998 resultados para radiation trends


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In this introductory chapter to Schmeinck, D. and Lidstone, J. (2014) “Current trends and issues in geographical education” in Schmeinck, D. and Lidstone, J. (2014) Eds) Standards and Research in Geographical Education: Current Trends and International Issues. Berlin. Mensch und Buch Verlag. Pp. 5 - 16. , the authors review and analyse eleven papers originally presented to the Congress of the International Geographical Union held in Cologne in 2012. Taking the collection of papers as a single corpus representing the “state of the art” of geography education, they applied lexical and bibliometric analyses in an innovative attempt to identify the nature of geographical education as represented by this anthology of peer reviewed chapters presented at the start of the second decade of the Twenty-first century?

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What is the state of geographical education in the second decade of the 21st century? This volume presents a selection of peer reviewed papers presented at the 2012 Cologne Congress of the International Geographical Union (IGU) sessions on Geographical Education as representative of current thinking in the area. It then presents (perhaps for the first time) a cross-case analysis of the common factors of all these papers as a current summary of the “state of the art” of geographical education today. The primary aim of the individual authors as well as the editors is not only to record the current state of the art of geographical education but also to promote ongoing discussions of the longer term health and future prospects of international geographical education. We wish to encourage ongoing debate and discussion amongst local, national, regional and international education journals, conferences and discussion groups as part of the international mission of the Commission on Geographical Eduction. While the currency of these chapters in terms of their foci, breadth and recency of the theoretical literature on which they are based and the new research findings they present justifies considerable confidence in the current health of geographical education as an educational and research endeavour, each new publication should only be the start of new scholarly inquiry. Where should we, as a scholarly community, place our energies for the future? If readers are left with a new sense of direction, then the aims of the authors and editors will have been amply met.

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Persistent organic pollutants (POPs) such as dioxins, PCBs, persistent organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) as well as perfluorinated compounds (PFCs) and triclosan are ubiquitous in the human population. In Australia, we have pooled and subsequently analysed over 10 000 human serum samples for the determination of these chemicals by age group (0–0.5; 0.6–1; 1.1–1.5; 1.6–2; 2.1–2.5; 2.6–3; 3.1–3.5; 3.6–4; 4.1–6; 6.1–9; 9.1–12; 12.1–15; 16–30; 31–45; 46–60 and >60 years) and gender. The results of this analysis were then used to assess the trends of these different chemicals as a function of age, gender and to a lesser extent region. Our data demonstrate clear chemical specific age trends. In particular we demonstrate that for the traditional POPs there is an increase in body burden with age whereas the opposite is true for chemicals such as PBDEs. For PFCs we find chemical specific age trends that vary from compound to compound. For triclosan we show that no apparent age trend is observable. The results of the study and its implications to the collection and archiving of samples for retrospective analysis are discussed.

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This book underlines the growing importance of knowledge for the competitiveness of cities and their regions. Examining the role of knowledge - in its economic, socio-cultural, spatial and institutional forms - for urban and regional development, identifying the preconditions for innovative use of urban and regional knowledge assets and resources, and developing new methods to evaluate the performance and potential of knowledge-based urban and regional development, the book provides an in-depth and comprehensive understanding of both theoretical and practical aspects of knowledge-based development and its implications and prospects for cities and regions.

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Providing mobility corridors for communities, enabling freight networks to transport goods and services, and a pathway for emergency services and disaster relief operations, roads are a vital component of our societal system. In the coming decades, a number of modern issues will face road agencies as a result of climate change, resource scarcity and energy related challenges that will have implications for society. To date, these issues have been discussed on a case by case basis, leading to a fragmented approach by state and federal agencies in considering the future of roads – with potentially significant cost and risk implications. Within this context, this paper summarises part of a research project undertaken within the ‘Greening the Built Environment’ program of the Sustainable Built Environment National Research Centre (SBEnrc, Australia), which identified key factors or ‘trends’ affecting the future of roads and key strategies to ensure that road agencies can continue to deliver road infrastructure that meets societal needs in an environmentally appropriate manner. The research was conducted over two years, including a review of academic and state agency literature, four stakeholder workshops in Western Australia and Queensland, and industry consultation. The project was supported financially and through peer review and contribution, by Main Roads Western Australia, QLD Department of Transport and Main Roads, Parsons Brinckerhoff, John Holland Group, and the Australian Green Infrastructure Council (AGIC). The project highlighted several potential trends that are expected to affect road agencies in the future, including predicted resource and materials shortages, increases in energy and natural resources prices, increased costs related to greenhouse gas emissions, changing use and expectations of roads, and changes in the frequency and intensity of weather events. Exploring the implications of these potential futures, the study then developed a number of strategies in order to prepare transport agencies for the associated risks that such trends may present. An unintended outcome of the project was the development of a process for enquiring into future scenarios, which will be explored further in Stage 2 of the project (2013-2014). The study concluded that regardless of the type and scale of response by the agency, strategies must be holistic in approach, and remain dynamic and flexible.

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This article describes a Matlab toolbox for parametric identification of fluid-memory models associated with the radiation forces ships and offshore structures. Radiation forces are a key component of force-to-motion models used in simulators, motion control designs, and also for initial performance evaluation of wave-energy converters. The software described provides tools for preparing non-parmatric data and for identification with automatic model-order detection. The identification problem is considered in the frequency domain.

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This contribution outlines Synchrotron-based X-ray micro-tomography and its potential use in structural geology and rock mechanics. The paper complements several recent reviews of X-ray microtomography. We summarize the general approach to data acquisition, post-processing as well as analysis and thereby aim to provide an entry point for the interested reader. The paper includes tables listing relevant beamlines, a list of all available imaging techniques, and available free and commercial software packages for data visualization and quantification. We highlight potential applications in a review of relevant literature including time-resolved experiments and digital rock physics. The paper concludes with a report on ongoing developments and upgrades at synchrotron facilities to frame the future possibilities for imaging sub-second processes in centimetre-sized samples.

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The dynamics describing the motion response of a marine structure in waves can be represented within a linear framework by the Cummins Equation. This equation contains a convolution term that represents the component of the radiation forces associated with fluid memory effects. Several methods have been proposed in the literature for the identification of parametric models to approximate and replace this convolution term. This replacement can facilitate the model implementation in simulators and the analysis of motion control designs. Some of the reported identification methods consider the problem in the time domain while other methods consider the problem in the frequency domain. This paper compares the application of these identification methods. The comparison is based not only on the quality of the estimated models, but also on the ease of implementation, ease of use, and the flexibility of the identification method to incorporate prior information related to the model being identified. To illustrate the main points arising from the comparison, a particular example based on the coupled vertical motion of a modern containership vessel is presented.

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"Combining facets of health physics with medicine, An Introduction to Radiation Protection in Medicine covers the background of the subject and the medical situations where radiation is the tool to diagnose or treat human disease. Encouraging newcomers to the field to properly and efficiently function in a versatile and evolving work setting, it familiarizes them with the particular problems faced during the application of ionizing radiation in medicine. The text builds a fundamental knowledge base before providing practical descriptions of radiation safety in medicine. It covers basic issues related to radiation protection, including the physical science behind radiation protection and the radiobiological basis of radiation protection. The text also presents operational and managerial tools for organizing radiation safety in a medical workplace. Subsequent chapters form the core of the book, focusing on the practice of radiation protection in different medical disciplines. They explore a range of individual uses of ionizing radiation in various branches of medicine, including radiology, nuclear medicine, external beam radiotherapy, and brachytherapy. With contributions from experienced practicing physicists, this book provides essential information about dealing with radiation safety in the rapidly shifting and diverse environment of medicine."--publisher website

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The effect of radiation on natural convection of Newtonian fluid contained in an open cavity is investigated in this study. The governing partial differential equations are solved numerically using the Alternate Direct Implicit method together with the Successive Over Relaxation method. The study is focused on studying the flow pattern and the convective and radiative heat transfer rates are studied for different values of radiation parameters namely, the optical thickness of the fluid, scattering albedo, and the Planck number. It was found that in the optically thin limit, an increase in the optical thickness of the fluid raises the temperature and radiation heat transfer of the fluid. However, a further increase in the optical thickness decreases the radiative heat transfer rate due to increase in the energy level of the fluid, which ultimately reduces the total heat transfer rate within the fluid.

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Purpose To investigate the effects of a natural oil-based emulsion containing allantoin versus aqueous cream for preventing and managing radiation induced skin reactions (RISR). Methods and Materials A total of 174 patients were randomised and participated in the study. Patients either received Cream 1 (the natural oil-based emulsion containing allantoin) or Cream 2 (aqueous cream). Skin toxicity, pain, itching and skin-related quality of life scores were collected for up to four weeks after radiation treatment. Results Patients who received Cream 1 had a significantly lower average level of Common Toxicity Criteria at week 3 (p<0.05), but had statistically higher average levels of skin toxicity at weeks 7, 8 and 9 (all p<0.001). Similar results were observed when skin toxicity was analysed by grades. With regards to pain, patients in the Cream 2 group had a significantly higher average level of worst pain (p<0.05) and itching (p=0.046) compared to the Cream 1 group at week 3, however these differences were not observed at other weeks. In addition, there was a strong trend for Cream 2 to reduce the incidence of grade 2 or more skin toxicity in comparison to Cream 1 (p=0.056). Overall, more participants in the Cream 1 group were required to use another topical treatment at weeks 8 (p=0.049) and 9 (p=0.01). Conclusion The natural oil-based emulsion containing allantoin appears to have similar effects for managing skin toxicity compared to aqueous cream up to week 5, however, it becomes significantly less effective at later weeks into the radiation treatment and beyond treatment completion (week 6 and beyond). There were no major differences in pain, itching and skin-related quality of life. In light of these results, clinicians and patients can base their decision on costs and preferences. Overall, aqueous cream appears to be a more preferred option.

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As the end of the Cold War approached in 1989, Caroline Thomas argued: “It is important that the discipline [International Relations, IR] should address the issue of disease and more broadly, health, not simply to facilitate containment of disease transmission across international borders but also because central notions of justice, equity, efficiency and order are involved” (1989:273).1 Ten years later, Craig Murphy echoed these sentiments. Murphy (2001: 352) proposed that IR had yet to grapple with the political consequences of growing inequality between the world’s rich and poor, and areas such as health—where these inequalities were most stark—should become the field’s core business. How IR’s theories and methods would approach these issues was less clear. Bettcher and Yach (1998) cautioned that IR would be unable to develop progressive research projects that explored global health diplomacy as a global public good without adopting new perspectives and methods. Others warned that the expansion of security studies into areas such as global health would weaken the intellectual coherency of the field (Walt 1991:213). Taking its cue from the recent Ng and Prah Ruger (2011) study, this paper returns to these concerns to briefly explore key trends and potential future concerns of research in IR on health...

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Radiosensitizing Effect of Electrochemotherapy in a Fractionated Radiation Regimen in Radiosensitive Murine Sarcoma and Radioresistant Adenocarcinoma Tumor Model. Electrochemotherapy can potentiate the radiosensitizing effect of bleomycin, as shown in our previous studies. To bring this treatment closer to use in clinical practice, we evaluated the interaction between electrochemotherapy with bleomycin and single-dose or fractionated radiation in two murine tumor models with different histology and radiosensitivity. Radiosensitive sarcoma SA-1 and radioresistant adenocarcinoma CaNT subcutaneous tumors grown in A/J and CBA mice, respectively, were used. The anti-tumor effect and skin damage around the treated tumors were evaluated after electrochemotherapy with bleomycin alone or combined with single-dose radiation or a fractionated radiation regimen. The anti-tumor effectiveness of electrochemotherapy was more pronounced in SA-1 than CaNT tumors. In both tumor models, the tumor response to radiation was not significantly influenced by bleomycin alone or by electroporation alone. However, electrochemotherapy before the first tumor irradiation potentiated the response to a single-dose or fractionated radiation regimen in both tumors. For the fractionated radiation regimen, normal skin around the treated tumors was damaged fourfold less than for the single-dose regimen. Electrochemotherapy prior to single-dose irradiation induced more damage to the skin around the treated tumors and greater loss of body weight compared to other irradiated groups, whereas electrochemotherapy combined with the fractionated radiation regimen did not. Electrochemotherapy with low doses of bleomycin can also be used safely for radiosensitization of different types of tumors in a fractionated radiation regimen, resulting in a good anti-tumor effect and no major potentiating effect on radiation-induced skin damage. © 2009 by Radiation Research Society.