254,110 research outputs found

    Environmental performance of rainwater harvesting strategies in Mediterranean buildings

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    Purpose: The rapid urbanization and the constant expansion of urban areas during the last decades have locally led to increasing water shortage. Rainwater harvesting (RWH) systems have the potential to be an important contributor to urban water self-sufficiency. The goal of this study was to select an environmentally optimal RWH strategy in newly constructed residential buildings linked to rainwater demand for laundry under Mediterranean climatic conditions, without accounting for water from the mains. Methods: Different strategies were environmentally assessed for the design and use of RWH infrastructures in residential apartment blocks in Mediterranean climates. The harvested rainwater was used for laundry in all strategies. These strategies accounted for (i) tank location (i.e., tank distributed over the roof and underground tank), (ii) building height considering the number of stories (i.e., 6, 9, 12, and 15), and (iii) distribution strategy (i.e., shared laundry, supply to the nearest apartments, and distribution throughout the building). The RWH systems consisted of the catchment, storage, and distribution stages, and the structural and hydraulic calculations were based on Mediterranean conditions. The quantification of the environmental performance of each strategy (e.g., CO2eq. emissions) was performed in accordance with the life cycle assessment methodology. Results and discussion: According to the environmental assessment, the tank location and distribution strategy chosen were the most important variables in the optimization of RWH systems. Roof tank strategies present fewer impacts than their underground tank equivalents because they enhance energy and material savings, and their reinforcement requirements can be accounted for within the safety factors of the building structure without the tank. Among roof tanks and depending on the height, a distribution strategy that concentrates demand in a laundry room was the preferable option, resulting in reductions from 25 to 54 % in most of the selected impact categories compared to distribution throughout the building. Conclusions: These results may set new urban planning standards for the design and construction of buildings from the perspective of sustainable water management. In this sense, a behavioral change regarding demand should be promoted in compact, dense urban settlements.Peer ReviewedPostprint (author's final draft

    Youth and Digital Media: From Credibility to Information Quality

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    Building upon a process-and context-oriented information quality framework, this paper seeks to map and explore what we know about the ways in which young users of age 18 and under search for information online, how they evaluate information, and how their related practices of content creation, levels of new literacies, general digital media usage, and social patterns affect these activities. A review of selected literature at the intersection of digital media, youth, and information quality -- primarily works from library and information science, sociology, education, and selected ethnographic studies -- reveals patterns in youth's information-seeking behavior, but also highlights the importance of contextual and demographic factors both for search and evaluation. Looking at the phenomenon from an information-learning and educational perspective, the literature shows that youth develop competencies for personal goals that sometimes do not transfer to school, and are sometimes not appropriate for school. Thus far, educational initiatives to educate youth about search, evaluation, or creation have depended greatly on the local circumstances for their success or failure

    Security Incident Response Criteria: A Practitioner's Perspective

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    Industrial reports indicate that security incidents continue to inflict large financial losses on organizations. Researchers and industrial analysts contend that there are fundamental problems with existing security incident response process solutions. This paper presents the Security Incident Response Criteria (SIRC) which can be applied to a variety of security incident response approaches. The criteria are derived from empirical data based on in-depth interviews conducted within a Global Fortune 500 organization and supporting literature. The research contribution of this paper is twofold. First, the criteria presented in this paper can be used to evaluate existing security incident response solutions and second, as a guide, to support future security incident response improvement initiatives

    Living with Privatization: At Work and in the Community

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    Jerry L. Marshaw moderates this panel discussion with Cathlin Baker, Sheryll D. Cashin, John D. Donahue, Hon. Floyd Flake, Eugene W. Harper Jr. and Kerry Korpi

    Charting a New Course to Retirement: How Charter Schools Handle Teacher Pensions

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    In this "Ed Short" from the Thomas B. Fordham Institute, Amanda Olberg and Michael Podgursky examine how public charter schools handle pensions for their teachers. Some states give these schools the freedom to opt out of the traditional teacher-pension system; when given that option, how many charter schools take it? Olberg and Podgursky examine data from six charter-heavy states and find that charter participation rates in traditional pension systems vary greatly -- from over 90 percent in California to less than one out of every four charters in Florida. As for what happens when schools choose not to participate in state pension plans, the authors find that they most often provide their teachers with defined-contribution plans (401(k) or 403(b)) with employer matches similar to those for private-sector professionals. But some opt-out charters offer no alternative retirement plans for their teachers (18 percent in Florida, 24 percent in Arizona)

    Water footprint of bio-energy and other primary energy carriers

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    Freshwater is essential for life on earth, not only for basic human needs such as food, fibre and drinking water, but also for a healthy environment. In the near future, important challenges are to meet basic needs and to ensure that the extraction of water does not affect freshwater ecosystems. At present, humanity already uses 26 percent of the total terrestrial evapotranspiration and 54 percent of accessible runoff. If the world population increases further, there is concern in several regions and countries with limited water resources if food and fibre needs of future generations can be met. In general, global change is often considered in relation to climate change caused by emissions of greenhouse gasses, such as CO2 from fossil energy carriers. A shift towards CO2-neutral energy carriers, such as biomass, is heavily promoted. Nowadays, the production of biomass for food and fibre in agriculture requires about 86% of the worldwide freshwater use often competing with other uses such as urban supply and industrial activities. A shift from fossil energy towards energy from biomass puts additional pressure on freshwater resources. This report assesses the water footprint (WF) of bio-energy and other primary energy carriers. It focuses on primary energy carriers and expresses the WF as the amount of water consumed to produce a unit of energy (m3/GJ). The report observes large differences among the WF’s for specific types of primary energy carriers. For the fossil energy carriers, the WF increases in the following order: uranium (0.09 m3/GJ), natural gas (0.11 m3/GJ), coal (0.16 m3/GJ), and finally crude oil (1.06 m3/GJ). Renewable energy carriers show large differences in their WF. The WF for wind energy is negligible, for solar thermal energy 0.30 m3/GJ, but for hydropower 22.3 m3/GJ. For biomass, the WF depends on crop type, agricultural production system and climate. The WF of average biomass grown in the Netherlands is 24 m3/GJ, in the US 58 m3/GJ, in Brazil 61 m3/GJ, and in Zimbabwe 143 m3/GJ. Based on the average per capita energy use in western societies (100 GJ/capita/year), a mix from coal, crude oil, natural gas and uranium requires about 35 m3/capita/year. If the same amount of energy is generated through the growth of biomass in a high productive agricultural system, as applied in the Netherlands, the WF is 2420 m3. The WF of biomass is 70 to 400 times larger than the WF of the other primary energy carriers (excluding hydropower). The trend towards larger energy use in combination with increasing contribution of energy from biomass to supply will bring with it a need for more water. This causes competition with other claims, such as water for food crops

    Source control SUDS strategic directions

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    Background to researchThe uptake or transition from traditional drainage to sustainable drainage (SUDS) in Scotland has happened in a relatively short timescale (less than fifteen years) with site and regional control drainage structures such as ponds and basins now considered ‘business as usual’. This rapid transition to SUDS has been facilitated by a stakeholder platform called the Sustainable Urban Drainage Scottish Working Party (SUDSWP) which has promoted their use since 1997. This has subsequently led to Scotland being regarded as a frontrunner in SUDS implementation in the UK. However the uptake of source control as part of a stormwater treatment train is less routine than expected. With the aforementioned in mind, this Phase Three Report seeks to answer the question ‘How can the national uptake of source control be encouraged and influenced by the SUDS Working Party and whether they should recast their remit’? Objectives of research Phase One of this research looked at the background to the evolution of source control in Scotland providing preliminary insight into the enabling factors and obstacles for uptake of the systems since inception in the mid 1990’s. Phase Two appraised source control delivery on a global scale providing insight to enabling factors out with Scotland and appraising current delivery in Scotland by responsible organisations. The transition pathway from traditional drainage to source control SUDS was mapped out to highlight what the key enabling (and disabling) factors were to realise the transition to date. This phase of the research, Phase Three defines the next steps including comment on optimal source control and further considerations and recommendations. This involved analysis and consolidation of the findings from Phases one and two, a workshop delivered to SUDSWP and two surveys delivered online and via telephone interviews with professionals involved in source control SUDS. These findings are used to define barriers and opportunities to inform the development of a strategy to support and encourage implementation of source control within SUDSWP remit.Key findings and recommendationsKey findings and recommendations for the SUDS Working Party are grouped according to transition management cluster activities:* Transition Arena: Strengthen links with internal members and external stakeholders who have a stake in source control SUDS and develop an integrated long-term vision.* Transition Agenda: Develop a shared strategic plan which considers aligning agendas with other infrastructure initiatives and enforcement / inspection policies to ensure cost effective, fit for purpose measures particularly in the areas of unit plot, local streets and regeneration areas.* Transition Experiments / case studies: Encourage research partnerships to validate techniques in the source control toolkit not yet applied in Scotland and showcase case studies.* Transition Monitoring / evaluation: undertake a baseline assessment to gauge source control uptake and performance, revise existing guidance and encourage capacity building programmes.<br/
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