Hemp, one of the fast-growing plants with strong, durable fibers is being used for industrial applications, including papermaking, as a biodegradable reinforcing material for plastics as well as in construction. A series of tests has been conducted grinding hemp with the SM-220 Szego Mill equipped with three helically grooved, 30 cm long rollers with 8*8 or 4*4 mm grooves. A range of flow rates and rotational speeds has been covered in both dry and wet operation to determine the best processing conditions for various potential applications of refined hemp fibers. Particle size distributions and power consumption have been measured. Fiber length and diameter measurements allow an evaluation of fiber aspect ratio. For dry grinding, these are relatively low, typically in the 6-10 range. Wet grinding generally favors higher aspect ratios due to reduced fiber cutting and greater clearing action in the mill. Measured values are in the 60-80 range

Flax fibers can be used as environmentally friendly alternatives to conventional reinforcing fibers (e.g., glass) in composites. The interest in natural fiber-reinforced polymer composites is growing rapidly due to its high performance in terms of mechanical properties, significant processing advantages, excellent chemical resistance, low cost and low density. These advantages place natural fiber composites among the high performance composites having economic and environmental advantages. In the field of technical utilization of plant fibers, flax fiber-reinforced composites represent one of the most important areas. On the other hand, lack of good interfacial adhesion and poor resistance to moisture absorption make the use of natural fiber-reinforced composites less attractive. In order to improve their interfacial properties, fibers were subjected to chemical treatments, namely, mercerization, silane treatment, benzoylation, and peroxide treatment. Selective removal of non-cellulosic compounds constitutes the main objective of the chemical treatments of flax fibers to improve the performance of fiber-reinforced composites. The objective of this study was to determine the effects of pre-treated flax fibers on the performance of the fiber-reinforced composites. Short flax fibers were derived from Saskatchewan-grown flax straws, for use in fiber-reinforced composites. Composites consisting of high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE) or HDPE/LLDPE mix, chemically treated fibers and additives were prepared by the extrusion process. Extrusion is expected to improve the interfacial adhesion significantly as opposed to simple mixing of the two components. The extruded strands were then pelletized and ground. The test samples were prepared by rotational molding. The fiber surface topology and the tensile fracture surfaces of the composites were characterized by scanning electron microscopy to determine whether the modified fiber-matrix interface had improved interfacial bonding. Mechanical and physical properties of the composites were evaluated. The differential scanning calorimetry technique was also used to measure the melting point of flax fiber and composite. Overall, the scanning electron microscopy photographs of fiber surface characteristics and fracture surfaces of composites clearly indicated the extent of fiber-matrix interface adhesion. Chemically treated fiber-reinforced composites showed better fiber-matrix interaction as observed from the good dispersion of fibers in the matrix system. Compared to untreated fiber-reinforced composites, all the treated fiber-reinforced composites had the same tendency to slightly increase the tensile strength at yield of composites. Silane, benzoylation, and peroxide treated fiber-reinforced composites offered superior physical and mechanical properties. Strong intermolecular fiber-matrix bonding decreased the high rate of water absorption in biocomposites. The incorporation of 10% untreated or chemically treated flax fibers also increased the melting point of composites. Further investigation is required to address the effect of increase in fiber content on the performance of composites.

Flax fibers can be used as environmentally friendly alternatives to conventional reinforcing fibers (e.g., glass) in composites. The interest in natural fiber-reinforced polymer composites is growing rapidly due to its high performance in terms of mechanical properties, significant processing advantages, excellent chemical resistance, low cost and low density. These advantages place natural fiber composites among the high performance composites having economic and environmental advantages. In the field of technical utilization of plant fibers, flax fiber-reinforced composites represent one of the most important areas. On the other hand, lack of good interfacial adhesion and poor resistance to moisture absorption make the use of natural fiber-reinforced composites less attractive. In order to improve their interfacial properties, fibers were subjected to chemical treatments, namely, mercerization, silane treatment, benzoylation, and peroxide treatment. Selective removal of non-cellulosic compounds constitutes the main objective of the chemical treatments of flax fibers to improve the performance of fiber-reinforced composites. The objective of this study was to determine the effects of pre-treated flax fibers on the performance of the fiber-reinforced composites. Short flax fibers were derived from Saskatchewan-grown flax straws, for use in fiber-reinforced composites. Composites consisting of high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE) or HDPE/LLDPE mix, chemically treated fibers and additives were prepared by the extrusion process. Extrusion is expected to improve the interfacial adhesion significantly as opposed to simple mixing of the two components. The extruded strands were then pelletized and ground. The test samples were prepared by rotational molding. The fiber surface topology and the tensile fracture surfaces of the composites were characterized by scanning electron microscopy to determine whether the modified fiber-matrix interface had improved interfacial bonding. Mechanical and physical properties of the composites were evaluated. The differential scanning calorimetry technique was also used to measure the melting point of flax fiber and composite. Overall, the scanning electron microscopy photographs of fiber surface characteristics and fracture surfaces of composites clearly indicated the extent of fiber-matrix interface adhesion. Chemically treated fiber-reinforced composites showed better fiber-matrix interaction as observed from the good dispersion of fibers in the matrix system. Compared to untreated fiber-reinforced composites, all the treated fiber-reinforced composites had the same tendency to slightly increase the tensile strength at yield of composites. Silane, benzoylation, and peroxide treated fiber-reinforced composites offered superior physical and mechanical properties. Strong intermolecular fiber-matrix bonding decreased the high rate of water absorption in biocomposites. The incorporation of 10% untreated or chemically treated flax fibers also increased the melting point of composites. Further investigation is required to address the effect of increase in fiber content on the performance of composites.

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Nowadays Optical fiber communication is one of the important way to convey information, and there is strong competition in optical long-haul transmission to achieve high channel bit rates and large transmission capacity. Therefore, it is important to study a technology to improve the performance of such system. As we have already known, the dispersion flattened fiber (DFF) and Return-to-zero differential phase shift keying (RZ-DPSK) modulation are attractive, because it can improve the transmission performance of the long-haul system, therefore, it is possible to improve the transmission performance by a combination of the RZ-DPSK and the DFF, and the performance improvement investigation is required, because it will contribute to improve the system design of the long-haul optical fiber communication systems in near future. In this master thesis, a theoretical study focused on the RZ-DPSK transmission system using DFF is conducted. One important technology of current long-haul optical fiber communication system is a dispersion map. In this master thesis, difference of the transmission performance is characterized with regard to number of dispersion blocks within the dispersion map, different repeater output power and different compensation scheme within dispersion map, etc., all of them calculated by a numerical simulator .The goal is to clarify the optimum dispersion map design of the long-haul DPSK based transmission and find the effective method to improve the transmission performance.

The purpose of this thesis is to understand dynamic behaviors of carbon fiber composite golf shaft and the influence of different carbon fiber shaft flexes on club heads. To achieve the purpose, the researcher used the finite element method (FEM) software LS-DYNA and ANSYS to analyze the dynamic behaviors of carbon fiber composite golf shaft. He also applied three rigid bodies and two revote joint in a swing mode to simulate swing motion. In the same driving moment, the comparison provides golfer with a reference for selecting suitable carbon fiber composite golf shaft. It also offers other researchers an FEM model to do further analysis of dynamic behaviors of golf heads with the carbon fiber composite shaft.

The success in fabrication of Cr-doped fibers (CDFs) with fluorescence of Cr3+ by powder-in-tube (PIT) method equipped with drawing-tower process is demonstrated. However, the fabrication by using powder-in-tube (PIT) with redrawing technique provides a better solution to improve the concentration of Cr-ion to enhance the fluorescence of CDFs. The Cr-doped powder was composed of CaO-Al2O3-BaCO3-MgO-Cr2O3 as the material of core. The CDFs had a 7 £gm core and a 125 £gm cladding. The transmission loss was 0.27 dB/cm at 1550 nm and a core non-circularity of less than 3% for the CDFs are achieved. The fluorescence intensity of Cr3+ between 800~1200 nm was 6 nW/nm. The optical fiber fabrication processes, whether the preform is made by MCVD(Modified Chemical Vapor Deposition), RIT(Rod-in-Tube) or PIT, the inter-diffusion between core and cladding materials is an inevitable issue at such high fiber drawing temperature. Since SiO2 is amajor component in the cladding, SiO2 will certainly diffuse into the core region and become one of the new constituents in the core. The Cr-doped powder was composed of SiO2- Al2O3-MgO-K2O-TiO2-Cr2O3 as the material of core. The CDFs had a 10 £gm core and a 125 £gm cladding. The fluorescence intensity of Cr4+ between 900~1300 nm was 200 pW/nm. The CDFs were successfully fabricated by using podwer-in-tube with redrawing technique. The demonstration of CDFs makes it possible as a new generation broadband fiber amplifier and a broadband source for high resolution OCT.

Abstract The objectives of the thesis are to study and research the function of the fuel cell¡¦s bipolar plate which is vital to the Proton Exchange Membrane fuel cell¡Aand to create a new bipolar plate composed of nonhomogeneous plate and conductive object which conductive object are put through light weight plastic plate in consideration of low cost¡Bmini size¡Blight weight and high efficiency¡Atogether with a series of test for its capability. Of the same section area¡Athe electric resistance of carbon fiber used in this experiment is lower than traditional graphite bipolar plate.According to related literature¡Athe resistant of the graphite bipolar plateis lower than the ones made of other materials or composite material.The carbon fiber is a suitable conductive object for bipolar plate consequently. Without leakage¡Athe material are stand the differential pressure up to 0.5 kg/cm2 through the leakage/pressure tests.It is good enough in most of practical application.The strength of bipolar plate to resist the differential pressure is related to the plate strength and the strength of bond¡Ainterface between bond and plate or bond and carbon fiber.The proper bond is very important in this case. The efficiency of fuel cell decreases rapidly in line with the increase of loading during the efficiency test of fuel cell and sudden drop portion situates at Ohm resistance domain.Other papers describe about the main factor of Ohm resistance domain is resistance loss¡Aparameter include conductive coefficient¡Barea of conductive material¡Blength of conductive material.The most different of experiment compare with previous is the area of conductive material.Therefore the area of conductive fiber in bipolar plate influences the efficiency of fuel cell a lot. Through the research¡Athe availability of the new bipolar plate composed of nonhomogeneous plate and conductive object is proven and the cause of its defect in efficiency is identified for improvement in practical application.

A new scheme of fabricating the tapered hyperbolic-end fibers (THEFs)microlenses using unique etching and fusion techniques is proposed. TheTHEFs were fabricated by symmetrically tapering the fiber during theetching process and hyperbolically lensing the tip during the fusing process.The tapered hyperbolic microlenses have demonstrated up to 82% couplingefficiency for a laser with an aspect ratio of 1:1.5. The influence of the tapering asymmetry on the coupling has also been investigated experimentally and theoretically. The axially symmetrical taperedmicrolenses of the THEFs showed that far-field profiles were well approximated to a Gaussian profile, while the asymmetric taper had deviated significantly from a Gaussian profile. A theoretical analysis illuminated a larger wavefront transformation of the hemispherical microlenses. A lesser phase aberration of the normalized optical path difference (OPD) was found in the hyperbolic-end lens, and that resulted in more than 2 dB improvement in the coupling efficiency when compared to the currently available hemispherical microlenses. The high-coupling performance of the hyperbolic microlens was due to an improved wavefront matching between the laser and the fiber, which was one of the most important contributions in this study.The 1.55 µm fiber grating external cavity lasers (FGECLs), packaged with THEF microlens for coupling the fiber grating external cavity, have been investigated for different combinations of coupling efficiency (£b) and Bragg reflectivity (Rg). Various tapered hyperbolic-end fiber microlenses with different coupling efficiency have been fabricated for this study. The FGL of higher £b = 72% and Rg = 0.52 has a stronger resonant feedback as the spectral output showed a single longitudinal mode with the side-mode-suppression-ratio (SMSR) greater than 45dB, a high output power of greater than 5mW, and a lower threshold current. However, for the case of £b = 68% and Rg = 0.35, the FGL exhibited a more stable SMSR against the variation of pumping current and temperature. Numerical simulations have also been performed on the SMSR at different coupling efficiencies and Bragg reflectivity for the FGLs. The high performance of the FGLs can be achieved through a higher coupling efficiency between a laser diode and a single-mode fiber. The calculated SMSR showed an excellent agreement with the measured data.