A novel population balance model for the dilute acid hydrolysis of hemicellulose

Acid hydrolysis is a popular pretreatment for removing hemicellulose from lignocelluloses in order to produce a digestible substrate for enzymatic saccharification. In this work, a novel model for the dilute acid hydrolysis of hemicellulose within sugarcane bagasse is presented and calibrated against experimental oligomer profiles. The efficacy of mathematical models as hydrolysis yield predictors and as vehicles for investigating the mechanisms of acid hydrolysis is also examined. Experimental xylose, oligomer (degree of polymerisation 2 to 6) and furfural yield profiles were obtained for bagasse under dilute acid hydrolysis conditions at temperatures ranging from 110C to 170C. Population balance kinetics, diffusion and porosity evolution were incorporated into a mathematical model of the acid hydrolysis of sugarcane bagasse. This model was able to produce a good fit to experimental xylose yield data with only three unknown kinetic parameters ka, kb and kd. However, fitting this same model to an expanded data set of oligomeric and furfural yield profiles did not successfully reproduce the experimental results. It was found that a ``hard-to-hydrolyse'' parameter, $\alpha$, was required in the model to ensure reproducibility of the experimental oligomer profiles at 110C, 125C and 140C. The parameters obtained through the fitting exercises at lower temperatures were able to be used to predict the oligomer profiles at 155C and 170C with promising results. The interpretation of kinetic parameters obtained by fitting a model to only a single set of data may be ambiguous. Although these parameters may correctly reproduce the data, they may not be indicative of the actual rate parameters, unless some care has been taken to ensure that the model describes the true mechanisms of acid hydrolysis. It is possible to challenge the robustness of the model by expanding the experimental data set and hence limiting the parameter space for the fitting parameters. The novel combination of ``hard-to-hydrolyse'' and population balance dynamics in the model presented here appears to stand up to such rigorous fitting constraints.

CultureMap

CultureMap is the mobile app for the Cultural Atlas of Australia, a digital atlas that maps the locations of more than 200 films, novels, and plays that feature Australian spaces and places. You can use the CultureMap app to find narrative and filming locations near you, you can search for your favourite Australian stories to find out where they are set, or you can search by location to discover what stories have been set there. The app also features our Mapping Ecological Themes showcase, which focuses on films and novels that foreground ecological themes or are set in environmentally sensitive areas. CultureMap is co-funded through an Australian Research Council Discovery Grant and an Inspiring Australia: Unlocking Australia’s Potential grant.

Modelling milling train performance

This paper describes recent updates to a milling train extraction model used to assess and predict the performance of a milling train. An extension was made to the milling unit model for the bagasse mills to replace the imbibition coefficient with crushing factor and mixing efficiency. New empirical relationships for reabsorption factor, imbibition coefficient, crushing factor, mixing efficiency and purity ratio were developed. The new empirical relationships were tested against factory measurements and previous model predictions. The updated model has been implemented in the SysCAD process modelling software. New additions to the model implementation include: a shredder model to assess or predict cane preparation, mill and shredder drives for power consumption and an updated imbibition control system to add allow water to be added to intermediate mills.

Investigation of lignin biosynthesis in sugarcane for improved lignocellulosic ethanol production

As oil use increases at a rate unsustainable for the environment and unmatchable by current levels of oil production, a major shift towards renewable energy is necessary. By expanding the current knowledge of lignin biosynthesis and its manipulation in sugarcane, this PhD contributes to the production of economically viable second generation bioethanol, a fuel produced from plant biomass. The findings of this thesis contribute to the limited knowledge of lignin biosynthesis and deposition in sugarcane, and the application of biotechnology to produce sugarcane, and the resulting bagasse, with a modified cell wall. Reducing or modifying the lignin content in the cell wall of bagasse can reduce production costs and increase yields of bioethanol. This makes bioethanol more economically competitive with oil as an alternative energy source. A move to using bioethanol over fossil based transport fuels will have global economic and environmental benefits.

Developing starch-based polymer composites

This project aim was to replace petroleum-based plastic packaging materials that pollute the environment, with biodegradable starch-based polymer composites. It was demonstrated that untreated sugar cane bagasse microfibres and unbleached nanofibres significantly improved the physical, mechanical and chemical properties of starch films, while thermal extrusion of starch with alcohol improved the stiffness and the addition of aconitic acid cross-linked the film making it moisture resistant and extensible.

Media futures: A review essay on'The Future of Reputation','TV Futures', and'The Future of the Internet and How to Stop It'

In his 1987 book, The Media Lab: Inventing the Future at MIT, Stewart Brand provides an insight into the visions of the future of the media in the 1970s and 1980s. 1 He notes that Nicolas Negroponte made a compelling case for the foundation of a media laboratory at MIT with diagrams detailing the convergence of three sectors of the media—the broadcast and motion picture industry; the print and publishing industry; and the computer industry. Stewart Brand commented: ‘If Negroponte was right and communications technologies really are converging, you would look for signs that technological homogenisation was dissolving old boundaries out of existence, and you would expect an explosion of new media where those boundaries used to be’. Two decades later, technology developers, media analysts and lawyers have become excited about the latest phase of media convergence. In 2006, the faddish Time Magazine heralded the arrival of various Web 2.0 social networking services: You can learn more about how Americans live just by looking at the backgrounds of YouTube videos—those rumpled bedrooms and toy‐strewn basement rec rooms—than you could from 1,000 hours of network television. And we didn’t just watch, we also worked. Like crazy. We made Facebook profiles and Second Life avatars and reviewed books at Amazon and recorded podcasts. We blogged about our candidates losing and wrote songs about getting dumped. We camcordered bombing runs and built open‐source software. America loves its solitary geniuses—its Einsteins, its Edisons, its Jobses—but those lonely dreamers may have to learn to play with others. Car companies are running open design contests. Reuters is carrying blog postings alongside its regular news feed. Microsoft is working overtime to fend off user‐created Linux. We’re looking at an explosion of productivity and innovation, and it’s just getting started, as millions of minds that would otherwise have drowned in obscurity get backhauled into the global intellectual economy. The magazine announced that Time’s Person of the Year was ‘You’, the everyman and everywoman consumer ‘for seizing the reins of the global media, for founding and framing the new digital democracy, for working for nothing and beating the pros at their own game’. This review essay considers three recent books, which have explored the legal dimensions of new media. In contrast to the unbridled exuberance of Time Magazine, this series of legal works displays an anxious trepidation about the legal ramifications associated with the rise of social networking services. In his tour de force, The Future of Reputation: Gossip, Rumor, and Privacy on the Internet, Daniel Solove considers the implications of social networking services, such as Facebook and YouTube, for the legal protection of reputation under privacy law and defamation law. Andrew Kenyon’s edited collection, TV Futures: Digital Television Policy in Australia, explores the intersection between media law and copyright law in the regulation of digital television and Internet videos. In The Future of the Internet and How to Stop It, Jonathan Zittrain explores the impact of ‘generative’ technologies and ‘tethered applications’—considering everything from the Apple Mac and the iPhone to the One Laptop per Child programme.

When the price is not right: Technology price gouging in Australia

Apple Inc. has often portrayed itself as the champion of consumers, with its advertising campaigns on “1984”, “Think Different”, and “Rip, Mix, Burn”. However, this reputation has been called into question after Apple refused to appear before the Parliament’s inquiry into IT Pricing in Australia and explain its pricing policies in Australia.

Milling innovations at Rocky Point

This paper reviews the innovations that have been introduced in the milling train at Rocky Point mill since 2001 and provides some operational, performance and maintenance comparisons of the technologies in use. The decision to install BHEM mills in the #2 and #3 mill positions to complement the six-roll mills in the #1 and #4 mill positions has proven a good one. Satisfactory performance is being obtained by these mills while maintenance costs are significantly less. Very good #1 mill extraction and final bagasse moisture content are being achieved. The innovation of using Hägglunds hydraulic drives at higher speed…

Introduction to "Business innovation and disruption in the music industry"

Similar to most other creative industries, the evolution of the music industry is heavily shaped by media technologies. This was equally true in 1999, when the global recorded music industry had experienced two decades of continuous growth largely driven by the rapid transition from vinyl records to Compact Discs. The transition encouraged avid music listeners to purchase much of their music collections all over again in order to listen to their favourite music with ‘digital sound’. As a consequence of this successful product innovation, recorded music sales (unit measure) more than doubled between the early 1980s and the end of the 1990s. It was with this backdrop that the first peer-to-peer file sharing service was developed and released to the mainstream music market in 1999 by the college student Shawn Fanning. The service was named Napster and it marks the beginning of an era that is now a classic example of how an innovation is able to disrupt an entire industry and make large swathes of existing industry competences obsolete. File sharing services such as Napster, followed by a range of similar services in its path, reduced physical unit sales in the music industry to levels that had not been seen since the 1970s. The severe impact of the internet on physical sales shocked many music industry executives who spent much of the 2000s vigorously trying to reverse the decline and make the disruptive technologies go away. At the end, they learned that their efforts were to no avail and the impact on the music industry proved to be transformative, irreversible and, to many music industry professionals, also devastating. Thousands of people lost their livelihood, large and small music companies have folded or been forced into mergers or acquisitions. But as always during periods of disruption, the past 15 years have also been very innovative, spurring a plethora of new music business models. These new business models have mainly emerged outside the music industry and the innovators have been often been required to be both persuasive and persistent in order to get acceptance from the risk-averse and cash-poor music industry establishment. Apple was one such change agent that in 2003 was the first company to open up a functioning and legal market for online music. iTunes Music Store was the first online retail outlet that was able to offer the music catalogues from all the major music companies; it used an entirely novel pricing model, and it allowed consumers to de-bundle the music album and only buy the songs that they actually liked. Songs had previously been bundled by physical necessity as discs or cassettes, but with iTunes Music Store, the institutionalized album bundle slowly started to fall apart. The consequences had an immediate impact on music retailing and within just a few years, many brick and mortar record stores were forced out of business in markets across the world. The transformation also had disruptive consequences beyond music retailing and redefined music companies’ organizational structures, work processes and routines, as well as professional roles. iTunes Music Store in one sense was a disruptive innovation, but it was at the same time relatively incremental, since the major labels’ positions and power structures remained largely unscathed. The rights holders still controlled their intellectual properties and the structures that guided the royalties paid per song that was sold were predictable, transparent and in line with established music industry practices.

The effects of gas and air flow distributions on the performance of the Farleigh No. 3 boiler

As more raw sugar factories become involved in the manufacture of by-products and cogeneration, bagasse is becoming an increasingly valuable commodity. However, in most factories, most of the bagasse produced is used to generate steam in relatively old and inefficient boilers. Efficient bagasse fired boilers are a high capital cost item and the cost of supplying the steam required to run a sugar factory by other means is prohibitive. For many factories a more realistic way to reduce bagasse consumption is to increase the efficiency of existing boilers. The Farleigh No. 3 boiler is a relatively old low efficiency boiler. Like many in the industry, the performance of this boiler has been adversely affected by uneven gas and air flow distributions and air heater leaks. The combustion performance and efficiency of this boiler have been significantly improved by making the gas and air flow distributions through the boiler more uniform and repairing the air heater. The estimated bagasse savings easily justify the cost of the boiler improvements.

Xylan-Degrading Enzymes from the Thermophilic Fungus Humicola Zanuginosa (Griffon and Maublanc) Bunce: Action Pattern of Xylanase and beta-Glucosidase on Xylans, Xylooligomers and Arabinoxylooligomers

The mode of action of xylanase and beta-glucosidase purified from the culture filtrate of Humicola lanuginosa (Griffon and Maublanc) Bunce on the xylan extracted from sugarcane bagasse and on two commercially available larchwood and oat spelt xylans, on xylooligomers and on arabinoxylooligomers was studied. While larchwood and oat spelt xylans were hydrolyzed to the same extent in 24 h, sugarcane bagasse xylan was hydrolyzed to a lesser extent in the same period. It was found that the rate of hydrolysis of xylooligomers by xylanase increased with increase in chain length, while beta-glucosidase acted rather slowly on all the oligomers tested. Xylanase exhibited predominant ''endo'' action on xylooligomers attacking the xylan chain at random while beta-glucosidase had ''exo'' action, releasing one xylose residue at a time. On arabinoxylooligomers, however, xylanase exhibited ''exo'' action. Thus, it appears that the presence of the arabinose substituent has, in some way, rendered the terminal xylose-xylose linkage more susceptible to xylanase action. It was also observed that even after extensive hydrolysis with both the enzymes, substantial amounts of the parent arabinoxylooligomer remained unhydrolyzed together with the accumulation of arabinoxylobiose. It can therefore be concluded that the presence of the arabinose substituent in the xylan chain results in linkages that offer resistance to both xylanase and beta-glucosidase action.

Josh lovegrove: Infinite

Research background: Infinite by Josh Lovegrove is an extended play album co-produced in collaboration with ARIA-nominated artist Mark Sholtez. The album consists of original songs written by Lovegrove, and songs co-written by Lovegrove, Carfoot and Sholtez. The scholarly context of the project is informed by studies of songwriting and ambiguity by Negus and Astor, new approaches to the study of record production associated with Zagorski-Thomas, and studies of creative labour by Hesmondhalgh and Baker. The project focused on the dynamics of musical performance and production in the recording studio, investigating the interface between the creative tasks of songwriting, production and performance in the recording of popular music. The project asked, in what ways do collaborative songwriting and production processes overlap, how has the nature of creative labour changed as a result of new forms of digital recording technology, and how can these aspects inform developments in the learning and teaching of popular music? Research contribution: The project has demonstrated the nuanced ways that the practices of record production have changed in the face of technological developments, and how this has impacted upon the specific forms and divisions of creative labour. Research significance: The project resulted in a well-reviewed album release that has further established Lovegrove’s reputation as a performer and songwriter. The creative work underpins ongoing research into the nature of popular music production, in particular how the nature of collaborative songwriting can inform innovation in the learning and teaching of popular music.

Mrs Curly and the Norwegian Smoking Pipe

Research background: Mrs Curly and the Norwegian Smoking Pipe is a full-length album and book release, produced in collaboration with renowned multi-instrumentalist Linsey Pollak. The project involved the recording and production of Pollak’s original compositions and arrangements of traditional works, drawing on hybrid digital-analog production techniques. The recording of the album was informed by prior scholarly work by Taylor, Feld, Wong and others. These existing studies have discussed the complexities of intercultural collaboration, and the types of cultural politics that are involved in the recording and distribution of what has been known by the term ‘World Music.’ Aspects of applied ethnomusicology have informed the creative work, as a means of interpreting the implicit and explicit complexities that arise through the recording and dissemination of intercultural creative practice. The project asked the research question, in what ways is intercultural music making effected by collaborative practices in the recording studio? Research contribution: This project has identified that the recording and production of intercultural music making involves a complex amalgam of aspects of live or ‘authentic’ performance practices, alongside highly mediated production practices that are influenced by new forms of digital recording technology. Research significance: The compact disc and book was released and promoted on the Marata Music label. The song ‘Plačam za’ was nominated in the World category of the 2015 Queensland Music Awards. The research context of the work is detailed in Gavin Carfoot, 2015 (in press), ‘Musical discovery, colonialism and the possibilities of intercultural communication through music’ in Popular Communication.

Access path query language for relational database systems

Database management systems offer a very reliable and attractive data organization for fast and economical information storage and processing for diverse applications. It is much more important that the information should be easily accessible to users with varied backgrounds, professional as well as casual, through a suitable data sublanguage. The language adopted here (APPLE) is one such language for relational database systems and is completely nonprocedural and well suited to users with minimum or no programming background. This is supported by an access path model which permits the user to formulate completely nonprocedural queries expressed solely in terms of attribute names. The data description language (DDL) and data manipulation language (DML) features of APPLE are also discussed. The underlying relational database has been implemented with the help of the DATATRIEVE-11 utility for record and domain definition which is available on the PDP-11/35. The package is coded in Pascal and MACRO-11. Further, most of the limitations of the DATATRIEVE-11 utility have been eliminated in the interface package.

An improved coattractant for pheromone trapping of Carpophilus spp. (Coleoptera: Nitidulidae)

Fermenting apple juice (FAJ) contained within polyacrylamide granules was an effective pheromone coattractant for Carpophilus davidsoni in trapping experiments conducted in stone fruit orchards in southern New South Wales. Fermenting apple juice-baited traps captured as many beetles as traps baited with the 'standard' coattractant fermenting bread dough (FBD), either alone or in combination with aggregation pheromone. Increasing the interval of FAJ replacement to 2 weeks instead of 1 week, as is necessary for FBD, did not reduce trapping efficiency. Replacement of FAJ every three weeks did not affect captures of C. davidsoni in one experiment but did reduce captures of Carpophilus mutilatus. In a second experiment, captures of C. davidsoni were also reduced. Fermenting apple juice contained within polyacrylamide granules replaced at fortnightly intervals is an effective, convenient and practical pheromone coattractant for Carpophilus spp.