241 research outputs found

    Full-Scale Shaking Table Tests on Deficient Rc Buildings Strengthened With FRP Composites

    Get PDF
    The paper discusses the results from experimental programmes including full-scale shaking table tests on two deficient one-span two-storey RC frame buildings strengthened with Carbon Fibre Reinforced Polymer (CFRP) composites. The tests were performed at one of the world class shaking table testing facility, the AZALEE shake table at the Commissariat à l’Énergie Atomique (CEA), Laboratory in Saclay, France, as part of two European (EU) funded research projects (EU ECOLEADER project and EU FP7 SERIES/ BANDIT project). The aim of these experimental programmes was to investigate the effectiveness of externally bonded CFRP reinforcement in improving the seismic behaviour of deficiently designed RC buildings. To simulate typical substandard design, the reinforcement of beam-column joints and columns of the two full-scale frames had inadequate detailing. In both projects, initial shaking table tests were carried out to assess the seismic behaviour of the bare frame buildings. Columns and joints were subsequently repaired and strengthened using CFRP composite material for the ECOLEADER frame, and a strengthening solution consisting of CFRP composite material and Post-Tensioned Metal Straps for the BANDIT frame. The frames were then subjected to incremental seismic excitations to assess the effectiveness of the strengthening solutions in improving the global and local frame performance. Whilst the original bare frames were significantly damaged at a peak ground acceleration (PGA) of 0.15-0.20g, the strengthened frames resisted severe shaking table tests up to PGA=0.50-0.60g without failure. Moreover, the strengthening interventions enhanced the interstorey drift ratio capacity and proved to be very effective in addressing the seismic deficiencies of substandard buildings

    Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis C

    Get PDF
    The cost-effectiveness of noninvasive tests (NITs) as alternatives to liver biopsy is unknown. We compared the cost-effectiveness of using NITs to inform treatment decisions in adult patients with chronic hepatitis C (CHC). We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes (quality-adjusted life-years; QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four treatment strategies: testing with NITs and treating patients with fibrosis stage ≥F2; testing with liver biopsy and treating patients with ≥F2; treat none; and treat all irrespective of fibrosis. We compared all NITs and tested the cost-effectiveness using current triple therapy with boceprevir or telaprevir, but also modeled new, more-potent antivirals. Treating all patients without any previous NIT was the most effective strategy and had an incremental cost-effectiveness ratio (ICER) of £9,204 per additional QALY gained. The exploratory analysis of currently licensed sofosbuvir treatment regimens found that treat all was cost-effective, compared to using an NIT to decide on treatment, with an ICER of £16,028 per QALY gained. The exploratory analysis to assess the possible effect on results of new treatments, found that if SVR rates increased to >90% for genotypes 1-4, the incremental treatment cost threshold for the "treat all" strategy to remain the most cost-effective strategy would be £37,500. Above this threshold, the most cost-effective option would be noninvasive testing with magnetic resonance elastography (ICER=£9,189). Conclusions: Treating all adult patients with CHC, irrespective of fibrosis stage, is the most cost-effective strategy with currently available drugs in developed countries. © 2014 The Authors

    Mechanical properties of SFRC using blended manufactured and recycled tyre steel fibres

    Get PDF
    This paper investigates the mechanical properties of 10 steel fibre reinforced concrete (SFRC) mixes at fibre dosages of 30, 35 and 45 kg/m3. Manufactured Steel Fibres (MSF) are used on their own, or blended with sorted steel fibres recycled from end-of-life tyres (RTSF). To characterise the flexural behaviour of the mixes, two flexural test methods, BS EN 14651:2005 3-point notched prism tests and ASTM C1550-05 centrally loaded round panel tests are employed. A strong correlation is found in the flexural behaviour of the SFRC prism and round panel specimens, with corresponding conversion equations proposed. The mechanical properties of hybrid mixes using RTSF vary depending on dosages, but are comparable with those of MSF-only mixes at the same fibre dosage. A positive synergetic effect is derived from hybrid mixes containing 10 kg/m3 of RTSF

    Microcurrent stimulation in the treatment of dry and wet macular degeneration

    Get PDF
    Purpose: To determine the safety and efficacy of the application of transcutaneous (transpalpebral) microcurrent stimulation to slow progression of dry and wet macular degeneration or improve vision in dry and wet macular degeneration. Methods: Seventeen patients aged between 67 and 95 years with an average age of 83 years were selected to participate in the study over a period of 3 months in two eye care centers. There were 25 eyes with dry age-related macular degeneration (DAMD) and six eyes with wet age-related macular degeneration (WAMD). Frequency-specific microcurrent stimulation was applied in a transpalpebral manner, using two programmable dual channel microcurrent units delivering pulsed microcurrent at 150 μA for 35 minutes once a week. The frequency pairs selected were based on targeting tissues, which are typically affected by the disease combined with frequencies that target disease processes. Early Treatment Diabetic Retinopathy Study or Snellen visual acuity (VA) was measured before and after each treatment session. All treatment was administered in a clinical setting. Results: Significant increases were seen in VA in DAMD (P=0.012, Wilcoxon one-sample test), but in WAMD, improvements did not reach statistical significance (P=0.059). In DAMD eyes, twice as many patients showed increase in VA (52%) compared to those showing dete-rioration (26%), with improvements being often sizeable, whereas deteriorations were usually very slight. In WAMD eyes, five of six (83%) patients showed an increase and none showed deterioration. Conclusion: The substantial changes observed over this period, combined with continued improvement for patients who continued treatment once a month, are encouraging for future studies. The changes observed indicate the potential efficacy of microcurrent to delay degeneration and possibly improve age-related macular degeneration, both wet and dry. However, this study has no control arm, so results should be treated with caution. Randomized double-blind controlled studies are needed to determine long-term effects

    Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis B in the UK: systematic review and economic evaluation

    Get PDF
    The copyright line for this article was changed on 18 November 2016 after original online publication. Abbreviations: CEAF cost-effectiveness frontier. CHB chronic hepatitis B. CI confidence intervals. FN false negative. FP false positive. HBV hepatitis B virus. HCC hepatocellular carcinoma. ICER incremental cost-effectiveness ratio. NITs noninvasive tests. QUADAS Quality Assessment of Diagnostic Accuracy Studies. QUALYs quality-adjusted-life-years. TN true negative. TP true positive.Copyright © 2015 The Authors. We compared the cost-effectiveness of various noninvasive tests (NITs) in patients with chronic hepatitis B and elevated transaminases and/or viral load who would normally undergo liver biopsy to inform treatment decisions. We searched various databases until April 2012. We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes quality-adjusted-life-years (QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four decision-making strategies: testing with NITs and treating patients with fibrosis stage ≥F2, testing with liver biopsy and treating patients with ≥F2, treat none (watchful waiting) and treat all irrespective of fibrosis. Treating all patients without prior fibrosis assessment had an incremental cost-effectiveness ratio (ICER) of £28 137 per additional QALY gained for HBeAg-negative patients. For HBeAg-positive patients, using Fibroscan was the most cost-effective option with an ICER of £23 345. The base case results remained robust in the majority of sensitivity analyses, but were sensitive to changes in the ≥F2 prevalence and the benefit of treatment in patients with F0–F1. For HBeAg-negative patients, strategies excluding NITs were the most cost-effective: treating all patients regardless of fibrosis level if the high cost-effectiveness threshold of £30 000 is accepted; watchful waiting if not. For HBeAg-positive patients, using Fibroscan to identify and treat those with ≥F2 was the most cost-effective option.The analysis for Hepatitis B was part of a larger project funded by The National Institute for Health Research Health Technology Assessment (HTA project 09/114/02) and will be published in full in the Health Technology Assessment journal series. Visit the HTA programme website for more details www.hta.ac.uk/link to project page

    Spatial-spectral flexible optical networking:enabling switching solutions for a simplified and efficient SDM network platform

    Get PDF
    The traffic carried by core optical networks grows at a steady but remarkable pace of 30-40% year-over-year. Optical transmissions and networking advancements continue to satisfy the traffic requirements by delivering the content over the network infrastructure in a cost and energy efficient manner. Such core optical networks serve the information traffic demands in a dynamic way, in response to requirements for shifting of traffics demands, both temporally (day/night) and spatially (business district/residential). However as we are approaching fundamental spectral efficiency limits of singlemode fibers, the scientific community is pursuing recently the development of an innovative, all-optical network architecture introducing the spatial degree of freedom when designing/operating future transport networks. Spacedivision- multiplexing through the use of bundled single mode fibers, and/or multi-core fibers and/or few-mode fibers can offer up to 100-fold capacity increase in future optical networks. The EU INSPACE project is working on the development of a complete spatial-spectral flexible optical networking solution, offering the network ultra-high capacity, flexibility and energy efficiency required to meet the challenges of delivering exponentially growing traffic demands in the internet over the next twenty years. In this paper we will present the motivation and main research activities of the INSPACE consortium towards the realization of the overall project solution

    Promoting dental care to children using traditional and interactive media following threat appeals

    Get PDF
    In recent years, computer games have become an important part of children’s lives. Gaming is not only one of their favorite pastime activities, but games are also increasingly used by marketers in an attempt to influence children’s purchase behavior. Today, almost every food and beverage brand targeting children has an advergame on its website. Advergames are “computer games specifically created to function as advertisements to promote brands”, containing brand identifiers such as logos and brand characters (Kretchmer, 2005: 7). Games can also be powerful learning tools. Several authors (e.g., Gee, 2003; Prensky, 2001) argue that computer games can be more enjoyable, more interesting and thus more effective than traditional learning modes to increase children’s knowledge. Empirical studies that evaluated the impact of the use of games within disciplines such as mathematics, science, language, geography and computer science show positive outcomes in terms of learning effectiveness in relation to curricular objectives (e.g., Papastergiou, 2009; Rosas et al., 2003). However, these authors mainly focus on the learning ability of games rather than their persuasive impact for social marketing purposes. In the area of health education, playing computer games has often been seen with skepticism (e.g., Bale, 1994; Funk and Buchman, 1995)

    Inflammation-based scores do not predict post-transplant recurrence of hepatocellular carcinoma (HCC) in patients within Milan criteria.

    Get PDF
    Background: Increased preoperative inflammation scores, such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and inflammation-based index (IBI) have been related to post-transplant HCC recurrence. We evaluated the association between inflammation-based scores (NLR, PLR, IBI) and post-LT HCC recurrence as well as tumour necrosis after transarterial embolisation. Methods: 150 consecutive patients that were transplanted for HCC within the Milan criteria between 1996-2010 were included; data regarding inflammatory markers, patient and tumour characteristics were analyzed. Results: NLR, PLR and IBI were not significantly associated with post-LT HCC recurrence or worse overall survival. Increased NLR and PLR were associated with complete tumour necrosis in the subset of patients that received preoperative transarterial embolization (P<0.05). Cox regression analysis revealed that absence of neo-adjuvant transarterial therapy (OR=4.33, 95%CI 1.28-14.64; P=0.02) and no fulfilment of the Milan criteria in the explanted liver (OR=3.34, 95%CI 1.08-10.35; P=0.04) were independently associated with post-LT HCC recurrence. Conclusion: Inflammation-based scores did not predict HCC recurrence post-LT in our group of patients. NLR and PLR were associated with better response to TAE, as this was recorded histologically in the explanted liver. Histological fulfilment of the Milan criteria and absence of neo-adjuvant transarterial treatment were significantly associated with post-LT HCC recurrence. Liver Transpl , 2014. © 2014 AASLD

    Enabling transparent technologies for the development of highly granular flexible optical cross-connects

    Get PDF
    Flexible optical networking is identified today as the solution that offers smooth system upgradability towards Tb/s capacities and optimized use of network resources. However, in order to fully exploit the potentials of flexible spectrum allocation and networking, the development of a flexible switching node is required capable to adaptively add, drop and switch tributaries with variable bandwidth characteristics from/to ultra-high capacity wavelength channels at the lowest switching granularity. This paper presents the main concept and technology solutions envisioned by the EU funded project FOX-C, which targets the design, development and evaluation of the first functional system prototype of flexible add-drop and switching cross-connects. The key developments enable ultra-fine switching granularity at the optical subcarrier level, providing end-to-end routing of any tributary channel with flexible bandwidth down to 10Gb/s (or even lower) carried over wavelength superchannels, each with an aggregated capacity beyond 1Tb/s. © 2014 IEEE

    Designing Playful Games and Applications to Support Science Centers Learning Activities

    Get PDF
    In recent years there has been a renewed interest on science, technology, engineering, and mathematics (STEM) education. Following this interest, science centers\u27 staff started providing technology enhanced informal STEM education experiences. The use of well-designed mobile and ubiquitous forms of technology to enrich informal STEM education activities is an essential success factor. The goal of our research is to investigate how technology applications can be better used and developed for taking full advantage of the opportunities and challenges they provide for students learning about STEM concepts. In our approach, we have conducted a series of interviews with experts from science center curating and outdoor learning activities development, with the final goal of exploring and improving current learning environments and practices. This paper presents the development of set of design considerations for the development of STEM games and applications of young students. An initial set of best practices was first developed through semi-structures interviews with experts; and afterwards, by employing content analysis, a revised set of considerations was obtained. These results are useful for STEM education teachers, curriculum designers, curators and developers for K-12 education environments
    corecore