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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.
91

QR CODE ACCESSED VIDEO-BASED INSTRUCTION TO TEACH VOCATIONAL SKILLS TO STUDENTS WITH MODERATE TO SEVERE DISABILITIES

Barnett, Lora N. 01 January 2018 (has links)
The purpose of this study was to determine the effects of QR code (quick reference) linked video-based instruction (VBI) on daily vocational skills for students with moderate to severe disabilities (MSD). A multiple probe across participants was used to evaluate the effectiveness of VBI accessed through scanning a QR code. During technology training a system of least prompts was used to teach students to unlock the iPod, scan the QR code, press play, and press pause between each step of the task; after reaching mastery, students entered into the intervention condition (VBI). During VBI an immediate change in level was observed across three particpants. This study found a functional relationship between VBI and the completion of vocational tasks.
92

African university students, the five factor model, and parental bonding : prediction of alcohol use

Mhlongo, Mpumelelo Marcel 23 August 2008 (has links)
Thesis (M.Ed.) (Clinical Psychology) --University of Limpopo, 2008. / There is a considerable literature linking aspects of personality, parenting, and risk behaviors such as alcohol abuse. Three hundred African university students participated in a study of the relationship between personality, assessed with the NEO PI-R (Costa & McCrae, 1992), and alcohol use. Personality traits did not predict alcohol use among the students. It was also predicted that the Parental Bonding Instrument (PBI; Parker, Tupling, & Brown, 1979) would mediate the relationship between personality and alcohol use. Results of the current study revealed no significant relationship between parenting and alcohol use. The results are discussed with regards the use of the NEO PI-R’s validity in the population used. Keyword: Five Factor Model; Parental bonding; Abstainers; Moderate drinkers; Heavy drinkers. / N/A
93

Finns det några skillnader mellan Socialdemokraterna och Moderaterna? : en studie om kommunalt självstyre på lokal och nationell nivå / Are there any differences between the Social Democratic Party and the Moderate party? : a study of municipal self-government at local and national level

Björkman, Emma January 2002 (has links)
<p>The Social Democratic Party and the Moderate Party are two parties with different ideological background. The parties have different opinions in issues of public and private matters. The Social Democratic Party profiles it self, through the local and national party programs, as a party for solidarity and security. The Moderate Party, on the other hand, profiles it self through their programmes as a party with a possibility for the individual to shape his or her own life. Through a survey on members in the local government, and two key persons at national level, the view of municipal self-government has appeared. The party programmes constitute a platform for the parties´ views on municipal self-government. These views have been put together with the result of the survey. Urban Strandberg has designed an analysis frame related to municipal self-government. His concept, municipalities’ basic character, board of directors and administration, is the theoretical foundation of the thesis. The content of the Party programmes and the results of the survey are thendiscussed within the frame of Strandbergs concept and Demokratiutredningens rapport SOU 2000:1. From the collective perspective of the theory, the content of party programmes and the result of the survey an image of the parties’ views on municipal self-government starts to grow. Within each party respectively, they keep a common strategy in important issues, which the local governments and the parties’ basic characters have raised. There are dividing lines due to the administration of the municipalities. Civic participation unites the parties in ideological issues. The opinions, in the issue of municipal self-government, differs between the Social Democratic Party and the Moderate Party. The reason for that is because of their fundamental different views in the fields of social order and ideology, as it is described in the party programmes. In reality when the parties shape the politics they cannot profile themselves as much as in the"vision"in their party programmes. The parties have to find a middle course, which is reflected in the answers from some of the respondents.</p>
94

'Vi' och 'dem' : -En diskursanalys av konstruktionen av gruppidentitet hos Moderaterna, Sverigedemokraterna och Vänsterpartiet

Sunneborn, Pierre January 2013 (has links)
The aim of this essay is to show if and how group identities are being constructed in maindocuments from three political parties in the Swedish parliament, focusing on class, genderand ethnic identities. The three parties who’s documents are being analyzed are theModerate Party, the Sweden Democrats and the Left Party. The conclusion of the essay isthat the Moderate Party is so focused on the individual that they are not promoting groupidentity based on class, gender or ethnicity. The Sweden Democrats are mostly discussing,and therefore creating a discourse of, cultural identity, where Swedish, Nordic, Europeanand Western culture are being created as the ‘us’, and others are being created as ‘them’.They are also promoting difference between men and women, therefore dividing the sexesin groups. The Left Party are focused on class, and are dividing people in working class (themajority) and the elite (the minority). They are also creating a ‘us’ and ‘them’ whilediscussing the patriarchy, a system in which the man is superior and the woman is inferior.
95

Barnfattigdom i Sverige, finns den? : En studie om Socialdemokraternas och Moderaternas välfärdspolitik mot den svenska fattigdomen sedan 1960-talet / Child Poverty in Sweden, does it exist? : A study of the Welfare Policy of the Swedish Social Democratic Party and the Moderate Party and the Poverty in Sweden since the 1960's

Ekström Olsson, marie January 2012 (has links)
This essay is regarding the problematic facts about child poverty in Sweden. Since the beginning of the new millennium child poverty has increased, in Sweden. The last report which came out in the spring this year (2012) opened up for a lively political debate as well as big headlines in news papers and other media. The attention it got in Society became hard for the politicians to avoid. The Swedish section of Save the Children, demanded in their report concerning child poverty in Sweden that the Swedish Government need to do an inquiry about the increasing child poverty.    Today in Sweden, there are two big parties, and they have been the biggest for a long time now. The two are Socialdemokraterna and Moderata Samlingspartiet. The first mentioned one is representing a socialist policy whilst the second one is representing a right-wing party. This study will deal with whether the parties have changed over time or not. The big question will be whether they have changed their opinions and positions since the beginning of 1960. This year is chosen in particular because it was during this period the largest development of the welfare state of Sweden started. It will be about if the parties changed according to, in particular poverty in Sweden. There are two main questions that I intend to answer throughout the text, to finally analyze the questions in the last part of this essay.
96

Analyse de la vulnérabilité du bati existant. Estimation et réduction des incertitudes dans l'estimation des dommages et des pertes pour un scénario sismique donné / Seismic vulnerability analysis of existent buildings. Loss estimation and uncertainty analysis for deterministic earthquake scenarios.

Riedel, Ismaël 08 July 2015 (has links)
Parmi les risques naturels et les catastrophes majeures, les tremblements de terre sont l'un des plus meurtriers, préjudiciables et imprévisibles de tous. Avec une constante augmentation de l'impact dans les économies des pays et dans le nombre de victimes, les tremblements de terre modernes coûtent des dizaines de milliards de dollars et tuent en moyenne 35000 personnes par an dans le monde.Avec l'étendue des dommages observés après les tremblements de terre d'intensité modérée à forte de ces dernières décennies, la sensibilisation auprès des catastrophes naturelles a considérablement augmenté. Il y a donc une demande croissante d'analyses détaillées des risques sismiques pour renforcer la préparation en amont et mieux planifier la réponse après les séismes. Cette évaluation des risques nécessite non seulement l'estimation de l'aléa sismique, mais aussi la représentation de la capacité des structures à résister face au mouvement du sol: tel est l'objectif des évaluations de la vulnérabilité sismique. En raison de la complexité inhérente à l'estimation de l'aléa, des vulnérabilités et leur interaction, la quantification du risque sismique est une tâche ardue, et estimer des impacts réalistes dus aux grands tremblements de terre ne peut se faire qu'approximativement.L'estimation de la vulnérabilité sismique des bâtiments à l'échelle urbaine, étant un élément crucial dans l'évaluation des risques, est elle-même une tâche longue, coûteuse et compliquée, en particulier dans les régions où l'aléa sismique est modéré à faible et où la mobilisation des ressources pour l'évaluation sismique est réduite même si le risque est non négligeable.Nous proposons dans la première partie de cette étude un moyen d'effectuer une estimation rapide à l'aide des données fiables du bâtiment. Ces données sont plus facilement disponibles au niveau régional que l'information habituellement exigée par les méthodes traditionnelles. Avec l'utilisation d'un ensemble de données du bâtiment existant à Grenoble (France), avec une classification EMS98 de la vulnérabilité, et en employant deux techniques de fouille de données différentes - Association Rule Learning et Support Vector Machine - nous avons développé des proxies de la vulnérabilité sismique. Ceux-ci ont été appliqués à la France entière en utilisant des informations de base à partir de bases de données nationales (information de recensement) et les données issues du traitement des images satellites et des photographies aériennes pour produire une carte de la vulnérabilité à l'échelle nationale. Cette méthode macroscopique pour évaluer la vulnérabilité est facilement applicable dans le cas d'un manque d'informations concernant les caractéristiques structurelles du parc immobilier.La partie qui clôture ce travail est préconisée pour le calcul des pertes liées aux tremblements de terre et à l'analyse et la réduction des incertitudes. L'estimation complète des scénarios de tremblement de terre avec un nombre probable de bâtiments endommagés dans une ville européenne typique est présentée par la suite. Une analyse complète des incertitudes est réalisée à chaque étape, et l'incertitude combinée finale est calculée. Les principales sources de variabilité sont représentées. Dans la dernière partie, l'évolution des dommages et des risques lorsque des améliorations structurelles sont affectées aux bâtiments est examinée. Des évaluations des pertes économiques sont effectuées pour la France en utilisant des cartes de risques réglementaires pour des différentes périodes de retour. En particulier, pour cinq villes françaises, le modèle de perte proposé est utilisé pour concevoir un plan de réaménagement et de modernisation du parc immobilier en réalisant des études coûts-bénéfices pour les différents types de plans d'intervention structurelle. Des scénarios d'investissements optimaux sont calculés, qui peuvent servir d'appui aux décisions stratégiques concernant l'atténuation du risque sismique en France. / Among the natural hazards and major catastrophes, earthquakes are one of the most deadly, damaging and unpredictable of all. With increasing impacts in countries' economies and casualties, modern earthquakes cost in average tens of billons of dollars and kill 35,000 people per year worldwide (USGS). The planet is experiencing the consequences of the large urban population growth of the last century.With the extensive damage observed after the moderate-to-strong earthquakes of the last decades, awareness of natural catastrophes has considerably increased. There is therefore, a growing demand for detailed seismic risk analysis to strengthen disaster risk mitigation and response. This risk assessment requires not only the estimation of the seismic hazard, but also the representation of the structures' capacity to withstand the seismic ground motion: this is the objective of seismic vulnerability assessments.Due to the inherent complexity of estimating hazard, vulnerabilities and their interaction, seismic risk quantification is a daunting task and estimating realistic impacts due to large earthquakes may only be done approximately.The estimation of the seismic vulnerability of buildings at an urban scale, while a crucial element in any risk assessment, is itself an expensive, time-consuming, and complicated assignment, especially in moderate-to-low seismic hazard regions where the mobilization of resources for the seismic evaluation is reduced, even if the hazard is not negligible. We propose in the first part of this study a way to perform a quick estimation using convenient, reliable building data that are readily available regionally instead of the information usually required by traditional methods. Using a dataset of existing buildings in Grenoble (France) with an EMS98 vulnerability classification and by means of two different data mining techniques - association rule learning and support vector machine - we developed seismic vulnerability proxies. These were applied to the whole France using basic information from national databases (census information) and data derived from the processing of satellite images and aerial photographs to produce a nationwide vulnerability map. This macroscale method to assess vulnerability is easily applicable in case of a paucity of information regarding the structural characteristics and constructional details of the building stock.The closing part of this work is advocated to the calculation of earthquake losses and to the analysis and reduction of uncertainties. A comparison between predicted and observed ground motions and intensities in France is presented, and prediction equations producing the smallest residuals are highlighted. The full estimation from earthquakes scenarios to probable number of damaged buildings in a typical European city is presented afterwards. A comprehensive analysis of uncertainties is carried on at every step, and the final combined uncertainty is calculated. The major sources of variability are depicted and recommendations on how to efficiently reduce them are proposed. In the last part, the evolution of damage and risk when structural improvements are performed to buildings is reviewed. Economic loss assessments are performed for France using regulatory hazard maps for different time horizons. In particular, for five French cities the proposed loss model is used to design retrofitting schemes by carrying out cost-benefit studies for different types of structural intervention plans. Optimal investment scenarios are calculated, which may support strategic decisions regarding the risk mitigation in France.
97

Aplicação de diferentes tecnologias na extração de pectina presente na casca do maracujá

Oliveira, Cibele Freitas de January 2015 (has links)
O presente trabalho teve como objetivo estudar o potencial de diferentes tecnologias na extração de pectina da casca do maracujá e está dividido em quatro etapas. A primeira etapa do trabalho consistiu em realizar a obtenção e caracterização da farinha da casca do maracujá por diferentes métodos de secagem (estufa a 60 ºC com circulação de ar e liofilização). Os resultados desta primeira etapa mostraram que a farinha da casca do maracujá, obtida por ambos os tratamentos de secagem, apresentou elevado conteúdo de fibras alimentares totais (63,98-72,62 % b.s) e conteúdo de pectina, que variou entre 6,98 e 19,6 % (b.s). O conteúdo de pectina foi maior para a amostra liofilizada e esses coprodutos apresentaram capacidade de retenção de água entre 6,30 e 14,9 g água/g amostra e capacidade de retenção de óleo que variou entre 2,6 e 6,5 g óleo/g amostra, sendo os maiores valores para as amostras liofilizadas. A segunda etapa do trabalho teve como objetivo estudar a extração da pectina assistida pela tecnologia de campo elétrico moderado e compará-la com a extração convencional da pectina. Para isso, diferentes condições de tempo de extração, temperatura, pH e tensão do campo elétrico moderado foram aplicadas na farinha da casca do maracujá. O rendimento de extração de pectina foi de 6,20 % (b.s) quando as condições de extração foram pH 2,0, razão sólido:líquido 1:30, 100 V, 50 °C e 15 min; para as mesmas condições sem o uso do campo elétrico moderado o rendimento obtido foi de 4,80 % (b.s). Na terceira etapa, a pesquisa foi voltada para a extração da pectina assista por alta pressão hidrostática. Para a realização dos ensaios dois planejamentos experimentais foram realizados. O primeiro planejamento consistiu em determinar as melhores condições de temperatura e pressão para a extração da pectina que, posteriormente, foram utilizadas como pré-tratamento para a extração convencional. O segundo planejamento foi realizado para determinar as melhores condições de tempo e temperatura da extração convencional, utilizando a alta pressão como pré-tratamento. Foi observado que a alta pressão hidrostática, combinada com temperatura moderada (300 MPa e 50 ºC ), tem potencial para ser utilizada como pré-tratamento na extração convencional, levando a um rendimento de extração de pectina de 14,34 %. Por fim, a última etapa do presente trabalho foi a extração da pectina assistida por ultrassom, tendo sido desenvolvido um planejamento experimental com duas variáveis, temperatura e intensidade de potência do ultrassom. Os resultados desta etapa demostraram que um maior rendimento de extração (12,67 % b.s) foi obtido na maior temperatura e intensidade de potência, 85 ºC e 664 W/cm2, respectivamente. Os resultados demostraram que a pectina tem potencial para ser melhor extraída da casca de maracujá com o uso das tecnologias emergentes empregadas neste trabalho, pois obteve-se um maior rendimento de extração em menor tempo de processo, quando comparada com a extração convencional. / The aim of this work was to study the potential of different technologies for extraction of pectin from passion fruit peel. The work is divided in four steps. The first step was performed to obtain and characterize the passion fruit peel powder by convective hot air-drying at 60 ºC and freeze-drying. The results showed that the passion fruit powder obtained by different methods of dehydration, had a high content of dietary fiber (63.98-72.62 % d.m) and the content of pectin ranged between 6.98 from 19.6 % (d.m). The content of pectin was high in freeze-dried samples. In addition, these fiber-rich co-products have potential applications as ingredients in products requiring hydration and viscosity development due to their high total dietary fiber content and good technological proprieties, especially their water holding (6.30-14.9 g H2O/g) and oil holding capacities (2.6–6.5 g oil/g), especially for the freeze-dried samples. The purpose of the second step was to explore the conventional and moderate electric field extractions of pectin from passion fruit peel. Different conditions of time, pH, temperature and voltage were applied. The extraction yield of pectin was 6.20 % (d.m) when the extraction conditions were pH 2.0, solid:liquid ratio 1:30, 100V, 50 ºC and 15 minutes; for the same conditions, without moderate electric field, the yield was 4.80 % (b.s). In the third step, the aim was to investigate the potential of high pressure to extract the pectin from passion fruit peel. Two experimental designs were performed; the first was used to determine the optimal conditions of pressure and temperature for pectin extraction and use these conditions as a pre-treatment for conventional extraction. The second experimental design was performed to determine the best conditions of the time and temperature using high pressure as a pre-treatment. The results showed that the yield of extraction enhance twice (7.4 to 14.34 %) when high pressure (300 MPa and 50 ºC) was used as a pre-treatment, using the same conditions of conventional extraction. Finally, the last step of this work was to explore the pectin extraction assisted by ultrasound using an experimental design. The independent variables were temperature and power intensity. The highest yield (12.67 %) of pectin was obtained using power intensity of 644 W/cm2 and temperature of 85 ºC. The results showed that the pectin from passion fruit peel can be extracted using emerging technologies, since the yield of extraction was high in less time comparing with conventional extraction.
98

Enhancement of academic engagement of students with  intellectual disability using peer support interventions : A systematic literature review

Eberli, Ramona January 2018 (has links)
Children with intellectual disabilities (ID) in inclusive classrooms differ in ways of processing information and learning speed compared to their peers without disabilities. Therefore teaching methods must be adapted to their individual needs. Peer support is seen as an additional form of improving students’ academic engagement. This systematic review focuses on peer supported interventions which facilitate academic engagement of children and youth with mild to profound ID. It contains six studies, which met pre-determined inclusion criteria focusing specifically on academic engagement. The studies were analysed to examine (a) different types of peer support, (b) peer support characteristics, (c) definition of academic engagement of students with ID and (d) if a change in academic engagement as an outcome can be evaluated after a peer support intervention. In this review, the data of 18 students with mild to profound ID and their peers in the age of 8 to 17 years, were included. Four different types of peer support intervention were identified, which included different characteristics mostly focussing on supporting students’ communication, access to information and active participation in class. The different definitions of academic engagement which were found hindered comparison of results. Nevertheless, all studies had a positive effect on the academic engagement of students with ID. Future research is needed to investigate the long-term impact of different types of peer support on academic engagement of students with ID and their need in relation to specific forms of ID.
99

Aplicação de diferentes tecnologias na extração de pectina presente na casca do maracujá

Oliveira, Cibele Freitas de January 2015 (has links)
O presente trabalho teve como objetivo estudar o potencial de diferentes tecnologias na extração de pectina da casca do maracujá e está dividido em quatro etapas. A primeira etapa do trabalho consistiu em realizar a obtenção e caracterização da farinha da casca do maracujá por diferentes métodos de secagem (estufa a 60 ºC com circulação de ar e liofilização). Os resultados desta primeira etapa mostraram que a farinha da casca do maracujá, obtida por ambos os tratamentos de secagem, apresentou elevado conteúdo de fibras alimentares totais (63,98-72,62 % b.s) e conteúdo de pectina, que variou entre 6,98 e 19,6 % (b.s). O conteúdo de pectina foi maior para a amostra liofilizada e esses coprodutos apresentaram capacidade de retenção de água entre 6,30 e 14,9 g água/g amostra e capacidade de retenção de óleo que variou entre 2,6 e 6,5 g óleo/g amostra, sendo os maiores valores para as amostras liofilizadas. A segunda etapa do trabalho teve como objetivo estudar a extração da pectina assistida pela tecnologia de campo elétrico moderado e compará-la com a extração convencional da pectina. Para isso, diferentes condições de tempo de extração, temperatura, pH e tensão do campo elétrico moderado foram aplicadas na farinha da casca do maracujá. O rendimento de extração de pectina foi de 6,20 % (b.s) quando as condições de extração foram pH 2,0, razão sólido:líquido 1:30, 100 V, 50 °C e 15 min; para as mesmas condições sem o uso do campo elétrico moderado o rendimento obtido foi de 4,80 % (b.s). Na terceira etapa, a pesquisa foi voltada para a extração da pectina assista por alta pressão hidrostática. Para a realização dos ensaios dois planejamentos experimentais foram realizados. O primeiro planejamento consistiu em determinar as melhores condições de temperatura e pressão para a extração da pectina que, posteriormente, foram utilizadas como pré-tratamento para a extração convencional. O segundo planejamento foi realizado para determinar as melhores condições de tempo e temperatura da extração convencional, utilizando a alta pressão como pré-tratamento. Foi observado que a alta pressão hidrostática, combinada com temperatura moderada (300 MPa e 50 ºC ), tem potencial para ser utilizada como pré-tratamento na extração convencional, levando a um rendimento de extração de pectina de 14,34 %. Por fim, a última etapa do presente trabalho foi a extração da pectina assistida por ultrassom, tendo sido desenvolvido um planejamento experimental com duas variáveis, temperatura e intensidade de potência do ultrassom. Os resultados desta etapa demostraram que um maior rendimento de extração (12,67 % b.s) foi obtido na maior temperatura e intensidade de potência, 85 ºC e 664 W/cm2, respectivamente. Os resultados demostraram que a pectina tem potencial para ser melhor extraída da casca de maracujá com o uso das tecnologias emergentes empregadas neste trabalho, pois obteve-se um maior rendimento de extração em menor tempo de processo, quando comparada com a extração convencional. / The aim of this work was to study the potential of different technologies for extraction of pectin from passion fruit peel. The work is divided in four steps. The first step was performed to obtain and characterize the passion fruit peel powder by convective hot air-drying at 60 ºC and freeze-drying. The results showed that the passion fruit powder obtained by different methods of dehydration, had a high content of dietary fiber (63.98-72.62 % d.m) and the content of pectin ranged between 6.98 from 19.6 % (d.m). The content of pectin was high in freeze-dried samples. In addition, these fiber-rich co-products have potential applications as ingredients in products requiring hydration and viscosity development due to their high total dietary fiber content and good technological proprieties, especially their water holding (6.30-14.9 g H2O/g) and oil holding capacities (2.6–6.5 g oil/g), especially for the freeze-dried samples. The purpose of the second step was to explore the conventional and moderate electric field extractions of pectin from passion fruit peel. Different conditions of time, pH, temperature and voltage were applied. The extraction yield of pectin was 6.20 % (d.m) when the extraction conditions were pH 2.0, solid:liquid ratio 1:30, 100V, 50 ºC and 15 minutes; for the same conditions, without moderate electric field, the yield was 4.80 % (b.s). In the third step, the aim was to investigate the potential of high pressure to extract the pectin from passion fruit peel. Two experimental designs were performed; the first was used to determine the optimal conditions of pressure and temperature for pectin extraction and use these conditions as a pre-treatment for conventional extraction. The second experimental design was performed to determine the best conditions of the time and temperature using high pressure as a pre-treatment. The results showed that the yield of extraction enhance twice (7.4 to 14.34 %) when high pressure (300 MPa and 50 ºC) was used as a pre-treatment, using the same conditions of conventional extraction. Finally, the last step of this work was to explore the pectin extraction assisted by ultrasound using an experimental design. The independent variables were temperature and power intensity. The highest yield (12.67 %) of pectin was obtained using power intensity of 644 W/cm2 and temperature of 85 ºC. The results showed that the pectin from passion fruit peel can be extracted using emerging technologies, since the yield of extraction was high in less time comparing with conventional extraction.
100

Estudo de técnicas de extração de saponinas do fruto de erva mate (Ilex paraguariensis St. Hill)

Silva, Caroline Garcia Finkler da January 2016 (has links)
O grande acúmulo de saponinas nos frutos imaturos de erva mate permite considerá-los uma fonte de matéria prima abundante e ainda não explorada para obtenção de saponinas. As saponinas são conhecidas como tensoativos naturais, sendo utilizadas pelas suas propriedades emulsificantes e farmacológicas. O presente estudo teve como principal objetivo avaliar o uso de técnicas de extração emergentes, como Extração assistida por Ultrassom (US), Campo Elétrico Moderado (CEM) e Extração por Fluido Supercrítico (EFS) para a extração seletiva de saponinas a partir de frutos imaturos de erva mate. Foram investigadas três condições de intensidade de ultrassom (565, 423 e 282 W cm-²) e de intensidade de campo elétrico (50, 37,5 e 25 V cm-1) associadas a diferentes temperaturas de operação. A interação das intensidades de ultrassom e de campo elétrico com diferentes temperaturas foi avaliada através do método de superfície de resposta. Para as extrações por fluido super e sub crítico foram utilizadas três condições de pressão (10, 20 e 30 MPa) e posteriormente sua correlação com diferentes vazões de solvente (1,62; 2,22 e 2,78 x10-4 kg s-1) e temperatura (30, 40 e 50 °C) foi investigada através do métodos de superfície de resposta. Curvas de rendimento das extrações em função do tempo foram levantadas para as condições ótimas de campo elétrico e intensidade de ultrassom (37,5 V cm-1 e 565 W cm-², respectivamente) a 40°C. As curvas foram modeladas matematicamente, com ajuste satisfatório, por modelos cinéticos de 1ª e 2ª ordem e também por um modelo difusivo baseado na 2ª Lei de Fick. Para extração supercrítica, foi construída a curva de extração para a condição de 10 MPa e 40 °C e esta curva foi modelada matematicamente. Assim, foram estimados parâmetros relacionados à transferência de massa, importantes para a compreensão fenomenológica dos processos extrativos. Nesse estudo, a extração com CO2 supercrítico mostrou-se tecnicamente viável para a obtenção de saponinas, sendo mais seletiva em relação aos processos por campo elétrico e ultrassom. Os ensaios com ultrassom e campo elétrico conseguiram gerar extratos brutos com até 68,30 e 64,26 μgilexmg-1extrato em massa de equivalente de saponina por massa de extrato, respectivamente. Os extratos obtidos com fluido supercrítico apresentaram elevada seletividade para saponinas, gerando extratos brutos com até 100,9 μgilex mg-1 extrato de saponina por massa de extrato. A pressão de operação não apresentou efeito tanto no rendimento global de extrato quanto no de saponina. / Considering the substantial amount of saponins in unripe yerba mate fruits, they are an abundant source of raw material not exploited yet. Saponins are known as natural surfactants, being used by their emulsifier and pharmacological properties. This study aimed to evaluate emergent extraction techniques such as Ultrasound (US), Moderate Electric Field (MEF) and Supercritical Fluid Extraction (SFE) for the selective extraction of saponins from unripe fruits of yerba mate. Three power conditions (565, 423 and 282W cm-2), electric field intensities (50, 37.5 and 25 V cm-1) and pressure conditions (10, 20 and 30 MPa) were initially assayed for US, MEF and SFE respectively at 40 °C. Power and electric field intensity were found to affect the saponins yields, thus, their correlation with different temperatures were evaluated with a factorial design. At the optimal condition, US and MEF saponins yields were 6.42% and 6.83% (%gilex gextract-1). Extraction yield curves were raised for optimum conditions of electric field and ultrasound power (37.5 V cm-1 and 565 W cm-², respectively). Three different kinetic models were used to model mathematically the overall extraction curves, namely a first-order, second-order, and a mass transfer model based on Fick’s Law. The operating pressure had no effect on either the overall brute extract or saponins yield for SFE. Although the extracts obtained with supercritical fluid showed low brute extracts yields, it was highly selective for saponins yielding up to 10.09%. For supercritical extraction, the extraction curve for 10 MPa and 40 °C was assayed and the experimental data fitted by a mathematical model. Parameters related to mass transfer, important for understanding of the extractive processes, were successfully estimated. In this study, the extraction with ultrasounds, electric field and supercritical CO2 were shown to be technically viable to obtain saponins from unripe yerba mate fruits, being EFS more selective than the other technics studied.

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