List of Records in Journal Articles - RMIT Research Repository

A polyaniline nanofibre electrode and its application in a self-powered photoelectrochromic cell

2009-09-01T00:00:00Z

Polyaniline (PANI) nanofibre films were fabricated on an indium-tin oxide (ITO) glass substrate through a controlled electropolymerization process. The PANI nanofibres grow vertically on an ITO substrate and are tapered, with average diameters of 20 and 15 nm for the base and top, respectively. The influence of the electrochemical conditions on the nanostructural formation of the PANI films was investigated and the optimized parameters of the electrodeposition were obtained. The optical and electrical properties of the PANI nanofibre electrodes were studied. Employing these PANI nanofibre films as the electrochromic electrode, we fabricated an electrochromic display (ECD) and a self-powered photoelectrochromic cell. The electrochromic and photoelectric properties of the ECD and photoelectrochromic cell are discussed in this paper. The PANI nanofibre based ECD and photoelectrochromic cells have a rapid response compared to conventional thin films due to the high aspect ratio of the nanostructured PANI film.

A polyaniline/WO3 nanofiber composite-based ZnO/64� YX LiNbO(3)SAW hydrogen gas sensor

2009-07-17T00:00:00Z

Polyaniline/WO3 nanofiber composite-based surface acoustic wave (SAW) gas sensor has been investigated towards hydrogen (H2). Chemical oxidative polymerization of aniline was employed to synthesize polyaniline nanofibers with WO3 nanoparticles. The nanocomposite was deposited onto a layered ZnO/64� YX LiNbO3 SAW transducer. The sensor was exposed to various concentrations of H2 gas and operated at room temperature. The sensor response was found to be 7 kHz towards 1% of H2 in synthetic air. A fast response and recovery with good repeatability in a stable baseline condition were observed at room temperature.

A polynomial approach to cocycles over elementary abelian groups

Farmer, D og Horadam, K — 2009-07-17T14:00:46Z

We derive bivariate polynomial formulae for cocycles and coboundaries in Z2(xs2124pn,xs2124pn), and a basis for the (pn-1-n)-dimensional GF(pn)-space of coboundaries. When p=2 we determine a basis for the $(2^n + {n\choose 2} -1)$-dimensional GF(2n)-space of cocycles and show that each cocycle has a unique decomposition as a direct sum of a coboundary and a multiplicative cocycle of restricted form.

A polyphasic approach for assessing the suitability of bioremediation for the treatment of hydrocarbon-impacted soil

2013-03-12T08:58:00Z

Bioremediation strategies, though widely used for treating hydrocarbon-contaminated soil, suffer from lack of biodegradation endpoint accountability. To address this limitation, molecular approaches of alkB gene analysis and pyrosequencing were combined with chemical approaches of bioaccessibility and nutrient assays to assess contaminant degrading capacity and develop a strategy for endpoint biodegradation predictions. In long-term hydrocarbon-contaminated soil containing 10.3 g C10-C36 hydrocarbons kg− 1, 454 pyrosequencing detected the overrepresentation of potential hydrocarbon degrading genera such as Pseudomonas, Burkholderia, Mycobacterium and Gordonia whilst amplicons for PCR-DGGE were detected only with alkB primers targeting Pseudomonas. This indicated the presence of potential microbial hydrocarbon degradation capacity in the soil. Using non-exhaustive extraction methods of 1-propanol and HP-β-CD for hydrocarbon bioaccessibility assessment combined with biodegradation endpoint predictions with linear regression models, we estimated 33.7% and 46.7% hydrocarbon removal respectively. These predictions were validated in pilot scale studies using an enhanced natural attenuation strategy which resulted in a 46.4% reduction in soil hydrocarbon content after 320 days. When predicted biodegradation endpoints were compared to measured values, there was no significant difference (P = 0.80) when hydrocarbon bioaccessibility was assessed with HP-β-CD. These results indicate that a combination of molecular and chemical techniques that inform microbial diversity, functionality and chemical bioaccessibility can be valuable tools for assessing the suitability of bioremediation strategies for hydrocarbon-contaminated soil

Apoptosis in skeletal muscle myotubes is induced by ceramides and is positively related to insulin resistance

2009-02-18T09:53:18Z

Fatty acid-induced apoptosis occurs in pancreatic -cells and contributes to the metabolic syndrome. Skeletal muscle insulin resistance is mediated by fatty acid oversupply, which also contributes to the metabolic syndrome. Therefore, we examined whether fatty acids induce apoptosis in skeletal muscle myotubes, the proapoptotic signaling involved, and the effects on insulin sensitivity. Exposure of L6 myotubes to palmitate induced apoptosis, as demonstrated by increased caspase-3 activation, phosphatidylserine exposure on the plasma membrane, and terminal deoxynucleotide transferase dUTP nick end labeling and DNA laddering, both markers of DNA fragmentation. Ceramide content was concomitantly increased, indicating a potential role for ceramides in palmitate-induced apoptosis. Supporting this notion, reducing stearoyl-CoA desaturase-1 (SCD-1) protein content with short interfering RNA resulted in ceramide accumulation and was associated with increased apoptosis in the absence of palmitate. Furthermore, the membrane-permeable C2-ceramide enhanced apoptosis in myotubes, whereas the ceramide synthase inhibitor, fumonisin B1, abrogated the proapoptotic effects of palmitate. Insulin-stimulated glucose uptake was inhibited by palmitate treatment, whereas the addition of effector caspase inhibitors [Ac-DEVD-aldehyde (DEVD-CHO), Z-DQMD-FMK] independently restored >80% of the insulin-stimulated glucose uptake. These effects were observed independently from changes in the protein content of insulin signaling proteins, suggesting that proteosomal degradation is not involved in this process. We conclude that lipoapoptosis occurs in skeletal muscle myotubes, at least partially via de novo ceramide accumulation, and that inhibiting downstream apoptotic signaling improves glucose uptake in vitro.

Apoptotic and necrotic stages of Symbiodinium (Dinophyceae) cell death activity: Bleaching of soft and scleractinian corals

Strychar, K og Sammarco, P og Piva, T — 2013-02-19T13:10:00Z

Mechanisms which regulate abundances of Symbiodinium populations during bleaching are not yet fully understood. Currently proposed mechanisms include cell exocytosis, host-cell detachment, apoptosis and necrosis. Here we have analysed zooxanthellae of soft and scleractinian corals under thermal stress using light, fluorescence and transmission electron microscopy (TEM) and confirmed that different stages of apoptotic and necrotic cell death of Symbiodinium occur. The diagnostic characteristic of apoptosis within Symbiodinium cells included nuclear and organelle condensation, membrane blebbing, the formation of apoptotic bodies and mitochondrial swelling. Necrotic cells swell, cytoplasmic organelles fuse and burst, followed by Symbiodinium cell membrane disintegration and release of cytosolic contents. In addition, TEM showed that apoptotic and necrotic processes are initiated in situ. Symbiont cells in the process of dying in situ therefore reduce the likelihood of recolonization upon expulsion from the host.

A population survey on the use of 24 common medicinal herbs in Australia

2009-07-17T00:00:00Z

Background: Herbal medicine use is common in Australia but little is known about the use of individual herbs. Methods: A cross-sectional population survey conducted in 2007 with a sample of 2526, in the Australian state of Victoria. Results: Almost a quarter (22.6%, 95% confidence interval (CI): 20.9-24.2%) of survey participants had used at least one medicinal herb in the preceding 12 months. Aloe vera, garlic and green tea were the most popular, each used by about 10% of participants. Health enhancement was the most common reason for herbal medicine use (69.6% of users) but relatively high proportions of users sought relief of specific medical conditions. Over 90% considered their herbal medicine to be very or somewhat helpful. Less than half (46.6%) the users were aware that there were potential risks associated with herbal medicine. Relatively high proportions of female users had taken herbal medicine whilst pregnant (14.4%) and/or whilst breast feeding (10.0%). Over half (50.9%) of herbal medicine users had also used Western medicine for the same medical condition in the 12-month period. Almost the same proportion (49.9%) had used both forms of medication on the same day. In deciding whether or not to use herbal medicine, the vast majority of survey participants indicated that they would accept the advice of their medical practitioner. Conclusions: In addition to health enhancement, specific herbs are commonly used to treat a range of medical conditions, without clear evidence of efficacy. Concurrent use of herbal and conventional medicine is relatively common and the majority of herbal medicine users are not aware of potential adverse effects. It appears that medical practitioners could exert significant influence on their patients' decisions about herbal medicine use.

Apparent volumetric shrinkage study of RTM6 resin during the curing process and its effect on the residual stresses in a composite

Magniez, K og Vijayan, A og Finn, N — 2013-05-06T13:39:00Z

A comprehensive characterization of the volumetric shrinkage of a commercially important aerospace resin (RTM6) during the various stages of the curing process was studied. The apparent volumetric shrinkage, evaluated from density measurements at room temperature, was correlated with the progress of epoxide conversion. During the entire curing process, the apparent volume shrinkage was found to be less than 3% and occurred before vitrification. A slight re-expansion of the resin, attributed to self-antiplasticization effects, was observed during postcuring at 1808C. It was concluded that residual stresses were not generated due to chemical cross-linking during curing but rather from thermal contraction occurring during the cooling stage after cure. A photo-elastic method was used to characterize residual stresses during cooling in a deliberately engineered resin rich hole of a carbon fiber/RTM6 composite. The residual stress was found to reach approximately 28 MPa, which is in good agreement with the value calculated from the shrinkage and elastic moduli. It is proposed that this simple method can be provide insights useful to the design and materials selection processes by measuring and localizing residual stresses from resin during curing and or thermal cycling.

Applicability of published data for fatigue-limited design

Leary, M og Burvill, C — 2010-11-17T16:09:00Z

The use of published fatigue data provides an expedient basis for fatigue-limited engineering design by alleviating the necessity of explicit testing. However, published fatigue data often exhibits incomplete documentation of the associated test conditions. Incomplete documentation introduces uncertainties in fatigue life prediction that may limit the applicability of the published fatigue data for design applications. Characterization of the applicability of published fatigue data is critical for robust fatigue-limited design. However, no quantitative methods have been identified which respond to this requirement. A novel method has been developed to provide a systematic characterization of the applicability of published fatigue data based on internationally recognized standards. This method provides a conceptual mechanism to: 'identify the applicability of published fatigue test data for specific design scenarios' thereby informing engineers of potential limitations of published data and allowing prioritization of multiple data sources; 'identify material domains of insufficient applicability' thereby providing a robust basis for identifying beneficial fatigue test programs; 'compromise between design complexity and the uncertainties inherent in fatigue life prediction; 'define a framework for the appropriate documentation of published fatigue data. A sample of published fatigue data sources associated with a specific fatigue-limited safety' critical design scenario was assessed by the method presented in this paper. For the majority of the sampled references, the associated documentation was insufficient to allow the fatigue test data to be confidently applied to the subsequent design activity.

Applicability of the crack tip element analysis for damage prediction of composite T-joints

2010-09-20T11:31:09Z

The expanding application of polymeric composite materials in the Aerospace industry has led to the extension of its application to other industries such as the marine industry. A typical joint between the hull and bulkhead used in a monocoque structure is known as a T-joint. It consists of composite overlaminates over a shaped fillet to allow the transmission of direct and membrane shear stresses. The CTE (crack tip element) method offers the capability to provide accurate results with minimum computational resources. It is also an excellent damage prediction tool for composite laminates where oscillatory singularity exists at the crack tip. This paper describes the application of the CTE method for damage prediction of the T-joint. Issues involved in the current modeling approach and recommended solutions are discussed.

Application of acacia natural dyes on cotton by pad dyeing

Ratnapandian, S og Fergusson, M og Wang, L — 2012-03-16T07:59:00Z

Coloration of textiles, traditionally achieved using natural dyes, commonly employs synthetic dyes at the industrial level. A revival of commercial interest in natural dyes has opened several research avenues. This paper investigates the application by padding of cotton fabric with 10 g/l of two natural dyes derived from the Acacia plant family. Three mordanting techniques were studied; of which post-mordanting produced the most even shade. Among the two mordants investigated, the use of copper sulfate resulted in a level beige shade at 15 g/l concentration while ferrous sulfate performed best at 5 g/l yielding a yellow-grey shade. An optimum process-sequence for the copper sulfate mordant was "pad (dye)¨dry¨steam followed by pad (mordant)¨steam¨dry", and for ferrous sulfite it was "pad (dye)¨steam¨dry followed by pad (mordant)¨steam¨dry". Typically a change in mordant resulted in a different shade with the same dye. The study concluded that padding is a readily adaptable process for the dyeing of cotton using natural dyes and acceptable fastness in shades can be obtained.

Application of a pathogenicity marker found in Escherichia coli for the assessment of irrigation water quality

2009-12-09T00:00:00Z

A polymerase chain reaction (PCR)-based method was developed to differentiate between pathogenic and nonpathogenic Escherichia coli (E. coli). A pathogenicity marker, linked to the deletion of the ygfB gene, was identified in 80% of the clinical E. coli isolates tested. This marker, combined with the malic acid dehydrogenase gene, formed the duplex PCR that was subsequently used to screen E. coli isolates recovered from two secondary wastewater treatment plants (STPs) and a river site. All waters samples are used to irrigate dairy farm pasture in the West Gippsland region of Victoria, Australia. Results from three consecutive months of sampling (December 2001 and January and February 2002) indicated that Longwarry STP showed 8, 8, and 0% pathogenic E. coli; Pakenham STP showed 0, 12.5, and 33%; and the Bunyip river site showed 20, 12, and 25% respectively.

Application of artificial neural networks in linear profile monitoring

2010-11-17T16:09:00Z

In many quality control applications the quality of process or product is characterized and summarized 16 by a relation (profile) between a response variable and one or more explanatory variables. Such profiles 17 can be modeled using linear or nonlinear regression models. In this paper we use artificial neural net- 18 works to detect and classify the shifts in linear profiles. Three monitoring methods based on artificial 19 neural networks are developed to monitor linear profiles. Their efficacies are assessed using average 20 run length criterion.

Application of atomic force microscopy and grating coupler for the characterization of biosensor surfaces

2010-12-06T00:00:00Z

Atomic force microscopy (AFM) and an optical grating coupler system were used to improve the understanding of the biosensing layer on a Ta2O5-light-guiding surface. Exemplary, we investigated the immobilization of the protein avidin, the subsequent binding of biotinylated oligonucleotides and hybridization of a complementary 12-mer. The AFM measurements revealed the height of -1.6 nm for a single avidin molecule, while the thickness of the avidin layer on the biosensor surface seemed to be 2.8-3.0 nm. This result lead to the conclusion that the protein was not forming a simple monolayer. However, the thickness of the avidin layer could not be determined directly, but only after shifting of protein by the tip of the AFM leading to grooves of 1 ?m2 and -3 nm depth. As the height of oxide particles forming the waveguide surface was also in the range of 1.5 nm, the depth of these grooves could also be a result of the deposition of proteins on top of the oxide particles. This was consistent with the increased roughness of the surface after protein binding. Thus, investigations with the grating coupler were used to determine quantitatively the amount of immobilized avidin. On a biotinylated surface the amount of immobilized avidin lead to the assumption of a complete monolayer, whereas simple adsorption proved to be less efficient. A binding ratio of 1:1.3 for avidin and a biotinylated oligonucleotide was achieved. Up to 83% of the bound single strand were accessible for a subsequent hybridization reaction with a 12-mer. These results supported the model of avidin being deposited mainly on top of the oxide particles leading to the picture of a 'rough' complete protein monolayer, which was postulated from the AFM investigations.

Application of cellular automata simulation to truss structure design

2010-11-17T16:09:00Z

In the cellular automata simulation, the object under consideration is divided into small cells and the simulation is performed according to the local rule which is defined as the local relationship among cells. In this paper, the concept of cellular automata is applied to the design scheme of truss structures. First, truss elements are considered as the cells of the cellular automata and the local rule is derived from the optimization problem. The objective functions are defined to minimize the total weight of the structure and to obtain even stress distribution in the whole structure. The constraint conditions are introduced in order to define the local rule. The present method is applied to the design of the plane and the three-dimensional truss structures such as Schwedler and Lamella Domes. The convergence histories of the total weight and the mean and the maximum stresses are shown in order to discuss the property of the present method.

Application of Clegg impact value for the evaluation of the properties of asphalt concrete

Paranavithana, S og Mohajerani, A — 2010-03-10T00:00:00Z

The Clegg impact hammer is used to obtain a parameter relating to strength or stiffness of soil or similar type of materials. Tha parameter obtained is called the Clegg impact value(CIV). This study has investigated the relationship between CIV and bitument content in a compacted bituminous concrete and the possible application of CIV for the evaluation of the properties of asphalt concrete. It was found that the CIV of compacted asphalt increases to a maximum value and decreases with an increase in bitument content. This relationship was similar to the stability versus bitumen content relationship detemined in the Marshall method of mix design. Optimum binder contents determined using CIV, air voids and bulk density were comparable with those values determined using the standard Marshall method and the Austroads Pavement Research Group method.

Application of comprehensive two-dimensional gas chromatography (GCxGC) to the enantioselective analysis of essential oils

Shellie, R og Marriott, P og Cornwall, C — 2009-12-09T00:00:00Z

A new method for the enantioselective analysis of essential oils is described, using comprehensive two-dimensional gas chromatography (GC�GC). The column set comprised a primary column containing a cyclodextrin derivative as a chiral selector, and a secondary column containing a polyethylene glycol stationary phase. A cryogenic modulation system was used to achieve the GC�GC experiment. The enantiomeric compositions of a number of monoterpene hydrocarbons and oxygenated monoterpenes in Australian tea tree (Melaleuca alternifolia), including -thujene, sabinene, -pinene, -phellandrene, limonene, trans-sabinene hydrate, cis-sabinene hydrate, linalool, terpinen-4-ol, and -terpineol are reported. The GC�GC resolution advantage is shown to improve the efficiency of enantioselective essential oil analyses. In a single temperature programmed analysis, the individual antipodes of optically active components can be separated, and are effectively free from matrix interferences.

Application of comprehensive two-dimensional gas chromatography to drugs analysis in doping control

Kueh, A og Marriott, P — 2010-04-01T10:13:05Z

Comprehensive two-dimensional gas chromatography (GC×GC) now occupies a niche within the GC technology regime. The technique is undeniably unique in the manner in which the experiment is conducted, the way results are presented and the interpretive opportunities offered. For the 1000th volume of this journal it is appropriate to expand upon these features, and review the progress made in GC×GC to date. Firstly, brief general comment is made on multidimensional procedures, and to review key aspects of GC×GC. The use of the targeted multidimensional GC method allows absolute retentions in the second dimension of a GC×GC experiment to be estimated, and also offers a novel way to obtain enhanced response for resolved solutes. Then, to illustrate the utility of the technique, the application of GC×GC to the screening of drugs and their metabolites in biological fluids is described using prolintane metabolites in canine urine as an example, with samples taken at four time intervals after administration. This example illustrates the first application of GC×GC in the field of forensic toxicology, an area traditionally dominated by GC-MS. Most drug compounds were found to be retained on the 0.8-m second column for a greater time than the modulation period (3 s) used for initial analysis, under the conditions described. Hence a 0.4-m D2 BPX50 (50% phenyl methyl polysilphenylene) column was then used throughout, with most compounds retained less than 4 s. For the standard drug mixture, three overlapping drugs on the first dimension column (BPX5) were subsequently baseline resolved on the BPX50 column. For prolintane administration samples, the parent drug and metabolites could be effectively resolved from background matrix peaks. Likewise a 23-drug spike standard in horse urine blank gave acceptable resolution of the drugs from matrix peaks.

Application of comprehensive two-dimensional gas chromatography to sterols analysis

2009-09-01T00:00:00Z

The applicability of comprehensive two-dimensional gas chromatography (GC�GC) for sterol analysis was investigated by separation and identification of endogenous sterols in standards, and spiked in human urine. The modulation temperature was optimized to achieve the best separation and signal enhancement. The separation pattern of trimethylsilyl (TMS) derivatives of sterols was compared on two complementary column sets. Whilst the BPX5/BPX50 column set offers better overall separation, BPX50/BPX5 provides better peak shape and sensitivity. Comparison of the identification power of GC�GC--TOFMS against both the NIST05 MS library and a laboratory created (in-house) TOFMS library was carried out on a free sterols extract of urine, derivatised and spiked at the World Anti-Doping Agency (WADA) limit of 2 ng mL-1. The average match quality for 19 analysed sterols on the BPX50/BPX5 column set was 950/1000 when searched against the in-house library; only four were identified against the NIST05 library, at a match threshold of 800. The match quality of GC�GC--TOFMS spectra was superior to that for analysis using 1D GC--TOFMS for sterols spiked in urine at 10 ng mL-1. An r2 > 0.997 was obtained for the concentration range between 0.25 ng mL-1 and 10 ng mL-1 for three selected sterols. The lowest limit of detection (LOD) was obtained for estrone (0.1 ng mL-1) and the highest LOD was for 5a-androstan-3a,11�-diol-17-one, epitestosterone and cholesteryl butyrate (1 ng mL-1), using a match threshold of at least 800 and signal-to-noise ratio of at least 10. TOFMS coupled to GC�GC enabled satisfactory identification of sterols in urine at their LOD. A minimum acceptable match (MAM) criterion for urinary sterols using 2D retention times and TOF mass spectra is introduced. This study shows that GC�GC--TOFMS yields high specificity for steroids derived from urine, with detection limits appropriate for use in doping control.

Application of comprehensive two-dimensional gas chromatography to the quantification of overlapping faecal sterols

2010-04-01T10:13:05Z

Standard solutions containing a mixture of seven sterols and 5[alpha]-cholestane as internal standard, and sample mixtures that comprised varying ratios of sterol and stanols from green lip mussel tissue and dried cow faeces were analysed by using comprehensive two-dimensional gas chromatography (GC×GC). Quantitative results were compared with single-column GC analysis. The latter samples included sterols of interest, but which cannot be readily obtained elsewhere. It may also mimic potential environmental samples where dairy production and aquaculture (oyster, mussel cultivation) share the same catchment; environmental sterol signatures may exhibit characteristics of both sample types comprising this mixture. Whereas single-column GC-flame ionisation detection was unable to reliably quantitate target sterols, the GC×GC experiment permitted small amounts of sterols and stanols to be detected and separated. Likewise GC-MS analysis was unable to detect some of the minor sterols which coeluted on a single column. The GC×GC mode allows complete separation of several important sterols and stanols, such as 24-ethylcoprostanol, campesterol and 24-methylenecholesterol, demonstrating the enhanced resolving power of the GC×GC system. Separation of 24-ethyl-epi-coprostanol from several algal-derived interfering components was achieved, leading to higher degree of confidence in the quantitative analysis of faecal sterols. The effects of a number of operating variables--column length, carrier flow-rate and elution temperature--on component resolution and presentation of data in the two-column analysis are described.

Application of comprehensive two-dimensional gas chromatography with nitrogen-selective detection for the analysis of fungicide residues in vegetable samples

2009-02-18T09:53:18Z

Comprehensive two-dimensional gas chromatography (GCxGC) with nitrogen-phosphorus detection (NPD) has been investigated for the separation and quantitation of fungicides in vegetable samples. The detector gas flows (H-2, N-2 and air) were adjusted to achieve maximum response of signal whilst minimizing peak width. The comparison of different column sets and selection of the temperature program were carried out with a mixture of nine N-containing standard fungicides, eight of which were chlorinated. The results from GCxGC-NPD and GCxGC with micro electron-capture detection (mu ECD) were compared. External calibrations of fungicides were performed over a concentration range from I to 1000 mu g L-1. The peak area calibration curves generally had regression coefficients of R-2 > 0.9980, however for iprodione which was observed to undergo on-column degradation, an R-2 of 0.990 was found. The limit of detection (LOD) and limit of quantitation (LOQ) were less than about 74 and 246 ng L-1, respectively. The intra-day and inter-day RSD values were measured for solutions of concentration 0.100, 0.500 and 1.50 mg L-1. For the 0.500 mg L-1 solution, intra- and inter-day precision of peak area and peak height for most of the pesticides were about 2% and 8%, respectively. Excellent linearity was observed for these standards, from 0.001 to 25.00 mg L-1. The standard mixture peak positions were identified by using GCxGC with quadrupole mass spectrometry (qMS). To illustrate the potential and the versatility of both GCxGC-NPD and GCxGC-mu ECD, the method was applied to determination of fungicides in a vegetable extract. Decomposition of one fungicide standard (iprodione) during chromatography elation was readily observed in the two-dimensional (2D) GCxGC plot as a diagonal ridge response in the 2D chromatogram between the degrading compound and the decomposition product.

Application of dry film resist in the fabrication of microfluidic chips for droplet generation

Leech, P og Wu, N og Zhu, Y — 2011-11-04T00:00:00Z

The combined use of film transparency masks and dry laminar resist (Shipley 5038) has enabled the rapid fabrication of prototype devices for droplet generation. The resolution limit of structures in the resist was controlled by the type of mask (transparency or electron beam Cr mask), the density of the pattern in transparency masks (2400 or 5080 dpi) and the thickness of the resist in the range of 35-140 ?m. Flow-focusing devices with master patterns based on dry film resist were replicated as a Ni shim and hot embossed into Plexiglas 99524. These devices were used to generate oil/water droplets with a well-defined dependence of diameter and frequency on the flow parameters.

Application of expert systems to aircraft accident investigation

Milosovski, G og Bil, C og Cosevski, M — 2010-11-17T16:09:00Z

In the last few decades there has been a considerable growth in the development of scientific methodologies for investigating complex issues, such as aircraft accidents, in order to establish a set of priorities for possible and desirable improvements. The essence of these methodologies is that they provide the optimal decision with respect to these priorities, which is based on information available, the strategic objectives and prediction of the future issues to be considered. An interdisciplinary approach and intuition have shown to be vital elements in developing contemporary methods for creating strategic decisions. A number of intuitive methods have been developed over the past few decades. One of the most successful among these methods is the Delphi technique. This paper discusses the application of the Delphi technique with respect to improving of aircraft accident investigation, in particular the stages of aircraft accident investigation where significant improvements can be made by contemporary technology and science. This paper provides the results of a qualitative and quantitative analysis of influential factors that have an impact on investigation outcomes. Furthermore, this paper addresses the requirement for a tool, which will be able to capture and store specific knowledge and analytical skills of a large number of experts. The paper discusses how aircraft accident investigation can be improved with the application of a global expert system as a tool for storing and analysing the forensic data of aircraft accidents worldwide.

Application of flow cytometry to platelet disorders

2011-11-25T00:00:00Z

Flow cytometry is a powerful and versatile tool that can be used to yield definitive information regarding the phenotypic status of platelets. The method provides a quantitative assessment of the physical and antigenic properties of platelets (e.g., surface expression of receptors, bound ligands, components of granules, or interactions of platelets with other platelets, other blood cells, or components of the plasma coagulation system), thereby facilitating the diagnosis of inherited or acquired platelet disorders (e.g., Bernard-Soulier syndrome, Glanzmann thrombasthenia, storage pool disease), the pathological activation of platelets (e.g., in the setting of acute coronary syndromes, cerebrovascular ischemia, peripheral vascular disease, cardiopulmonary bypass), and changes in the ability of platelets to activate via specific stimuli (e.g., efficacy of antiplatelet therapies). Accordingly, this review summarizes the key technical and methodologic components of flow cytometric analysis of platelets, as well as specific examples of its application to diagnosis and patient care.

Application of flow cytometry to platelet disorders

2010-12-06T00:00:00Z

Application of Gaschutz Theorem to relative difference sets in non-abelian groups

Galati, J — 2010-04-01T10:13:05Z

Let G be a finite group other than 4 and suppose that G contains a semiregular relative difference set (RDS) relative to a central subgroup U. We apply Gaschütz' Theorem from finite group theory to show that if G/U has cyclic Sylow subgroups for each prime divisor of |U|, then G splits over U. A corollary of this result is that a finite group (other than 4) in which all Sylow subgroups are cyclic cannot contain a central semiregular RDS. We also include an example, originally discovered by D.L. Flannery, which shows that our main theorem is not true in general when U is a (not necessarily central) abelian normal subgroup of G.

Application of GC-MS metabolic profiling to 'blue-green water' from microbial influenced corrosion in copper pipes

Beale, D og Dunn, M og Marney, D — 2010-11-17T00:00:00Z

This paper presents a novel application of fluorescence spectroscopy and gas chromatography-mass spectrometry (GC-MS) to water samples exposed to copper piping which had undergone some degree of microbial influenced corrosion. Using 3D fluorescence spectroscopy we were able to observe the `protein-like' fluorophore associated with presence of bacteria, and cross reference this with derivatized fatty acid metabolites determined via GC-MS analyses of the same sample. This methodology can be used as a simple screening tool to establish the presence or otherwise of microbial processes in waters, and correlation of specific metabolite profiles with different microbes will further enhance the utility of this tool.

Application of headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography (GC x GC) for the chemical profiling of volatile oils in complex herbal mixtures

2009-02-18T09:53:18Z

The coupling of headspace solid-phase microextraction (HS-SPME) with comprehensive two-dimensional gas chromatography (GC x GC) was shown to be a powerful technique for the rapid sampling and analysis of volatile oils in complex herbal materials. When compared to one-dimensional (1-D) GC, the improved analytical capabilities of GC x GC in terms of increased detection sensitivity and separation power were demonstrated by using HS-SPME/GC x GC for the chemical profiling (fingerprinting) of essential/volatile oils contained in herbal materials of increasing analytical complexity. More than 20 marker compounds belonging to Panax quinquefolius (American ginseng) can be observed within the 2-D contour plots of ginseng itself, a mixture of ginseng and another important herb (P. quinquefolius/Radix angelicae sinensis), as well as a mixture of ginseng and three other herbs (P. quinquefolius /R. angelicae sinensis/R. astragali/R. rehmanniae preparata). Such analytical capabilities should be important towards the authentication and quality control of herbal products, which are receiving increasing attention as alternative medicines worldwide. In particular, the presence of Panax in the herb formulation could be readily identified through its specific peak pattern in the 2-D GC x GC plot.

Application of HPLC-NMR for the rapid chemical profiling of a Southern Australian Sponge, Dactylospongia sp

Dias, D og Urban, S — 2009-11-18T17:19:34Z

Rapid chemical profiling of the antitumour active crude dichloromethane extract of the marine sponge, Dactylospongia sp. was undertaken. A combination of both offline (HPLC followed by NMR and MS) and on-line (on-flow and stop-flow HPLC-NMR) chemical profiling approaches was adopted to establish the exact nature of the major constituents present in the dichloromethane extract of this sponge. On-flow HPLC-NMR analysis was employed to initially identify components present in the dichloromethane extract, while stop-flow HPLC-NMR experiments were then conducted on the major component present, resulting in the partial identification of pentaprenylated p-quinol (5). Subsequent off-line RP semi-preparative HPLC isolation of 5 followed by detailed spectroscopic analysis using NMR and MS permitted the complete structure to be established. This included the first complete carbon NMR chemical shift assignment of 5 based on the heteronuclear 2-D NMR experiments, together with the first report of its antitumour activity. This study represents one of the few reports describing the application of HPLC-NMR to chemically profile secondary metabolites from a marine organism.

Application of HPLC-NMR in the identification of plocamenone and isoplocamenone from the marine red alga Plocamium angustum

Timmers, M og Dias, D og Urban, S — 2013-04-23T13:31:00Z

A combination of on-line HPLC-NMR and off-line chemical investigations has resulted in the identification of the previously reported polyhalogenated monoterpene plocamenone, together with the new structural analogue isoplocamenone from the crude extract of the marine alga Plocamium angustum. On-flow and stop-flow HPLC-NMR analyses (including the acquisition of WET 2D NMR spectra) rapidly assisted in the identification of the major component plocamenone and in the partial identification of its unstable double bond isomer isoplocamenone. Conventional off-line isolation and structural characterization techniques were employed to unequivocally confirm both structures, leading to a structural revision for plocamenone, as well as to obtain sufficient quantities for biological testing.

Application of mechanism-based CYP inhibition for predicting drug-drug interactions

Zhou, Z og Zhou, S — 2010-05-25T10:50:25Z

BACKGROUND: A mechanism-based inhibition of CYPs is characterized by NADPH-, time- and concentration-dependent enzyme inactivation and substrate protection. A significant inactivation of CYPs and particularly the main human hepatic and intestinal CYPs could result in clinical drug-drug interactions (DDIs) and adverse drug reactions. OBJECTIVE: To address whether DDIs owing to mechanism-based CYP inhibition is predictable based on in vitro inhibitory data. METHOD: Medline (by means of PubMed up to 26 March 2009) has been searched using proper relevant terms. RESULT/CONCLUSION: It is possible to predict DDIs caused by mechanism-based CYP inhibition, although the in vitro data do not necessarily translate directly into relative extents of inhibition in vivo because in vivo clinical consequences depend on additional factors that are not easily accounted for in vitro and for reversible inhibition. Incorporation of other important parameters such as CYP degradation rate (k(deg)), relative contribution of the CYP inactivated to the victim drug elimination (f(m(CYP))) and inhibition of intestinal CYP-mediated first-pass metabolism of the object drug (F'(gut)/F(gut) ratio) into the prediction models significantly improves the prediction. Uncertainty of the prediction is mainly from the variability in the estimates of these critical parameters.

Application of method of false transients to generate smooth grids around a body in motion

Ly, E og Norrison, D — 2010-12-22T00:00:00Z

A time marching finite difference scheme incorporating an efficient method of false transients, an approximate factorisation technique and a time steps cycling process, is presented for solution of a system of Poisson's equations. The solution to the equations provides a smooth three dimensional boundary fitted grid around a body in motion. The scheme required much less computational effort than that required by other iterative schemes. In closure, examples of a static grid around an aircraft tailplane and a dynamic grid grid around an aircraft tailplane and a dynamic grid around an aircraft tailplane and a dynamic grid around a flapping wing are presented.

Application of microscale-preparative multidimensional gas chromatography with nuclear magnetic resonance spectroscopy for identification of pure methylnaphthalenes from crude oils

2010-12-06T00:00:00Z

Mass spectrometry is often insufficient to distinguish between structural isomers, requiring confirmation using NMR spectroscopy. Here, a novel preparative technique based upon capillary multidimensional gas chromatography to isolate pure volatile components from complex samples is described. The method was developed through isolation of 1,4-dimethoxybenzene (5.2 ?g, 10 injections) from a peppermint essential oil. Then isomers of 1- and 2-methylnaphthalene were isolated from a complex crude oil in sufficient amounts (3.1 ?g, 38 injections and 5.0 ?g, 35 injections) for discrimination using 1H NMR spectroscopy. This methodology is applicable to identify any volatile molecule in complex matrices requiring confirmation using NMR spectroscopy.

Application of multi-agent technology to information systems: An agent-based design architecture for decision support systems

2010-12-13T00:00:00Z

One of the most difficult issues in building efficient Information Systems (IS) is the integration of these systems with the organization's other systems. This issue is particularly acute for Decision Support Systems (DSSs). To become more effective and efficient, a DSS must have an open structure to adapt to the dynamic environment. However, current IS, especially DSSs, tend to rely excessively on traditional System Development Life Cycle (SDLC) and this places limitations on current systems' infrastructures. The emergence of multi-agent technology addresses this issue and its applications to IS are becoming highly efficient. In this paper, we introduce a Matrix-Agent connection design, called Agent based Open Connectivity for Decision Support Systems (AOCD), which balances the manageability and flexibility in a system and maximizes system performance.

Application of numerical basis sets to hydrogen bonded systems: A density functional theory study

2009-02-18T00:00:00Z

We have investigated and compared the ability of numerical and Gaussian-type basis sets to accurately describe the geometries and binding energies of a selection of hydrogen bonded systems that are well studied theoretically and experimentally. The numerical basis sets produced accurate results for geometric parameters but tended to overestimate binding energies. However, a comparison of the time taken to optimize phosphinic acid dimer, the largest complex considered in this study, shows that calculations using numerical basis sets offer a definitive advantage where geometry optimization of large systems is required.

Application of optical trapping to beam manipulation in optofluidics

2009-02-18T00:00:00Z

We introduce a novel method of attaining all-optical beam control in an optofluidic device by displacing an optically trapped microsphere though a light beam. The micro-sphere causes the beam to be refracted by various degrees as a function of the sphere position, providing tunable attenuation and beam-steering in the device. The device itself consists of the manipulated light beam extending between two buried waveguides which are on either side of a microfluidic channel. This channel contains the micro-spheres which are suspended in water. We simulate this geometry using the Finite Difference Time Domain method and find good agreement between simulation and experiment.

Application of probabilistic neural networks in modelling structural deterioration of stormwater pipes

2013-02-19T13:10:00Z

In Australia, when stormwater systems were ﬁrst introduced over 100 years ago, they were constructed independently of the sewer systems, and they are normally the responsibility of the third level of government, i.e., local government or city councils. Because of the increasing age of these stormwater systems and their worsening performance, there are serious concerns in a signiﬁcant number of city councils regarding their deterioration. A study has been conducted on the structural deterioration of concrete pipes that make up the bulk of the stormwater pipe systems in these councils. In an attempt to look for a reliable deterioration model, a probabilistic neural network (PNN) model was developed using the data set supplied from participating councils. The PNN model was validated with snapshot-based sample data, which makes up the data set. The predictive performance of the PNN model was compared with a traditional parametric model using discriminant analysis on the same data set. Structural deterioration was hypothesised to be inﬂuenced by a set of explanatory factors, including pipe design and construction factors—such as pipe size, buried depth—and site factors— such as soil type, moisture index, tree root intrusion, etc. The results show that the PNN model has a better predictive power and uses signiﬁcantly more input variables (i.e., explanatory factors) than the discriminant model. More importantly, the key factors for prediction in the PNN model are diﬃcult to interpret, suggesting that besides prediction accuracy, model interpretation is an important issue for further investigation.

Application of pseudospectral methods for receding horizon control

Williams, P — 2010-12-06T00:00:00Z

A pseudospectral method for solving nonlinear receding-horizon control problems is presented. The method depends on solutions of simultaneous linear equations. The algorithm is demonstrated to be practical for online implementation in a tether system. The closed-loop performance is found to be excellent in the face of unmodeled disturbances due to tether mass and flexibility.

Application of pulsed electric field in non-thermal processing of milk

Shamsi, K og Sherkat, F — 2010-12-22T00:00:00Z

Pulsed electric field (PEF) is an innovative non-thermal technology which could be used as an alternative to the traditional thermal process to inactivate the microorganisms and enzymes in liquid foods such as milk. Compared to thermal processing, the PEF process is considered more energy efficient as the microbial or enzymatic inactivation is achieved at ambient or mild temperatures by the application of short bursts of high intensity electric fields to liquid food flowing between two electrodes. Extensive international research has been conducted since the 1990s on the development of PEF in the food industry. This article reviews the recent findings on the application of PEF technology in milk processing, the mechanisms and factors affecting microbial and enzymatic inactivation by PEF treatment and the application of PEF in combination with antimicrobials.

Application of safranine O optical detector in environmental and food analysis

Kazemzadeh, A og Amin, M — 2011-12-01T00:00:00Z

The work presented here describes the oxalic acid detector was developed by immobilizing a direct indicator dye in an optical detecting film for food and environmental monitoring. This detector was fabricated by binding sarfranine O to a cellulose acetate film that had previously been subjected to an exhaustive base hydrolysis. The membrane has good durability (> 8 months) and a short response time (< 10 s). Oxalic acid can be determined for the range 0.15-6.50 �g mL-1 with 3s detection limits of 60 ng mL-1. The method is easy to perform and uses acetylcellulose as a carrier. The reagents used for activating the cellulose support are inexpensive, non-toxic and widely available.

Application of Taguchi method in optimization of cervical ring cage

Yang, K og Teo, E og Fuss, F — 2010-11-17T16:09:00Z

The Taguchi method is a statistical approach to overcome the limitation of the factorial and fractional factorial experiments by simplifying and standardizing the fractional factorial design. The objective of the current study is to illustrate the procedures and strengths of the Taguchi method in biomechanical analysis by using a case study of a cervical ring cage optimization. A threedimensional finite element (FE) model of C5-C6 with a generic cervical ring cage inserted was modelled. Taguchi method was applied in the optimization of the cervical ring cage in material property and dimensions for producing the lowest stress on the endplate to reduce the risk of cage subsidence, as in the following steps: (1) establishment of objective function; (2) determination of controllable factors and their levels; (3) identification of uncontrollable factors and test conditions; (4) design of Taguchi crossed array layout; (5) execution of experiments according to trial conditions; (6) analysis of results; (7) determination of optimal run; (8) confirmation of optimum run. The results showed that a cage with larger width, depth and wall thickness can produce the lower von Mises stress under various conditions. The contribution of implant materials is found trivial. The current case study illustrates that the strengths of the Taguchi method lie in (1) consistency in experimental design and analysis; (2) reduction of time and cost of experiments; (3) robustness of performance with removing the noise factors. The Taguchi method will have a great potential application in biomechanical field when factors of the issues are at discrete level.

Application of the constrained fluid lambda-integration path to the calculation of high temperature Au(110) surface free energies

Grochola, G og Snook, I og Russo, S — 2009-02-18T09:53:18Z

Recently a method termed constrained fluid lambda-integration was proposed for calculating the free energy difference between bulk solid and liquid reference states via the construction of a reversible thermodynamic integration path; coupling the two states in question. The present work shows how the application of the constrained fluid lambda-integration concept to solid/liquid slab simulation cells makes possible a generally applicable computer simulation methodology for calculating the free energy of any surface and/or surface defect structure, including surfaces requiring variations in surface atom or density number, such as the (1x5) Au(100) or (1x2) missing row Au(110) reconstructed surfaces or excess adatom/vacancy/step populated surfaces. We evaluate the methodology by calculating the free energy of various disordered high temperature Au(110) embedded atom method surfaces constrained to differing excess surface atom numbers [including those corresponding to the (1x2) missing row reconstructed surface] and obtained the interesting result that at 1000 K (as distinct from lower temperatures) the free energy difference between these surfaces is reduced to zero; a result which is consistent with an expected order-disorder phase transition for the Au(110) surface at such high temperatures.

Application of the inverse analysis to the dynamic response test of structures subjected to intense dynamic loading

Lu, J og Shen, J og Zhao, L — 2013-02-19T13:10:00Z

The impact force time history of structures subjected to intense dynamic loading is one of the most important parameters measured. It is difficult to measure the contact force directly. In order to overcome the difficulties, the inverse analysis has been developed during recent years. This paper presents the application of the inverse analysis to the dynamic response test of pressure pipeline subjected to intense dynamic loading laterally. The transfer function h(t) is given by using computer simulation. The experimental data is justified, and more accuracy impact force history is obtained.

Application of the Morris algorithm for sensitivity analysis if the REALM model for the Goulburn Irrigation System

Schreider, S og Braddock, R — 2009-02-18T09:53:18Z

The REALM modelling shell is widely used in Australia as a water allocation modelling tool. It has been used to develop the Goulburn System Model (GSM) of the Goulburn, Broken, Loddon and Campaspe Rivers in northeastern Victoria. REALM represents the river and irrigation system as a network of storages and carriers. The model has been optimised to best represent the water harvesting and allocation for use by water management authorities. The model is analysed to assess the sensitivity of a subset of the model outputs, to a subset of the system parameters. The New Morris algorithm uses sampling paths generated in the space of the parameters, to generate points at which the model is run (to generate the model outputs). These model runs are then used to estimate the first and second-order effects of the parameters on the outputs. The results illustrate the mild linkage of the Goulburn and Broken systems, and the Broken system also shows differences between minimum and average outflows. The Goulburn is more sensitive to some of the numerical convergence parameters used in the allocation software, while the Broken is less sensitive to these factors. The numerical convergence factors also lead to important second-order effects.

Application of the synthetic polymer approach to the glass transition of fruit leathers

2010-12-22T10:15:00Z

A commercial fruit leather was analysed in an effort to document the application of the synthetic polymer approach to its vitrification properties. Techniques employed were dynamic mechanical thermal analysis on tension and modulated differential scanning calorimetry. The temperature and frequency dependence of Young's modulus were utilized in the construction of composite curves of viscoelasticity that identified the rubbery plateau, glass transition region and glassy state. The painstaking investigation of viscoelasticity supported by the combined framework of WLF/free-volume theory was successful in identifying the mechanical Tg of the partially vitreous material at subzero temperatures. That was contrasted with the corresponding value obtained using calorimetry, and the nature of the discrepancy between the two estimates of Tg was discussed.

Application of the theory of planned behaviour to predict pro-tourism attitude in differing rural community segments inside regional Victoria, Australia. A hierarchical regression analysis.

Inbakaran, R og Jackson, M og Zhang, J — 2010-12-22T00:00:00Z

Application of variable selection techniques to a modified SAIS for generating practical scorecards

2010-11-17T16:09:00Z

Selecting better predictive variables is fundamental for scorecards to perform well. This study makes use of a large credit scoring dataset and investigates the application of several variable selection techniques for scorecard development. The scorecards are developed using a statistical technique (logistic regression) and two AI methods (SAIS and AIRS). SAIS, which we previously developed can predict class outcomes accurately and has good classification accuracy which is the percentage of correctly classified data. However, since an unbalanced dataset was obtained, the Gini coefficient which is the main performance measure used in industry and which is insensitive to changes in class distribution needs be used instead. SAIS is modified to generate a Gini coefficient and an investigation of its suitability for practical scorecard development is made. We found that further modifications are needed in order for it to perform as well as logistic regression. Moreover, among the different variable selection techniques used, stepwise regression was found to perform best.

Application of Wool in High-velocity Ballistic Protective Fabrics

Kanesalingam, S og Arnold, L og Padhye, R — 2010-11-17T00:00:00Z

The protective power of typical aramid-based ballistic fabrics, when assembled into multi-layered panels designed to defeat high-velocity ballistic impacts, can be improved if wool is incorporated into the weave structure. Although the synthetic is still the primary energy-absorbent material, the wool plays a complementary role by increasing resistive interactions between the yarns and filaments. Wool restricts the lateral separation of the synthetic yarns and ensures that more directly impacted yarns are held in place to dissipate the impact energy. Wool increases the energy-absorption mechanism of yarn pull-in by increasing the longitudinal friction along the yarns/filaments, in particular near the free edges of the fabric layers. The wool absorbs water that may otherwise lubricate synthetic filaments and so improves the wet performance. Ballistics tests have shown that synthetic fabrics blended with wool can at least match the dry or wet ballistic performance of an equivalent pure Kevlar fabric when tested under National Institute of Justice (NIJ) Ballistic Standard Level III A. The inclusion of the wool can significantly improve the tear strength of pure synthetic ballistic fabrics.

Application of wool in high-velocity ballistic protective fabrics

Kanesalingam, S og Arnold, L og Padhye, R — 2010-12-06T14:11:00Z

Applications of comprehensive two-dimensional gas chromatography to the characterization of petrochemical and related samples

2009-02-18T09:53:18Z

This article discusses the application of comprehensive two-dimensional gas chromatography (GC x GC) to samples derived from petrochemicals. The use of GC x GC for characterization of petroleum and petroleum derivatives, through group type analysis, such as benzene, toluene, ethylbenzene, xylenes (BTEX), total aromatic hydrocarbons, polyaromatic hydrocarbons, and heteroatomic sulfur-, oxygen-, and nitrogen-containing compounds is presented. The capability of GC x GC to provide additional chemical-specific information regarding petroleum-processing steps, such as linear alkanes dehydrogenation, Fischer-Tropsch process, hydrogenation and oligomerization, is also described. In addition, GC x GC analyses of petrochemical biomarkers and environmental petrochemical-derived pollutants are reported. The role of comparison of samples through use of simple fingerprint approaches is highlighted.