10,322 research outputs found

    Bioavailability of soil organic carbon and Fe as influenced by forestry practices in a subtropical coastal catchment

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    Potential impacts of plantation forestry practices on soil organic carbon and Fe available to microorganisms were investigated in a subtropical coastal catchment. The impacts of harvesting or replanting were largely limited to the soil top layer (0–10 cm depth). The thirty-year-old Pinus plantation showed low soil moisture content (Wc) and relatively high levels of soil total organic carbon (TOC). Harvesting and replanting increased soil Wc but reduced TOC levels. Mean dissolved organic carbon (DOC) and microbial biomass carbon (MBC) increased in harvested or replanted soils, but such changes were not statistically significant (P > 0.05). Total dithionite-citrate and aqua regia-extractable Fe did not respond to forestry practices, but acid ammonium oxalate and pyrophosphate-extractable, bioavailable Fe decreased markedly after harvesting or replanting. Numbers of heterotrophic bacteria were significantly correlated with DOC levels (P < 0.05), whereas Fe-reducing bacteria and S-bacteria detected using laboratory cultivation techniques did not show strong correlation with either soil DOC or Fe content

    Master of Arts

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    thesisThis thesis analyzes the Palestinian national movement between 1917 and 1939. It focuses on the social structure and economic problems in Palestinian Arab society and how these factors contributed to the political challenges that confronted the national leadership. The Palestinian Arab leaders of this era are remembered today for their unwillingness to accept the terms of the British Mandate. Their position stayed more or less consistent throughout the period under review, as did their opposition to Jewish land purchase and immigration to the region. These were the two major tenets of the Zionist movement and critical objectives of the mandate itself. The continued opposition of the Palestinian leaders and the persistence of the issues they faced did not amount to a static situation. There were various social and economic changes taking place in Palestine. These changes adversely affected the lower classes and weakened the position of the ruling class. As the plight of the Palestinians worsened, the national leaders remained caught in political gridlock that further eroded their position. In addition to these factors, there were outside forces that determined the trajectory of the Palestine mandate and the state of its Arab population

    A Systems Analysis of Factors that Lead to the Successful Employment of People with a Disability

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    BACKGROUND: Disability Employment Services (DES) is the primary vehicle in Australia charged with promoting and supporting successful open employment opportunities for people with intellectual and developmental disabilities. This research examined the client consultant dynamic to see what factors were at play in promoting successful employment. METHOD: Research was undertaken using a Multiple Perspective Design that resides within the Interpretative Phenomenological Analysis methodology. Clients with a wide variety of ID/DD (n=24) and Employment Consultants (n=23) were interviewed using semi-structured interviews in small group settings. The data were analysed using Interpretative Phenomenological Analysis (IPA) that allowed for themes to be developed. RESULTS: The research highlighted five primary themes: Relationships, Processes, Compliance Driven Systems, Employers and the Environment. These themes provide a base to develop an understanding of some of the factors influencing employment outcomes amongst the client participant base and the disability employment consultants. The results highlighted disparities in perceived abilities, attitudes and a lack of understanding between the system participants. The results also highlighted the influence of ecology on employment outcomes and a high level of disequilibrium within the employment system and environment. IMPLICATIONS: The inability of the disability employment system to use known evidence-based processes that support clients with ID/DD and consultants has resulted in a system that lacks any real understanding of the client and consultant needs, placing primacy on compliance and system needs ahead of the stated purpose of the program which is to support people with a disability to gain and maintain meaningful employment consistent with their capacity and career aspirations. The research highlights the importance of relationships in creating real understanding of the client to supporting employment outcomes

    Acidified and ultrafiltered recovered coagulants from water treatment works sludge for removal of phosphorus from wastewater

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    This study used a range of treated water treatment works sludge options for the removal of phosphorus (P) from primary wastewater. These options included the application of ultrafiltration for recovery of the coagulant from the sludge. The treatment performance and whole life cost (WLC) of the various recovered coagulant (RC) configurations have been considered in relation to fresh ferric sulphate (FFS). Pre-treatment of the sludge with acid followed by removal of organic and particulate contaminants using a 2kD ultrafiltration membrane resulted in a reusable coagulant that closely matched the performance FFS. Unacidified RC showed 53% of the phosphorus removal efficiency of FFS, at a dose of 20 mg/L as Fe and a contact time of 90 min. A longer contact time of 8 h improved performance to 85% of FFS. P removal at the shorter contact time improved to 88% relative to FFS by pre-acidifying the sludge to pH 2, using an acid molar ratio of 5.2:1 mol H+:Fe. Analysis of the removal of P showed that rapid phosphate precipitation accounted for >65% of removal with FFS. However, for the acidified RC a slower adsorption mechanism dominated; this was accelerated at a lower pH. A cost-benefit analysis showed that relative to dosing FFS and disposing waterworks sludge to land, the 20 year WLC was halved by transporting acidified or unacidified sludge up to 80 km for reuse in wastewater treatment. A maximum inter-site distance was determined to be 240 km above the current disposal route at current prices. Further savings could be made if longer contact times were available to allow greater P removal with unacidified RC

    Planar micromachined glass cantilevers utilising integrated Bragg Fabry-Perot cavities

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    Here we demonstrate a glass cantilever based on a unique micromachining and etching approach, combined with UV written Bragg gratings. We shall also discuss the increase in sensitivity by using two Bragg gratings to form Fabry-Pérot cavity. Cantilevers are in ultra sensitive force sensors used in applications such as Atomic Force Microscopy, mass sensing and acoustic transducers

    Coagulant recovery and reuse for drinking water treatment

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    Coagulant recovery and reuse from waterworks sludge has the potential to significantly reduce waste disposal and chemicals usage for water treatment. Drinking water regulations demand purification of recovered coagulant before they can be safely reused, due to the risk of disinfection by-product precursors being recovered from waterworks sludge alongside coagulant metals. While several full-scale separation technologies have proven effective for coagulant purification, none have matched virgin coagulant treatment performance. This study examines the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies to attain virgin coagulant purity levels. The new suggested approach of alkali extraction of dissolved organic compounds (DOC) from waterworks sludge prior to acidic solubilisation of ferric coagulants provided the same 14:1 selectivity ratio (874 mg/L Fe vs. 61 mg/L DOC) to the more established size separation using ultrafiltration (1285 mg/L Fe vs. 91 mg/L DOC). Cation exchange Donnan membranes were also examined: while highly selective (2555 mg/L Fe vs. 29 mg/L DOC, 88:1 selectivity), the low pH of the recovered ferric solution impaired subsequent treatment performance. The application of powdered activated carbon (PAC) to ultrafiltration or alkali pre-treated sludge, dosed at 80 mg/mg DOC, reduced recovered ferric DOC contamination to <1 mg/L but in practice, this option would incur significant costs. The treatment performance of the purified recovered coagulants was compared to that of virgin reagent with reference to key water quality parameters. Several PAC-polished recovered coagulants provided the same or improved DOC and turbidity removal as virgin coagulant, as well as demonstrating the potential to reduce disinfection byproducts and regulated metals to levels comparable to that attained from virgin material

    Reuse of recovered coagulants in water treatment: An investigation on the effect coagulant purity has on treatment performance

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    Coagulant recovery offers many potential benefits to water treatment, by reducing chemical demand and waste production. The key obstacle to successful implementation is achieving the same levels of treatment quality and process economics as commercial coagulants. This study has evaluated the selectivity of pressure-filtration in the role of a low-cost coagulant recovery technology from waterworks sludge. The treatment performance of the purified recovered coagulant was directly compared to fresh and raw recovered coagulants. DOC and turbidity removal by recovered coagulants was close to that of commercial coagulants, indicating that coagulant can be successfully recovered and regenerated by acidifying waterworks sludge. However, performance was less consistent, with a much narrower optimum charge neutralisation window and 10–30% worse removal performance under optimum conditions. This inferior performance was particularly evident for recovered ferric coagulants. The impact of this was confirmed by measuring THM formation potential and residual metals concentrations, showing 30–300% higher THMFPs when recovered coagulants were used. This study confirms that pressure-filtration can be operated on an economically viable basis, in terms of mass flux and fouling. However, the selectivity currently falls short of the purity required for potable treatment, due to incomplete rejection of sludge contaminants

    Promoting inquiry skills in Curriculum for Excellence in Science: conceptualising inquiry to improve practice

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    This paper describes a Scottish initiative (arising out of a EU funded development project) involving university researchers, a local authority curriculum development officer and a group of teachers interested in developing more inquiry based approaches in science education. The project is not one in which the researchers bring prescriptions from research. Rather, it is seen as a joint effort aimed at solving practitioners' conceptual and practice issues. The overall question for the teachers was, How do I (we) make our practice more inquiry based? The question for the researchers was, How do we help you (the interested science teachers) to make your practice more inquiry based? This has two sub-questions: How do we help you to conceptualise the issues? How do we help you to solve the practice problems? As it turned out, the particular group of teachers we worked with did not ask for help with practice issues, so we have not made much progress in answering the second question. Therefore, this paper will focus on the first. We seem to have been successful in helping the teachers to acquire some useful conceptual tools for thinking about and changing their practice in ways that they valued for themselves. Perhaps the answer to the second question is that researchers can help teachers to solve their practice problems by helping them to conceptualise the issues

    Promoting Inquiry in Science Classrooms in European Schools : a Handbook for Tutors

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    In Scotland, PISCES stands for Promoting Inquiry Skills for a Curriculum for Excellence in Science. It is a CPD module for teachers of science, which has been developed in Scotland with the support of the S-TEAM project. However, this Handbook uses our international acronym in which PISCES stands for Promoting Inquiry in Science Classrooms in European Schools . It is, we believe, potentially equally as successful across Europe as it was designed around the idea of empowering teachers to think for themselves how to make their practice more-inquiry based, wherever they are. It is recognised that some school, social, policy and cultural environments may be more supportive of the idea of ‘more inquiry-based practice’ than others. PISCES empowers teachers to make small or large changes to their practice, according to those sorts of contextual factors, their own aims and how they perceive the needs of their pupils. You will note that we have been careful to use the word ‘more’ in ‘more inquiry-based.’ As befits the idea of empowerment to adapt to one’s own context, there is no single model of inquiry being ‘pushed’ here. Indeed, we count it as a measure of success of PISCES that the teachers who have participated did very different things in making their practice more inquiry-based. Strathclyde University is a leading partner in S-TEAM. Members of Strathclyde University, along with the Development Officer for Curriculum for Excellence for East Lothian, successfully developed and delivered a pilot version of PISCES as a module to a group of East Lothian teachers, in 2010/11. The module resulted in successful ‘experiments in practice’ and increased awareness of the benefits of inquiry-based teaching and learning. The same group of teachers have also taken part in a follow-up course (ARIES: Advanced Resources for Inquiry and Evaluation in Science). PISCES is a high quality CPD programme, valued by teachers and supportive of their professional self-development. It can be applied to both primary and secondary teaching, in all science subjects. Pupils benefit from learning experiences, which develop scientific inquiry skills. Feedback from participating teachers has been consistently positive

    Space optics contributions by the College of Optical Sciences over the past 50 years

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    We present a review of the contributions by students, staff, faculty and alumni to the Nation’s space program over the past 50 years. The balloon polariscope led the way to future space optics missions. The missions Pioneer Venus (large probe solar flux radiometer), Pioneer 10/11 (imaging photopolarimeter) to Jupiter and Saturn, Hubble Space Telescope (HST), and next generation large aperture space telescopes are discussed
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