Brassica napus L., which is commonly known as canola, is the largest sources of edible oil in Canada. The remaining plant material, such as the stem, remains unused for any immediate application and is returned to the soil for decomposition. An investigation has been conducted to extract, characterize and modify the fibre materials from B. napus stems for textile and apparel applications. In order to find the optimum retting conditions for retting time, four different retting parameters were evaluated including, retting temperature, material liquor ratio, water exchange and the reuse of retted water. It was discovered that the virgin-retted fibres from Brassica plants exhibit most of the required textile properties including dye absorbency, strength, and thermal behaviour. However, the virgin-retted fibres do not exhibit the required spinning (yarn transformation) properties (softness, flexibility and individual fibre entity). In order to modify the Brassica fibres for spinnability, three treatment methods were applied: 1) alkali, acid and softener treatment; 2) pectinase enzyme treatment; and 3) enhanced enzyme treatment. According to Method 5 of the American Association of Textile Chemists and Colorists (AATCC), Brassica fibers obtained from treatments 2 and 3 showed similar spinning properties, and demonstrated superior spinning properties to Brassica fibres obtained from treatment one. To determine the variability of the cultivars upon textile and spinning properties, seeds from twenty different Brassica cultivars consisting of three different species, B. napus, B. juncea L. and B. rapa L., were collected, planted, and harvested upon reaching physiological maturity. The virgin water-retted fibre samples were then treated with pectinase enzyme, and different spinning properties (stiffness, softness, individual fibre entity) and textile properties (fibre decomposition temperature, tenacity and dye absorbency) of enzyme-treated samples were evaluated. The current research suggests that producing fibers from canola stubble and stems could be an additional income source for canola growers. / October 2016

This work consists of an investigation into the microstructure and mechanical behaviour of glass fibre reinforced polyester resin beams. The volume fraction occupied by glass fibres was 20-30%, which is that typically used in boat building. The beams tested were all unidirectional, with fibres oriented parallel or perpendicular to the long axis of the beam. Various techniques have been developed which may be applicable to other composite materials. The microstructure of the beams was investigated by observation of cross-sections using a Quantimet 720 Image Analysing Computer. Volume fractions and the distribution. of fibre cross-sectional areas were measured. Methods have been developed for the quantitative definition of the microstructure, in terms of the fibre arrangement. Cracks were grown in four-point flexural loading while monitoring acoustic emission. The acoustic emission circuit was built in the laboratory, and designed to monitor fibre failures only, one count being associated with one fibre failure. The processes of crack growth were further investigated by observation of fracture surfaces using a scanning electron microscope and measurement of crack profiles. The factors controlling the processes of crack growth have been elucidated. The material condition was monitored by specific damping capacity measurements. A free-free rig with excitation at the ends of the beam was developed. In addition measurements were made using a cantilever rig. Simple analyses involving the solution of the classical wave equation were carried out; a receptance analysis was also developed which allows the undamaged and cracked portions of the beam to be separated in the analysis. Invisible cracks, which had been indicated by acoustic emission, were successfully detected in both rigs. The correlation between recorded acoustic emissions and specific damping capacity measurements supports the validity of both techniques. Some correlation between properties and measured microstructures has been obtained here. These quantitative methods for the measurement of the microstructure of composite materials should prove very useful in a wide range of applications.

L'évolution de la transmission des données par fibre optique s'est accélérée ces dernières années. Le besoin de transmettre des débits plus élevés (aujourd'hui supérieurs ou égaux à 40 Gb/s) sur des longueurs de transmission de plus en plus grandes ne cesse de croître. Malheureusement la sensibilité aux défauts de propagation augmente avec le débit, que ce soit pour les effets linéaires dus à la dispersion chromatique (CD) et à la dispersion de mode de polarisation (PMD - polarization- mode dispersion) de la fibre, ou les effets non linéaires essentiellement induits par l'effet Kerr (variation de l'indice de réfraction en fonction de l'intensité lumineuse). Dans ce contexte, ce travail de thèse rapporte l'étude des effets de la CD et de la PMD sur les transmissions hauts débits. En outre, la PMD est identifiée aujourd'hui comme la principale source de limitation de la bande passante et de la capacité de transmission autorisées sur une fibre. Par ailleurs, la biréfringence dans les fibres optiques représente la cause principale de la dispersion de mode de polarisation (PMD).Dans ce travail, nous nous sommes focalisés plus particulièrement sur l'étude des effets de la température sur la PMD dans les fibres monomodes standards (SMF) correspondant à la spécification ITU-G.652 utilisées dans les réseaux de transmission longues distances. En tenant compte de l'ellipticité du cœur de la fibre, la variation de la PMD en fonction de la température est étudiée à travers l'évolution de la biréfringence en fonction du paramètre V de la fibre pour différentes températures. Ce travail de thèse ouvre la voie pour développer une architecture permettant de compenser la PMD par traitement numérique du signal. L'idée sous jacente est de remplacer une technologie coûteuse (composants optiques) par une architecture numérique à faible coût, et plus universelle. Les travaux en cours sur la compensation de la PMD par voie électronique sont encourageants et semblent très prometteurs à court terme / The evolution of optical fibre transmissions accelerated these last years. The need to transmit high bit rates (today equal to or higher than 40 Gb/s) over increasingly large lengths of transmission is constantly growing. Unfortunately, the sensitivity of propagation to defects increases with the bit rate. These effects are related to chromatic dispersion CD, polarization mode dispersion PMD, or to nonlinear effects primarily induced by the effect Kerr (dependence of the index of refraction of fibre of the light intensity). In this context, this work focuses on the study of the effects of CD and the PMD on the optical transmissions. Moreover, the PMD is identified today as the principal source of limitation in high bit rate transmissions. In addition to that, birefringence in optical fibres represents the principal cause of PMD. In this work, we particularly focused on the study of the effects of the temperature on the PMD in monomode standards fibres (SMF) corresponding to specification ITU-G.652 used in the optical networks. By taking into account of the ellipticity of the fibre, the variation of the PMD according to the temperature is studied through the evolution of birefringence according to the parameter V of fibre for various temperatures. This work of thesis opens the way to develop an architecture making it possible to compensate for the PMD by digital signal processing. The main idea is to replace an expensive technology (optical components) by a numerical architecture at low cost, and more universal. The works in progress on the compensation of the PMD by electronic way are encouraging and seem very promising at short-term

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The aim of this study is to investigate a novel toughening approach for liquid mouldable carbon fibre/epoxy composites. The toughening mechanism is based on the use of thermoplastics for the toughening of epoxy resins in which polymer blends are formed, leading to phase separated morphologies which allows for various toughening mechanisms to take place. Instead of standard melt or solution blending, the thermoplastic in this study is introduced as solid phenoxy fibres, which are combined with dry carbon fabric preforms. These phenoxy fibres remain solid during resin infusion and dissolve when the laminates are heated and phase separation takes place before curing completed. The main benefits of this approach are that the viscosity of matrix resin remains low, which makes liquid moulding of these laminates possible. Localised and selective toughening of particular regions within a structure can also be achieved. Process time and cost can also be reduced by eliminating the polymer blending process. It was found that modification with phenoxy improved composite Mode-I interlaminar toughness significantly, with an increase of up to 10-folds for bifunctional epoxy composite and 100% for tetrafunctional epoxy composite, while tensile properties were not adversely affected. It was found that it is possible to combine the dissolvable phenoxy fibres with an undissolved aramid interleaf to improve toughness and damage properties. However, the phenoxy-epoxy systems had lowered environmental stability and degraded after hot-wet and solvent conditioning.

One of the most significant challenges in the composite development field is to find a low-cost manufacturing route capable of producing large volumes of material. This thesis develops and characterises a potential avenue for addressing this, an induction furnace-based process. This process produced a composite of A357 matrix and 10% wt Dramix 3D 80/30 SL steel fibres. The method was evaluated by microstructural analysis and optimum casting parameters were approximated. The fibres were introduced to liquid A357 at 700°C and the composite was brought to a measured temperature of 650°C over not more than 120 seconds before being removed from the furnace and cooled. 10% wt was the ideal reinforcement ratio for this process. Characterising the tensile and compressive strength of the composite material, it reached a peak stress 130% higher than A357 produced under the same conditions, though the peak stresses were still 20% of the literature values for T6 tempered A357. This suggests the need for development of a temper which does not degrade the properties of the composite. 3-point bending tests and some tensile specimens also showed post-failure strength. Under dynamic loading, the composite showed a peak stress in excess of 100 MPa without reaching maximum compression under SHPB loading, and comparable performance to SiC-reinforced MMCs under ballistic testing. The linear decrease in work-hardening with increasing distance from the impact site shows shock and pressure-pulse dissipation properties, attributed to the difference in acoustic impedance between the matrix and the reinforcement.

This study deals with medium density wood fibre (MDF) and Kraft fibre reinforced polypropylene (PP) composites produced using extrusion followed by injection moulding. Initially, composites were produced with MDF fibre using 10, 20, 30, 40, 50 and 60 wt% fibre, and 1, 2, 3 and 4 wt% maleated polypropylene (MAPP) as a coupling agent. A fibre content of 50 wt% with 3 wt% MAPP was found to be optimum. Alkali treatment of fibre was carried out to improve the interfacial bonding. After treatment, fibre surface charge was found to increase, but single fibre tensile strength (TS) and Young's modulus were (YM) decreased. Alkali treatment reduced composite TS but increased YM. The effects of hemicellulose and residual lignin content were assessed with Kraft fibre (subjected to different stages of a standard Kraft pulping process and therefore consisting of different hemicellulose and residual lignin contents). Fibre surface charge was found to increase with decreasing residual lignin content. Composites containing higher amounts of lignin lead to lower TS and lower thermal stability. Composites were subjected to accelerated weathering for 1000 hours. TS and YM were found to decrease during weathering, and the extent of reduction was found to be higher for composites with higher residual lignin. The reduction of mechanical properties was found to be due to degradation of lignin and PP chain scission as evaluated by increase in PP crystallinity after weathering. As low lignin (bleached) Kraft fibre composites were found to provide superior mechanical properties, as well as more stable during accelerated weathering, further study including optimisation of MAPP content, effects of fibre contents, fibre length, fibre beating, hygrothermal ageing and recycling were carried out with bleached Kraft fibre. MAPP contents of 1, 2, 3, 4, 5, 7 and 10 wt% were used in Kraft fibre reinforced PP composites, and 3-5 wt% was found to be most favourable. Composite fibre content was varied between 30-50 wt%, and 40 wt% found to provide the maximum TS. To investigate the effects of fibre length on composites, fibre fractions of different length distribution were separated using a pressure screen. TS, YM and impact strength were found to decrease and failure strain (FS) increased with decreasing fibre length. To improve the interfacial bonding, the fibre was treated by mechanical beater. Fibre beating increased the TS of composites up to a certain point, beyond which TS decreased. Hygothermal ageing of composites was carried out by immersing specimens in distilled water at 30, 50 and 70 C over an 8-month period. Equilibrium moisture content and diffusion coefficient increased with increased fibre content in composites as well as with increased immersion temperature. Composites without coupling agent showed higher water uptake and diffusion coefficient than that of with coupling agent. After hygrothermal ageing the TS and YM decreased but FS and impact strength were found to increase. An investigation into the effects of recycling was carried out with composites containing either 40 wt% or 50 wt% fibre (bleached Kraft) with 4 wt% MAPP, and recycled up to eight times. For composites with 40 wt% fibre, TS and YM were found to decrease with increased recycling by up to 25% for TS and 17% for YM (after being recycled 8 times). Although TS was lower for virgin composites with 50 wt% fibre than for those with 40 wt% fibre, this initially increased with recycling by up to 14% (after being recycled 2 times), which was considered to be due to improved fibre dispersion, but then decreased with further recycling, and an overall 11% reduction of TS was found after recycling 8 times compared to the virgin composites. YM was higher for virgin composites with 50 wt% fibre than those with for 40 wt% fibre, and also initially increased with recycling but decreased upon further recycling. Recycling was found to increase thermal stability. The TS of composites made by combining recycled with virgin materials was also assessed. Hygrothermal ageing behaviour of recycled composites was also investigated by immersing specimens in distilled water at 50 C over a 9 month period. It was found that the diffusion coefficient and the equilibrium moisture contents of composites decreased with increased number of times the materials were recycled. After hygrothermal ageing, TS and YM of composites were found to decrease. However, the extent of reduction was found to decrease with increased recycling.

This thesis outlines the development of composite reinforcement technology for a ship's aluminium alloy superstructure. The work objective aimed to alleviate stress concentration in parts of the superstructure prone to fatigue-induced cracking. This is a novel approach to ship repair, which promises reduction in the cost of maintenance primarily due to greater efficiency and lower cost of repair. The work was conducted over approximately 12 years. It commenced in the late 80s with laboratory research and development and concluded in 2000 after completion of a seven-year trial on board a navy ship. Two carbon fibre composites, (5 m x 1 m consisting of a 25-ply laminate), were adhesively bonded to the 02-deck on the port and starboard sides. It was found that upgrading the structure using composites was effective, making it able to withstand service fatigue stresses. Finite element modelling and strain measurements on board the ship showed that critical stress concentration could be alleviated through stress redistribution. For the duration of the trial, no cracking of aluminium alloy deck in the vicinity of the reinforcements was reported. Both composite reinforcements exhibited good performance and remained in service after the end of the trial. However, the marine environment did cause some non-structural, edge debonding of the glass fibre reinforced overlay at the composite-metal interface. This overlay was designed to provide surface protection to the underlaying carbon reinforcement. Bond degradation was patchy. It occurred after about three years in service, most probably due to a combination of thermal cycling (solar heating/cooling) and water ingress at the interface. A new edge sealing method restored its durability and it required no further attention. This experiment was successfully demonstrated on board an active navy ship. The work proved that an effective and durable repair of a ship structure using non-metallic repair technology is feasible. Composite reinforcements prevented deck cracking and removed any need for welded repairs, thereby reducing the cost of ship maintenance. For further cost reduction it is recommended to adopt the principle of reverse engineering to simplify the technology for dockyard use.

This thesis involves an investigation in three areas; first, a study of an enzymatic-gravimetric method for the analysis of dietary fibre; second, a survey of dietary fibre intake in an area of a developing country, and finally, some observations on the functional aspects of gel-forming dietary fibre in the rat. A simple and rapid enzymatic-gravimetric assay for both soluble and insoluble dietary fibre has been critically investigated. Reference samples were also analysed by a more comprehensive, enzymatic gas chromatographic method to allow testing of the relative accuracy of the enzymatic-gravimetric method. The enzymatic-gravimetric method was found to be highly reproducible but gave a slightly higher value for total dietary fibre than the more comprehensive method. This discrepancy is probably due to the presence of small quantities of resistant starch and protein residue which are recovered in the enzymatic-gravimetric method. In the enzymatic-gas chromatographic method, protein residue is not measured, and resistant starch is estimated, but not counted as dietary fibre. The enzymatic-gravimetric method was applied to the analysis of foods commonly consumed in the Padang region of West Sumatra in Indonesia, in order to estimate dietary fibre intake in the region. Daily intakes of usual foods were estimated by use of a 24-hour recall procedure aided by food photographs to assist in the estimation of portion size. Samples of approximately 60 of the most commonly consumed foods were collected and analysed for dietary fibre. These appear to be the first data which report values for dietary fibre in Indonesion foods and they represent a significant improvement upon the existing data on crude fibre content. Knowledge of the amounts of foods usually consumed and their dietary fibre content allowed an estimation of usual intakes of dietary fibre. Fibre intake was found to be lower than in the developing countries of Africa and was comparable to intakes measured in the U.K. This is the first study to show that in this part of South East Asia, a developing country area using polished rice as a staple food, dietary fibre intakes are as low as in Western countries. Low intakes of fibre are believed to be related to the prevalence of a range of diseases and, in this study, preliminary data on the rates of non-infective, chronic diseases were collected from the two main hospitals in West Sumatra. Chronic, non-infectious diseases such as inguinal hernia, appendicitis, haemorrhoids, diabetes mellitus, hypertension and malignant neoplasms of the rectum are relatively frequent in West Sumatra. While no firm conclusions can be drawn from these data, they do show the possibility of a relationship between low intakes of dietary fibre and the prevalence of these diseases, and suggest that further investigation is necessary. Some observations were made of the effect of gel-forming dietary fibre on stomach emptying and intestinal transit rate in the rat. Xanthan gum was added to iso-osmotic solutions to produce increased viscosity and phenol sulphonphthalein (phenol red) was used as a non-absorbable marker. Gavage feeding of solutions with a range of viscosities was used to study the effect of viscosity on the rate of stomach emptying and intestinal transit. Increased viscosity was observed to slow gastro-intestinal transit and this provides one mechanism by which dietary fibre of the gel-forming type ray improve glucose tolerance.

A new Direct Simulation fibre model was developed which allowed flexibility in the fibre during the simulation of fibre suspension flow.This new model was called the �Chain-of-Spheres �model.It was hypothesised that particle shape and deformation could signi ficantly a ffect partic e dynamics,and also suspension bulk properties such as viscosity.Data collected from the simulation showed that flexible fibres in shear flow resulted in an order of 7 −10% bulk relative viscosity increase over the �rigid �fibre result.Results also es- tablished the existence of a relationship between bulk viscosity and particle sti ffness.In comparison with experimental results,other more conventional rigid fibre based methods appeared to underpredict relative viscosity.The flexible fibre method thus markedly improved the ability to estimate relative viscosity.The curved rigid fibre suspension also exhibited increased viscosity of the order twice that of the equivalent straight rigid fibre suspension.With such sensitivity to fibre shape,this result has some important implications for the quality of fibre inclusions used.For consistent viscosity,the shape quality of the fibres was shown to be important. The �Chain of Spheres �simulation was substantially extended to create a new simulation method with the ability to model the dynamics of arbitrarily shaped particles in the Newtonian flow field.This new �3D Particle �simulation method accounted for the inertial force on the particles,and also allowed particles to be embedded in complex flow fields.This method was used to reproduce known dynamics for common particle shapes,and then to predict the unknown dynamics of various other particle shapes in shear flow. In later sections, the simulation demonstrated inertia-induced particle migration inthe non-linear shear gradient Couette cylinder flow,and was used to predict the fibre orientation within a diverging channel flow.The performance of the method was verified against known experimental measurements,observations and theoretical and numerical results where available.The comparisons revealed that the current method reproduced single particle dynamics with great fidelity. The broad aim of this research was to better understand the microstruc- tural dynamics within the fibre-filled suspension and from it,derive useful engineering information on the bulk flow of these fluids.This thesis represents a move forward to meet this broad aim.It is hoped that future researchers may bene fit from the new approaches and algorithms developed here.