193 resultados para Existence of solutions


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Infrared and infrared emission spectroscopy were used to analyze the difference in structure and thermal behavior of two Chinese palygorskites. The position of the main bands identified in the infrared spectra of the palygorskites studied is similar for these two Chinese samples, but there are some differences in their intensity, which is significant. This discrepancy is attributed to various geological environments in different regions and the existence of impurities. The infrared emission spectra clearly show the structural changes and dehydroxylation of the palygorskites when the temperature is raised. The dehydration of the palygorskites is followed by the loss of intensity of the OH stretching vibration bands in the region 3600-3200 cm-1. Dehydroxylation is followed by the decrease in intensity in the bands between 3700 and 3550 cm-1. Dehydration of pure palygorskite was completed by 600 °C. Partial loss of coordinated water was observed at 400 °C. Infrared emission spectroscopy is an effective method to determine the stability of the mineral.

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International law’s capacity to influence state behaviour by regulating recourse to violence has been a longstanding source of debate among international lawyers and political scientists. On the one hand, sceptics assert that frequent violations of the prohibition on the use of force have rendered article 2(4) of the UN Charter redundant. They contend that national self-interest, rather than international law, is the key determinant of state behaviour regarding the use of force. On the other hand, defenders of article 2(4) argue first, that most states comply with the Charter framework, and second, that state rhetoric continues to acknowledge the existence of the jus ad bellum. In particular, the fact that violators go to considerable lengths to offer legal or factual justifications for their conduct – typically by relying on the right of self-defence – is advanced as evidence that the prohibition on the use of force retains legitimacy in the eyes of states. This paper identifies two potentially significant features of state practice since 2006 which may signal a shift in states’ perceptions of the normative authority of article 2(4). The first aspect is the recent failure by several states to offer explicit legal justifications for their use or force, or to report action taken in self-defence to the Security Council in accordance with Article 51. Four incidents linked to the global “war on terror” are examined here: Israeli airstrikes in Syria in 2007 and in Sudan in 2009, Turkey’s 2006-2008 incursions into northern Iraq, and Ethiopia’s 2006 intervention in Somalia. The second, more troubling feature is the international community’s apparent lack of concern over the legality of these incidents. Each use of force is difficult to reconcile with the strict requirements of the jus ad bellum; yet none attracted genuine legal scrutiny or debate among other states. While it is too early to conclude that these relatively minor incidents presage long term shifts in state practice, viewed together the two developments identified here suggest a possible downgrading of the role of international law in discussions over the use of force, at least in conflicts linked to the “war on terror”. This, in turn, may represent a declining perception of the normative authority of the jus ad bellum, and a concomitant admission of the limits of international law in regulating violence.

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Objective: The purpose of this study was to address (1) the existence of an association between menopausal status and the health-related quality of life (HRQOL) in Australian and Japanese women and (2) the relative contributions of menopausal status, modifiable lifestyle risk factors, health, and sociodemographic factors on HRQOL. Design: The Australian and Japanese Midlife Women's Health Study (AJMWHS) was a multisite, population-based study conducted in 2001 to 2002. Measures were conducted on data collected from a survey questionnaire used for a sample of women from Australia and Japan. HRQOL was assessed with seven subscales from the Short Form-36. Results: The differences seen in physical functioning, general health, and vitality are significant. The results support an effect of country of residence on physical functioning and general health. The impact of menopausal status on HRQOL was significantly associated with bodily pain and role-emotional. The country of residence did have a modifying effect on the relationship between menopausal status and physical functioning. After control for confounders, there was a significant difference between Australian and Japanese women for HRQOL. Menopausal status was not associated with HRQOL in the areas of general health and physical functioning. Modifiable lifestyle risk factors contributed more highly to HRQOL for the Australian women than for the Japanese women. If the women had a lowered body mass index, undertook physical activity, consumed dietary phytoestrogens, and used alcohol, their physical functioning seemed to be better. Differences were seen in the contributions to HRQOL in these areas, with lower body mass index in the Australian women and physical activity in the Japanese women being the highest predictors. Somatic and psychological symptoms seem to negatively affect both Japanese and Australian women's physical functioning, contributing more than sociodemographic factors, menopausal status, and behavioral determinants combined to general health and physical functioning. Conclusions: It is important that that consideration be given to incorporating the same tool within the cross-cultural design of studies so that comparisons between cultures and patterns of healthy aging can be made. The research suggests that there seems to be variations across Australian and Japanese midlife women in some areas of HRQOL and some factors that contribute to these areas.

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Background In contrast to pluripotent embryonic stem cells, adult stem cells have been considered to be multipotent, being somewhat more restricted in their differentiation capacity and only giving rise to cell types related to their tissue of origin. Several studies, however, have reported that bone marrow-derived mesenchymal stromal cells (MSCs) are capable of transdifferentiating to neural cell types, effectively crossing normal lineage restriction boundaries. Such reports have been based on the detection of neural-related proteins by the differentiated MSCs. In order to assess the potential of human adult MSCs to undergo true differentiation to a neural lineage and to determine the degree of homogeneity between donor samples, we have used RT-PCR and immunocytochemistry to investigate the basal expression of a range of neural related mRNAs and proteins in populations of non-differentiated MSCs obtained from 4 donors. Results The expression analysis revealed that several of the commonly used marker genes from other studies like nestin, Enolase2 and microtubule associated protein 1b (MAP1b) are already expressed by undifferentiated human MSCs. Furthermore, mRNA for some of the neural-related transcription factors, e.g. Engrailed-1 and Nurr1 were also strongly expressed. However, several other neural-related mRNAs (e.g. DRD2, enolase2, NFL and MBP) could be identified, but not in all donor samples. Similarly, synaptic vesicle-related mRNA, STX1A could only be detected in 2 of the 4 undifferentiated donor hMSC samples. More significantly, each donor sample revealed a unique expression pattern, demonstrating a significant variation of marker expression. Conclusion The present study highlights the existence of an inter-donor variability of expression of neural-related markers in human MSC samples that has not previously been described. This donor-related heterogeneity might influence the reproducibility of transdifferentiation protocols as well as contributing to the ongoing controversy about differentiation capacities of MSCs. Therefore, further studies need to consider the differences between donor samples prior to any treatment as well as the possibility of harvesting donor cells that may be inappropriate for transplantation strategies.

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Global and national agenda for quality education led to reform in Papua New Guinea (PNG) based on the provision of quality basic education. “Education for All” (EFA) is a worldwide emphasis on the review and restructure of existing curriculum and teacher training programs to provide quality education and quality life. The provision of quality education is seen as an investment in developing countries including PNG. Quality education is facilitated through structural and curriculum reform, and teacher education programs. One such influence on quality education in teacher education relates to perspectives of teaching. Existing research shows teachers’ beliefs and perceptions of teaching influence their practice (Kember & Kwan, 2000; Prosser & Trigwell, 2004). However, there is no research focusing on perspectives of teaching for elementary education in PNG. This single exploratory case study (Yin, 2009) investigated the perspectives of teaching of eighteen elementary teacher trainers and their five mentors in the context of an Australian university Bachelor of Early Childhood (in teacher education) degree programme. The study drew on an interpretivist paradigm to analyse journals, semi-structured interviews and course planning documents using a thematic approach to data analysis (Braun & Clark, 2006). The findings revealed that participants held perspectives of teaching related to teaching children and teaching adults. The perspective of teaching children described by the trainers and mentors was learning-centred (the focus is on what the teacher does); while the perspective of teaching adults was both learning-centred and learner-centred (the focus is on what the learner does). The learning-centred perspective is at odds with the learner-centred perspective espoused in the PNG reform. The perspectives of teaching adults reflected a culturally nuanced view; providing insights about how teaching and learning are understood in different sociocultural contexts. Based on these findings, the study proposes a perspective of teaching for elementary education in PNG known as culturally connected teaching. This perspective enables the co-existence of both the learning-centred and learner-centred perspectives of teaching in the PNG cultural context. This perspective has implications for teacher training and the communities involved in elementary education.

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Complex networks have been studied extensively due to their relevance to many real-world systems such as the world-wide web, the internet, biological and social systems. During the past two decades, studies of such networks in different fields have produced many significant results concerning their structures, topological properties, and dynamics. Three well-known properties of complex networks are scale-free degree distribution, small-world effect and self-similarity. The search for additional meaningful properties and the relationships among these properties is an active area of current research. This thesis investigates a newer aspect of complex networks, namely their multifractality, which is an extension of the concept of selfsimilarity. The first part of the thesis aims to confirm that the study of properties of complex networks can be expanded to a wider field including more complex weighted networks. Those real networks that have been shown to possess the self-similarity property in the existing literature are all unweighted networks. We use the proteinprotein interaction (PPI) networks as a key example to show that their weighted networks inherit the self-similarity from the original unweighted networks. Firstly, we confirm that the random sequential box-covering algorithm is an effective tool to compute the fractal dimension of complex networks. This is demonstrated on the Homo sapiens and E. coli PPI networks as well as their skeletons. Our results verify that the fractal dimension of the skeleton is smaller than that of the original network due to the shortest distance between nodes is larger in the skeleton, hence for a fixed box-size more boxes will be needed to cover the skeleton. Then we adopt the iterative scoring method to generate weighted PPI networks of five species, namely Homo sapiens, E. coli, yeast, C. elegans and Arabidopsis Thaliana. By using the random sequential box-covering algorithm, we calculate the fractal dimensions for both the original unweighted PPI networks and the generated weighted networks. The results show that self-similarity is still present in generated weighted PPI networks. This implication will be useful for our treatment of the networks in the third part of the thesis. The second part of the thesis aims to explore the multifractal behavior of different complex networks. Fractals such as the Cantor set, the Koch curve and the Sierspinski gasket are homogeneous since these fractals consist of a geometrical figure which repeats on an ever-reduced scale. Fractal analysis is a useful method for their study. However, real-world fractals are not homogeneous; there is rarely an identical motif repeated on all scales. Their singularity may vary on different subsets; implying that these objects are multifractal. Multifractal analysis is a useful way to systematically characterize the spatial heterogeneity of both theoretical and experimental fractal patterns. However, the tools for multifractal analysis of objects in Euclidean space are not suitable for complex networks. In this thesis, we propose a new box covering algorithm for multifractal analysis of complex networks. This algorithm is demonstrated in the computation of the generalized fractal dimensions of some theoretical networks, namely scale-free networks, small-world networks, random networks, and a kind of real networks, namely PPI networks of different species. Our main finding is the existence of multifractality in scale-free networks and PPI networks, while the multifractal behaviour is not confirmed for small-world networks and random networks. As another application, we generate gene interactions networks for patients and healthy people using the correlation coefficients between microarrays of different genes. Our results confirm the existence of multifractality in gene interactions networks. This multifractal analysis then provides a potentially useful tool for gene clustering and identification. The third part of the thesis aims to investigate the topological properties of networks constructed from time series. Characterizing complicated dynamics from time series is a fundamental problem of continuing interest in a wide variety of fields. Recent works indicate that complex network theory can be a powerful tool to analyse time series. Many existing methods for transforming time series into complex networks share a common feature: they define the connectivity of a complex network by the mutual proximity of different parts (e.g., individual states, state vectors, or cycles) of a single trajectory. In this thesis, we propose a new method to construct networks of time series: we define nodes by vectors of a certain length in the time series, and weight of edges between any two nodes by the Euclidean distance between the corresponding two vectors. We apply this method to build networks for fractional Brownian motions, whose long-range dependence is characterised by their Hurst exponent. We verify the validity of this method by showing that time series with stronger correlation, hence larger Hurst exponent, tend to have smaller fractal dimension, hence smoother sample paths. We then construct networks via the technique of horizontal visibility graph (HVG), which has been widely used recently. We confirm a known linear relationship between the Hurst exponent of fractional Brownian motion and the fractal dimension of the corresponding HVG network. In the first application, we apply our newly developed box-covering algorithm to calculate the generalized fractal dimensions of the HVG networks of fractional Brownian motions as well as those for binomial cascades and five bacterial genomes. The results confirm the monoscaling of fractional Brownian motion and the multifractality of the rest. As an additional application, we discuss the resilience of networks constructed from time series via two different approaches: visibility graph and horizontal visibility graph. Our finding is that the degree distribution of VG networks of fractional Brownian motions is scale-free (i.e., having a power law) meaning that one needs to destroy a large percentage of nodes before the network collapses into isolated parts; while for HVG networks of fractional Brownian motions, the degree distribution has exponential tails, implying that HVG networks would not survive the same kind of attack.

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True stress-strain curve of railhead steel is required to investigate the behaviour of railhead under wheel loading through elasto-plastic Finite Element (FE) analysis. To reduce the rate of wear, the railhead material is hardened through annealing and quenching. The Australian standard rail sections are not fully hardened and hence suffer from non-uniform distribution of the material property; usage of average properties in the FE modelling can potentially induce error in the predicted plastic strains. Coupons obtained at varying depths of the railhead were, therefore, tested under axial tension and the strains were measured using strain gauges as well as an image analysis technique, known as the Particle Image Velocimetry (PIV). The head hardened steel exhibit existence of three distinct zones of yield strength; the yield strength as the ratio of the average yield strength provided in the standard (σyr=780MPa) and the corresponding depth as the ratio of the head hardened zone along the axis of symmetry are as follows: (1.17 σyr, 20%), (1.06 σyr, 20%- 80%) and (0.71 σyr, > 80%). The stress-strain curves exhibit limited plastic zone with fracture occurring at strain less than 0.1.

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A road bridge containing disused flatbed rail wagons as the primary deck superstructure was performance tested in a low volume, high axle load traffic road in Queensland, Australia; some key results are presented in this paper. A fully laden truck of total weight 28.88 % of the serviceability design load prescribed in the Australian bridge code was used; its wheel positions were accurately captured using a high speed camera and synchronised with the real‐time deflections and strains measured at the critical members of the flat rail wagons. The strains remained well below the yield and narrated the existence of composite action between the reinforced concrete slab pavement and the wagon deck. A three dimensional grillage model was developed and calibrated using the test data, which established the structural adequacy of the rail wagons and the positive contribution of the reinforced concrete slab pavement to resist high axle traffic loads on a single lane bridge in the low volume roads network.

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Service-oriented Architectures (SOA) and Web services leverage the technical value of solutions in the areas of distributed systems and cross-enterprise integration. The emergence of Internet marketplaces for business services is driving the need to describe services, not only from a technical level, but also from a business and operational perspective. While, SOA and Web services reside in an IT layer, organizations owing Internet marketplaces are requiring advertising and trading business services which reside in a business layer. As a result, the gap between business and IT needs to be closed. This paper presents USDL (Unified Service Description Language), a specification language to describe services from a business, operational and technical perspective. USDL plays a major role in the Internet of Services to describe tradable services which are advertised in electronic marketplaces. The language has been tested using two service marketplaces as use cases.

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A key issue in the economic development and performance of organizations is the existence of standards. Their definition and control are sources of power and it is important to understand their concept, as it gives standards their direction and their legitimacy, and to explore how they are represented and applied. The difficulties posed by classical micro-economics in establishing a theory of standardization that is compatible with its fundamental axiomatic are acknowledged. We propose to reconsider the problem by taking the opposite perspective in questioning its theoretical base and by reformulating assumptions about the independent and autonomous decisions taken by actors. The Theory of Conventions will offer us a theoretical framework and tools enabling us to understand the systemic dimension and dynamic structure of standards. These will be seen as a special case of conventions. This work aims to provide a sound basis and promote a better consciousness in the development of global project management standards. It aims also to emphasize that social construction is not a matter of copyright but a matter of open minds, collective cognitive process and freedom for the common wealth.

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A key issue for the economic development and for performance of organizations is the existence of standards. As their definitions and control are source of power, it seems to be important to understand the concept and to wonder about the representations authorized by the concept which give their direction and their legitimacy. The difficulties of classical microeconomics of establishing a theory of standardisation compatible with its fundamental axiomatic are underlined. We propose to reconsider the problem by carrying out the opposite way: to question the theoretical base, by reformulating assumptions on the autonomy of the choice of the actors. The theory of conventions will offer us both a theoretical framework and tools, enabling us to understand the systemic dimension and dynamic structure of standards seen as special case of conventions. This work aims thus to provide a sound basis and promote a better consciousness in the development of global project management standards, aiming also to underline that social construction is not a matter of copyright but a matter of open minds, collective cognitive process and freedom for the common wealth.

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In this paper, we report on many phosphate containing natural minerals found in the Jenolan Caves - Australia. Such minerals are formed by the reaction of bat guano and clays from the caves. Among these cave minerals is the montgomeryite mineral [Ca4MgAl4(PO4)6.(OH)4.12H2O]. The presence of montgomeryite in deposits of the Jenolan Caves - Australia has been identified by X-ray diffraction (XRD). Raman spectroscopy complimented with infrared spectroscopy has been used to characterize the crystal structure of montgomeryite. The Raman spectrum of a standard montgomeryite mineral is identical to that of the Jenolan Caves sample. Bands are assigned to H2PO4-, OH and NH stretching vibrations. By using a combination of XRD and Raman spectroscopy, the existence of montgomeryite in the Jenolan Caves - Australia has been proven. A mechanism for the formation of montgomeryite is proposed.

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Public participate in the planning and design of major public infrastructure and construction (PIC) projects is crucial to their success, as the interests of different stakeholders can be systematically captured and built into the finalised scheme. However, public participation may not always yield a mutually acceptable solution, especially when the interests of stakeholders are diverse and conflicting. Confrontations and disputes can arise unless the concerns or needs of the community are carefully analysed and addressed. The aim of the paper is to propose a systematic method of analysing stakeholder concerns relating to PIC projects by examining the degree of consensus and/or conflict involved. The results of a questionnaire survey and a series of interviews with different entities are provided, which indicate the existence of a significant divergence of views among stakeholder groups and that conflicts arise when there is a mismatch between peoples’ perception concerning money and happiness on the one hand and development and damages on the other. Policy and decision-makers should strive to resolve at least the majority of conflicts that arise throughout the lifecycle of major PIC projects so as to maximise their chance of success.

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Solids are widely identified as a carrier of harmful pollutants in stormwater runoff exerting a significant risk to receiving waters. This paper outlines the findings of an in-depth investigation on heavy metal adsorption to solids surfaces. Pollutant build-up samples collected from sixteen road sites in residential, industrial and commercial land uses were separated into four particle size ranges and analysed for a range of physico-chemical parameters and nine heavy metals including Iron (Fe), Aluminum (Al), Lead (Pb), Zinc (Zn), Cadmium (Cd), Chromium (Cr), Manganese (Mn), Nickel (Ni) and Copper (Cu). High specific surface area (SSA) and total organic carbon (TOC) content in finer particle size ranges was noted, thus confirming strong correlations with heavy metals. Based on their physico-chemical characteristics, two different types of solids originating from traffic and soil sources were identified. Solids generated by traffic were associated with high loads of heavy metals such as Cd and Cr with strong correlation with SSA. This suggested the existence of surface dependent bonds such as cation exchange between heavy metals and solids. In contrast, Fe, Al and Mn which can be attributed to soil inputs showed strong correlation with TOC suggesting strong bonds such as chemsorption. Zn was found to be primarily attached to solids by bonding with the oxides of Fe, Al and Mn. The data analysis also confirmed the predominance of the finer fraction, with 70% of the solids being finer than 150 µm and containing 60% of the heavy metal pollutant load.

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In light of McDermott Industries (AUST) Pty Ltd v Commissioner of Taxation, and Draft Taxation Ruling TR 2006/D8, this article considers the current Australian taxation position of profits arising from the cross-border leasing of vessels in the maritime industry. It focuses on the tax treaties to which Australia is a party, in particular the application of the business profits provisions of those treaties, and the deemed existence of a permanent establishment where substantial equipment, owned by a fiscal non-resident, is used within Australian waters.