Probabilistic Water Demand Forecasting Using Projected Climatic Data for Blue Mountains Water Supply System in Australia

Long term water demand forecasting is needed for the efficient planning and management of water supply systems. A Monte Carlo simulation approach is adopted in this paper to quantify the uncertainties in long term water demand prediction due to the stochastic nature of predictor variables and their correlation structures. Three future climatic scenarios (A1B, A2 and B1) and four different levels of water restrictions are considered in the demand forecasting for single and multiple dwelling residential sectors in the Blue Mountains region, Australia. It is found that future water demand in 2040 would rise by 2 to 33 % (median rise by 11 %) and 72 to 94 % (median rise by 84 %) for the single and multiple dwelling residential sectors, respectively under different climatic and water restriction scenarios in comparison to water demand in 2010 (base year). The uncertainty band for single dwelling residential sector is found to be 0.3 to 0.4 GL/year, which represent 11 to 13 % variation around the median forecasted demand. It is found that the increase in future water demand is not notably affected by the projected climatic conditions but by the increase in the dwelling numbers in future i.e. the increase in total population. The modelling approach presented in this paper can provide realistic scenarios of forecasted water demands which would assist water authorities in devising appropriate management strategies to enhance the resilience of the water supply systems. The developed method can be adapted to other water supply systems in Australia and other countries.     

Castor Epoxy Fatty Acid Alkyl Ester Estolides as Bioplasticizers for Poly(Vinyl Chloride)

Epoxy fatty acid alkyl ester estolides were synthesized from castor oil to be used as biobased plasticizers for poly(vinyl chloride) (PVC) as a safer replacement for phthalate plasticizers. Initially, castor oil was transesterified with methanol or n-butanol to quantitatively yield castor fatty acid alkyl esters. Acetylation of hydroxyl function with acetic anhydride led to the formation of estolide. The unsaturation was epoxidized, resulting in a bifunctional epoxy fatty acid alkyl ester estolide. The bioplasticizers were compounded with PVC and were evaluated for their functionality and compared with commercial phthalate plasticizer diisononyl phthalate (DINP) and nonphthalate 1,2-cyclohexanoic acid diisononyl ester (DINCH). The bioplasticizers showed excellent gelation, efficiency, and compatibility, as well as plastisol viscosity and thermal properties, comparable to or better than the plastisols prepared with commercial controls DINP and DINCH. The volatility of the methyl ester was inferior to the butyl ester. Both compounds showed low water resistance properties. Further evaluation of the butyl ester under tropical conditions of high temperature and humidity confirmed limited compatibility. This indicates that the castor epoxy fatty acid ester estolides would be better suited for applications that do not come in contact with water for prolonged periods, such as flooring, artificial leather, wiring, or wall coverings.     

Discontinuity waves of orderr≧1 in an inhomogeneous anisotropic linear elastic solid

Summary In the present paper we study the propagation of discontinuity waves of orderr (r=fixed integer 1) travelling through an inhomogeneous anisotropic linear elastic solid. By means of the theory of singular surfaces and the ray-theory we determine the evolution law of ther-th discontinuity vector along the rays associated with the wave front. We find that, even if the solid is linear and contrary to the homogeneous case, the behaviour of the discontinuities depends on the orderr of the wave through the normal speed of propagation of the wave front.     

Minimisation of excess sludge production in a WWTP by coupling thermal hydrolysis and rapid anaerobic digestion.

In many cases, reducing sludge production could be the solution for wastewater treatment plants (WWTP) that here difficulty evacuating the residuals of wastewater treatment. The aim of this study was to test the possibility of minimising the excess sludge production by coupling a thermal hydrolysis stage and an anaerobic digestion with a very short HRT. The tests were carried out on a 2,500 p.e. pilot plant installed on a recycling loop between the clarifier and the actived sludge basin. The line equipped with the full scale pilot plant produced 38% TSS less than the control line during a 10 week period. Moreover, the rapid anaerobic digestion removed, on average, more than 50% of the total COD load with a hydraulic retention time (HRT) of 3 days. Lastly, the dryness of the remaining excess sludge, sanitised by the thermal hydrolysis, was more than 35% with an industrial centrifuge. This combination of thermal hydrolysis and rapid anaerobic digestion equally permits a significant gain of compactness compared to traditional anaerobic digesters.     

Crystallization kinetics of organogels prepared by rice bran wax and vegetable oils

Rice bran wax (RBX) obtained during rice bran oil purification can form organogels in edible oils. The kinetics of crystallization and the viscous properties of RBX organogels were studied using differential scanning calorimetry (DSC), viscosity changes with varying temperature, hardness measurements by penetrometry, and synchrotron radiation X-ray diffraction (SR-XRD). The organogels were prepared by RBX in concentrations of 1%, 3%, 6%, and 10% on a weight basis in salad oil, olive oil, and camellia oil. The liquid oil type had no significant effect on the melting and crystallization temperatures of the RBX. However, the viscosity and the texture of the organogels differed with liquid oil type, temperature, and RBX concentration. Changes in the viscosity of the RBX organogels were monitored during cooling from 80°C to 20°C. Drastic viscosity changes occurred in accordance with the onset of crystallization in DSC thermographs obtained at a rate of 5°C/min. RBX in the olive oil and camellia oil mixtures had higher viscosity than RBX in the salad oil mixture, which correlates with the hardness obtained in texture measurements at 20°C. SR-XRD was used to clarify the crystal structures of the building blocks of the RBX organogels in salad oil. It was found that the RBX formed crystals with a long spacing of 7.3 ± 1 nm and short spacings of 0.41 ± 1 nm and 0.37 ± 1 nm. The intensity of the long-spacing pattern was remarkably weaker than that of the short-spacing patterns, which demonstrated strong anisotropy in the crystal growth of RBX crystal particles.     

Ammonia removal from effluent streams of wet oxidation under high pressure

The formation of ammonia is inevitable during industrial-scale wet oxidation of wastewater if nitrogen-containing compounds are present. This undesired side-reaction requires additional measures for disposal. Common routes are either the use of noble metal-containing catalysts in the first oxidation step or end-of-pipe treatment. Problems rise for example from the insufficient stability of solid catalysts against hydrothermal impact. As most of the wet oxidation processes run at elevated pressure and temperature, running the heterogeneously catalysed oxidation of ammonia in the gas phase in a downstream reactor could protect the catalysts mainly from leaching and offers an economic alternative by avoiding loss of unused oxygen after depressurisation. This work reports on the oxidation of ammonia with air in steam atmosphere using Cu,Cr-containing supported and bulk catalysts at 235–305 °C and 30–60 bar. A copper chromite catalyst gave best performance (86% conversion at 305 °C, 45 bar, contact time 1 s). The spinel-type phase CuCr₂O₄ seems to be the active phase and shows superior stability. The results indicate that phase behaviour of water strongly influences activity and lifetime of catalysts. Characterisation of the solids (BET, XRD, XPS, ICP) proved that deactivation is mainly caused by leaching of Cr(VI) species from catalysts when the reaction runs near to dew point of water and by loss of BET surface area of supported catalysts due to hydrothermal impact.A member of the EU-funded Coordination Action of Nanostructured Catalytic Oxide Research and Development in Europe (CONCORDE).     

TIDS: threshold and identity-based security scheme for wireless ad hoc networks

As various applications of wireless ad hoc network have been proposed, security has received increasing attentions as one of the critical research challenges. In this paper, we consider the security issues at network layer, wherein routing and packet forwarding are the main operations. We propose a novel efficient security scheme in order to provide various security characteristics, such as authentication, confidentiality, integrity and non-repudiation for wireless ad hoc networks. In our scheme, we deploy the recently developed concepts of identity-based signcryption and threshold secret sharing. We describe our proposed security solution in context of dynamic source routing (DSR) protocol. Without any assumption of pre-fixed trust relationship between nodes, the ad hoc network works in a self-organizing way to provide key generation and key management services using threshold secret sharing algorithm, which effectively solves the problem of single point of failure in the traditional public-key infrastructure (PKI) supported system. The identity-based signcryption mechanism is applied here not only to provide end-to-end authenticity and confidentiality in a single step, but also to save network bandwidth and computational power of wireless nodes. Moreover, one-way hash chain is used to protect hop-by-hop transmission.     

Use of hydrogen peroxide in scrubbing towers for odor removal in wastewater treatment plants.

The aim of this work was to replace sodium hypochlorite (NaCIO) with hydrogen peroxide (H202) in chemical scrubbing towers, in order to avoid the formation of chlorinated species, harmful for human health. Some previous studies have already shown the ability of H2O2 to treat the hydrogen sulfide (H2S) pollution. However, an important decomposition of the oxidant was observed in the scrubbing solution (carbonates, transition metal and high pH are responsible for this decomposition) leading to high reactant consumption. Consequently, this study first focused on research into a compound able to reduce the hydrogen peroxide degradation. Experiments were conducted on a pilot unit (3,000 m3 h(-1)) in a wastewater treatment plant. The sodium silicate (Na2SiO3) proved to be a good scrubbing solution stabilizer. A very good removal of hydrogen sulfide (up to 98%) was also obtained. Finally, the study resulted in the determination of the best operating conditions to achieve both an efficient and economical process.     

A flat-aluminum based voltage-programmable link forfield-programmable devices

A new metal-insulator-metal (MIM) structure has been developed for use in field-programmable gate arrays (FPGA's) as a voltage-programmable link (VPL). The present capacitor structure relies on aluminum metallization; hence, it should be amenable to immediate application. The addition of minute amounts of titanium or molybdenum has been found to suppress hillock formation. The insulator, prepared by means of plasma-enhanced chemical vapor deposition (PECVD), comprises a sandwich of a nearly stoichiometric silicon dioxide interposed between two like layers of silicon-rich silicon nitride. This MIM structure has displayed characteristics desirable for use in the emerging FPGA technology including high density, very low on-resistance, reduced capacitance, low programming voltage, and the potential for further scaling to the sub-micron regime     

Enantioselective high-performance liquid chromatography assay of (+)R- and (-)S-alpha-lipoic acid in human plasma

The Epstein-Barr virus (EBV) genome was detected by polymerase chain reaction (PCR) in mononuclear cells from bone marrows with diverse types of hematopoietic malignancies. Viral repeated sequences (BamHI-W region) were detected in 42 of 82 (51%) hematopoietic malignancies, including polycythemia vera, but not in nonneoplastic cases. EBV-positive cases were found to consist of various histological types. We did not detect any EBV PCR product in the peripheral blood. The EBV BamHI-Y, -H region, encoding EBV nuclear antigen 2 DNA, which is a single-copy gene in the viral genome, was detected in only 13 of 42 BamHI-W-positive cases, suggesting that the copy number of the EBV genome differed in each case. In all cases, the PCR band was verified by Southern blot hybridization using specific EBV probes. Whether the infected virus is an etiologic agent of the malignancy or merely a latent infection cannot be determined by the PCR assay performed under these conditions. These results, however, suggest that a novel form of EBV latent infection is present in the bone marrow of patients with hematopoietic malignancies.