Utilization of carbon nanotubes in hydrogen electrosynthesis from tropical fruit fermentation

The use of fossil fuels, especially oil and gas, has accelerated in recent years, resulting in the global energy crisis. The fermentative biological process is a sustainable way to produce hydrogen, as it can use as a substrate various types of carbohydrate-rich industrial and household waste such as fruit, minimizing but not completely eliminating the problems caused by improper disposal of this material. From a perspective of energy conservation and use of renewable sources for energy generation, this work aims to contribute to the identification of the use of a currently unused portion of energy, optimizing hydrogen production from a fuel cell. microbial. The main nanomaterial used in electrolysis was carbon nanotubes (CNT) incorporated into carbon felt (CF). Cyclic voltammetry studies were also performed on three electrode systems: vitreous carbon electrode as working electrode, platinum electrode as auxiliary electrode and Ag / AgCl / Cl- as reference electrode. An electrochemical cell formed by two separate compartments was constructed. Before starting the electrolysis experiment, an experimental design was performed using the complete factorial design technique to analyze the influence of the variables selected for this study. The independent variables selected were: Tropical fruit liquor concentration in %v/v, type of working electrode, electrolysis time and pH of the electrolyte medium. The observed variable was the concentration in% v / v of the hydrogen gas obtained in the electrolysis. After the results of the tests, it was concluded that carbon nanotubes can be used as working electrode, presenting success in the hydrogen production process and that the pH of the electrolytic medium has a strong influence on this process. The present work was concluded presenting an alternative way in the production of a renewable energy source. Keywords: Electrolysis, Tropical Fruits, Hydrogen

Barras de Whey Protein: estudo prospectivo

Whey protein bars become a potential attraction for consumers that have several properties that bring health benefits. It aimed to carry out a survey on the scientific and technological production of whey protein in scientific articles and patents in the database. The article platforms (Scopus, Science direct and Scielo) and patents: Espacenet, INPI and Lens used in the searches for keywords: “protein bars”, “whey protein” and “whey protein bars”, making it possible to collect data from publications/year (2012–2022). The United States has almost 30% of all publications related to protein bars, and in 2nd place is China with almost 15%. In Brazil, the number of publications has grown in recent years, with growth in new technologies and new products in 2017. This shows a great opportunity to carry out research and development in this area, more specifically in additives for the food industry.Barras de whey protein tornam-se um potencial atrativo para os consumidores por apresentar várias propriedades que trazem benefícios à saúde. Neste artigo, o objetivo é realizar um levantamento sobre a produção científica e tecnológica de whey protein em artigos científicos e patentes no banco de dados. As plataformas de artigos (Scopus, Science Direct e Scielo) e de patentes Espacenet, INPI e Lens foram utilizadas nas buscas para palavras-chave: “protein bars”, “whey protein” e “whey protein bars”, possibilitando coletar dados de publicações/ano (2012-2022). Os Estados Unidos possuem quase 30% de todas as publicações relacionadas a barras de proteína, e em segundo lugar está a China com quase 15%. Já no Brasil, a quantidade de publicações tem crescido nos últimos anos, apresentando em 2017 crescimento em novas tecnologias e novos produtos. Isso mostra uma grande oportunidade para realização de pesquisa e desenvolvimento nessa área, mais especificamente em aditivos para a indústria de alimentos

Prospecção Tecnológica sobre Sensores e Biossensores Eletroquímicos para fins Ambientais

Electrochemical sensors/biosensors are versatile devices that have great interest to various industries, such as quality control and environment ones. Since they are straightforward and cheap, those devices provide less time consumption and economy. The present research presents a survey on scientific and technological production through data from articles and patents related to the theme. The article platforms (Scopus, Science direct, Web of Science and Scielo) and patent plataforms Espacenet and WIPO were used in the searches for the keywords “electrochemical sensor/biosensor” and “electrochemical environmental sensor/biosensor”, being possible to collect data from publications/year (2012-2022), correlated countries and the areas of publications or international patent classification (IPC). China and the US were the most active countries in publishing articles and filing patents, with China being the predominant one. Thus, the growing number of publications shows the need to develop technologies and innovations for this topic.Sensores/biossensores eletroquímicos são dispositivos versáteis e de grande interesse para várias indústrias, como a de controle de qualidade e ambiental. Por serem práticos e baratos, eles proporcionam maior agilidade e economia. A presente pesquisa apresenta um levantamento sobre a produção científica e tecnológica por meio de dados de artigos e patentes relacionados ao tema. As plataformas de artigos (Scopus, Science Direct, Web of Science e Scielo) e de patentes: Espacenet e WIPO foram utilizadas nas buscas para as palavras-chave: “sensor/biosensor electrochemical” e “sensor/biosensor electrochemical environmental”, sendo possível coletar dados de publicações/ano (2012-2022), países correlacionados e áreas de publicações ou Classificação Internacional de Patentes (CIP). A China e os EUA foram os países mais atuantes nas publicações de artigos e depósito de patentes, sendo a China o predominante. Assim, o crescente número de publicações mostra a necessidade de desenvolvimento de tecnologias e inovações para o referido tema

Electrochemical Study of Carbon Nanotubes/Nanohybrids for Determination of Metal Species Cu2+ and Pb2+ in Water Samples

The use of nanomaterials, such as nanoparticles and nanotubes, for electrochemical detection of metal species has been investigated as a way of modifying electrodes by electrochemical stripping analysis. The present study develops a new methodology based on a comparative study of nanoparticles and nanotubes with differential pulse anodic stripping voltammetry (DPASV) and examines the simultaneous determination of copper and lead. The glassy carbon electrode modified by gold nanoparticles demonstrated increased sensitivity and decreased detection limits, among other improvements in analytical performance data. Under optimized conditions (deposition potential −0.8 V versus Ag/AgCl; deposition time, 300 s; resting time, 10 s; pulse amplitude, 50 mV; and voltage step height, 4 mV), the detection limits were 0.2279 and 0.3321 ppb, respectively, for determination of Pb2+ and Cu2+. The effects of cations and anions on the simultaneous determination of metal ions do not exhibit significant interference, thereby demonstrating the selectivity of the electrode for simultaneous determination of Pb2+ and Cu2+. The same method was also used to determine Cu2+ in water samples

Diferentes estratégias para a reticulação de quitosana

One of the most important aspects of chitosan' derivatization depends on the crosslinking of their polymeric chains. This chemical strategy may confer new properties to those derivatives, which can be used to enhance their biotechnological applications. So far, this work aims to discuss some strategies related to the crosslinking of chitosan focusing on reagents, reaction mechanisms and properties/applications of the crosslinked derivatives in several fields of science

Dispositivo Sensor, Processo De Preparação Do Dispositivo, Método Para Detecção De Artemisinina Em Amostras Multicomponentes, E Uso

DISPOSITIVO SENSOR, PROCESSO DE PREPARAÇÃO DO DISPOSITIVO MÉTODO PARA DETECÇÃO DE ARTEMISININA EM AMOSTRAS MULTICOMPONENTES, E USO. A presente invenção tem como objeto proporcionar um dispositivo amperométrico para detecção de artemisinina e o processo de produção do mesmo. O dispositivo é de fácil operação, susceptivel a miniaturização e portabilidade. Esse sensor proporciona diagnosticar alterações dos níveis de artemisinína, in foco de forma mais precisa, rápida, simples e seletiva de que os sistemas atualmente existentes. Em especial, o dispositivo compreende uma base de pasta de carbono, a partir da imobilização de hemina em sílica gel modificada com óxido de titánio, capaz de quantificar níveis baixos de artemisinina (ARN) em uma amostra em especial uma amostra multicomponente como, por exemplo, um isolado, um extrato vegetal, uma fração enriquecida, uma composição fitoterápica, uma composição cosmética e uma composição farmacológica. A presente invenção se situa nos campos da química e farmácia.BRPI0900203 (A2)G01N27/327G01N27/406BR2009PI00203G01N27/327G01N27/40

Electrochemical behavior of metribuzin on a glassy carbon electrode in an aqueous medium including quantitative studies by anodic stripping voltammetry

The electrochemical behavior of the herbicide metribuzin was studied in an aqueous solution on glassy carbon, carbon paste/Nujol oil and carbon paste/castor oil using cyclic voltammetry, square-wave voltammetry, differential pulse voltammetry, controlled-potential coulometry and electrolysis, for quantification and decontamination purposes. The main electrolytic products obtained from the reduction of metribuzin, after consumption of 8.26 mol electron mol-1, were deaminometribuzin and diketometribuzin. The anodic wave observed after electroreduction is associated with the oxidation of the methylthiolate generated in the electrolytic process. This wave was used to quantitatively determine metribuzin in a commercial sample by anodic stripping voltammetry. The electro-Fenton method was employed to promote decontamination by eliminating the herbicide, resulting in 80% of mineralization of the metribuzin

Determination of genotoxic effect of trifluralin on Colossoma macropomum (Teleostei: Characidae: Serrasalminae, Cuvier, 1816) using a multibiomarker approach

The herbicide trifluralin is one of the most widely herbicides used in weed control. This study aims to evaluate the genotoxic potential of the trifluralin herbicide on the Colossoma macropomum (tambaqui) using a multi-biomarker approach. The C. macropomum is highly adapted and predominant species in a variety of water bodies in the delta region of the São Francisco River and other river systems in Brazil. The mutagenic and the genotoxic effects of different trifluralin concentrations (0.25, 0.5, 0.75, 1.0 mg L-1) in peripheral erythrocytes of C. macropomum were investigated using micronucleus (MN), comet assay and apoptosis test. After an exposure period of 96 h, the results showed a significant rate of micronuclei and nuclear abnormalities in erythrocytes of C. macropomum exposed to 0.5, 0.75, 1.0 mg L-1 of trifluralin. Compared to controls, the genetic damage index (GDI) showed significant variations (**p < 0.01 and ***p < 0.001) for all the trifluralin concentrations tested. The genotoxicity of trifluralin herbicide on C. macropomum was confirmed by the micronucleus test and comet assay