Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230012
M. Vila, Rodrigo Boscariol, V. Balcão
Curcumin, a phytochemical, exhibits several biological properties and has been studied for the treatment of psoriasis. To facilitate its transdermal permeation, permeation enhancers such as choline and geranic acid ionic liquid (CAGE-IL) have been studied. From this perspective, the research effort entertained herein aimed at developing and evaluating the stability of an emulsion prepared with curcumin (phytochemical from Curcuma longa L.) and locust bean gum (extracted from the seeds of the carob tree, Ceratonia siliqua), with CAGE-IL as a facilitator of transdermal permeation. Stability studies were carried out for six months, with analyses being performed at time intervals of 0 (24 h), 30, 60, 90, and 180 days. The samples were kept at 40 ± 2 °C, with 75 ± 5% relative humidity (RH). The parameters analyzed were morphological characteristics, pH (5.8-6.0), and spreadability. The samples were shown to be stable during the timeframe studied, maintaining adequate physicochemical characteristics and meeting quality specifications for cutaneous applications. CAGE-IL, in addition to facilitating permeation of the active substance, also favored the formation of a stable emulsion encompassing nanosized particles (134.3 ± 2.6 nm) in a simple fashion and with only a few components.
{"title":"NANOSTRUCTURED CURCUMIN WITH CHOLINE AND GERANIC ACID IONIC LIQUID (CAGE-IL): POTENTIAL FOR INCORPORATION INTO PHARMACEUTICAL GEL FORMULATIONS","authors":"M. Vila, Rodrigo Boscariol, V. Balcão","doi":"10.21577/0100-4042.20230012","DOIUrl":"https://doi.org/10.21577/0100-4042.20230012","url":null,"abstract":"Curcumin, a phytochemical, exhibits several biological properties and has been studied for the treatment of psoriasis. To facilitate its transdermal permeation, permeation enhancers such as choline and geranic acid ionic liquid (CAGE-IL) have been studied. From this perspective, the research effort entertained herein aimed at developing and evaluating the stability of an emulsion prepared with curcumin (phytochemical from Curcuma longa L.) and locust bean gum (extracted from the seeds of the carob tree, Ceratonia siliqua), with CAGE-IL as a facilitator of transdermal permeation. Stability studies were carried out for six months, with analyses being performed at time intervals of 0 (24 h), 30, 60, 90, and 180 days. The samples were kept at 40 ± 2 °C, with 75 ± 5% relative humidity (RH). The parameters analyzed were morphological characteristics, pH (5.8-6.0), and spreadability. The samples were shown to be stable during the timeframe studied, maintaining adequate physicochemical characteristics and meeting quality specifications for cutaneous applications. CAGE-IL, in addition to facilitating permeation of the active substance, also favored the formation of a stable emulsion encompassing nanosized particles (134.3 ± 2.6 nm) in a simple fashion and with only a few components.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20170971
E. Santos, Wilmo Ernesto Francisco Junior
WHAT ARE THE PURPOSES FOR READING IN EDUCATION IN CHEMISTRY? ANALYSIS OF ARTICLES PUBLISHED IN JOURNALS OF RESEARCH IN SCIENCE EDUCATION BETWEEN 2010 AND 2021. This work investigated Brazilian academic production about reading in chemistry classes published in journals of research in science education. To this end, a literature review was conducted from sixteen journals between 2010 and 2021. Two main aspects were analyzed: indicators of production (papers per year and per journals, education level, geographic region and institutions of the study) and the purposes of the activities of reading. In terms of the indicators of production, the results pointed out a consistent interest on this issue in the last decade with papers published in diverse journals, regional predominance from the Southeast and concentration of publications in high school or university levels. Regarding the purposes of reading, three main categories were identified: reading for information, reading for the development of skills and reading for scientific communication. Besides, different genre of texts has been employed in reading practices. Among the challenges are the reduction of regional asymmetries, the addressing of studies for other levels of education, as well as the increasing of research and systematic practices of reading based on a critical point of view.
{"title":"PARA QUÊ SE LÊ NA EDUCAÇÃO EM QUÍMICA? UMA ANÁLISE DE PUBLICAÇÕES EM PERIÓDICOS DE EDUCAÇÃO EM CIÊNCIAS ENTRE 2010 E 2021","authors":"E. Santos, Wilmo Ernesto Francisco Junior","doi":"10.21577/0100-4042.20170971","DOIUrl":"https://doi.org/10.21577/0100-4042.20170971","url":null,"abstract":"WHAT ARE THE PURPOSES FOR READING IN EDUCATION IN CHEMISTRY? ANALYSIS OF ARTICLES PUBLISHED IN JOURNALS OF RESEARCH IN SCIENCE EDUCATION BETWEEN 2010 AND 2021. This work investigated Brazilian academic production about reading in chemistry classes published in journals of research in science education. To this end, a literature review was conducted from sixteen journals between 2010 and 2021. Two main aspects were analyzed: indicators of production (papers per year and per journals, education level, geographic region and institutions of the study) and the purposes of the activities of reading. In terms of the indicators of production, the results pointed out a consistent interest on this issue in the last decade with papers published in diverse journals, regional predominance from the Southeast and concentration of publications in high school or university levels. Regarding the purposes of reading, three main categories were identified: reading for information, reading for the development of skills and reading for scientific communication. Besides, different genre of texts has been employed in reading practices. Among the challenges are the reduction of regional asymmetries, the addressing of studies for other levels of education, as well as the increasing of research and systematic practices of reading based on a critical point of view.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68268904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230001
A. Dantas, Matheus Levy Almeida Taveira de Souza, Patrícia Ferreira Alexandre De Lima, M. Lima, D. Santana, Ricardo Maranho, A. Colonese, S. Ochs, M. Monteiro
DEVELOPMENT OF A METHODOLOGY FOR THE DETERMINATION OF CANNABINOIDS IN CANNABIS-BASED PRODUCTS FOR MEDICINAL PURPOSES. Medicinal products based on the Cannabis sativa plant are available in Brazil, among them, drug, cannabis products, individual import products, and those provided by patient associations. Despite this, there is no monograph for the evaluation of cannabinoids in Brazilian Pharmacopoeia (BP) or other compendia accepted. Therefore, this work aimed to develop a quick and easy method to quantify cannabinoids in authorized products for medicinal purposes. The method was developed by HPLC-UV, gradient elution composed of formic acid in acetonitrile and water, the flow rate of 0.6 mL min-1 and 220 nm detection. It was possible to resolve the peaks of cannabidiol (CBD), tetrahydrocannabinol (THC), cannabidiolic acid and cannabinol and to quantify CBD (105.35%; 104.07%) and THC (106.62%). The developed method was applied to two products and met the established requirements of precision, accuracy, linearity, and selectivity. This procedure has been tested on four cannabisbased products to attest to its effectiveness. Considering the importance of establishing minimum quality requirements for medicinal products and considering the available products in Brazil, it was found that it is important to evaluate the implementation of other products in the method developed for future validation and later inclusion in the BP.
开发一种测定药用大麻产品中大麻素的方法。在巴西可以获得以大麻植物为基础的医药产品，其中包括药品、大麻产品、个人进口产品和患者协会提供的产品。尽管如此，在巴西药典(BP)或其他可接受的药典中没有大麻素评价的专著。因此，本工作旨在开发一种快速简便的方法来定量药用授权产品中的大麻素。该方法采用HPLC-UV，甲酸在乙腈和水中组成梯度洗脱，流速为0.6 mL min-1，检测波长为220 nm。可以分辨出大麻二酚(CBD)、四氢大麻酚(THC)、大麻二酸和大麻酚的峰，并定量测定CBD (105.35%;104.07%)和THC(106.62%)。结果表明，该方法在精密度、准确度、线性度、选择性等方面均满足要求。这个程序已经在四种大麻产品上进行了测试，以证明其有效性。考虑到建立药品最低质量要求的重要性，以及考虑到巴西可获得的产品，我们发现，在制定的方法中评估其他产品的实施情况是很重要的，以便将来验证和以后纳入BP。
{"title":"DESENVOLVIMENTO DE METODOLOGIA PARA DETERMINAÇÃO DE CANABINOIDES EM PRODUTOS À BASE DE CANNABIS PARA FINS MEDICINAIS","authors":"A. Dantas, Matheus Levy Almeida Taveira de Souza, Patrícia Ferreira Alexandre De Lima, M. Lima, D. Santana, Ricardo Maranho, A. Colonese, S. Ochs, M. Monteiro","doi":"10.21577/0100-4042.20230001","DOIUrl":"https://doi.org/10.21577/0100-4042.20230001","url":null,"abstract":"DEVELOPMENT OF A METHODOLOGY FOR THE DETERMINATION OF CANNABINOIDS IN CANNABIS-BASED PRODUCTS FOR MEDICINAL PURPOSES. Medicinal products based on the Cannabis sativa plant are available in Brazil, among them, drug, cannabis products, individual import products, and those provided by patient associations. Despite this, there is no monograph for the evaluation of cannabinoids in Brazilian Pharmacopoeia (BP) or other compendia accepted. Therefore, this work aimed to develop a quick and easy method to quantify cannabinoids in authorized products for medicinal purposes. The method was developed by HPLC-UV, gradient elution composed of formic acid in acetonitrile and water, the flow rate of 0.6 mL min-1 and 220 nm detection. It was possible to resolve the peaks of cannabidiol (CBD), tetrahydrocannabinol (THC), cannabidiolic acid and cannabinol and to quantify CBD (105.35%; 104.07%) and THC (106.62%). The developed method was applied to two products and met the established requirements of precision, accuracy, linearity, and selectivity. This procedure has been tested on four cannabisbased products to attest to its effectiveness. Considering the importance of establishing minimum quality requirements for medicinal products and considering the available products in Brazil, it was found that it is important to evaluate the implementation of other products in the method developed for future validation and later inclusion in the BP.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68268961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230006
A. Cubas, A. Dutra, Thiago Alves, R. Bianchet, Adriano Rambo, N. Debacher
Tetracyclines comprise a large group of broad-spectrum antibiotics used in human and veterinary medicine. Its mechanism of action, via oral ingestion, is to inhibit bacterial protein synthesis, but a large amount (70%) is eliminated without being metabolized, which presents a risk for the arising of antibiotic-resistant species. In this study, the degradation of Tetracycline TC by non-thermal plasma NTP and the antimicrobial sensitivity of the treated solution are investigated. The degradation was followed by chromatographic analysis while the efficiency of NTP in inhibiting the action of TC on bacteria was evaluated by antimicrobial sensitivity test by disk diffusion method. The results showed a high rate of TC degradation, over 90%, in 10 min of NTP treatment for a 60 mL (107 mg L-1) sample and very slow increase up to 94% in 30 min. The antimicrobial sensitivity test of TC after degradation by NTP showed no antibiotic activity. Therefore, our findings are encouraging, since the removal efficiency is below the minimum threshold require, to prevent with high probability, outgrowth of antibiotic-resistant bacteria. In addition, the results confirm that the NTP treated solution is safe to the environment.
{"title":"EVALUATION OF ANTIMICROBIAL SENSITIVITY TO TETRACYCLINE EXPOSED TO NON-THERMAL PLASMA","authors":"A. Cubas, A. Dutra, Thiago Alves, R. Bianchet, Adriano Rambo, N. Debacher","doi":"10.21577/0100-4042.20230006","DOIUrl":"https://doi.org/10.21577/0100-4042.20230006","url":null,"abstract":"Tetracyclines comprise a large group of broad-spectrum antibiotics used in human and veterinary medicine. Its mechanism of action, via oral ingestion, is to inhibit bacterial protein synthesis, but a large amount (70%) is eliminated without being metabolized, which presents a risk for the arising of antibiotic-resistant species. In this study, the degradation of Tetracycline TC by non-thermal plasma NTP and the antimicrobial sensitivity of the treated solution are investigated. The degradation was followed by chromatographic analysis while the efficiency of NTP in inhibiting the action of TC on bacteria was evaluated by antimicrobial sensitivity test by disk diffusion method. The results showed a high rate of TC degradation, over 90%, in 10 min of NTP treatment for a 60 mL (107 mg L-1) sample and very slow increase up to 94% in 30 min. The antimicrobial sensitivity test of TC after degradation by NTP showed no antibiotic activity. Therefore, our findings are encouraging, since the removal efficiency is below the minimum threshold require, to prevent with high probability, outgrowth of antibiotic-resistant bacteria. In addition, the results confirm that the NTP treated solution is safe to the environment.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230003
Lúcio Freitas Neto, B. Espósito
In recent years, the safety of sunscreens to coral reefs and the role these products would play in the process of coral bleaching has been a concern. However, the discussion centers almost exclusively on the organic components used as UV filters, with little attention given to inorganic UV filters, such as zinc oxide. Zinc oxide nanoparticles (ZnO-NPs) have been a common ingredient of sunscreen formulations for decades and are being discharged in coral reef environments. Even though there are data supporting that ZnO is toxic to certain species of fish and algae, regulatory agencies do not appear concerned with the possible outcome of the exposure of corals and their algal symbionts to this metal oxide. This review compiles the published work on the toxicity of ZnO and ZnO-NPs to corals and zooxanthellae, which strongly supports the notion that zinc oxide is toxic to both corals and microalgae. In view of this, concern has been raised by the use of the “reef safe” label to promote sunscreens that lack specific organic components, however containing ZnO as the major UV filter.
{"title":"TOXICITY OF ZINC OXIDE TO SCLERACTINIAN CORALS AND ZOOXANTHELLAE: A BRIEF REVIEW","authors":"Lúcio Freitas Neto, B. Espósito","doi":"10.21577/0100-4042.20230003","DOIUrl":"https://doi.org/10.21577/0100-4042.20230003","url":null,"abstract":"In recent years, the safety of sunscreens to coral reefs and the role these products would play in the process of coral bleaching has been a concern. However, the discussion centers almost exclusively on the organic components used as UV filters, with little attention given to inorganic UV filters, such as zinc oxide. Zinc oxide nanoparticles (ZnO-NPs) have been a common ingredient of sunscreen formulations for decades and are being discharged in coral reef environments. Even though there are data supporting that ZnO is toxic to certain species of fish and algae, regulatory agencies do not appear concerned with the possible outcome of the exposure of corals and their algal symbionts to this metal oxide. This review compiles the published work on the toxicity of ZnO and ZnO-NPs to corals and zooxanthellae, which strongly supports the notion that zinc oxide is toxic to both corals and microalgae. In view of this, concern has been raised by the use of the “reef safe” label to promote sunscreens that lack specific organic components, however containing ZnO as the major UV filter.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68268753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230007
Roberta Beluco, E. Ionashiro, Núbia de Brito
CHARACTERIZATION OF SOLID RESIDUES THROUGH THERMAL ANALYSIS: UTILIZATION PERSPECTIVE AS FILTER MATERIAL FOR WASTEWATER TREATMENT. Metallurgical waste and vermiculite are solid residues that have potential of utilization as filtering material. Nevertheless, they are commonly discarded. These materials have chemical sites like Si-O, Si-O-Si in vermiculite or have good ionic exchange properties like iron oxide compounds that can be used in adsorption processes. When these materials are combined with a synthetic blanket (OH, C=C, CO and C-H groups), it composes a filter layer with potential to be used in wastewater treatment. In this article, these materials were chemically treated and characterized by Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and coupled TG-FTIR. The results suggest that organic compound contamination was not found after chemical treatment, which could have remained over the unity operations in the Metallurgical processes. The thermal and acid treatments influenced a major formation of iron oxide formation, but its oxidation degree (FeO, Fe2O3, or Fe2O3.FeO) were dependent on the sample granulometry. The Vermiculite shows an irreversible chemical modification after thermal treatment. The characterization of these residues shows its potential use as material in filter construction. Hence, it is fundamental to minimize the environmental impacts as well as to diminish the production costs in wastewater treatment.
{"title":"CARACTERIZAÇÃO DE RESÍDUOS SÓLIDOS INDUSTRIAIS POR ANÁLISE TÉRMICA: PERSPECTIVAS DE USO COMO MATERIAL FILTRANTE PARA ÁGUAS RESIDUÁRIAS","authors":"Roberta Beluco, E. Ionashiro, Núbia de Brito","doi":"10.21577/0100-4042.20230007","DOIUrl":"https://doi.org/10.21577/0100-4042.20230007","url":null,"abstract":"CHARACTERIZATION OF SOLID RESIDUES THROUGH THERMAL ANALYSIS: UTILIZATION PERSPECTIVE AS FILTER MATERIAL FOR WASTEWATER TREATMENT. Metallurgical waste and vermiculite are solid residues that have potential of utilization as filtering material. Nevertheless, they are commonly discarded. These materials have chemical sites like Si-O, Si-O-Si in vermiculite or have good ionic exchange properties like iron oxide compounds that can be used in adsorption processes. When these materials are combined with a synthetic blanket (OH, C=C, CO and C-H groups), it composes a filter layer with potential to be used in wastewater treatment. In this article, these materials were chemically treated and characterized by Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and coupled TG-FTIR. The results suggest that organic compound contamination was not found after chemical treatment, which could have remained over the unity operations in the Metallurgical processes. The thermal and acid treatments influenced a major formation of iron oxide formation, but its oxidation degree (FeO, Fe2O3, or Fe2O3.FeO) were dependent on the sample granulometry. The Vermiculite shows an irreversible chemical modification after thermal treatment. The characterization of these residues shows its potential use as material in filter construction. Hence, it is fundamental to minimize the environmental impacts as well as to diminish the production costs in wastewater treatment.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230013
Wei Zhang, Zhiqiang Cai, Wei Li, Qiuchen Huang, Ruonan Chen, Yiwen Li, Keyun Jin, Yi Zhao, T. Sun
This work presented a new PEG modified calix[4]arene stationary phase (C4A-PEG-2PTSC) for gas chromatographic (GC) separations. The statically coated C4A-PEG-2PTSC column exhibited moderate polarity and column efficiency of 2224 plates m-1 determined by 1-octanol at 120 oC. The results showed that the C4A-PEG-2PTSC column exhibited the good separation performance for various types of analytes containing halogenated benzenes, benzaldehydes, phenols, alcohols, anilines isomers and showed the different retention behavior with the comparative columns. Importantly, it showed the better separation capacity of toluidine and xylidine isomers than commercial HP-35 column. Moreover, it was applied in practical sample analysis to detect the content of isomer impurities. This work exhibited the good application potential of C4A-PEG-2PTSC stationary phase in GC analyses.
{"title":"SEPARATION PERFORMANCE OF PEG-LINKED CALIX[4]ARENE AS STATIONARY PHASE FOR CAPILLARY GAS CHROMATOGRAPHY","authors":"Wei Zhang, Zhiqiang Cai, Wei Li, Qiuchen Huang, Ruonan Chen, Yiwen Li, Keyun Jin, Yi Zhao, T. Sun","doi":"10.21577/0100-4042.20230013","DOIUrl":"https://doi.org/10.21577/0100-4042.20230013","url":null,"abstract":"This work presented a new PEG modified calix[4]arene stationary phase (C4A-PEG-2PTSC) for gas chromatographic (GC) separations. The statically coated C4A-PEG-2PTSC column exhibited moderate polarity and column efficiency of 2224 plates m-1 determined by 1-octanol at 120 oC. The results showed that the C4A-PEG-2PTSC column exhibited the good separation performance for various types of analytes containing halogenated benzenes, benzaldehydes, phenols, alcohols, anilines isomers and showed the different retention behavior with the comparative columns. Importantly, it showed the better separation capacity of toluidine and xylidine isomers than commercial HP-35 column. Moreover, it was applied in practical sample analysis to detect the content of isomer impurities. This work exhibited the good application potential of C4A-PEG-2PTSC stationary phase in GC analyses.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230008
R. Valero, Rafael Mori, L. Massi
CHEMISTRY IN PRIMO LEVI’S LITERATURE: PHILOSOPHICAL ASPECTS ON EXPERIMENTATION, MATTER AND THE PROFESSION OF CHEMISTRY. The Italian chemist Primo Levi (1919-1987) published a testimonial literature about the period he was captive in Auschwitz, later exploring other literary genres. In his work as a whole, the science-art relationship takes place both in terms of content (when chemistry and scientific knowledge are themes) and form (when the author appropriates the language and logic of science to communicate his experiences, especially those lived in the concentration camp). Three themes related to the chemical universe are present in Levi’s writings: experiments, man’s relationship with matter and chemistry as a work. In this article, we bring these topics closer to current discussions in the field of philosophy of chemistry. The philosophical discussion and Primo Levi’s literature converge on the understanding that experiments assumes a particular role in chemistry, that matter is a central category for this science and that the chemical profession raises ethical questions, such as those related to impacts of the incessant production of new substances.
{"title":"A QUÍMICA NA LITERATURA DE PRIMO LEVI: ASPECTOS FILOSÓFICOS SOBRE EXPERIMENTAÇÃO, MATÉRIA E OFÍCIO QUÍMICO","authors":"R. Valero, Rafael Mori, L. Massi","doi":"10.21577/0100-4042.20230008","DOIUrl":"https://doi.org/10.21577/0100-4042.20230008","url":null,"abstract":"CHEMISTRY IN PRIMO LEVI’S LITERATURE: PHILOSOPHICAL ASPECTS ON EXPERIMENTATION, MATTER AND THE PROFESSION OF CHEMISTRY. The Italian chemist Primo Levi (1919-1987) published a testimonial literature about the period he was captive in Auschwitz, later exploring other literary genres. In his work as a whole, the science-art relationship takes place both in terms of content (when chemistry and scientific knowledge are themes) and form (when the author appropriates the language and logic of science to communicate his experiences, especially those lived in the concentration camp). Three themes related to the chemical universe are present in Levi’s writings: experiments, man’s relationship with matter and chemistry as a work. In this article, we bring these topics closer to current discussions in the field of philosophy of chemistry. The philosophical discussion and Primo Levi’s literature converge on the understanding that experiments assumes a particular role in chemistry, that matter is a central category for this science and that the chemical profession raises ethical questions, such as those related to impacts of the incessant production of new substances.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.21577/0100-4042.20230005
M. Clemente, Heloisa Silva, Nathan Silva, Júlia Campos, E. D. De Sousa, H. Silva, A. Mantovani, Karina B. Angilelli, D. Borsato
The simultaneous diffusion of inorganic components in the olive pulp in wet brine was modeled based on Fick’s generalized 2nd Law and simulated using the finite element method. The main and crossed diffusion coefficients, the film coefficient and the Biot number were determined, with the application of the simplex optimization method, through the minimization of the percentage errors. The errors between the simulated and experimental data were 5.35% for NaCl and 4.77% for KCl and the adjusted main diffusion coefficients were 0.4358 × 10-12 m2 s-1 for NaCl and 0.5408 × 10-12 m2 s-1 for KCl. The system developed to simulate diffusion allows the control and modulation of the salts content that diffuses through the olive pulp.
{"title":"SIMULATION OF THE DIFFUSION PROCESS OF NaCl AND KCl IN OLIVE PULP USING THE FINITE ELEMENT METHOD","authors":"M. Clemente, Heloisa Silva, Nathan Silva, Júlia Campos, E. D. De Sousa, H. Silva, A. Mantovani, Karina B. Angilelli, D. Borsato","doi":"10.21577/0100-4042.20230005","DOIUrl":"https://doi.org/10.21577/0100-4042.20230005","url":null,"abstract":"The simultaneous diffusion of inorganic components in the olive pulp in wet brine was modeled based on Fick’s generalized 2nd Law and simulated using the finite element method. The main and crossed diffusion coefficients, the film coefficient and the Biot number were determined, with the application of the simplex optimization method, through the minimization of the percentage errors. The errors between the simulated and experimental data were 5.35% for NaCl and 4.77% for KCl and the adjusted main diffusion coefficients were 0.4358 × 10-12 m2 s-1 for NaCl and 0.5408 × 10-12 m2 s-1 for KCl. The system developed to simulate diffusion allows the control and modulation of the salts content that diffuses through the olive pulp.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-28DOI: 10.21577/0100-4042.20170510
F. Freitas, S. Pilling
Here we present experimental results on the irradiation of ethanol ice (CH3CH2OH) by broadband soft X-rays to simulate the effect processing of organic-rich astrophysical ices by space radiation. This molecule was detected in the interstellar medium in molecular clouds like Sagittarius B2 and towards nebulas like Orion KL. The experiments were performed at the Brazilian Synchrotron Facility LNLS/CNPEM, at Campinas, SP. The frozen sample was analyzed in-situ by infrared spectroscopy (IR) in a simulated astrophysical environment at different radiation fluences. The results show the formation of several new molecular species such as CO2, CO, H2O, CH4, CH3(CO)CH3 (acetone), and CH3COOH (acetic acid). We determined the effective destruction cross-section of ethanol (~1×10-18 cm2) and the formation cross-sections of the daughter species with values between 0.5 to 3.4×10-18 cm2. The chemical equilibrium phase of ice was characterized and desorption yield induced by X-rays was determined (0.13 molecules photon-1). The result helps us to understand the photolysis induced by X-rays in organic-rich ices in space environments.
{"title":"LABORATORY INVESTIGATION OF X-RAY PHOTOLYSIS OF METHANOL ICE AND ITS IMPLICATION ON ASTROPHYSICAL ENVIRONMENTS","authors":"F. Freitas, S. Pilling","doi":"10.21577/0100-4042.20170510","DOIUrl":"https://doi.org/10.21577/0100-4042.20170510","url":null,"abstract":"Here we present experimental results on the irradiation of ethanol ice (CH3CH2OH) by broadband soft X-rays to simulate the effect processing of organic-rich astrophysical ices by space radiation. This molecule was detected in the interstellar medium in molecular clouds like Sagittarius B2 and towards nebulas like Orion KL. The experiments were performed at the Brazilian Synchrotron Facility LNLS/CNPEM, at Campinas, SP. The frozen sample was analyzed in-situ by infrared spectroscopy (IR) in a simulated astrophysical environment at different radiation fluences. The results show the formation of several new molecular species such as CO2, CO, H2O, CH4, CH3(CO)CH3 (acetone), and CH3COOH (acetic acid). We determined the effective destruction cross-section of ethanol (~1×10-18 cm2) and the formation cross-sections of the daughter species with values between 0.5 to 3.4×10-18 cm2. The chemical equilibrium phase of ice was characterized and desorption yield induced by X-rays was determined (0.13 molecules photon-1). The result helps us to understand the photolysis induced by X-rays in organic-rich ices in space environments.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46953367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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