Developing schedules for mixed rail and road cane transport systems

This paper addresses the problem of scheduling a cane transport system involving both rail transport and road transport, where the road transport operates from several sidings in the rail network. An iterative approach for scheduling the rail transport system has been developed using existing rail transport scheduling tools. The assumption that harvesters serviced by road transport are effectively operating from the rail siding from which their bins are supplied seems a reasonable starting point for the analysis. There is a need to manually modify the schedule to take into account the road transport schedule to ensure that full bins are not collected before the road transport system delivers them back to the rail siding.

Food policy, dietary intakes and chronic disease in prisons

International research on prisoners demonstrates poor health outcomes, including chronic disease, with the overall burden to the community high. Prisoners are predominantly male and young. In Australia, the average incarceration length is 3 years, sufficient to impact long term health, including nutrition. Food in prisons is highly controlled, yet gaps exist in policy. In most Western countries prisons promote healthy foods, often incongruent with prisoner expectations or wants. Few studies have been conducted on dietary intakes during incarceration in relation to food policy. In this study detailed diet histories were collected on 120/945 men (mean age = 32 years), in a high-secure prison. Intakes were verified via individual purchase records, mealtime observations, and audits of food preparation, purchasing and holdings. Physical measurements (including fasting bloods) were taken and medical records reviewed. Results showed the standard food provided consistent with current dietary guidelines, however limited in menu choice. Diet histories revealed self-funded foods contributing 1–63% of energy (mean = 30%), 0–83% sugar (mean = 38%), 1–77% saturated fats (mean = 31%) and 1–59% sodium (mean = 23%). High levels of modification to food provided was found using minimal cooking amenities and inclusion of self-funded foods and/or foods retained from previous meals. Medical records and physical measurements confirmed markers of chronic disease. This study highlights the need to establish clear guidelines on all food available in prisons if chronic disease risk reduction is a goal. This study has also supported evidenced based food and nutrition policy including menu choice, food quality, quantity and safety as well as type and access to self-funded foods.

Caustic potash pulping study of water efficient Arudno donax and Sorghum bicolor; a comparison to sugarcane bagasse

Numerous crops grow in sugar regions that have the potential to increase the amount of biomass available to a small bagasse-based pulp factory. Arundo donax and Sorghum offer unique advantages to farmers compared to other agricultural crops. Sorghum bicolour requires only 1/3 of the water of sugarcane. Arundo donax is a very high yield crop, it can also grow with little water but it has the further advantage in that it is also highly stress tolerant, making it suitable for land which is unsuited to other crops. Pulps produced from these crops were benchmarked against sugarcane bagasse pulp. Arundo, sorghum and bagasse were pulped using KOH and anthraquinone to 20 Kappa number so as to produce a bleachable pulp. The unbleached sorghum pulp has better tensile strength properties than the unbleached Arundo pulp (43.8 Nm/g compared to 21.4 Nm/g) and the bleached sorghum pulp tensile strength was similar to bagasse (28.4 Nm/g). At 20 Kappa number, sorghum pulp had acceptable yield for a non-wood fibre (45% c.f. 55% for bagasse), Arundo donax pulp had low tensile strength, and relatively low yield (38.7%), even for an agricultural fibre and required severe cooking conditions to achieve similar delignification to sugarcane bagasse or sorghum. Sorghum and Arundo donax produced thicker handsheets than bagasse (>160 μm c.f. 122 μm for bagasse). In preliminary experiments sorghum and bagasse responded slightly better to Totally Chlorine Free bleaching (QPP), although none achieved a satisfactory brightness level and more optimisation is needed.

Metabolic and ecological study of environmental pentose utilizing bacteria (E-PUB)

Lignocellulosic materials, such as sugar cane bagasse, a waste product of the sugarcane processing industry, agricultural residues and herbaceous crops, may serve as an abundant and comparatively cheap feedstock for largescale industrial fermentation, resulting in the production of marketable end-products. However, the complex structure of lignocellulosic materials, the presence of various hexose and pentose sugars in the hemicellulose component, and the presence of various compounds that inhibit the organisms selected for the fermentation process, all constitute barriers that add to the production costs and make full scale industrial production economically less feasible. The work presented in this thesis was conducted in order to screen microorganisms for ability to utilize pentose sugars derived from the sugar mill industrial waste. A large number of individual bacterial strains were investigated from hemi-cellulose rich material collected at the Proserpine and Maryborough sugar mills, notably soil samples from the mill sites. The research conducted to isolation of six pentose-capable Gram-positive organisms from the actinomycetes group by using pentose as a sole carbon source in the cultivation process. The isolates were identified as Corynebacterium glutamicum, Actinomyces odontolyticus, Nocardia elegans, and Propionibacterium freudenreichii all of which were isolated from the hemicellulose-enriched soil. Pentose degrading microbes are very rare in the environment, so this was a significant discovery. Previous research indicated that microbes could degrade pentose after genetic modification but the microbes discovered in this research were able to naturally utilize pentose. Six isolates, identified as four different genera, were investigated for their ability to utilize single sugars as substrates (glucose, xylose, arabinose or ribose), and also dual sugars as substrates (a hexose plus a pentose). The results demonstrated that C. glutamicum, A. odontolyticus, N. elegans, and P. freudenreichii were pentose-capable (able to grow using xylose or other pentose sugar), and also showed diauxie growth characteristics during the dual-sugar (glucose, in combination with xylose, arabinose or ribose) carbon source tests. In addition, it was shown that the isolates displayed very small differences in growth rates when grown on dual sugars as compared to single sugars, whether pentose or hexose in nature. The anabolic characteristics of C. glutamicum, A. odontolyticus, N. elegans and P. freudenreichii were subsequently investigated by qualitative analysis of their end-products, using high performance liquid chromatography (HPLC). All of the organisms produced arginine and cysteine after utilization of the pentose substrates alone. In addition, P. freudenreichii produced alanine and glycine. The end-product profile arising from culture with dual carbon sources was also tested. Interestingly, this time the product was different. All of them produced the amino acid glycine, when grown on a combination substrate-mix of glucose with xylose, and also glucose with arabinose. Only N. elegans was able to break down ribose, either singly or in combination with glucose, and the end-product of metabolism of the glucose plus ribose substrate combination was glutamic acid. The ecological analysis of microbial abundance in sugar mill waste was performed using denaturing gradient gel electrophoresis (DGGE) and also the metagenomic microarray PhyloChip method. Eleven solid samples and seven liquid samples were investigated. A very complex bacterial ecosystem was demonstrated in the seven liquid samples after testing with the PhyloChip method. It was also shown that bagasse leachate was the most different, compared to all of the other samples, by virtue of its richness in variety of taxa and the complexity of its bacterial community. The bacterial community in solid samples from Proserpine, Mackay and Maryborough sugar mills showed huge diversity. The information found from 16S rDNA sequencing results was that the bacterial genera Brevibacillus, Rhodospirillaceae, Bacillus, Vibrio and Pseudomonas were present in greatest abundance. In addition, Corynebacterium was also found in the soil samples. The metagenomic studies of the sugar mill samples demonstrate two important outcomes: firstly that the bagasse leachate, as potentially the most pentose-rich sample tested, had the most complex and diverse bacterial community; and secondly that the pentose-capable isolates that were initially discovered at the beginning of this study, were not amongst the most abundant taxonomic groups discovered in the sugar mill samples, and in fact were, as suspected, very rare. As a bioprospecting exercise, therefore, the study has discovered organisms that are naturally present, but in very small numbers, in the appropriate natural environment. This has implications for the industrial application of E-PUB, in that a seeding process using a starter culture will be necessary for industrial purposes, rather than simply assuming that natural fermentation might occur.

Engineering the surface of a sugarcane roller mill roll for grip and durability

Roller mills are typically used to crush sugarcane to express the juice from which sugar is manufactured. The mill rolls need to provide sufficient grip to ensure minimal sliding of the sugarcane along the roll surface. The rolls are subject to pressures up to 55 MPa from the sugarcane bagasse (as the sugarcane is called after first being crushed between a pair of rolls). The insoluble component of sugarcane includes typically 10% ash that largely originates from soil that is harvested with the cane. The sugarcane juice is acidic with pH typically between 5.0 and 5.5. As a result of ash and juice, the mill rolls are subjected to a range of abrasive and corrosive wear mechanisms. Solutions to provide grip and resist wear involve the selection of an appropriate roll shell material and compatible hard facing to provide the desired grip and wear characteristics. This paper reviews the various solutions that have been adopted for grip and durability for mill rolls and highlights the advantages and disadvantages of each method.

The contribution of psychosocial factors to socioeconomic differences in food purchasing

In developed countries the relationship between socioeconomic position (SEP) and health is unequivocal. Those who are socioeconomically disadvantaged are known to experience higher morbidity and mortality from a range of chronic diet-related conditions compared to those of higher SEP. Socioeconomic inequalities in diet are well established. Compared to their more advantaged counterparts, those of low SEP are consistently found to consume diets less consistent with dietary guidelines (i.e. higher in fat, salt and sugar and lower in fibre, fruit and vegetables). Although the reasons for dietary inequalities remain unclear, understanding how such differences arise is important for the development of strategies to reduce health inequalities. Both environmental (e.g. proximity of supermarkets, price, and availability of foods) and psychosocial (e.g. taste preference, nutrition knowledge) influences are proposed to account for inequalities in food choices. Although in the United States (US), United Kingdom (UK), and parts of Australia, environmental factors are associated with socioeconomic differences in food choices, these factors do not completely account for the observed inequalities. Internationally, this context has prompted calls for further exploration of the role of psychological and social factors in relation to inequalities in food choices. It is this task that forms the primary goal of this PhD research. In the small body of research examining the contribution of psychosocial factors to inequalities in food choices, studies have focussed on food cost concerns, nutrition knowledge or health concerns. These factors are generally found to be influential. However, since a range of psychosocial factors are known determinants of food choices in the general population, it is likely that a range of factors also contribute to inequalities in food choices. Identification of additional psychosocial factors of relevance to inequalities in food choices would provide new opportunities for health promotion, including the adaption of existing strategies. The methodological features of previous research have also hindered the advancement of knowledge in this area and a lack of qualitative studies has resulted in a dearth of descriptive information on this topic. This PhD investigation extends previous research by assessing a range of psychosocial factors in relation to inequalities in food choices using both quantitative and qualitative techniques. Secondary data analyses were undertaken using data obtained from two Brisbane-based studies, the Brisbane Food Study (N=1003, conducted in 2000), and the Sixty Families Study (N=60, conducted in 1998). Both studies involved main household food purchasers completing an interviewer-administered survey within their own home. Data pertaining to food-purchasing, and psychosocial, socioeconomic and demographic characteristics were collected in each study. The mutual goals of both the qualitative and quantitative phases of this investigation were to assess socioeconomic differences in food purchasing and to identify psychosocial factors relevant to any observed differences. The quantitative methods then additionally considered whether the associations examined differed according to the socioeconomic indicator used (i.e. income or education). The qualitative analyses made a unique contribution to this project by generating detailed descriptions of socioeconomic differences in psychosocial factors. Those with lower levels of income and education were found to make food purchasing choices less consistent with dietary guidelines compared to those of high SEP. The psychosocial factors identified as relevant to food-purchasing inequalities were: taste preferences, health concerns, health beliefs, nutrition knowledge, nutrition concerns, weight concerns, nutrition label use, and several other values and beliefs unique to particular socioeconomic groups. Factors more tenuously or inconsistently related to socioeconomic differences in food purchasing were cost concerns, and perceived adequacy of the family diet. Evidence was displayed in both the quantitative and qualitative analyses to suggest that psychosocial factors contribute to inequalities in food purchasing in a collective manner. The quantitative analyses revealed that considerable overlap in the socioeconomic variation in food purchasing was accounted for by key psychosocial factors of importance, including taste preference, nutrition concerns, nutrition knowledge, and health concerns. Consistent with these findings, the qualitative transcripts demonstrated the interplay between such influential psychosocial factors in determining food-purchasing choices. The qualitative analyses found socioeconomic differences in the prioritisation of psychosocial factors in relation to food choices. This is suggestive of complex cultural factors that distinguish advantaged and disadvantaged groups and result in socioeconomically distinct schemas related to health and food choices. Compared to those of high SEP, those of lower SEP were less likely to indicate that health concerns, nutrition concerns, or food labels influenced food choices, and exhibited lower levels of nutrition knowledge. In the absence of health or nutrition-related concerns, taste preferences tended to dominate the food purchasing choices of those of low SEP. Overall, while cost concerns did not appear to be a main determinant of socioeconomic differences in food purchasing, this factor had a dominant influence on the food choices of some of the most disadvantaged respondents included in this research. The findings of this study have several implications for health promotion. The integrated operation of psychosocial factors on food purchasing inequalities indicates that multiple psychosocial factors may be appropriate to target in health promotion. It also seems possible that the inter-relatedness of psychosocial factors would allow health promotion targeting a single psychosocial factor to have a flow-on affect in terms of altering other influential psychosocial factors. This research also suggests that current mass marketing approaches to health promotion may not be effective across all socioeconomic groups due to differences in the priorities and main factors of influence in food purchasing decisions across groups. In addition to the practical recommendations for health promotion, this investigation, through the critique of previous research, and through the substantive study findings, has highlighted important methodological considerations for future research. Of particular note are the recommendations pertaining to the selection of socioeconomic indicators, measurement of relevant constructs, consideration of confounders, and development of an analytical approach. Addressing inequalities in health has been noted as a main objective by many health authorities and governments internationally. It is envisaged that the substantive and methodological findings of this thesis will make a useful contribution towards this important goal.

Design of an experimental apparatus to analyse bagasse behaviour in a chute

Pressure feeder chutes are pieces of equipment used in sugar cane crushing to increase the amount of cane that can be put through a mill. The continuous pressure feeder was developed with the objective to provide a constant feed of bagasse under pressure to the mouth of the crushing mills. The pressure feeder chute is used in a sugarcane milling unit to transfer bagasse from one set of crushing rolls to a second set of crushing rolls. There have been many pressure feeder chute failures in the past. The pressure feeder chute is quite vulnerable and if the bagasse throughput is blocked at the mill rollers, the pressure build-up in the chute can be enormous, which can ultimately result in failure. The result is substantial damage to the rollers, mill and chute construction, and downtimes of up to 48 hours can be experienced. Part of the problem is that the bagasse behaviour in the pressure feeder chute is not understood well. If the pressure feeder chute behaviour was understood, then the chute geometry design could be modified in order to minimise risk of failure. There are possible avenues for changing pressure feeder chute design and operations with a view to producing more reliable pressure feeder chutes in the future. There have been previous attempts to conduct experimental work to determine the causes of pressure feeder chute failures. There are certain guidelines available, however pressure feeder chute failures continue. Pressure feeder chute behaviour still remains poorly understood. This thesis contains the work carried out between April 14th 2009 and October 10th 2012 that focuses on the design of an experimental apparatus to measure forces and visually observe bagasse behaviour in an attempt to understand bagasse behaviour in pressure feeder chutes and minimise the risk of failure.

An innovative method to obtain porous PLLA scaffolds with highly spherical and interconnected pores

Scaffolding is an essential issue in tissue engineering and scaffolds should answer certain essential criteria: biocompatibility, high porosity, and important pore interconnectivity to facilitate cell migration and fluid diffusion. In this work, a modified solvent castingparticulate leaching out method is presented to produce scaffolds with spherical and interconnected pores. Sugar particles (200–300 lm and 300–500 lm) were poured through a horizontal Meker burner flame and collected below the flame. While crossing the high temperature zone, the particles melted and adopted a spherical shape. Spherical particles were compressed in plastic mold. Then, poly-L-lactic acid solution was cast in the sugar assembly. After solvent evaporation, the sugar was removed by immersing the structure into distilled water for 3 days. The obtained scaffolds presented highly spherical interconnected pores, with interconnection pathways from 10 to 100 lm. Pore interconnection was obtained without any additional step. Compression tests were carried out to evaluate the scaffold mechanical performances. Moreover, rabbit bone marrow mesenchymal stem cells were found to adhere and to proliferate in vitro in the scaffold over 21 days. This technique produced scaffold with highly spherical and interconnected pores without the use of additional organic solvents to leach out the porogen.

Converse consumption : the converse blank canvas project

Research background For almost 80 years the Chuck Taylor (or Chuck T's) All Star basketball shoe has been an iconic item of fashion apparel. The Chuck T's were first designed in 1921 by Converse, an American shoe company and over the decades they became a popular item not purely for sports and athletic purposes but rather evolved into the shoe of choice for many subcultural groups as a fashion item. In some circles the Chuck Taylor is still seen as the "coolest" sneaker of all time - one which will never go out of fashion regardless of changing trends. With over 600 millions pairs sold all over the world since its release, the Converse shoe is representative of not only a fashion culture - but also of a consumption culture - that evolved as the driving force behind the massive growth of the Western economic system during the 20th Century. Artisan Gallery (Brisbane), in conjunction with the exhibition Reboot: Function, Fashion and the Sneaker, a history of the sneaker, selected 20 designers to customise and re-design the classic Converse Chuck Taylor All Stars shoe and in doing so highlighted the diversity of forms possible for creative outcomes. As Artisan Gallery Curator Kirsten Fitzpatrick states “We were expecting people to draw and paint on them. Instead, we had shoes... mounted as trophies.." referring to the presentation of "Converse Consumption". The exhibition ran from 21 June – 16 August 2012: Research question The Chuck T’s is one of many overwhelmingly commercially successful designs of the last century. Nowadays we are faced with the significant problems of overconsumption and the stress this causes on the natural ecosystem; and on people as a result. As an active member of the industrial design fraternity – a discipline that sits at the core of this problem - how can I use this opportunity to comment on the significant issue of consumption? An effective way to do this was to associate consumption of goods with consumption of sugar. There are significant similarities between our ceaseless desires to consume products and our fervent need to consume indulgent sweet foods. Artisan Statement Delicious, scrumptious, delectable... your pupils dilate, your blood pressure spikes, your liver goes into overdrive. Immediately, your brain cuts off the adenosine receptors, preventing drowsiness. Your body increases dopamine production, in-turn stimulating the pleasure receptors in your brain. Your body absorbs all the sweetness and turns it into fat – while all the nutrients that you actually require are starting to be destroyed, about to be expelled. And this is only after one bite! After some time though, your body comes crashing back to earth. You become irritable and begin to feel sluggish. Your eyelids seem heavy while your breathing pattern changes. Your body has consumed all the energy and destroyed all available nutrients. You literally begin to shut down. These are the physiological effects of sugar consumption. A perfect analogy for our modern day consumer driven world. Enjoy your dessert! Research contribution “Converse Consumption” contributes to the conversation regarding over-consumption by compelling people to reflect on their consumption behaviour through the reconceptualising of the deconstructed Chuck T’s in an attractive edible form. By doing so the viewer has to deal with the desire to consume the indulgent looking dessert with the contradictory fact that it is comprised of a pair of shoes. The fact that the shoes are Chuck T’s make the effect even more powerful due to their iconic status. These clashing motivations are what make “Converse Consumption” a bizarre yet memorable experience. Significance The exhibition was viewed by an excess of 1000 people and generated exceptional media coverage and public exposure/impact. As Artisan Gallery Curator Kirsten Fitzpatrick states “20 of Brisbane's best designers were given the opportunity to customise their own Converse Sneakers, with The Converse Blank Canvas Project.” And to be selected in this category demonstrates the calibre of importance for design prominence.