106 resultados para volatile
Resumo:
There is an ongoing level of organizational-wide change (such as empowerment and downsizing) occurring within the Australian health care sector. However, there is a paucity of empirical evidence on how public and nonprofit sector nurses cope with these organizational-wide change initiatives and their consequences on individual and work outcomes. This will be the primary aim of the current paper. To this end, a path model is developed base on an integration of existing theoretical perspectives on occupational stress, change management, and person-organizational fit. Data were collected from 252 public and not-for-profit sector nurses. The path analysis suggests that public and nonprofit nurses experience positive and negative change initiatives. Negative change initiatives resulted in an increase in the level of administrative-related stressors. Nurses with more congruent values report less experience with administrative stressors. As nurses experienced more administrative stressors, they tend to report more job dissatisfaction. Nurses whose values were more congruent during organizational change reported higher level of psychological wellbeing. Nurses who were had higher level of psychological wellbeing were found to have higher job satisfaction, which subsequently led to a higher level of organizational commitment.
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This paper describes and explains the social worlds of a group of young Murris who are engaged in chroming (paint sniffing) and who sleep rough in inner Brisbane. In particular, the paper considers the ways young Indigenous drug users describe their marginalisation from wider society and its structures of opportunity, but it also includes some reflections from their youth worker and a young man who frequents the young people’s squat. The paper demonstrates the centrality of racism and material disadvantage to the experience of a group of young Aboriginal and Torres Strait Islander sniffers, a perspective largely unreflected in the literature on Indigenous volatile substance misuse. Further, the young people’s ways of interacting with the broader society are described to explain the ways their rejection of mainstream norms form a significant political response to their marginality and reflect, at least in part, the wider Indigenous historical experience. The work draws on theories of alienation and subculture to analyse the young people’s descriptions of their social estrangement and the formation of the ‘paint sniffer group’. It is concluded that paint sniffing among urban Indigenous youth is, at least in part, an obnoxious and encoded distillation of a wider Indigenous rebuttal of broader societal norms, and that the dominant — normalising — modes of treatment risk further alienating an already oppositional group of young people.
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Target date retirement funds have gained favor with retirement plan investors in recent years. Typically, these funds initially have a high allocation to stocks but move towards less volatile assets, such as bonds and cash, as the target retirement date approaches. Empirical research has generally found that a switch to low-risk assets prior to retirement can reduce the risk of confronting the most extreme negative outcomes. This article questions the rationale for lifecycle switching based solely on age or target retirement date as is the prevalent practice among target date funds. The authors argue that a dynamic switching strategy, which takes into consideration achieved investment returns, will produce superior returns for most investors compared to conventional lifecycle switching. In this article, the authors put forward a dynamic lifecycle switching strategy that is conditional on the attainment of the plan member's wealth accumulation objective at every stage of switching.
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Concepts used in this chapter include: Thermoregulation:- Thermoregulation refers to the body’s sophisticated, multi-system regulation of core body temperature. This hierarchical system extends from highly thermo-sensitive neurons in the preoptic region of the brain proximate to the rostral hypothalamus, down to the brain stem and spinal cord. Coupled with receptors in the skin and spine, both central and peripheral information on body temperature is integrated to inform and activate the homeostatic mechanisms which maintain our core temperature at 37oC1. Hyperthermia:- An imbalance between the metabolic and external heat accumulated in the body and the loss of heat from the body2. Exertional heat stroke:- A disorder of excessive heat production coupled with insufficient heat dissipation which occurs in un-acclimated individuals who are engaging in over-exertion in hot and humid conditions. This phenomenon includes central nervous system dysfunction and critical dysfunction to all organ systems including renal, cardiovascular, musculoskeletal and hepatic functions. Non-exertional heat stroke:- In contrast to exertional heatstroke as a consequence of high heat production during strenuous exercise, non-exertional heatstroke results from prolonged exposure to high ambient temperature. The elderly, those with chronic health conditions and children are particularly susceptible.3 Rhabdomylosis:- An acute, sometimes fatal disease characterised by destruction of skeletal muscle. In exertional heat stroke, rhabdomylosis occurs in the context of strenuous exercise when mechanical and/or metabolic stress damages the skeletal muscle, causing elevated serum creatine kinease. Associated with this is the potential development of hyperkalemia, myoglobinuria and renal failure. Malignant hyperthermia:- Malignant hyperthermia is “an inherited subclinical myopathy characterised by a hypermetabolic reaction during anaesthesia. The reaction is related to skeletal muscle calcium dysregulation triggered by volatile inhaled anaesthetics and/or succinylcholine.”4 Presentation includes skeletal muscle rigidity, mixed metabolic and respiratory acidosis, tachycardia, hyperpyrexia, rhabdomylosis, hyperkalaemia, elevated serum creatine kinease, multi-organ failure, disseminated intravascular coagulation and death.5
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Fruit flies require protein for reproductive development and actively feed upon protein sources in the field. Liquid protein baits mixed with insecticide are used routinely to manage pest fruit flies, such as Bactrocera tryoni (Froggatt). However, there are still some gaps in the underpinning science required to improve the efficacy of bait spray technology. The spatial and temporal foraging behaviour of B. tryoni in response to protein was investigated in the field. A series of linked trials using either wild flies in the open field or laboratory-reared flies in field cages and a netted orchard were undertaken using nectarines and guavas. Key questions investigated were the fly's response to protein relative to: height of protein within the canopy, fruiting status of the tree, time of day, season and size of the experimental arena. Canopy height had a significant response on B. tryoni foraging, with more flies foraging on protein in the mid to upper canopy. Fruiting status also had a significant effect on foraging, with most flies responding to protein when applied to fruiting hosts. B. tryoni demonstrated a repeatable diurnal response pattern to protein, with the peak response being between 12:00–16:00 h. Season showed significant but unpredictable effects on fruit fly response to protein in the subtropical environment where the work was undertaken. Relative humidity, but not temperature or rainfall, was positively correlated with protein response. The number of B. tryoni responding to protein decreased dramatically as the spatial scale increased from field cage through to the open field. Based on these results, it is recommend that, to be most effective, protein bait sprays should be applied to the mid to upper canopies of fruiting hosts. Overall, the results show that the protein used, an industry standard, has very low attractancy to B. tryoni and that further work is urgently needed to develop more volatile protein baits.
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Convergence of pervasive technologies, techno-centric customers and the emergence of digitized channels, overabundance of user friendly retail applications are having a profound impact on retail experience, leading to the advent of ‘everywhere retailing’. With the rapid uptake of digital complimentary assets and smart mobile applications are revolutionizing the relationship of retailers with their customers and suppliers. Retail firms are increasingly investing substantial resources on dynamic Customer Relationship Management systems (D-CRM / U-CRM) to better engage with customers to sense and respond quickly (Agility of the firm) to their demands. However, unlike traditional CRM systems, engagement with U-CRM systems requires that firms be hyper sensitive to volatile customer needs and wants. Following the notions of firm agility, this study attempts to develop a framework to understand such unforeseen benefits and issues of U-CRM. This research-in-progress paper reports an a-priory framework including 62 U-CRM benefits derived through an archival analysis of literature.
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Boron–nitrogen containing compounds with high hydrogen contents as represented by ammonia borane (NH3BH3) have recently attracted intense interest for potential hydrogen storage applications. One such compound is [(NH3)2BH2]B3H8 with a capacity of 18.2 wt% H. Two safe and efficient synthetic routes to [(NH3)2BH2]B3H8 have been developed for the first time since it was discovered 50 years ago. The new synthetic routes avoid a dangerous starting chemical, tetraborane (B4H10), and afford a high yield. Single crystal X-ray diffraction analysis reveals N–Hδ+Hδ−–B dihydrogen interactions in the [(NH3)2BH2]B3H8·18-crown-6 adduct. Extended strong dihydrogen bonds were observed in pure [(NH3)2BH2]B3H8 through crystal structure solution based upon powder X-ray analysis. Pyrolysis of [(NH3)2BH2]B3H8 leads to the formation of hydrogen gas together with appreciable amounts of volatile boranes below 160 °C.
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Odours emitted by flowers are complex blends of volatile compounds. These odours are learnt by flower-visiting insect species, improving their recognition of rewarding flowers and thus foraging efficiency. We investigated the flexibility of floral odour learning by testing whether adult moths recognize single compounds common to flowers on which they forage. Dual choice preference tests on Helicoverpa armigera moths allowed free flying moths to forage on one of three flower species; Argyranthemum frutescens (federation daisy), Cajanus cajan (pigeonpea) or Nicotiana tabacum (tobacco). Results showed that, (i) a benzenoid (phenylacetaldehyde) and a monoterpene (linalool) were subsequently recognized after visits to flowers that emitted these volatile constituents, (ii) in a preference test, other monoterpenes in the flowers' odour did not affect the moths' ability to recognize the monoterpene linalool and (iii) relative preferences for two volatiles changed after foraging experience on a single flower species that emitted both volatiles. The importance of using free flying insects and real flowers to understand the mechanisms involved in floral odour learning in nature are discussed in the context of our findings.
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Nitrous oxide emissions from soil are known to be spatially and temporally volatile. Reliable estimation of emissions over a given time and space depends on measuring with sufficient intensity but deciding on the number of measuring stations and the frequency of observation can be vexing. The question of low frequency manual observations providing comparable results to high frequency automated sampling also arises. Data collected from a replicated field experiment was intensively studied with the intention to give some statistically robust guidance on these issues. The experiment had nitrous oxide soil to air flux monitored within 10 m by 2.5 m plots by automated closed chambers under a 3 h average sampling interval and by manual static chambers under a three day average sampling interval over sixty days. Observed trends in flux over time by the static chambers were mostly within the auto chamber bounds of experimental error. Cumulated nitrous oxide emissions as measured by each system were also within error bounds. Under the temporal response pattern in this experiment, no significant loss of information was observed after culling the data to simulate results under various low frequency scenarios. Within the confines of this experiment observations from the manual chambers were not spatially correlated above distances of 1 m. Statistical power was therefore found to improve due to increased replicates per treatment or chambers per replicate. Careful after action review of experimental data can deliver savings for future work.
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Energy prices are highly volatile and often feature unexpected spikes. It is the aim of this paper to examine whether the occurrence of these extreme price events displays any regularities that can be captured using an econometric model. Here we treat these price events as point processes and apply Hawkes and Poisson autoregressive models to model the dynamics in the intensity of this process.We use load and meteorological information to model the time variation in the intensity of the process. The models are applied to data from the Australian wholesale electricity market, and a forecasting exercise illustrates both the usefulness of these models and their limitations when attempting to forecast the occurrence of extreme price events.
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Generally, the magnitude of pollutant emissions from diesel engines is ultimately coupled to the structure of fuel molecules. The presence of oxygen, level of unsaturation and the carbon chain length of respective molecules influence the combustion chemistry. It is speculated that increased oxygen content in the fuel may lead to the increased oxidative potential (Stevanovic, S. 2013). Also, upon the exposure to UV and ozone in the atmosphere, the chemical composition of the exhaust is changed. The presence of an oxidant and UV is triggering the cascade of photochemical reactions as well as the partitioning of semi-volatile compounds between the gas and particle phase. To gain an insight into the relationship between the molecular structures of the esters, their volatile organic content and the potential toxicity of diesel exhaust particulate matter, measurements were conducted on a modern common rail diesel engine. This research also investigates the contribution of atmospheric conditions on the transfer of semi-volatile fraction of diesel exhaust from the gas phase to the particle phase and the extent to which semi-volatile compounds (SVOCs) are related to the oxidative potential, expressed through the concentration of reactive oxygen species (ROS) (Stevanovic, S. 2013)...
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This thesis is a study of how the contents of volatile memory on the Windows operating system can be better understood and utilised for the purposes of digital forensic investigations. It proposes several techniques to improve the analysis of memory, with a focus on improving the detection of unknown code such as malware. These contributions allow the creation of a more complete reconstruction of the state of a computer at acquisition time, including whether or not the computer has been infected by malicious code.
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Despite the existence of air quality guidelines in Australia and New Zealand, the concentrations of particulate matter have exceeded these guidelines on several occasions. To identify the sources of particulate matter, examine the contributions of the sources to the air quality at specific areas and estimate the most likely locations of the sources, a growing number of source apportionment studies have been conducted. This paper provides an overview of the locations of the studies, salient features of the results obtained and offers some perspectives for the improvement of future receptor modelling of air quality in these countries. The review revealed that because of its advantages over alternative models, Positive Matrix Factorisation (PMF) was the most commonly applied model in the studies. Although there were differences in the sources identified in the studies, some general trends were observed. While biomass burning was a common problem in both countries, the characteristics of this source varied from one location to another. In New Zealand, domestic heating was the highest contributor to particle levels on days when the guidelines were exceeded. On the other hand, forest back-burning was a concern in Brisbane while marine aerosol was a major source in most studies. Secondary sulphate, traffic emissions, industrial emissions and re-suspended soil were also identified as important sources. Some unique species, for example, volatile organic compounds and particle size distribution were incorporated into some of the studies with results that have significant ramifications for the improvement of air quality. Overall, the application of source apportionment models provided useful information that can assist the design of epidemiological studies and refine air pollution reduction strategies in Australia and New Zealand.
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In contemporary Western societies, the years between childhood and young adulthood are commonly understood to be (trans)formative in the reflexive project of sexual self-making (Russell et al. 2012). As sexual subjects in the making, youthful bodies, desires and sexual activities are often perceived as both volatile and vulnerable, thus subjected to instruction and discipline, protection and surveillance. Accordingly, young people’s sexual proximities are closely monitored by social institutions and ‘(hetero)normalising regimes’ (Warner 1999) for any signs that may compromise the end goal of development—a ‘normal’ reproductive heterosexual monogamous adult...
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Commercially available generic Superglue (cyanoacrylate glue) can be used as an alternative mounting medium for stained resin-embedded semithin sections. It is colourless and contains a volatile, quick-setting solvent that produces permanent mounts of semithin sections for immediate inspection under the light microscope. Here, we compare the use of cyanoacrylate glue for mounting semithin sections with classical dibutyl phthalate xylene (DPX) in terms of practical usefulness, effectiveness and the quality of the final microscopic image.