189 research outputs found

    Tidal energy machines: A comparative life cycle assessment

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    Marine energy in the UK is currently undergoing a period of exponential growth in terms of development and implementation. The current installed tidal energy capacity of around 4MW is expected to rise to provide up to 20% of the UK’s electricity demand by 2050 [5]. With this in mind, there is a huge range of energy devices, all seemingly promoted by their developers as the best method of extracting power from the ocean. Embodied energy is an important aspect of any power producing device or process, and is used to describe the amount of energy required to begin and maintain the process of energy generation. Until a device or process has generated this amount of energy it cannot be said to be a net contributor of energy. This work used Life Cycle Assessment to study four tidal energy devices, representing a cross section of the existing designs, and compares their embodied energy and carbon dioxide emissions. In order to ensure a fair comparison, a hypothetical installation site is used, with conditions typical of those found at potential array installation sites in the UK. The designs studied include a multi-blade turbine, two three blade horizontal axis turbine machines, and an Archimedes’ screw device. These machines were chosen to represent a cross section of device, foundation, installation and operation designs. They have all been developed to prototype stage, meaning that actual manufacturing data is available. Embodied energy is considered over the entire lifetime of each device, beginning with extraction of raw materials. Energy use from fabrication, transport, installation, lifetime maintenance, end-of-life decommissioning and recycling are all calculated, and compared to the energy generation from each device at the test site. Finally, the embodied energy; CO2 intensity; and energy payback periods are compared to those of conventional power generating systems as well as other renewable energy sources. A range of data sources are used. Embodied energy of steel has been provided by the World Steel Association. Of the four devices studied, all were found to achieve CO2 and energy payback within the first 12 years of their lifetime, and exhibited CO2 intensity of between 18 and 35 gCO2/kWh. This compares favourably to many current energy sources, and is likely to fall as technology improves, array size increases and industry experience progresses

    Posttyphoon prevalence of posttraumatic stress disorder, major depressive disorder, panic disorder, and generalized anxiety disorder in a Vietnamese sample

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    In 2006, typhoon Xangsane disrupted a multiagency health needs study of 4,982 individuals in Vietnam. Following this disaster, 798 of the original participants were reinterviewed to determine prevalence and risk factors associated with posttraumatic stress disorder (PTSD), major depressive disorder (MDD), panic disorder (PD), and generalized anxiety disorder (GAD). Posttyphoon prevalences were PTSD 2.6%, MDD 5.9%, PD 9.3%, and GAD 2.2%. Of those meeting criteria for a disorder, 70% reported only one disorder, 15% had two, 14% had three, and 1% met criteria for all four disorders. Risk factors for posttyphoon psychopathology differed among disorders, but generally were related to high typhoon exposure, prior trauma exposure, and in contrast to Western populations, higher age, but not gender.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63069/1/20404_ftp.pd

    Region prioritization for the development carbon capture and utilization technologies

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    In recent years several strategies have been developed and adopted to reduce the levels of the Greenhouse Gas Emissions emitted to the atmosphere. The adoption of Carbon Capture and Utilization (CCU) technologies may contribute towards carbon sequestration as well as to the creation of high value products. This study presents a methodology to assess the potential of CO2utilization across Europe, and to identify the European regions with the greater potential to deploy nine selected carbon dioxide utilization technologies. The results show that Germany, UK and France at the first level followed by Spain, Italy and Poland are the countries where the larger quantities of available CO2 could be found but also where the majority of the potential receiving processes are located, and therefore with the greatest potential for CO2 utilization. The study has also revealed several specific regions where reuse schemes based on CO2 could be developed both in Central Europe (Dusseldorf and Cologne – Germany, Antwerp Province and East Flanders –Belgium and Śląskie – Poland) and in Scandinavia (Etelä-Suomi and Helsinki-Uusimaa –Finland). Finally, among all the selected technologies, concrete curing and horticulture production are the technologies with the higher potential for CO2 utilization in Europe

    Estimates of probable dementia prevalence from population-based surveys compared with dementia prevalence estimates based on meta-analyses

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    <p>Abstract</p> <p>Background</p> <p>National data on dementia prevalence are not always available, yet it may be possible to obtain estimates from large surveys that include dementia screening instruments. In Australia, many of the dementia prevalence estimates are based on European data collected between 15 and 50 years ago. We derived population-based estimates of probable dementia and possible cognitive impairment in Australian studies using the Mini-Mental State Examination (MMSE), and compared these to estimates of dementia prevalence from meta-analyses of European studies.</p> <p>Methods</p> <p>Data sources included a pooled dataset of Australian longitudinal studies (DYNOPTA), and two Australian Bureau of Statistics National Surveys of Mental Health and Wellbeing. National rates of probable dementia (MMSE < 24) and possible cognitive impairment (24-26) were estimated using combined sample weights.</p> <p>Results</p> <p>Estimates of probable dementia were higher in surveys than in meta-analyses for ages 65-84, but were similar at ages 85 and older. Surveys used weights to account for sample bias, but no adjustments were made in meta-analyses. Results from DYNOPTA and meta-analyses had a very similar pattern of increase with age. Contrary to trends from some meta-analyses, rates of probable dementia were not higher among women in the Australian surveys. Lower education was associated with higher prevalence of probable dementia. Data from investigator-led longitudinal studies designed to assess cognitive decline appeared more reliable than government health surveys.</p> <p>Conclusions</p> <p>This study shows that estimates of probable dementia based on MMSE in studies where cognitive decline and dementia are a focus, are a useful adjunct to clinical studies of dementia prevalence. Such information and may be used to inform projections of dementia prevalence and the concomitant burden of disease.</p

    Women in post-trafficking services in moldova: diagnostic interviews over two time periods to assess returning women's mental health

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    BACKGROUND: Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country. METHODS: A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months) were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return) and the re-integration phase (2-12 months after return). We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table). RESULTS: 120/176 (68%) eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD) alone (16%); co-morbid PTSD (20%); other anxiety or mood disorder (18%). 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation. CONCLUSIONS: Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women found to have co-morbid PTSD or other forms of anxiety and depression immediately post-return should be offered evidenced-based mental health treatment for at least the standard 12-month period of rehabilitation
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