30,006 research outputs found

    The Glasgow sustainable urban drainage system management project: Case studies (Belvidere hospital and Celtic FC stadium areas)

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    The Glasgow Sustainable Urban Drainage System (SUDS) Management Project satisfies the first phase of the Glasgow Surface Water Management Project. This is Glasgow City Council’s contribution to the Transformation of Rural and Urban Spatial Structure (TRUST) project, one of the European Union’s (EU) interregional (INTERREG IIIB) funded research projects. The remit of this EU project comprises also other representative regions in Europe. The project shows also how SUDS can contribute to the overall catchment dynamics of cities such as Glasgow, ultimately relieving stress on the current predominantly combined sewer system. Fifty-seven sites within 46 areas of Glasgow were identified for investigation. A detailed soil chemistry analysis, a preliminary SUDS feasibility assessment and a desk study relating to historical planning issues that may be relevant for subsequent future development and regeneration options were undertaken. Detailed design and management guidelines were then drafted for selected representative demonstration areas (Belvidere Hospital and Celtic FC Stadium Areas) of high public and property developers interest, and education value. A combination of infiltration trenches or swales with ponds or underground storage were the most likely SUDS options for the majority of the demonstration areas. Soil contamination issues were considered when selecting SUDS because heavy metals such as lead and zinc can cause environmental health problems

    The Glasgow sustainable urban drainage system management project: Case studies (Belvidere hospital and Celtic FC stadium areas)

    Get PDF
    The Glasgow Sustainable Urban Drainage System (SUDS) Management Project satisfies the first phase of the Glasgow Surface Water Management Project. This is Glasgow City Council’s contribution to the Transformation of Rural and Urban Spatial Structure (TRUST) project, one of the European Union’s (EU) interregional (INTERREG IIIB) funded research projects. The remit of this EU project comprises also other representative regions in Europe. The project shows also how SUDS can contribute to the overall catchment dynamics of cities such as Glasgow, ultimately relieving stress on the current predominantly combined sewer system. Fifty-seven sites within 46 areas of Glasgow were identified for investigation. A detailed soil chemistry analysis, a preliminary SUDS feasibility assessment and a desk study relating to historical planning issues that may be relevant for subsequent future development and regeneration options were undertaken. Detailed design and management guidelines were then drafted for selected representative demonstration areas (Belvidere Hospital and Celtic FC Stadium Areas) of high public and property developers interest, and education value. A combination of infiltration trenches or swales with ponds or underground storage were the most likely SUDS options for the majority of the demonstration areas. Soil contamination issues were considered when selecting SUDS because heavy metals such as lead and zinc can cause environmental health problems

    Long-Distance Trust-Free Quantum Key Distribution

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    The feasibility of trust-free long-haul quantum key distribution (QKD) is addressed. We combine measurement-device-independent QKD (MDI-QKD), as an access technology, with a quantum repeater setup, at the core of future quantum communication networks. This will provide a quantum link none of whose intermediary nodes need to be trusted, or, in our terminology, a trust-free QKD link. As the main figure of merit, we calculate the secret key generation rate when a particular probabilistic quantum repeater protocol is in use. We assume the users are equipped with imperfect single photon sources, which can possibly emit two single photons, or laser sources to implement decoy-state techniques. We consider apparatus imperfection, such as quantum efficiency and dark count of photodetectors, path loss of the channel, and writing and reading efficiencies of quantum memories. By optimizing different system parameters, we estimate the maximum distance over which users can share secret keys when a finite number of memories are employed in the repeater setup

    Familial strife on the seashore: aggression increases with relatedness in the sea anemone Actinia equina.

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    Pairwise contests occur when two individuals compete directly over ownership of an indivisible resource. Contests vary in the degree of escalation, some encounters being settled through non-injurious behaviour while others are only resolved after dangerous fighting. Here, we investigate the role of relatedness, assessed using AFLP analysis, on the occurrence of stinging during staged contests in the beadlet sea anemone Actinia equina. Contrary to our expectations, we found that the chance of stinging, and hence the chance of inflicting damage, increased with the degree of relatedness between the two opponents. This result may be explained by the negative relationship between asymmetry in fighting ability and escalation level predicted by theory. We suggest that in order to fully understand how relatedness influences aggression, predictions from kin selection theory should be incorporated with those from contest theory

    Measurement-device-independent quantum key distribution with ensemble-based memories

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    Quantum memories are enabling devices for extending the reach of quantum key distribution (QKD) systems. The required specifications for memories are, however, often considered too demanding for available technologies. One can change this mindset by introducing memory-assisted measurement-device-independent QKD (MDI-QKD), which imposes less stringent conditions on the memory modules. It has been shown that, in the case of fast single-qubit memories, we can reach rates and distances not attainable by single no-memory QKD links. Single-qubit memories, such as single atoms or ions, have, currently, too slow of an access time to offer an advantage in practice. Here, we relax that assumption, and consider ensemble-based memories, which satisfy the main two requirements of having short access times and large storage-bandwidth products. Our results, however, suggest that the multiple-excitation effects in such memories can be so detrimental that they may wash away the scaling improvement offered by memory-equipped systems. We then propose an alternative setup that can in principle remedy the above problem. As a prelude to our main problem, we also obtain secret key generation rates for MDI-QKD systems that rely on imperfect single-photon sources with nonzero probabilities of emitting two photons

    Genetic and Environmental Contributions to Body Mass Index: Comparative Analysis of Monozygotic Twins, Dizygotic Twins and Same-Age Unrelated Siblings

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    Background—Earlier studies have established that a substantial percentage of variance in obesity-related phenotypes is explained by genetic components. However, only one study has used both virtual twins (VTs) and biological twins and was able to simultaneously estimate additive genetic, non-additive genetic, shared environmental and unshared environmental components in body mass index (BMI). Our current goal was to re-estimate four components of variance in BMI, applying a more rigorous model to biological and virtual multiples with additional data. Virtual multiples share the same family environment, offering unique opportunities to estimate common environmental influence on phenotypes that cannot be separated from the non-additive genetic component using only biological multiples. Methods—Data included 929 individuals from 164 monozygotic twin pairs, 156 dizygotic twin pairs, five triplet sets, one quadruplet set, 128 VT pairs, two virtual triplet sets and two virtual quadruplet sets. Virtual multiples consist of one biological child (or twins or triplets) plus one same-aged adoptee who are all raised together since infancy. We estimated the additive genetic, non-additive genetic, shared environmental and unshared random components in BMI using a linear mixed model. The analysis was adjusted for age, age2, age3, height, height2, height3, gender and race. Results—Both non-additive genetic and common environmental contributions were significant in our model (P-values \u3c 0.0001). No significant additive genetic contribution was found. In all, 63.6% (95% confidence interval (CI) 51.8–75.3%) of the total variance of BMI was explained by a non-additive genetic component, 25.7% (95% CI 13.8–37.5%) by a common environmental component and the remaining 10.7% by an unshared component. Conclusion—Our results suggest that genetic components play an essential role in BMI and that common environmental factors such as diet or exercise also affect BMI. This conclusion is consistent with our earlier study using a smaller sample and shows the utility of virtual multiples for separating non-additive genetic variance from common environmental variance

    What factors determine the use of the nutrition information on the food label when female consumers from Pietermaritzburg select and purchase fat spreads?

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    Objectives: This study set out to determine the following in relation to the nutrition information on the food labels of selected fat spreads: the demographic profile of female consumers using the food label, reasons for food label use and whether the use of the food label leads to the purchase of the selected fat spreads.Methods: One hundred and fifty women aged 25 to 45 years were chosen using an accidental, non-probability sample of consumers shopping at selected supermarkets in Pietermaritzburg. Consenting subjects were presented with a questionnaire to determine their demographic characteristics as well as their reasons for purchasing the selected fat spreads. Descriptive statistics and principal component analyses were used to analyse the results of this study.Results: Fifty-five per cent (n = 82) of this study sample reported using the nutrition information label to assist with their purchases and 68% (n = 102) found the nutrition information important when purchasing a new product.Conclusions: The female consumer most likely to use the nutrition  information on the food label had a tertiary education; was a primary food purchaser; lived with other people; had more money per month to spend on food; and was conscious of choosing the healthier option. Principal component analysis revealed that the purchase of a selected fat spread was influenced by a number of variables reflecting health awareness, the selected fat spread’s marketing, presentation and popularity, and familiarity with and cost awareness of the selected fat spread

    Prediction of flowability of cohesive powder mixtures at high strain rate conditions by discrete element method

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    Flow behaviour of powders plays an important role in defining their performance in many industries. In this study, we present our work on prediction of flow characteristics of binary and ternary mixtures under dynamic conditions using Discrete Element Method and simulating the expended mechanical work of a rotating impeller penetrating a packed bed. Three commonly used methods for calculating a mean have been explored to express the mixture Bond number, namely arithmetic, geometric and harmonic mean. This is done by introducing a weighting factor based on the fractional surface area of each component of the mixture. The mixture Bond number is dependent on the interfacial surface energy, particle size and density; and a wide range of Bond number is covered in our study by varying all three. The expended work of impeller shows the clearest trend with the mixture Bond number when it is expressed in terms of the arithmetic mean. Although we only used binary and ternary mixtures (40 different mixtures in total) in this study, the trend should be applicable to multi-component mixtures and therefore useful as a design aide for powder formulation
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