101 resultados para saline medium


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Biodegradation of poorly soluble polycyclic aromatic hydrocarbons (PAHs) has been a challenge in bioremediation. In recent years, surfactant-enhanced bioremediation of PAH contaminants has attracted great attention in research. In this study, biodegradation of phenanthrene as a model PAHs solubilized in saline micellar solutions of a biodegradable commercial alcohol ethoxylate nonionic surfactant was investigated. The critical micelle concentration (CMC) of the surfactant and its solubilization capacity for phenanthrene were examined in an artificial saline water medium, and a type of marine bacteria, Neptunomonas naphthovorans, was studied for the biodegradation of phenanthrene solubilized in the surfactant micellar solutions of the saline medium. It is found that the solubility of phenanthrene in the surfactant micellar solutions increased linearly with the surfactant concentrations, but, at a fixed phenanthrene concentration, the biodegradability of phenanthrene in the micellar solutions decreased with the increase of the surfactant concentrations. This was attributed to the reduced bioavailability of phenanthrene, due to its increased solubilization extent in the micellar phase and possibly lowered mass transfer rate from the micellar phase into the aqueous phase or into the bacterial cells. In addition, an inhibitory effect of the surfactant on the bacterial growth at high surfactant concentrations may also play a role. It is concluded that the surfactant largely enhanced the solubilization of phenanthrene in the saline water medium, but excess existence of the surfactant in the medium should be minimized or avoided for the biodegradation of phenanthrene by Neptunomonas naphthovorans.

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It is believed that the recent emergence of electronic commerce (e-commerce) in the early '90s could provide different opportunities to small to medium-sized enterprises (SME's) in overcoming part of their technological, environmental, organizational, and managerial inadequacies. However, recent research portrays a gloomy picture about e-commerce uptake and use in SME's. Therefore, the implication here is twofold. Initially, there is a need to generate more e-commerce research that could penetrate much deeper into main impending issues pertaining to the SME’s in their potential uptake and use of e-commerce. On the other hand, e-commerce is characterized of being embryonic but growing very fast and fragmented across the different disciplines, which makes the task of capturing its different perspectives a very complex one. The preceding two implications represent the greatest challenge for researchers and professionals interested in undertaking e-commerce research in SME’s. In line with the above implications, the first objective of this research aims at capturing the different e-commerce perspectives from the SMEs' point of view, and the second objective aims at capturing the e-commerce perspective from the theoretical and the methodological point of view. Addressing the preceding implications in this research could shed some light into some of the gray areas in the e-commerce research in SMEs.

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Resistance to change has long been recognised as a critically important factor that can influence the success or otherwise of implementing any 'technological innovation. Information technology (IT) focused interventions, for example, business process re-engineering (BPR) and enterprise resource planning (ERP), are often quoted as examples of costly failures, with reported levels of dissatisfaction ·with strategic IT investments ranging from 20-70 percent and that employee resistance was to blame. The intention of this chapter is to rethink resistance. The author suggests that resistance remains to this day a complex, multifaceted phenomenon that continues to affect the outcomes of change, both negatively and positively. Although research has procured a solid understanding of resistance- and the benefits that can accrue to an organisation through its proper utilisation, it appears that the classical adversarial approach remains the dominant means ofmanaging resistance because such learning is not reflected in modern management techniques. The author concludes that as companies in every industry are now translating the power and possibilities 0/ e-business into strategic and operational realities, newapproaches in change managementare required to help organisations to understand the complex dynamics o/technological innovation and especially the multifaceted nature o/resistance.

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All of the plants and animals that make up freshwater aquatic communities are affected by salinity. Many taxa possess morphological, physiological and life-history characteristics that provide some capacity for tolerance, acclimatisation or avoidance. These characteristics impart a level of resilience to freshwater communities.     To maintain biodiversity in aquatic systems it is important to manage the rate, timing, pattern, frequency and duration of increases in salinity in terms of lethal and sublethal effects, sensitive life stages, the capacity of freshwater biota to acclimatise to salinity and long-term impacts on community structure.     We have limited understanding of the impacts of saline water management on species interactions, food-web structures and how elevated salinity levels affect the integrity of communities. Little is known about the effect of salinity on complex ecosystem processes involving microbes and microalgae, or the salinity thresholds that prevent semi-aquatic and terrestrial species from using aquatic resources. Compounding effects of salinity and other stressors are also poorly understood.    Our current understanding needs to be reinterpreted in a form that is accessible and useful for water managers. Because of their complexity, many of the remaining knowledge gaps can only be addressed through a multidisciplinary approach carried out in an adaptive management framework, utilising decision-making and ecological risk assessment tools.

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Grain refinement during and after hot isothermal deformation of a medium carbon steel has been investigated. The average austenite grain size decreased with an increase in strain for the hot deformed and recrystallised material, with refinement extending beyond the strain for the peak stress. A window of strain that corresponds to transition from classical static to metadynamic recrystallisation was observed in respect to the recrystallised material. Within this post-dynamic transition window the strain at which strain independent softening occurs was different for different volume fractions of the recrystallised material. This led to a new terminology corresponding to initiation of strain independent softening. For the alloy of this study, strain independent softening for the start of post-deformation recrystallisation occurred near the strain to the peak stress. The strain corresponding to complete metadynamic recrystallisation, which was defined as when all levels of recrystallisation were strain independent, was much greater than the strain for the peak stress.

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Quality methods in Australian industry gained much attention in the late 1980s and for most of the 1990s. In particular, quality methods such as quality systems and quality system certification had prominence, as Governments and large private sector firms attempted to improve their supply-chains. The aim of this paper is to demonstrate a rigorous and holistic approach to investigating the applicability of quality methods in Australian small and medium sized enterprises (SMEs). It describes the research framework developed to further investigate the impact of quality methods on Australian SMEs, and illustrates how the framework leads to a broader exploratory study.

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In New Zealand, small to medium-sized enterprises (SMEs) play a very important role in the economy by their contribution to both employment and also to gross domestic product. Addressing issues pertinent to SMEs is of paramount importance in driving this sector forward. Information Technology (IT) emerges as one main enabler for SMEs in automating their operations, seeking new opportunities and enhancing their strategic business positioning in local and international markets. However, the dynamic nature of IT and inability of SMEs, due to problems inherent in their size and structure, makes it difficult for them to take appropriate decisions to benefit from the IT technologies. The advent of eCommerce (EC) has only compounded this problem. One way out of this complex situation is to outsource the IT and EC technology requirements by the SMEs. This study endeavours to identify the pattern of IT and EC outsourcing issues of SMEs within New Zealand. It reveals that the main driver for IT outsourcing is access to expertise and used mainly for maintenance purposes only. The study also identifies the problems in IT outsourcing and makes suggestions for further research in this crucial sector.

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This paper delivers the findings from a study conducted to investigate Australian SMEs and e-business security. The study established the attitudes and concerns of a sample of Australian Small and Medium-sized Enterprises (SMEs) towards the use of e-business within their operational environment using the members of the Geelong Chamber of Commerce as a base for survey participants. The results focus on e-business security and identifying mechanisms that SMEs use to safeguard their e-business systems.

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Managing project quality is becoming focal issue in major enterprises as popular quality programs from International Standard Organization (ISO) such as ISO9000 certification processes gain momentum. Large organizations as well as small-medium enterprises (SMEs) seem to implement this program, albeit for varied reasons. In this paper, we have reported the findings from an action research project conducted in SMEs who are implementing quality management. The findings indicate that external pressures such as regulations, competition and perceived success - defined on their own parameters, may be the drivers and the certification does not necessarily result in better performance. We are in the process of developing a cost-effective guideline/framework - based on this research, for SMEs involved in the certification process. In addition, the results are aimed at informing academia as well as certification bodies of specific concerns with SMEs.