Thesis (doctoral)--Universität Köln, 1987. / Vita. Includes bibliographical references (p. 85-97).

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Das, Suman; Committee Member: Halloran, John; Committee Member: Henderson, Clifford; Committee Member: Kalaitzidou, Kyriaki. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph. D.)--Columbia University, 1946. / Vita. Bibliography: p. 61.

Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--Universität Bern. / Includes bibliographical references.

Thesis (Ph. D.)--Washington State University, May 2007. / Includes bibliographical references.

Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, 2007. / A thesis submitted for the degree of Doctor of Philosophy, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2007. Typescript. Includes bibliographical references.

L’analyse et la classification de 31 résines végétales par différentes méthodes analytiques (HPTLC, CPL-UV, CPL-DEDL, CPL-SM, CPG-SM et RMN) a été réalisée dans un but d’établir un lien de parenté entre l’identité chimique d’une résine et son appartenance botanique. Les résines naturelles étant riches en dérivés triterpéniques une étude de leur détection par spectrométrie de masse (SM) a été menée montrant l’intérêt de l’ionisation douce pour cette famille moléculaire et l’avantage des sources APCI et APPI pour une détection sensible en LC-MS e ces composés. Ces métabolites secondaires peu polaires et très riches en isomères, ont nécessité la mise au point des méthodes d’extraction et de séparation efficace pour permettre l’amélioration de leur rendement d’extraction et faciliter leur identification dans leur milieu naturel. Trois dérivés triterpéniques ont été identifiés pour la première fois dans l’une des résines étudiées (Manilkara bidentata) et leur activité biologique a été testée sur des cellules de peau humaine en culture. / The aim of this research was to analyze and classify 31 natural resins using different analytical tools (HPTLC, LC-UV, LC-ELSD, LC-MS, GC-MS and NMR) in order to verify the link between the chemical composition of resins and their botanic belongs. Natural resins are mostly composed from triterpens that is the reason why development of sensitive liquid chromatography method hyphenated to mass spectrometry detection was necessary. APPI and APCI were proved to be the most adequate sources of ionization for triterpens mass spectrometry analysis. Triterpens have low polarity index and contain number of isomers making their extraction and separation difficult in liquid chromatography. To improve their extraction and separation in their natural matrix, different parameters were considered. Finally, three triterpens derivatives were described for the first time in Manilkara bidentata resin and their bio-activity was tested on human skin cells cultures.

OBJECTIVES: Fiber-reinforced composite has been commercialized as universal and flowable resin based composite. The objective of this study is to test and compare fracture toughness of fiber-reinforced composite resins to conventional particulate filler composite resins. MATERIALS AND METHODS: Four products were tested in this study, including: GC everX Posterior (EXP), 3M ESPE Filtek Supreme Ultra Universal (FSU), 3M ESPE Filtek Supreme Ultra Flowable (FSF), Nanova Biomaterials NovaPro Flowable (NPF), Nanova Biomaterials NovaPro Universal (NPU), Prime Dental Manufacturing Prime­ dent flowable (PDF). NovaPro contains hydroxyapatite nanofiber as filler and everX has glass fiber as filler. Materials were tested by creating specimens in two configurations using metallic molds (n=5 or 10/group). Flexural toughness specimens were rectangles 2.5×5×25mm with a slot and V­notch of 1x2.4mm with at the central edge. All specimens were made following manufacturer’s instructions under 1,470mW/cm2 light curing. After setting and de­molding, specimens were kept in 37oC water for 72 hours. Testing was performed on an Instron machine (Model 5566A) with a three-point bending fixture at a cross­head speed of 0.25 mm/sec and V­notch faced to tensile side. One­way ANOVA post hoc Tukey HST (JMP Pro 12.0.) was used for data analysis (significance level = 0.05). RESULTS: Fracture toughness results are shown in Table 1. There was significant difference among groups. CONCLUSIONS: Composites with fiber fillers showed significant higher fracture toughness. / 2020-07-23T00:00:00Z

Advance composite materials based mainly on epoxy resins are being used in increasing amounts in aerospace components due to their high strength:weight ratio. Such components have to survive in a range of temperature and humid environments in different parts of the world. The current generation of epoxy resins used in high performance fibre reinforced laminates absorb moisture from the atmosphere. Moisture absorption by the epoxy resins leads to a reduction in glass transition temperature and to a softening of the resin with a loss of resin stiffness and strength. In certain applications the components have to survive low impacts from dropped tools and rough handling during maintenance. Low energy impacts of this nature are considered potentially dangerous mainly because the damage might be left undetected. Even where no visible impact damage is observed at the surface, matrix cracking and interlaminar failure can occur, and the load carrying properties of the composite components is considerably reduced. A compression after impact (CAI) test is widely used in industry as the major screening parameters for materials selection. The aim of the work reported in this thesis was to determine the influence of thermohumid conditions on CAI properties and to assess the degradation behaviour of composite laminates under these thermohumid conditions.