Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 281-300).

Thesis (doctoral)--Universität, Köln, 2000. / Includes bibliographical references (p. 245-259).

L'augmentation des dimensions des éoliennes est nécessaire pour réduire le coût du rendement énergétique des parcs éoliens. L'optimisation de ces structures est liée aux renforts fibreux qu'elles utilisent. La rigidité des pâles d'éoliennes provient des longerons en composites monolithiques mis en forme à partir de renforts NCF (« Non-Crimp Fabrics ») unidirectionnels et de résine thermodurcissable. Les renforts se présentent sous forme d'empilement de deux couches (0° et+/- 80°) cousues dans l'épaisseur par un fil polyester. La structure fibreuse, contrôlée par les paramètres de conception, influence les liens de causes à effets entre les paramètres de conception et les performances du renfort et du composite. Il est donc nécessaire d'optimiser les composites pour leur application. Trois paramètres de conception sont étudiés pour établir ces liens : la longueur de couture, le dessin de couture et la masse linéique de la trame. Ces liens sont dévoilés par la mise en relation de données morphologiques issues d'analyse d'images du renfort sec et du composite avec les propriétés macroscopiques déterminées par le biais de moyens expérimentaux. Ces derniers permettent notamment de déterminer le tenseur de perméabilité hydraulique des renforts ainsi que les propriétés élastiques des composites. Il apparait que chacun des paramètres étudiés influence l'hétérogénéité des composites. Cette caractéristique est favorable pour le procédé d'infusion mais affecte la tenue en fatigue des longerons. L'optimisation des renforts NCF pour leur application requiert donc d'établir un compromis. Une autre solution consisterait à permettre une évolution de la morphologie du composite lors de la mise en forme, pour passer d'un renfort sec hétérogène à un composite homogène en terme de fraction volumique de fibre. / The energetic pricing of windmills involves the production cost of wind turbines and theirlifespan. Increasing the performances of these structures comes with an increase of the bladesdimensions. The spar caps of the latters, providing the strength to the blades, are made ofunidirectional glass fiber reinforcement known as NCF (Non-Crimp Fabrics). They involve two layers ofspecific orientations (0° and +/- 80°) stitched together. The architecture formed by the reinforcement isdependent on the design parameters which control the performance, on the fabric during the infusionprocess, and on the composite in the final structure. Therefore, the optimization of the NCF for thewindmill application is controlled by the design parameters. Three parameters (the stitch length, thestitch pattern and the weft Tex) are studied in order to establish the links morphology / process andmorphology / mechanical performances. Experimental investigations are undertaken to determine boththe hydraulic permeability tensor of the fabrics and the elastic properties of their composite. Thesemacroscopic properties are related to the morphology determined using images analysis technics. It isdemonstrated that each of the design parameters impacts the heterogeneity of the composite. Highheterogeneity allows improving the performance during the infusion process while reducing themechanical one. The optimization of the NCF using the design parameters requires setting acompromise in the heterogeneity of the architecture formed by the reinforcement. Another solutionwould consist in allowing the morphology to evolve during the infusion process, to go from an openstructure that eases the flow to a homogeneous structure safer for the windmill application.

Le sujet de la recherche est fondé sur l'étude du bord urbain-rural comme une structure territoriale qui accueille les dynamiques de contact, la transformation et l'hybridation des tissus. Le bord, à travers son épaisseur variable, est le milieu de l'interface, du changement, de la fragmentation et de la rupture. C’est intéressant d'étudier les caractères, la structure, les propriétés, les attributs, les adaptations que cet épaisseur assume, en se basant sur le caractère du lieu, la morphologie, l'utilisation des terres, sur la façon d'occupation de l'espace, sur les écologies relatives aux processus environnementaux et leurs implications dans le temps. C’est possible étudier spécifiquement ces phénomènes? Comprendre ses composantes, les raisons structurelles et de les interpréter dans une nouvelle pratique d’utilisation, d'emploi, de génération du bord? Le contact et les dynamiques qui en dérivent, nous permettent d'introduire le concept du changement d'état: la transmission des caractères d'un état à un autre (urbain-rural) comme nouvelle façon de lire les trasformations. La recherche est basée sur l'observation des études de cas en Sardaigne avec le but de construire une matrice de morpho typologies de paysages "en contact". L'objectif est pouvoir identifier et vérifier les processus de bord de qualité, et, par contre, les épisodes-processus qui affectent la qualité de ces espaces. Ces analyses seront réinterprétées sous forme de lignes directrices pour une révision plus consciente de l'espace du bord. / The theme of the search founds him on the urba-rural border study like a territorial structure that includes contact dynamics, the transformation and the hybridization among fabrics.The border, through his varying thickness, it is the place of the interface, of the mutation, of the fragmentation and the breakup. it is interesting to study the characters, the structures, the ownerships, the attributes, the adaptations that this thickness assumes, founding himself on the characters of the place, the morphologies, the uses of the ground, on the formalities of occupation of the space, on the ecologies related to the environmental trials and to their implications in the time. it is possible to study in the specific these phenomena? The contact among fabrics and the dynamics that derive of it, allows us to introduce the concept of passage of state, or rather the exachange of factors from a state to the other (urban-rural) as new way to read her transformations. The method of the search founds him on the observation and the analysis of a series of Sardinian cases study, with the objective to build a matrix of morfo typologies of "landscapes in contact". The objective is to be able to identify and to verify the processes of edge of quality and, contrarily, the episode-trials that injure the quality of the spaces. These analyses will constitute material of base for a reinterpretazione in the form of lines it drives for a more aware afterthought of the space of edge.

This research develops and tests a methodology for improving quality on a continuous process line. A nonwovens line was chosen as the experimental environment to test this methodology. First the process variables were analyzed and classified and a screening experiment was run to determine which variables had a significant effect on the quality measures--air permeability, caliper, basis weight, and appearance--of the filter media. Then a second experiment was run to study fewer variables in more detail. The data were interpreted with ANOVA and regression models. This research makes three general contributions: a methodology for improving quality on a continuous process line, the cause-and-effect relationships between some of the independent and dependent variables, and the second-order and third-order effects show the complexity of the research environment. / Master of Science

The use of methylchlorosilanes as an agent to produce water-repellent characteristics in cotton fabrics was patented by W.I. Patnode of the General Electric Company. Since very little information has been published on the process, this investigation was undertaken to determine the optimum conditions for treating cotton fabric. Experimental tests were made using 10 inch square samples of three different poplin type cotton fabrics dried to constant weight in a vacuum dryer and over P₂O₅ in a desiccator. Each cotton sample was treated with one of five different organo chlorosilanes or a mixture of methyltrichlorosilane and dimethyldichlorosilane. The time of contact between the fabric and silane was established at 60 seconds by a number of preliminary tests. Room temperature of approximately 30°C and pressure of approximately 710 mm were arbitrarily chosen for the reaction. The tests were made with the fabric in a three liter distilling apparatus and the required amount of silane for the volume concentration desired was vaporized and transported into the reactor by a difference in pressure of the vaporizer and reaction vessel. Fabric samples were supported in the reactor over a glass distributor ring which disbursed the silane. Volume concentrations of silanes of 0.1, 0.5, 1.0, and 5.0 percent were used in the investigation. Neutralization of end products was attempted with a 10 minute dried-air wash, 13-16 percent volume concentration of ammonia and five percent solution of sodium acetate. Data on results of tests on end products indicated the following conclusions: 1. Neutralization of end products is necessary to prevent deterioration of the fabric, as indicated by a maximum reduction in tensile strength of 80 percent as compared to an untreated sample. 2. The 60 second time of silane-fabric contact is sufficient to produce a water-repellent fabric. 3. Fabrics treated with a one percent volume concentration of mixtures of methyltrichlorosilane and dimethyldichlorosilane show a spray test rating of 90 as compared to a rating of 70-80 for fabrics treated with individual silanes. 4. Standard methods of testing treated fabrics do not indicate the hygienic properties of the treated fabrics. / Master of Science

Die Entwicklung von Geweben mit gestreckten Fadenlagen ist Gegenstand aktueller Forschungen, die vielfach Sondermaschinen für ganz spezielle Anwendungen hervorbringen. Eine systematische Analyse und Optimierung der unter Berücksichtigung der Verbundeigenschaften existiert nach bekanntem Stand des Wissens nicht. Ziel der Dissertation ist es, diese Lücke zu schließen und einen Beitrag zur Etablierung von Geweben mit gestreckten Fadenlagen in Faserverbundwerkstoffen zu leisten. Die Arbeit basiert zum Teil auf den Ergebnissen, die in der Zeit von 2006 – 2012 am Institut für Textilmaschinen und textile Hochleistungswerkstofftechnik der Technischen Universität Dresden im Rahmen verschiedener AiF und DFG Vorhaben entstanden sind. Weiterführende Überlegungen wurden 2015 – 2017 im Rahmen eines Promotionsstudiums an der Professur für Textile Technologien der Technischen Universität Chemnitz angefertigt. Wie anhand konkreter Ausführungsbeispiele gezeigt wird, stößt das Weben insbesondere für Anwendungen im Faserverbundleichtbau an technologisch bedingte Grenzen. Es erfolgt zunächst eine Gegenüberstellung konventioneller Flächenbildungsverfahren und der Anforderungen seitens der Endanwender, insbesondere aus dem Bereich der Verbundwerkstoffindustrie, gleichermaßen. Daraus wird ein Anforderungsprofil für ein anforderungsgerechtes Flächenbildungsverfahren abgeleitet und konstruktive Lösungsvorschläge zu dessen Umsetzung aufgezeigt. / The development of non-crimped-fabrics (NCF) is subject of current research activities. These often led to special machines for very special applications. There is no systematic analysis and optimization of the properties of composites based on the state of the art. The aim of this dissertation is to close this gap and to contribute to the establishment of woven NCF in fiber-reinforced composites. The work is based partially on the results obtained at the Institut für Textilmaschinen und textile Hochleistungswerkstofftechnik der Technischen Universität Dresden from 2006 to 2012 within the framework of various AiF and DFG projects. Further reflections were made between 2015 and 2017 as part of a doctoral study at the Chair of Textile Technologien der Technischen Universität Chemnitz. As shown from examples of the design, weaving is reaching technological limits, especially for applications in composite construction. First of all, conventional surface formation methods are compared with the requirements of end users, especially from the composites industry. From this, a requirement profile is derived for a requirements-based surface formation process and constructive proposals for solutions for its implementation are identified.

Call number: LD2668 .T4 1978 A55 / Master of Science

Call number: LD2668 .T4 1979 B69 / Master of Science

Call number: LD2668 .T4 1979 R65 / Master of Science