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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.
21

A case study of Turkish teachers’ perceptions and practices regarding Communicative Language Teaching in English

Brodin, Martina January 2014 (has links)
The aim of this study was to gain an insight into how teachers work practically with the Communicative Oriented Curriculum in English and what factors that could influence the teachers’ methodology. The investigation partially replicated a study by Kırkgöz (2008). The study was conducted at three state elementary schools in Turkey by using multidimensional qualitative research procedures, including classroom observations and interviews. Results demonstrated that all participants showed attributes identified to an Eclectic-Oriented teaching approach placing them in the middle of a continuum from Transmission to Interpretation-Oriented teachers. The results were later compared with the original study displaying both a satisfying and unsatisfying outcome depending on a qualitative or quantitative comparison. Findings also indicated that a holistic perspective must be considered in order to interpret and understand the results.
22

Viabilidade t?rmica de um forno solar fabricado com sucatas de pneus

Varela, Pedro Henrique de Almeida 26 July 2013 (has links)
Made available in DSpace on 2014-12-17T14:58:22Z (GMT). No. of bitstreams: 1 PedroHAV_DISSERT.pdf: 2659101 bytes, checksum: 089bb4653a9ce23c256b8c7cfed002c8 (MD5) Previous issue date: 2013-07-26 / The proposed design provides a solar furnace alternative, box-like, low-cost operation to be used in cooking, comprising three scrap tires to make the recycling thereof. The tires were coupled to each other, forming an enclosure, which stood on its bottom covered by a parable multiple mirrors made from a urupema (sieve indigenous) and the inner sides of the oven aluminum sheet painted black, obtained from beer cans, thus being made to obtain the increase in the concentration of solar radiation incident on the inside of the prototype studied. Two tires were attached, leaving an air layer between them, with the function of thermal insulation. The third tire aimed to support the other two and thermally insulate the bottom of the oven. Externally was placed a metal frame with flat mirrors to reflect the incident rays into the oven, having a mobility to correct the apparent motion of the sun. Its primary feature is the viability of clean, renewable energy to society by tackling the ecological damage caused by the large-scale use of wood for cooking food. The tests show that the furnace reached the maximum temperature of 123.8 ?C and baking various foods such as pizza, bun, and other lasagne in an average time 50 minutes. Proves the feasibility of using the oven. Presenting still able to improve their performance with the addition of new materials, equipment and techniques / O projeto proposto apresenta um forno solar alternativo, tipo caixa, de baixo custo para ser utilizado na opera??o de coc??o, composto por tr?s sucatas de pneus, para fazer a reciclagem dos mesmos. Os pneus foram acoplados entre se, formando um recinto, onde se colocou em sua parte inferior uma par?bola coberta por m?ltiplos espelhos confeccionada a partir de uma urupema (peneira ind?gena) e nas laterais internas do forno chapas de alum?nio pintadas da cor preta, obtidas de latas de cerveja, sendo feito assim para a obten??o do aumento na concentra??o da radia??o solar incidente no interior do prot?tipo estudado. Dois pneus foram unidos, ficando uma camada de ar entre eles, com a fun??o de isolante t?rmico. O terceiro pneu teve a finalidade de suporte para os outros dois e isolar termicamente o fundo do forno. Externamente foi colocada uma estrutura met?lica com espelhos planos para refletir os raios incidentes para o interior do forno, possuindo uma mobilidade para a corre??o do movimento aparente do sol. O seu aspecto primordial ? a viabiliza??o de energia limpa e renov?vel para a sociedade, combatendo os danos ecol?gicos causados pela utiliza??o em larga escala de lenha para a coc??o de alimentos. Os ensaios mostram que o forno chegou ? temperatura m?xima de 123,8?C, assando v?rios alimentos como pizza, bolo, lasanha entre outros em um tempo m?dio de 50 minutos. Comprova-se a viabilidade da utiliza??o do forno. Apresentando ainda condi??es de melhorar seu desempenho com adi??o de novos materiais, equipamentos e t?cnicas
23

Fabrica??o e estudo de um fog?o solar multifocal para coc??o de alimentos

Medeiros J?nior, Aldo Paulino de 10 October 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-02T12:02:51Z No. of bitstreams: 1 AldoPaulinoDeMedeirosJunior_DISSERT.pdf: 2830589 bytes, checksum: e838c6a3026b5cd9757588fa10c784cf (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-06T21:02:12Z (GMT) No. of bitstreams: 1 AldoPaulinoDeMedeirosJunior_DISSERT.pdf: 2830589 bytes, checksum: e838c6a3026b5cd9757588fa10c784cf (MD5) / Made available in DSpace on 2017-02-06T21:02:12Z (GMT). No. of bitstreams: 1 AldoPaulinoDeMedeirosJunior_DISSERT.pdf: 2830589 bytes, checksum: e838c6a3026b5cd9757588fa10c784cf (MD5) Previous issue date: 2016-10-10 / A utiliza??o de materiais comp?sitos tem sido tema de in?meros trabalhos cient?ficos no Brasil e no mundo. A energia solar ? a fonte energ?tica prim?ria e representa a op??o mais ecologicamente vi?vel e a mais social de todas as fontes energ?ticas. Fabricou-se e estudou-se a capacidades e viabilidade de cozimento de um fog?o solar ? concentra??o multifocal com par?bolas refletoras fabricadas em material comp?sito destinado ao cozimento de alimento para fins residenciais, urbanos e rurais. Foi constitu?do de quatro par?bolas fabricadas com materiais comp?sitos, formados por resina ortoft?lica adicionados aos elementos: cortina de tecido, tecido de malha, saco de algod?o e saco de aniagem (juta). A principal caracter?stica do fog?o solar proposto foi a capacidade de coc??o de quatro alimentos simultaneamente, que lhe deu um car?ter de ineditismo tecnol?gico na coc??o de alimentos. Ser?o apresentados os processos de fabrica??o e montagem. A estrutura do fog?o tenha mobilidade de movimento aparente do sol. Representa uma op??o ecol?gica, limpa e renov?vel j? que ? uma alternativa para o uso em larga escala da lenha para o cozimento de alimentos, sendo um grande ajuda para as popula??es menos favorecidas economicamente que n?o param de crescer. Foram demonstradas as viabilidades t?rmicas e econ?micas do fog?o solar proposto para obten??o do cozimento de alimentos. Para demonstrar a viabilidade de utiliza??o do fog?o solar proposto foram cozidos v?rios alimentos da comida t?pica nordestina. Foi comprovada sua capacidade de produzir a coc??o de alimentos de uma refei??o t?pica, arroz, feij?o, macarr?o e carne em apenas uma hora. / The use of composite materials has been the subject of numerous scientific papers in Brazil and worldwide. Solar energy is the primary energy source and the option is more environmentally sustainable and more social of all energy sources. It is manufactured and studied the capabilities and baking feasibility of a solar cooker will multifocal concentration with reflective parabolas made of composite material for the cooking food for residential, urban and rural purposes. It consisted of four parabolas made of composite materials, formed by orthophthalic resin added to the elements: curtain fabric, knitted fabric, cotton bag, burlap sack (jute). The main feature of the proposed solar stove was cooking capacity of four foods simultaneously, which gave him a technological novelty character in cooking. The manufacturing and assembly processes will be presented. The solar cook structure has mobility apparent movement of the sun. It is an environmentally friendly, clean, renewable option since it is an alternative to the large-scale use of firewood for cooking food, and a great help to the disadvantaged populations that do not stop growing. Thermal and economic feasibility of solar cooker proposed for obtaining cooking and baking food have been demonstrated. To demonstrate the feasibility of using solar cooker proposed were cooked various foods of Northeastern typical food. It has proven its ability to produce the cooking of food in a typical meal, rice, beans, pasta and meat in just one hour.
24

Continuity of Care and Medication Adherence among Medicare Beneficiaries

Gediwon N Milky (11769155) 19 December 2021 (has links)
The objectives for this study were to develop a continuity of care scale, to assess the mean level of continuity of care, to assess association between demographic variables and clinical variables with continuity of care, and to assess association between continuity of care and medication adherence among Medicare beneficiaries. A retrospective cohort study was conducted to achieve the objectives using data from the 2015 to 2017 Medicare Current Beneficiaries Survey (MCBS). To be included in the sample, beneficiaries had to have a hyperlipidemia diagnosis, be continuously enrolled in Medicare Part D for six months from start of medication adherence, be continuously enrolled in Medicare Part A and Part B in the preceding year, and had to have at least two prescription claims for hyperlipidemia medications. Beneficiaries were excluded if they had a proxy responder, had an Alzheimer’s disease or dementia diagnosis, were enrolled in Medicare due to end-stage renal disease or disability, or were residing in a long-term care facility. Among 2,120 beneficiaries that met sample selection criteria, 57 percent were aged 75 years or older, 57 percent were female, and 87 percent were White. An overall continuity of care scale was developed using MCBS items that asked respondents about their care experience. Exploratory factor analysis was used to determine subscales of continuity of care using a randomly selected 60 percent of the sample, which yielded three subscales of continuity of care: relational continuity (Factor 1), informational continuity (Factor 2), and management continuity (Factor 3). Confirmatory factor analysis conducted using the remaining 40 percent of the sample validated factor structure of the continuity of care scale. The mean level of overall continuity of care among Medicare beneficiaries was 3.26 out of 4. Medication adherence was assessed using proportion of days (PDC) covered for anti-hyperlipidemia medications. Beneficiaries with a PDC of 80 percent or more were considered medication adherent. Approximately, 81 percent of beneficiaries were adherent to prescribed hyperlipidemia medications. Association between demographic variables and clinical variables with overall continuity of care was assessed using multivariable logistic regression based on purposeful selection of variables method. Older age, low perceived health status, and lower number of prescribed medications were associated with low overall continuity of care. Race and marital status were found to have interaction effect on overall continuity of care. Among non-white beneficiaries, married beneficiaries reported higher overall continuity of care than not-married beneficiaries. Among married beneficiaries, whites reported lower overall 12 continuity of care than non-whites. Association between overall continuity of care and medication adherence was assessed using multivariable logistic regression with purposeful selection of variables method. There was no association found between overall continuity of care and medication adherence.
25

The Study of Network Governance in Continuum of Care (CoC), Homeless Service Networks in the US: Institutional Collective Action Framework

Jeong, Jihoon 12 1900 (has links)
The dissertation investigates the form of network governance in the context of U.S. homeless service networks (namely continuum of care programs; CoCs). This research examines CoC homeless service networks by applying the institutional collective action (ICA) perspectives to understand the forms of network governance as a reflection of network context. The ICA perspective has been applied to understand the rational behavior of network members for the network governance form to mitigate the collective action problems. The ICA perspective helps understand why network members accept specific governance structures with their expectation to maximize the benefits and minimize the costs and uncertainty in their process of collaboration. This dissertation uses the data of CoC networks and point in time data from the U.S. Department of Housing and Urban Development in 2019 and Census. The data developed for this study offers the homeless incidences, geographical characteristics, and governance structure based on the contact information. For an in-depth understanding, interview by CoC leaders was integrated. This dissertation consists of four essays about 1) Literature review on network governance and the theoretical argument in the ICA framework, 2) Background and network governance of the U.S. homeless service networks, 3) Factors affecting the choice of network administrative organization (NAO) form, and 4) Interviews by the representatives of CoC networks. The findings inform us of the governance structure for the effective service provisions and coordination of actions of network members and about why and how network organizations choose a form of network governance.
26

Analyzing the Joint Effects of Network and Community Attributes on Network Performance: Evidence from Local Continuum of Care Homeless Service Networks

Kim, Jintak 12 1900 (has links)
This dissertation examines the factors and combinations of factors that affect the performance of continuum of care homeless service networks, applying the configurational approach of contingency theory to data sets drawn from federal sources. The study accepts the two key assumptions from the theory: (1) that there are multiple paths to high performance and (2) key conditions have a joint influence on network performance. The data analysis in this study has two parts. The first employs OLS regression to examine the causal relationship between independent variables and the performance of permanent supportive housing (PSH) programs. This study also applies fuzzy set qualitative comparative analysis (fsQCA) to identify multiple combinations of factors that influence the performance of PSH programs. The results identify key factors and multiple combinations of factors that lead to high and low network performance. Federal CoC funding emerges as a core condition for high and low performance, but all relevant conditions can be critical factors depending on how they interact with other relevant conditions. This analysis helps expand the utility of existing contingency theory by using it to explain the dynamic interactions between factors in the context of public service networks. Ultimately, this dissertation confirms that fsQCA can be a useful method for evaluating the performance of public service networks and helping them provide more services more effectively.
27

Institucionální struktura sportu České republiky / Institutional structure of sport in the Czech republic

Tužová, Lucie January 2014 (has links)
Title: Institutional structure of sport in the Czech republic Objectives: The main goal of this project is to evaluate current role of the Czech Sport Union and the Czech Olympic Commitee and their position in the structure of czech sport environment. The second goal is, on the basis of research, to suggest a new concept of the institutional structure of sport in the Czech republic and at the same time considering the importance of scientific and educational center. Methods: In this project, there was used a qualitative method of research - in-depth interview, which was completed by semi-structured questionnaire. As well as a method of text analysis was applied. Case study served as a certain source of secondary data too. Results: Recommendations and proposals for improvement of situation of the czech sport environment represent the main output. Transcriptions of in-depth interviews placed in appendix are considered as a significant results as well. This thesis is going to be submitted to all of respondents with the aspiration to inform the whole sport environment about current situation in the czech sport area. Key words: Roles of state, competences of COC a CSU, cooperation of sport environment, sport organizational structure, scientific and educational institute.
28

Par?metros de adaptabilidade e estabilidade para produ??o de gr?os, teores de prote?nas e minerais em feij?o-caupi (vigna unguiculata (l.) walp.) no semi?rido brasileiro

Da Silva, Danillo Oleg?rio Matos 16 March 2018 (has links)
Submitted by Verena Pereira (verenagoncalves@uefs.br) on 2018-07-17T21:59:57Z No. of bitstreams: 1 Tese Final_ Danillo Olegario.pdf: 8604713 bytes, checksum: 2e0a9905d4de264fbbd3a8997c3babb3 (MD5) / Made available in DSpace on 2018-07-17T21:59:57Z (GMT). No. of bitstreams: 1 Tese Final_ Danillo Olegario.pdf: 8604713 bytes, checksum: 2e0a9905d4de264fbbd3a8997c3babb3 (MD5) Previous issue date: 2018-03-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The goals of this work were to compare and evaluate statistical methods of analysis of adaptability and stability for total protein, minerals and grain yield in cowpea lines, as well as retention of these nutrients after cooking to enable recommendation and registration of new cultivars for the Brazilian semiarid. Forty-four genotypes, distributed in two experiments of different population densities, were evaluated in seven environments, in the states of Bahia, Cear?, Pernambuco and Piau?. Initially, a comparison was made of ten statistical methods of adaptability and stability using only the production data. Spearman correlation coefficients were estimated between the methods. For the assessments of adaptability and stability of the genotypes the methods of Eberhart and Russell, Lin and Binns and the Model of main additive effects and multiplicative interaction - AMMI were applied. To evaluate the effect of cooking, 24 genotypes were used, including ten lines, five commercial cultivars and nine landraces maintained by farmers. The seed protein content was quantified through the Kjeldahl method. and the minerals by the AOAC standard procedure. The statistical analyzes for the experimental designs were performed in the SAS by the GLM procedure. The AMMI method is most suitable due to the graphical arrangement of both the genotypes and the environments and high correlation with others evaluated methods. The use of highly correlated methods is not recommended, as in the cases of Plaisted and Peterson and Wricke and the methods of Annicchiarico and Lin and Binnsthat show strong association and produce similar genotypic classifications. The use of one of them incombination with that of Eberhart and Russell or AMMI can add information to the stability analysis. Statistically significant differences in the genotype as well as in the genotype?environment interaction for minerals, proteins and grain yield were observed in all the assays. The lines presenting the highest protein contents showed the lowest grain yields, and it indicated the prominent ?phenotypic cost? of protein in overall cowpea seed production. The methods by Eberhart and Russell, Lin and Binns and AMMI showed similar results for selection of superior genotypes. For the protein content, the lines C3Q, C3M, C2S and C1J presented grain yields equal to or greater than the general mean of the experiments and average of 27% of protein. For iron and zinc contents, the line C4I and T16_2R presented grain yield equal to or greater than the general mean of the experiments, with mean values of Fe and Zn 15% higher than the values of the evaluated cultivars. For the potassium and calcium contents, the C4I and C3O strains showed grain yield equal to or greater than the general average, with K and Ca means higher than the values of the cultivars evaluated. All the lines mentioned above presented broad adaptability and good stability in the series of evaluated environments showing great potential to be released as new cultivars for the Brazilian semiarid. Cooking had a reduced effect on protein, potassium, calcium, iron and zinc contents in the cowpea beans. The CPCR3F6L17 obtained high grain yield and high levels of protein, potassium, iron and zinc, after cooking, being promising for the region studied / Os objetivos deste trabalho foram comparar e avaliar m?todos estat?sticos de an?lise de adaptabilidade e estabilidade para o teor de prote?nas totais, minerais e produ??o de gr?os em linhagens de feij?o-caupi, bem como a reten??o desses nutrientes ap?s a coc??o, para possibilitar a recomenda??o e registro de novos cultivares para o semi?rido brasileiro. Quarenta e quatro gen?tipos, distribu?dos em dois experimentos de diferentes densidades populacionais, foram avaliados em sete ambientes, nos estados da Bahia, Cear?, Pernambuco e Piau?. Inicialmente, foi realizado acompara??o de dez m?todos estat?sticos de adaptabilidade e estabilidade utilizando apenas dados de produ??o. Coeficientes de correla??o Spearman foram estimados entre os m?todos. Para as avalia??es de adaptabilidade e estabilidade dos gen?tipos aplicou-se os m?todos de Eberhart e Russell, Lin e Binns e o Modelo de efeitos aditivos principais e intera??o multiplicativa - AMMI. Para avaliar o efeito da coc??o, foram utilizados 24 gen?tipos, sendo dez linhagens, cinco cultivares comerciais e nove variedades mantidas por agricultores.A quantifica??o de prote?na total foi realizada pelo m?todo de Kjeldhal, e os minerais pelo procedimento padr?o da AOAC. As an?lises estat?sticas para os delineamentos experimentais foram efetuadas no SAS pelo procedimento GLM. O m?todo AMMI ? o mais indicado devido a disposi??o gr?fica e alta correla??o com os demais m?todos. A utiliza??o de m?todos que apresentam elevada correla??o, como os m?todos Plaisted e Peterson e Wricke, Annicchiarico e Lin e Binns, que mostram forte associa??o, e produzem classifica??es genot?picas similares, n?o ? recomendado. O uso de um deles em combina??o com o de Eberhart e Russell ou AMMI pode agregar informa??o ? an?lise de estabilidade. Foram observadas diferen?as estat?sticas significativas dos quadrados m?dios de tratamentos, dos ambientes e das intera??es ambientes x tratamentos para minerais, prote?nas e produ??o de gr?os. As linhagens que apresentaram os maiores teores de prote?na e minerais apresentaram produ??es de gr?os abaixo da m?dia geral, nos dois experimentos. Os m?todos de Eberhart e Russell, Lin e Binns e o AMMI apresentam resultados semelhantes quanto a sele??o de gen?tipos superiores. Para o teor de prote?na, As linhagens C3Q, C3M, C2S e C1J apresentaram produ??es de gr?os igual ou superior a m?dia geral dos experimentos e m?dia de 27% de prote?na. Para os teores de ferro e zinco, a linhagem C4I e T16_2R apresentou produ??o de gr?os igual ou superior a m?dia geral dos experimentos, com valores m?dios de Fe e Zn, 15% superiores aos valores dos cultivares avaliados. Para os teores de pot?ssio e c?lcio, as linhagens C4I e C3O mostraram rendimento de gr?os igual ou maior do que a m?dia geral, com m?dia de K e Ca mais elevadas do que os valores dos cultivares avaliados. Todas as linhagens citadas anteriormente apresentaram ampla adaptabilidade e boa estabilidade na s?rie de ambientes avaliados mostrando grande potencial para serem lan?ados como novos cultivares para o semi?rido brasileiro. A coc??o teve efeito reduzido nos teores de prote?na, pot?ssio, c?lcio, ferro e zinco, nos gr?os de feij?o-caupi. A linhagem CPCR3F6L17 obteve alta produtividade de gr?os e elevados teores de prote?na, pot?ssio, ferro e zinco, ap?s a coc??o, mostrando-se promissora para a regi?o estudada
29

Miniaturisation de la séparation Uranium / Plutonium / Produits de Fission : conception d'un microsystème " Lab-on-cd " et application

Bruchet, Anthony 18 October 2012 (has links) (PDF)
L'analyse chimique est indispensable à de nombreuses étapes de la mise au point et dusuivi des procédés de retraitement des combustibles nucléaires usés, de la gestion des déchetsnucléaires, ou encore de l'optimisation des combustibles du futur. Le cycle global d'analysecomprend généralement plusieurs étapes de séparations chimiques longues, manuelles etdifficiles à mettre en oeuvre en raison de leur confinement en boite à gants. Il apparaîtaujourd'hui nécessaire de proposer des solutions innovantes et viables dans le butd'automatiser ces étapes mais aussi de réduire le volume de déchets radioactifs en fin de cycleanalytique. Une solution est alors la conception de plateformes analytiques miniaturiséesautomatisées et jetables.L'objectif de cette thèse est de concevoir un système miniaturisé alternatif à lapremière étape actuelle d'analyse des combustibles usés séparant, par chromatographied'échange d'ions, l'Uranium et le Plutonium des autres éléments constituant l'échantillon. Cesystème doit permettre à la fois de conserver les performances analytiques du processusactuel, de réduire drastiquement l'exposition des expérimentateurs par l'automatisation, ainsique le volume de déchets produits en fin de cycle analytique. Ainsi, la séparation a étéimplantée sur un microsystème jetable en plastique (COC), au design spécialement adapté àl'automatisation : un lab-on-CD.Le prototype développé intègre une micro-colonne séparative d'échange d'anionsremplie d'un polymère monolithique dont la synthèse in-situ ainsi que la fonctionnalisation desurface ont été optimisées spécifiquement pour la séparation voulue. Le développement duprotocole de séparation adapté à ces micro-colonnes a été réalisé à l'aide d'un outil desimulation de l'élution des différents éléments d'intérêts. Cet outil permet de prévoir lagéométrie de la colonne (section et longueur) afin d'obtenir, en fonction de l'échantillon, desfractions de collecte de l'Uranium et du Plutonium pures.Finalement, le prototype actuel est capable de conduire simultanément 4 séparationsde façon automatisée et permet de réduire à la fois le nombre de manipulations, le tempsd'analyse mais aussi de diviser approximativement par 1000 le volume des déchets liquidesgénérés.
30

Développement d'une plateforme analytique jetable basée sur l'isochophorèse pour la séparation et la caractérisation isotopique des lanthanides / Development of a micro total analytic system based on isotachophoresis for the separation and characterization of lanthanides

Vio, Laurent 06 December 2010 (has links)
La caractérisation juste et reproductible en isotopie et en concentration des radioéléments est l’une des thématiques essentielles des laboratoires d’analyse dans le domaine du nucléaire. Afin de minimiser les temps de manipulation en boite à gants des personnels et la production de déchets radioactifs liés à l’analyse de combustibles nucléaires, il est nécessaire de proposer des solutions efficaces et innovantes. Depuis quelques années, la miniaturisation des systèmes séparatifs constitue l’un des axes de développement majeurs de la chimie analytique et ces microsystèmes constituent certainement une des solutions pour répondre aux exigences de l’analyse nucléaire. Ce travail a pour objectif la conception d’une plateforme analytique miniaturisée et à usage unique, dédiée a la séparation des lanthanides, issus des combustibles usés, en amont de leur analyse par spectrométrie de masse. Destiné à remplacer une étape de séparation chromatographique au centre d’un processus analytique de trois étapes, le nouveau protocole basé sur l’isotachophorèse (ITP) doit satisfaire un cahier des charges précis. Les propriétés de complexation des lanthanides ont d’abord été exploitées afin d’obtenir avec un agent chélatant unique et rigoureusement sélectionné, l’acide 2-hydroxy-2-methylbutyrique (HMBA), la sélectivité intra période nécessaire à leur séparation complète par ITP. Basées sur des modèles théoriques existants, des études complémentaires, notamment des paramètres influençant la résolution, ont permis l’amélioration des performances globales du système ainsi que son dimensionnement. Pour réduire drastiquement le volume de déchets liquides secondaires (solutions de rinçage) et la manipulation de matériaux et de matériels radioactifs, le protocole a été implanté sur un microsystème polymérique jetable en COC, spécialement développé pour cette application. Ce microsystème a ensuite été couplé à un spectromètre de masse a multi collection et source à plasma à couplage inductif pour mesurer les rapports isotopiques / The accurate and reproducible characterization of radioactive solutions in isotope composition and concentration is an essential topic for analytical laboratories in the nuclear field. In order to reduce manipulation time in glove box and production of contaminated wastes, it is necessary to propose innovative and efficient solutions for these analyses. Since few years, microchips are a major field of development in analytical chemistry and those devices could provide a solution which fits the needs of nuclear industry. The aim of this work is to design a disposable analytical micro-device devoted to lanthanide separation from spent nuclear fuel before their analysis in mass spectrometry. Designed to be used in place of a separation process by liquid chromatography which is involved in a three step protocol, the new protocol based on isotachophoresis (ITP) keeps compatible with the other two steps. The complete separation of lanthanides by ITP was obtained by the use of only one chelating compound rigorously selected: the 2-hydroxy 2-methyl butyric acid (HMBA). The main parameters involved in solute resolution were defined from the theoretical models of ITP and experimental studies of the influence of these parameters allowed to optimize the geometry of the system and to improve its performances. To suppress cleaning of the system and, consequently, to strongly reduce both liquid waste volume and handling radioactive material, the ITP protocol was transferred in a polymeric (COC) disposable microchip especially developed for this purpose

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