923 resultados para large-mode-area
Resumo:
We demonstrate that a three dimensional (3D) crystalline tungsten trioxide (WO3) nanoporous network, directly grown on a transparent conductive oxide (TCO) substrate, is a suitable working electrode material for high performance electrochromic devices. This nanostructure, with achievable thicknesses of up to 2 μm, is prepared at room temperature by the electrochemical anodization of a RF-sputtered tungsten film deposited on a fluoride doped tin oxide (FTO) conductive glass, under low applied anodic voltages and mild chemical dissolution conditions. For the crystalline nanoporous network with thicknesses ranging from 0.6 to 1 μm, impressive coloration efficiencies of up to 141.5 cm2 C−1 are achieved by applying a low coloration voltage of −0.25 V. It is also observed that there is no significant degradation of the electrochromic properties of the porous film after 2000 continuous coloration–bleaching cycles. The remarkable electrochromic characteristics of this crystalline and nanoporous WO3 are mainly ascribed to the combination of a large surface area, facilitating increased intercalation of protons, as well as excellent continuous and directional paths for charge transfer and proton migration in the highly crystalline material.
Resumo:
We report an efficient solar-light-driven photocatalyst based on three-dimensional nanoporous tungsten trioxide (WO3) films. These films are obtained by anodizing W foils in fluoride-containing electrolytes at room temperature and under low applied voltages with an efficient growth rate of 2 μm h− 1. The maximum thickness of the films is ~ 3 μm that exceeds those of previously reported anodized WO3 films in fluoride-containing electrolytes. By investigating the photocatalytic properties of the films with thicknesses ranging from ~ 0.5 to ~ 3 μm, the optimum thickness of the nanoporous film is found to be ~ 1 μm, which demonstrates an impressive 120% improvement in the photocatalytic performance compared to that of a RF-sputtered nanotextured film with similar weights. We mainly ascribe this to large surface area and smaller bandgap.
Resumo:
• Government reports consistently recognise the importance of Primary Health Care to an efficient health system. Barriers identified in Australia’s Primary Health Care include workforce pressures, increase rate of chronic disease, and equitable access to Primary Health Care services. • General Practitioners (GPs) are the key to the successful delivery of Primary Health Care especially in rural and remote regions such as the Wheatbelt region in Western Australia (WA). • The Wheatbelt region of WA is vast: some 72,500 residents spread across 150,000km2 in 43 Local Government Authorities catchments. Majority of the Wheatbelt residents live in small towns. There is a higher reported rates of chronic disease, more at risk of chronic diseases and less utilisation of Primary Health Care services in this region. • General practice patients in the Wheatbelt are among those most in need of Primary Health Care services. • Wheatbelt GP Network (the “Network”) was established in 1998. It is a key health service delivery stakeholder in the Wheatbelt. • The Network has responded to the health needs of the community by creating a mobile Allied Health Team that works closely with GPs and is adaptive to ensure priority needs are met. • The Medicare Local model introduced by the Australian Government in 2011 aimed to improve the delivery of Primary Health Care services by improved health planning and coordinating service delivery. • Little if any recognition has been given to the outstanding work that many Divisions of General Practice have done in improving the delivery of Primary Health Care services such as the Network. • The Network has continued to support GPs and general practices and created a complementary system that integrated general practice with the work of an Allied Health Team. Its program mix is extensive. • The Network has consistently delivered on-required contract outputs and has a fifteen (15) years history of operating successfully in a large geographical area comprising in the main smaller communities that cannot support the traditional health services model. • The complexity of supporting International Medical Graduates in the region requires special attention. • The introduction of the Medicare Local in the South West of WA and their intention to take over the delivery of health services, thus effectively shutting the Network will have catastrophic consequences and cannot be supported economically. • The Network proposes to create a new model, built on its past work that increases the delivery of Primary Health Care services through its current Allied Health Team. • The proposal uses the Wheatbelt GP Super Clinic currently under construction in Northam, part of the Network and funded by the Australian Government is a key to the proposed new model. • Wheatbelt GP Super Clinic is different from existing models of GP Super Clinics around Australia which focus predominately on co-location of services. Wheatbelt GP Super Clinic utilises a hub and spoke model of service outreach to small rural towns to ensure equitable Primary Health Care coverage and continuum of care in a financially responsible and viable manner. In particular, the Wheatbelt GP Super Clinic recognises the importance of Allied Health Professionals and will involve them in a collaborative model with rural general practice. • The proposed model advocated by the Network aims to substitute the South West WA Medicare Local direct service delivery proposed for the Wheatbelt. The Network’s proposed model is to expand on the current hub and spoke model of Primary Health Care delivery to otherwise small unviable Wheatbelt towns. A flexible and adaptive skill mix of Allied Health Professionals, Nurse Practitioners and GPs ensure equitable access to service. Expanded scope of practices are utilised to reduce duplication of service and concentration of services in major towns. This involves a partnership approach. • If the proposed model not funded, the Network and the Wheatbelt region will stand to lose 16 Allied Health Professionals and defeats the purpose of Australian Government current funding for the construction of the Wheatbelt GP Super Clinic. • The Network has considered how its model can best be funded. It proposes a re-allocation of funds made available to the South West WA Medicare Local. • This submission argues that the proposal for the South West WA Medicare Local to take over the service delivery of Primary Health Care services in the Wheatbelt makes no economic sense when an existing agency (the Network) has the infrastructure in place, is experienced in working in this geographical area that has special needs and is capable to expand its programs to meet demand.
Resumo:
Carbon nanowalls (CNWs) are self-assembled, free-standing, few-layered graphenenano-structures with large surface area, and thin graphene edges. For their application to nanobiotechnology, the effects of chemisorbed species on surface wettability were investigated. The surfaces of as-grown CNWs obtained using CH4/H2 mixture were hydrophilic. After Ar atmospheric pressure plasma treatments for up to 30 s, the contact angles of water droplets on the CNWs decreased from 51° to 5°, owing to a result of oxidation only at edges and surface defects. They increased up to 147° by CF4 plasma treatment at low pressure. The wide-range control of surface wettability of CNWs was realized by post-growth plasma treatments. We also demonstrated detection of bovine serum albumin using surface-modified CNWs as electrodes.
Resumo:
Vertical graphene nanosheets (VGNS) hold great promise for high-performance supercapacitors owing to their excellent electrical transport property, large surface area and in particular, an inherent three-dimensional, open network structure. However, it remains challenging to materialise the VGNS-based supercapacitors due to their poor specific capacitance, high temperature processing, poor binding to electrode support materials, uncontrollable microstructure, and non-cost effective way of fabrication. Here we use a single-step, fast, scalable, and environmentally-benign plasma-enabled method to fabricate VGNS using cheap and spreadable natural fatty precursor butter, and demonstrate the controllability over the degree of graphitization and the density of VGNS edge planes. Our VGNS employed as binder-free supercapacitor electrodes exhibit high specific capacitance up to 230 F g−1 at a scan rate of 10 mV s−1 and >99% capacitance retention after 1,500 charge-discharge cycles at a high current density, when the optimum combination of graphitic structure and edge plane effects is utilised. The energy storage performance can be further enhanced by forming stable hybrid MnO2/VGNS nano-architectures which synergistically combine the advantages from both VGNS and MnO2. This deterministic and plasma-unique way of fabricating VGNS may open a new avenue for producing functional nanomaterials for advanced energy storage devices.
Resumo:
A simple, uniquely plasma-enabled and environment-friendly process to reduce the thickness of vertically standing graphenes to only 4–5 graphene layers and arranging them in dense, ultra-large surface area, ultra-open-edge-length, self-organized and interconnected networks is demonstrated. The approach for the ultimate thickness reduction to 1–2 graphene layers is also proposed. The vertical graphene networks are optically transparent and show tunable electric properties from semiconducting to semi-metallic and metallic at room and near-room temperature, thus recovering semi-metallic properties of a single-layer graphene.
Resumo:
This thesis explored traffic characteristics at the aggregate level for area-wide traffic monitoring of large urban area. It focused on three aspects: understanding a macroscopic network performance under real-time traffic information provision, measuring traffic performance of a signalised arterial network using available data sets, and discussing network zoning for monitoring purposes in the case of Brisbane, Australia. This work presented the use of probe vehicle data for estimating traffic state variables, and illustrated dynamic features of regional traffic performance of Brisbane. The results confirmed the viability and effectiveness of area-wide traffic monitoring.
Resumo:
Purpose To highlight the finding of occult areas of poor epithelial adhesion in the superior perilimbal cornea in a minority of patients with recalcitrant recurrent corneal erosion syndrome presenting with corneal erosion elsewhere on the corneal surface. Patient population 31 eyes of 31 consecutive patients with corneal erosion undergoing mechanical debridement of the epithelium prior to diamond burr keratectomy for recurrent corneal erosion. Methods Determine the location and incidence of poor epithelial adhesion distant from the initial erosion by use of mechanical debridement with a dry microsponge. Results During debridement, 8 of 31 eyes (25.8%) displayed a large arcuate area of occult dysfunction of adhesion in the superior perilimbal area. None of these patients showed recurrence over a mean of 18 month after diamond burr keratectomy (95% confidence interval 0-36.9%). Conclusion Mechanical debridement with a microsponge identified a significant minority of patients with poor adhesion in the superior perilimbal cornea away from the area of obvious erosion and increased the target area for diamond burr keratectomy. This two pronged approach allowed successful management of this group.
Resumo:
Genotype-environment interactions (GEI) limit genetic gain for complex traits such as tolerance to drought. Characterization of the crop environment is an important step in understanding GEI. A modelling approach is proposed here to characterize broadly (large geographic area, long-term period) and locally (field experiment) drought-related environmental stresses, which enables breeders to analyse their experimental trials with regard to the broad population of environments that they target. Water-deficit patterns experienced by wheat crops were determined for drought-prone north-eastern Australia, using the APSIM crop model to account for the interactions of crops with their environment (e.g. feedback of plant growth on water depletion). Simulations based on more than 100 years of historical climate data were conducted for representative locations, soils, and management systems, for a check cultivar, Hartog. The three main environment types identified differed in their patterns of simulated water stress around flowering and during grain-filling. Over the entire region, the terminal drought-stress pattern was most common (50% of production environments) followed by a flowering stress (24%), although the frequencies of occurrence of the three types varied greatly across regions, years, and management. This environment classification was applied to 16 trials relevant to late stages testing of a breeding programme. The incorporation of the independently-determined environment types in a statistical analysis assisted interpretation of the GEI for yield among the 18 representative genotypes by reducing the relative effect of GEI compared with genotypic variance, and helped to identify opportunities to improve breeding and germplasm-testing strategies for this region.
Resumo:
In this proof-of-concept study, an agricultural biocide (imidacloprid) was effectively loaded into the mesoporous silica nanoparticles (MSNs) with different pore sizes, morphologies and mesoporous structures for termite control. This resulted in nanoparticles with a large surface area, tunable pore diameter and small particle size, which are ideal carriers for adsorption and controlled release of imidacloprid. The effect of pore size, surface area and mesoporous structure on uptake and release of imidacloprid was systematically studied. It was found that the adsorption amount and release profile of imidacloprid were dependent on the type of mesoporous structure and surface area of particles. Specifically, MCM-48 type mesoporous silica nanoparticles with a three dimensional (3D) open network structure and high surface area displayed the highest adsorption capacity compared to other types of silica nanoparticles. Release of imidacloprid from these nanoparticles was found to be controlled over 48 hours. Finally, in vivo laboratory testing on termite control proved the efficacy of these nanoparticles as delivery carriers for biopesticides. We believe that the present study will contribute to the design of more effective controlled and targeted delivery for other biomolecules.
Resumo:
The occurrence and nature of civilian firearm- and explosion-injuries in Finland, and the nature of severe gunshot injuries of the extremities were described in seven original articles. The main data sources used were the National Hospital Discharge Register, the Cause-of-Death Register, and the Archive of Death Certificates at Statistics Finland. The present study was population based. Epidemiologic methods were used in six and clinical analyses in five papers. In these clinical studies, every original hospital record and death certificate was critically analyzed. The trend of hospitalized firearm injuries has slightly declined in Finland from the late 1980s to the early 2000s. The occurrence decreased from 5.1 per 100 000 person-years in 1990 to 2.6 in 2003. The decline was found in the unintentional firearm injuries. A high incidence of unintentional injuries by firearms was characteristic of the country, while violence and homicides by firearms represented a minor problem. The incidence of fatal non-suicidal firearm injuries has been stable, 1.8 cases per 100 000 person-years. Suicides using firearms were eight times more common during the period studied. This is contrary to corresponding reports from many other countries. However, the use of alcohol and illegal drugs or substances was detected in as many as one-third of the injuries studied. The median length of hospitalization was three days and it was significantly associated (p<0.001) with the type of injury. The mean length of hospital stay has decreased from the 1980s to the early 2000s. In this study, there was a special interest in gunshot injuries of the extremities. From a clinical point of view, the nature of severe extremital gunshot wounds, as well as the primary operative approach in their management, varied. The patients with severe injuries of this kind were managed at university and central hospital emergency departments, by general surgeons in smaller hospitals and by cardiothoracic or vascular surgeons in larger hospitals. Injuries were rarities and as such challenges for surgeons on call. Some noteworthy aspects of the management were noticed and these should be focused on in the future. On the other hand, the small population density and the relatively large geographic area of Finland do not favor high volume, centralized trauma management systems. However, experimental war surgery has been increasingly taught in the country from the 1990s, and excellent results could be expected during the present decade. Epidemiologically, explosion injuries can be considered a minor problem in Finland at present, but their significance should not be underestimated. Fatal explosion injuries showed up sporadically. An increase occurred from 2002 to 2004 for no obvius reason. However, in view of the historical facts, a possibility for another rare major explosion involving several people might become likely within the next decade. The national control system of firearms is mainly based on the new legislations from 1998 and 2002. However, as shown in this study, there is no reason to assume that the national hospitalization policies, or the political climate, or the legislation might have changed over the study period and influenced the declining development, at least not directly. Indeed, the reason for the decline to appear in the incidence of unintentional injuries only remains unclear. It may derive from many practical steps, e.g. locked firearm cases, or from the stability of the community itself. For effective reduction of firearm-related injuries, preventive measures, such as education and counseling, should be targeted at recreational firearm users. To sum up, this study showed that the often reported increasing trend in firearm as well as explosion-related injuries has not manifested in Finland. Consequently, it can be recognized that, overall, the Finnish legislation together with the various strategies have succeeded in preventing firearm- and explosion-related injuries in the country.
Resumo:
Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ∼4 nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a mixed paramagnetic and ferromagnetic state, originating from the core and surface, respectively. The 3D nanodendrite structure is suitable for surface modification and high amounts of drug loading if the transition temperature was enhanced to room temperature properly.
Resumo:
MnO2 is currently under extensive investigations for its capacitance properties. MnO2 crystallizes into several crystallographic structures, namely, α, β, γ, δ, and λ structures. Because these structures differ in the way MnO6 octahedra are interlinked, they possess tunnels or interlayers with gaps of different magnitudes. Because capacitance properties are due to tercalation/deintercalation of protons or cations in MnO2, only some crystallographic structures, which possess sufficient gaps to accommodate these ions, are expected to be useful for capacitance studies. In order to examine the dependence of capacitance on crystal structure, the present study involves preparation of these various crystal phases of MnO2 in nanodimensions and to evaluate their capacitance properties. Results of α-MnO2 prepared by a microemulsion route (α-MnO2(m)) are also used for comparison. Spherical particles of about 50 nm, nanorods of 30−50 nm in diameter, or interlocked fibers of 10−20 nm in diameters are formed, which depend on the crystal structure and the method of preparation. The specific capacitance (SC) measured for MnO2 is found to depend strongly on the crystallographic structure, and it decreases in the following order: α(m) > α δ > γ > λ > β. A SC value of 297 F g-1 is obtained for α-MnO2(m), whereas it is 9 F g-1 for β-MnO2. A wide (4.6 Å) tunnel size and large surface area of α-MnO2(m) are ascribed as favorable factors for its high SC. A large interlayer separation (7 Å) also facilitates insertion of cations in δ-MnO2 resulting in a SC close to 236 F g-1. A narrow tunnel size (1.89 Å) does not allow intercalation of cations into β-MnO2. As a result, it provides a very small SC.
Resumo:
The discovery of graphene has aroused great interest in the properties and phenomena exhibited by two-dimensional inorganic materials, especially when they comprise only a single, two or a few layers. Graphene-like MoS2 and WS2 have been prepared by chemical methods, and the materials have been characterized by electron microscopy, atomic force microscopy (AFM) and other methods. Boron nitride analogues of graphene have been obtained by a simple chemical procedure starting with boric acid and urea and have been characterized by various techniques that include surface area measurements. A new layered material with the composition BCN possessing a few layers and a large surface area discovered recently exhibits a large uptake of CO2.
Resumo:
Porous, large surface area, metastable zirconias, are of importance to catalytic, electrochemical, biological, and thermal insulation applications. Combustion synthesis is a very commonly used method for producing such zirconias. However, its rapid nature makes control difficult. A simple modification has been made to traditional solution combustion synthesis to address this problem. It involves the addition of starch to yield a starting mixture with a ``dough-like'' consistency. Just 5 wt% starch is seen to significantly alter the combustion characteristics of the ``dough.'' In particular, it helps to achieve better control over reaction zone temperature that is significantly lower than the one calculated by the adiabatic approximation typically used in self-propagating high-temperature synthesis. The effect of such control is demonstrated by the ability to tune dough composition to yield zirconias with different phase compositions from the relatively elusive ``amorphous'' to monoclinic (> 30 nm grain size) and tetragonal pure zirconia (< 30 nm grain size). The nature of this amorphous phase has been investigated using infrared spectroscopy. Starch content also helps tailor porosity in the final product. Zirconias with an average pore size of about 50 mu m and specific surface area as large as 110 m2/g have been obtained.