LCA was used to compare the environmental impacts of two different passenger tubs being designed for the GO-4 vehicle. Based on the results, the adoption of biomaterials clearly displays many benefits. / May 2017

Bibliography: leaves 106-132. This project investigated the role of VAM fungi in the growth and nutrition of Linum usitatissimum L. in agricultural soils in southern Australia. It had two general aims: (1) to examine the role of indigenous VAM fungi in the growth and nutrition of linseed in field soil collected near Clare, South Australia; and (2) to examine the effect of VAM fungi on the Zn nutrition of Linola.

Museum textiles provide priceless documentation of the activities of people throughout time. They record human interests and serve as resources for students of many disciplines. In New Zealand there are artefacts made from Phormium tenax which are extremely important in terms of providing a record of early New Zealand life and links to our past as both artistic and cultural symbols: they present an insight into the many faceted nature of early Maori culture. However there are some which are clearly in need of preservative treatment. Others may need care in the future for inevitably they are, or will be, subject to degradation during storage, when on display and during cleaning and refurbishing. Conservators, who embark occasionally on restorative treatments designed to reverse or arrest the symptoms of degradation, have begun to address the causes and future fundamental affects of their procedures. However there have been few scientific studies of the properties of the fibres and, therefore, there is little information to help the conservators in their tasks. This study has a twofold purpose. The first aim is to provide a short survey of the literature on Phormium and relate it to other lignocellulosic fibres. The emphasis in the survey is to put the conservation problem in context and to point to those technical articles which may be relevant to someone dealing with ancient materials. Secondly there is a practical study of the impact of heating the fibres in the absence and presence of oxygen and in water. These two agencies are ones which are directly relevant to the conservator.

The effect of fractionating flax, peas and canola on the digestibility of these ingredients in <i>Nile tilapia</i> was determined. Dehulling of flax, and processing peas and canola to pea protein concentrate and canola protein concentrate, resulted in significant increases in the energy and dry matter digestibilities of these products (P < 0.05). Protein digestibility was significantly improved by dehulling flax but there were no differences in the protein digestibilities of pea, canola and their protein concentrates. The ability of the most digestible ingredients from Experiment 1 to replace fish meal in tilapia diets was examined in a 9 week growth trial. The diet formulations were arranged in a 2 x 4 factorial design with 2 types of plant protein mixtures used to replace fish meal (simple: soyabean meal and maize gluten meal or complex: soyabean meal, maize gluten meal, dehulled flax, pea protein concentrate and canola protein concentrate) and 4 levels of protein originating from fish meal (100%, 67%, 33% and 0%). Diets were formulated to contain equal digestible protein (380 g kg-1) and digestible energy (17.63 MJ kg-1). Fifty six tanks containing 10 male <i>Nile tilapia</i> were used in this experiment. Fish were fed to apparent satiation twice daily for a total of 63 days and growth and feed intake was measured for the entire experimental period. On day 64 of the experiment, one fish per tank was euthanized and a 1 cm segment of small intestine was prepared for measurement of villus length. The average daily gains, specific growth rates and feed efficiencies of fish fed diets with 0% fish meal were significantly lower than fish fed diets with the 33, 67 or 100% fish meal levels. Fish fed the complex diets had significantly higher average daily gains, specific growth rates, feed:gain ratios and protein efficiency ratios than those fed the simple diets. Villus length decreased with decreasing levels of fish meal and increased with increased diet complexity but the effects were not significant. The results indicated that replacement of fish meal with a complex mixture of plant ingredients may allow a greater replacement of fish meal in diets fed to <i> Nile tilapia</i>.

Flax fiber-reinforced plastic composites have attracted increasing interest because of the advantages of flax fibers, such as low density, relatively high toughness, high strength and stiffness, and biodegradability. Thus, oilseed flax fiber derived from flax straw, a renewable resource available in Western Canada, is recognized as a potential replacement for glass fiber in composites. Among plastics, polyethylene is a suitable material for use as a matrix in composites. However, there are not many studies in this area. Therefore, the main goal of this research was to develop flax fiber-polyethylene (PE) biocomposites via injection molding and investigate the effect of material properties and processing parameters on their properties. <p>Alkali, silane, potassium permanganate, sodium chlorite, and acrylic acid treatments were employed to flax fiber to decrease the hydrophilic of fiber and improve the adhesion between the fiber and the matrix. All chemically treated fiber-HDPE biocomposites had higher tensile strength and lower water absorption compared with non-chemically treated ones. Acrylic acid treatment of the fiber resulted in slight increase in its degradation temperature; using this treated fiber resulted in biocomposites with the best performance. Therefore, the morphological, chemical, and thermal properties of acrylic acid treated fiber were also studied. <p>Linear Low Density Polyethylene (LLDPE) and High Density Polyethylene (HDPE) were the main matrices investigated in this research. Showing a high tensile strength and similar water absorption, HDPE was used as the matrix in further research. Flax fiber with 98-99% purity was chosen as reinforcement since the flax shive mixed with the fiber decreased the tensile and flexural properties but increased the water absorption of the biocomposite. <p>Acrylic acid-treated fiber-HDPE biocomposites had been developed through injection molding under different processing conditions. Increasing the fiber content of biocomposite increased its tensile and flexural strengths, especially flexural modulus, but its water absorption capacity also increased. It was possible to improve the mechanical properties of biocomposites and decrease the water absorption by adjusting injection temperature and pressure. Injection temperature had more influence on the quality of the biocomposite than injection pressure. Injection temperature lower than 195°C was recommended to achieve good composite quality. <p>Melts of HDPE and flax fiber-HDPE biocomposites were categorized as power-law fluids. Apparent viscosity, consistency coefficient, and flow behavior index of biocomposites were determined to study their flow behavior. The statistical relationship of these parameters with temperature and fiber content were modeled using the SAS and SPSS softwares. The injection filling time was related to the material rheological properties: biocomposites required longer filling time than pure HDPE. Low injection temperature also resulted in long filling time.<p>The thermal conductivity, thermal diffusivity, and specific heat of biocomposites containing 10, 20, and 30% fiber by mass were determined in the processing temperature range of 170 to 200°C. Fiber content showed a significant influence on the thermal properties of the biocomposites. The predicted minimum cooling time increased with the thickness of the molded material, mold temperature, and injection temperature, but it decreased with the ejection temperature.

The environmental menace associated with the existing eco-unfriendly conventional plastics prompted the exploration of natural polymers such as starch for the development of biodegradable plastics. These efforts have seen starch used in various ways, one of which is in the processing of thermoplastic starch (TPS). Thermoplastic starch (also known as plasticized starch) is the product of the interaction between starch and a plasticizer in the presence of thermomechanical energy. While starch blends with conventional plastics only yield products that biofragment, thermoplastic starch (TPS) offers a completely biodegradable option. However, it is limited in application due to its weak mechanical strength and poor moisture resistance. To this end, the objective of this study was to determine the effects of incorporating polycaprolactone (PCL) and flax fiber into glycerol-plasticized pea starch. The effects of processing moisture content on the physical properties of glycerol-plasticized pea starch were also evaluated. The physical properties investigated included morphology, tensile properties, moisture absorption, and thermal properties.<p> Accordingly, two thermoplastic pea starch mixtures containing 9.3 and 20% processing moisture contents were prepared while maintaining starch (pea starch) and glycerol in ratio 7:3 by weight (dry basis). Polycaprolactone was then compounded at 0, 10, 20, 30, and 40% by weight in the solid phase with the TPS mixtures to determine the effects of processing moisture content and PCL incorporation on the physical properties of glycerol-plasticized pea starch. This experiment was structured as a 2 x 5 factorial completely randomized design at 5% level of significance. Subsequently, PCL and flax fiber were compounded with the TPS mixture containing 20% processing moisture to determine the effects of PCL (0, 20, and 40% wt) and flax fiber (0, 5, 10, and 15% wt) incorporation on the physical properties of glycerol-plasticized pea starch. This was structured as a 3 x 4 factorial completely randomized design at 5% level of significance. All the samples were compressed at 140°C for 45 min under 25000-kg load. The compression-molded samples were characterized using scanning electron microscopy (SEM), tensile test, moisture absorption test, and differential scanning calorimetry (DSC) techniques.<p> The tensile fracture surfaces showed a moisture-induced fundamental morphological difference between the two TPSs. The TPS prepared at 20% processing moisture content revealed complete starch gelatinization, thus, exhibiting a rather continuous phase whereas the TPS prepared at 9.3% processing moisture content revealed instances of ungelatinized and partly gelatinized pea starch granules. Consequently, the tensile strength, yield strength, Youngs modulus, and elongation at break increased by 208.6, 602.6, 208.5, and 292.0%, respectively at 20% processing moisture content. The incorporation of PCL reduced the degree of starch gelatinization by interfering with moisture migration during compression molding due to its (PCL) hydrophobicity. At both processing moisture levels of 9.3 and 20%, PCL incorporation had significant impacts on the tensile properties of the plasticized pea starch. Flax fiber incorporation also increased the tensile strength, yield strength, and Youngs modulus while concomitantly reducing the elongation at break of the plasticized pea starch. In the TPS/PCL/flax fiber ternary composites, both PCL and flax fiber improved the tensile strength by acting as independent reinforcing materials as no PCL-fiber interfacial bonding was observed. Maximum tensile strength of 11.55 MPa was reached at 10% flax fiber and 40% PCL reinforcement. While the PCL-TPS interfacial interaction was poor, some degree of TPS-flax fiber interfacial bonding was noticed due to their chemical similarity.<p> TPS prepared at 20% moisture showed more moisture affinity than that prepared at 9.3% moisture. The moisture absorption of TPS dropped progressively with the addition of hydrophobic PCL. Fiber incorporation also reduced moisture absorption by the plasticized pea starch. PCL-fiber incorporation also yielded improved moisture resistance vis-à-vis pure TPS. Finally, the TPS processed at 9.3% moisture exhibited higher thermal stability than that processed at 20%. Individual components of the composites retained their respective thermal properties, thus, implying thermodynamic immiscibility.

The effect of fractionating flax, peas and canola on the digestibility of these ingredients in <i>Nile tilapia</i> was determined. Dehulling of flax, and processing peas and canola to pea protein concentrate and canola protein concentrate, resulted in significant increases in the energy and dry matter digestibilities of these products (P < 0.05). Protein digestibility was significantly improved by dehulling flax but there were no differences in the protein digestibilities of pea, canola and their protein concentrates. The ability of the most digestible ingredients from Experiment 1 to replace fish meal in tilapia diets was examined in a 9 week growth trial. The diet formulations were arranged in a 2 x 4 factorial design with 2 types of plant protein mixtures used to replace fish meal (simple: soyabean meal and maize gluten meal or complex: soyabean meal, maize gluten meal, dehulled flax, pea protein concentrate and canola protein concentrate) and 4 levels of protein originating from fish meal (100%, 67%, 33% and 0%). Diets were formulated to contain equal digestible protein (380 g kg-1) and digestible energy (17.63 MJ kg-1). Fifty six tanks containing 10 male <i>Nile tilapia</i> were used in this experiment. Fish were fed to apparent satiation twice daily for a total of 63 days and growth and feed intake was measured for the entire experimental period. On day 64 of the experiment, one fish per tank was euthanized and a 1 cm segment of small intestine was prepared for measurement of villus length. The average daily gains, specific growth rates and feed efficiencies of fish fed diets with 0% fish meal were significantly lower than fish fed diets with the 33, 67 or 100% fish meal levels. Fish fed the complex diets had significantly higher average daily gains, specific growth rates, feed:gain ratios and protein efficiency ratios than those fed the simple diets. Villus length decreased with decreasing levels of fish meal and increased with increased diet complexity but the effects were not significant. The results indicated that replacement of fish meal with a complex mixture of plant ingredients may allow a greater replacement of fish meal in diets fed to <i> Nile tilapia</i>.

The environmental menace associated with the existing eco-unfriendly conventional plastics prompted the exploration of natural polymers such as starch for the development of biodegradable plastics. These efforts have seen starch used in various ways, one of which is in the processing of thermoplastic starch (TPS). Thermoplastic starch (also known as plasticized starch) is the product of the interaction between starch and a plasticizer in the presence of thermomechanical energy. While starch blends with conventional plastics only yield products that biofragment, thermoplastic starch (TPS) offers a completely biodegradable option. However, it is limited in application due to its weak mechanical strength and poor moisture resistance. To this end, the objective of this study was to determine the effects of incorporating polycaprolactone (PCL) and flax fiber into glycerol-plasticized pea starch. The effects of processing moisture content on the physical properties of glycerol-plasticized pea starch were also evaluated. The physical properties investigated included morphology, tensile properties, moisture absorption, and thermal properties.<p> Accordingly, two thermoplastic pea starch mixtures containing 9.3 and 20% processing moisture contents were prepared while maintaining starch (pea starch) and glycerol in ratio 7:3 by weight (dry basis). Polycaprolactone was then compounded at 0, 10, 20, 30, and 40% by weight in the solid phase with the TPS mixtures to determine the effects of processing moisture content and PCL incorporation on the physical properties of glycerol-plasticized pea starch. This experiment was structured as a 2 x 5 factorial completely randomized design at 5% level of significance. Subsequently, PCL and flax fiber were compounded with the TPS mixture containing 20% processing moisture to determine the effects of PCL (0, 20, and 40% wt) and flax fiber (0, 5, 10, and 15% wt) incorporation on the physical properties of glycerol-plasticized pea starch. This was structured as a 3 x 4 factorial completely randomized design at 5% level of significance. All the samples were compressed at 140°C for 45 min under 25000-kg load. The compression-molded samples were characterized using scanning electron microscopy (SEM), tensile test, moisture absorption test, and differential scanning calorimetry (DSC) techniques.<p> The tensile fracture surfaces showed a moisture-induced fundamental morphological difference between the two TPSs. The TPS prepared at 20% processing moisture content revealed complete starch gelatinization, thus, exhibiting a rather continuous phase whereas the TPS prepared at 9.3% processing moisture content revealed instances of ungelatinized and partly gelatinized pea starch granules. Consequently, the tensile strength, yield strength, Youngs modulus, and elongation at break increased by 208.6, 602.6, 208.5, and 292.0%, respectively at 20% processing moisture content. The incorporation of PCL reduced the degree of starch gelatinization by interfering with moisture migration during compression molding due to its (PCL) hydrophobicity. At both processing moisture levels of 9.3 and 20%, PCL incorporation had significant impacts on the tensile properties of the plasticized pea starch. Flax fiber incorporation also increased the tensile strength, yield strength, and Youngs modulus while concomitantly reducing the elongation at break of the plasticized pea starch. In the TPS/PCL/flax fiber ternary composites, both PCL and flax fiber improved the tensile strength by acting as independent reinforcing materials as no PCL-fiber interfacial bonding was observed. Maximum tensile strength of 11.55 MPa was reached at 10% flax fiber and 40% PCL reinforcement. While the PCL-TPS interfacial interaction was poor, some degree of TPS-flax fiber interfacial bonding was noticed due to their chemical similarity.<p> TPS prepared at 20% moisture showed more moisture affinity than that prepared at 9.3% moisture. The moisture absorption of TPS dropped progressively with the addition of hydrophobic PCL. Fiber incorporation also reduced moisture absorption by the plasticized pea starch. PCL-fiber incorporation also yielded improved moisture resistance vis-à-vis pure TPS. Finally, the TPS processed at 9.3% moisture exhibited higher thermal stability than that processed at 20%. Individual components of the composites retained their respective thermal properties, thus, implying thermodynamic immiscibility.

Flax fiber-reinforced plastic composites have attracted increasing interest because of the advantages of flax fibers, such as low density, relatively high toughness, high strength and stiffness, and biodegradability. Thus, oilseed flax fiber derived from flax straw, a renewable resource available in Western Canada, is recognized as a potential replacement for glass fiber in composites. Among plastics, polyethylene is a suitable material for use as a matrix in composites. However, there are not many studies in this area. Therefore, the main goal of this research was to develop flax fiber-polyethylene (PE) biocomposites via injection molding and investigate the effect of material properties and processing parameters on their properties. <p>Alkali, silane, potassium permanganate, sodium chlorite, and acrylic acid treatments were employed to flax fiber to decrease the hydrophilic of fiber and improve the adhesion between the fiber and the matrix. All chemically treated fiber-HDPE biocomposites had higher tensile strength and lower water absorption compared with non-chemically treated ones. Acrylic acid treatment of the fiber resulted in slight increase in its degradation temperature; using this treated fiber resulted in biocomposites with the best performance. Therefore, the morphological, chemical, and thermal properties of acrylic acid treated fiber were also studied. <p>Linear Low Density Polyethylene (LLDPE) and High Density Polyethylene (HDPE) were the main matrices investigated in this research. Showing a high tensile strength and similar water absorption, HDPE was used as the matrix in further research. Flax fiber with 98-99% purity was chosen as reinforcement since the flax shive mixed with the fiber decreased the tensile and flexural properties but increased the water absorption of the biocomposite. <p>Acrylic acid-treated fiber-HDPE biocomposites had been developed through injection molding under different processing conditions. Increasing the fiber content of biocomposite increased its tensile and flexural strengths, especially flexural modulus, but its water absorption capacity also increased. It was possible to improve the mechanical properties of biocomposites and decrease the water absorption by adjusting injection temperature and pressure. Injection temperature had more influence on the quality of the biocomposite than injection pressure. Injection temperature lower than 195°C was recommended to achieve good composite quality. <p>Melts of HDPE and flax fiber-HDPE biocomposites were categorized as power-law fluids. Apparent viscosity, consistency coefficient, and flow behavior index of biocomposites were determined to study their flow behavior. The statistical relationship of these parameters with temperature and fiber content were modeled using the SAS and SPSS softwares. The injection filling time was related to the material rheological properties: biocomposites required longer filling time than pure HDPE. Low injection temperature also resulted in long filling time.<p>The thermal conductivity, thermal diffusivity, and specific heat of biocomposites containing 10, 20, and 30% fiber by mass were determined in the processing temperature range of 170 to 200°C. Fiber content showed a significant influence on the thermal properties of the biocomposites. The predicted minimum cooling time increased with the thickness of the molded material, mold temperature, and injection temperature, but it decreased with the ejection temperature.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Food Science." Includes bibliographical references (p. 165-170).