Pub Date : 2023-04-13DOI: 10.17807/orbital.v15i1.18047
Mateus Ladeira, M. Miranda
The Pre-exposure Prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) infection consists in using antiretroviral medicine before sexual exposure to the virus to decrease probability of infection. The PrEP is capable of preventing the virus infection and promoting a healthier sexual life. Brazil has been a reference in HIV treatment not only because it was the first country in Latin America to offer free antiretroviral treatment to virus carriers but also because it participated in the Initiative in Pre-exposure Prophylaxis (iPrEP), a study that was carried out in several countries worldwide and proved effectiveness of the PrEP. Medication distributed by the Brazilian Public Health System (SUS) is quite unknown to the population. To mitigate current proliferation of sexually transmitted diseases (STDs) and increase in pregnancy cases among adolescents, sexual orientation has been intensified in schools and, thus, it has also become their responsibility, rather than parents’ responsibility alone. Therefore, this study aimed at carrying out dynamic and dialogic interventions about the PrEP in classes taught to High School seniors who attend technical courses in Commerce and in Development of Digital Games at the Instituto Federal do Triângulo Mineiro - Campus Uberlândia Centro, Uberlândia, Minas Gerais (MG), Brazil. A dialogical Chemistry class was taught to show students several images and chemical structures of active ingredients found in the medication (PrEP). Besides, students answered a questionnaire with open questions anonymously to evaluate the effect of the class on their learning about sexual education, HIV/AIDS and, mainly, the PrEP. Students showed much interest in the tasks and interacted positively. Results of the questionnaire enabled to observe students’ increase in knowledge about the PrEP. In sum, this study enabled the PrEP to be better disseminated, since doubts were mitigated.
预防人类免疫缺陷病毒(HIV)感染的暴露前预防(PrEP)包括在与病毒发生性接触之前使用抗逆转录病毒药物，以减少感染的可能性。PrEP能够预防病毒感染，促进更健康的性生活。巴西在艾滋病毒治疗方面一直是一个参考，不仅因为它是拉丁美洲第一个向病毒携带者提供免费抗逆转录病毒治疗的国家，还因为它参与了暴露前预防倡议(iPrEP)，这是一项在全球几个国家开展的研究，证明了PrEP的有效性。巴西公共卫生系统(SUS)分发的药物对人口来说是相当陌生的。为了减轻目前性传播疾病的扩散和青少年怀孕案例的增加，学校加强了性取向教育，因此性取向也成为学生的责任，而不仅仅是家长的责任。因此，本研究旨在对在巴西米纳斯吉拉斯州联邦学院(Instituto Federal do tringulo Mineiro)就读商业和数字游戏开发技术课程的高中毕业生进行动态和对话干预。一门对话化学课向学生展示了药物(PrEP)中有效成分的几幅图像和化学结构。此外，学生们还以匿名方式回答了一份开放性问题问卷，以评估课程对他们在性教育、艾滋病毒/艾滋病以及主要是PrEP方面的学习效果。学生们对任务表现出浓厚的兴趣，并积极互动。问卷调查的结果可以观察到学生对PrEP知识的增加。总之，本研究可以更好地传播PrEP，因为减轻了疑虑。
{"title":"Chemistry of Pre-exposure Prophylaxis (PrEP) and Brazil’s Protagonism in the Fight Against HIV/AIDS: Exploring the Theme with High School Seniors","authors":"Mateus Ladeira, M. Miranda","doi":"10.17807/orbital.v15i1.18047","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.18047","url":null,"abstract":"The Pre-exposure Prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) infection consists in using antiretroviral medicine before sexual exposure to the virus to decrease probability of infection. The PrEP is capable of preventing the virus infection and promoting a healthier sexual life. Brazil has been a reference in HIV treatment not only because it was the first country in Latin America to offer free antiretroviral treatment to virus carriers but also because it participated in the Initiative in Pre-exposure Prophylaxis (iPrEP), a study that was carried out in several countries worldwide and proved effectiveness of the PrEP. Medication distributed by the Brazilian Public Health System (SUS) is quite unknown to the population. To mitigate current proliferation of sexually transmitted diseases (STDs) and increase in pregnancy cases among adolescents, sexual orientation has been intensified in schools and, thus, it has also become their responsibility, rather than parents’ responsibility alone. Therefore, this study aimed at carrying out dynamic and dialogic interventions about the PrEP in classes taught to High School seniors who attend technical courses in Commerce and in Development of Digital Games at the Instituto Federal do Triângulo Mineiro - Campus Uberlândia Centro, Uberlândia, Minas Gerais (MG), Brazil. A dialogical Chemistry class was taught to show students several images and chemical structures of active ingredients found in the medication (PrEP). Besides, students answered a questionnaire with open questions anonymously to evaluate the effect of the class on their learning about sexual education, HIV/AIDS and, mainly, the PrEP. Students showed much interest in the tasks and interacted positively. Results of the questionnaire enabled to observe students’ increase in knowledge about the PrEP. In sum, this study enabled the PrEP to be better disseminated, since doubts were mitigated.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47057396","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 : 2023-04-12DOI: 10.17807/orbital.v15i1.17992
Ariane Aparecida de Lima, Lucas Aparecido Bittencourt, Guilherme José Turcatel Alves, G. Tractz, P. Rodrigues, Cynthia Beatriz Fürstenberger
To fabricate a hydrophobic coating using the sol-gel method (Pechini), an experimental design using the drying time and chemicals ratio as variables was developed. The coating was deposited on an aluminum substrate (AA6061-T6) treated by acid solution or anodization method. The surface wettability was measured using a goniometric instrument. Coatings were fabricated using different numbers of layers, heating rates, and drying temperatures, and their morphologies were observed using visual analysis and scanning electron microscopy. The use of anodization treatment with a furnace ramp of 1 °C min-1, a drying temperature of 220 °C ± 10 °C, and single-layer application, produced a coating free of visible flaws and apparent damage. The coating was obtained with a 15:1 glycerin:citric acid ratio and sample pre-polymerization in the drying oven for 1 hour at 100 °C resulted in the highest contact angle, 62° ± 2°, which meets the ASTM D-7334-08 standard for a hydrophobic surface.
{"title":"Optimization of Hydrophobic Coating Production by Pechini Method on Modified Aluminum Surface","authors":"Ariane Aparecida de Lima, Lucas Aparecido Bittencourt, Guilherme José Turcatel Alves, G. Tractz, P. Rodrigues, Cynthia Beatriz Fürstenberger","doi":"10.17807/orbital.v15i1.17992","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.17992","url":null,"abstract":"To fabricate a hydrophobic coating using the sol-gel method (Pechini), an experimental design using the drying time and chemicals ratio as variables was developed. The coating was deposited on an aluminum substrate (AA6061-T6) treated by acid solution or anodization method. The surface wettability was measured using a goniometric instrument. Coatings were fabricated using different numbers of layers, heating rates, and drying temperatures, and their morphologies were observed using visual analysis and scanning electron microscopy. The use of anodization treatment with a furnace ramp of 1 °C min-1, a drying temperature of 220 °C ± 10 °C, and single-layer application, produced a coating free of visible flaws and apparent damage. The coating was obtained with a 15:1 glycerin:citric acid ratio and sample pre-polymerization in the drying oven for 1 hour at 100 °C resulted in the highest contact angle, 62° ± 2°, which meets the ASTM D-7334-08 standard for a hydrophobic surface.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48278853","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 : 2023-04-12DOI: 10.17807/orbital.v15i1.17525
U. Pandey, C. Sharma
In this research, the influence of deposition current density on the properties of nickel-Graphene oxide/alumina coatings produced by electrodeposition was examined. Nickel matrix composite coatings with graphene oxide doped Alumina (GO-Al2O3) particles were prepared via electrodeposition. When embedding GO-Al2O3 particles in the Ni matrix, remarkable anti-corrosion properties are anticipated due to the outstanding mechanical properties of GO and Al2O3. The structure, content, and morphology of GO, GO-Al2O3, and coatings deposited at various current densities were determined using X-ray diffraction, Fourier transforms infrared spectroscopy, Field emission Scanning electron microscopy, and energy-dispersive X-ray spectroscopy. GO-doped alumina particles were successfully incorporated into the matrix of nickel, according to the findings. Porosity measurement and cross-sectional thickness were also investigated at various current densities. Potentiodynamic polarization testing and electrochemical impedance spectroscopy were used to study the coatings' corrosion-resistant characteristics. According to the findings, coatings developed at high current densities, such as 30 mA cm-2, are porous and not uniform in nature. Furthermore, at high current densities, the content of GO and Alumina is reduced, resulting in a decrease in mechanical and corrosion resistance. Due to its less porous and uniformly formed coating, 10 mA cm-2 was the optimum current density for achieving the most desirable features.
本研究考察了沉积电流密度对电沉积镍-氧化石墨烯/氧化铝涂层性能的影响。采用电沉积法制备了氧化石墨烯掺杂氧化铝(GO-Al2O3)颗粒的镍基复合涂层。在Ni基体中嵌入GO-Al2O3颗粒，由于GO和Al2O3优异的力学性能，预期具有显著的抗腐蚀性能。利用x射线衍射、傅里叶变换红外光谱、场发射扫描电子显微镜和能量色散x射线光谱分析了不同电流密度下氧化石墨烯、氧化石墨烯- al2o3和涂层的结构、含量和形貌。根据研究结果，氧化石墨烯掺杂的氧化铝颗粒被成功地结合到镍基体中。孔隙度测量和截面厚度也在不同的电流密度下进行了研究。采用动电位极化测试和电化学阻抗谱技术研究了涂层的耐腐蚀性能。根据研究结果，在高电流密度(如30 mA cm-2)下开发的涂层具有多孔性，并且性质不均匀。此外，在高电流密度下，氧化石墨烯和氧化铝的含量减少，导致机械和耐腐蚀性下降。由于其较少的多孔性和均匀形成的涂层，10 mA cm-2是实现最理想特性的最佳电流密度。
{"title":"Advancement of Novel Graphene Oxide Embedded Alumina Nickel Composite Coating Developed at Various Current Densities to Evaluate Corrosion Resistance","authors":"U. Pandey, C. Sharma","doi":"10.17807/orbital.v15i1.17525","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.17525","url":null,"abstract":"In this research, the influence of deposition current density on the properties of nickel-Graphene oxide/alumina coatings produced by electrodeposition was examined. Nickel matrix composite coatings with graphene oxide doped Alumina (GO-Al2O3) particles were prepared via electrodeposition. When embedding GO-Al2O3 particles in the Ni matrix, remarkable anti-corrosion properties are anticipated due to the outstanding mechanical properties of GO and Al2O3. The structure, content, and morphology of GO, GO-Al2O3, and coatings deposited at various current densities were determined using X-ray diffraction, Fourier transforms infrared spectroscopy, Field emission Scanning electron microscopy, and energy-dispersive X-ray spectroscopy. GO-doped alumina particles were successfully incorporated into the matrix of nickel, according to the findings. Porosity measurement and cross-sectional thickness were also investigated at various current densities. Potentiodynamic polarization testing and electrochemical impedance spectroscopy were used to study the coatings' corrosion-resistant characteristics. According to the findings, coatings developed at high current densities, such as 30 mA cm-2, are porous and not uniform in nature. Furthermore, at high current densities, the content of GO and Alumina is reduced, resulting in a decrease in mechanical and corrosion resistance. Due to its less porous and uniformly formed coating, 10 mA cm-2 was the optimum current density for achieving the most desirable features. \u0000 ","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43813660","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 : 2023-04-12DOI: 10.17807/orbital.v15i1.17592
S. Arora, Kalpana Tirpude, Pallavi Rushiya, Nidhi Sapkal, Subhash Yende, Abhay Ittadwar, Sapan Shah
In present study, the inhibitory potential of Neolamarckia cadamba phytoconstituents was investigated against SARS-CoV-2 3CL protease (3CL pro) (PDB ID: 6M2N). Molecular docking was analyzed using AutoDock Vina software by setting the grid parameter as X= -33.163, Y= -65.074 and Z= 41.434 with dimensions of the grid box 25 × 25 × 25 Å. Remdesivir was taken as the standard for comparative analysis along with inhibitor 5, 6, 7-trihydroxy-2-phenyl-4H-chromen-4-one. Furthermore, the exploration of 2 D Hydrogen-bond interactions was performed by Biovia Discovery Studio 4.5 program to identify the interactions between an amino acid of target and ligand followed by assessment of physicochemical properties using Lipinski’s rule and Swiss ADME database. The decent bonding scores of secondary metabolites owing to hydrogen bonding with catalytic residues suggest the effectiveness of these phytochemicals towards 3CLpro. The results are further consolidated positively by Lipinski’s rule and Swiss ADME prediction. Thus reasonably, observations with docking studies suggest possibility of phytochemicals from Neolamarckia cadamba to inhibit the 3CLpro and consequently would be explored further as agents for preventing COVID-19.
{"title":"Investigation of Neolamarckia cadamba phytoconstituents against SARS-CoV-2 3CL Pro: An In-Silico Approach","authors":"S. Arora, Kalpana Tirpude, Pallavi Rushiya, Nidhi Sapkal, Subhash Yende, Abhay Ittadwar, Sapan Shah","doi":"10.17807/orbital.v15i1.17592","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.17592","url":null,"abstract":"In present study, the inhibitory potential of Neolamarckia cadamba phytoconstituents was investigated against SARS-CoV-2 3CL protease (3CL pro) (PDB ID: 6M2N). Molecular docking was analyzed using AutoDock Vina software by setting the grid parameter as X= -33.163, Y= -65.074 and Z= 41.434 with dimensions of the grid box 25 × 25 × 25 Å. Remdesivir was taken as the standard for comparative analysis along with inhibitor 5, 6, 7-trihydroxy-2-phenyl-4H-chromen-4-one. Furthermore, the exploration of 2 D Hydrogen-bond interactions was performed by Biovia Discovery Studio 4.5 program to identify the interactions between an amino acid of target and ligand followed by assessment of physicochemical properties using Lipinski’s rule and Swiss ADME database. The decent bonding scores of secondary metabolites owing to hydrogen bonding with catalytic residues suggest the effectiveness of these phytochemicals towards 3CLpro. The results are further consolidated positively by Lipinski’s rule and Swiss ADME prediction. Thus reasonably, observations with docking studies suggest possibility of phytochemicals from Neolamarckia cadamba to inhibit the 3CLpro and consequently would be explored further as agents for preventing COVID-19.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67424815","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 : 2023-04-06DOI: 10.17807/orbital.v15i1.18012
Volodymyr Tkach, M. Kucher, M. Kushnir, Y. Ivanushko, Y. Akinay, Necdet Karakoyun, P. Yagodynets, Z. Kormosh
The possibility of psilocin electrochemical determination over cobalt (III) oxyhydroxide-modified anode is evaluated from the mathematical point of view. Psilocin is thereby oxidized yielding either micro- or macromolecular product, being both of them important for the economical and green conducting polymer composite for electrocatalysis, electroanalysis and energy conversion. The analysis of the correspondent mathematical model confirms, that, despite of the high probability of the oscillatory behavior, the electrochemical process is efficient from both analytical and synthetical point of view.
{"title":"The Theoretical Description for Psilocin Electrochemical Determination over Cobalt Oxyhydroxide","authors":"Volodymyr Tkach, M. Kucher, M. Kushnir, Y. Ivanushko, Y. Akinay, Necdet Karakoyun, P. Yagodynets, Z. Kormosh","doi":"10.17807/orbital.v15i1.18012","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.18012","url":null,"abstract":"The possibility of psilocin electrochemical determination over cobalt (III) oxyhydroxide-modified anode is evaluated from the mathematical point of view. Psilocin is thereby oxidized yielding either micro- or macromolecular product, being both of them important for the economical and green conducting polymer composite for electrocatalysis, electroanalysis and energy conversion. The analysis of the correspondent mathematical model confirms, that, despite of the high probability of the oscillatory behavior, the electrochemical process is efficient from both analytical and synthetical point of view.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43309222","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 : 2023-04-06DOI: 10.17807/orbital.v15i1.17021
I. Moro, F. A. Carvalho, Thais Fernanda Moreira, Felipe de Oliveira Souza, Alexander Alves da Silva, F. Politi, C. P. Soares, A. G. Santos
This study evaluated the potential of Baccharis trimera essential oil (EO) and its components in cancer therapy through the application of cytotoxicity and cell death assays. Using gas chromatography analysis, the major components of the aerial parts of the essential oil were identified as (E)-caryophyllene (18.9%), bicyclogermacrene (15.6%), and germacrene D (10.5%). Baccharis trimera essential oil (5.8 μg/mL) and α-humulene (7.8 μg/mL) presented strong cytotoxic activity, while (E)-caryophyllene (11.5 μg/mL) and caryophyllene oxide (> 100.0 μg/mL) showed moderate and low activities, respectively, against MCF-7 cell lines. Against HepG2 cell lines, B. trimera essential oil (10.4 μg/mL), α-humulene (17.1 μg/mL), and caryophyllene oxide (19.4 μg/mL) exhibited moderate activity, while (E)-caryophyllene (52.3 μg/mL) displayed low activity against HepG2 cell lines. The selectivity index values of EO (MCF-7 and HepG2), α-humulene and (E)-caryophyllene (MCF-7), and caryophyllene oxide (HepG2) were found between 1.1 and 2.8, compared with MCF-10A cells. The annexin-V and Hoechst / propidium iodide assays performed with essential oil, (E)-caryophyllene, α-humulene, and caryophyllene oxide showed apoptosis and necrosis mechanisms for all cell lines. Based on these findings, B. trimera essential oil and its components can be considered as potential therapeutic agents against cancer.
{"title":"Cytotoxic Activity of Baccharis trimera (Less.) DC. Essential Oil in Tumor Cell Lines and its Role in Associated Death Mechanisms","authors":"I. Moro, F. A. Carvalho, Thais Fernanda Moreira, Felipe de Oliveira Souza, Alexander Alves da Silva, F. Politi, C. P. Soares, A. G. Santos","doi":"10.17807/orbital.v15i1.17021","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.17021","url":null,"abstract":"This study evaluated the potential of Baccharis trimera essential oil (EO) and its components in cancer therapy through the application of cytotoxicity and cell death assays. Using gas chromatography analysis, the major components of the aerial parts of the essential oil were identified as (E)-caryophyllene (18.9%), bicyclogermacrene (15.6%), and germacrene D (10.5%). Baccharis trimera essential oil (5.8 μg/mL) and α-humulene (7.8 μg/mL) presented strong cytotoxic activity, while (E)-caryophyllene (11.5 μg/mL) and caryophyllene oxide (> 100.0 μg/mL) showed moderate and low activities, respectively, against MCF-7 cell lines. Against HepG2 cell lines, B. trimera essential oil (10.4 μg/mL), α-humulene (17.1 μg/mL), and caryophyllene oxide (19.4 μg/mL) exhibited moderate activity, while (E)-caryophyllene (52.3 μg/mL) displayed low activity against HepG2 cell lines. The selectivity index values of EO (MCF-7 and HepG2), α-humulene and (E)-caryophyllene (MCF-7), and caryophyllene oxide (HepG2) were found between 1.1 and 2.8, compared with MCF-10A cells. The annexin-V and Hoechst / propidium iodide assays performed with essential oil, (E)-caryophyllene, α-humulene, and caryophyllene oxide showed apoptosis and necrosis mechanisms for all cell lines. Based on these findings, B. trimera essential oil and its components can be considered as potential therapeutic agents against cancer.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45218372","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 : 2023-04-05DOI: 10.17807/orbital.v15i1.16470
D. Barrios, C. Alvarez
Smart windows based on suspended particle devices (SPDs) are able to switch optically from dark to clear visual appearance when applying an AC electrical signal. This effect is due to light absorbing nanoparticles that get aligned by the applied voltage. The sandwich structure of an SPD consists of several layers and includes two outer glass substrates, each one covered on its inwards-facing side with a transparent conducting thin layer surrounding the centrally positioned SPD active layer. A knowledge of the optical constants of each layer—i.e., the complex refractive index, including its real and imaginary (absorption) parts—is a key in the design of the visual appearance of the SPD window and is a useful tool to determine the optimum thickness of the active layer.
{"title":"Spectral Voltage Contour Plots of Optical Constants and Interface Parameters of the Active Layer of a Multilayer Structure Suspended Particle Device Smart Window from Clear on to Dark off States","authors":"D. Barrios, C. Alvarez","doi":"10.17807/orbital.v15i1.16470","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.16470","url":null,"abstract":"Smart windows based on suspended particle devices (SPDs) are able to switch optically from dark to clear visual appearance when applying an AC electrical signal. This effect is due to light absorbing nanoparticles that get aligned by the applied voltage. The sandwich structure of an SPD consists of several layers and includes two outer glass substrates, each one covered on its inwards-facing side with a transparent conducting thin layer surrounding the centrally positioned SPD active layer. A knowledge of the optical constants of each layer—i.e., the complex refractive index, including its real and imaginary (absorption) parts—is a key in the design of the visual appearance of the SPD window and is a useful tool to determine the optimum thickness of the active layer.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44866805","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 : 2023-04-05DOI: 10.17807/orbital.v15i1.16398
Claudio Yamamoto Morassuti, S. Lima, L. H. da Cunha Andrade
Here, we report the use of fluorescence spectroscopy for the identification of lubricant oils used in reciprocating compressors, and the use of silica gel as an adsorbent to capture lubricant oil vapors. The silica gel was tested for adsorption of lubricant oil vapors, by heating the samples at 200°C, the emission spectrum of the lubricant oils is observed on the silica gel layer, over 20 min of heating. The spectrum of the lubricant oils over the silica gel layer presents a redshift, an indication of the degradation effect. In order to investigate this effect on the optical properties, we conducted an experiment by heating the samples at (130 ± 4) °C, and collected at different times. The MID-infrared absorption of the samples presents bands of oxygen-containing groups at 1010 and 1050 cm-1, and NIR infrared absorption measurements at 3444 cm-1 show an increase in the hydroperoxide band during the degradation time. These two results indicate that the oxidation process is associated with the observed redshift of the absorption and emission bands in lubricant oils and over the adsorbent layer.
{"title":"Fluorescence Spectroscopy and Silica Gel Applied as a Tool for Capture and Detection of Compressor Lubricant Oils","authors":"Claudio Yamamoto Morassuti, S. Lima, L. H. da Cunha Andrade","doi":"10.17807/orbital.v15i1.16398","DOIUrl":"https://doi.org/10.17807/orbital.v15i1.16398","url":null,"abstract":"Here, we report the use of fluorescence spectroscopy for the identification of lubricant oils used in reciprocating compressors, and the use of silica gel as an adsorbent to capture lubricant oil vapors. The silica gel was tested for adsorption of lubricant oil vapors, by heating the samples at 200°C, the emission spectrum of the lubricant oils is observed on the silica gel layer, over 20 min of heating. The spectrum of the lubricant oils over the silica gel layer presents a redshift, an indication of the degradation effect. In order to investigate this effect on the optical properties, we conducted an experiment by heating the samples at (130 ± 4) °C, and collected at different times. The MID-infrared absorption of the samples presents bands of oxygen-containing groups at 1010 and 1050 cm-1, and NIR infrared absorption measurements at 3444 cm-1 show an increase in the hydroperoxide band during the degradation time. These two results indicate that the oxidation process is associated with the observed redshift of the absorption and emission bands in lubricant oils and over the adsorbent layer.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47836333","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 : 2023-01-03DOI: 10.17807/orbital.v14i4.16294
Deni Ainur Rokhim, A. Atikah, Isma Yanti Vitarisma, S. Rahayu, M. Muntholib
Problem-solving is one of the abilities that a student must-have in the 21st century. This is because students' ability to solve problems is expected to increase their competence of higher-order thinking skills (HOTS). Problem-solving ability can be improved in several ways for example, the use of a certain instructional model, worksheets, and assessment or assessment based on problem-solving. This study aimed to develop and implement structured problem-solving assessment with the IDEAL model on acid-base materials, salt hydrolysis, buffer solutions, and acid-base titrations to examine students' problem-solving abilities. The instrument development model used adapts the ADDIE model with four steps, namely analysis, planning, development, and implementation. The research sample were 34 high school students in grade 11 in Sidoarjo, East Java. The result is that the problem-solving ability with the lowest percentage are in the acid-base titration material for the Act on strategy indicator at 27.21%, while the highest percentage of skills are found in the buffer solution material for the Explore solution indicator at 89.5%. This study implies that the test instrument for further research is to measure students' ability to solve structured problems with the IDEAL model on acid and base. This study implies that the test instrument for further research measures students' ability to solve structured problems with the IDEAL model on acid-base, salt hydrolysis, buffer solution, and acid titration. So that the problem solving process with the integration of problem solving problems can improve students' critical thinking.
{"title":"Assessment of High School Students’ Ability to Solve Structured Problems with Ideal Model on Acid-Base","authors":"Deni Ainur Rokhim, A. Atikah, Isma Yanti Vitarisma, S. Rahayu, M. Muntholib","doi":"10.17807/orbital.v14i4.16294","DOIUrl":"https://doi.org/10.17807/orbital.v14i4.16294","url":null,"abstract":"Problem-solving is one of the abilities that a student must-have in the 21st century. This is because students' ability to solve problems is expected to increase their competence of higher-order thinking skills (HOTS). Problem-solving ability can be improved in several ways for example, the use of a certain instructional model, worksheets, and assessment or assessment based on problem-solving. This study aimed to develop and implement structured problem-solving assessment with the IDEAL model on acid-base materials, salt hydrolysis, buffer solutions, and acid-base titrations to examine students' problem-solving abilities. The instrument development model used adapts the ADDIE model with four steps, namely analysis, planning, development, and implementation. The research sample were 34 high school students in grade 11 in Sidoarjo, East Java. The result is that the problem-solving ability with the lowest percentage are in the acid-base titration material for the Act on strategy indicator at 27.21%, while the highest percentage of skills are found in the buffer solution material for the Explore solution indicator at 89.5%. This study implies that the test instrument for further research is to measure students' ability to solve structured problems with the IDEAL model on acid and base. This study implies that the test instrument for further research measures students' ability to solve structured problems with the IDEAL model on acid-base, salt hydrolysis, buffer solution, and acid titration. So that the problem solving process with the integration of problem solving problems can improve students' critical thinking.","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43931650","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 : 2023-01-03DOI: 10.17807/orbital.v14i4.17209
J. Moreto, W. B. Bose Filho
This work aims to evaluate the effect of localized corrosion on the fatigue crack growth (FCG) resistance of the 7081-T73511 aluminium alloy. The understanding of this complex combined process was explained by the dissolution of adjacent 7081-T73511 aluminium matrix promoted by the Al7Cu2Fe second-phase particle and the crack tip interaction time with the aggressive medium. Fracture surfaces produced in air and in sea water fog at the testing conditions applied here, basically present the same appearance, with a transgranular, cleavage-like cracking mode for 8
{"title":"Recent Studies of Corrosion - Fatigue Crack Growth on the 7081-T73511 Aluminium Alloy","authors":"J. Moreto, W. B. Bose Filho","doi":"10.17807/orbital.v14i4.17209","DOIUrl":"https://doi.org/10.17807/orbital.v14i4.17209","url":null,"abstract":"This work aims to evaluate the effect of localized corrosion on the fatigue crack growth (FCG) resistance of the 7081-T73511 aluminium alloy. The understanding of this complex combined process was explained by the dissolution of adjacent 7081-T73511 aluminium matrix promoted by the Al7Cu2Fe second-phase particle and the crack tip interaction time with the aggressive medium. Fracture surfaces produced in air and in sea water fog at the testing conditions applied here, basically present the same appearance, with a transgranular, cleavage-like cracking mode for 8","PeriodicalId":19680,"journal":{"name":"Orbital: The Electronic Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44694293","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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