1,125 research outputs found
Flow impacts on estuarine finfish fisheries of the Gulf of Carpentaria
The estuaries of Australia s tropical rivers support commercial fisheries for finfish and shellfish valued at over $220 million per annum. There are also significant tourism-related and local recreational and indigenous fisheries for icon species such as barramundi. Development of water resources in Australia's Tropical Rivers region is being considered for the Flinders, Mitchell, McArthur, Roper, Daly and Victoria catchments. Greater knowledge of the freshwater requirements of tropical aquatic ecosystems, including estuaries is crucial, so that the communities of catchments where water resource development occurs can be assured that the downstream effects of such development are considered and managed based on the best available knowledge
Characteristics of individuals presenting to treatment for primary alcohol problems versus other drug problems in the Australian patient pathways study
Background: People seeking treatment for substance use disorders often have additional health and social issues.
Although individuals presenting with alcohol as the primary drug of concern (PDOC) account for nearly half of all
treatment episodes to the Australian alcohol and other drug (AOD) service system, previous treatment cohort
studies have focused only on the profile of Australian heroin or methamphetamine users. While studies overseas
indicate that clients seeking treatment primarily for their drinking are less likely to experience social and economic
marginalisation than those seeking treatment primarily for illicit or pharmaceutical drug use, very little research has
directly compared individuals presenting with alcohol as the PDOC to those primarily presenting with other drugs
as their PDOC.
Methods: Seven hundred and ninety-six participants were recruited at entry to specialist AOD treatment in Victoria
and Western Australia, and completed measures of demographic and social factors, substance use, quality of life,
service use, and criminal justice involvement. We compared those with alcohol as their PDOC to those with other
drugs as their PDOC using Pearson chi-square and Mann–Whitney U tests.
Results: Rates of social disadvantage, poor quality of life, high severity of substance dependence, and past-year
AOD, mental health, acute health, and social service use were high in all groups. However, participants with alcohol as
the PDOC were older; more likely to have an educational qualification; less likely to report criminal justice involvement,
housing/homelessness service use, tobacco smoking, or problems with multiple substances; and reported better
environmental quality of life; but were more likely to have used ambulance services, than those with other drugs
as their PDOC.
Conclusions: While those seeking treatment primarily for alcohol problems appear less likely to suffer some forms of
social and economic disadvantage or to use multiple substances than those with a primary drug problem, they
experience similarly high levels of substance dependence severity and mental health and AOD service use. These
findings reinforce the need for AOD services to integrate or coordinate care with programs that address the many
complexities clients frequently present with, while also acknowledging differences between those seeking treatment
for alcohol versus other drug problems
Large-Scale Experiments On Tsunami Inundation And Overtopping Forces At Vertical Sea Walls
Tsunami are very long gravity waves that may cause significant damage to coastal sea walls. The majority of relevant design codes and research papers that describe methods for predicting tsunami loads on coastal walls consider the scenario of transitory force from a bore-led wave. This does not relate to tsunami that do not form bore waves. Bore fronts generally cause short term spikes in force, which may have little effect on the vulnerability of massive structures. Post disaster accounts suggest that most coastal walls show damage that implies failure modes that occur over moderate to long durations. Therefore it is likely that the bore front assumption gives an overly conservative prediction of maximum force, and may not capture the full timescale of tsunami loading. This paper uses a pneumatic tsunami generation facility to determine the force loading on two vertical coastal sea walls during tsunami inundation. Two sea-wall models, 0.15 and 0.25 m high, with crown widths of 0.1 m (7.5 and 12.5 m at a nominal prototype scale of 1:50) are tested. It is shown that bore fronts only occur for short period waves over the bathymetry tested. Bore fronts cause a very short period spike in force, which is followed by a transitory force approximated by the hydrostatic pressure equation. The loading of tsunami length waves of periods 40 s (280 s prototype at 1:50 scale), which do not break is not greater than 1.2 times the hydrostatic force. Overtopping volume is positively correlated to the time duration of positive upstream head over the crest, rather than its maximum value. Overtopping causes a small increase in the horizontal load due to the addition of a drag and momentum load. The magnitude and time of these effects are small and short-lived in comparison to the hydrostatic load. The results compare well with available equations based on hydrostatic force and the engineer may apply a desired multiplying coefficient of a factor of at least 1.2 to account for any added pressure and momentum, and the factor of safety intended
Formation of a ZnS Zn S,O bilayer buffer on CuInS2 thin film solar cell absorbers by chemical bath deposition
The application of Zn compounds as buffer layers was recently extended to wide gap CuInS2 CIS based thin film solar cells. Using a new chemical deposition route for the buffer preparation aiming at the deposition of a single layer, nominal ZnS buffer without the need for any toxic reactants such as, e.g. hydrazine, has helped to achieve a similar efficiency as respective CdS buffered reference devices. In order to shed light on the differences of other Zn compound buffers deposited in conventional chemical baths CBD compared to the buffer layers deposited by this alternative CBD process, the composition of the deposited buffers was investigated by x ray excited Auger electron and x ray photoelectron spectroscopy to potentially clarify their superiority in terms of device performance. We have found that in the early stages of this alternative CBD process a thin ZnS layer is formed on the CIS, whereas in the second half of the CBD the growth rate is greatly increased and Zn S,O with a ZnS ZnS ZnO ratio of approx. 80 is deposited. Thus, a ZnS Zn S,O bi layer buffer is deposited on the CIS thin film solar cell absorbers by the alternative chemical deposition route used in this investigation. No major changes of these findings after a postannealing of the buffer CIS sample series and re characterization could be identified
Clinical trials of medicinal cannabis for appetite-related symptoms from advanced cancer: a survey of preferences, attitudes and beliefs among patients willing to consider participation
© 2016 Royal Australasian College of Physicians Background: Australian clinical trials are planned to evaluate medicinal cannabis in a range of clinical contexts. Aims: To explore the preferences, attitudes and beliefs of patients eligible and willing to consider participation in a clinical trial of medicinal cannabis for poor appetite and appetite-related symptoms from advanced cancer. Methods: A cross-sectional anonymous survey was administered from July to December 2015 online and in eight adult outpatient palliative care and/or cancer services. Respondents were eligible if they were ≥18 years, had advanced cancer and poor appetite/taste problems/weight loss and might consider participating in a medicinal cannabis trial. Survey items focused on medicinal rather than recreational cannabis use and did not specify botanical or pharmaceutical products. Items asked about previous medicinal cannabis use and preferences for delivery route and invited comments and concerns. Results: There were 204 survey respondents, of whom 26 (13%) reported prior medicinal cannabis use. Tablets/capsules were the preferred delivery mode (n = 144, 71%), followed by mouth spray (n = 84, 42%) and vaporiser (n = 83, 41%). Explanations for preferences (n = 134) most commonly cited convenience (n = 66; 49%). A total of 82% (n = 168) of respondents indicated that they had no trial-related concerns, but a small number volunteered concerns about adverse effects (n = 14) or wanted more information/advice (n = 8). Six respondents volunteered a belief that cannabis might cure cancer, while two wanted assurance of efficacy before participating in a trial. Conclusion: Justification of modes other than tablets/capsules and variable understanding about cannabis and trials will need addressing in trial-related information to optimise recruitment and ensure that consent is properly informed
Methane detection scheme based upon the changing optical constants of a zinc oxide/platinum matrix created by a redox reaction and their effect upon surface plasmons
We detect changes in the optical properties of a metal oxide semiconductor (MOS), ZnO, in a multi-thin-film matrix with platinum in the presence of the hydrocarbon gas methane. A limit of detection of 2% by volume with concentrations from 0 to 10% and maximum resolution of 0.15% with concentrations ranging from 30% to 80% at room temperature are demonstrated along with a selective chemical response to methane over carbon dioxide and the other alkane gases. The device yields the equivalent maximum bulk refractive index spectral sensitivity of 1.8 × 105 nm/RIU. This is the first time that the optical properties of MOS have been monitored to detect the presence of a specific gas. This single observation is a significant result, as MOS have a potentially large number of target gases, thus offering a new paradigm for gas sensing using MOSs
Research activities arising from the University of Kent
In this paper I describe research activities in the field of optical fiber sensing undertaken by me after leaving the Applied Optics Group at the University of Kent. The main topics covered are long period gratings, neural network based signal processing, plasmonic sensors, and polymer fiber gratings. I also give a summary of my two periods of research at the University of Kent, covering 1985–1988 and 1991–2001
Low-dimensional nano-patterned surface fabricated by direct-write UV-chemically induced geometric inscription technique
We investigate a nano-patterning process which creates reproducible periodic surface topological features that range in size from ~100 µm to ~20 µm . Specifically, we have fabricated multi-layered thin films consisting of germanium/silicon strata on a planar substrate, with each layer having nanometers thickness. The material processing exploits focused 244 nm ultra-violet laser light and an opto-mechanical setup typically applied to the inscription of fiber gratings, and is based upon the well-known material compaction interaction of ultra-violet light with germanium oxides. We show this process can be extended to create arrays of metal nano-antennas by adding a metal overlay to the thin film. This results in arrays with dimensions that span nanometer- to centimeter-length scales. Also, each nano-antenna consists of “nano-blocks.” Experimental data are presented that show the UV irradiance dosage used to create these metal nanostructures on D-shaped optical fibers has a direct relationship to their transmission spectral characteristics as plasmonic devices
Real-time kinetic binding studies at attomolar concentrations in solution phase using a single-stage opto-biosensing platform based upon infrared surface plasmons
Here we present a new generic opto-bio-sensing platform combining immobilised aptamers on an infrared plasmonic sensing device generated by nano-structured thin film that demonstrates amongst the highest index spectral sensitivities of any optical fibre sensor yielding on average 3.4 × 104 nm/RIU in the aqueous index regime (with a figure of merit of 330) This offers a single stage, solution phase, atto-molar detection capability, whilst delivering real-time data for kinetic studies in water-based chemistry. The sensing platform is based upon optical fibre and has the potential to be multiplexed and used in remote sensing applications. As an example of the highly versatile capabilities of aptamer based detection using our platform, purified thrombin is detected down to 50 attomolar concentration using a volume of 1mm3 of solution without the use of any form of enhancement technique. Moreover, the device can detect nanomolar levels of thrombin in a flow cell, in the presence of 4.5% w/v albumin solution. These results are important, covering all concentrations in the human thrombin generation curve, including the problematic initial phase. Finally, selectivity is confirmed using complementary and non-complementary DNA sequences that yield performances similar to those obtained with thrombin
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