990 resultados para biomass resources
Resumo:
Qualitative and quantitative measurements of biomass components dissolved in the phosphonium ionic liquids (ILs), trihexyltetradecylphosphonium chloride ([P66614]Cl) and tributylmethylphosphonium methylsulphate ([P4441]MeSO 4), are obtained using attenuated total reflectance-FTIR. Absorption bands related to cellulose, hemicelluloses, and lignin dissolution monitored in situ in biomass-IL mixtures indicate lignin dissolution in both ILs and some holocellulose dissolution in the hydrophilic [P4441]MeSO 4. The kinetics of lignin dissolution reported here indicate that while dissolution in the hydrophobic IL [P66614]Cl appears to follow an accepted mechanism of acid catalyzed -aryl ether cleavage, dissolution in the hydrophilic IL [P4441]MeSO 4 does not appear to follow this mechanism and may not be followed by condensation reactions (initiated by reactive ketones). The measurement of lignin dissolution in phosphonium ILs based on absorbance at 1510 cm 1 has demonstrated utility. When coupled with the gravimetric Klason lignin method, ATR-FTIR study of reaction mixtures can lead to a better understanding of the delignification process. © 2012 Copyright Taylor and Francis Group, LLC.
Resumo:
The combined impact of social class, cultural background and experience upon early literacy achievement in the first year of schooling is among the most durable questions in educational research. Links have been established between social class and achievement but literacy involves complex social and cognitive practices that are not necessarily reflected in the connections that have been made. The complexity of relationships between social class, cultural background and experience, and their impact on early literacy achievement have received little research attention. Recent refinements of the broad terms of social class or socioeconomic status have questioned the established links between social class and achievement. Nevertheless, it remains difficult to move beyond deficit and mismatch models of explaining and understanding the underperformance of children from lower socioeconomic and cultural minority groups when conventional measures are used. The data from an Australian pilot study reported here add to the increasing evidence that income is not necessarily related directly to home literacy resources or to how those resources are used. Further, the data show that the level of print resources in the home may not be a good indicator of the level of use of those resources.
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The Commonwealth Department of Industry, Science and Resources is identifying best practice case study examples of supply chain management within the building and construction industry to illustrate the concepts, innovations and initiatives that are at work. The projects provide individual enterprises with examples of how to improve their performance, and the competitiveness of the industry as a whole.
Resumo:
Increased or fluctuating resources may facilitate opportunities for invasive exotic plants to dominate. This hypothesis does not, however, explain how invasive species succeed in regions characterized by low resource conditions or how these species persist in the lulls between high resource periods. We compare the growth of three co-occurring C4 perennial bunchgrasses under low resource conditions: an exotic grass, Eragrostis curvula (African lovegrass) and two native grasses, Themeda triandra and Eragrostis sororia. We grew each species over 12 weeks under low nutrients and three low water regimes differentiated by timing: continuous, pulsed, and mixed treatments (switched from continuous to pulsed and back to continuous). Over time, we measured germination rates, time to germination (first and second generations), height, root biomass, vegetative biomass, and reproductive biomass. Contrary to our expectations that the pulsed watering regime would favor the invader, water-supply treatments had little significant effect on plant growth. We did find inherent advantages in a suite of early colonization traits that likely favor African lovegrass over the natives including faster germination speed, earlier flowering times, faster growth rates and from 2 weeks onward it was taller. African lovegrass also showed similar growth allocation strategies to the native grasses in terms of biomass levels belowground, but produced more vegetative biomass than kangaroo grass. Overall our results suggest that even under low resource conditions invasive plant species like African lovegrass can grow similarly to native grasses, and for some key colonization traits, like germination rate, perform better than natives.
Resumo:
The presence of large number of single-phase distributed energy resources (DERs) can cause severe power quality problems in distribution networks. The DERs can be installed in random locations. This may cause the generation in a particular phase exceeds the load demand in that phase. Therefore the excess power in that phase will be fed back to the transmission network. To avoid this problem, the paper proposes the use of distribution static compensator (DSTATCOM) that needs to be connected at the first bus following a substation. When operated properly, the DSTATCOM can facilitate a set of balanced current flow from the substation, even when excess power is generated by DERs. The proposals are validated through extensive digital computer simulation studies using PSCAD and MATLAB.
Resumo:
This paper addresses the snap of renewable energy and the need for effective progress strategies linked with sustainable energy development along with prospect of renewable energy in Bangladesh. Our country is gifted with vast renewable energy resources such as biomass and solar. Approximately 73% of total energy demand of the country is supplied by local biomass based fuels. Bangladesh is endowed with abundant supplies of solar energy. Annually about 1.9 MWh energy is received per square meter of horizontal area in Bangladesh. Besides, hydro and wind as well as geothermal power can be considered as potential renewable energy resources. Karnafuli Hydro Station is the merely hydro energy power generation plant of the country that generates 230 MW. The annual wind speed at a height of 25m at some coastal locations is above 5 m/s and much higher in the pre-monsoon and monsoon periods.
Resumo:
Open Educational Resources (OER) are teaching, learning and research materials that have been released under an open licence that permits online access and re-use by others. The 2012 Paris OER Declaration encourages the open licensing of educational materials produced with public funds. Digital data and data sets produced as a result of scientific and non-scientific research are an increasingly important category of educational materials. This paper discusses the legal challenges presented when publicly funded research data is made available as OER, arising from intellectual property rights, confidentiality and information privacy laws, and the lack of a legal duty to ensure data quality. If these legal challenges are not understood, addressed and effectively managed, they may impede and restrict access to and re-use of research data. This paper identifies some of the legal challenges that need to be addressed and describes 10 proposed best practices which are recommended for adoption to so that publicly funded research data can be made available for access and re-use as OER.
Resumo:
This paper reports the findings of a qualitative study which investigated 25 international students’ use of online information resources for study purposes at two Australian universities. Using an expanded critical incident approach, the study viewed international students through an information literacy lens, as information-using learners. The findings are presented in two complementary parts: as a word picture that describes their whole experience of using online information resources to learn; and as a tabulated set of critical findings that summarises their associated information literacy learning needs. The word picture shows international students’ resource use as a complex interplay of eight inter-related elements: students; information-learning environment; interactions (with online resources); strengths-challenges; learning-help; affective responses; reflective responses; cultural-linguistic dimensions. In using online resources, the international students experience an array of strengths and challenges, and an apparent information literacy imbalance between their more developed information skills and less developed critical information use. The critical findings about information literacy needs provide a framework for developing an inclusive informed learning approach that responds to international students’ complex information using experiences and needs. While the study is situated in Australia, the findings are of potential interest to educators, information professionals and researchers worldwide who seek to support learning in culturally diverse higher education contexts.
Resumo:
BACKGROUND The work described in this paper has emerged from an ALTC/OLT funded project, Exploring Intercultural Competency in Engineering. The project indentified many facets of culture and intercultural competence that go beyond a culture-as-nationality paradigm. It was clear from this work that resources were needed to help engineering educators introduce students to the complex issues of culture as they relate to engineering practice. A set of learning modules focussing on intercultural competence in engineering practice were developed early on in the project. Through the OLT project, these modules have been expanded into a range of resources covering various aspects of culture in engineering. Supporting the resources, an eBook detailing the ins and outs of intercultural competency has also been developed to assist engineering educators to embed opportunities for students to develop skills in unpacking and managing cross-cultural challenges in engineering practice. PURPOSE This paper describes the key principles behind the development of the learning modules, the areas they cover and the eBook developed to support the modules. The paper is intended as an introduction to the approaches and resources and extends an invitation to the community to draw from, and contribute to this initial work. DESIGN/METHOD A key aim of this project was to go beyond the culture-as-nationality approach adopted in much of the work around intercultural competency (Deardorff, 2011). The eBook explores different dimensions of culture such as workplace culture, culture’s influence on engineering design, and culture in the classroom. The authors describe how these connect to industry practice and explore what they mean for engineering education. The packaged learning modules described here have been developed as a matrix of approaches moving from familiar known methods through complicated activities relying to some extent on expert knowledge. Some modules draw on the concept of ‘complex un-order’ as described in the ‘Cynefin domains’ proposed by Kurtz and Snowden (2003). RESULTS Several of the modules included in the eBook have already been trialled at a variety of institutions. Feedback from staff has been reassuringly positive so far. Further trials are planned for second semester 2012, and version 1 of the eBook and learning modules, Engineering Across Cultures, is due to be released in late October 2012. CONCLUSIONS The Engineering Across Cultures eBook and learning modules provide a useful and ready to employ resource to help educators tackle the complex issue of intercultural competency in engineering education. The book is by no means exhaustive, and nor are the modules, they instead provide an accessible, engineering specific guide to bringing cultural issues into the engineering classroom.