School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemAn investigation of environmental conditions experienced during the life of high value wood components and products( 2004)The purpose of this project was to collate data on Australian wood products' exports as well as the environmental conditions that these products are exposed to during manufacture, transportation and service. These data are essential for understanding the potential for wood components to `move' in response to periods of drier or more humid conditions than those at the time of manufacture. The knowledge generated will contribute to a subsequent project, whereby a user-friendly tool will be developed to enable for the design and production of appropriate components, joints, adhesives, coatings, and packaging systems that will ensure superior performance of Australian wood products throughout a wide range of climatic conditions. Wood, a hygroscopic material, will undergo changing moisture contents, fluctuating with changes in atmospheric conditions. As a consequence of these changes in moisture content, wood will swell or shrink. For high-value products, these changes can be detrimental to the utility of the product, for example panels can warp, drawers and doors can jam, and glued components can delaminate. Despite the common occurrence of product degrade or failure due to exposure to changing atmospheric conditions, very little effort has been undertaken to quantify the range of expected conditions for Australian exports. Australian forest industries have a long history of export trade in a wide range of products, from woodchips and sandalwood, through to high-value manufactured commodities such as outdoor furniture and assorted flooring products. Current export markets for high-value wood products were found to be predominantly northern hemisphere countries, including United States of America, China (including Hong Kong), Korea, Japan, Europe (including the United Kingdom) and the Middle East. Other regions importing Australian high-value wood products were south-east Asia (Philippines, Indonesia, Thailand and Malaysia), New Zealand and South Africa. A survey was undertaken to determine the range of value-added products currently exported, and it was found that high volumes of flooring, decking, outdoor furniture and kiln-dried boards for furniture and pre-finished flooring products account for the majority of our value-added export effort. There are currently only minor volumes of assembled indoor furniture suites exported from Australia. Wood fibre panels such as plywood, particleboard and medium density fibreboard were outside the scope of this project due to the in-built stability of these products and only solid wood products were considered. Data generated from the survey included the range of timber species used in the manufacture of export products, sawn orientation and typical section sizes used in components. Results from this work showed that the major timbers are: the ash-type eucalypts from south-eastern Australia; jarrah from Western Australia; spotted gum, hoop pine, white cypress, imported kwila, blackbutt, brush box and Sydney blue gum from New South Wales and Queensland. Environmental conditions, especially the combined effect of temperature and relative humidity in microclimates as determined during this research project, can fluctuate extensively during transport from one location to the next. Equilibrium moisture contents (EMC) as low as 5% and as high as 20% were experienced during the shipping of wood products. In addition, the conditions at the place of manufacture (often 10 to 12% EMC) may be vastly different to the environment where the wood products are ultimately placed in service. The in-service conditions for many of our export destinations are between 6 to 9% EMC. This range of conditions, from manufacturing through transportation and in-service, can potentially create problems, due to wood components swelling and/or shrinking corresponding with periods of higher and/or lower temperatures and humidities. Packaging systems incorporating plastic and cardboard were shown to offer some protection against humidity changes. For the Australian wood-manufacturing sector to achieve and maintain a reputation for superior high-performance products in overseas markets, designers and manufacturers will require a clear understanding of the potential effects of changing environmental conditions on their products. When the range of conditions anticipated throughout the service life of an item is combined with data for timber stability, a manufacturer can allow for movement in the design of the item. An understanding of effective packaging systems is also necessary to ensure maintenance of timber moisture content during transportation. The research highlighted the inherent risks of exporting high-value wood products to distant markets and the need for development of a user-friendly tool, which would allow manufacturers to determine appropriate design parameters such as species, dimensions, jointing systems, adhesives, coatings and packaging for export products.
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ItemAgricultural and related education : past, present and future( 1998)Research funders, providers, educators and agricultural producers were surveyed to obtain their views on the future directions and needs of agricultural and related education. Information was gathered concerning the missions, challenges and likely major changes facing universities and state government agencies associated with agriculture over the next decade. An overriding focus on issues of environmental management and sustainability was evident in answers with a need for closer interaction between providers of education and research and users of knowledge, particularly agricultural producers. The need to attract high performing and motivated students to fields servicing agriculture was highlighted in the stakeholder survey as well as the literature review, and formed part of a second survey. This survey was conducted to assess the knowledge and perceptions of students' concerning agriculture and the various careers available in agricultural and environmental fields. Year 10 Victorian students from both metropolitan and non-metropolitan regions were surveyed as it was considered that they were at the stage of making first subject choices towards future career paths. A review of changes occurring in the land grant colleges of the United States and similar institutions in Scotland indicated concerns in similar areas. It was concluded that, in common with the United States, existing provision of educational services is failing to meet current expectations of producers in terms of their need for information, creation of learning environments and involvement in decision making of educational providers. It was also noted that the development of an education/research provider partnership with industry was seen as a logical outcome of current debates by some persons from each of the employment categories surveyed. The student survey showed that a greater number of non-metropolitan students had considered a career in agriculture than metropolitan students. It was also found that the most important influence on student knowledge about agricultural careers came from parents, school, and the media; that overall student knowledge of the various careers available to graduates of agricultural science was limited, and where such knowledge existed, it was biased by misconceptions of the role and activities of agricultural scientists. Furthermore students placed great importance on high paying careers, yet did not consider careers in agriculture to be high paying. It was therefore determined that more work needs to be conducted to increase the profile of the variety and activities involved in careers available in agricultural and related areas. The two surveys indicated need for change in Australian agricultural and related education, in similar directions to changes being debated in the United States and elsewhere. This was found in particular with respect to a stronger natural resource management or an environmental approach to agriculture and related education, and enhanced information exchange between industry, and agricultural education and prospective students.
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