Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230025
Luana Gonçalves de Souza, Magdalena Nascimento Rennó, Paulo Roberto Ribeiro Costa
{"title":"Deacylative Allylation Reaction: A promising Approach for the Synthesis of Compounds Containing the Allyl Group at Quaternary Centers","authors":"Luana Gonçalves de Souza, Magdalena Nascimento Rennó, Paulo Roberto Ribeiro Costa","doi":"10.21577/1984-6835.20230025","DOIUrl":"https://doi.org/10.21577/1984-6835.20230025","url":null,"abstract":"","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82218605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230038
Maria Eduarda F. de Faria, Fernando de Melo Cruz, Gabriel Villar, L. D. da Silva, Valéria A. Alves
The quantitative determination of Cu in solution by electrodeposition on Pt electrode using instrumentation is a classic experiment in Instrumental Analytical Chemistry, to introduce the fundamentals of electrogravimetry. However, this practice cannot always be performed, given the high cost of Pt electrodes, which are generally not available in academic institutions. In this work, an alternative system was developed and validated. The Pt electrodes were replaced by a graphite rod extracted from an exhausted battery (anode) and copper, obtained from scraps of copper pipes from a refrigeration system (cathode). The deposition yields of the conventional (using Pt electrodes) and alternative systems were 100.6 ± 1.0% and 96.31 ± 2.64%, respectively. The alternative system was applied to determine the percentage of Cu (m/m) in a jewelry sample, obtaining 90.56 ± 1.37%. This work brings contributions to the works in the literature, where the efficiency of the alternative system is compared with that of the conventional system, and the pair of electrodes used as cathode and anode has not yet been used for Cu electrodeposition. The experiment was planned where the electrolysis time is approximately 1.5 h, and contributes to the economy of electric energy consumption and with the environment.
{"title":"Development and Validation of a Low Cost Electrolytic Cell for Quantifying Copper in Jewelry: an Experimental Proposal for Teaching Analytical Instrumental Chemistry","authors":"Maria Eduarda F. de Faria, Fernando de Melo Cruz, Gabriel Villar, L. D. da Silva, Valéria A. Alves","doi":"10.21577/1984-6835.20230038","DOIUrl":"https://doi.org/10.21577/1984-6835.20230038","url":null,"abstract":"The quantitative determination of Cu in solution by electrodeposition on Pt electrode using instrumentation is a classic experiment in Instrumental Analytical Chemistry, to introduce the fundamentals of electrogravimetry. However, this practice cannot always be performed, given the high cost of Pt electrodes, which are generally not available in academic institutions. In this work, an alternative system was developed and validated. The Pt electrodes were replaced by a graphite rod extracted from an exhausted battery (anode) and copper, obtained from scraps of copper pipes from a refrigeration system (cathode). The deposition yields of the conventional (using Pt electrodes) and alternative systems were 100.6 ± 1.0% and 96.31 ± 2.64%, respectively. The alternative system was applied to determine the percentage of Cu (m/m) in a jewelry sample, obtaining 90.56 ± 1.37%. This work brings contributions to the works in the literature, where the efficiency of the alternative system is compared with that of the conventional system, and the pair of electrodes used as cathode and anode has not yet been used for Cu electrodeposition. The experiment was planned where the electrolysis time is approximately 1.5 h, and contributes to the economy of electric energy consumption and with the environment.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88286257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230048
Patricia G. Ferreira, Cristina M. Hüther, Wilson C. Santos, Luana da Silva Magalhães Forezi, Fernando de Carvalho da Silva, Vitor Francisco Ferreira
{"title":"There is Chemistry Here: Part VIII. Non-Timber Forest Products (NWFPs)","authors":"Patricia G. Ferreira, Cristina M. Hüther, Wilson C. Santos, Luana da Silva Magalhães Forezi, Fernando de Carvalho da Silva, Vitor Francisco Ferreira","doi":"10.21577/1984-6835.20230048","DOIUrl":"https://doi.org/10.21577/1984-6835.20230048","url":null,"abstract":"","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135501995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230060
Claudinéia Rosa da Silva Oliveira, Willian Toito Suarez, Helena Rosa dos Anjos Nahas, Fábio Junior Moreira Novaes, João Paulo Barbosa de Almeida, Vagner Bezerra dos Santos
{"title":"Methods Based on Digital Image: from General Considerations to Chemistry Teaching","authors":"Claudinéia Rosa da Silva Oliveira, Willian Toito Suarez, Helena Rosa dos Anjos Nahas, Fábio Junior Moreira Novaes, João Paulo Barbosa de Almeida, Vagner Bezerra dos Santos","doi":"10.21577/1984-6835.20230060","DOIUrl":"https://doi.org/10.21577/1984-6835.20230060","url":null,"abstract":"","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"279 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135703815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230049
Alyne Gonçalves Bezerra, Rosa Maria de Brito Steckelberg, Danilo Brito Steckelberg, José Realino de Paula, Pierre Alexandre dos Santos
Knowledge about scientific production is important to direct and optimize new studies. Curcuma zedoaria , from the Zingiberaceae family, has been used for thousands of years. The objective of this study was to know the scientific production of the species, with the indicators: scientific production; authorship; cross-country collaboration; impact factor; research trends and applicability of research. We use bibliometrics and scientometrics tools with searches in the Web of Science and Scopus databases
{"title":"Assessment of Scientific Production of Curcuma zedoaria (Christm.) Roscoe – Impacts and Trends since 1881","authors":"Alyne Gonçalves Bezerra, Rosa Maria de Brito Steckelberg, Danilo Brito Steckelberg, José Realino de Paula, Pierre Alexandre dos Santos","doi":"10.21577/1984-6835.20230049","DOIUrl":"https://doi.org/10.21577/1984-6835.20230049","url":null,"abstract":"Knowledge about scientific production is important to direct and optimize new studies. Curcuma zedoaria , from the Zingiberaceae family, has been used for thousands of years. The objective of this study was to know the scientific production of the species, with the indicators: scientific production; authorship; cross-country collaboration; impact factor; research trends and applicability of research. We use bibliometrics and scientometrics tools with searches in the Web of Science and Scopus databases","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135956727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230047
Felipe Igor L. de Souza, Kalyl C. Lima, Wanderson S. de Lima, Regina M. Mendes Oliveira
Vegetable oils have various industrial applications in the food, pharmaceutical, and bioenergy fields, but economic valorization is mainly associated with cultivation, extraction, and their physical, chemical, and biological properties. Thus, the aim of the study was to extract oil from the macaúba almond ( Acrocomia aculeata ), a native species from the cerrado region, at an advanced stage of ripeness (i.e., collected two months after the mature fruit has fallen to the ground) and investigate its physicochemical and anti-inflammatory characteristics, as well as its lipid and nutritional profile. Analytical methods used were based on AOCS (American Oil Chemists Society) standards and ANVISA recommendations and pharmacopoeial assays. The oil was obtained through artisanal extraction, with a yield of 26.18% relative to the almond mass, a value higher than what is generally reported for this raw material. Based on density, moisture content, refractive indices, acidity, peroxide, and saponification values, the oil meets quality parameters. The atherogenicity and thrombogenicity index values indicate that macaúba almond oil is less nutritionally suitable compared to fruit pulp and olive oils. Chromatographic data show that the oil contains a high content of saturated fatty acids (70.48%), indicating its economic value addition potential, especially in biodiesel production.
{"title":"Evaluation of Macaúba Oil: Extractive Yield, Quality, Nutritional Indexes, and Biodiesel Lipid Profile","authors":"Felipe Igor L. de Souza, Kalyl C. Lima, Wanderson S. de Lima, Regina M. Mendes Oliveira","doi":"10.21577/1984-6835.20230047","DOIUrl":"https://doi.org/10.21577/1984-6835.20230047","url":null,"abstract":"Vegetable oils have various industrial applications in the food, pharmaceutical, and bioenergy fields, but economic valorization is mainly associated with cultivation, extraction, and their physical, chemical, and biological properties. Thus, the aim of the study was to extract oil from the macaúba almond ( Acrocomia aculeata ), a native species from the cerrado region, at an advanced stage of ripeness (i.e., collected two months after the mature fruit has fallen to the ground) and investigate its physicochemical and anti-inflammatory characteristics, as well as its lipid and nutritional profile. Analytical methods used were based on AOCS (American Oil Chemists Society) standards and ANVISA recommendations and pharmacopoeial assays. The oil was obtained through artisanal extraction, with a yield of 26.18% relative to the almond mass, a value higher than what is generally reported for this raw material. Based on density, moisture content, refractive indices, acidity, peroxide, and saponification values, the oil meets quality parameters. The atherogenicity and thrombogenicity index values indicate that macaúba almond oil is less nutritionally suitable compared to fruit pulp and olive oils. Chromatographic data show that the oil contains a high content of saturated fatty acids (70.48%), indicating its economic value addition potential, especially in biodiesel production.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136004385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230031
Igor Lima de Paula, Laís Lima Melquíades, Ítalo Tuler Perrone, Erica Felipe Mauricio, Biany Aparecida de Castro Dias, Antônio Fernandes de Carvalho, L. F. Cappa de Oliveira, R. Stephani
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230039
Nyuara A. da S. Mesquita, Francisca das Chagas A. da Silva
The paper presents an excerpt of a doctoral research that focused on the Federal Institutes, their historical setting and teaching practice, where different levels and modalities of teaching coexist. The consolidated licenciate degrees in the IF show formative paths that are materialized in the diversity, and the research investigated the structuring of the teacher profile identity of the IF trainer teacher and their experiential teaching knowledge at different levels and modalities. The praxeological knowledge of Pierre Bourdieu and his relational analysis system is the theoretical background used to correlate the teacher and the arrangements of the institution. We used the Critical Communicative Methodology (CCM) to analyze 14 semi-structured questionnaires applied to licenciate degree trainers at five campuses. The MCC identified the obstacle element fragmentation in levels category, it comes from the performance in a level and/or modality. In which, we identified a certain distance of the teacher from the institution internal dynamics, mainly from the interaction between High School Education and College Education. The transforming element of interlevel teaching category showed a plural, versatile and adaptable teaching profile to the institutional dynamics. The diversity of the IF makes it possible to design training paths that internalize the interactivity of experiences in the high school education and chemical teacher training, expanding the view of the trainer to the profession.
{"title":"The Federal Institute and the Licenciate Degree in Chemistry: The Paths to Become a Teacher Trainer in Different Spaces of Levels and Modalities","authors":"Nyuara A. da S. Mesquita, Francisca das Chagas A. da Silva","doi":"10.21577/1984-6835.20230039","DOIUrl":"https://doi.org/10.21577/1984-6835.20230039","url":null,"abstract":"The paper presents an excerpt of a doctoral research that focused on the Federal Institutes, their historical setting and teaching practice, where different levels and modalities of teaching coexist. The consolidated licenciate degrees in the IF show formative paths that are materialized in the diversity, and the research investigated the structuring of the teacher profile identity of the IF trainer teacher and their experiential teaching knowledge at different levels and modalities. The praxeological knowledge of Pierre Bourdieu and his relational analysis system is the theoretical background used to correlate the teacher and the arrangements of the institution. We used the Critical Communicative Methodology (CCM) to analyze 14 semi-structured questionnaires applied to licenciate degree trainers at five campuses. The MCC identified the obstacle element fragmentation in levels category, it comes from the performance in a level and/or modality. In which, we identified a certain distance of the teacher from the institution internal dynamics, mainly from the interaction between High School Education and College Education. The transforming element of interlevel teaching category showed a plural, versatile and adaptable teaching profile to the institutional dynamics. The diversity of the IF makes it possible to design training paths that internalize the interactivity of experiences in the high school education and chemical teacher training, expanding the view of the trainer to the profession.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85671333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230029
Ingrid Karen Lira Melo, Maria Célia Tavares, João Paulo Tenório da Silva Santos, Janesmar Camilo de Mendonça Cavalcanti, W. Botero, V. Del Colle
Cassava, is an important crop in the national agricultural and economic scenario. Its processing generates waste, such as manipueira, which has several applications but can cause environmental impact when improperly disposed of. This work aimed to evaluate the physicochemical characteristics of manipueira in different fractions (suspended solid, filtered at 0.45 μm, and in a common filter). The fractions were characterized physicochemically (pH and conductivity) and chemically using the following techniques: i) total organic carbon (TOC), ii) elemental analysis (CNHS), iii) MP-AES and infrared atomic emission spectrometry iv) SCP and AGNES. The resulting TOC values reflect a potential for the application of the material as a biofertilizer. The pH of manipueira is outside the standard established by Brazilian legislation. The metals Ba, Cd, Ni and Pb, and Zn, from the filtrate at 0.45 μm, are within the maximum limits established by CONAMA 430/2011resolution, while Cr, in the two filtrates, and Zn from the filtrate of the common filter, is above the maximum limits. Using SCP and AGNES it was possible to determine the presence of Pb in the solid residue as well as in the samples filtered at 0.45 μm, indicating the necessity of adequate treatment of the effluent before discard.
{"title":"Study of the Composition of Fractions of Manipueira: Solid and Liquid Residues Filtered on 0.45 µm Membrane and Qualitative Paper","authors":"Ingrid Karen Lira Melo, Maria Célia Tavares, João Paulo Tenório da Silva Santos, Janesmar Camilo de Mendonça Cavalcanti, W. Botero, V. Del Colle","doi":"10.21577/1984-6835.20230029","DOIUrl":"https://doi.org/10.21577/1984-6835.20230029","url":null,"abstract":"Cassava, is an important crop in the national agricultural and economic scenario. Its processing generates waste, such as manipueira, which has several applications but can cause environmental impact when improperly disposed of. This work aimed to evaluate the physicochemical characteristics of manipueira in different fractions (suspended solid, filtered at 0.45 μm, and in a common filter). The fractions were characterized physicochemically (pH and conductivity) and chemically using the following techniques: i) total organic carbon (TOC), ii) elemental analysis (CNHS), iii) MP-AES and infrared atomic emission spectrometry iv) SCP and AGNES. The resulting TOC values reflect a potential for the application of the material as a biofertilizer. The pH of manipueira is outside the standard established by Brazilian legislation. The metals Ba, Cd, Ni and Pb, and Zn, from the filtrate at 0.45 μm, are within the maximum limits established by CONAMA 430/2011resolution, while Cr, in the two filtrates, and Zn from the filtrate of the common filter, is above the maximum limits. Using SCP and AGNES it was possible to determine the presence of Pb in the solid residue as well as in the samples filtered at 0.45 μm, indicating the necessity of adequate treatment of the effluent before discard.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"175 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91532454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21577/1984-6835.20230022
Isabelle Kuehlewein, Fernanda Luiza Faria, Keysy Solange Costa Nogueira
This article presents the results of a state-of-the-art research that aimed to investigate the theme of gender and sexuality in the teaching of chemistry. The mapping of research was carried out from 2010 to 2021 in the Brazilian Digital Library of Theses and Dissertations of Capes (Coordination for Higher Education Personnel Improvement) and in the Portal of Periodicals of Capes. In the National Meeting of Chemistry Teaching and National Meeting of Research in Science Education, the period was from 2010 to 2020. 43 works were identified that involved the theme, however only 8 researches involved chemical contents. A large part of the inventoried researches encouraged the participation of women in the scientific career. In this sense, it is inferred that the theme gender and its nature involving chemical concepts are still incipient in chemistry classes.
{"title":"A Study on Gender and Sexuality in Chemistry Teaching","authors":"Isabelle Kuehlewein, Fernanda Luiza Faria, Keysy Solange Costa Nogueira","doi":"10.21577/1984-6835.20230022","DOIUrl":"https://doi.org/10.21577/1984-6835.20230022","url":null,"abstract":"This article presents the results of a state-of-the-art research that aimed to investigate the theme of gender and sexuality in the teaching of chemistry. The mapping of research was carried out from 2010 to 2021 in the Brazilian Digital Library of Theses and Dissertations of Capes (Coordination for Higher Education Personnel Improvement) and in the Portal of Periodicals of Capes. In the National Meeting of Chemistry Teaching and National Meeting of Research in Science Education, the period was from 2010 to 2020. 43 works were identified that involved the theme, however only 8 researches involved chemical contents. A large part of the inventoried researches encouraged the participation of women in the scientific career. In this sense, it is inferred that the theme gender and its nature involving chemical concepts are still incipient in chemistry classes.","PeriodicalId":21315,"journal":{"name":"Revista Virtual de Química","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86047571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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