Thin film deposition and characterization of pure and iron-doped electron-beam evaporated tungsten oxide for gas sensors

Pure Tungsten Oxide (WO3) and Iron-doped (10 at%) Tungsten Oxide (WO3:Fe) nanostructured thin films were prepared using a dual crucible Electron Beam Evaporation techniques. The films were deposited at room temperature in high vacuum condition on glass substrate and post-heat treated at 300 oC for 1 hour. From the study of X-ray diffraction and Raman the characteristics of the as-deposited WO3 and WO3:Fe films indicated non-crystalline nature. The surface roughness of all the films showed in the order of 2.5 nm as observed using Atomic Force Microscopy (AFM). X-Ray Photoelectron Spectroscopy (XPS) analysis revealed tungsten oxide films with stoichiometry close to WO3. The addition of Fe to WO3 produced a smaller particle size and lower porosity as observed using Transmission Electron Microscopy (TEM). A slight difference in optical band gap energies of 3.22 eV and 3.12 eV were found between the as-deposited WO3 and WO3:Fe films, respectively. However, the difference in the band gap energies of the annealed films were significantly higher having values of 3.12 eV and 2.61 eV for the WO3 and WO3:Fe films, respectively. The heat treated samples were investigated for gas sensing applications using noise spectroscopy and doping of Fe to WO3 reduced the sensitivity to certain gasses. Detailed study of the WO3 and WO3:Fe films gas sensing properties is the subject of another paper.

Computer simulation and modeling in railway applications

An electrified railway system includes complex interconnections and interactions of several subsystems. Computer simulation is the only viable means for system evaluation and analysis. This paper discusses the difficulties and requirements of effective simulation models for this specialized industrial application; and the development of a general-purpose multi-train simulator.

A free weekly iron-folic acid supplementation and regular deworming program is associated with improved hemoglobin and iron status indicators in Vietnamese women

Background Anemia due to iron deficiency is recognized as one of the major nutritional deficiencies in women and children in developing countries. Daily iron supplementation for pregnant women is recommended in many countries although there are few reports of these programs working efficiently or effectively. Weekly iron-folic acid supplementation (WIFS) and regular deworming treatment is recommended for non-pregnant women living in areas with high rates of anemia. Following a baseline survey to assess the prevalence of anemia, iron deficiency and soil transmitted helminth infections, we implemented a program to make WIFS and regular deworming treatment freely and universally available for all women of reproductive age in two districts of a province in northern Vietnam over a 12 month period. The impact of the program at the population level was assessed in terms of: i) change in mean hemoglobin and iron status indicators, and ii) change in the prevalence of anemia, iron deficiency and hookworm infections. Method Distribution of WIFS and deworming were integrated with routine health services and made available to 52,000 women. Demographic data and blood and stool samples were collected in baseline, and three and 12-month post-implementation surveys using a population-based, stratified multi-stage cluster sampling design. Results The mean Hb increased by 9.6 g/L (95% CI, 5.7, 13.5, p < 0.001) during the study period. Anemia (Hb<120 g/L) was present in 131/349 (37.5%, 95% CI 31.3, 44.8) subjects at baseline, and in 70/363 (19.3%, 95% CI 14.0, 24.6) after twelve months. Iron deficiency reduced from 75/329 (22.8%, 95% CI 16.9, 28.6) to 33/353 (9.3%, 95% CI 5.7, 13.0) by the 12-mnth survey, and hookworm infection from 279/366 (76.2%,, 95% CI 68.6, 83.8) to 66/287 (23.0%, 95% CI 17.5, 28.5) over the same period. Conclusion A free, universal WIFS program with regular deworming was associated with reduced prevalence and severity of anemia, iron deficiency and ho

Sensing properties of e-beam evaporated nanostructured pure and iron-doped tungsten oxide thin films

Gas sensing properties of nanostructured pure and iron-doped WO3 thin films are discussed. Electron beam evaporation technique has been used to obtain nanostructured thin films of WO3 and WO3:Fe with small grain size and porosity. Atomic force microscopy has been employed to study the microstructure. High sensitivity of both films towards NO2 is observed. Doping of the tungsten oxide film with Fe decreased the material resistance by a factor of about 30 when exposed to 5 ppm NO2. The high sensitivity is attributed to an improved microstructure of the films obtained through e-beam evaporation technique, and subsequent annealing at 300oC for 1 hour.

A Process and Outcome Evaluation of the Under the Limit (UTL) Therapeutic Drink Driving Program for Recidivist and High Range Offenders

Drink driving is a major public health issue and this report examines the experiences of convicted offenders who participated in an established drink driving rehabilitation program Under the Limit (UTL). Course completers were surveyed at least three months after they had finished the 11-week UTL course. The aim of this study was to examine whether the UTL program reduced the level of alcohol consumption either directly as a result of participation in the UTL drink driving program or through increased use of community alcohol program by participants. The research involved a self-report outcome evaluation to determine whether the self-reported levels of alcohol use after the course had changed from the initial alcohol use reported by offenders. The findings are based on the responses of 30 drink-driving offenders who had completed the UTL program (response rate: 20%). While a process evaluation was proposed in the initial application, the low response rate meant that this follow up research was not feasible. The response rate was low for two reasons, it was difficult to: recruit participants who consented to follow up, and subsequently locate and survey those who had consented to involvement.

Theoretical study of two states reactivity of methane activation on iron atom and iron dimer

Density functional theory (DFT) calculations have been carried out to explore the catalytic activation of C–H bonds in methane by the iron atom, Fe, and the iron dimer, Fe2. For methane activation on an Fe atom, the calculations suggest that the activation of the first C–H bond is mediated via the triplet excited-state potential energy surface (PES), with initial excitation of Fe to the triplet state being necessary for the reaction to be energetically feasible. Compared with the breaking of the first C–H bond, the cleavage of the second C–H bond is predicted to involve a significantly higher barrier, which could explain experimental observations of the HFeCH3 complex rather than CH2FeH2 in the activation of methane by an Fe atom. For methane activation on an iron dimer, the cleavage of the first C–H bond is quite facile with a barrier only 11.2, 15.8 and 8.4 kcal/mol on the septet state energy surface at the B3LYP/6-311+G(2df,2dp), BPW91/6-311+G(2df,2dp) and M06/B3LYP level, respectively. Cleavage of the second C–H bond from HFe2CH3 involves a barrier calculated respectively as 18.0, 10.7 and 12.4 kcal/mol at the three levels. The results suggest that the elimination of hydrogen from the dihydrogen complex is a rate-determining step. Overall, our results indicate that the iron dimer Fe2 has a stronger catalytic effect on the activation of methane than the iron atom.

The infectivity and host range of Orgyia anartoides nucleopolyhedrovirus

The painted apple moth (PAM), Teia anartoides (Walker) (Lepidoptera: Lymantriidae) made a recent incursion into New Zealand. A nucleopolyhedrovirus (NPV), Orgyia anartoides NPV (OranNPV), originally isolated from PAM in Australia, was tested for its pathogenicity to PAM and a range of non-target insect species found in New Zealand, to evaluate its suitability as a microbial control for this insect invader. Dosage-mortality tests showed that OranNPV was highly pathogenic to PAM larvae; mean LT50 values for third instars ranged from 17.9 to 8.1 days for doses from 102 to 105 polyhedral inclusion bodies/larva, respectively. The cause of death in infected insects was confirmed as OranNPV. Molecular analysis established that OranNPV can be identified by PCR and restriction digestion, and this process complemented microscopic examination of infected larvae. No lymantriid species occur in New Zealand; however, the virus had no significant effects on species from five other lepidopteran families (Noctuidae, Tortricidae, Geometridae, Nymphalidae and Plutellidae) or on adult honeybees. Thus, all indications from this initial investigation are that OranNPV would be an important tool in the control of PAM in a future incursion of this species into New Zealand.

Driver behaviour and decision making at railway level crossings : An exploratory on-road case study

Crashes at rail level crossings represent a significant problem, both in Australia and worldwide. Advances in driving assessment methods, such as the provision of on-road instrumented test vehicles, now provide researchers with the opportunity to further understand driver behaviour at rail level crossings in ways not previously possible. This paper gives an overview of a recent on-road pilot study of driver behaviour at rail level crossings in which 25 participants drove a pre-determined route, incorporating 4 rail level crossings, using MUARC's instrumented On-Road Test Vehicle (ORTeV). Drivers provided verbal commentary whilst driving the route, and a range of other data were collected, including eye fixations, forward, cockpit and driver video, and vehicle data (speed, braking, steering wheel angle, lane tracking etc). Participants also completed a post trial cognitive task analysis interview. Extracts from the wider analyses are used to examine in depth driver behaviour at one of the rail level crossings encountered during the study. The analysis presented, along with the overall analysis undertaken, gives insight into the driver and wider systems factors that shape behaviour at rail level crossings, and highlights the utility of using a multi-method, instrumented vehicle approach for gathering data regarding driver behaviour in different contexts.

Particle number and mass emission factors from combustion of wood samples collected from Queensland forest

Knowledge of particle emission characteristics associated with forest fires and in general, biomass burning, is becoming increasingly important due to the impact of these emissions on human health. Of particular importance is developing a better understanding of the size distribution of particles generated from forest combustion under different environmental conditions, as well as provision of emission factors for different particle size ranges. This study was aimed at quantifying particle emission factors from four types of wood found in South East Queensland forests: Spotted Gum (Corymbia citriodora), Red Gum (Eucalypt tereticornis), Blood Gum (Eucalypt intermedia), and Iron bark (Eucalypt decorticans); under controlled laboratory conditions. The experimental set up included a modified commercial stove connected to a dilution system designed for the conditions of the study. Measurements of particle number size distribution and concentration resulting from the burning of woods with a relatively homogenous moisture content (in the range of 15 to 26 %) and for different rates of burning were performed using a TSI Scanning Mobility Particle Sizer (SMPS) in the size range from 10 to 600 nm and a TSI Dust Trak for PM2.5. The results of the study in terms of the relationship between particle number size distribution and different condition of burning for different species show that particle number emission factors and PM2.5 mass emission factors depend on the type of wood and the burning rate; fast burning or slow burning. The average particle number emission factors for fast burning conditions are in the range of 3.3 x 1015 to 5.7 x 1015 particles/kg, and for PM2.5 are in the range of 139 to 217 mg/kg.

Characteristics and predictors of high-range speeding offenders

This paper examines an aspect of the data taken from a larger study evaluating the effect of speeding penalty changes on speeding recidivism in Queensland. Traffic offence data from May 1996 to August 2007 were provided to the research team for two cohorts of offenders: individuals who committed a speeding offence in May 2001; and individuals who committed a speeding offence in May 2003. Data included details of the offenders’ index offence, previous and subsequent traffic offences (speeding and other) and their demographic characteristics. Using this data the aim of this component of the research was to use demographic data and the previous traffic offences of these individuals to explore the characteristics and predictors of high-range speeding offenders. High-range offenders were identified as those individuals who committed two or more speeding offences with a recorded speed of 30 km/hr or more above the speed limit. For the purposes of comparison, low-range offenders (committed one speeding offence in the time-frame and that offence was less than 15 km/hr over the speed limit) and mid-range offenders (all other offenders) were identified. Using Chi-square and logistic regression analyses, characteristics and predictors of high-range speeding offenders were identified. The implications and limitations of this study are also discussed.

Traffic and climate change impacts on water quality : measuring build-up and wash-off of heavy metals and petroleum hydrocarbons

Understanding the impacts of traffic and climate change on water quality helps decision makers to develop better policy and plans for dealing with unsustainable urban and transport development. This chapter presents detailed methodologies developed for sample collection and testing for heavy metals and total petroleum hydrocarbons, as part of a research study to investigate the impacts of climate change and changes to urban traffic characteristics on pollutant build-up and wash-off from urban road surfaces. Cadmium, chromium, nickel, copper, lead, iron, aluminium, manganese and zinc were the target heavy metals, and selected gasoline and diesel range organics were the target total petroleum hydrocarbons for this study. The study sites were selected to encompass the urban traffic characteristics of the Gold Coast region, Australia. An improved sample collection method referred to as ‘the wet and dry vacuum system’ for the pollutant build-up, and an effective wash-off plan to incorporate predicted changes to rainfall characteristics due to climate change, were implemented. The novel approach to sample collection for pollutant build-up helped to maintain the integrity of collection efficiency. The wash-off plan helped to incorporate the predicted impacts of climate change in the Gold Coast region. The robust experimental methods developed will help in field sample collection and chemical testing of different stormwater pollutants in build-up and wash-off.