Structure and capacitive properties of porous nanocrystalline VN produced by NH3 reduction of V2O5

Vanadium nitride (VN) is currently one of the most promising materials for electrodes of supercapacitors. The structure and electrochemical properties of VN synthesized by temperature-programmed NH₃ reduction of V₂O₅ are analyzed in this paper. Vanadium nitride produced via this route has distinctive structural characteristics. VN mimics the shape of the initial V₂O₅ precursor indicating a pronounced direct attachment of nitride grains. The particles have domains of grains with a preferential orientation (texture). The large volume of pores in VN is represented by the range of 15−110 nm. VN demonstrates capacitive properties in three different types of aqueous electrolytes, 1 M KOH, 1 M H₂SO₄, and 3 M NaCl. The material has an acceptable rate capability in all electrolytes, showing about 80% of its maximal capacitance at a current load of 1 A/g in galvanostatic charging/discharging experiments. The capacitance of 186 F/g is observed in 1 M KOH electrolyte at 1 A/g. The previously reported negative effect of material loading on the capacitance is significantly suppressed. The observed electrochemical characteristics related to the application of this material in supercapacitors can be correlated with the crystalline structure of the nitride and the composition of its surface layer.

Powdered activated carbon for fouling reduction of membrane in a pilot-scale recirculation aquaculture system

Recirculating aquaculture systems (RAS) are essential for the reduction in fresh water usage as well as the discharge of nutrients along with aquaculture effluents. A RAS consisting of an anoxic reactor, a membrane bioreactor (MBR) and a UV-disinfection unit was used to process 10,000 L/d of aquaculture effluent providing high-quality treated water for recirculation to a Barramundi fish culture. The system maintained low levels of nitrate (<20 mg/L), nitrite (<3 mg/L) and ammonia (<0.6 mg/L) in the fish tank. Permeate from the membrane that was recirculated to the fish tank contained <21 mg/L of nitrate, <2 mg/L of nitrite and 0 mg/L of ammonia. However, the rate of fouling of the membrane in the MBR was around 1.47 kPa/d, and the membrane in the MBR required cleaning due to fouling after 16 days. Cleaning of the membrane was initiated when the TMP reached around 25 to 30 kPa. In order to reduce the rate of fouling, 500 mg of powdered activated carbon (PAC) per litre of MBR volume was introduced, which decreased the rate of fouling to 0.90 kPa/d. Cleaning of membrane was needed only after 31 days of operation while maintaining the treated effluent quality. Thus the frequency of cleaning could be halved due to the introduction of PAC into the MBR.

Dimensionality reduction of protein mass spectrometry data using random projection

Protein mass spectrometry (MS) pattern recognition has recently emerged as a new method for cancer diagnosis. Unfortunately, classification performance may degrade owing to the enormously high dimensionality of the data. This paper investigates the use of Random Projection in protein MS data dimensionality reduction. The effectiveness of Random Projection (RP) is analyzed and compared against Principal Component Analysis (PCA) by using three classification algorithms, namely Support Vector Machine, Feed-forward Neural Networks and K-Nearest Neighbour. Three real-world cancer data sets are employed to evaluate the performances of RP and PCA. Through the investigations, RP method demonstrated better or at least comparable classification performance as PCA if the dimensionality of the projection matrix is sufficiently large. This paper also explores the use of RP as a pre-processing step prior to PCA. The results show that without sacrificing classification accuracy, performing RP prior to PCA significantly improves the computational time.

Reduction of the photocatalytic activity of ZnO nanoparticles for UV protection applications

The detrimental effects of UV radiation are having a significant impact on our life and environment. The development of effective UV shielding agents is therefore of great importance to our society. ZnO nanoparticles are considered to be one of the most effective UV blocking agents. However, the development of ZnO-based UV shielding products is currently hindered due to the adverse effects of the inherent photocatalytic activity exhibited by ZnO. This paper reports our recent study on the possibility of reducing the photoactivity of ZnO nanoparticles via surface modification and impurity doping. It was found that the photoactivity was drastically reduced by SiO2-coatings that were applied to ZnO quantum dots using the Stöber method and a microemulsion technique. The effect of transition metal doping on the photoactivity was also studied using mechanochemical processing and a co-precipitation method. Cobalt doping reduced the photoactivity, while manganese doping led to mixed results, possibly due to the difference in the location of dopant ions derived from the difference in the synthesis methods.

A preliminary study on the volume reduction of pre-treatment sludge in seawater desalination by forward osmosis

Forward Osmosis (FO) can be applied to recover water from the pre-treatment sludge of seawater reverse osmosis process. This study investigated the effect of the concentration of two draw solutions (MgCl₂ and NaCl) in the reduction of Fe(OH)₃ sludge volume and the effect of cross flow velocity on flux through FO membrane. Higher the concentration of NaCl and MgCl₂ higher the water flux observed. However, the percentage increase was not significant due to the occurrence of internal concentration polarisation. MgCl₂ draws marginally increased water flux than NaCl, when the conditions of feed and draw solutions were similar. Increase in cross flow velocity (from 0.25 to 1.0 m/s) marginally changed the flux with both draw solutions as higher cross flow velocities were unproductive to beat the external CP effect along the membrane surface. However, at 1 m/s, highest fluxes were obtained for both draw solutions.

Reduction of adolescent alcohol use through family-school intervention: a randomized trial

Purpose
Two-year longitudinal follow-up data evaluated the behavioral impact of Resilient Families, a universal intervention that aimed to prevent early initiation and frequent and heavy adolescent alcohol use in secondary schools in Melbourne, Australia.

Methods
Of 24 secondary schools (62% of those approached), 12 were randomly assigned to intervention and 12 as controls. Intervention students received a social relationship curriculum; their parents received parent education handbooks and invitations to parent education events outlining strategies to encourage healthy adolescent development and reduce adolescent alcohol misuse. At Wave 1 (2004), students were in Year 7 secondary school (mean age, 12.3 years). Data were imputed for students completing at least two of three annual surveys (N = 2,354). Wave 3 (2006; mean, 14.5 years) main outcome measures for alcohol use were “any,” “frequent” (at least monthly), and “heavy” (five or more drinks in a session at least once in the prior fortnight). Multivariate logistic regression assessed intervention exposure effects, adjusting for school classroom clustering and baseline measures.

Results
Relative to controls, intervention students showed significant reductions in any lifetime use (adjusted odds ratio [AOR], .78; 95% confidence interval [CI], .62–.97), and reduced progression to frequent (AOR, .69; CI, .56–.86) and heavy use (AOR, .75; CI, .60–.94).

Conclusions
Randomized assignment to Resilient Families was associated with a significant reduction in adolescent alcohol use among families volunteering for the evaluation. Family–school-based interventions appear promising as a strategy to contribute to population reductions in currently high rates of adolescent alcohol misuse.

The contribution of residential solar energy systems to the reduction of greenhouse gas emissions in the borough of Queenscliffe

The Borough of Queenscliffe has identified the importance of reducing its greenhouse gas emissions and aims to become a carbon zero municipality by 2020. For a house, suburb or town to become carbon neutral ideally it produces an equivalent amount of energy from renewable resources to that which it consumes. By increasing the number of solar systems, both photovoltaic (PV) and hot water, in the residential sector, greenhouse gas emissions will be reduced. The number of solar systems located in the Borough of Queenscliffe has been estimated and a database of these systems has been created, including the size and panel orientation. The energy generated by each solar system, in addition to the reductions in greenhouse gas emissions, has been calculated for an average year.