139 research outputs found

    A Comparison of Critical Infrastructure Resilience Quantification Techniques

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    Promoting the resilience of critical infrastructure, when subjected to different hazardous events, is vital. However, applying inappropriate and/or imprecise resilience metrics or quantification techniques could increase the costs of resilience enhancement and reduce its effectiveness in critical infrastructure. This paper develops a method to evaluate and compare different resilience quantification techniques, in relation to different system failure states, in order to measure their effectiveness

    City sustainability: the influence of walkability on built environments

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    A vital issue in community is providing an easy access to the transport network for different range of community members such as; very young, old, children and disable people. The functions that walking and walkable area can be support includes community involvement, health, meeting and gathering and recreation which has positive effects on sustainability and vice versa. Walkability is the basis of sustainable city. The same as bicycling, walking can be known as ‘green’ type of transportation which except crowding reduction and also has low level of environmental influence, energy conserving without any air and noise pollution. It can be more than a purely useful type of travel to shopping, school and work. Also have both social and recreational importance. This research aims at supporting urban design knowledge and practice and contributing to the broader field of “walkability” by refining the methods and measures used to analyse the relationship between walking behaviour and physical environment and its impacts on city sustainability. In order to integrate knowledge from theories and research on walkability from different fields and of different perspectives, it is crucial to first build a broader view and a more comprehensive understanding of how the built environment influences walking. What has been done during the earlier part of this project, and will be shown in this research, is to provide a better understanding of the complexity of the relationship between the built environment and walking and also the complexity that lies in both of these entities, the urban form and walking activity

    Modelling the Performance of an Integrated Urban Wastewater System under Future Conditions

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    This PhD thesis was awarded by the Exeter Research Scholarship (ERS).The performance of the Integrated Urban Wastewater Systems (IUWS) including: sewer system, WWTP and river, in both operational control and design, under unavoidable future climate change and urbanisation is a concern for water engineers which still needs to be improved. Additionally, with regard to the recent attention around the world to the environment, the quality of water, as the main component of that, has received significant attention as it can have impacts on health of human life, aquatic life and so on. Hence, the necessity of improving systems performance under the future changes to maintain the quality of water is observed. The research presented in this thesis describes the development of risk-based and non-risk-based models to improve the operational control and design of the IUWS under future climate change and urbanisation aiming to maintain the quality of water in recipients. In this thesis, impacts of climate change and urbanisation on the IUWS performance in terms of the receiving water quality was investigated. In the line with this, different indicators of climate change and urbanisation were selected for evaluation. Also the performance of the IUWS under future climate change and urbanisation was improved by development of a novel non-risk-based operational control and design models aiming to maintain the quality of water in the river to meet the water quality standards in the recipient. This is initiated by applying a scenario-based approach to describe the possible features of future climate change and /or urbanisation. Additionally the performance of the IUWS under future climate change and urbanisation was improved by development of a novel risk-based operational control and design models to reduce the risk of water quality failures to maintain the health of aquatic life. This is initiated by considering the uncertainties involved with the urbanisation parameters considered. The risk concept is applied to estimate the risk of water quality breaches for the aquatic life. Also due to the complexity and time-demanding nature of the IUWS simulation models (which are called about the optimisation process), there is the concern about excessive running times in this study. The novel “MOGA-ANNβ” algorithm was developed for the optimisation process throughout the thesis to speed it up while preserving the accuracy. The meta-model developed was tested and its performance was evaluated. In this study, the results obtained from the impact analysis of the future climate change and urbanisation (on the performance of the IUWS) showed that the future conditions have potential to influence the performance of the IUWS in both quality and quantity of water. In line with this, selecting proper future conditions’ parameters is important for the system impact analysis. Also the observations demonstrated that the system improvement is required under future conditions. In line with this, the results showed that both risk-based and non-risk-based operational control optimisation of the IUWS in isolation is not good enough to cope with the future conditions and therefore the IUWS design optimisation was carried out to improve the system performance. The riskbased design improvement of the IUWS in this study showed a better potential than the non-risk-based design improvement to meet all the water quality criteria considered in this study

    Feature reduction of hyperspectral images: Discriminant analysis and the first principal component

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    When the number of training samples is limited, feature reduction plays an important role in classification of hyperspectral images. In this paper, we propose a supervised feature extraction method based on discriminant analysis (DA) which uses the first principal component (PC1) to weight the scatter matrices. The proposed method, called DA-PC1, copes with the small sample size problem and has not the limitation of linear discriminant analysis (LDA) in the number of extracted features. In DA-PC1, the dominant structure of distribution is preserved by PC1 and the class separability is increased by DA. The experimental results show the good performance of DA-PC1 compared to some state-of-the-art feature extraction methods

    Malnutrition and medical nutrition therapy in hospitalized children: a case study of using national malnutrition screening tools in northeastern Iran

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    Background: Nationwide studies have focused only on prevalence of malnutrition in hospitalized children, while medical nu- trition therapies and assessing nutritional interventions is neglected.Methods: This research was conducted in tertiary level children hospitals in the NorthEastern region of Iran for 1 year from 2016 to 2017. Five questions were included in the initial assessment form and, if there was even one positive response, nutrition- al interventions were prescribed for the patients.Results: A total of 65 children aged ≥ 5 years and hospitalized for ≥ two days were included. 24.6% of patients had 2 >BMI Z-score>-2 at time of admission. At the beginning of the study, weight loss more than 10%, and appetite loss or decreased food intake was observed in 10.8% and 20% of the study population, respectively. Median BMI percentile of patients with nutritional intervention was 8.9 (0.1-98.7) at the beginning of the study and 12.7 (0.1-98.4) at discharge time which shows a significant difference (P=0.01).Conclusion: Medical nutrition therapy employed in this study prevented deterioration of nutritional status of children during hospitalization and was effective in stabilizing indices of nutritional status.Keywords: Body mass index, hospitalized children, malnutrition

    The role of central oxytocin in stress-induced cardioprotection in ischemic-reperfused heart model

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    Background and purpose: There is growing evidence that stress contributes to cardiovascular disease and triggers the release of oxytocin. Moreover previous studies confirmed oxytocin mimics the protection associated with ischemic preconditioning. The present study was aimed to assess the possible cardioprotective effects of the centrally released oxytocin in response to stress and intracerebroventricular (i.c.v.) administration of exogenous oxytocin in ischemic-reperfused isolated rat heart. Methods and subjects: Rats were divided in two main groups and all of them were subjected to i.c.v. infusion of vehicle or drugs: unstressed rats control: vehicle, oxytocin (OT; 100 ng/5 mu l), atosiban (ATO; 4.3 mu g/5 mu l) as oxytocin antagonist, ATO + OT] and stressed rats St: stress, OT + St, ATO + St]. After anesthesia, hearts were isolated and subjected to 30 min regional ischemia and 60 min reperfusion (IR). Acute stress protocol included swimming for 10 min before anesthesia. Myocardial function, infarct size, coronary flow, ventricular arrhythmia, and biochemical parameters such as creatine kinase and lactate dehydrogenase were measured. Ischemia-induced ventricular arrhythmias were counted during the occlusion period. Results: The plasma levels of oxytocin and corticosterone were significantly elevated by stress. Unexpectedly hearts of stressed rats showed a marked depression of IR injury compared to control group. I.c.v. infusion of oxytocin mimicked the cardioprotective effects of stress, yet did not elevate plasma oxytocin level. The protective effects of both stress and i.c.v. oxytocin were blocked by i.c.v. oxytocin antagonist. Conclusions: These findings suggest that i.c.v. infusion of exogenous oxytocin and centrally released endogenous oxytocin in response to stress could play a role in induction of a preconditioning effect in ischemic-reperfused rat heart via brain receptors. (C) 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved

    Design and operation of urban wastewater systems considering reliability, risk and resilience

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    Reliability, risk and resilience are strongly related concepts and have been widely utilised in the context of water infrastructure performance analysis. However, there are many ways in which each measure can be formulated (depending on the reliability of what, risk to what from what, and resilience of what to what) and the relationships will differ depending on the formulations used. This research has developed a framework to explore the ways in which reliability, risk and resilience may be formulated, identifying possible components and knowledge required for calculation of each and formalising the conceptual relationships between specified and general resilience. This utilises the Safe & SuRe framework, which shows how threats to a water system can result in consequences for society, the economy and the environment, to enable the formulations to be derived in a logical manner and to ensure consistency in any comparisons. The framework is used to investigate the relationship between levels of reliability, risk and resilience provided by multiple operational control and design strategies for an urban wastewater system case study. The results highlight that, although reliability, risk and resilience values may exhibit correlations, designing for just one is insufficient: reliability, risk and resilience are complementary rather than interchangeable measures and one cannot be used as a substitute for another. Furthermore, it is shown that commonly used formulations address only a small fraction of the possibilities and a more comprehensive assessment of a system’s response to threats is necessary to provide a comprehensive understanding of risk and resilience

    Enhanced Residential Bathroom Sustainability: Challenges and Opportunities

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    The research reviews the rationale behind water and energy saving in the domestic application within the bathroom unit in the UK. Various technologies for water saving including rainwater harvesting and greywater recycling and the related regulatory issues are reviewed. Various water saving toilets, as well as waste water heat recovery systems, were discussed and compared. The incentives, impact, challenges, and opportunities for various stakeholders including end user, property developers, technology companies and researchers, utility companies and the government are analysed. The review shows that greywater recycling for toilet flushing has highest user acceptance and is inevitable for zero/close to zero carbon home development. It was found that technology barriers are still an important factor in the application of the current products, including adaptability and size to fit a wide range of bathrooms as well as initial cost. The retrofitability of any technology was found important to create a timely impact on the decline of resources and infrastructure stress. The article gathers a range of technological and market challenges based on the individual components and technologies in the bathroom and concludes that an integrated approach is required for an effective technology in the bathroom

    Effects of Probiotic Cells on the Mechanical and Antibacterial Properties of Sodium-Caseinate Films

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    Background and Objective: Food processing conditions such as heat, mechanical or osmotic stress can lead to considerable losses of probiotics’ survival in food. Recently, the addition of probiotics into edible films has been proposed as an emerging technology for the delivery of probiotic cells. In this study, Lactobacillus acidophilus and Lactobacillus casei cells were incorporated into sodium caseinate matrix to develop a probiotic-based film which can improve food safety.Material and Methods: Probiotic cells were separately added to the film forming solutions and the active films were prepared by casting method. The physical, optical and mechanical characteristics of the films were examined. Color properties were determined using a colorimeter and the mechanical properties of the films were evaluated by an Instron Universal Testing Machine. The viability of Lactobacillus acidophilus and Lactobacillus casei in the films was determined during a period of 12 days. The antibacterial activities of the films were also tested against Listeria monocytogenes on Trypticase Soy Agar medium at 4°C.Results and Conclusion: Results demonstrated that lactic acid bacteria cells remained viable during a storage period of 12 days (> 4 Log CFU cm-2). The incorporation of lactic acid bacteria cells into the film polymer had no significant effect on tensile strength (p>0.05) whereas it significantly improves the appearance of films. Indeed, samples covered with the lactic acid bacteria film displayed higher anti-listerial activity than the control group on day 6 of preservation (p≤0.05). These findings show that the sodium caseinate film containing lactic acid bacteria cells can be used as a new effective packaging method for improving food safety
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