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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Aplicacao do metodo de analise por ativacao a determinacao de elementos tracos em amostras do pulmao

ROGERO, SIZUE O. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:36:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:11Z (GMT). No. of bitstreams: 1 04377.pdf: 5279166 bytes, checksum: fa75c13e4628ec66b28b9571552d8f92 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
322

Guiding Preservice Teachers to Critically Reflect: Towards a Renewed Sense about English Learners

January 2011 (has links)
abstract: The purpose of this practitioner inquiry was to explore the use of Guided Critical Reflection (GCR) in preparing preservice teachers for English learners (ELs). As a teacher researcher, I documented, analyzed, and discussed the ways in which students in my course used the process of GCR to transform their passively held understandings about ELs. Specifically, the research questions were: 1) What are preservice teachers' common sense about teaching and learning related to ELs? 2) How does GCR transform preservice teachers' common sense about ELs? 3) What is my role as an educator in creating opportunities for GCR? I utilized methods for data collection that fit my teaching practices. Data sources included three types of observations (self-reflective field notes, audio recordings of each class, and notes documented by an outside observer), student-work artifacts, and my audio reflection journal. I analyzed data inductively and deductively using a modified analytic induction approach. Building on previous research concerning the use of reflection in teacher preparation, I define GCR as the process in which I guided preservice teachers to acknowledge and examine their common sense about ELs, reframe what they know in light of course learning, and transform their understandings. Five major findings emerged from this study. First, preservice teachers entered the course with common sense notions about ELs rooted in their educational and life experiences. Students felt comfortable sharing what they knew about ELs, but needed to be scaffolded to examine how their life experiences shaped their common sense. Within the course, preservice teachers framed and reframed their common sense in different ways. Through the process of GCR, students evidenced a renewed sense about ELs. Finally, my role as a teacher involved establishing a comfortable learning environment, valuing my students' common sense as the catalyst for course learning, and guiding students through their reflective work. Ultimately, I was able to create opportunities for GCR because I too was reflecting on my practices, just as I was asking my students to reflect on their common sense about ELs. / Dissertation/Thesis / Ph.D. Curriculum and Instruction 2011
323

Experimentos de eletrostática como metodologia de aprendizagem significativa / Experiments of electrostatics as a methodology of significant learning

Luiz, Rodrigo de Lima [UNESP] 01 October 2018 (has links)
Submitted by Rodrigo De Lima Luiz (rodrigodelimaluiz@hotmail.com) on 2018-11-21T19:51:52Z No. of bitstreams: 1 DISSERTAÇÃO DEFINITIVA.pdf: 3442563 bytes, checksum: a1ec4acfa5218338bbc6cc71e90ad441 (MD5) / Approved for entry into archive by Claudia Adriana Spindola null (claudia@fct.unesp.br) on 2018-11-22T10:50:34Z (GMT) No. of bitstreams: 1 luiz_rl_me_prud.pdf: 3385709 bytes, checksum: 3b7f3df96984f568b958099cfbebbdf2 (MD5) / Made available in DSpace on 2018-11-22T10:50:34Z (GMT). No. of bitstreams: 1 luiz_rl_me_prud.pdf: 3385709 bytes, checksum: 3b7f3df96984f568b958099cfbebbdf2 (MD5) Previous issue date: 2018-10-01 / Neste trabalho, foi pesquisada uma forma alternativa de aplicação de experimentos em sala de aula, na qual os alunos foram responsáveis pela confecção deles e não meros expectadores que observaram o professor realizar a atividade experimental. Assim, os estudantes produziram, executaram e tiraram suas conclusões acerca das atividades propostas. Propôs-se, neste trabalho, a aplicação de uma sequência didática para abordar eletrostática utilizando atividades experimentais, como metodologia de aprendizagem significativa, proposta por David Ausubel. Antes da realização dos experimentos, o tema foi contextualizado através de vídeos que mostravam situações intrigantes no cotidiano dos alunos, envolvendo eletrostática. Também foi abordada a história da eletricidade com suas principais descobertas e como os conceitos científicos foram evoluindo ao longo do tempo. Em seguida, utilizando materiais de baixo custo e fáceis de serem encontrados e seguindo roteiros experimentais, os alunos construíram experimentos que permitiram a verificação dos três processos de eletrização: atrito, contato e indução. Também, verificaram a distribuição de cargas em condutores em equilíbrio eletrostático, a blindagem eletrostática e o poder das pontas. O trabalho visou despertar o interesse e motivação dos alunos nas aulas de Física, desenvolvendo suas habilidades em seguir roteiros simples, coletar e analisar dados, além de aplicar os conceitos, abordados em sala, em situações de seu cotidiano. / In this work, an alternative way of applying experiments in the classroom has been investigated, in which the students were responsible by their confections and not mere spectators who observed the teacher to perform an experimental activity. Thus, students produced, performed, and concluded on the proposed activities. It was proposed, in this work, the application of a Didactic Sequence to approach electrostatic using experimental activities, as significant learning methodology, proposed by David Ausubel. Before the experiments, the theme was contextualized through videos that showed intriguing situations in the daily life of students, involving electrostatics. It was also discussed the electricity history with its main discoveries, and how scientific concepts were developed over time. Then, using inexpensive, easy-to-find materials and following experimental script, the students constructed experiments that allowed the verification of the three electrification processes: friction, contact and induction. Also, they verified the charges distribution in conductors in electrostatic equilibrium, the electrostatic shield and the power of the tips. The aim of this work was to arouse student’s interest and motivation in physics classes, developing their skills in following simple scripts, collecting and analyzing data, and applying the concepts, addressed in the classroom, in everyday situations.
324

Difference in Heat Generation Comparing “Grinding” and “Cutting” Single Crown Preparation Technique

Garis, David, Johansson, Christoffer January 2018 (has links)
The main purpose of this study was to examine the difference in intrapulpal temperature (IPT) comparing a “grinding” and a “cutting” technique during single crown preparation. The difference in preparation time between the two techniques was also examined. A thermocouple was placed in the pulp chamber of 20 extracted human permanent molar teeth. The teeth were placed in a silicone model. The model was immersed in a thermostatically controlled water bath with a temperature of 37 degrees centigrade (°C), and with a water level reaching the cementoenamel junction at the teeth. For both preparation techniques an electric handpiece (NSK Ti-Max Ti85L 1:5) was used. A diamond bur was used for the “grinding” and a carbide bur for the “cutting” technique. The IPT during preparation was measured with a K-thermocouple connected to Testo 176 T4 temperature data logger. There was a significant difference in IPT rise between the two techniques for preparing the teeth. The “cutting” technique showed a higher mean temperature, 31.9 °C, compared to the “grinding”, 29.5 °C (p<0.05). Neither reached the critical value of 5.5 °C IPT increase. The “grinding” technique averaged a longer preparation time of 106 seconds per tooth than the “cutting” technique (p<0.05). Our study shows that the “cutting” technique results in a higher mean temperature but that both preparation techniques can be considered as safe in regard to IPT during single crown preparation as long as sufficient water cooling is applied.
325

Using Cogenerative Dialogues to Open Conversations of Rigor in Teacher Preparation Programs

January 2012 (has links)
abstract: The purpose of this action research study was to examine the impact of cogenerative dialogues on instructor and student perceptions of rigor in a master's and certification program for alternatively certified teachers. Additionally, the study was designed to determine if these open dialogues would impact instructional decisions of college instructors in the program. The investigator used a mixed methods research model that included surveys, interviews, and video of the dialogues to measure the impact. The results of the study indicated that both sets of participants remained consistent in their identification and definition of the term rigor. The cogenerative dialogues did have an impact on instructor understanding of student definitions of rigor. Instructors began to change some instructional decisions as a result of the dialogues in small groups. / Dissertation/Thesis / Ed.D. Educational Leadership and Policy Studies 2012
326

Avaliação da resistência à fadiga de instrumentos rotatórios do Sistema Pro Taper Universal por meio de ensaio dinâmico /

Estrela, Cristiane Bonanato January 2008 (has links)
Orientador: Idomeo Bonetti Filho / Banca: Mario Tanomaru Filho / Banca: Fábio Luiz Camargo Villela Berbert / Banca: Giulio Gavini / Banca: Oscar Faciola Pessoa / Resumo: O objetivo deste estudo foi avaliar o efeito da velocidade de deslocamento na resistência à fratura por fadiga de instrumentos rotatórios de níquel-titânio por meio de ensaio dinâmico de flexão. Foram avaliados instrumentos S1, S2, F1, F2 e F3 pertencentes ao Sistema ProTaper Universal (Dentsply/Maillefer) sendo 20 de cada número num total de 100 instrumentos, que foram divididos em dois grupos. Todos os instrumentos foram submetidos a ensaio de flexão por meio de um dispositivo elaborado especificamente para este estudo. O aparato para teste foi composto por um canal artificial curvo, fabricado em aço inoxidável temperado e que apresentava 5mm de raio e ângulo de curvatura de 45º. Um motor elétrico X-Smart (Dentsply/Maillefer) com um contra-ângulo com redução de 16:1 foi regulado para trabalhar à uma velocidade constante de rotação de 300rpm e com um torque de 2 N.cm. A este contraângulo foram acoplados os instrumentos ProTaper Universal que foram introduzidos no canal artificial e ali giraram livremente até sua fratura. O aparato regulava a velocidade de deslocamento axial do canal artificial para frente e para trás, na direção dos instrumentos, simulando a entrada e saída dos instrumentos no canal radicular. Foram utilizadas duas velocidades de deslocamento do canal simulado, sendo que os instrumentos do Grupo I foram submetidos à uma velocidade mais lenta (146 deslocamentos por minuto) e no Grupo II a velocidade foi mais rápida (189/min). O tempo até a fratura foi registrado por um cronômetro e, a partir daí, encontrou-se o número de rotações para fratura. A comparação do número médio de ciclos até a fratura foi realizada por meio do teste t de Student para amostras independentes. Os resultados mostraram que ocorreu diferença estatisticamente significante do número médio de ciclos até a fratura apenas para o instrumento F3 (p=0,025)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the fracture strength under fatigue load of Nickel-Titanium rotatory endodontic instruments by means of a dynamic flexure strength test. The S1, S2, F1, F2 and F3 instruments from the ProTaper Universal System (Dentisply/Maillerfer) were evaluated. Twenty samples of each instrument, totalizing 100 samples, were divided in two groups. All instruments were submitted to the flexure strength test using a device specially developed for this study. The device was composed by a 45º sloped artificial root canal, made with tempered stainless steel, with radius of 5mm. An X-Smart (Dentisply/Maillefer) electric engine that had a contra-angle with rotatory reduction of 16:1 was stated to work with a constant speed of 300rpm and with a torque of 2N.cm. Each ProTaper Universal Instrument was individually attached to the contra-angle and then introduced into the artificial root canal where they rotate freely until failure. The test apparatus also has a potentiometer that was responsible to regulate the axial dislodgment speed of the artificial root canal forward and backward, against instruments direction, simulating the inward and the outward movement of the instruments into the real root canal. Two displacements speeds of the simulated root canal were used, so that the instruments in Group I were submitted to the slower speed (146 displacements per minute - d/min) and in Group 2 to the faster speed (189d/min). The time elapsed until failure of the instruments was chronometrically measured and registered; then, the number of rotations was calculated from this measurement. The comparison between the mean numbers of cycles until failure was done by the T-Student test. The results of this study showed statistically significant differences in the mean number of cycles until failure only for the F3 instrument (p=0.025). In Group I it was found about 201 fewer cycles... (Complete abstract click electronic access below) / Doutor
327

Information inför koloskopi : en litteraturstudie / Information on colonoscopy : a literature rewiew

Karström, Ingrid January 2018 (has links)
Colonoscopy is the gold standard and most common examination of the colon. Preparation is mandatory, but can be difficult for the patient. The aim of this study was exploring contributing factors rendering improved colonoscopy preparation. Method: An integrative review were using. 12 studies met the selection criteria. Articles were included from 2008 until 2017. The search terms used were before, care, colonoscopy, endoscopy, experience, information, nurse and preparation. The results: reported in two categories show that those patients who had personal contact with the nurses prior to the colonoscopy were most satisfied and best prepared for their examination. The feeling of sufficient information showed that the patient had less knowledge of the examination than desired. Conclusion: Information by a nurse prior to preparation helped patients to get better prepared for colonoscopy. Further, the patients were less worried and felt better prepared. This facilitated both the preparation and the colonoscopy. The result of the preparation was also proven better after verbal information by a nurse. Implication: In order to obtain well-informed and well-prepared patients, there seems to be much to gain by improving given information to enable the patients to feel safe and have a better preparation before colonoscopy. / Bakgrund: Koloskopi är gold standard och den vanligaste undersökningsmetoden av tjocktarmen och kan användas både för diagnostik och behandling. Undersökningen kräver vissa förberedelser som patienter ibland kan ha svårt att genomföra. Syftet var att utforska vad som bidrar till att patienterna kommer väl förberedda till sin koloskopiundersökning. Metod: En integrerad litteraturstudie resulterade i 12 artiklar från 2008 till 2017. Sökord som använts var before, care, colonoscopy, endoscopy, experience, information, nurse och preparation. Resultatet som redovisas i två kategorier visade att de patienter som hade haft personlig kontakt med sjuksköterskor, före undersökningen, var mest nöjda med informationen och bäst förberedda för koloskopiundersökningen. Känslan av tillräcklig information visade att man som patient hade mindre kunskap om undersökningen än vad man önskade. Konklusion: Resultatet av denna studie har visat att det som bidragit till att patienterna kommit väl förberedda till sin koloskopiundersökning har varit en personlig kontakt med information inför undersökningen. Patienterna kände sig bättre förberedda och blev mindre oroliga. Både undersökning och förberedelser upplevdes mindre besvärliga. Implikation: För att få välinformerade och väl förberedda patienter måste arbetet fortsätta med att undersöka vilken information som behövs för att patienterna ska känna sig trygga och väl förberedda inför sin undersökning.
328

The development of luminescent lanthanide complexes for biological applications

Dadabhoy, Anjum January 2001 (has links)
To serve well as luminescent labels in biological applications, complexes of the lanthanide ions need to fulfil many criteria, including the requirement of high quantum yields, stability towards dissociation in biological media and preferably, excitation at wavelengths over 350 nm. Herein, a number of aspects regarding the sensitization of europium(III) and terbium(III) ions are discussed with respect to the design and development of novel complexes. The effect of the addition of anions such as fluoride and phosphate to the Eu(III) and Tb(III) complexes of a known tris(bipyridyl) cryptate, are studied with a view to gaining a better understanding of non-radiative deactivation pathways of the lanthanide excited state. Enhancements of Eu3+ emission within the cryptate are noted whilst with the Tb3+ analogue, emission is significantly reduced upon displacement of OH by these ions. A new ligand based on a polyaminocarboxylate structure with a single bipyridyl chromophore is then reported, which displays nine-coordination around the enclosed lanthanide ion. The luminescence properties of the europium complex are very good but the terbium complex shows more complex behaviour, suggestive of a back energy transfer mechanism from the terbium excited state to the ligand triplet level. The development of ligands with mixed N,O pyrido-phenol chromophoric groups, which are expected to be better sensitizers of terbium(III) luminescence, is also outlined. Finally, in the quest to sensitize europium using longer wavelengths, acridone is incorporated into an azamacrocyclic structure and luminescence is observed from the complexed Eu3+. The quantum yield of luminescence is found to increase with decreasing distance between the sensitizer and the ion, and in the presence of coordinating donor atoms.
329

Efeito do lantânio nas propriedades de catalisadores de ferro para a produção de estireno

Santos, Manuela de Santana 29 October 2007 (has links)
Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2016-09-15T15:53:18Z No. of bitstreams: 1 Dissertação completa Manuela.pdf: 2230006 bytes, checksum: c333e5f619891c4c93f788ac275e016a (MD5) / Approved for entry into archive by Vanessa Reis (vanessa.jamile@ufba.br) on 2016-09-15T16:03:28Z (GMT) No. of bitstreams: 1 Dissertação completa Manuela.pdf: 2230006 bytes, checksum: c333e5f619891c4c93f788ac275e016a (MD5) / Made available in DSpace on 2016-09-15T16:03:28Z (GMT). No. of bitstreams: 1 Dissertação completa Manuela.pdf: 2230006 bytes, checksum: c333e5f619891c4c93f788ac275e016a (MD5) / CAPES / Entre os intermediários utilizados na indústria petroquímica, o estireno é um dos mais importantes. Este monômero é empregado na produção de diferentes materiais poliméricos, sendo o poliestireno o mais importante. Desde 1930, a desidrogenação catalítica do etilbenzeno em presença de vapor d’água é mais importante via de produção de estireno. O catalisador clássico, baseado em óxido de ferro contendo potássio e cromo, entretanto, rapidamente desativa com o tempo, causando a necessidade de troca do catalisador a cada um ou dois anos. Como conseqüência, vários estudos estão sendo conduzidos com o intuito de descobrir dopantes alternativos que possam tornar o catalisador mais estável. Com esse objetivo, investigou-se neste trabalho, o efeito do lantânio e do método de preparação sobre as propriedades catalíticas da hematita. Amostras com diferentes razões molares ferro/lantânio (5, 10, 15 e 20) foram preparadas através do método sol-gel a partir de nitrato de lantânio, nitrato de ferro e hidróxido de amônio. Os catalisadores foram caracterizados por difração de raios X, medida de área superficial específica e redução à temperatura programada e avaliados na desidrogenação do etilbenzeno em presença de vapor d’água. Foi observado que as amostras mais ricas em lantânio (Fe/La = 5 e 10) se mostraram amorfas aos raios X, mas as outras eram formadas por hematita. Após a reação, detectou-se magnetita, em todas as amostras, hematita e um óxido de ferro e lantânio (FeLaO3). O lantânio evitou a sinterização dos sólidos, mas apenas nos catalisadores novos. Os catalisadores dopados com lantânio se mostraram mais ativos do que a hematita pura e este efeito aumentou com a quantidade de lantânio até o valor de Fe/La = 10; quantidades maiores desse dopante diminuiu a atividade. Esta melhoria do catalisador foi atribuída ao papel do lantânio em elevar a atividade intrínseca, assim como em estabilizar as espécies Fe+3, consideradas como a fase ativa. A fim de promover uma melhoria ainda maior desse catalisador, o efeito do tipo do agente precipitante foi também investigado, através da preparação de amostras com carbonato de sódio e potássio e hidróxido de sódio e potássio. Os catalisadores foram caracterizados pelas mesmas técnicas e também por espectroscopia fotoeletrônica de raios X e espectroscopia Mössbauer. O emprego de carbonato de sódio e potássio e hidróxido de sódio e potássio favoreceu a cristalização e a produção de sólidos com baixos valores de área superficial específica; a resistência contra redução aumentou. Também foi observado que sódio e potássio atuaram como promotores estruturais, sendo o potássio o mais eficiente, especialmente quando associado a espécies hidroxilas. O catalisador preparado com carbonato de potássio foi o mais ativo, um fato que foi atribuído à produção de ferrita de potássio na superfície das partículas, responsáveis pelo aumento da atividade dos sítios. O mais eficiente método de preparação desse sólido é a adição dos reagentes sobre a água; através da adição de carbonato de potássio aos nitratos de ferro e lantânio ou vice-versa foram obtidos catalisadores menos ativos. O catalisador foi mais ativo com conversão de 13% quando comparado a uma amostra comercial, que apresentou conversão de 9,0%, então é promissor para aplicação industrial / Among the intermediates used in petrochemical industry, styrene is by far one of the most important. This monomer is used for the production of different polymeric materials, the most important being polystyrene. Since 1930, the catalytic dehydrogenation of ethylbenzene in the presence of steam is the most important route for styrene production. The classical catalyst, based on iron oxide containing potassium and chromium, however, fastly deactivates with time, causing the need of replacing the catalyst each one or two years. As a consequence, several studies have been carried out in recent years aiming to get alternative dopants which could make the catalysts more stable. With this goal in mind, the effect of lanthanum and of the preparation method on the catalytic properties of hematite was investigated in this work. Samples with different iron to lanthanum molar ratio (5, 10, 15 and 20) were prepared by sol-gel method from lanthanum nitrate, iron nitrate and ammonium hydroxide. The catalysts were characterized by X-ray diffraction, specific surface area measurements and temperature programmed reduction and evaluated in the dehydrogenation of ethylbenzene in the presence of steam. It was found that the samples richest in lanthanum (Fe/La = 5 and 10) were amorphous to X-ray but the other were made off hematite. After reaction, magnetite, hematite and an iron and lanthanum oxide (FeLaO3) were detected in all the samples. Lanthanum avoided sintering but only for the fresh catalysts. The lanthanum-doped catalysts were more active than pure hematite and this effect increased with lanthanum amount up to Fe/La = 10; higher amounts of this dopant decreased the activity. This improvement of the catalysts was assigned to the role of lanthanum in increasing the intrinsic activity as well as in stabilizing the Fe+3 species, wich are supposed to be the active phase. In order to improve this catalyst even more, the effect of the kind of the precipitant agent was also investigated, by preparing samples with sodium and potassium carbonate and sodium and potassium hydroxide. The catalysts were characterized by the same techniques and also by X-ray photoelectron spectroscopy and Mossabuer spectroscopy. The use of sodium and potassium carbonate and hydroxide makes the crystallization easier and favors the production of solids with low specific surface areas; the resistance against reduction increased. It was also found that sodium and potassium were structural promoters, being potassium the most effective one, especially when associated with hydroxide species. The catalyst prepared with potassium carbonate was the most active one and this was assigned to the production of potassium ferrite on the particle surface, responsible for the increase of active of the sites. The most efficient way to prepare this solid is by adding all reagents to water; by adding potassium carbonate to the iron and lanthanum nitrate or vice-versa less active catalysts were produced. The catalyst was more active (13% of conversion) when compared to the commercial sample which showed 9% of conversion and thus is promising for industrial applications.
330

Investigação de metais, metaloides, halogênios e isoflavonas em amostras de soja e derivados

Barbosa, José Tiago Pereira January 2011 (has links)
177f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-03T15:12:44Z No. of bitstreams: 1 Tese - José Tiago P. Barbosa - Versão Digital.pdf: 2697646 bytes, checksum: 8a6596b96acedc91d9eedf51d2ff97e2 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-23T15:43:21Z (GMT) No. of bitstreams: 1 Tese - José Tiago P. Barbosa - Versão Digital.pdf: 2697646 bytes, checksum: 8a6596b96acedc91d9eedf51d2ff97e2 (MD5) / Made available in DSpace on 2013-04-23T15:43:22Z (GMT). No. of bitstreams: 1 Tese - José Tiago P. Barbosa - Versão Digital.pdf: 2697646 bytes, checksum: 8a6596b96acedc91d9eedf51d2ff97e2 (MD5) Previous issue date: 2011 / CAPES / A soja é uma leguminosa que possui notável relevância no cenário internacional essencialmente em função de suas características funcionais e nutracêuticas. O consumo da soja é considerado benéfico não somente pela potencialidade nutricional associada, como também pelo efeito preventivo contra inúmeras doenças crônicas principalmente em virtude da presença de isoflavonas em sua constituição. O objetivo do trabalho consistiu no desenvolvimento de estratégias para a determinação da composição multielementar e do teor das isoflavonas daidzeína e genisteína em amostras de soja em grãos e derivados comercializadas/cultivadas nas cidades de Salvador e Barreiras, Bahia e Uberlândia, Minas Gerais. Para a avaliação multielementar foram propostos dois procedimentos: decomposição por via úmida assistida por radiação micro-ondas empregando ácidos diluídos (PAD) e decomposição utilizando combustão induzida por micro-ondas (MIC), empregando técnicas espectrométricas (ICP OES e ICP-MS) para detecção dos analitos. O procedimento de análise cromatográfica foi desenvolvido para a determinação de daidzeína e genisteína nas amostras estudadas empregando a técnica HPLC-DAD. Para o procedimento PAD foram avaliadas diferentes concentrações de HNO3 (2,1 – 14,5 mol L-1) utilizando H2O2 como agente oxidante auxiliar para a decomposição de aproximadamente 250 mg de amostra. A eficiência de decomposição para as diferentes concentrações ácidas foi avaliada considerando os parâmetros acidez e teor de carbono residual e percentual de recuperação dos analitos, de modo que a concentração de 2,1 mol L-1 em HNO3 foi selecionada. O procedimento de decomposição empregando MIC permitiu a decomposição de uma massa de amostra de 400 mg, utilizando como solução absorvedora HNO3 a 6,0 mol L-1 para a determinação multielementar. Para a determinação dos halogênios Cl, Br e I, foi utilizada como solução absorvedora NH4OH a 100 mmol L-1. A exatidão dos procedimentos PAD e MIC foi avaliada com material de referência certificado (NIST-1568a) e o desempenho quanto à precisão e LOQ foi também avaliado. Estes procedimentos se mostraram adequados para a determinação multielementar nas amostras sendo considerados alternativas promissoras, devido à minimização do consumo de reagentes e de geração de efluentes, de acordo com os princípios da química verde. Na determinação das isoflavonas, foi proposto um procedimento de análise cromatográfica empregando-se extração acelerada (ASE) com solvente (metanol) e posterior separação e detecção destes analitos por HPLC-DAD utilizando os solventes acetonitrila e ácido acético em eluição isocrática. Para a validação do método foram considerados os parâmetros: seletividade, linearidade, precisão, limites de detecção e quantificação. Os resultados obtidos estiveram nas faixas: daidzeína (10,3 a 34,0 μg g-1) e genisteína (18,5 a 77,8 μg g-1). Este procedimento se mostrou adequado para a identificação e quantificação destas isoflavonas nas amostras. O presente trabalho contribuiu para traçar um perfil preliminar das amostras de soja em grãos e derivados em termos de micronutrientes, contaminantes e as isoflavonas daidzeína e genisteína. / Salvador

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