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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.
1

O comportamento da lateral pósvocálica em posição de coda no falar Tocantinense: uma análise variacionista

Moura, Adriano Carlos de 22 October 2009 (has links)
Made available in DSpace on 2015-05-14T12:43:20Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 608431 bytes, checksum: 180471d1938e53bfb3a283ccaedde7d9 (MD5) Previous issue date: 2009-10-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work had as objective to analyze the process of variation of the lateral postvocalic /l/ in syllabic position of coda in the speech of Araguatins, state of Tocantins. The sample was constituted of interviews of approximately one hour of duration with 36 speakers, divided by sex, age and educational level, we correlate to these extralinguistic variables the structural variables: preceding phonological context, following phonological context, extension of word, position of the lateral and stressing. In the process of computational analysis, through the GOLDVARB, they had been selected by stepping up as relevant, in a hierarchic order, the variables: preceding phonological context, stressing, sex, extension of word, educational level, following phonological context and age. 3256 occurrences had been computed, being 2961 occurrences of the semi-vocalized lateral [w]; e 295 of deletion [Ø]. The presence of posterior vowel, in particular [u], in the Preceding phonological context did not favor, decisively, the implementation of the rule of vocalization of the post-vocalic lateral /l/. Due to the following phonological context, the vowels and the labial consonants had conditioned the deletion, in the other hand the pause was supporter to the vocalization. It was also proven that how much bigger the phonic mass bigger the propensity of the deletion of the lateral, similar situation happens when the lateral is post-tonic syllable. For social variable sex, we can say that men have favored much more the deletion of lateral in comparison with women. In the analysis of the influence of the variable educational level, it became clear that the more educated is the informant more likely occurs the maintenance of semi-vocalized variant of /l/ post-vocalic. The results for age, showed us that there is currently in Araguatins a certain stability in the use of /l/ in in syllabic position of coda in all age groups. / Este trabalho teve como objetivo analisar o processo de variação da lateral pós-vocálica /l/ em posição de coda silábica no falar de Araguatins, estado do Tocantins. A amostra foi constituída de entrevistas de aproximadamente uma hora de duração com 36 informantes, estratificados por sexo, faixa etária e escolaridade, correlacionamos a estas variáveis extralingüísticas as variáveis estruturais: contexto fonológico precedente, contexto fonológico seguinte, extensão do vocábulo, posição da lateral e tonicidade. No processo de análise computacional, através do GOLDVARB, foram selecionadas pelo stepping up como relevantes, numa ordem hierárquica, as variáveis: Contexto fonológico precedente, Tonicidade, Sexo, Extensão do Vocábulo, Escolaridade, Contexto fonológico seguinte e Faixa etária. Foram computadas 3256 ocorrências, sendo 2961 ocorrências da lateral semivocalizada [w]; e 295 de apagamento [Ø]. A presença de vogal posterior, sobretudo [u], no Contexto fonológico precedente desfavoreceu, decisivamente, a implementação da regra de vocalização da lateral pós-vocálica. Quanto ao contexto fonológico seguinte, as vogais e as consoantes labiais condicionaram ao apagamento, enquanto a pausa foi favorecedora à vocalização. Ficou comprovado também que quanto maior a massa fônica maior a propensão do apagamento da lateral, situação semelhante ao que acontece quanto a lateral se apresenta em sílaba postônica. Em relação a variável social Sexo, podemos dizer que os homens favoreceram mais o apagamento da lateral do que as mulheres. Na análise da influência da variável Anos de escolarização, ficou claro que quanto mais escolarizado for o informante mais propenso estará à manutenção da variante semivocalizada do /l/ pós-vocálico. Já os resultados para Idade, mostraram-nos que há, atualmente em Araguatins, uma certa estabilidade no uso feito da lateral em coda silábica em todas as faixas etárias.
2

Lineares Vibrationsschweißen von Kunststoffen im industriellen Umfeld

Friedrich, Sven 27 August 2014 (has links) (PDF)
Aufgrund der stetig wachsenden Anforderungen hinsichtlich Gewichtsreduzierung und Funktionsintegration, besonders im Bereich des Automobilbaus, werden traditionell aus metallischen Werkstoffen gefertigte Komponenten immer häufiger durch Kunststoffbauteile substituiert. Dem entgegen steht derzeit die Tatsache, dass, trotz hohen Prozessverständnisses und des Wissens um die Prozess-Struktur-Eigenschafts-Beziehungen beim Vibrationsschweißen, die theoretisch erzielbaren Schweißnahtfestigkeiten, von 90 % bis 100 % des unverstärkten Grundmaterials, in der industriellen Serienfertigung bei weitem nicht erreicht werden. Die Komplexität eines industriell gefertigten Bauteils wird an Plattenprüfkörpern simuliert. Die Ergebnisse der Schweißversuche zeigen, dass unterschiedliche Wandstärken im Schweißnahtbereich, Bauteilverzug und unterschiedliche Schwingrichungen innerhalb einer Schweißnaht zu ungleichmäßigen lokalen Prozessbedingungen währenden des linearen Vibrationsschweißprozesses führen. Diese hinterlassen lokale Schwachstellen, welche das Gesamtbauteilversagen bestimmen. Durch alternative Prozessführungsstrategien, wie das Hochdruckanfahren und die IR-Vorwärmung, können diese Schwachstellen reduziert und die Gesamtbauteilfestigkeit angehoben werden. Dies wird am Beispiel des Bauteilverzugs veranschaulicht. / Due to the increasing demands for weight reduction and integration of function, especially in the field of automotive, components made of metallic materials are increasingly being substituted by components made of thermoplastic materials. In contrast to this there is currently the fact that, despite the high process understanding of the vibration welding and the knowledge of the process-structure-property relationships, the theoretically achievable weld strengths of 90 % to 100 % of the unreinforced base material strength are far to be achieved in industrial series production. The complexity of an industrially manufactured component is simulated by using plate test specimens. The results of the welding experiments show that different wall thicknesses in the weld area, component warpage and different friction angle within the weld leads to nonuniform local process conditions during linear vibration welding process. This results in local weak spots, which reduce the total component strength. These local weak spots can be reduced by using alternative process strategies, such as in-process pressure variation and IR preheating. So not only the local strengths but also the total component strength will be increased. This is shown on the example of component warpage.
3

Lineares Vibrationsschweißen von Kunststoffen im industriellen Umfeld: Einflüsse und Restriktionen

Friedrich, Sven 26 June 2014 (has links)
Aufgrund der stetig wachsenden Anforderungen hinsichtlich Gewichtsreduzierung und Funktionsintegration, besonders im Bereich des Automobilbaus, werden traditionell aus metallischen Werkstoffen gefertigte Komponenten immer häufiger durch Kunststoffbauteile substituiert. Dem entgegen steht derzeit die Tatsache, dass, trotz hohen Prozessverständnisses und des Wissens um die Prozess-Struktur-Eigenschafts-Beziehungen beim Vibrationsschweißen, die theoretisch erzielbaren Schweißnahtfestigkeiten, von 90 % bis 100 % des unverstärkten Grundmaterials, in der industriellen Serienfertigung bei weitem nicht erreicht werden. Die Komplexität eines industriell gefertigten Bauteils wird an Plattenprüfkörpern simuliert. Die Ergebnisse der Schweißversuche zeigen, dass unterschiedliche Wandstärken im Schweißnahtbereich, Bauteilverzug und unterschiedliche Schwingrichungen innerhalb einer Schweißnaht zu ungleichmäßigen lokalen Prozessbedingungen währenden des linearen Vibrationsschweißprozesses führen. Diese hinterlassen lokale Schwachstellen, welche das Gesamtbauteilversagen bestimmen. Durch alternative Prozessführungsstrategien, wie das Hochdruckanfahren und die IR-Vorwärmung, können diese Schwachstellen reduziert und die Gesamtbauteilfestigkeit angehoben werden. Dies wird am Beispiel des Bauteilverzugs veranschaulicht. / Due to the increasing demands for weight reduction and integration of function, especially in the field of automotive, components made of metallic materials are increasingly being substituted by components made of thermoplastic materials. In contrast to this there is currently the fact that, despite the high process understanding of the vibration welding and the knowledge of the process-structure-property relationships, the theoretically achievable weld strengths of 90 % to 100 % of the unreinforced base material strength are far to be achieved in industrial series production. The complexity of an industrially manufactured component is simulated by using plate test specimens. The results of the welding experiments show that different wall thicknesses in the weld area, component warpage and different friction angle within the weld leads to nonuniform local process conditions during linear vibration welding process. This results in local weak spots, which reduce the total component strength. These local weak spots can be reduced by using alternative process strategies, such as in-process pressure variation and IR preheating. So not only the local strengths but also the total component strength will be increased. This is shown on the example of component warpage.

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