Thesis (M.S.)--Brigham Young University. Dept. of Technology, 2004. / Includes bibliographical references (p. 191-195).

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 13, 2007). Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 194-205). Available also in a digital version from Dissertation Abstracts.

Orientador: Janete Dias Almeida / Banca: José Benedito Oliveira Amorim / Banca: Emília Ângela Loschiavo Arisawa / Resumo: A hiperplasia fibrosa inflamatória (HFI) é um processo proliferativo não neoplásico, encontrado em mucosa bucal, geralmente decorrente de traumatismos crônicos. A Espectroscopia Raman fornece informações dos tecidos avaliados através de suas propriedades ópticas. Tem sido empregada em estudos biológicos para a caracterização de alterações neoplásicas. No entanto, são escassos os estudos que envolvam processos inflamatórios. Objetivou-se caracterizar através da Espectroscopia FT-Raman HFI com tecidos bucais normais de mucosa jugal, avaliando a especificidade e a sensibilidade deste método, relacionando os espectros obtidos aos achados histopatológicos. Foram utilizados 19 amostras de HFI e 6 amostras de mucosa normal (MN) que localizavam-se em mucosa jugal, obtendo-se, totalizando 92 espectros de HFI e 27 espectros de MN. Os resultados demonstrados pela análise dos componentes principais revelaram que PC3 e PC5 foram os responsáveis por uma melhor classificação, podendo ser observada no gráfico de loading plots como espectros com picos invertidos. Pela análise de discriminantes linear, foi possível observar que 19 espectros de MN e 85 espectros de HFI foram classificados corretamente, correspondendo, respectivamente, a 70,4 % e 92,4 % do total de dados. A curva de Roc revelou um valor preditivo do modelo de 0,87. Concluiu-se que a análise dos espectros Raman permitiu detectar similaridades e diferenças biológicas e bioquímicas entre HFI e MN de mucosa jugal, demonstrando que a Espectroscopia Raman apresenta sensibilidade e especificidade no diagnóstico de processos proliferativos não neoplásicos. Observou-se correlação entre os achados histopatológicos e os obtidos pela utilização da técnica. / Abstract: Inflamatory fibrous hyperplasia (IFH) is considered a non-neoplasic proliferative process that generally occurs in association to trauma. This pathology has typical hystopathological features in both epithelial and conjunctive tissues. Raman spectroscopy of pathological tissues has become a reality that can contribute to knowledge enhancement about biochemical alteration making possible the differential diagnosis of oral pathologies. The objective of the present study was to use FT-Raman Spectroscopy to identify biological and biochemical alterations that exist between oral IFH in buccal mucosa and normal tissue from the same site. Therefore 92 spectra of inflammatory fibrous hyperplasia from 19 patients were compared to 27 spectra of normal tissue from6 patients. It was observed that the relation between the data of IFH and normal tissue was more evident when the Principal Components Analysis (PCA) of all spectra were calculated and when the Principal Components (PC) PC3 vs. PC5 were analysed. Results of Box Plot show great differences in normal group. This was confirmed by the analysis of the Loading Plot of the PC's that showed great modifications between normal and IFH identified by inverted peaks in Raman band 500 e 1110 cm-1; 1300, 1580 and 1730 cm-1. These bands correspond mainly to molecular vibrations of lipids, collagens (I and III) and proteins. The predictive value of diagnostic model was calculated by linear discriminates analysis that showed 0,87 ROC curve. Biological and biochemical similarities and differences between IFH and normal tissues were confirmed by Raman Spectroscopy when compared to hystopathologycal analysis. / Mestre

The various topics investigated in the course of the preparation of this thesis can by unified under the common theme of fibrous fIltration enhancement from both experimental and theoretical perspectives. Fibrous filtration is by far the most common method of gas pUrification in use today and further improvements will require a better understanding of the various mechanisms contributing to the collection of particles. The lack of agreement between experimental results and the latest theoretical models found in the literature which have been put forward to predict fIlter efficiency led to the development of a complex computer simulation of a fIltration process. The model simultaneously accounts for particle collection in the inertial impaction, interception and Brownian diffusion regimes and also recognizes that real fIlters do not consist of a simple array of fibres, but are a complex mixture of fibres positioned randomly in space. Test fIlters carefully manufactured from well characterized glass fibre components were used to challenge monosize sodium chloride aerosols. Since most of the filtration parameters are known, our model was used and directly compared with the leading theoretical models and our experimental results. The enhancement of fibrous filters by gradual clogging was investigated. The filtration characteristics; pressure drop and upstream & downstream concentrations were monitored as loading progressed. A discussion of the changes in the quality factor which was found to be dependent upon aerosol size is given. The fractal dimension of the particle deposits on individual fibres was measured and found to be dependent on the fIltration dynamics present. The fundamental forces of electrostatic filtration (Coulomb, image and polarization forces) were clearly demonstrated in a system of test aerosols and fibrous fIlters which were identical except for the amount of charges the particles and fibres contained. The size ranges in which these forces are effective were accurately measured.

Magister Scientiae Dentium - MSc(Dent) / Ossifying fibroma (OF) is the most frequent of the three fibro-osseous lesions of the jaws. It occurs mostly in patients between the age of 20 and 40 years. Females are more commonly affected than males. Clinically, OF usually presents as a painless expansive intra-bony mass. Swelling and pain may be present in some cases while some lesions are discovered incidentally. Radiographically, OF is usually well-defined and unilocular or multilocular. Early lesions present as well-defined radiolucency that are small in size. Over time, the lesions tend to enlarge in size and become mixed radiolucent-radiopaque and finally become completely radiopaque. The aim of this study was to determine the clinical and radiological features of ossifying fibroma presenting at the Departments of Maxillo-Facial and Oral Surgery and Diagnostics and Radiology, University of the Western Cape Oral Health Centre as well as to assess its management and recurrence patterns. A retrospective case series analysis was performed of all histopathologically diagnosed ossifying fibroma cases available at the Departments of Maxillo-Facial and Oral Surgery and Diagnostics and Radiology at the Faculty of Dentistry, University of the Western Cape from 1976-2014. Patient's age, gender and ethnicity were recorded. The clinical presentation of the lesion as well as the history was analyzed. Radiographic features including density, size, shape, location, locularity and its effect on adjacent structures was noted. Management of each case and follow-up was also documented. A total 61 cases were included in the study. The majority of patients were females (63.9%) and below 40 years of age (73.9%). Few cases were symptomatic (29.5%) with an average period 22 months from first symptoms to presentation. The mandibular posterior region was most affected (55.5%) while larger lesions occurred more frequently in younger patients. Majority of lesions were radiopaque (49.2%) and had well-defined margins (93.6%). Most cases were managed by surgical curettage (68.2%). Following an average follow-up period of 20 months only one case recurred (recurrence rate =6.7%). In conclusion, the majority of the clinical and radiographic findings of ossifying fibroma were similar in South African patients as those of other populations. Differences include that the lesions in this population were more radio-opaque and larger in size than in the reported literature. Surgical curettage is an acceptable management protocol with low rate of recurrence.

Submitted in fulfilment of the requirements for the degree of Master of Engineering: Mechanical Engineering, Department of Mechanical Engineering, Faculty of Engineering and the Built Environment, Durban University of Technology, Durban, South Africa. 2017. / In this study, the fatigue life of fiber reinforced composite (FRC) materials system was investigated. A nano-filler was used to increase the service life of the composite structures under cyclical loading since such structures require improved structural integrity and longer service life. Behaviour of glass fiber reinforced composite (GFRC) enhanced with various weight percentages (1 to 5 wt. %) of Cloisite 30B montmorillonite (MMT) clay was studied under static and fatigue loading. Epoxy clay nanocomposite (ECN) and hybrid nanoclay/GFRC laminates were characterised using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The mechanical properties of neat GFRC and hybrid nanoclay/GFRC laminates were evaluated. Fatigue study of the composite laminates was conducted and presented using the following parameter; matrix crack initiation and propagation, interfacial debonding, delamination and S–N relationship. Residual strength of the materials was evaluated using DMA to determine the reliability of the hybrid nanoclay/GFRC laminates. The results showed that ECN and hybrid nanoclay/GFRC laminates exhibited substantial improvement in most tests when compared to composite without nanoclay. The toughening mechanism of the nanoclay in the GFRC up to 3 wt. % gave 17%, 24% and 56% improvement in tensile, flexural and impact properties respectively. In the fatigue performance, less crack propagations was found in the hybrid nanoclay/GFRC laminates. Fatigue life of hybrid nanoclay/GFRC laminate was increased by 625% at the nanoclay addition up to 3 wt. % when compared to neat GFRC laminate. The residual strength of the composite materials revealed that hybrid nanoclay/GFRC showed less storage modulus reduction after fatigue. Likewise, a positive shift toward the right was found in the tan delta glass transition temperature (Tg) of 3 wt. % nanoclay/GFRC laminate after fatigue. It was concluded that the application of nanoclay in the GFRC improved the performance of the material. The hybrid nanoclay/GFRC material can therefore be recommended mechanically and thermally for longer usage in structural application. / M

Fiber-yielding plants is an area of increased interest due to the potential use in a variety of green-based materials. These biocomposites can be incorporated into multiple uses; for example, to replace building materials and interior vehicular paneling. The research here aims to focus in on the crop Hibiscus cannabinus for utilization into these functions. H. cannabinus is economically attractive due to the entire process being able to be accomplished here in the United States. The plant can be grown in a relatively short growth period (120-180 days), and then processed and incorporated in a biocomposite. The plant fiber must first be broken down into a useable medium. This is accomplished by the retting process, which occurs when microbial constituents breakdown the heteropolysaccharides releasing the fiber. The research aims to bridge the gap between the primitive process of retting and current techniques in molecular and microbiology. Utilizing a classical microbiological approach, which entailed enrichment and isolation of pectinase-producing bacteria for downstream use in augmented microbial retting experiments. The tracking of the bacteria was accomplished by using the 16S rRNA which acts as “barcodes” for bacteria. Next-generation sequencing can then provide data from each environment telling the composition and microbial diversity of each tested variable. The main environments tested are: a natural environment, organisms contributed by the plant material solely, and an augmented version in which pectinase-producing bacteria are added. In addition, a time-course experiment was performed on the augmented environment providing data of the shift to an anaerobic environment. Lastly, a drop-in set was performed using each isolate separately to determine which contributes to the shift in microbial organization. This research provided a much needed modernization of the retting technique. Previous studies have been subject to simple clone libraries and growth plate assays and next-generation sequencing will bring the understanding of microbial retting into the 21st century.

Both in-situ and ex-situ giant pandas (Ailuropoda melanoleuca), display shifts in bamboo species and part preference throughout the year. The effects of this shifting preference on gastrointestinal (GIT) microbiota were observed using traditional culturing methods to characterize normal GIT microflora from fecal samples and behavioral feeding data of adult male and female pandas over a fourteen-month period. Linear and quadratic fits were used to determine any significant relationships between the time of year and part preference on the GIT microflora (P<0.05). Significant values for time of year were observed with the linear fit in total aerobes (P-value=0.0368), streptococci (P-value=0.0120), and lactobacilli (P-value=0.0166) and quadratic fits in streptococci (P-value=0.0382) and Bacteroides spp. (P-value=0.0134) at á=0.05. Significant linear relationships were observed with part preference and lactobacilli and Bacteroides spp., P-values of 0.0028 and 0.0030, respectively, indicating that part preference and time of year may affect the flux of panda GIT microflora.