The use of short chain volatile fatty acids in fine coal preparation
- Authors: Denby, B. , Elverson, C. , Hall, Stephen
- Date: 2002
- Type: Text , Journal article
- Relation: Fuel Vol. 81, no. 5 (2002), p. 595-603
- Full Text: false
- Reviewed:
- Description: Froth flotation and selective agglomeration are two techniques, which can be employed for the recovery of fine coals. Short chain volatile fatty acids (VFAs) contained in landfill-derived liquids are similar in structure to many of the organic chemicals employed in both processes. The results from laboratory investigations, based on flotation and selective agglomeration techniques, have demonstrated that VFAs can substitute for some, or all, of the commercial reagents currently used. The results of these investigations, using VFAs and landfill gas condensates, are presented, along with discussion of their potential application to fine coal recovery. © 2001 Elsevier Science Ltd. All rights reserved.
- Description: 2003000131
Galvanic and acoustic vestibular stimulation activate different populations of vestibular afferents
- Authors: Bacsi, Ann M , Watson, Shaun , Colebatch, James G
- Date: 2003
- Type: Text , Journal article
- Relation: Clinical Neurophysiology Vol. 114, no. 2 (2003), p. 359-365
- Full Text: false
- Reviewed:
- Description: OBJECTIVE: To deduce whether similar or distinct populations of vestibular afferents are activated by acoustic and galvanic vestibular stimulation by comparing the effectiveness of 'matched' stimuli in eliciting vestibulospinal reflexes. METHODS: Twelve subjects (5 men, 7 women) underwent individual 'matching' of 2 ms tone burst and galvanic stimuli, using vestibulocollic reflexes so that corrected reflex amplitudes to tone burst and galvanic stimuli were within 10% of each other. These same intensities were then administered using 20 ms durations to determine whether they were equally effective in evoking vestibulospinal responses. RESULTS: Corrected reflex amplitudes for vestibulocollic responses to tone burst and galvanic stimulation were not significantly different for the right (P=0.45) or left (P=0.68) sides. All subjects had vestibulospinal responses to galvanic stimulation (average intensity 4.0 mA for both sides). The short latency (SL) and medium latency (ML) components of the vestibulospinal reflexes were larger after galvanic compared to tone burst stimulation in 11 of 12 subjects (P<0.01). CONCLUSIONS: Despite evoking equal-sized vestibulocollic reflexes, there was a clear dissociation between the magnitude of tone burst and galvanic-induced vestibulospinal reflexes. Galvanic stimulation evoked SL and ML reflexes in all subjects. Tone burst stimuli evoked only small SL reflexes and, in most cases, no ML reflexes. Acoustically-evoked vestibulocollic reflexes are likely to be due to saccular excitation. The limited effectiveness of longer tone burst stimuli to evoke ML vestibulospinal reflexes suggests that saccular afferents have, at most, only a minor role in the production of these reflexes. We conclude that galvanic stimulation is more effective in eliciting vestibulospinal reflexes than tone burst stimulation, and that the two methods activate different populations of vestibular afferents.
Activation of proteases in an anaerobic sulphidogenic bioreactor
- Authors: Whiteley, Chris , Pletschke, Brett , Rose, Peter , Tshivhunge, Sylvia , Watson, Shaun , Whittington-Jones, Kevin
- Date: 2004
- Type: Text , Journal article
- Relation: Biotechnology Letters Vol. 26, no. 1 (2004), p. 55-59
- Full Text: false
- Reviewed:
- Description: Activities of proteases were stimulated by specific sulphur metabolites during the enhanced hydrolysis of complex polymeric organic carbon in an anaerobic sulphidogenic environment. While sulphate at 1000 mg l(-1) inhibited proteases by 50%, there was a 2.5-fold increase in activity of proteases by added sulphite and a 3.6-fold increase from added sulphide. Two hypothetical models are proposed. First the sulphur species, sulphite (HSO3-) and sulphide (HS-), liberated at different times during the sulphate reduction process, directly activate the proteases, which are associated with the organic particulate matter, leading to a subsequent enhancement of hydrolysis of polymeric material. Second, they indirectly activate the proteases by neutralising the cations on the floc surface disrupting the integrity of the organic particulate floc therebye releasing further entrapped enzymes from the organic particulate matter.
FT-Raman studies of a range of polyimides subjected to high-energy Radiations at room and elevated temperatures
- Authors: Devasahayam, Sheila , Hill, David , Connell, John
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Applied Polymer Science Vol. 101, no. 3 (2006), p. 1575-1582
- Full Text: false
- Reviewed:
- Description: A range of polyimides have been subjected to electron beam radiolysis at different temperatures. These polyimides were chemically designed to suit space applications, being either transparent or having groups which provide oxidation resistance. The structural changes that occur in the polyimides, when subjected to electron beam irradiation doses up to 18.5 MGy and up to temperatures close to their glass transition temperatures, were studied using FT-Raman spectroscopy. The range of polyimides studied included a series of perfluoropolyimides, a silicon-modified polyimide, and Ultem. The changes in the Raman peak intensities of the different groups indicated scission reactions involving the imide rings and ether linkages. (c) 2006 Wiley Periodicals, Inc.
Concepts of accident causation and their role in safe design among engineering students
- Authors: Hall, Stephen , Culvenor, John , Cowley, Stephen , Else, Dennis
- Date: 2007
- Type: Text , Conference paper
- Relation: Paper presented at 18th conference of the Australasian Association for Engineering Education, Melbourne, Victoria : 9th-13th December 2007
- Full Text:
- Description: Safe design is a strong theme at present in Australia. To ‘eliminate hazards at the design stage’ is one of the five national priorities set out by the National OHS Strategy. The Australian Safety and Compensation Council have recently released both a guideline for safe design and an engineering education package. Safe design is not only about engineering decisions. Engineers are however an important group. This paper reports on a survey to evaluate perceptions of student engineers on topics relevant to the advancement of safe design including perceptions of: control versus fatalism; accident causation; and perceptions of the role played by engineers.
- Description: 2003004787
Gold particle clustering : A new consideration in sampling applications
- Authors: Dominy, Simon , Platten, Ian
- Date: 2007
- Type: Text , Journal article
- Relation: Transactions of the Institutions of Mining and Metallurgy, Section B: Applied Earth Science Vol. 116, no. 3 (2007), p. 130-142
- Full Text: false
- Reviewed:
- Description: Recent research indicates that an enhanced coarse gold problem may be present in some gold deposits. This can be due to the presence of gold particle clusters that give the effect of individual coarse-gold particles and leads to a high constitution heterogeneity (CH). These clusters, which may be distributed on the centimetre-scale or greater, give rise to high assay variability in field samples. However, once a sub-sample is pulverised, the effect of the clusters may be removed if the individual gold particles making up the clusters are liberated. Thus any resulting pulp will tend to have a low variability, unless true coarse-gold particles exist. Clusters are readily recognised in coarse gold deposits where they accentuate existing high nugget effect and CH. Clusters may however also occur in fine gold deposits where they produce an apparent coarse gold style. This is signaled by an unexpectedly high nugget effect from variography and poor correlation between field sample duplicates. The Gy sampling equation is applied to model coarse and fine gold deposits with clustered and non-clustered gold grains. Case studies illustrating observed effects of clustering are presented. If clustered particles exist, then proper protocol design at the field and early laboratory stage is paramount. The sample characterisation stage should include an assessment of possible gold article clustering, in addition to the standard descriptions of the gold particle size distribution. © 2007 Institute of Materials, Minerals and Mining and The AusIMM.
- Description: C1
- Description: 2003005555
Application of high-speed countercurrent chromatography for the isolation of sulforaphane from broccoli seed meal
- Authors: Liang, Hao , Li, Chunfang , Yuan, Qipeng , Vriesekoop, Frank
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Agricultural and Food Chemistry Vol. 56, no. 17 (2008), p. 7746-7749
- Full Text: false
- Description: In order to produce large amounts of pure sulforaphane for research purposes, a novel method using high-speed countercurrent chromatography (HSCCC) was developed. Without any initial cleanup steps, sultoraphane was successfully purified from the ethyl acetate extract of the broccoli seed meal by HSCCC. The separation was performed with two-phase solvent systems: n-hexane/ethyl acetate/ methanol/water (1:5:1:5, v/v/v/v). From 850 mg of the ethyl acetate extract, 186 mg of sultoraphane was isolated with the solvent system. The purified compound was over 97% purity as determined by HPLC analysis, and the chemical structure was confirmed by MS and 1H and 13C NMR. © 2008 American Chemical Society.
Constrained action selection in children with developmental coordination disorder
- Authors: Pettit, Lewis , Charles, Jennifer , Wilson, Andrew , Plumb, Mandy , Brockman, Anne , Williams, Justin , Mon-Williams, Mark
- Date: 2008
- Type: Text , Journal article
- Relation: Human Movement Science Vol. 27, no. 2 (2008), p. 286-295
- Full Text: false
- Reviewed:
- Description: The effect of advance ('precue') information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n=10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic.
Online corrections in children with and without DCD
- Authors: Plumb, Mandy , Wilson, Andrew , Mulroue, Amy , Brockman, Anne , Williams, Justin , Mon-Williams, Mark
- Date: 2008
- Type: Text , Journal article
- Relation: Human Movement Science Vol. 27, no. 5 (2008), p. 695-704
- Full Text: false
- Reviewed:
- Description: Human arm movements need 'online' corrections due to noise in perception and action. A Step-Perturbation paradigm explored online corrections in control children and children with DCD aged between 7 and 13 years. Control children found the task straightforward: a distracter had no effect and they managed to stop relatively quickly. Children with DCD found the task difficult and the apparatus was modified accordingly (decreased postural and force production demands). The distracter affected some children with DCD and some found it difficult to stop. All of the DCD population showed poorer performance in both the perturbation and non-perturbation condition. Nevertheless, there was no interaction between group and condition. Thus, this study found no evidence for specific deficits in online correction mechanisms in DCD. We suggest that: (i) fundamental problems in generating basic movements can account for the documented difficulties in correcting on-going movements, and (ii) such fundamental difficulties make it very difficult to pinpoint specific mechanism deficits.
Performance analysis of a multistage interconnection network system based on a minimum cut set method
- Authors: Gunawan, Indra
- Date: 2008
- Type: Text , Journal article
- Relation: International Journal of Performability Engineering Vol. 4, no. 2 (2008 2008), p. 111-120
- Full Text: false
- Reviewed:
- Description: An interconnection network system consists of layers of switching elements connected together in a predefined topology providing the connectivity between the set of processors and the set of memory modules. Performance analysis of a network system is important as it determines the usability and the efficiency of the network to provide services. A shuffle-exchange network (SEN), a specific type of Multistage Interconnection Network (MIN) that consists of 2x2 switching elements, has been widely considered as a practical interconnection system. This paper presents a network reliability model based on a minimum cut set method for SEN systems. A general equation for large-scale network reliability is derived subsequently to reduce the complexity of the reliability analysis for the interconnection network system. Read more: http://www.ijpe-online.com/p2-performance-analysis-of-a-multistage-interconnection-network-system-based-on-a-minimum-cut-set-method.html#ixzz34m0gTAiy
Predictive mapping of powerful owl (Ninox strenua) breeding sites using Geographical Information Systems (GIS) in urban Melbourne, Australia
- Authors: Isaac, Bronwyn , Cooke, Raylene , Simmons, Dianne , Hogan, Fiona
- Date: 2008
- Type: Text , Journal article
- Relation: Landscape and Urban Planning Vol. 84, no. (2008), p. 212-218
- Full Text: false
- Reviewed:
- Description: Urban expansion is a principal process threatening biodiversity globally. It is predicted that over half of the world's population will reside in urban centres by 2010. If we are to conserve biodiversity, a shift in perspective from traditional ecological studies based in natural environments, to studies based in less natural environments is paramount. To effectively conserve species which occur in urban environments, comprehensive analysis is necessary to determine the processes that are driving this urban usage. Geographical Information Systems (GIS) technology provides a valuable tool for efficient spatial analysis and predictive mapping of species distributions. This study used GIS to analyze current breeding sites for the powerful owl, a vulnerable top order predator in urban Melbourne, Australia. GIS analysis suggests that a number of ecological attributes were influencing powerful owl usage of urban environments. Using these ecological attributes, predictive mapping was undertaken, which identified a number of potential breeding sites for powerful owls within urbanized Melbourne. Urban environments are traditionally perceived as “the wastelands” of natural environments, however, this study demonstrates that they have the potential to support apex predators, an important finding for the management of rare and threatened species.
A new methodology of mobile robot navigation : The agoraphilic algorithm
- Authors: McFetridge, Lachlan , Ibrahim, Yousef
- Date: 2009
- Type: Text , Journal article
- Relation: Robotics and Computer-Integrated Manufacturing Vol. 25, no. 3 (2009 2009), p. 545-551
- Full Text: false
- Reviewed:
- Description: The Agoraphilic algorithm is an optimistic approach to reactive path planning for mobile robot platforms. The technique uses virtual, attractive forces derived from the surrounding free space. Fuzzy logic is utilised to limit the ‘free-space’ force so as to promote the movement towards the goal. The algorithm was designed to be a robust technique for reactive navigation that could be implemented without the fuss of tuning the sensitive parameters required for other classical navigation routines. Several simulations plus some preliminary experimental results are presented here to demonstrate the algorithm's potential.
An adaptive borrow-and-return model for broadcasting videos
- Authors: Azad, Salahuddin , Murshed, Manzur
- Date: 2009
- Type: Text , Journal article
- Relation: IEEE Transactions on Multimedia Vol. 11, no. 4 (2009), p. 707-715
- Full Text: false
- Reviewed:
- Description: Yang proposed the concept of borrow-and-return (BR) to leverage the unused server bandwidth when a group of popular videos being broadcast with the FSFC (first segment on the first channel) broadcasting schemes in order to improve the mean waiting time (MWT) of the viewers with the help of additional receiving bandwidth available at the high-end clients. The BR model borrows the bandwidth of the videos with no new-coming viewers during a timeslot to speed up the transmission of the first segments of some of the remaining videos. In this paper, we first address the relative advantage issue among various possible BR schemes by developing a parametric generic BR (GBR) scheme controlled externally by independent borrow parameters. Later, we propose a new BR (NBR) model by incorporating an efficient transmission strategy to reduce the MWT further. Finally, an optimal NBR scheme is developed by augmenting with the optimal borrow parameters, which significantly outperforms the existing and new BR schemes in terms of overall MWT.
Combining segmental semi-Markov models with neural networks for protein secondary structure prediction
- Authors: Bidargaddi, Niranjan , Chetty, Madhu , Kamruzzaman, Joarder
- Date: 2009
- Type: Text , Journal article
- Relation: Neurocomputing Vol. 72, no. 3943-3950 (2009), p.3943-3950
- Full Text: false
- Reviewed:
- Description: Predicting the secondary structure of proteins from a primary sequence alone has been variously approached from either a classification or a generative model perspective. The most prominent classification methods have used neural networks, which involves mappings from a local window of residues in the sequence to the structural state of the central residue in the window, thus capturing the local interactions effectively. However, they fail to capture distant interactions among residues. The generative models based on Bayesian segmentation capture sequence structure relationships using generalized hidden Markov models with explicit state duration. They capture non-local interactions through a joint sequence-structure probability distribution based on structural segments. In this paper, we investigate a combined architecture of Bayesian segmentation at the first stage and neural network at the second stage which captures both local and non-local correlation, to increase the single sequence prediction accuracy. The combined architecture is further enhanced by using neural network optimization and ensemble techniques.
Fe and S K-edge XAS determination of iron-sulfur species present in a range of acid sulfate soils : Effects of particle size and concentration on quantitative XANES determinations
- Authors: Morgan, Kate , Burton, Edward , Cook, Perran , Raven, Mark , Fitzpatrick, Rob W. , Bush, Richard , Sullivan, Leigh , Hocking, Rosalie
- Date: 2009
- Type: Text , Conference paper
- Relation: 14th International Conference on X-ray Absorption Fine Structure (XAFS14); Camerino, Italy; 26th-31st July 2009. Vol. 190, p. 1-5
- Full Text: false
- Reviewed:
- Description: Acid sulfate soils (ASS) are soils and soft sediments in which sulfuric acid may be produced from iron sulfides or have been produced leaving iron oxyhydroxysulfates in amounts that have a long lasting effect on soil characteristics. If soil material is exposed to rotting vegetation or other reducing material, the Fe-oxyhydroxysulfates can be bacterially reduced to sulfides including disulfides (pyrite and marcasite), and Monosulfidic Black Ooze (MBO) a poorly characterised material known to be a mixture of iron sulfides (especially mackinawite) and organic matter. The chemistry of these environments is strongly affected by Fe and S cycling processes and herein we have sought to identify key differences in environments that occur as a function of Fe and S concentration. In addition to our chemical results, we have found that the effects of particle size on self absorption in natural sediments play an important role in the spectroscopic identification of the relative proportions of different species present. © 2009 IOP Publishing Ltd.
Introducing differential kinematics to mechanical engineering students
- Authors: Sultan, Ibrahim
- Date: 2009
- Type: Text , Journal article
- Relation: International Journal of Mechanical Engineering Education Vol. 37, no. 3 (2009), p. 210-222
- Full Text:
- Description: Differential kinematics offers a simplified alternative to closed-form input-output equations needed to study the geometrical behaviour of linkages. For most linkages, these closed-form equations are either too messy or not possible to obtain, a fact that sometimes reflects negatively on how mechanical engineering students perceive the subject of mechanism analysis. On the other hand, differential models can easily be utilised in numerical methods designed to encourage these students to tackle even more difficult problems than currently being considered in academic programmes. In this paper, an approach is presented to facilitate this process. The mathematical procedure is based on the use of matrices referred to as kinematic Jacobians. The determinants of these matrices offer invaluable insights into the linkage mobility. These matrices are explained and used in a practice numerical example.
- Description: 2003008219
The Australian Bush Fly (Musca vetustissima) as a potential vector in the transmission of foodborne pathogens at outdoor eateries
- Authors: Vriesekoop, Frank , Shaw, Rachel
- Date: 2009
- Type: Text , Journal article
- Relation: Foodborne Pathogens and Disease Vol. 7, no. 3 (2009), p. 275-279
- Full Text: false
- Reviewed:
- Description: Abstract Australian outdoor activities are often accompanied by a barbeque (BBQ) with family, friends, and guests, which are often interrupted by uninvited guests in the form of the Australian bush fly, Musca vetustissima. We investigated the bacterial loading associated with the Australian bush in three different environments: on a cattle farm, in a typical urban area (shopping center car park), and at a BBQ. The highest bacterial populations per fly were found to occur in a farm environment (9.1×104 CFU per fly), whereas the bacterial population was lowest on flies caught in an urban environment (1.9×104 CFU per fly). The median CFU per fly caught near a BBQ was 5.0×104. Escherichia coli was the most commonly isolated potential pathogen, whereas Shigella sp. was the least common bacterial isolate that was screened. All isolated foodborne pathogens or indicator bacteria were screened for antibiotic resistance against commonly prescribed antibiotics. This revealed a very high prevalence of multidrug resistance, especially among the Salmonella and Shigella isolates of 94% and 87% resistance, respectively, against amoxicillin, roxythromycin and cefaclor.
An environment-aware mobility model for wireless ad hoc network
- Authors: Ahmed, Sabbir , Karmakar, Gour , Kamruzzaman, Joarder
- Date: 2010
- Type: Text , Journal article
- Relation: Computer Networks Vol. 54, no. 9 (2010), p. 1470-1489
- Full Text: false
- Reviewed:
- Description: Simulation is a cost effective, fast and flexible alternative to test-beds or practical deployment for evaluating the characteristics and potential of mobile ad hoc networks. Since environmental context and mobility have a great impact on the accuracy and efficacy of performance measurement, it is of paramount importance how closely the mobility of a node resembles its movement pattern in a real-world scenario. The existing mobility models mostly assume either free space for deployment and random node movement or the movement pattern does not emulate real-world situation properly in the presence of obstacles because of their generation of restricted paths. This demands for the development of a node movement pattern with accurately representing any obstacle and existing path in a complex and realistic deployment scenario. In this paper, we propose a general mobility model capable of creating a more realistic node movement pattern by exploiting the concept of flexible positioning of anchors. Since the model places anchors depending upon the context of the environment through which nodes are guided to move towards the destination, it is capable of representing any terrain realistically. Furthermore, obstacles of arbitrary shapes with or without doorways and any existing pathways in full or part of the terrain can be incorporated which makes the simulation environment more realistic. A detailed computational complexity has been analyzed and the characteristics of the proposed mobility model in the presence of obstacles in a university campus map with and without signal attenuation are presented which illustrates its significant impact on performance evaluation of wireless ad hoc networks.
Distribution and migration of nitrobenzene in water following a simulated spill
- Authors: Li, Peijun , Yin, Wei , Li, Peng , Li, Xiaojun , Zhang, Chungui , Stagnitti, Frank , Xiong, Xianzhe
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Hazardous Materials Vol. 182, no. 1-3 (2010), p. 787-791
- Full Text: false
- Reviewed:
- Description: Releases of nitrobenzene into the aquatic environment pose a threat to human health and aquatic resources, and have attracted much attention world-wide. In order to find out the distribution and migration patterns of pooled nitrobenzene underwater in different conditions, laboratory column experiments were designed to simulate stagnant water, flowing water and rainfall disturbance events. The results showed that in stagnant water there was a slow diffusion of the nitrobenzene from the pool leading to higher concentrations of the chemical deeper in the water column. In flowing water, the removal of the substance was rapid and water concentrations were much lower and more uniform throughout the column. The disturbance event brought a substantial quantity of nitrobenzene into the water column which then dissipated according to the flow regime. Analysis of the data showed that distribution pattern of nitrobenzene in the stagnant water column followed a logarithmic equation CNB=aln(t)+b, and in disturbed flowing water, the distribution pattern of nitrobenzene followed a negative exponential regression equation CNB=Ne-Mt. These conclusions have practical significance in developing remediation technologies for water polluted by nitrobenzene. © 2010 Elsevier B.V.
New control concept for a gantry tractor comprising a 'chorus line' of synchronized modules
- Authors: Ibrahim, Yousef , Spark, Ian , Percy, Andrew
- Date: 2010
- Type: Text , Journal article
- Relation: IEEE Transactions on Industrial Electronics Vol. 57, no. 2 (2010), p. 762-768
- Full Text:
- Reviewed:
- Description: A new method of automatically maneuvering a gantry tractor through right-angle turns, U-turns, and narrow gates is described in this paper. In order to maximize traction and maneuverability, both the wheel-angle steering effect and the drive-wheel-speed steering effect are integrated. This technique produces identical and cooperative redundant steering systems. The necessary wheel angles and drive wheel speed have been simulated. The advantage of cooperative redundancy is that when any steering system begins to fail, it is reinforced by the other steering system