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Bilinguismo bimodal : um estudo sobre o acesso lexical em intérpretes de libras-portuguêsFonseca, Sandro Rodrigues January 2015 (has links)
Esta dissertação tem como objetivo geral investigar o efeito de interferência semântica no acesso lexical bilíngue bimodal em um grupo de ouvintes bilíngues bimodais adultos que atuam como TILS - tradutores e intérpretes de LIBRAS – Língua Portuguesa por meio de uma Tarefa de Reconhecimento de Tradução. Quatro objetivos específicos nortearam a pesquisa: (a) verificar o efeito de interferência semântica durante o acesso lexical bilíngue bimodal; (b) avaliar o papel da certificação de proficiência em interpretação PROLIBRAS no desempenho dos participantes na tarefa experimental; (c) avaliar o papel da experiência tradutória, considerando o número de horas de trabalho por semana, no desempenho dos participantes na Tarefa de Reconhecimento de Tradução; e (d) avaliar o papel da experiência como intérpretes de Libras, considerando o número de anos de experiência de trabalho, na Tarefa de Reconhecimento de Tradução. Para a realização da pesquisa foram utilizados dois instrumentos, um Questionário de Histórico da Linguagem e Autoavaliação da Proficiência, e um Teste de Reconhecimento de Tradução desenvolvido especificamente para este estudo, no qual os participantes foram solicitados a observar sequências de sinais em um vídeo seguido de uma palavra em Língua Portuguesa e a responder se a palavra correspondia à tradução correta do sinal. A palavra em Língua Portuguesa poderia se enquadrar em uma das seguintes condições experimentais: tradução correta, tradução incorreta semanticamente relacionada, tradução incorreta semanticamente não relacionada. As hipóteses previam que (a) os participantes seriam mais rápidos em identificar itens na condição de tradução correta do que nas duas outras condições; (b) os intérpretes demonstrariam um menor percentual de erros ao identificar itens na condição de tradução correta do que nas duas outras condições, exibindo percentual de erros ainda maior na condição de tradução incorreta semanticamente relacionada; (c) os participantes que declarassem possuir o certificado de proficiência em interpretação PROLIBRAS teriam um desempenho mais rápido e menor percentual de erros na tarefa; (d) os intérpretes que declarassem atuar mais horas por semana teriam um desempenho mais rápido e menor percentual de erros; por fim, (e) que os participantes que declarassem ter mais anos de experiência seriam mais rápidos e obteriam um menor percentual de erros na tarefa. Os resultados confirmam o efeito de interferência semântica em bilíngues bimodais, embora a análise do papel da experiência linguística tenha revelado que não houve diferença de resultados entre os que possuem a certificação PROLIBRAS e os que não a possuem, sendo que o mesmo foi constatado entre os que trabalham mais ou menos anos como intérpretes. A análise dos resultados da experiência em termos de horas por semana, no entanto, revelou que a comparação entre o grupo que trabalha vinte horas com o que trabalha quarenta horas indicou que os que trabalham menos horas responderam mais rapidamente aos itens de todas as condições de tradução da tarefa. Os resultados são interpretados com base em teorias sobre a representação do conhecimento linguístico, do acesso lexical e da interferência semântica, e sugerem a presença do efeito de interferência semântica nos bilíngues testados. Além disso, a ausência de um efeito da certificação PROLIBRAS na tarefa é analisada como uma indicação da necessidade de se investigar mais profundamente formas alternativas de avaliar a experiência dos intérpretes. / This dissertation has as its general objective to study the semantic interference effect in bimodal bilingual lexical access in a group of hearing adults bimodal bilinguals who work as sign language interpreter LIBRAS – Portuguese through a Translation Recognition Task. Four specific objectives guided this research: (a) to verify the semantic interference effect during bilingual bimodal lexical access; (b) to assess the role of the PROLIBRAS interpreting proficiency certification on the performance of the participants during the experimental task; (c) to assess the role of the translation experience, considering the number of hours of work per week, on the performance of the participants during the Translation Recognition Task; and (d) to assess the role of the experience as interpreters, considering the number of years of work experience, seen through the Translation Recognition Task. In order to accomplish such goals two instruments were used: a Self-Proficiency and Language History Questionnaire and a Translation Recognition Task developed for this study, in which participants were asked to observe sequences of signs in video followed by a word in Portuguese and answer whether the word corresponded as the correct translation of the sign. The word in Portuguese could fit in one of the following experimental conditions: correct translation, semantic related incorrect translation, not semantic related incorrect translation. The hypotheses were that (a) the participants would be faster at identifying items on the correct translation condition than the other two conditions; (b) interpreters would have a smaller error rate at identifying items on the correct translation condition than the other two conditions, showing even more error rate on the semantic related incorrect translation condition; (c) the participants that would declare to own a LIBRAS proficiency certificate would show a faster performance and smaller error rate; and finally, (e) that participants that would declared to have more year of experience as interpreters would be faster and would have a smaller error rate on the task. The results confirmed the semantic interference effect in bimodal bilinguals, although the analyses of the role of the language experience showed no difference of results among those who own a PROLIBRAS certificate and those who do not. The same was seen among those work more or less years as interpreters. The analyses of the results of the experience in terms of hours per week, however, showed that the comparison between the group who work twenty hours with the group who work forty hours indicated that the ones who work fewer hours answered faster to the items in all the task conditions. The results are interpreted using as base the theories about language knowledge representation, lexical access and semantic interference. Besides, the lack of effect on the PROLIBRAS certificate on the task is analyzed as an indication of the need to study deeply alternative ways to assess the experience of the interpreters.
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Optimization of Particle Size of α-Alumina Separator on Performance of Lithium Ion BatteriesJanuary 2017 (has links)
abstract: Lithium ion batteries prepared with a ceramic separator, have proven to possess improved safety, reliability as well as performance characteristics when compared to those with polymer separators which are prone to thermal runaway. Purely inorganic separators are highly brittle and expensive. The electrode-supported ceramic separator permits thinner separators which are a lot more flexible in comparison. In this work, it was observed that not any α-alumina could be used by the blade coating process to get a good quality separator on Li4Ti5O12 (LTO) electrode. In this work specifically, the effect of particle size of α-alumina, on processability of slurry was investigated. The effect of the particle size variations on quality of separator formation was also studied. Most importantly, the effect of alumina particle size and its distribution on the performance of LTO/Li half cells is examined in detail. Large-sized particles were found to severely limit the ability to fabricate such separators. The α-alumina slurry was coated onto electrode substrate, leading to possible interaction between α-alumina and LTO substrate. The interaction between submicron sized particles of α-alumina with the substrate electrode pores, was found to affect the performance and the stability of the separator. Utilizing a bimodal distribution of submicron sized particles with micron sized particles of α-alumina to prepare the separator, improved cell performance was observed. Yet only a specific ratio of bimodal distribution achieved good results both in terms of separator formation and resulting cell performance. The interaction of α-alumina and binder in the separator, and its effect on the performance of substrate electrode was investigated, to understand the need for bimodal distribution of powder forming the separator. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2017
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Bilinguismo bimodal : um estudo sobre o acesso lexical em intérpretes de libras-portuguêsFonseca, Sandro Rodrigues January 2015 (has links)
Esta dissertação tem como objetivo geral investigar o efeito de interferência semântica no acesso lexical bilíngue bimodal em um grupo de ouvintes bilíngues bimodais adultos que atuam como TILS - tradutores e intérpretes de LIBRAS – Língua Portuguesa por meio de uma Tarefa de Reconhecimento de Tradução. Quatro objetivos específicos nortearam a pesquisa: (a) verificar o efeito de interferência semântica durante o acesso lexical bilíngue bimodal; (b) avaliar o papel da certificação de proficiência em interpretação PROLIBRAS no desempenho dos participantes na tarefa experimental; (c) avaliar o papel da experiência tradutória, considerando o número de horas de trabalho por semana, no desempenho dos participantes na Tarefa de Reconhecimento de Tradução; e (d) avaliar o papel da experiência como intérpretes de Libras, considerando o número de anos de experiência de trabalho, na Tarefa de Reconhecimento de Tradução. Para a realização da pesquisa foram utilizados dois instrumentos, um Questionário de Histórico da Linguagem e Autoavaliação da Proficiência, e um Teste de Reconhecimento de Tradução desenvolvido especificamente para este estudo, no qual os participantes foram solicitados a observar sequências de sinais em um vídeo seguido de uma palavra em Língua Portuguesa e a responder se a palavra correspondia à tradução correta do sinal. A palavra em Língua Portuguesa poderia se enquadrar em uma das seguintes condições experimentais: tradução correta, tradução incorreta semanticamente relacionada, tradução incorreta semanticamente não relacionada. As hipóteses previam que (a) os participantes seriam mais rápidos em identificar itens na condição de tradução correta do que nas duas outras condições; (b) os intérpretes demonstrariam um menor percentual de erros ao identificar itens na condição de tradução correta do que nas duas outras condições, exibindo percentual de erros ainda maior na condição de tradução incorreta semanticamente relacionada; (c) os participantes que declarassem possuir o certificado de proficiência em interpretação PROLIBRAS teriam um desempenho mais rápido e menor percentual de erros na tarefa; (d) os intérpretes que declarassem atuar mais horas por semana teriam um desempenho mais rápido e menor percentual de erros; por fim, (e) que os participantes que declarassem ter mais anos de experiência seriam mais rápidos e obteriam um menor percentual de erros na tarefa. Os resultados confirmam o efeito de interferência semântica em bilíngues bimodais, embora a análise do papel da experiência linguística tenha revelado que não houve diferença de resultados entre os que possuem a certificação PROLIBRAS e os que não a possuem, sendo que o mesmo foi constatado entre os que trabalham mais ou menos anos como intérpretes. A análise dos resultados da experiência em termos de horas por semana, no entanto, revelou que a comparação entre o grupo que trabalha vinte horas com o que trabalha quarenta horas indicou que os que trabalham menos horas responderam mais rapidamente aos itens de todas as condições de tradução da tarefa. Os resultados são interpretados com base em teorias sobre a representação do conhecimento linguístico, do acesso lexical e da interferência semântica, e sugerem a presença do efeito de interferência semântica nos bilíngues testados. Além disso, a ausência de um efeito da certificação PROLIBRAS na tarefa é analisada como uma indicação da necessidade de se investigar mais profundamente formas alternativas de avaliar a experiência dos intérpretes. / This dissertation has as its general objective to study the semantic interference effect in bimodal bilingual lexical access in a group of hearing adults bimodal bilinguals who work as sign language interpreter LIBRAS – Portuguese through a Translation Recognition Task. Four specific objectives guided this research: (a) to verify the semantic interference effect during bilingual bimodal lexical access; (b) to assess the role of the PROLIBRAS interpreting proficiency certification on the performance of the participants during the experimental task; (c) to assess the role of the translation experience, considering the number of hours of work per week, on the performance of the participants during the Translation Recognition Task; and (d) to assess the role of the experience as interpreters, considering the number of years of work experience, seen through the Translation Recognition Task. In order to accomplish such goals two instruments were used: a Self-Proficiency and Language History Questionnaire and a Translation Recognition Task developed for this study, in which participants were asked to observe sequences of signs in video followed by a word in Portuguese and answer whether the word corresponded as the correct translation of the sign. The word in Portuguese could fit in one of the following experimental conditions: correct translation, semantic related incorrect translation, not semantic related incorrect translation. The hypotheses were that (a) the participants would be faster at identifying items on the correct translation condition than the other two conditions; (b) interpreters would have a smaller error rate at identifying items on the correct translation condition than the other two conditions, showing even more error rate on the semantic related incorrect translation condition; (c) the participants that would declare to own a LIBRAS proficiency certificate would show a faster performance and smaller error rate; and finally, (e) that participants that would declared to have more year of experience as interpreters would be faster and would have a smaller error rate on the task. The results confirmed the semantic interference effect in bimodal bilinguals, although the analyses of the role of the language experience showed no difference of results among those who own a PROLIBRAS certificate and those who do not. The same was seen among those work more or less years as interpreters. The analyses of the results of the experience in terms of hours per week, however, showed that the comparison between the group who work twenty hours with the group who work forty hours indicated that the ones who work fewer hours answered faster to the items in all the task conditions. The results are interpreted using as base the theories about language knowledge representation, lexical access and semantic interference. Besides, the lack of effect on the PROLIBRAS certificate on the task is analyzed as an indication of the need to study deeply alternative ways to assess the experience of the interpreters.
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Bilinguismo bimodal : um estudo sobre o acesso lexical em intérpretes de libras-portuguêsFonseca, Sandro Rodrigues January 2015 (has links)
Esta dissertação tem como objetivo geral investigar o efeito de interferência semântica no acesso lexical bilíngue bimodal em um grupo de ouvintes bilíngues bimodais adultos que atuam como TILS - tradutores e intérpretes de LIBRAS – Língua Portuguesa por meio de uma Tarefa de Reconhecimento de Tradução. Quatro objetivos específicos nortearam a pesquisa: (a) verificar o efeito de interferência semântica durante o acesso lexical bilíngue bimodal; (b) avaliar o papel da certificação de proficiência em interpretação PROLIBRAS no desempenho dos participantes na tarefa experimental; (c) avaliar o papel da experiência tradutória, considerando o número de horas de trabalho por semana, no desempenho dos participantes na Tarefa de Reconhecimento de Tradução; e (d) avaliar o papel da experiência como intérpretes de Libras, considerando o número de anos de experiência de trabalho, na Tarefa de Reconhecimento de Tradução. Para a realização da pesquisa foram utilizados dois instrumentos, um Questionário de Histórico da Linguagem e Autoavaliação da Proficiência, e um Teste de Reconhecimento de Tradução desenvolvido especificamente para este estudo, no qual os participantes foram solicitados a observar sequências de sinais em um vídeo seguido de uma palavra em Língua Portuguesa e a responder se a palavra correspondia à tradução correta do sinal. A palavra em Língua Portuguesa poderia se enquadrar em uma das seguintes condições experimentais: tradução correta, tradução incorreta semanticamente relacionada, tradução incorreta semanticamente não relacionada. As hipóteses previam que (a) os participantes seriam mais rápidos em identificar itens na condição de tradução correta do que nas duas outras condições; (b) os intérpretes demonstrariam um menor percentual de erros ao identificar itens na condição de tradução correta do que nas duas outras condições, exibindo percentual de erros ainda maior na condição de tradução incorreta semanticamente relacionada; (c) os participantes que declarassem possuir o certificado de proficiência em interpretação PROLIBRAS teriam um desempenho mais rápido e menor percentual de erros na tarefa; (d) os intérpretes que declarassem atuar mais horas por semana teriam um desempenho mais rápido e menor percentual de erros; por fim, (e) que os participantes que declarassem ter mais anos de experiência seriam mais rápidos e obteriam um menor percentual de erros na tarefa. Os resultados confirmam o efeito de interferência semântica em bilíngues bimodais, embora a análise do papel da experiência linguística tenha revelado que não houve diferença de resultados entre os que possuem a certificação PROLIBRAS e os que não a possuem, sendo que o mesmo foi constatado entre os que trabalham mais ou menos anos como intérpretes. A análise dos resultados da experiência em termos de horas por semana, no entanto, revelou que a comparação entre o grupo que trabalha vinte horas com o que trabalha quarenta horas indicou que os que trabalham menos horas responderam mais rapidamente aos itens de todas as condições de tradução da tarefa. Os resultados são interpretados com base em teorias sobre a representação do conhecimento linguístico, do acesso lexical e da interferência semântica, e sugerem a presença do efeito de interferência semântica nos bilíngues testados. Além disso, a ausência de um efeito da certificação PROLIBRAS na tarefa é analisada como uma indicação da necessidade de se investigar mais profundamente formas alternativas de avaliar a experiência dos intérpretes. / This dissertation has as its general objective to study the semantic interference effect in bimodal bilingual lexical access in a group of hearing adults bimodal bilinguals who work as sign language interpreter LIBRAS – Portuguese through a Translation Recognition Task. Four specific objectives guided this research: (a) to verify the semantic interference effect during bilingual bimodal lexical access; (b) to assess the role of the PROLIBRAS interpreting proficiency certification on the performance of the participants during the experimental task; (c) to assess the role of the translation experience, considering the number of hours of work per week, on the performance of the participants during the Translation Recognition Task; and (d) to assess the role of the experience as interpreters, considering the number of years of work experience, seen through the Translation Recognition Task. In order to accomplish such goals two instruments were used: a Self-Proficiency and Language History Questionnaire and a Translation Recognition Task developed for this study, in which participants were asked to observe sequences of signs in video followed by a word in Portuguese and answer whether the word corresponded as the correct translation of the sign. The word in Portuguese could fit in one of the following experimental conditions: correct translation, semantic related incorrect translation, not semantic related incorrect translation. The hypotheses were that (a) the participants would be faster at identifying items on the correct translation condition than the other two conditions; (b) interpreters would have a smaller error rate at identifying items on the correct translation condition than the other two conditions, showing even more error rate on the semantic related incorrect translation condition; (c) the participants that would declare to own a LIBRAS proficiency certificate would show a faster performance and smaller error rate; and finally, (e) that participants that would declared to have more year of experience as interpreters would be faster and would have a smaller error rate on the task. The results confirmed the semantic interference effect in bimodal bilinguals, although the analyses of the role of the language experience showed no difference of results among those who own a PROLIBRAS certificate and those who do not. The same was seen among those work more or less years as interpreters. The analyses of the results of the experience in terms of hours per week, however, showed that the comparison between the group who work twenty hours with the group who work forty hours indicated that the ones who work fewer hours answered faster to the items in all the task conditions. The results are interpreted using as base the theories about language knowledge representation, lexical access and semantic interference. Besides, the lack of effect on the PROLIBRAS certificate on the task is analyzed as an indication of the need to study deeply alternative ways to assess the experience of the interpreters.
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Two languages, two modalities:a special type of early bilingual language acquisition in hearing children of Deaf parentsKanto, L. (Laura) 17 May 2016 (has links)
Abstract
In this study, early bilingual language acquisition was explored from the age of 12 to 36 months in 10 hearing children of Deaf parents, KODAs (Kids of Deaf Adults). KODA children’s language acquisition is bimodal; they acquire simultaneously sign language in visual-gestural and spoken language in auditory-vocal modality. This study aimed to describe the developmental paths of early bilingual language acquisition and their interrelationships with language input. Additionally, the characteristics of children’s language use and their associations with the features of the linguistic environment, child’s language competence and contextual variables were examined.
Information about the children’s linguistic environment was collected with parental interviews. Children’s linguistic development (productive vocabulary) was measured with the MacArthur Communicative Development Inventory (MCDI) in both Finnish Sign Language (FinSL) and the Finnish language between the ages of 12 to 30 months. Children’s development in the Finnish language was tested at the age of 36 months by using the Reynell Developmental Language Scales III. Additionally, the children’s interaction was video recorded twice a year between the ages of 12 to 36 months during three different play sessions: with their Deaf parent, with the Deaf parent and a hearing adult and with the hearing adult alone.
A large variation was uncovered in both the amount and type of language input and the children’s bilingual developmental paths. According to the results of the MCDI, KODA children’s (N = 8) mean size of productive vocabulary in both languages separately was smaller when compared to the monolingual norms. However, in all but three children, their total vocabulary, which includes both productive vocabulary of FinSL and Finnish, was comparable with age peers. According to the Reynell test in Finnish, three children scored at age level, three within –1 SD and two children within –2 SD.
Contextual variables clearly influenced the KODA children’s language use. KODA children, as young as 12 months old, accommodated their use of language and communication modes according to the language(s) of their interlocutor(s). Children preferred to code-mix when communicating with their Deaf parent by producing simultaneous, mainly semantically congruent signs and words. / Tiivistelmä
Tässä tutkimuksessa selvitettiin 10 KODA:n (Engl. Kids of Deaf Adults) eli kuuron vanhemman kuulevan lapsen varhaista kaksikielisyyden kehitystä ikävälillä 12 ja 36 kuukautta. KODA-lapset omaksuvat simultaanisesti kaksi modaliteetiltaan erilaista kieltä, viittomakielen ja puhutun kielen. Näin heidän kaksikielisyytensä perustuu kahden aistikanavan käyttöön. Tutkimuksen tavoitteena oli kuvata KODA-lasten varhaista kaksikielisyyden kehitystä sekä tarkastella kehitykseen yhteydessä olevia tekijöitä lasten kieliympäristössä. Lisäksi tavoitteena oli eritellä lasten kielten tuoton piirteitä ja tarkastella, miten kieliympäristöön, kielitaitoon ja eri kielenkäyttökonteksteihin liittyvät tekijät ovat niihin yhteydessä.
Lasten kieliympäristön piirteistä kerättiin tietoa vanhempien haastattelujen avulla. KODA-lasten kielten kehitystä arvioitiin MCDI-lomakkeen (MacArthur Communicative Development Inventory) avulla ikävälillä 12 ja 30 kuukautta. Lisäksi suomen kielen taitoja arvioitiin Reynellin kielellisen kehityksen testillä silloin, kun lapset olivat 36 kuukauden ikäisiä. Videoaineisto kerättiin puolivuosittain videoimalla lasta aina kolmessa eri leikkitilanteessa: ensin kuuron vanhemman kanssa, sitten kuuron vanhemman ja kuulevan aikuisen kanssa ja lopuksi kuulevan kanssa.
Sekä lasten kieliympäristön piirteissä että kaksikielisyyden kehityksessä oli laajaa yksilöllistä vaihtelua. MCDI:n tulokset osoittivat, että KODA lasten (N = 8) ryhmän leksikon koko jäi molemmissa kielissä ainoastaan suomen kieltä omaksuvien lasten normituloksia alhaisemmaksi, mutta tuottavan kokonaisleksikon suuruus (tuotettujen sanojen ja viittomien summa) silti vastasi suomen kieltä omaksuvien lasten normituloksia. Yksilöllinen vaihtelu tuloksissa oli kuitenkin suurta. Reynellin testin mukaan kolme lasta suoriutui testistä ikätason mukaisesti, kolmen lapsen suoritus oli yhden keskihajonnan ja kahden lapsen suoritus kahden keskihajonnan verran ikätasoa alhaisempi.
Vuorovaikutuskumppani vaikutti KODA-lasten kielten käytön piirteisiin tilastollisesti merkitsevällä tasolla. KODA-lapset pystyivät jo 12 kuukauden iässä muuttamaan käyttämäänsä kieltä ja kommunikointimuotoa vuorovaikutuskumppanin mukaan. Lisäksi he yhdistivät kielten koodeja erityisesti kommunikoidessaan kuuron vanhemman kanssa tuottamalla useimmiten semanttiselta sisällöltään vastaavan viittoman ja sanan samanaikaisesti.
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Biofoams and Biocomposites based on Wheat Gluten ProteinsWu, Qiong January 2017 (has links)
Novel uses of wheat gluten (WG) proteins, obtained e.g. as a coproduct from bio-ethanol production, are presented in this thesis. A flame-retardant foam was prepared via in-situ polymerization of hydrolyzed tetraethyl orthosilicate (TEOS) in a denatured WG matrix (Paper I). The TEOS formed a well-dispersed silica phase in the walls of the foam. With silica contents ≥ 6.7 wt%, the foams showed excellent fire resistance. An aspect of the bio-based foams was their high sensitivity to fungi and bacterial growth. This was addressed in Paper II using a natural antimicrobial agent Lanasol. In the same paper, a swelling of 32 times its initial weight in water was observed for the pristine WG foam and both capillary effects and cell wall absorption contributed to the high uptake. In Paper III, conductive and flexible foams were obtained using carbon-based nanofillers and plasticizer. It was found that the electrical resistance of the carbon nanotubes and carbon black filled foams were strain-independent, which makes them suitable for applications in electromagnetic shielding (EMI) and electrostatic discharge protection (ESD). Paper IV describes a ‘water-welding’ method where larger pieces of WG foams were made by wetting the sides of the smaller cubes before being assembled together. The flexural strength of welded foams was ca. 7 times higher than that of the same size WG foam prepared in one piece. The technique provides a strategy for using freeze-dried WG foams in applications where larger foams are required. Despite the versatile functionalities of the WG-based materials, the mechanical properties are often limited due to the brittleness of the dry solid WG. WG/flax composites were developed for improved mechanical properties of WG (Paper V). The results revealed that WG, reinforced with 19 wt% flax fibres, had a strength that was ca. 8 times higher than that of the pure WG matrix. Furthermore, the crack-resistance was also significantly improved in the presence of the flax. / <p>QC 20170524</p>
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Attention capture by sudden and unexpected changes : a multisensory perspectiveMarsja, Erik January 2017 (has links)
The main focus for this thesis was cross-modal attention capture by sudden and unexpected sounds and vibrations, known as deviants, presented in a stream the same to-be-ignored stimulus. More specifically, the thesis takes a multisensory perspective and examines the possible similarities and differences in how deviant vibrations and sounds affect visual task performance (Study I), and whether the deviant and standard stimuli have to be presented within the same modality to capture attention away from visual tasks (Study II). Furthermore, by presenting spatial deviants (changing the source of the stimuli from one side of the body to the other) in audiotactile (bimodal), tactile, and auditory to-be-ignored, it explores whether bimodal stimuli are more salient compared to unimodal (Study III). In addition, Study III tested the claims that short-term memory is domain-specific. In line with previous research, Study I found that both auditory and tactile deviants captured attention away from the visual task. However, the temporal dynamics between the two modalities seem to differ. That is, it seems like practice causes the effect of vibratory deviants to reduce, whereas this is not the case for auditory deviants. This suggests that there are central mechanisms (detection of the change) and sensory-specific mechanisms. Study II found that the deviant and standard stimuli must be presented within the same modality. If attention capture by deviants is produced by a mismatch within a neural model predicting upcoming stimuli, the neural model is likely built on stimuli within each modality separately. The results of Study III revealed that spatial and verbal short-term memory are negatively affected by a spatial change in to-be-ignored sequences, but only when the change is within a bimodal sequence. These results can be taken as evidence for a unitary account of short-term memory (verbal and spatial information stored in the same storage) and that bimodal stimuli may be integrated into a unitary percept that make any change in the stream more salient.
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Peripersonal space : a multisensory interface for body-objects interactions / L’espace péripersonnel : une interface ultisensorielle pour les interactions entre le corps et les objetsBrozzoli, Claudio 20 November 2009 (has links)
Notre habilité à interagir avec les objets du monde nécessite l’intégration d’informations provenant de différents canaux sensoriels, dans le cadre de la construction d’une représentation de l’espace en particulier des informations visuelles et tactiles. L’espace péri personnel et l’intégration visuo-tactile ont été l’objet d’importantes recherche récemment. Des études neuro physiologiques chez le primate non-humain ont montré l’existence de neurones bi modaux activés à la fois par des stimulations tactiles et par des stimulations visuelles si ces dernières étaient présentées près d’une partie du corps (par exemple la main). Il a été proposé que ces neurones bi-modaux constituent le substrat neuronal de la représentation de l’espace péri personnel. Les études neuropsychologiques menées chez des patients présentant une extinction cross-modale consécutive à une lésion pariétale droite ont permis de suggérer l’existence du même type de représentation de l’espace péri personnel chez l’homme. Les données issues des études en neuro imagerie fonctionnelle sont venues par la suite conforter cette idée. Plus récemment, à travers l’utilisation d’outils, des données acquises chez le primate humain et non humain ont révélé les propriétés dynamiques de cette représentation spatiale. Selon notre hypothèse la représentation de l’espace péri personnel est une interface présidant aux interactions du corps avec les objets du monde externe. Nous avons donc évalué le rôle et l’état de l’espace péri personnel lors de l’exécution de mouvements volontaires vers des objets (comme une simple saisie) et lors de mouvements involontaires d’évitement. Lors d’une première série d’expériences nous avons étudié les coordonnées spatiales du codage des objets qui soudainement se rapprochent du corps grâce à la mesure des potentiels évoqués moteurs. Cette étude a révélé que l’espace péri personnel joue un rôle dans la représentation des objets approchant le corps et dans la sélection des mouvements appropriés en réponse. Lors d’une seconde série d’expériences nous avons utilisé un paradigme d’interférence visuo-tactile couplé à l’enregistrement cinématique des mouvements de saisie afin d’examiner la représentation de l’espace péri personnel lors de 1 l’exécution d’actions volontaires. Cette approche novatrice nous a permis de mettre en évidence que l’action volontaire induit un recodage en ligne de l’interaction visuo-tactile dans l’espace de préhension. Ce recodage de l’action s’effectue en coordonnées centrées sur la partie du corps qui exécute l’action. En conclusion nos études expérimentales démontrent que l’espace péri personnel est une interface multi sensorielle qui a été sélectionnée à travers l’évolution non seulement pour la gestion des mouvements d’évitement et de défense mais également pour l’exécution d’actions volontaires. / Our ability to interact with the environment requires the integration of multisensory information for the construction of spatial representations. The peripersonal space (i.e., the sector of space closely surrounding one’s body) and the integrative processes between visual and tactile inputs originating from this sector of space have been at the center of recent years investigations. Neurophysiological studies provided evidence for the presence in the monkey brain of bimodal neurons, which are activated by tactile as well as visual information delivered near to a specific body part (e.g., the hand). Neuropsychological studies on right brain-damaged patients who present extinction and functional neuroimaging findings suggest the presence of similar bimodal systems in the human brain. Studies on the effects of tool-use on visual-tactile interaction revealed similar dynamic properties of the peripersonal space in monkeys and humans. The functional role of the multisensory coding of peripersonal space is, in our hypothesis, that of providing the brain with a sensori-motor interface for body-objects interactions. Thus, not only it could be involved in driving involuntary defensive movements in response to objects approaching the body, but could be also dynamically maintained and updated as a function of manual voluntary actions performed towards objects in the reaching space. We tested the hypothesis of an involvement of peripersonal space in executing both voluntary and defensive actions. To these aims, we joined a well known cross-modal congruency effect between visual and tactile information to a kinematic approach to demonstrate that voluntary grasping actions induce an on-line re-weighting of multisensory interactions in the peripersonal space. We additionally show that this modulation is handcentred. We also used a motor evoked potentials approach to investigate which coordinates system is used to code the peripersonal space during motor preparation if real objects rapidly approach the body. Our findings provide direct evidence for automatic hand-centred coding of visual space and suggest that peripersonal space may also serve to represent rapidly 3 approaching and potentially noxious objects, thus enabling the rapid selection of appropriate motor responses. These results clearly show that peripersonal space is a multisensori-motor interface that might have been selected through evolution for optimising the interactions between the body and the objects in the external world.
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Sturcture of Three-Dimensional Separated Flow on Symmetric BumpsByun, Gwibo 14 November 2005 (has links)
Surface mean pressures, oil flow visualization, and 3-velocity-component laser-Doppler velocimeter measurements are presented for a turbulent boundary layer of momentum thickness Reynolds number, 7300 and thickness delta over two circular based axisymmetric bumps of height H = delta and 2delta and one rectangular based symmetric bump of H = 2delta. LDV data were obtained at one plane x/H ¥ 3.26 for each case. Complex vortical separations occur on the leeside and merge into large stream-wise mean vortices downstream for the 2 axisymmetric cases. The near-wall flow (y+ < 90) is dominated by the wall. For the axisymmetric cases, the vortices in the outer region produce large turbulence levels near the centerline and appear to have low frequency motions that contribute to turbulent diffusion. For the case with a narrower span-wise shape, there are sharper separation lines and lower turbulence intensities in the vortical downstream flow.
Fine-spatial-resolution LDV measurements were also obtained on half of the leeside of an axisymmetric bump (H/delta = 2) in a turbulent boundary layer. Three-dimensional (3-D) separations occur on the leeside with one saddle separation on the centerline that is connected by a separation line to one focus separation on each side of the centerline. Downstream of the saddle point the mean backflow converges to the focal separation points in a thin region confined within about 0.15delta from the local bump surface. The mean backflow zone is supplied by the intermittent large eddies as well as by the near surface flow from the side of the bump. The separated flow has a higher turbulent kinetic energy and shows bimodal histograms in local and U and W, which appear to be due to highly unsteady turbulent motions. By the mode-averaged analysis of bimodal histograms, highly unsteady flow structures are estimated and unsteady 3-D separations seem to be occurring over a wide region on the bump leeside. The process of these separations has very complex dynamics having a large intermittent attached and detached flow region which is varying in time. These bimodal features with highly correlated local u and w fluctuating motions are the major source of large Reynolds stresses local u2, w2 and -uw. Because of the variation of the mean flow angle in the separation zones, the turbulent flow from different directions is non-correlated, resulting in lower shearing stresses. Farther from the wall, large stream-wise vortices form from flow around the sides of the bump. / Ph. D.
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Mechanismen der bimodalen Membran-PR3-Expression auf neutrophilen GranulozytenEulenberg, Claudia 07 November 2013 (has links)
Anti-Neutrophile Cytoplasmatische Antikörper verursachen nekrotisierende Vaskulitiden kleiner Blutgefäße. Die Serinprotease PR3 ist ein ANCA-Zielantigen, welches von zirkulierenden ANCA auf der Zellmembran erkannt wird. ANCA aktivieren neutrophile Granulozyten, die dann die nekrotisierende Vaskulitis verursachen. Das Membran-PR3 Expressionsmuster ist bimodal wobei mPR3-niedrig- und mPR3-hoch-exprimierende Zellen existieren. Wir testeten die Hypothese, dass ein Membranrezeptor eine hohe mPR3-Expression vermittelt. Wir verwendeten humane neutrophile Granulozyten, neutrophil-differenzierte Stammzellen und transfizierte HEK293 Zellen. Wir identifizierten das Glykoprotein CD177 als einen mPR3-präsentierenden Rezeptor. CD177 zeigte eine spezifische Bindung von reifem PR3-Protein, nicht aber von einem unprozessierten PR3. Wir separierten die mPR3-Zellpopulationen und führten Durchflusszytometrie, Giemsa-Färbung, Western Blot-Experimente und RT-PCR für die PR3 und CD177 mRNA-Expression durch. Wir fanden, dass die mPR3hoch neutrophilen Granulozyten PR3- und CD177-Protein enthielten, während in den mPR3niedrig neutrophilen Granulozyten nur PR3, aber kein CD177 detektierbar war. Die CD177-Regulation vollzog sich auf transkriptioneller Ebene, da die Zellen, die negativ für das CD177-Protein waren auch keine mRNA transkribierten. Um die Grundlage der fehlenden CD177-Transkription zu analysieren, identifizierten wir den Transkriptionsstart von CD177 für eine anschließende Mutations- und SNP-Analyse. Die CD177-Sequenzen der proteinkodierenden Regionen und der Intron-Exon-Übergänge der beiden Zellpopulationen waren identisch. Jedoch fanden wir, dass das CD177-Gen einer monoallelischen Expression unterliegt. Es wurde dabei maternale als auch paternale monoallelische Expression detektiert. In weiterführenden Untersuchungen soll der Regulationsmechanismus der monoallelischen CD177-Expression charakterisiert werden. / Anti-Neutrophil Cytoplasmic Antibodies cause necrotizing small-vessel vasculitis. The serine protease PR3 provides a main ANCA target antigen and is recognized by circulating ANCA on the neutrophil cell surface. ANCA activate neutrophils and activated neutrophils cause vasculitis. The membrane-PR3 expression pattern is bimodal in that low and high mPR3 expressing cells can be distinguished. We tested the hypothesis that a membrane receptor mediates mPR3high expression. We studied human neutrophils, neutrophilic differentiated CD34-positive hematopoietic stem cells and transfected HEK293 cells. We identified the glycoprotein CD177 as an mPR3 presenting receptor. CD177 demonstrated specific binding of mature, but not of unprocessed pro-PR3. We separated the two mPR3 populations and performed cytometry analysis, Giemsa staining, western blot analysis and RT-PCR for PR3 and CD177 expression. We detected PR3 and CD177 protein in mPR3high expressing neutrophils, whereas only PR3, but no CD177 was found in mPR3low expressing cells. Regulation took place on a transcriptional level because cells that were negative for CD177 protein were also negative for mRNA. To further study this finding, we identified the CD177 transcription start for a subsequent mutation and SNP analysis. CD177 sequences of the protein-coding regions and the intron-exon regions did not differ in both populations. However, we found a monoallelic CD177 expression and were able to detect maternal as well as paternal allele expression. Future experiments will elucidate the mechanisms that control monoallelic CD177 gene expression.
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