The effect of treatment time on the ionic liquid surface film formation: promising surface coating for Mg alloy AZ31

Mg alloys are attractive materials for medical devices. The main limitation is that they are prone to corrosion. A low toxicity surface coating that enables uniform, controlled corrosion at a desired rate (this usually means it must offer barrier functions for a limited time period) is desirable. Phosphate-based ionic liquids (ILs) are known to induce a coating that can reduce the corrosion rate of Mg alloys, Furthermore, some ILs are known to be biocompatible and therefore, controlling the corrosion behaviour of an Mg alloy and its surface biocompatibility can be achieved through adding an appropriate low toxic IL surface layer to the substrate. In this study, we have evaluated the cytotoxicity of three phosphate-based ILs to primary human coronary artery endothelial cells. Among them, tributyl(methyl)-phosphonium diphenylphosphate (P1,4,4,4dpp) shows the lowest cytotoxicity. Therefore, further work was aimed at developing an appropriate treatment method to produce a homogeneous and passive surface coating based on P1,4,4,4dpp IL, with the focus on investigating the effect of treatment time. The results showed that that the formation of IL coating on AZ31 has proceeded progressively, and treatment time plays an important role. An IL treatment at 100 °C with an extended treatment time of 5 h significantly enhanced corrosion resistance of the AZ31 alloy in simulated body fluid. Additionally, the corrosion morphology was uniform and there was no evidence of "localized pitting corrosion" observed. Such a performance makes this ionic liquid coating as a potential surface coating biodegradable Mg-based implants.

On the acoustic performance of a precast panel system made from environmentally sustainable concrete : application in sports hall buildings

The use of green building materials and products promotes conservation of non-renewable resources and help reduce associated environmental impacts. This article reports the acoustical performance of a precast panel system made largely from concrete waste material. Two major applications for such panels that are being investigated currently include walls and claddings to industrial and commercial buildings and sound barriers for urban freeways. In this study, the application of the concrete panels for optimizing reverberation time (RT) in sports halls is tested using numerical simulations. As an innovative approach, additional layers are added to the precast panels to improve their appearance. The absorption coefficients of the concrete panel improved significantly with the architectural finish. The material can be tuned according to the required peak frequency. The architectural finish helped reduce the RT for frequencies above 500 Hz. Its application to different types of ceilings revealed that the RT of curved ceiling reduced up to 40% compared to flat and hybrid ceiling. A comparison of wall and ceiling modifications in small, medium and large sports halls showed that medium-sized halls have better acoustical performance compared with small and large halls with ceiling as well as wall treatment.

On the multicast lifetime of WANETs with multibeam antennas : Formulation, algorithms, and analysis

We explore the multicast lifetime capacity of energy-limited wireless ad hoc networks using directional multibeam antennas by formulating and solving the corresponding optimization problem. In such networks, each node is equipped with a practical smart antenna array that can be configured to support multiple beams with adjustable orientation and beamwidth. The special case of this optimization problem in networks with single beams have been extensively studied and shown to be NP-hard. In this paper, we provide a globally optimal solution to this problem by developing a general MILP formulation that can apply to various configurable antenna models, many of which are not supported by the existing formulations. In order to study the multicast lifetime capacity of large-scale networks, we also propose an efficient heuristic algorithm with guaranteed theoretical performance. In particular, we provide a sufficient condition to determine if its performance reaches optimum based on the analysis of its approximation ratio. These results are validated by experiments as well. The multicast lifetime capacity is then quantitatively studied by evaluating the proposed exact and heuristic algorithms using simulations. The experimental results also show that using two-beam antennas can exploit most lifetime capacity of the networks for multicast communications. © 2013 IEEE.

Effects of milling time on powder packing characteristics and compressive mechanical properties of sintered Ti-10Nb-3Mo alloy

The influence of milling time on the powder packing characteristics and compressive mechanical properties of a biomedical Ti-10Nb-3Mo alloy (wt.%) was investigated. Ball milling was performed on elemental metal powders at different milling times of 0 (blended), 2, 4, 6, 8, and 10 h. This article demonstrates that despite the beneficial effects of ball milling technique in the mechanical alloying of the Ti-based alloy, the ball-milled powders synthesized at longer milling times can adversely affect the packing density and significantly diminish the compressive mechanical properties of the sintered powders. Crown

The before and after effect of the Olympic games on the host city's property market : the Sydney experience

This research evaluated the impact of the Olympic Games on the host city's residential property market, both before and after the Games. Using a time  series approach between 1990 and 2003, this paper examines various indicators to measure the effect of the 2000 Olympics on the Sydney property market. The research shows that although the Olympics were held for only ten days, its influence on the surrounding market in a direct and indirect manner was substantial. It appears that the lasting effect of the Games on the property market remained strongest in the general vicinity of the Olympic Village, and then gradually weakened over time in areas located further away from this precinct. It emphasised the role of urban planning both before and after the event, and how to use a major sporting event to gentrify a suburb.

The influence of time since fire and distance from fire boundary on the distribution and abundance of arboreal marsupials in Eucalyptus regnans-dominated forest in the Central Highlands of Victoria

The impact of time since fire after two consecutive wildfires 44 years apart (1939 and 1983) within the same area, and the distance from the fire boundary «100 m or 500-2000 m), were investigated in relation to the distribution and abundance of arboreal marsupials in 1994. Arboreal marsupials were censused by stagwatching and spotlighting in two relatively young age classes of mountain ash (Eucalyptus regnans) dominated forest in the Central Highlands of Victoria. Five species of arboreal marsupial were detected, but only three were detected in sufficient numbers to determine habitat preferences. Petauroides volans (greater glider) was statistically more abundant in 1939 regrowth forests, while Trichosurus caninus (mountain brushtail possum) showed no significant preference for either age class of forest. All but one record of Gymnobelideus leadbeateri (Leadbeater's possum) came from young forest, though the effect of age-class was not statistically significant. Distance from fire boundary explained little or no variation in mammal distribution or abundance. While the actual number of hollow-bearing trees was similar in both age classes of forest, the long-term lifespan of hollow-bearing trees in more recently burnt forest is predicted to be lower than in unburnt or not recently burnt forest. Post-fire salvage logging following the 1983 wildfires appears to have reduced the number of hollow-bearing trees at sites burnt in 1983.

On the extent of speculative activity in the Indian stock market during badla and post-badla period

The authors test the existence of speculative activity in the Indian stock market during badla and post-badla period. They further investigate whether speculative activity migrated to single stocks futures market after banning of badla system. In both the tests it is found that there is no evidence of strong speculative activity in the Indian market. The research raises some questions on the regulators decision of banning badla system and sheds some light on the future decisions with respect to single stock futures market.

The effect of repeated pulses of light at the same time on period responses of the rat circadian pacemaker.

A consequence of simple velocity-based models is that, in response to light pulses, the circadian period should adjust inversely to phase. In addition, because of the interaction of circadian period and phase response, earlier circadian period changes should modify later circadian period changes. The literature contains few mentions of response curves of circadian period responses following light pulses. Rats were exposed to four pulses of light (60 minutes, 1000 lux) at the same circadian time, a minimum of 26 days apart; we assessed period responses and possible bias in the period-response curve. Modulation of circadian period following light-induced phase responses was examined by assessing the period of running wheel activity onset. Phase and circadian period were not consistently found to share an inverse relationship. Moreover, biases in initial period tended to be increased by the experimental protocol regardless of circadian time of pulse. Rats with a short initial (highvelocity) period had a lengthened period, while rats with a long initial period (low velocity) tended to have a reduce period. However, rats with a long initial period were phase delay biased, not phase advance biased. These results do not support a simple velocity model of the pacemaker.

Further evidence on the corporate use of derivatives in Australia : the case of foreign currency and interest rate instruments

In a recent issue of this journal Nguyen and Faff (2002) reported on an empirical exploration of the motives behind the aggregate use of financial derivatives by Australian companies. Employing the same sample of firms, the current paper extends their analysis to investigate similar issues, this time focussing separately on foreign currency and interest rate derivatives. At a specific level, our results reveal the following. A firm is more likely to use foreign currency derivatives if it is large and has more debt in its capital structure. Interest rate derivatives, on the other hand, are more likely to be used if a firm is larger, more levered, more liquid and pays higher dividends. These results are consistent with existing hedging theories. Market to book value (proxying growth opportunities), however, portrays an inconsistent relationship with the likelihood of interest rate derivative usage. When it comes to the extent of usage, a firm uses foreign currency derivatives more extensively if it is smaller, pays higher dividends and has more debt. Similarly, interest rate derivatives are used more extensively to address a high level of debt and a high dividend payout policy. At a general level, the current study confirms the core finding of Nguyen and Faff (2002), namely, that Australian companies use derivatives with a view to value maximisation.

The impact of Porter's strategy types on the role of market research and customer relationship management

Purpose – This paper seeks to investigate the influence of Porter’s strategy types on the use of customer relationship management (CRM) techniques and traditional market research, against theoretical and empirical evidence that differences in strategy types may result in variation in favoured marketing information sources and procedure.

Design/methodology/approach – Depth interviews generated a series of scale items, which were combined with others derived from the literature in a questionnaire measuring strategy types, the roles of market research, and the characteristics of CRM systems. Responses were obtained from 240 senior marketing managers in Australia, and applied to the testing of five research propositions.

Findings – ANOVA found no differences in CRM usage among the strategy types. Variation was widespread, however, in four roles of traditional market research: enhancing strategic decision making, increasing usability of existing data, presenting plans to senior management, and achieving productivity and political outcomes.

Research limitations/implications – Future researchers using the Porter strategic types should separate “marketing differentiators” from “product differentiators” because they function and compete differently.

Practical implications – All organisations can benefit from CRM systems, but “marketing differentiators” exhibit a relatively higher usage of traditional market research. This is likely to be because they compete by creating softer product differences, while others do so on harder characteristics such as price or product functionality.

Originality/value – This is the first study to use the Porter types to explain differences between the roles and uses of market research and CRM within organisations.

Effect of cage colour and light environment on the skin colour of Australian Snapper Pagrus auratus (Bloch & Schneider, 1801)

A two-factor experiment was performed to evaluate the effects of cage colour (black or white 0.5 m³ experiment cages) and light environment (natural sunlight or reduced level of natural sunlight) on the skin colour of darkened Australian snapper. Each treatment was replicated four times and each replicate cage was stocked with five snapper (mean weight=351 g). Snapper exposed to natural sunlight were held in experimental cages located in outdoor tanks. An approximately 70% reduction in natural sunlight (measured as PAR) was established by holding snapper in experimental cages that were housed inside a 'shade-house' enclosure. The skin colour of anaesthetized fish was measured at stocking and after a 2-, 7- and 14-day exposure using a digital chroma-meter (Minolta CR-10) that quantified skin colour according to the L*a*b* colour space. At the conclusion of the experiment, fish were killed in salt water ice slurry and post-mortem skin colour was quantified after 0.75, 6 and 22 h respectively. In addition to these trials, an ad hoc market appraisal of chilled snapper (mean weight=409 g) that had been held in either white or in black cages was conducted at two local fish markets. Irrespective of the sampling time, skin lightness (L*) was significantly affected by cage colour (P<0.05), with fish in white cages having much higher L* values (L*≈64) than fish held in black cages (L*≈49). However, the value of L* was not significantly affected by the light environment or the interaction between cage colour and the light environment. In general, the L* values of anaesthetized snapper were sustained post mortem, but there were linear reductions in the a* (red) and b* (yellow) skin colour values of chilled snapper over time. According to the commercial buyers interviewed, chilled snapper that had been reared for a short period of time in white cages could demand a premium of 10–50% above the prices paid for similar-sized snapper reared in black cages. Our results demonstrate that short-term use of white cages can reduce the dark skin colour of farmed snapper, potentially improving the profitability of snapper farming.

`Out on the borderlands`: Time, generation and personal agency in women`s lives

What tools can we use in attempting to understand the recurring patterns of some girls’ early school leaving and consequent exclusion from well-paid employment? From which disciplinary fields can we take them? Using Bourdieu’s concept of the ‘scholastic point of view’ - the inherent intellectual bias of a discipline, in his case sociology - as a springboard, we suggest that if one turns to different ‘fields’, approaches might be found which point towards differing perspectives. This article brings Bourdieu into dialogue with the work of feminist historians and their conceptual tools. Carolyn Steedman’s notion of the politics of envy and Sally Alexander’s appropriation from psychoanalysis of the idea of repetition offer generative ways of exploring the ‘unthought categories of thought which delimit the thinkable and predetermine the thought’ (Bourdieu and Wacquant, 1992: 40). In their focus on gender, they have much in common with feminist sociologists’ responses to Bourdieu’s work, suggesting that a gendered ‘perspective’ offers a way of avoiding the ‘singular viewpoint’ inherent in any one discipline.

The influence of polymerization time and dopant concentration on the absorption of microwave radiation in conducting polypyrrole coated textiles

Temperature changes in conducting polypyrrole/para-toluene-2-sulphonic acid (PPy/pTSA) coated nylon textiles due to microwave absorption in the 8–9 GHz and 15–16 GHz frequency ranges were obtained by a thermography station during simultaneous irradiation of the samples. The temperature values are compared and related to the amounts of reflection, transmission and absorption obtained with a non-contact free space transmission technique, indicating a relationship between microwave absorption and temperature increase. Non-conductive samples showed no temperature increase upon irradiation irrespective of frequency range. The maximum temperature difference of around 4 °C in the conducting fabrics relative to ambient temperature was observed in samples having 48% absorption and 26.5 ± 4% reflection. Samples polymerized for 60 or 120 min with a dopant concentration of 0.018 mol/l or polymerized for 180 min with a dopant concentration of 0.009 mol/l yielded optimum absorption levels. As the surface resistivity decreased and the reflection levels increased, the temperature increase upon irradiation reduced.

Effects of starvation and water quality on the purging process of farmed Murray cod ( Maccullochella peelii peelii )

The aim of this study was to determine the effects of starvation and water quality during the purging process on the biometric parameters, fatty acids, and flavor volatiles of Murray cod farmed in a recirculation system. Market size Murray cod, at the end of the grow-out stage, were divided into eight treatments. The treatments were either fed/starved (F or S) and kept in clean water (CW: CWF2, CWS2, CWF4, and CWS4) or fed/starved and kept in recycled water (RW: RWF2, RWS2, RWF4, and RWS4) for either 2 or 4 weeks. Fish were sampled at 0, 2, and 4 week intervals. Food deprivation was responsible for a significant (P < 0.05) weight loss compared to that of fed treatments. The same was observed for the condition factor (K), hepatosomatic index (HSI), and dress-out percentage (DP). No significant changes were, however, observed in the visceral fat index (VFI). Saturated fatty acids (SFA) were highest in RWF4 and lowest in CWS4 (P < 0.05), while monounsaturated fatty acids (MUFA) were lowest in CWF4 (P < 0.05). Starvation did not affect the flavor volatile compounds, which were mainly affected by changes in water quality. Specifically, total aldehyde (% w/w) content was significantly (P < 0.05) affected by water quality, but the time of purging was not responsible for any noteworthy differences. This study was able to separate the effects of starvation and water quality, in the purging process, on the final eating quality of farmed market size Murray cod. It is concluded that because of the inevitable weight loss during starvation, Murray cod should be fed during the purging stage but kept in clean water and deprived of food only for the time necessary to empty the gastro-intestinal tract.