309 resultados para fenoli adsorbimento green chemistry HPLC
Resumo:
This study explores the development of a coding system for analysing test questions in two context-based chemistry exams. We describe our unique analytical procedures before contrasting the data from both tests. Our findings indicate that when a new curriculum is developed such as a context-based curriculum, teachers are required to combine the previously separate domains of context and concept to develop contextualised assessment. We argue that constructing contextualised assessment items requires teachers to view concepts and context as interconnected rather than as separate entities that may polarise scientific endeavour. Implications for practice, curriculum and assessment-development in context-based courses are proposed.
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This study investigated whether conceptual development is greater if students learning senior chemistry hear teacher explanations and other traditional teaching approaches first then see computer based visualizations or vice versa. Five Canadian chemistry classes, taught by three different teachers, studied the topics of Le Chatelier’s Principle and dynamic chemical equilibria using scientific visualizations with the explanation and visualizations in different orders. Conceptual development was measured using a 12 item test based on the Chemistry Concepts Inventory. Data was obtained about the students’ abilities, learning styles (auditory, visual or kinesthetic) and sex, and the relationships between these factors and conceptual development due to the teaching sequences were investigated. It was found that teaching sequence is not important in terms of students’ conceptual learning gains, across the whole cohort or for any of the three subgroups.
Resumo:
Scientific visualisations such as computer-based animations and simulations are increasingly a feature of high school science instruction. Visualisations are adopted enthusiastically by teachers and embraced by students, and there is good evidence that they are popular and well received. There is limited evidence, however, of how effective they are in enabling students to learn key scientific concepts. This paper reports the results of a quantitative study conducted in Australian physics and chemistry classrooms. In general there was no statistically significant difference between teaching with and without visualisations, however there were intriguing differences around student sex and academic ability.
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Visual modes of representation have always been very important in science and science education. Interactive computer-based animations and simulations offer new visual resources for chemistry education. Many studies have shown that students enjoy learning with visualisations but few have explored how learning outcomes compare when teaching with or without visualisations. This study employs a quasi-experimental crossover research design and quantitative methods to measure the educational effectiveness - defined as level of conceptual development on the part of students - of using computer-based scientific visualisations versus teaching without visualisations in teaching chemistry. In addition to finding that teaching with visualisations offered outcomes that were not significantly different from teaching without visualisations, the study also explored differences in outcomes for male and female students, students with different learning styles (visual, aural, kinesthetic) and students of differing levels of academic ability.
Resumo:
Enormous amounts of money and energy are being devoted to the development, use and organisation of computer-based scientific visualisations (e.g. animations and simulations) in science education. It seems plausible that visualisations that enable students to gain visual access to scientific phenomena that are too large, too small or occur too quickly or too slowly to be seen by the naked eye, or to scientific concepts and models, would yield enhanced conceptual learning. When the literature is searched, however, it quickly becomes apparent that there is a dearth of quantitative evidence for the effectiveness of scientific visualisations in enhancing students’ learning of science concepts. This paper outlines an Australian project that is using innovative research methodology to gather evidence on this question in physics and chemistry classrooms.
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The relationship between the environment and human rights has long been recognised. It is now largely accepted that a ‘good’ environment is a necessary precondition for the enjoyment of a wide range of human rights, including the right to health, the right to an adequate standard of living, and even the right to life. It has even been suggested that as humans we all possess a right to live in an environment of a certain standard, based on the intrinsic value of the natural world to all human beings. In this context much has been written regarding the important role that the environment plays in human lives. This paper looks at the flip-side of this discussion, and examines what human rights can do for the environment. It is argued that, while there are valid criticisms for linking environmental protection too strongly to human needs, there is nonetheless much to be gained from using human rights law as a framework to achieve environmental protection.
An experimental and computational investigation of performance of Green Gully for reusing stormwater
Resumo:
A new stormwater quality improvement device (SQID) called ‘Green Gully’ has been designed and developed in this study with an aim to re-using stormwater for irrigating plants and trees. The main purpose of the Green Gully is to collect road runoff/stormwater, make it suitable for irrigation and provide an automated network system for watering roadside plants and irrigational areas. This paper presents the design and development of Green Gully along with experimental and computational investigations of the performance of Green Gully. Performance (in the form of efficiency, i.e. the percentage of water flow through the gully grate) was experimentally determined using a gully model in the laboratory first, then a three dimensional numerical model was developed and simulated to predict the efficiency of Green Gully as a function of flow rate. Computational Fluid Dynamics (CFD) code FLUENT was used for the simulation. GAMBIT was used for geometry creation and mesh generation. Experimental and simulation results are discussed and compared in this paper. The predicted efficiency was compared with the laboratory measured efficiency. It was found that the simulated results are in good agreement with the experimental results.
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Buildings are one of the most significant infrastructures in modern societies. The construction and operation of modern buildings consume a considerable amount of energy and materials, therefore contribute significantly to the climate change process. In order to reduce the environmental impact of buildings, various green building rating tools have been developed. In this paper, energy uses of the building sector in Australia and over the world are first reviewed. This is then followed by discussions on the development and scopes of various green building rating tools, with a particular focus on the Green Star rating scheme developed in Australia. It is shown that Green Star has significant implications on almost every aspect of the design of HVAC systems, including the selection of air handling and distribution systems, fluid handling systems, refrigeration systems, heat rejection systems and building control systems.
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Context-based chemistry education aims to improve student interest and motivation in chemistry by connecting canonical chemistry concepts with real-world contexts. Implementation of context-based chemistry programmes began 20 years ago in an attempt to make the learning of chemistry meaningful for students. This paper reviews such programmes through empirical studies on six international courses, ChemCom (USA), Salters (UK), Industrial Science (Israel), Chemie im Kontext (Germany), Chemistry in Practice (The Netherlands) and PLON (The Netherlands). These studies are categorised through emergent characteristics of: relevance, interest/attitudes motivation and deeper understanding. These characteristics can be found to an extent in a number of other curricular initiatives, such as science-technology-society approaches and problem-based learning or project based science, the latter of which often incorporates an inquiry-based approach to science education. These initiatives in science education are also considered with a focus on the characteristics of these approaches that are emphasised in context-based education. While such curricular studies provide a starting point for discussing context-based approaches in chemistry, to advance our understanding of how students connect canonical science concepts with the real-world context, a new theoretical framework is required. A dialectical sociocultural framework originating in the work of Vygotsky is used as a referent for analysing the complex human interactions that occur in context-based classrooms, providing teachers with recent information about the pedagogical structures and resources that afford students the agency to learn.
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Concerns regarding groundwater contamination with nitrate and the long-term sustainability of groundwater resources have prompted the development of a multi-layered three dimensional (3D) geological model to characterise the aquifer geometry of the Wairau Plain, Marlborough District, New Zealand. The 3D geological model which consists of eight litho-stratigraphic units has been subsequently used to synthesise hydrogeological and hydrogeochemical data for different aquifers in an approach that aims to demonstrate how integration of water chemistry data within the physical framework of a 3D geological model can help to better understand and conceptualise groundwater systems in complex geological settings. Multivariate statistical techniques(e.g. Principal Component Analysis and Hierarchical Cluster Analysis) were applied to groundwater chemistry data to identify hydrochemical facies which are characteristic of distinct evolutionary pathways and a common hydrologic history of groundwaters. Principal Component Analysis on hydrochemical data demonstrated that natural water-rock interactions, redox potential and human agricultural impact are the key controls of groundwater quality in the Wairau Plain. Hierarchical Cluster Analysis revealed distinct hydrochemical water quality groups in the Wairau Plain groundwater system. Visualisation of the results of the multivariate statistical analyses and distribution of groundwater nitrate concentrations in the context of aquifer lithology highlighted the link between groundwater chemistry and the lithology of host aquifers. The methodology followed in this study can be applied in a variety of hydrogeological settings to synthesise geological, hydrogeological and hydrochemical data and present them in a format readily understood by a wide range of stakeholders. This enables a more efficient communication of the results of scientific studies to the wider community.
Resumo:
This report discusses findings of a case study into "Green Buildings" undertaken as a part of the retrospective analysis component of Sustainable Built Environment National Research Centre (SBEnrc) Project 2.7 Leveraging R&D investment for the Australian Built Environment. The Western Australian Government (WAG) has taken a leadership role for a number of decades in developing more environmentally responsive buildings. In the past decade, considerable initiatives have been introduced to contribute to: (i) greening the stock of government buildings; and (ii) providing leadership in the development of other non-residential buildings developed commercially. This role has been informed by global, national and internal initiatives and research in this area. This case study investigates: (i) the nature of this leadership; and (ii) the role of R&D policy development; and (iii) the dissemination and impact of outcomes in the broader industry. This case study should be read in conjunction with Part 1 of this suite of reports.
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Purpose With an increasingly ageing population and widespread acceptance of the need for sustainable development in Australia, the demand for green retirement villages is increasing. This paper aims to identify the critical issues to be considered by developers and practitioners when embarking on their first green residential retirement project in Australia. Design/methodology/approach In view of the lack of adequate historical data for quantitative analysis, a case study approach is employed to examine the successful delivery of green retirement villages. Face-to-face interviews and document analysis were conducted for data collection. Findings The findings of the study indicate that one of the major obstacles to the provision of affordable green retirement villages is the higher initial costs involved. However, positive aspects were identified, the most significant of which relate to: the innovative design of site and floor plans; adoption of thermally efficient building materials; orientation of windows; installation of water harvesting and recycling systems, water conservation fittings and appliances; and waste management during the construction stage. With the adoption of these measures, it is believed that sustainable retirement development can be achieved without significant additional capital costs. Practical implications The research findings serve as a guide for developers in decision making throughout the project life-cycle when introducing green features into the provision of affordable retirement accommodation. Originality/value This paper provides insights into the means by which affordable green residential retirement projects for aged people can be successfully completed.
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Processing of juice expressed from green sugar cane containing all the trash (i.e., tops and leaves, the nonstalk component) of the sugar cane plant during sugar manufacture has been reported to lead to poor clarified juice (CJ) quality. Studies of different liming techniques have been conducted to identify which liming technique gives the best clarification performance from juice expressed from green cane containing half of all trash extracted (GE). Results have shown that lime saccharate addition to juice at 76 °C either continuous or batchwise gives satisfactory settling rates of calcium phosphate flocs(50−70 cm/min) and CJ with low turbidity and minimal amounts of mineral constituents. Surprisingly, the addition of phosphoric acid (≤300 mg/kg as P2O5), prior to liming to reduce juice turbidity (≤80%), increased the Mg (≤101%) and Si(≤148%) contents particularly for clarified GE juices. The increase was not proportional with increasing phosphoric acid dose. The nature of the flocs formed, including the zeta potential of the particles by the different liming techniques, has been used to account for the differences in clarification performance. Differences between the qualities of the CJ obtained with GE juice and that of burnt cane juices with all trash extracted (BE) have been discussed to provide further insights into GE processing.
Resumo:
Background: The term ‘green health promotion’ is given to health promotion underpinned by the principles of ecological health and sustainability. Green health promotion is supported philosophically by global health promotion documents such as the Ottawa Charter for Health Promotion (1986) and the ecological public health movement. Green health promotion in schools aims to practice the principles of ecological health and sustainability. Methods: An extended literature review revealed a paucity of literature about green health promotion in schools across disciplines. Literature about nurses and health promotion in schools is generally found in nursing publications. Literature about ecological sustainability in schools is mostly found in teaching publications. Results: This paper explores the nexus between nursing and health promotion, and teachers and ecological sustainability. Collaborative partnerships between health and education do not capitalise on programs such as Health Promoting Schools and the School Based Youth Health Nurse Program in Queensland, Australia. The authors consider how collaborative partnerships between health and education in schools can work towards green health promotion. Conclusion: Nursing’s approach to health promotion and education’s approach to ecological sustainability need to be aligned to enhance green health promotion in schools and promote a new generation of ‘tree huggers and hippies’.
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20 and 26 S proteasomes were isolated from rat liver. The procedure developed for the 26 S proteasome resulted in greatly improved yields compared with previously published methods. A comparison of the kinetic properties of 20 and 26 S proteasomes showed significant differences in the kinetic characteristics with certain substrates and differences in the effects of a protein substrate on peptidase activity. Observed differences in the kinetics of peptidylglutamyl peptide hydrolase activity suggest that the 26 S complex cannot undergo the conformational changes of 20 S proteasomes at high concentrations of the substrate benzyloxycarbonyl (Z) -Leu-Leu-Glu-b-naphthylamide. Various inhibitors that differentially affect the trypsin-like and chymotrypsin-like activities have been identified. Ala-Ala-Phe-chloromethyl (CH2Cl) inhibits chymotrypsin-like activity assayed with succinyl (Suc) -Leu-Leu-Val-Tyr-AMC, but surprisingly not hydrolysis of Ala-Ala-Phe-7-amido-4-methylcoumarin (AMC). Tyr-Gly-Arg-CH2Cl inhibits Suc-Leu-Leu-Val-Tyr-AMC hydrolysis as well as trypsinlike activity measured with t-butoxycarbonyl (Boc) -Leu-Ser-Thr-Arg-AMC, while Z-Phe-Gly-Tyr-diazomethyl (CHN2) was found to inhibit only the two chymotrypsin- like activities. Radiolabeled forms of peptidyl chloromethane and peptidyl diazomethane inhibitors, [3H]acetyl-Ala-Ala-Phe-CH2Cl, [3H]acetyland radioiodinated Tyr-Gly-Arg-CH2Cl, and Z-Phe-Gly- Tyr-(125I-CHN2), have been used to identify catalytic components associated with each of the three peptidase activities. In each case, incorporation of the label could be blocked by prior treatment of the proteasomes with known active site-directed inhibitors, calpain inhibitor 1 or 3,4-dichloroisocoumarin. Subunits of labeled proteasomes were separated either by reverse phase-HPLC and SDS-polyacrylamide gel electrophoresis or by twodimensional polyacrylamide gel electrophoresis followed by autoradiography/fluorography and immunoblotting with subunit-specific antibodies. In each case, label was found to be incorporated into subunits C7, MB1, and LMP7 but in different relative amounts depending on the inhibitor used, consistent with the observed effects on the different peptidase activities. The results strongly suggest a relationship between trypsin-like activity and chymotrypsin-like activity. They also help to relate the different subunits of the complex to the assayed multicatalytic endopeptidase activities