Security through diversity: moving from rhetoric to practice

In response to a range of contemporary urban water challenges, there is an increasingly urgent need to change the way water is used in our cities. In Australia, the 'Security through Diversity' policy has been introduced in a number of cities to help facilitate a shift towards sustainable urban water management. This qualitative case study research investigated the interpretation and implementation of this radically different urban water policy approach across the case study cities of Perth and Melbourne. To focus the research and allow for more reliable comparative analysis across the cities, the introduction of desalination and permanent water saving rules as new initiatives in these cities were of particular interest. The research results are drawn from a synthesis of over 65 semi-structured interviews with senior urban water practitioners in the case study cities, and a content analysis of key policy and guidance documents, as well as organizational literature where available. The key finding of this research was that because of an entrenched technological paradigm, and the difficulty in breaking this pattern of lock-in, practitioners are currently interpreting and implementing Security through Diversity in a way that does not fully realise the potential of this strategy. More specifically the interview results revealed that the urban water practitioner community believed that the introduction of seawater desalination would discharge their city's responsibility for achieving Security through Diversity and that demand management initiatives, while nice, are not essential to this policy position. Interestingly, despite context evidence to the contrary, the practitioners believed supply and demand planning to be an integrated practice within their city. The paper concludes by offering some recommendations to facilitate a more comprehensive implementation of Security through Diversity and outlines areas for possible future research.     

Spatial and seasonal variations and ecotoxicological significance of sediment trace metal concentrations in Kebir-Rhumel basin (Northeast of Algeria)

This study sought to assess sediment contamination by trace metals (cadmium, chromium, cobalt, copper, manganese, nickel, lead and zinc), to localize contaminated sites and to identify environmental risk for aquatic organisms in Wadis of Kebir Rhumel basin in the Northeast of Algeria. Water and surficial sediments (0-5 cm) were sampled in winter, spring, summer and autumn from 37 sites along permanent Wadis of the Kebir Rhumel basin. Sediment trace metal contents were measured by Flame Atomic Absorption Spectroscopy. Trace metals median concentrations in sediments followed a decreasing order: Mn > Zn > Pb > Cr > Cu > Ni > Co > Cd. Extreme values (dry weights) of the trace metals are as follows: 0.6-3.4 microg/g for Cd, 10-216 microg/g for Cr, 9-446 microg/g for Cu, 3-20 microg/g for Co, 105-576 microg/g for Mn, 10-46 microg/g for Ni, 11-167 microg/g for Pb, and 38-641 microg/g for Zn. According to world natural concentrations, all sediments collected were considered as contaminated by one or more elements. Comparing measured concentrations with American guidelines (Threshold Effect Level: TEL and Probable Effect Level: PEL) showed that biological effects could be occasionally observed for cadmium, chromium, lead and nickel levels but frequently observed for copper and zinc levels. Sediment quality was shown to be excellent for cobalt and manganese but medium to bad for cadmium, chromium, copper, lead, nickel and zinc regardless of sites.     

Determination of reaction rate constants for phenol oxidation using SnO2/Ti anodes coupled with activated carbon adsorption in the presence of TiO2 as catalyst

Series of experiments for phenol degradation with assistance of TiO2 catalyst at pH of 6.5 and temperature of 25 degrees C were conducted using a lab-scale electrochemical reactor constructed in our laboratory. According to the results, at the presence of the TiO2 catalyst the removal of phenol was increased and first-order kinetics could describe the evolution of phenol concentration. For inspecting the relationship between rate constants and dosage of TiO2, two possible kinetics were proposed in this study. Contrasted to the abundant experimental data, a reasonable kinetics was obtained for the estimation of phenol concentration effluent during continuous flow of raw wastewater, especially when the TiO2 dosage was less than 0.5g L(-1). The model obtained from these experiments could employed for the calculation of rate constants at different TiO2 dosage and the necessary dosage of catalyst when a discharge standard was designed.     

Simple and efficient ion imprinted polymer for recovery of uranium from environmental samples

Ion imprinted polymer material (IIP) was prepared by forming ternary complexes of uranyl imprint ion with 1-(prop-2-en-1-yl)-4-(pyridin-2-ylmethyl)piperazine and methacrylic acid followed by thermal copolymerization with ethylene glycol dimethacrylate as the cross-linking monomer in the presence of 1,1'-azobis(cyclohexanecarbonitrile) initiator and 2-methoxy ethanol porogenic solvent. HCl solution (5 mol/L) was used to leach out the uranyl template ion from the IIP particles. Similarly, the control polymer (CP) material was also prepared exactly under the same conditions as the IIP but without the uranyl ion template. Various parameters such as solution pH, initial concentration, aqueous phase volume, sorbent dosage, contact time and leaching solution volumes were investigated. SEM, IR and BET-surface area and pore size analysis were used for the characterization of IIP and CP materials. The extraction efficiency of the IIP and CP was compared using a batch and SPE mode of extraction. The optimal pH for quantitative removal is 4.0-8.0, sorbent amount is 20 mg, contact time is 20 min and the retention capacity is 120 mg of uranyl ion per g of IIP. The IIP prepared demonstrated superior selectivity towards coexisting cations and therefore it can be used for selective removal of uranium from complex matrices.     

Plant algae method for arsenic removal from arsenic contaminated groundwater

Field studies were carried out in Urumqi River Basin in Northwest China. The study focused on experimentation on a plant algae method that was tested by taking various water chemistries into consideration. The results from a greenhouse experiment evaluated for four doses of P (0, 100, 200, and 300 μmol/L) using two ferns (30 and 60 day old) on 15 L of contaminated groundwater per plant revealed that the biomass of 30-day old ferns gained was higher than 60-day fern. As solution-P increased from 0 to 450 μmol/L, Phosphorus concentration in the fronds increased from 1.9 to 3.9 mg/kg and 1.95 to 4.0 mg/kg for 30-d and 60-d ferns respectively. This study showed that the plant algae method may be a good solution to maximize arsenic uptake in the short term under normal climatic conditions.     

A randomized trial to assess the effectiveness of an infant home safety programme

The aim of this study was to test an intervention aimed at addressing the risk of injury in infants 2 - 12 months of age. A non-blinded, randomized controlled trial was conducted, whereby parents were randomly assigned to either a control or one of two intervention groups. Parents completed questionnaires regarding safety behaviours and injuries at the 2 (baseline), 6 and 12 month immunization visit at the community health unit. During the 2 month visit to the health unit, the two intervention groups received a home safety kit containing nine items, an instructional brochure and a risk assessment checklist. Subjects randomized to the safety kit plus home visit group also received a standardized home visit from a community health nurse. Two of the 14 parental safety behaviours showed a significant increase in use among parents in the intervention groups. Neither of the interventions was associated with a reduction in parent-reported injuries among children. It was concluded that home visitation may provide a beneficial adjunct to the provision of safety devices and may increase use by parents.     

中国绝不是救世主

<正>我没想到,美国房市泡沫的破裂会让中国的美术家聚集地遭遇灭顶之灾。我原先并不知道,那些悬挂在美国的宾馆客房以及为青年人准备的简易房中的油画,居然都是由深圳大芬村生产的。     

是时候向银行说再见了

最近大银行受到的指责不少,从金融危机的责难到对其他各方的恐吓,从止赎混乱到摩根大通银行交易失态.当然这些都过于宏观,对于大多数人来说,大银行最让世人戳脊梁的应该是高收费和相当差的服务质量.幸运的是,这个时候出现了银行的替代品.     

什么可以阻止云计算的发展浪潮？

随着云计算在近十年间的迅猛发展,中小规模企业取得了重要的成就,大型私营部门组织和各国政府将其计算领域的重要部分转移至云计算方向。随着移动应用,如智能手机和芯片的迅速扩张,消费者也不甘落后地紧随发展步伐。从某种意义上说,我们已经在云计算领域开展了一些工作。是否有什么事物可以阻止云计算的发展浪潮？