Effects of pH on pretreatment of sugarcane bagasse using aqueous imidazolium ionic liquids

Pretreatments of sugarcane bagasse for saccharification using different acid-catalysed imidazolium IL solutions (containing 20% water) at 130 °C for 30 min were investigated. At the same solution pH, pretreatment effectiveness in terms of glucan digestibility, delignification and xylan removal were similar for aqueous 1-butyl-3-methylimidazolium methane sulfonate (BMIMCH3SO3), 1-butyl-3-methylimidazolium methyl sulfate (BMIMCH3SO4), 1-ethyl-3-methylimidazolium chloride (EMIMCl) and 1-butyl-3-methylimidazolium chloride (BMIMCl). Decreasing solution pH of aqueous IL systems from 6.0 to 0.4 increased bagasse delignification and xylan removal, and as a result, improved glucan digestibility. The glucan digestibilities for bagasse samples pretreated by IL solutions with pH ≤ 0.9 were > 90% after 72 h of enzymatic hydrolysis. Without pH adjustment, the effectiveness of these aqueous IL solutions (except BMIMCH3SO3 because of its low natural pH of 0.9) to deconstruct the biomass was poor and the glucan digestibilities of pretreated bagasse samples were < 20%. These results show that pretreatment effectiveness of aqueous imidazolium ILs can simply be estimated from solution pH rather than hydrogen bond basicity (β) of the IL solution.

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.

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.

Perceptions and expectations for learning and development for older workers within Queensland local government councils : a case study

Current literature warns organisations about a global ageing phenomenon. Workplace ageing is causing a diminishing work pool which has consequences for a sustainable workforce in the future. This phenomenon continues to impact on local government councils in Australia. Australia has one of the world’s most rapidly ageing populations, and there is evidence that Australian local government councils are already resulting in an unsustainable workforce. Consequently, this research program investigated the role of older workers in the Queensland local government workplace in enabling them to extend their working lives towards transitional employment and a sustainable workforce in the future. Transitional Employment is intended as a strategy for enabling individuals to have greater control over their employment options and their employability during the period leading to their final exit from the workforce. There was no evidence of corporate support for older workers in Queensland local government councils other than tokenistic government campaigns encouraging organisations to "better value their older workers". (Queensland Government, 2007d, p.6). TE is investigated as a possible intervention for older workers in the future. The international and national literature review reflected a range of matters impacting on current older workers in the workforce and barriers preventing them from accessing services towards extending their employment beyond the traditional retirement age (60 years) as defined by the Australian Government; an age when individuals can access their superannuation. Learning and development services were identified as one of those barriers. There was little evidence of investment in or consistent approaches to supporting older workers by organisations. Learning and development services appeared at best to be ad hoc, reactive to corporate productivity and outputs with little recognition of the ageing phenomenon (OECD, 2006, p.23) and looming skills and labour shortages (ALGA, 2006, p. 19). Themes from the literature review led to the establishment of three key research questions: 1. What are the current local government workforce issues impacting on skills and labour retention? 2. What are perceptions about the current workplace environment? And, 3. What are the expectations about learning and development towards extending employability of older workers within the local government sector? The research questions were explored by utilising three qualitative empirical studies, using some numerical data for reporting and comparative analysis. Empirical Study One investigated common themes for accessing transitional employment and comprised two phases. A literature review and Study One data analysis enabled the construction of an initial Transitional Employment Model which includes most frequent themes. Empirical Study Two comprised focus groups to further consider those themes. This led to identification of issues impacting the most on access to learning and development by older workers and towards a revised TEM. Findings presented majority support for transitional employment as a strategy for supporting older workers to work beyond their traditional retirement age. Those findings are presented as significant issues impacting on access to transitional employment within the final 3-dimensionsal TEM. The model is intended as a guide for responding to an ageing workforce by local government councils in the future. This study argued for increased and improved corporate support, particularly for learning and development services for older workers. Such support will enable older workers to maintain their employability and extend their working lives; a sustainable workforce in the future.

Effect of pretreatment on saccharification of sugarcane bagasse by complex and simple enzyme mixtures

Saccharification of sugarcane bagasse pretreated at the pilot-scale with different processes (in combination with steam-explosion) was evaluated. Maximum glucan conversion with Celluclast 1.5 L (15–25 FPU/g glucan) was in the following order: glycerol/HCl > HCl > H2SO4 > NaOH, with the glycerol system achieving ∼100% conversion. Surprisingly, the NaOH substrate achieved optimum saccharification with only 8 FPU/g glucan. Glucan conversions (3.6–6%) obtained with mixtures of endo-1,4-β-glucanase (EG) and β-glucosidase (βG) for the NaOH substrate were 2–6 times that of acid substrates. However, glucan conversions (15–60%) obtained with mixtures of cellobiohydrolase (CBH I) and βG on acidified glycerol substrate were 10–30% higher than those obtained for NaOH and acid substrates. The susceptibility of the substrates to enzymatic saccharification was explained by their physical and chemical attributes. Acidified glycerol pretreatment offers the opportunity to simplify the complexity of enzyme mixtures required for saccharification of lignocellulosics.

Outdoor worker sun protection project : a comprehensive applied research project to demonstrate the effectiveness of sun protection measures which influence high risk outdoor workers in Queensland to adopt sun safe behaviour practices 2010 – 2013

The QUT Outdoor Worker Sun Protection (OWSP) project undertook a comprehensive applied health promotion project to demonstrate the effectiveness of sun protection measures which influence high risk outdoor workers in Queensland to adopt sun safe behaviours. The three year project (2010-2013) was driven by two key concepts: 1) The hierarchy of control, which is used to address risks in the workplace, advocates for six control measures that need to be considered in order of priority (refer to Section 3.4.2); and 2) the Ottawa Charter which recommends five action means to achieve health promotion (refer to Section 2.1). The project framework was underpinned by a participatory action research approach that valued peoples’ input, took advantage of existing skills and resources, and stimulated innovation (refer to Section 4.2). Fourteen workplaces (small and large) with a majority outdoor workforce were recruited across regional Queensland (Darling Downs, Northwest, Mackay and Cairns) from four industries types: 1) building and construction, 2) rural and farming, 3) local government, and 4) public sector. A workplace champion was identified at each workplace and was supported (through resource provision, regular contact and site visits) over a 14 to 18 month intervention period to make sun safety a priority in their workplace. Employees and employers were independently assessed for pre- and postintervention sun protection behaviours. As part of the intervention, an individualised sun safety action plan was developed in conjunction with each workplace to guide changes across six key strategy areas including: 1) Policy (e.g., adopt sun safety practices during all company events); 2) Structural and environmental (e.g., shade on worksites; eliminate or minimise reflective surfaces); 3) Personal protective equipment (PPE) (e.g., trial different types of sunscreens, or wide-brimmed hats); 4) Education and awareness (e.g., include sun safety in inductions and toolbox talks; send reminder emails or text messages to workers);5) Role modelling (e.g., by managers, supervisors, workplace champions and mentors); and 6) Skin examinations (e.g., allow time off work for skin checks). The participatory action process revealed that there was no “one size fits all” approach to sun safety in the workplace; a comprehensive, tailored approach was fundamental. This included providing workplaces with information, resources, skills, know how, incentives and practical help. For example, workplaces engaged in farming complete differing seasonal tasks across the year and needed to prepare for optimal sun safety of their workers during less labour intensive times. In some construction workplaces, long pants were considered a trip hazard and could not be used as part of a PPE strategy. Culture change was difficult to achieve and workplace champions needed guidance on the steps to facilitate this (e.g., influencing leaders through peer support, mentoring and role modelling). With the assistance of the project team the majority of workplaces were able to successfully implement the sun safety strategies contained within their action plans, up skilling them in the evidence for sun safety, how to overcome barriers, how to negotiate with all relevant parties and assess success. The most important enablers to the implementation of a successful action plan were a pro-active workplace champion, strong employee engagement, supportive management, the use of highly visual educational resources, and external support (provided by the project team through regular contact either directly through phone calls or indirectly through emails and e-newsletters). Identified barriers included a lack of time, the multiple roles of workplace champions, (especially among smaller workplaces), competing issues leading to a lack of priority for sun safety, the culture of outdoor workers, and costs or budgeting constraints. The level of sun safety awareness, knowledge, and sun protective behaviours reported by the workers increased between pre-and post-intervention. Of the nine sun protective behaviours that were assessed, the largest changes reported included a 26% increase in workers who “usually or always” wore a broad-brimmed hat, a 20% increase in the use of natural shade, a 19% increase in workers wearing long-sleeved collared shirts, and a 16% increase in workers wearing long trousers.

Outdoor Worker Sun Protection Project : a mixed methods intervention to improve sun safety among outdoor workers

Queensland, Australia has one of the highest rates of skin cancer in the world. Outdoor workers are regularly exposed to high doses of ultraviolet radiation, and are at increased risk to develop non-melanoma and melanoma skin cancers. In 2010, a health promotion intervention to improve sun protection among outdoor workers in Queensland commenced. The intervention employed a mixed methods approach and a participatory action research framework. Fourteen workplaces were recruited from building and construction, rural and farming, local government, and public sector organisations. Management and workers were engaged in cycles of assessment, reflection and discussion, planning, implementation and reassessing, over a 14-month intervention period. Overall, at least one workplace representative from each workplace (range 1-3) and in depth focus groups were held with a subset of workers (range 3-16) to assess sun safe behaviours pre and post intervention. Workers’ attitudes, beliefs, knowledge and willingness to engage in sun protection differed depending on workplace characteristics and support. A familiar theme among workers spoke of sun safety as being “common sense” and the “workers individual responsibility”. Often there was a discrepancy in the perceptions of the workers, compared to the view of workplace representatives and the workplaces position or policy on sun safety. In larger workplaces, especially Government Departments, workers were more aware and followed sun safe practices compared to smaller workplaces where sun safety was not a high priority. These results indicate that a workplace culture which places high values on safety and polices more broadly may also have a positive effect on sun safety among outdoor workers as well. In addition, the specific characteristics of the workplace and the outdoor work tasks influence workers willingness to engage in sun safety measures.

Implementation and removal of an affirmative-action quota : the impact on task assignment and workers’ skill acquisition

Both the United States and Canada have federal legislation that attempts to address employment inequities across specific target groups. The US has a long tradition of affirmative action, dating back to President Kennedy’s 1961 Executive Order; Canada enacted its Employment Equity Act in 1986. Employment Equity/Affirmative Action policy has attracted significant controversy, with high profile court cases and the repeal of state/provincial legislation. Coate and Loury (1993) examine the theoretical impact of introducing affirmative action. Unfortunately the theoretical impact of affirmative action is ambiguous. The current paper employs a laboratory experiment to shed empirical light on this theoretical ambiguity.

Stitching at the boundaries : Vietnamese garment industry workers in transnational spaces

This paper explores the interfaces between the transnational politics of labour and the experiences of Vietnamese women garment workers both in Vietnam and as migrants to other countries. As the global industries have come to organise much of the contemporary economic system, so too have they crossed national boundaries in search of cheap labour. At the same time enclaves of migrant disadvantage within the multi-ethnic nation-states of the developed world have also provided workers for the manufacture of clothing. In the case of Australia, these workers are mostly home-based and not in factories. In this paper I explore Vietnamese women's different incorporations into the garment industry in various locations – in Australia, in Vietnam, and in American Samoa. In so doing, I provide an analysis of the links between gender, global power relations and the contradictory space of transnational exchange.

Low temperature pretreatment of sugarcane bagasse at atmospheric pressure using mixtures of ethylene carbonate and ethylene glycol

A low temperature lignocellulose pretreatment process was developed using acid-catalysed mixtures of alkylene carbonate and alkylene glycol. Pretreatment of sugarcane bagasse with mixtures of ethylene carbonate (EC) and ethylene glycol (EG) was more effective than that with mixtures of propylene carbonate (PC) and propylene glycol (PG). These mixtures were more effective than the individual components in making bagasse cellulose more amenable to cellulase digestion. Glucan digestibilities of ≥87% could be achieved with a wide range of EC to EG ratios from 9:1 to 1:1 (w/w). Pretreatment of bagasse by the EC/EG mixture with a ratio of 4:1 in the presence of 1.2% H2SO4 at 90 °C for 30 min led to the highest glucan enzymatic digestibility of 93%. The high glucan digestibilities obtained under these acidic conditions were due to (a) the ability of alkylene carbonate to cause significant biomass size reduction, (b) the ability of alkylene glycol to cause biomass defibrillation, (c) the ability of alkylene carbonate and alkylene glycol to remove xylan and lignin, and (d) the magnified above attributes in the mixtures of alkylene carbonate and alkylene glycol.

Residential care workers and residents : the New Zealand story

Aims To describe the nature and size of long-term residential care homes in New Zealand; funding of facilities; and the ethnic and gender composition of residents and residential care workers nationwide. Methods A postal, fax, and email survey of all long-term residential care homes in New Zealand. Results Completed surveys were received from an eligible 845 facilities (response rate: 55%). The majority of these (54%) facilities housed less than 30 residents. Of the 438 (94%) facilities completing the questions about residents’ ethnicity, 432 (99%) housed residents from New Zealand European (Pakeha) descent, 156 (33%) housed at least 1 Maori resident, 71 (15%) at least 1 Pacific (Islands) resident, and 61 (13%) housed at least 1 Asian resident. Facilities employed a range of ethnically diverse staff, with 66% reporting Maori staff. Less than half of all facilities employed Pacific staff (43%) and Asian staff (33%). Registered nursing staff were mainly between 46 and 60 years (47%), and healthcare assistant staff were mostly between 25 and 45 years old (52%). Wide regional variation in the ethnic make up of staff was reported. About half of all staff were reported to have moved within the previous 2 years. Conclusions The age and turnover of the residential care workforce suggests the industry continues to be under threat from staffing shortages. While few ethnic minority residents live in long-term care facilities, staff come from diverse backgrounds, especially in certain regions.

Understanding mild acid pretreatment of sugarcane bagasse through particle scale modeling

Sugarcane bagasse is an abundant and sustainable resource, generated as a by-product of sugarcane milling. The cellulosic material within bagasse can be broken down into glucose molecules and fermented to produce ethanol, making it a promising feedstock for biofuel production. Mild acid pretreatment hydrolyses the hemicellulosic component of biomass, thus allowing enzymes greater access to the cellulosic substrate during saccharification. A particle-scale mathematical model describing the mild acid pretreatment of sugarcane bagasse has been developed, using a volume averaged framework. Discrete population-balance equations are used to characterise the polymer degradation kinetics, and diffusive effects account for mass transport within the cell wall of the bagasse. As the fibrous material hydrolyses over time, variations in the porosity of the cell wall and the downstream effects on the reaction kinetics are accounted for using conservation of volume arguments. Non-dimensionalization of the model equations reduces the number of parameters in the system to a set of four dimensionless ratios that compare the timescales of different reaction and diffusion events. Theoretical yield curves are compared to macroscopic experimental observations from the literature and inferences are made as to constraints on these “unknown” parameters. These results enable connections to be made between experimental data and the underlying thermodynamics of acid pretreatment. Consequently, the results suggest that data-fitting techniques used to obtain kinetic parameters should be carefully applied, with prudent consideration given to the chemical and physiological processes being modeled.

Rapid nutrient determination of sugarcane milling by-products using near infrared spectroscopy

This thesis investigates the use of near infrared (NIR) spectroscopic methods for rapid measurement of nutrient elements in mill mud and mill ash. Adoption of NIR-based analyses for carbon, nitrogen, phosphorus, potassium and silicon will allow Australian sugarcane farmers to comply with recent legislative changes, and act within recommended precision farming frameworks. For these analyses, NIR spectroscopic methods surpass several facets of traditional wet chemistry techniques, dramatically reducing costs, required expertise and chemical exposure, while increasing throughput and access to data. Further, this technology can be applied in various modes, including laboratory, at-line and on-line installations, allowing targeted measurement.

Risk compensation in construction workers' activities

Construction has been plagued with serious injuries and deaths for years. Although the technological advances have made the world safer and healthier, researchers have noted that some safety interventions, which had clear objective safety benefits, had failed to achieve the forecast savings in lives and injuries. The purpose of this study was to explore whether the construction workers show risk compensation and engage in greater risk taking when certain types of safety measures are implemented in the construction site. A case study approach was used to achieve the aim of this study. A typical construction site in Sydney was selected as the subject of the case study. Data were collected through direct observations, questionnaires and interviews. The findings confirm that workers show risk compensation behaviours in the construction environment. The risk compensation behaviours of workers varied with the level of experience and whether they have suffered from a past workplace injury. The findings of this study may offer a better understanding of workers’ behavioural patterns in construction environment and the effectiveness of safety interventions. The result of this study may provide supports for designing, implementing and evaluating safety interventions in construction site.