Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420230851
Ana Carolina F Figueiredo, Kely V DE Souza
Textile industries stand out as one of the main polluters of water resources, generating large amounts of liquid effluents with variable composition and intense coloration. The objective of this work is the integration of the reductive process using commercial steel wool, combined with oxidative processes, in the treatment of textile effluent. The effect of the variables of the reductive process were studied using a 32 factorial design. After 30 minutes, the reductive process allowed a reduction of 68% COD, 46% TOC, 62% true color and 72% of total phenols, but showed an increase in color apparent and turbidity, due to the iron species formed by the oxidation of steel wool during the process. With the combined process using sunlight, the reduction was 73% COD, 50% TOC, 97% phenols, 93% true color and 48% apparent color. With artificial light, the reduction was 94% COD, 63% TOC, 95% phenols, 98% true color and 65% apparent color. The evaluation of the acute toxicity against Daphnia magna indicated that after the proposed treatments, the effluent did not present toxicity or the toxicity was reduced. It is concluded that the combined process can be considered an efficient alternative for the treatment of textile effluent.
{"title":"Textile effluent treatment by reductive process using commercial steel wool followed by oxidative process.","authors":"Ana Carolina F Figueiredo, Kely V DE Souza","doi":"10.1590/0001-3765202420230851","DOIUrl":"https://doi.org/10.1590/0001-3765202420230851","url":null,"abstract":"<p><p>Textile industries stand out as one of the main polluters of water resources, generating large amounts of liquid effluents with variable composition and intense coloration. The objective of this work is the integration of the reductive process using commercial steel wool, combined with oxidative processes, in the treatment of textile effluent. The effect of the variables of the reductive process were studied using a 32 factorial design. After 30 minutes, the reductive process allowed a reduction of 68% COD, 46% TOC, 62% true color and 72% of total phenols, but showed an increase in color apparent and turbidity, due to the iron species formed by the oxidation of steel wool during the process. With the combined process using sunlight, the reduction was 73% COD, 50% TOC, 97% phenols, 93% true color and 48% apparent color. With artificial light, the reduction was 94% COD, 63% TOC, 95% phenols, 98% true color and 65% apparent color. The evaluation of the acute toxicity against Daphnia magna indicated that after the proposed treatments, the effluent did not present toxicity or the toxicity was reduced. It is concluded that the combined process can be considered an efficient alternative for the treatment of textile effluent.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420230724
Caik O DE Miranda, Elias DE Lima Neto, Carlos Ernesto G R Schaefer
Antarctica represents an isolated continent devoted to conservation and scientific research, although it accumulates records of increasing anthropic contamination. The historical continued use of fuel for power generation in Antarctic settlements is a potential source of toxic elements to the soil. We investigate Cd, Cr, Cu, Mn, Ni, Pb, V and Zn levels in surface soils in the vicinity of the Henryk Arctowski Antarctic Station, aiming to identify anthropic effects on their local pedochemical variability. Pollution indices were used and compared to evaluate possible cumulative anthropic impacts, whereas correlation analyzes were explored to identify potential sources of contamination. High concentrations of Pb and Zn were locally observed near fuel tanks and machinery facilities. Correlation and principal component analysis suggest that old fuel tanks, vehicle traffic and machinery disturbance are key, and contrasting, sources of contamination. Among the eight indices we compared, Enrichment Factor and Modified Degree of Contamination were chosen, showing very high enrichment for Pb and moderate for Zn. All other elements presented minimal or null enrichment. The evidence of potentially toxic elements enrichment on Antarctic soils associated with the long-term occupation of Antarctic research stations highlights the need for further monitoring and mitigation measures, especially in energy-generating systems.
{"title":"Anthropogenic effect on the pedochemical variability of potentially toxic elements at the vicinity of an Antarctic research station.","authors":"Caik O DE Miranda, Elias DE Lima Neto, Carlos Ernesto G R Schaefer","doi":"10.1590/0001-3765202420230724","DOIUrl":"https://doi.org/10.1590/0001-3765202420230724","url":null,"abstract":"<p><p>Antarctica represents an isolated continent devoted to conservation and scientific research, although it accumulates records of increasing anthropic contamination. The historical continued use of fuel for power generation in Antarctic settlements is a potential source of toxic elements to the soil. We investigate Cd, Cr, Cu, Mn, Ni, Pb, V and Zn levels in surface soils in the vicinity of the Henryk Arctowski Antarctic Station, aiming to identify anthropic effects on their local pedochemical variability. Pollution indices were used and compared to evaluate possible cumulative anthropic impacts, whereas correlation analyzes were explored to identify potential sources of contamination. High concentrations of Pb and Zn were locally observed near fuel tanks and machinery facilities. Correlation and principal component analysis suggest that old fuel tanks, vehicle traffic and machinery disturbance are key, and contrasting, sources of contamination. Among the eight indices we compared, Enrichment Factor and Modified Degree of Contamination were chosen, showing very high enrichment for Pb and moderate for Zn. All other elements presented minimal or null enrichment. The evidence of potentially toxic elements enrichment on Antarctic soils associated with the long-term occupation of Antarctic research stations highlights the need for further monitoring and mitigation measures, especially in energy-generating systems.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420231140
Bernardo Baldisserotto, Vinícius M Neves, Valderi L Dressler, Cristiano N Rosa, Ulisses F Bremer, Waterloo Pereira Filho
The aim of this study is to analyze the waterborne metal levels in four lakes (one endorheic and three exorheic) of Harmony Point, Nelson Island, Antarctica. Water samples were analyzed by using a quadrupole type inductively coupled plasma mass spectrometer and an inductively coupled plasma optical emission spectrometer. The levels of As, Cu, Mn, Mo, and V were significantly lower and those of Cr, Mg, Na, and Sr were significantly higher in the endorheic lake than in the other lakes. Most water samples presented levels of Ag, Be, Cd, Pb, Se, Tl, and U below the limit of quantification, while for Ba, Co, and Ni around half of the samples were below this limit. The waterborne metal levels were not significantly different between the exorheic lakes. Waterborne metal levels in the freshwater lakes from Harmony Point did not show any clear relationship with their levels in the soil of the region or with bird guano, and overall, their levels indicate an environment without anthropogenic influence. Apparently, the Na levels are influenced by salt spray from the ocean, as they are related to the distance of the lakes from the ocean.
{"title":"Waterborne metal levels in four freshwater lakes from Harmony Point, Nelson Island, Antarctica.","authors":"Bernardo Baldisserotto, Vinícius M Neves, Valderi L Dressler, Cristiano N Rosa, Ulisses F Bremer, Waterloo Pereira Filho","doi":"10.1590/0001-3765202420231140","DOIUrl":"https://doi.org/10.1590/0001-3765202420231140","url":null,"abstract":"<p><p>The aim of this study is to analyze the waterborne metal levels in four lakes (one endorheic and three exorheic) of Harmony Point, Nelson Island, Antarctica. Water samples were analyzed by using a quadrupole type inductively coupled plasma mass spectrometer and an inductively coupled plasma optical emission spectrometer. The levels of As, Cu, Mn, Mo, and V were significantly lower and those of Cr, Mg, Na, and Sr were significantly higher in the endorheic lake than in the other lakes. Most water samples presented levels of Ag, Be, Cd, Pb, Se, Tl, and U below the limit of quantification, while for Ba, Co, and Ni around half of the samples were below this limit. The waterborne metal levels were not significantly different between the exorheic lakes. Waterborne metal levels in the freshwater lakes from Harmony Point did not show any clear relationship with their levels in the soil of the region or with bird guano, and overall, their levels indicate an environment without anthropogenic influence. Apparently, the Na levels are influenced by salt spray from the ocean, as they are related to the distance of the lakes from the ocean.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420230082
Rafaela Caroline S Pereira, Jussara S Dayrell, Ramiro Dário Melinski, Albertina P Lima
Amazonian white-sand ecosystems have predominantly sandy soils and a high amount of endemism, and several species found within them are adapted to long periods of drought. However, little is known about the variation in the structure of anuran assemblages in these ecosystems. Considering that most species are not uniformly distributed in heterogeneous landscapes, we tested the hypothesis that anuran assemblage variation in white-sand ecosystems is related to changes in vegetation structure. Specifically, we focused on a heterogeneous patch of white-sand ecosystems of the central Amazon and evaluated whether vegetation structure and soil characteristics, including root depth, influence the richness, abundance, and composition of anuran assemblages. Our results showed that low amounts of clay in the soil play an important role in structuring vegetation in these ecosystems, and these are the main factors that organize anuran assemblages. The Campinaranas close to the water bodies have a high species richness, while Campina landscapes limit the occupation of most of species. Our findings indicate that anurans undergo environmental filtering in white-sand ecosystems and are organized into hierarchical subgroups, in which only species with specialized reproduction can successfully occupy the most water-restricted environments.
{"title":"Determinants of anuran assemblages in Amazonian White-sand Ecosystems.","authors":"Rafaela Caroline S Pereira, Jussara S Dayrell, Ramiro Dário Melinski, Albertina P Lima","doi":"10.1590/0001-3765202420230082","DOIUrl":"https://doi.org/10.1590/0001-3765202420230082","url":null,"abstract":"<p><p>Amazonian white-sand ecosystems have predominantly sandy soils and a high amount of endemism, and several species found within them are adapted to long periods of drought. However, little is known about the variation in the structure of anuran assemblages in these ecosystems. Considering that most species are not uniformly distributed in heterogeneous landscapes, we tested the hypothesis that anuran assemblage variation in white-sand ecosystems is related to changes in vegetation structure. Specifically, we focused on a heterogeneous patch of white-sand ecosystems of the central Amazon and evaluated whether vegetation structure and soil characteristics, including root depth, influence the richness, abundance, and composition of anuran assemblages. Our results showed that low amounts of clay in the soil play an important role in structuring vegetation in these ecosystems, and these are the main factors that organize anuran assemblages. The Campinaranas close to the water bodies have a high species richness, while Campina landscapes limit the occupation of most of species. Our findings indicate that anurans undergo environmental filtering in white-sand ecosystems and are organized into hierarchical subgroups, in which only species with specialized reproduction can successfully occupy the most water-restricted environments.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420240255
Eskálath Morganna S Ferreira, Gabriela Garmendia, Vívian N Gonçalves, Juliana F M DA Silva, Peter Convey, Luiz Henrique Rosa, Silvana Vero, Raphael S Pimenta
The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of the Antarctic yeast strain Debaryomyces hansenii UFT8244 against the post-harvest phytopathogenic fungi Botrytis cinerea and Rhizopus stolonifer for the protection and preservation of strawberry fruit. The strongest inhibition of germination of B. cinerea (57%) was observed at 0 °C, followed by 40% at 25 °C. In addition, germ tubes and hyphae of B. cinerea were strongly surrounded and colonized by D. hansenii. Production of the enzymes β-1,3-glucanase, chitinase and protease by D. hansenii was detected in the presence of phytopathogenic fungus cell walls. The activity of β-1,3-glucanase was highest on day 12 of incubation and remained high until day 15. Chitinase and protease activities reached their highest levels on the day 15 of incubation. D. hansenii additionally demonstrated the ability to resist oxidative stress. Our data demonstrated that the main biocontrol mechanisms displayed by D. hansenii were the control of phytopathogenic fungal spore germination, production of antifungal enzymes and resistance to oxidative stress. We conclude that isolate D. hansenii UFT8422 should be further investigated for use at commercial scales at low temperatures.
在处理和预防采后水果变质的过程中,酵母的使用已被探索为杀真菌剂的有效替代品。在这里,我们评估了南极酵母菌株 Debaryomyces hansenii UFT8244 对采后植物病原真菌 Botrytis cinerea 和 Rhizopus stolonifer 的生物防治能力,以保护和保存草莓果实。0 °C 时对 B. cinerea 的发芽抑制最强(57%),其次是 25 °C 时的 40%。此外,B. cinerea 的芽管和菌丝被 D. hansenii 强烈包围和定殖。在植物病原真菌细胞壁存在的情况下,检测到 D. hansenii 产生了β-1,3-葡聚糖酶、几丁质酶和蛋白酶。在培养的第 12 天,β-1,3-葡聚糖酶的活性最高,并一直保持到第 15 天。几丁质酶和蛋白酶的活性在培养的第 15 天达到最高水平。此外,D. hansenii 还具有抗氧化能力。我们的数据表明,D. hansenii 的主要生物防治机制是控制植物病原真菌孢子萌发、产生抗真菌酶和抵抗氧化应激。我们的结论是,应进一步研究分离物 D. hansenii UFT8422 在低温条件下的商业应用。
{"title":"Biocontrol mechanisms of the Antarctic yeast Debaryomyces hansenii UFT8244 against post-harvest phytopathogenic fungi of strawberries.","authors":"Eskálath Morganna S Ferreira, Gabriela Garmendia, Vívian N Gonçalves, Juliana F M DA Silva, Peter Convey, Luiz Henrique Rosa, Silvana Vero, Raphael S Pimenta","doi":"10.1590/0001-3765202420240255","DOIUrl":"https://doi.org/10.1590/0001-3765202420240255","url":null,"abstract":"<p><p>The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of the Antarctic yeast strain Debaryomyces hansenii UFT8244 against the post-harvest phytopathogenic fungi Botrytis cinerea and Rhizopus stolonifer for the protection and preservation of strawberry fruit. The strongest inhibition of germination of B. cinerea (57%) was observed at 0 °C, followed by 40% at 25 °C. In addition, germ tubes and hyphae of B. cinerea were strongly surrounded and colonized by D. hansenii. Production of the enzymes β-1,3-glucanase, chitinase and protease by D. hansenii was detected in the presence of phytopathogenic fungus cell walls. The activity of β-1,3-glucanase was highest on day 12 of incubation and remained high until day 15. Chitinase and protease activities reached their highest levels on the day 15 of incubation. D. hansenii additionally demonstrated the ability to resist oxidative stress. Our data demonstrated that the main biocontrol mechanisms displayed by D. hansenii were the control of phytopathogenic fungal spore germination, production of antifungal enzymes and resistance to oxidative stress. We conclude that isolate D. hansenii UFT8422 should be further investigated for use at commercial scales at low temperatures.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1590/0001-3765202420221048e
[This corrects the article doi: 10.1590/0001-3765202420221048].
[此处更正文章 doi:10.1590/0001-3765202420221048]。
{"title":"Errata.","authors":"","doi":"10.1590/0001-3765202420221048e","DOIUrl":"https://doi.org/10.1590/0001-3765202420221048e","url":null,"abstract":"<p><p>[This corrects the article doi: 10.1590/0001-3765202420221048].</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420230462
Kívia L Ferrazzo, Cristiane C Danesi, Nara Maria B Martins, Raquel P Antoniazzi
This observational study aimed retrospectively assess the impact of the COVID-19 pandemic on the head and neck squamous cell carcinoma (HNSCC) diagnosis and severity of the disease in southern Brazil. All new cases diagnosed with HNSCC from March 11, 2019 to March 10, 2020 (pre-COVID-19) and from March 11, 2020 to March 10, 2021 (COVID-19) were included. The data collected were: date of the histopathological diagnosis, sociodemographic data, place of residence, data related to the tumor (location of the primary tumor, lymph node involvement, distant metastasis and TNM clinical staging), time elapsed between the diagnosis and treatment initiation. There was no significant difference in the number of new diagnoses in the COVID-19 group (n=45) compared to the pre-COVID-19 group (n=47). There was also no statistical difference regarding patients' sociodemographic profile, time between diagnosis and treatment, and overall TNM staging. However, the clinical N classification was more severe in the COVID-19 group (p=0.021). Patients diagnosed during the COVID-19 pandemic were 4.05 times more likely to have the N-stage more advanced (95% CI:1.62 - 10.12). Although there was no reduction in the number of new diagnosis of HNSCC during COVID-19 pandemic, the diagnosed cases showed lymph node metastasis in more advanced stages.
{"title":"Impact of the COVID-19 pandemic on the severity of newly diagnosed cases of head and neck cancer in southern Brazil.","authors":"Kívia L Ferrazzo, Cristiane C Danesi, Nara Maria B Martins, Raquel P Antoniazzi","doi":"10.1590/0001-3765202420230462","DOIUrl":"https://doi.org/10.1590/0001-3765202420230462","url":null,"abstract":"<p><p>This observational study aimed retrospectively assess the impact of the COVID-19 pandemic on the head and neck squamous cell carcinoma (HNSCC) diagnosis and severity of the disease in southern Brazil. All new cases diagnosed with HNSCC from March 11, 2019 to March 10, 2020 (pre-COVID-19) and from March 11, 2020 to March 10, 2021 (COVID-19) were included. The data collected were: date of the histopathological diagnosis, sociodemographic data, place of residence, data related to the tumor (location of the primary tumor, lymph node involvement, distant metastasis and TNM clinical staging), time elapsed between the diagnosis and treatment initiation. There was no significant difference in the number of new diagnoses in the COVID-19 group (n=45) compared to the pre-COVID-19 group (n=47). There was also no statistical difference regarding patients' sociodemographic profile, time between diagnosis and treatment, and overall TNM staging. However, the clinical N classification was more severe in the COVID-19 group (p=0.021). Patients diagnosed during the COVID-19 pandemic were 4.05 times more likely to have the N-stage more advanced (95% CI:1.62 - 10.12). Although there was no reduction in the number of new diagnosis of HNSCC during COVID-19 pandemic, the diagnosed cases showed lymph node metastasis in more advanced stages.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420240156
Matheus P DE Freitas, Ana Júlia F Souza, Julliane Yoneda, Diego P Sangi
2-(1,3-Benzoxazol-2(3H)-ylidene)-3-oxo-3-phenylpropanenitrile (1) and methyl-2-(1,3-benzoxazol-2(3H)-ylidene)(cyano)acetate (2) are observed as single isomers by NMR spectroscopy. A theoretical study was carried out to investigate if this is due to the exclusive presence of the most stable diastereoisomer or if the ene moiety undergoes fast rotation, thereby allowing for the observation of an average conformer. Indeed, the pronounced stabilization of the E stereoisomer, attributed to intramolecular hydrogen bonding, makes it the single obtained product.
{"title":"A theoretical view on the stereochemistry of 1,3-benzoxazol-2-(3H)-ylidenes obtained from double vinylic substitution.","authors":"Matheus P DE Freitas, Ana Júlia F Souza, Julliane Yoneda, Diego P Sangi","doi":"10.1590/0001-3765202420240156","DOIUrl":"https://doi.org/10.1590/0001-3765202420240156","url":null,"abstract":"<p><p>2-(1,3-Benzoxazol-2(3H)-ylidene)-3-oxo-3-phenylpropanenitrile (1) and methyl-2-(1,3-benzoxazol-2(3H)-ylidene)(cyano)acetate (2) are observed as single isomers by NMR spectroscopy. A theoretical study was carried out to investigate if this is due to the exclusive presence of the most stable diastereoisomer or if the ene moiety undergoes fast rotation, thereby allowing for the observation of an average conformer. Indeed, the pronounced stabilization of the E stereoisomer, attributed to intramolecular hydrogen bonding, makes it the single obtained product.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420231153
André L S Patriota, Filipe B M Barros, Arnaldo M P Carneiro, Pedro L Guzzo
Portland cement (PC) production is among the industrial activities that most emit harmful gases. Its replacement to green binders turns into a timely issue to face the global restrictions due to climate changes. In this study, some properties of cementitious pastes prepared with waste packing glass powder (GP) and silica fume (SF) were characterized in line with a prefixed alkaline equivalent limit. These materials were obtained in Northeastern Brazil. Grinding operations used to produce GP into four size ranges ([45-75] µm, < 45 µm; [25-45] µm, < 25 µm) were disclosed. X ray diffraction showed that GP and SF substitutions did not change the hydration products commonly observed in PC pastes. The portlandite content measured with thermogravimetry was affected by GP size in both unitary and binary substitutions. The compressive strength measured after 56 days of curing was dependent on portlandite and void index contents measured in hardened pastes. Scanning electron microscopy coupled to energy dispersive spectroscopy were useful to show the effect of the particle size on the pozzolanic activity. It was found that 5% of PC replacement for GP < 25 µm was enough to raise the compressive strength by ~5%. For binary substitution, the strength increasing was ~ 20 %. The collectors of solid residues are the main players of waste glass recycling in Brazil. It is expected that the results of this study contribute to take out these workers from the fringes of the citizenship.
硅酸盐水泥(PC)生产是排放有害气体最多的工业活动之一。面对气候变化带来的全球限制,用绿色粘合剂替代硅酸盐水泥已成为一个及时的问题。在这项研究中,根据预设的碱性当量限,对使用废弃包装玻璃粉(GP)和硅灰(SF)制备的胶凝浆料的一些特性进行了分析。这些材料取自巴西东北部。研究揭示了将 GP 制成四种粒度范围([45-75] µm、小于 45 µm;[25-45] µm、小于 25 µm)的研磨过程。X 射线衍射显示,GP 和 SF 的替代物不会改变 PC 浆料中常见的水化产物。用热重法测定的波长石含量受 GP 尺寸在单一和二元取代中的影响。固化 56 天后测得的抗压强度取决于硬化浆料中测得的硅灰石含量和空隙指数。扫描电子显微镜和能量色散光谱有助于显示颗粒大小对水泥酚醛活性的影响。研究发现,当 GP 小于 25 µm 时,5% 的 PC 替代足以将抗压强度提高 ~5%。对于二元替代,强度提高约 20%。固体残渣收集者是巴西废玻璃回收的主要参与者。预计这项研究的结果将有助于把这些工人从公民身份的边缘中解放出来。
{"title":"An investigation on the physical properties of cementitious pastes modified with low dosage of waste glass powder and silica fume.","authors":"André L S Patriota, Filipe B M Barros, Arnaldo M P Carneiro, Pedro L Guzzo","doi":"10.1590/0001-3765202420231153","DOIUrl":"https://doi.org/10.1590/0001-3765202420231153","url":null,"abstract":"<p><p>Portland cement (PC) production is among the industrial activities that most emit harmful gases. Its replacement to green binders turns into a timely issue to face the global restrictions due to climate changes. In this study, some properties of cementitious pastes prepared with waste packing glass powder (GP) and silica fume (SF) were characterized in line with a prefixed alkaline equivalent limit. These materials were obtained in Northeastern Brazil. Grinding operations used to produce GP into four size ranges ([45-75] µm, < 45 µm; [25-45] µm, < 25 µm) were disclosed. X ray diffraction showed that GP and SF substitutions did not change the hydration products commonly observed in PC pastes. The portlandite content measured with thermogravimetry was affected by GP size in both unitary and binary substitutions. The compressive strength measured after 56 days of curing was dependent on portlandite and void index contents measured in hardened pastes. Scanning electron microscopy coupled to energy dispersive spectroscopy were useful to show the effect of the particle size on the pozzolanic activity. It was found that 5% of PC replacement for GP < 25 µm was enough to raise the compressive strength by ~5%. For binary substitution, the strength increasing was ~ 20 %. The collectors of solid residues are the main players of waste glass recycling in Brazil. It is expected that the results of this study contribute to take out these workers from the fringes of the citizenship.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23eCollection Date: 2024-01-01DOI: 10.1590/0001-3765202420221041
Paula L G Oliveira, Eraldo A T Matricardi, Eder P Miguel, Ben Hur Marimon Júnior, Alba Valéria Rezende
Cerrado is the second largest biome in Brazil, and it is responsible for providing us several ecosystem services, including the functions of storing Carbon and biodiversity conservation. In this study, we developed a modeling approach to predict the Aboveground biomass (AGB) in Cerrado vegetation using Artificial Neural Networks (ANNs), vegetation indices retrieved from RapidEye satellite imagery, and field data acquired within the Federal District territory, Brazil. Correlation testing was performed to identify potential vegetation index candidates to be used as input in the AGB modeling. Several ANNs were trained to predict the AGB in the study area using vegetation indices and field data. The optimum ANN was selected according to criteria of mean error of the estimate, correlation coefficient, and graphical analysis. The best performing ANN showed a predictive power of 90% and RMSE less than 17%. The validation tests showed no significant difference between the observed and ANN-predicted values. We estimated an average AGB of 16.55± 8.6 Mg.ha-1 in shrublands in the study area. Our study results indicate that vegetation indices and ANNs combined could accurately estimate the AGB in the Cerrado vegetation in the study area, showing to be a promising methodological approach to be broadly applied throughout the Cerrado biome.
{"title":"Artificial Neural Network and Remote Sensing combined to predict the Aboveground Biomass in the Cerrado biome.","authors":"Paula L G Oliveira, Eraldo A T Matricardi, Eder P Miguel, Ben Hur Marimon Júnior, Alba Valéria Rezende","doi":"10.1590/0001-3765202420221041","DOIUrl":"https://doi.org/10.1590/0001-3765202420221041","url":null,"abstract":"<p><p>Cerrado is the second largest biome in Brazil, and it is responsible for providing us several ecosystem services, including the functions of storing Carbon and biodiversity conservation. In this study, we developed a modeling approach to predict the Aboveground biomass (AGB) in Cerrado vegetation using Artificial Neural Networks (ANNs), vegetation indices retrieved from RapidEye satellite imagery, and field data acquired within the Federal District territory, Brazil. Correlation testing was performed to identify potential vegetation index candidates to be used as input in the AGB modeling. Several ANNs were trained to predict the AGB in the study area using vegetation indices and field data. The optimum ANN was selected according to criteria of mean error of the estimate, correlation coefficient, and graphical analysis. The best performing ANN showed a predictive power of 90% and RMSE less than 17%. The validation tests showed no significant difference between the observed and ANN-predicted values. We estimated an average AGB of 16.55± 8.6 Mg.ha-1 in shrublands in the study area. Our study results indicate that vegetation indices and ANNs combined could accurately estimate the AGB in the Cerrado vegetation in the study area, showing to be a promising methodological approach to be broadly applied throughout the Cerrado biome.</p>","PeriodicalId":7776,"journal":{"name":"Anais da Academia Brasileira de Ciencias","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}