Revista Virtual de Química最新文献_第3页

Deacylative Allylation Reaction: A promising Approach for the Synthesis of Compounds Containing the Allyl Group at Quaternary Centers 脱酰基烯丙基化反应:合成四元中心含烯丙基化合物的一种有前途的方法

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230025

Luana Gonçalves de Souza, Magdalena Nascimento Rennó, Paulo Roberto Ribeiro Costa

引用次数: 0

Development and Validation of a Low Cost Electrolytic Cell for Quantifying Copper in Jewelry: an Experimental Proposal for Teaching Analytical Instrumental Chemistry 用于珠宝中铜定量的低成本电解池的开发与验证:分析仪器化学教学的实验建议

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230038

Maria Eduarda F. de Faria, Fernando de Melo Cruz, Gabriel Villar, L. D. da Silva, Valéria A. Alves

{"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}

引用次数: 0

There is Chemistry Here: Part VIII. Non-Timber Forest Products (NWFPs) 这里有化学:第八部分。非木材林产品(NWFPs)

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 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

引用次数: 0

Methods Based on Digital Image: from General Considerations to Chemistry Teaching 基于数字图像的方法:对化学教学的一般思考

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 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

引用次数: 0

Assessment of Scientific Production of Curcuma zedoaria (Christm.) Roscoe – Impacts and Trends since 1881 莪术(莪术)科学生产评价罗斯科-自1881年以来的影响和趋势

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230049

Alyne Gonçalves Bezerra, Rosa Maria de Brito Steckelberg, Danilo Brito Steckelberg, José Realino de Paula, Pierre Alexandre dos Santos

引用次数: 0

Evaluation of Macaúba Oil: Extractive Yield, Quality, Nutritional Indexes, and Biodiesel Lipid Profile 评价Macaúba油:提取产量，质量，营养指数，和生物柴油脂质剖面

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230047

Felipe Igor L. de Souza, Kalyl C. Lima, Wanderson S. de Lima, Regina M. Mendes Oliveira

{"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}

引用次数: 0

Reduced and Low-lactose Powdered Milk Production and Determination of its Physicochemical and Microstructural Properties During Storage 还原和低乳糖奶粉的生产及其贮存期间理化和显微结构特性的测定

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 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

引用次数: 0

The Federal Institute and the Licenciate Degree in Chemistry: The Paths to Become a Teacher Trainer in Different Spaces of Levels and Modalities 联邦学院和化学许可学位:在不同层次和模式的空间中成为教师培训师的路径

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230039

Nyuara A. da S. Mesquita, Francisca das Chagas A. da Silva

{"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}

引用次数: 0

Study of the Composition of Fractions of Manipueira: Solid and Liquid Residues Filtered on 0.45 µm Membrane and Qualitative Paper 0.45µm膜和定性纸过滤马尼普埃拉液、固渣组分的研究

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 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

{"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}

引用次数: 0

A Study on Gender and Sexuality in Chemistry Teaching 化学教学中性别与性行为的探讨

Revista Virtual de Química Pub Date : 2023-01-01 DOI: 10.21577/1984-6835.20230022

Isabelle Kuehlewein, Fernanda Luiza Faria, Keysy Solange Costa Nogueira

引用次数: 0