Brazilian Journal of Science

(250 Artigos indexados)

Aspectos qualitativos da carne bovina - (2023)

Solange Silva de Amorim, Thiara Jacira Vicuña Mendes Oliveira de Paula Machado, Aureliano José Vieira Pires, Amanda Santos Ribeiro, Priscila Coelho Silva Galvão

Volume: 2 - Issue: 9

Resumo. O agronegócio brasileiro, mesmo com a crise que afetou o mundo todo em função à pandêmica provocada pelo Covid-19, permaneceu em ascensão, em especial a pecuária de corte, pois manteve números crescentes na produção, exportação e renda no setor. A qualidade da carne vem se destacando e aprimorando o setor, pois é um fator que tem preocupado o consumidor, que procura um alimento seguro e com os requerimentos nutricionais adequados. Fatores como genética, alimentação, manejo e cuidados com a carcaça após o abate refletem diretamente na valorização e qualidade. É indispensável assegurar o bem estar durante a vida do animal para alcançar uma carcaça saudável e com procedência confiável. Os atributos sensoriais e visuais como a cor, suculência, sabor, maciez, textura, marmoreio e pH qualificam a carne. A cor é característica de maior influência no momento da compra e varia de acordo com a idade do animal e tipo de alimentação. A gordura atua como isolante térmico, interferindo e intensificando o sabor e a maciez da carne. Quanto mais elevado o grau de marmoreio maior a suculência, palatabilidade e maciez na carcaça. Além disso, têm-se fatores como manejo, escolha das raças e abate influenciam o rendimento e qualidade da carcaça bovina. Portanto, esta revisão de literatura visa identificar os aspectos gerais que interferem na qualidade de carne bovina, associados na escolha do consumidor, bem como os fatores extrínsecos e intrínsecos.

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Clinical safety of bovine intra-ovarian application of allogeneic mesenchymal stem cells - (2023)

Maurício Antônio Silva Peixer, Patricia Furtado Malard, Hilana dos Santos Sena Brunel, Joao Henrique Moreira Viana, Thuany Alencar-Silva, Juliana Lott de Carvalho, Robert Pogue

Volume: 2 - Issue: 9

Resumo. A basic premise of reproductive physiology is that females have a finite and non-renewable stock of germinative cells, which results in a decrease in reproductive capacity over time. For female bovines, a further factor associated with this decrease is follicular puncture (ovum pickup - OPU), a technique widely used for production of embryos in vitro. As such, it is necessary to seek therapeutic or preventive options for fertility problems, and one potential option is treatment with mesenchymal stem cells (MSC), which exercise a paracrine effect in combating inflammatory and degenerative processes. However, as important as evaluating the efficacy of such treatments is an evaluation of safety. In this context, the current study was carried out with the application of 2.5 x 106 allogenic MSC derived from adipose tissue, to the ovarian cortex of healthy nelore (n = 5) and girolando (n = 5) cows. The animals were subsequently evaluated by ultrasonography, clinical examination, number of viable oocytes collected, and rate of embryo production. None of the animals presented any clinical alteration or any alteration on ultrasonography after receiving the MSC. Furthermore, comparison between the number of viable oocytes, embryos produced, and rate of embryo production before and after MSC application did not show a difference. Based on these data, it can be concluded that intraovarian application of 2.5 x 106 adipose-derived MSC is safe, and this technique represents a potential for study as a therapy in cases of ovarian degeneration or lesions.

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Determinação do grau de sulfonação do SPEEK por titulação - (2023)

Marcela Carrera de Castro, Jorge Trota Filho

Volume: 2 - Issue: 9

Resumo. Polímeros termoplásticos aromáticos como o poli (éter-éter cetona) PEEK têm se mostrado muito promissores para a produção de membranas trocadoras de prótons (PEM), devido as suas propriedades. Estudos demonstram que polímeros modificados quimicamente podem apresentar características originais melhoradas. O processo de funcionalização por sulfonação é uma das estratégias de modificação de materiais poliméricos, que promove maior hidrofilicidade, melhor condutividade iônica, maior molhabilidade e melhor desempenho como PEM. O PEEK foi tratado com ácido sulfúrico, obtendo-se o SPEEK. O polímero foi titulado a fim de estudar seu grau de sulfonação (SD), avaliar sua relação com a capacidade de troca iônica (IEC) e sua potencial aplicação como PEM. Amostras de 0,3 g SPEEK foram imersas em solução de cloreto de sódio para a realização da troca protônica. Foram realizadas as titulações das soluções salinas com hidróxido de sódio e, através do volume obtido, foram obtidos sua IEC = 0,5435 meq.g-1 e seu SD = 0,61. Comprovou-se que a relação entre a massa de polímero, grau de sulfonação e capacidade de troca iônica pode ser modificada, em razão da otimização da quantidade disponível de polímero e que, tendo o conhecimento do SD do polímero é possível estimar a quantidade de base a ser consumida, que está relacionada quantidade de prótons oriundos do SPEEK e presentes na solução salina.

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Greek consumers attitudes and motivations against PDO/PGI Agrifoods - (2023)

Z. Likudis, M-F. Dafni

Volume: 2 - Issue: 9

Resumo. The study was set out to investigate the factors affecting consumers’ purchasing attitudes and their intention to buy PDO/PGI food products. A total of 615 consumers took part in the study from the municipality of Attica, Greece. The majority of the respondents consider PDO/PGI products of better quality and higher safety than the conventional ones, and they are also able to identify them. However, respondents are unsure whether these products are superior in terms of health benefits, less expensive and tastier than the conventional ones. Furthermore, consumers, who pay attention to the origin, the health claims, the label of a product, and have a high level of consumer awareness, are more likely to buy PDOs/ PGIs. Understanding the main factors that influence consumers to purchase PDO/PGI products, is a vital step towards the promotion of special labeled agri-foodstuffs, which could contribute to the local sustainable development.

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Haemato-biochemical indices and intestinal microbial population of broiler chickens fed diet supplemented with Prosopis africana (African mesquite) essential oil - (2023)

John Olujimi Alagbe, Oluchi C. Precious Agubosi, Rufus Adebisi Oluwafemi, Taiwo Oladoye Akande, Adegoke Emmanuel Adegbite, I. A. Emiola

Volume: 2 - Issue: 9

Resumo. The objective of this present study was to investigate the haemato-biochemical indices and intestinal microbial population of broiler chickens fed diets supplemented with Prosopis africana (African mesquite) essential oil (PAEO). A total of 540 one-day old broiler chicks of Ross 302 strain were allotted to six treatments with 6 replicates consisting of 15 birds each in a completely randomized design. Feed and water were given ad libitum, and all necessary management practices were strictly observed throughout the experiment, which lasted for 8 weeks. The birds in treatment 1 (T1) was fed a basal diet with no PAEO, T2 was fed basal diet plus 1.2 g kg-1 Oxytetracycline, T3, T4, T5 and T6 were fed basal diet plus PAEO at 200 mg, 400 mg, 600 mg and 800 mg kg-1 respectively. All haematological parameters and intestinal microbial population were influenced by the dietary treatments (p ˂ 0.05). Total protein, triglycerides, cholesterol and urea were significantly different (p < 0.05) across the dietary treatments and are within the physiological ranges reported for healthy chicken. However, serum tryglycerides, low density lipoprotein, high density lipoprotein, magnesium and chloride ion values were not affected by PAEO (p ˃ 0.05). It was concluded PAEO possess several properties – antioxidant, antimicrobial, hepatoprotective, immune-stimulatory, anti-inflammatory and physiological amongst others all of which are vital for the health enhancing effects in birds. Prosopis africana essential oil can be supplemented up to 800 mg kg-1 in the diets of broiler chickens without causing any deleterious effect on their blood profile.

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Histopathology of broiler chickens fed diets supplemented with Prosopis africana (African mesquite) essential oil - (2023)

John Olujimi Alagbe, Oluchi C. P. Agubosi, Rufus Adebisi Oluwafemi

Volume: 2 - Issue: 9

Resumo. This study was carried out to investigate the hepatic histopathology of broiler chickens fed diets supplemented with Prosopis africana (African mesquite) essential oil (PRSO). 300, 1-day old broiler chicks were randomly distributed into six treatments with 5 replicates consisting of 10 birds each. Birds in diet 1 (D1) was fed basal diet supplemented with 0 % PRSO, D2: basal diet with 1.0 g/kg-1 oxytetracycline, D3, D4, D5 and D6 were fed basal diet supplemented with PRSO at 200 mg, 400 mg, 600 mg and 800 mg/kg-1 respectively. The experiment lasted for 56 days and a completely randomized design was adopted. Phyto-constituents of PRSO revealed the presence of tannins (201.21 mg/g-1), flavonoids (677.83 mg/g-1), alkaloids (405.90 mg/g-1), saponins (75.62 mg/g-1), phenols (508.28 mg/g-1), phytates (20.10 mg/g-1) and oxalates (5.26 mg/g-1). Hepatic histopathology showed that tissues from D1, D3, D4, D5 and D6 showed no signs of any damage; the central vein, blood portal vessels showed no congestion. Mild hepatocellular damage was recorded among liver of birds in D2. It can be concluded that Prosopis africana essential oil are among the key alternative solutions to antibiotics because they contain bioactive compounds that are safe, effective and performs multiple biological functions in the body of animals.

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O uso da sequência didática no ensino de Física: A inserção dos estudantes da Escola Estadual Tabelião Júlio Maria, Touros-RN - (2023)

José Jefferson da Silva, Geneci Cavalcanti Moura de Medeiros

Volume: 2 - Issue: 9

Resumo. O referido texto trata-se das potencialidades das atividades laboratoriais para o ensino de física e das principais características para o ambiente educacional, promovendo uma aprendizagem diferenciada para estudantes do ensino médio, contemplando assim conteúdos de hidrostática. O referido artigo possui como objetivo geral sugerir e aplicar uma unidade didática para estudantes da primeira série do ensino médio da Escola Estadual Tabelião Júlio Maria, localizada no município de Touros, Rio Grande do Norte. São Propostas nesta Unidade didática cinco atividades laboratoriais utilizando-se materiais de fácil acesso, desta forma almeja-se verificar qual a contribuição que esta abordagem proporciona no processo de ensino aprendizagem no conteúdo de hidrostática, promover o trabalho em equipe e o espirito crítico com relação ao papel da física, além de identificar as potencialidades das atividades laboratoriais para os conteúdos previstos. Pensando na temática que envolve o estudo da hidrostática, a unidade didática é constituída de cinco atividades sendo elas: Ensinando o conceito de flutuação dos corpos na água, verificando o conceito de densidade e pressão através das atividades laboratoriais, A vela que levanta água e a garrafa chuveirinho. Nesse sentido, a física em consonância com as atividades laboratoriais com materiais de fácil acesso deixa de ser meramente abstrata e ganha requisitos práticos, pois o estudante está em contato real com os conceitos trabalhados na disciplina, sendo assim relacionado com o dia a dia dos estudantes imersos nas atividades propositivas. Ao termino do trabalho de pesquisa, espera-se que esse material possa servir além da aplicação do conhecimento para os estudantes, o estimulo para professores estudantes de física, já que as atividades aqui propostas objetivam trabalhar alguns conceitos abstratos, sendo primordial para o contexto da formação de professores, formalizando principalmente o desenvolvimento do saber de todos os envolvidos nesse contexto educacional.

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Prognosis of exploration on Chat GPT with artificial intelligence ethics - (2023)

N. Gowri Vidhya, D. Devi, Nithya A., T. Manju

Volume: 2 - Issue: 9

Resumo. Natural language processing innovations in the past few decades have made it feasible to synthesis and comprehend coherent text in a variety of ways, turning theoretical techniques into practical implementations. Both report summarizing software and sectors like content writers have been significantly impacted by the extensive Language-model. A huge language model, however, could show evidence of social prejudice, giving moral as well as environmental hazards from negligence, according to observations. Therefore, it is necessary to develop comprehensive guidelines for responsible LLM (Large Language Models). Despite the fact that numerous empirical investigations show that sophisticated large language models has very few ethical difficulties, there isn't a thorough investigation and consumers study of the legality of present large language model use. We use a qualitative study method on OpenAI's ChatGPT3 to solution-focus the real-world ethical risks in current large language models in order to further guide ongoing efforts on responsibly constructing ethical large language models. We carefully review ChatGPT3 from the four perspectives of bias and robustness. According to our stated opinions, we objectively benchmark ChatGPT3 on a number of sample datasets. In this work, it was found that a substantial fraction of principled problems are not solved by the current benchmarks; therefore new case examples were provided to support this. Additionally discussed were the importance of the findings regarding ChatGPT3's AI ethics, potential problems in the future, and helpful design considerations for big language models. This study may provide some guidance for future investigations into and mitigation of the ethical risks offered by technology in large Language Models applications.

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Self-efficacy, motivation and academic performance of students during the flexible learning mode - (2023)

Maria Crisella A. Dela Cruz, Angelina Lumanlan, Helen Grace Felix, Isabel Dizon, Arnello Valerio, Evelyn Dayrit, Sherry Jean Sison, Rommel Gaña, Elaine Joy Gatchalian

Volume: 2 - Issue: 9

Resumo. Self-Efficacy is the belief that a person is capable of achieving a specific goal or performing a particular task while motivation represents the foundation for success in all activities that an individual engages in. This study aimed to determine the correlations between self-efficacy, motivation and academic performance of 862 students. Using spearman’s rho, results revealed that self-efficacy and motivation go along together for all students with different specializations. Most of the students’ grades are not directly affected by the motivation and self-efficacy. Responses of students for most of the challenges they encountered during the flexible learning mode are limited home setup for activities that require actual performances followed by the distraction they get from social media. Results of this study reveals that even during the pandemic, the students have positive outlook in life, but grades are not dependent on their self-efficacy and motivations.

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The official EFL textbook in cameroonian technical schools and the needs of dressmaking students: an evaluation of interactions in English lère - (2023)

Edwige Damaris Hagbe

Volume: 2 - Issue: 9

Resumo. The present paper examines the contents of the Premiere textbook of EFL in order to find out if it fits the needs and interests of the students of the technical fields such as bespoke tailoring and dressmaking. Over the years, the indifference of technical students towards English has been a topical issue and still raises debates nowadays. The aim of this paper is to show that the existence of a single book for all Premiere classes can account for the lack of interest in English generally observed in technical schools. Emphasis is laid on the analysis of themes, the reading passages and the selection of pictures in Interactions in English Ière. In other words, this research attempts to show that the official textbook of English for francophone technical education is not tailored to the needs and interests of the learners. The research methodology consisted in reading and analysing the selected corpus in a bid to find out if its content pleases the intended audience made up of dressmaking students. The EFL students and teachers were also interviewed in order to probe their attitudes towards the selected English book. The paper ends with suggestions on how to improve on the English book for that specific set of students. The aim is to raise more awareness in the educational circle, create more motivation in the target learners and ameliorate their performances in English.

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Anti-microbial activity of seed oils & protein estimation of seed-content in Clitoria ternetea, Lagenaria siciraria & Ziziphus mauritiana - (2023)

Porshia Sharma, Pragya Rathore, Yogesh Choudhary, Yash Tatwade, Akshada Joshi

Volume: 2 - Issue: 8

Resumo. Asian plants of flower, vegetable and fruit named Clitoria ternetea, Lagenaria siciraria and Ziziphus mauritiana respectively are known for their extensive uses in traditional medicine as well as traditional treatment of various diseases and infections. Several studies have already been done so far on these plants and its various parts but the studies on their seeds as well as their seed oilwas lacking. In this work, we determined the protein content of these seeds as well as we extracted the seed oils and determined their anti-microbial activity independently along with the anti-microbial activity by mixing all these oils together in equal ratios. Both, protein determination and anti-microbial activity determination showed considerable and potential results. The Lagenaria siciraria seeds (in ethanol extract) showed highest protein content amongst all i.e., 4.44 (μg/mL-1) whereas Clitoria ternetea seeds displayed highest protein content (in water extract) amongst all i.e., 5.07 (μg/mL-1). The anti-microbial activity of the mixed seed oil showed better and great results as compared to individual anti-microbial activity of seed oils.

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Bioactive compounds of Prosopis africana oil (african mesquite) using gas chromatography and mass spectrometry (GC-MS) technique - (2023)

John Olujimi Alagbe

Volume: 2 - Issue: 8

Resumo. Phytochemicals (bioactive compounds) are generally regarded as chemicals of plant origin used for plants for growth, defense against competitors and pathogens. They also have a wide range of pharmacological activities including – antiarrhythmic, antioxidant, antimalarial, vasodilatory, antimicrobial, analgesics, hepato-protective, anti-inflammatory, hypo-cholesterolemic, anti-androgenic, antiviral, antifungal and immune-modulatory. This study was carried out to investigate the bioactive compounds of Prosopis africana oil (african mesquite) using gas chromatography – mass spectrometry technique. A total of 73 bioactive compounds 77.16% were identified based on their peak areas. The major compounds identified in the oil sample were; prosogerin A 29.90%, caryophyllene 12.33%, 2,4-bis (1-phenylethyl) phenol 5.80%, gallic acid 5.22%, β-cyclocitral 3.11%, β-sitosterol 2.50%, α-terpinene 2.09% and ellagic acid 2.04%. The other compounds were less than 1%, however, they exert various pharmacological properties. It was concluded that Prosopis africana oil is loaded with phytochemicals and also has several health promoting properties and it can also be used as a remedy for the treatment of several ailments in human being and animals.

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Conocimiento sobre medidas preventivas de infecciones de transmisión sexual en adolescentes - (2023)

Leydy Dayely Caisaluisa Quimbita, Jose Luis Herrera Lopez

Volume: 2 - Issue: 8

Resumo. La presente investigación fue desarrollada con el objetivo de “determinar el conocimiento sobre medidas preventivas de infecciones de transmisión sexual en adolescentes, tomando como referencia la población de la Unidad Educativa Catorce de Julio-Juan Abel Echeverría” para lo cual se siguió el enfoque cuantitativo de diseño transversal. La muestra censal quedó conformada por un total de 200 adolescentes de la Unidad Educativa Catorce de Julio-Juan Abel Echeverría, quienes respondieron una encuesta para recolectar información sobre el conocimientos de ITS, datos que permitieron determinar que: el 59% era del sexo femenino; el 55% ya habían tenido relaciones sexuales, de los cuales el 47% tuvieron relación sexual entre los 15 y 19 años; el 82% indica que en su primera relación coital puede quedar embarazada; el 57% usa preservativos como método seguro para prevenir ETS; el 75% usa método de barrera; el 18% considera que no puede quedar embaraza en la primera relación con coito por lo que no se protegen; el 8% no usa métodos anticonceptivos; el 89% considera que el método abstinencia es no tener relaciones sexuales. Se estableció que el 57% de los adolescentes de la UE poseen un nivel alto de conocimientos sobre medidas preventivas de infecciones de transmisión sexual, aunque su conocimiento es básico reconocen algunas enfermedades de trasmisión sexual.

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Desenvolvimento de um aplicativo para divulgação de editais nas áreas de inovação, ciência, tecnologia e empreendedorismo essencial na promoção do acesso seletivo de informação - (2023)

Fabiana Arcanja dos Santos

Volume: 2 - Issue: 8

Resumo. Anualmente dezenas de editais de fomento são publicados e disseminados na rede web através de seus próprios sites ou em sites de pesquisa e de marketing, que tem o perfil de disseminar informação nesse âmbito, fazem a obtenção de editais e os disponibilizam em bancos de dados. O desenvolvimento de mais ferramenta como aplicativos indicativo e de disseminação seletiva de editais nas áreas de captação em inovação, tecnologia e empreendedorismo para as principais agências de fomento governamentais prioritariamente (CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico, FINEP - Financiadora de Estudos e Projetos, e CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), empresas que tendem publicar editais periodicamente, como as de capital aberto (Petrobrás, Eletrobras), agências de fomentos baianas FAPESB - Fundação de Amparo à Pesquisa do Estado da Bahia, Coelba - Companhia de Eletricidade do Estado da Bahia, Chesf - Companhia Hidrelétrica do São Francisco e empresa privada Sebrae - Confederação Nacional das Indústrias, sem prejuízo de inserção de novas instituições quando possível, se faz pertinente para ampliar o fluxo de informações nesse contexto.

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Irradiação de alimentos: Revisão comparativa, histórica e difusão do processo - (2023)

Ricardo Ramos, Eutropio Vieira Batista

Volume: 2 - Issue: 8

Resumo. A utilização da irradiação em alimentos não é uma técnica nova, mas vem apresentando relevantes avanços em sua aceitação e nos benefícios que eles podem providenciar aos alimentos. Logo, este trabalho teve por objetivo avaliar a história da utilização da técnica de irradiação nos alimentos. Bem como, observar quais foram os principais benefícios e metodologias empregadas. Em seguida, constatou-se que esta é uma técnica segura e eficiente para aumentar o tempo de vida em prateleira dos alimentos e livrar de patógenos. Além disso, apresenta uma regulamentação de suma importância que garante qualidade e segurança para estes alimentos, difundindo ainda mais o processo no meio social e acadêmico.

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Manejo químico de plantas daninhas infestantes da cultura do trigo - (2023)

Leandro Galon, Barbara Casagrande de Oliveira, Maico André Michelon Bagnara, Moises Henrique Schmitz, Camila Viasdeski de Oliveira, Sabrina Camila Pigatto, David Fambre Mezadri, Siumar Pedro Tironi

Volume: 2 - Issue: 8

Resumo. As plantas daninhas competem com o trigo por água, luz e nutrientes, o que reduz a produtividade e, portanto, os lucros do triticultor. Sendo assim, o objetivo deste trabalho foi avaliar a seletividade e a eficácia de herbicidas aplicados em pré e pós-emergência para o manejo de plantas daninhas infestante do trigo. Dois experimentos foram instalados em blocos casualizados, com quatro repetições. Os herbicidas usados foram; em pré-emergência o imazethapyr + flumioxazin, pendimethalin e flumioxazin, e em pós-emergência o iodosulfuron, pyroxsulam, metsulfuron e clodinafop, e dois controles, um capinado e outro infestado. Os herbicidas com maior fitotoxicidade à cultivar de trigo TBIO Sinuelo foram a mistura de imazethapyr + flumioxazin e associado a essa o uso de iodosulfuron, pyroxsulam, metsulfuron e clodinafop. A aplicação de imazethapyr + flumioxazin + metsulfuron resultou em menor dano às variáveis fisiológicas do trigo. A aplicação em pré-emergência de imazethapyr+flumioxazin e em pós-emergência de iodosulfuron-methyl, pyroxsulam e metsulfuron ocasionaram o melhor controle de nabo. O melhor controle de azevém foi obtido com o uso de pendimenthalin e flumioxazin em associação com clodinafop. Os tratamentos imazethapyr + flumioxazin, imazethapyr + flumioxazin + iodosulfuron, pendimenthalin + iodosulfuron, flumioxazin + iodosulfuron, imazethapyr + flumioxazin + pyroxsulam, pendimenthalin + pyroxsulam, flumioxazin + pyroxsulam, imazethapyr + flumioxazin + clodinafop e flumioxazin + clodinafop foram os tratamentos mais eficientes no controle de aveia preta. O pendimenthalin + iodosulfuron apresentou as melhores respostas em ambos os experimentos, tanto em termos de seletividade quanto de eficácia, para os componentes de rendimento de grãos.

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Nilpotent and supersoluble groups - (2023)

Behnam Razzaghmaneshi

Volume: 2 - Issue: 8

Resumo. Let G = AB be the mutually permutable product of this supersoluble subgroups A and B. If G’ is nilpotent, then G is supersoluble.

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Óxido de CaO e hidróxido de (Ca(OH)2) no tratamento de volumosos - (2023)

Gabriel Rodrigues Silva Oliveira, Aureliano José Vieira Pires, Raiane Barbosa Mendes, Tainan da Silva Batista

Volume: 2 - Issue: 8

Resumo. Objetivou-se com esta revisão compilar informações a respeito do tratamento de alimentos volumosos com óxidos e hidróxidos de cálcio e seu fornecimento para ruminantes. Esse tratamento visa melhorar a digestibilidade dos volumosos por meio hidrólise alcalina, beneficiando o valor nutricional. Estudos vem sendo desenvolvidos com intuito de melhorar as características nutritivas e diminuir a frequência de corte pelo armazenamento da cana-de-açúcar a partir de seu tratamento com óxido (CaO) ou hidróxido de cálcio (Ca(OH)2). No entanto, esses tratamentos nem sempre conseguem melhorar as composições dos alimentos, principalmente nos teores de fibras e digestibilidade. Deste modo, o tratamento de forragens utilizando óxidos e hidróxidos de cálcio não é recomendado pela falta de resultados que demonstrem melhoria na qualidade da forragem, características de consumo e desempenho animal.  

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Síntese de semicondutores de diferentes composições e sua capacidade de absorção na região UV-A - (2023)

Luana Góes Soares da Silva, Annelise Kopp Alves

Volume: 2 - Issue: 8

Resumo. Fotocatalisadores são sólidos semicondutores que se caracterizam por converterem a energia contida em fótons (luz) em energia eletroquímica disponível em um sistema químico, tanto para oxidação, como para a redução de compostos ou espécies químicas (íons). Á aplicação do TiO2 em fotocatálise heterogênea, adquire relevância, devido à sua eficiência na decomposição de poluentes da água, do ar, bactérias, células cancerígenas e na degradação de compostos orgânicos tóxicos. Assim, este trabalho se propôs a sintetizar por electrospinning fibras de TiO2 e de TiO2 dopadas com H2WO4 ou Na2WO4.2H2O. Estas amostras foram tratadas termicamente entre 650 ºC e 800 ºC. Caracterizadas quanto: a morfologia por microscopia eletrônica de varredura (MEV), fases cristalinas por difração de raios X (DRX), e fotoatividade mediante ensaios de degradação de 125 mL de uma solução 20 ppm do corante alaranjado de metila. Os resultados apontam a amostra de TiO2/Na2WO4.2H2O (800 ºC) mais efetiva na degradação do corante, possivelmente devido a existência de uma sincronicidade entre as propriedades químicas e físicas dos óxidos de titânio e tungstênio e a formação das vacâncias de O2.

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Use of the 555 integrated circuit for the construction of a PWM module - (2023)

Tiago Destéffani Admiral

Volume: 2 - Issue: 8

Resumo. The use of technology has become increasingly viable in classrooms, especially in physics classes. Explaining phenomena related to circuits becomes simpler when we can provide practical examples to students. The present article aims to describe the construction of a low-cost PWM module, which was used in the classroom to demonstrate the basic principles of digital electronics. The module was built with the 555 integrated circuit and a few other components. The assembly was made on a breadboard. The results from the operation of the board were analyzed with a digital oscilloscope and corresponded to what was expected in theory, the compatibility of the pulse width could be successfully verified, as well as the effect of simulating the analog output signal. Alternatively, the prototype was also used with an electric motor to visualize the influence of pulse width on the motor's rotation.

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Assessment of integrated soil nutrient sources on growth and yield parameters on sorghum in the soil of Makurdi, Nigeria - (2023)

T. S. Ter, B. C. Anjembe, J. T. Maga

Volume: 2 - Issue: 7

Resumo. Research was carried out at University Commercial Crop Farm, Federal University of Agriculture Makurdi, to evaluate the effects of different soil nutrient sources on the growth and yield of sorghum in the 2016 and 2017 cropping season under rain-fed condition. The experiment consisted of fourteen treatments; (I) Control, (II) Soybean intercrop, (III) 2.0 t/ha-1 of PM, (IV) 2.0 t/ha-1 of PM + Soybean, (V) 3.5 t/ha-1 of PM, (VI) 3.5 t/ha-1 of PM + Soybean, (VII) 0.2 t/ha-1 of CP, (VIII) 0.2 t/ha-1 of CP + Soybean, (IX) 0.4 t/ha-1 of CP, (X) 0.4 t/ha-1 of CP + Soybean, (XI) 30 kg N/ha-1, (XII) 30 kg N/ha-1 + Soybean, (XIII) 60 kg N/ha-1, and (XIV) 60 kg N/ha-1 + Soybean. The experiment was laid in Randomised Complete Block Design in three (3) replications. Sole applications of compost manure at 0.4 t/ha-1 had significant difference on leaf area. Soybean as nutrient source did not have significant difference on crop parameters. Poultry manure, NPK fertilizer and compost manure significantly affected growth and yield parameters in the two cropping seasons. The highest yield were obtained from application of NPK fertilizer at 60 kg N/ha-1 in plots where sorghum was intercropped with soybeans, this was not however significant when compared with plots where NPK fertilizer was applied without soybean mixture.

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Avaliação anatômica do fruto de jambo amarelo (Syzygium jambos (L.) Alston) e análise físico-química farinácea da casca e polpa e semente - (2023)

Matheus Chavaglia Cavalet, Antonio Carlos Pereira de Menezes Filho, Carlos Frederico de Souza Castro, Matheus Vinicius Abadia Ventura

Volume: 2 - Issue: 7

Resumo. Syzygium jambos é uma espécie frutífera introduzida no Brasil, apresentando frutos com aroma agradável e gosto adocicado. O trabalho teve por objetivo a avaliação anatômica do fruto e a análise físico-química das farinhas obtidas da casca e polpa e da semente. A anatomia do fruto utilizado foi à descritiva, as farinhas foram produzidas utilizando casca e polpa (FCP) e sementes (FS), as análises físico-químicas foram: teores de umidade, cinzas e lipídios, °Brix, pH, proteína, carboidratos por diferença, vitaminas, A, C e E, índice de oxidação (min/s), DPPH (%), compostos fenólicos, pectina, β-Caroteno, licopeno, flavonoides, antocianinas, cor (L*, a* e b*), C* e h°, e FT-IR. Foram obtidos valores importantes sobre os teores de umidade, cinzas, lipídios, °Brix, pH, proteínas e carboidratos. O conteúdo de vitamina A = 1,50 e 5,37 µg RAE, vitamina C = 1,76 e 3,52 mg 100 g-1, e vitamina E = 0,066; 0,064 m/m, atividade antioxidante para FCP = 48,19%, fenólicos totais de 8,16 e 11,88 mg EAG 100 g-1, pectina = 8,37 e 3,40%, β-caroteno = 18,01 e 64,47 µg 100 mL-1, flavonoides = 0,90 e 1,61 mg 100 g-1, antocianinas = 0,06; 0,41 mg 100 g-1 para as farinhas de FCP e FS respectivamente. As farinhas de jambo amarelo apresentaram potenciais resultados podendo ser empregadas na fabricação de produtos farináceos para a indústria de alimentos.

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Culture media influence on vegetative growth and mycelia weight of Mycosphaerella fijiensis: implication for inoculum production - (2023)

Alfred Kumakech, Tonny Opio

Volume: 2 - Issue: 7

Resumo. Six (6) culture media (Potato Dextrose Agar, Malt Extract Agar, AFPA Base, Czapek Dox Agar, Nutrient Agar and Yeast Extract), were tested for their effect on colony growth and mycelia weight of Mycosphaerella fijiensis. The isolate of M. fijiensis (Kaw10) produced vegetative mycelial growth on all six-culture media. Culture media effect on the level of vegetative mycelial colonization and mycelia weight was significant. The highest and lowest vegetative mycelia colonization was recorded on malt extract (23.5 mm) and AFPA Base (4.2 mm), respectively. Similarly, culture media effect on mycelia weight was significant. Malt extract agar produced more mycelia weight (0.34g) than the control, PDA (0.11g). Collectively, our data identify malt extract agar as a good medium for improving growth of Mycosphaerella fijiensis. 

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Effects of Utazi leaf (Gongronema latifolium) and Aloe vera (Aloe barbadensis) on the quality attribute of formulated herbal yoghurt - (2023)

Ifeoma Elizabeth Mbaeyi-Nwaoha, Alhassan Freedom Ojochegbe, Chidera Juliet Nnamani

Volume: 2 - Issue: 7

Resumo. The effect of utazi leave and aloe vera on the quality attribute of formulated herbal yoghurt was studied. Utazi leaf was processed into extract sorting, washing, mashing, sieving, and packaging while aloe vera was processed into paste cleaning, washing, blending, sieving, packaging and refrigeration. Herbal yoghurt was produced from mixture of utazi extract/aloe vera and plain yoghurt at different ratios (WFMA = 297 mL plain yoghurt and 3 mL utazi extract; YC = 300 mL plain yoghurt only; YU1 = 297 mL plain yoghurt + 3 mL utazi extract; YU2 = 294 mL plain yoghurt + 6 mL utazi extract; YAV1 = 297 mL plain yoghurt + 3 mL aloe vera paste; YAV2 = 294 mL plain yoghurt + 6 mL aloe vera paste. The herbal yoghurts samples were subjected to proximate, micronutrients, microbial, phytochemical, sensory properties analysis using standard methods. The proximate composition results of the herbal yoghurt showed that the crude protein varied from 4.75 to 5.75%, fat 3.35 to 4.52%, ash 1.55 to 2.01%, fiber 0.09 to 0.97%, moisture 78.1 to 82.73% and carbohydrate 6.99 to 10.20%. Calcium, Magnesium, vitamin A and E contents ranged from 13.95 to 14.52, 0.90 to 2.50, 1.99 to 3.55 and 5.00 to 6.00 mg/100 g-1, respectively. Microbial results showed that the mould count for the control (YC) had higher total viable count 15x107 (CFU/mL-1) and higher mould count 15x107 (CFU/mL-1) compared to the composite herbal yoghurt. The phytochemical analyses of the herbal yoghurt values showed tannin to range between 0.12 and 0.51%, alkaloids 1.05 to 4.10 % and saponin ranged from 2.05 to 5.05. The sensory results of the herbal yoghurt showed that taste ranged from 6.15 to 7.35, consistency 6.35 to 6.95, appearance 6.70 to 7.45, mouthfeel 6.20 to 720, aroma 6.30 to 7.30, aftertaste 5.00 to 7.15 and over all acceptability ranged from 6.20 to 8.00.

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Estimate of chickpea production (Cicer arietinum L.) as a function of plant phenology - (2023)

Isabel Duarte

Volume: 2 - Issue: 7

Resumo. Chickpea is a crop of the indeterminate type which can be an advantage to estimate in advance the production of this crop. The lack of water, cold or heat are the most limiting factors for the success of this culture; in the emergency phase, situations of waterlogging or extreme drought lead to an irregular installation of the culture, on the other hand, drought, excess water and extreme heat during the reproductive period, cause floral abortion and/or shorter cycles, and consequently, smaller income. Chickpea yield essentially depends on the number of seeds per unit area, which in turn depends on the length of the reproductive period. This is a problematic situation that proves the complexity of estimating the yield in leguminous crops in relation to species of determined habit. We try to know the dates of development of chickpeas, namely when the vegetative apex becomes reproductive (Beginning of Flowering, BF) and when the last flower of the apex no longer develops (End of Flowering, EF), this knowledge is fundamental anticipate and estimate the productive potential. Portugal is a country with a typical Mediterranean climate that has high capacity to produce grain legumes and the chickpea breeding program started at Plant Breeding Station, Elvas, Portugal in 1986. Since this data we have determined the dates of the BF and EF and, due to the difference between the two, the Reproductive Period (RP); the longer this period, the greater the number of pods and seeds per plant, and, as a consequence, greater final productions. In this way, over the course of 24 years, we have been recording the dates of entry into flowering and the end of flowering according to the thermal sum in Growing Degree Days (GDD) of by genotype, by trial and by year. In this analysis it was found that the BF is achieved when the sum of the GDD reaches 757 ºC, for maximum temperatures of 23 ºC, and the EF for sums of 1224 ºC and maximum temperatures of 30 ºC, that is, when temperatures above 28 ºC are registered, for two or three days in a row, is an indicator that the EF is approaching. It may happen later if precipitation occurs when the temperature reaches those values, but it varies from genotype to genotype. The new varieties, Elipse, Electra, Eleia, Eladir and Elfo confirm this situation, with the ELEIA variety standing out earlier in flowering.

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