understand the theme. The feedback obtained indicates that the game can be a useful tool for students and educators, reaching all its didactic potential and facilitating learning in the face of complex concepts.