302 research outputs found
Surface modified composite nanofibers for the removal of indigo carmine dye from polluted water
Surface coated magnetite nanoparticles (Fe(3)O(4) NPs) with 3-mercaptopropionic acid were immobilized on amidoximated polyacrilonitrile (APAN) nanofibers using electrospinning followed by crosslinking. The prepared composite nanofibers were characterized with Scanning Electron Microscopy (SEM), and Fourier Transform Infrared analysis (FTIR). The composite nanofiber was evaluated for the removal of indigo carmine dye from aqueous solutions. The effects of contact time, initial dye concentration, solution pH and adsorption equilibrium isotherms were studied. The adsorption of indigo carmine was found to be greatly affected by solution pH. The maximum loading capacity was determined to be 154.5 mg g(â1) at pH = 5. The experimental kinetic data were fitted well using a pseudo-first order model. The adsorption isotherm studies showed that the adsorption of indigo carmine fits well with the Langmuir model. The reuse of the composite nanofiber was also investigated in which more than 90% of indigo carmine was recovered in 5 min. The results of stability studies showed that the adsorption efficiency can remain almost constant (90%) after five consecutive adsorption/desorption cycles
Effects of the current financial and economic crisis on the rural landscape as well as the agri-food sector in Europe and Central Asia
This paper reviews the expected effects of the current financial crisis and subsequent recession on the rural landscape, in particular the agri-food sector in Europe and Central Asia (ECA) on the basis of the structure of the rural economy and of different organisations and institutions. Empirical evidence suggests that the crisis has hit the ECA region the hardest. Agriculture contributes about 9% to gross domestic product (GDP) for the ECA region as a whole with 16% of the population being employed in the agricultural sector. As far as the impact of the financial crisis on the agri-food sector is concerned, there are a few interconnected issues: (1) reduction in income elastic food demand and commodity price decline, (2) loss of employment and earnings of rural people working in urban centres, implying also costly labour reallocation, (3) rising rural poverty originating mainly from lack of opportunities in the non-farm sector and a sizable decline of international remittances, (4) tightening of agricultural credit markets, and the (5) collapse of sectoral government support programs and social safety-net measures in many countries. The paper reveals how the crisis hit farming and broader agri-business differently in general and in the ECA sub-regions
The literacy practices for assessment in the vocational curriculum - the case of Hospitality
This article explores two case studies of the literacy practices of assessment in the vocational curriculum. Previous studies have identified learning in the vocational curriculum as being assessment-driven and that subjects often associated with limited levels of literacy actually require multiple literacy practices from students. Drawing upon studies of the literacy practices of assessment in the teaching of Hospitality, the study explores the academic and occupational forms of reading and writing required of students. These literacy practices are often invisible to both students and staff and yet are central to the success of students in relation to attainment. The article suggests that vocational subjects may actually be more demanding in the range of literacies required for assessment than is often considered to be the case
CONSCIENTIZAĂĂO CRĂTICA DA LINGUAGEM
The authors assume that the development of a critical awareness of the world ought to be the main objective of all education, including language education. Language awareness programmes ought therefore to help children develop not only operational and descriptive knowledge of the linguistic practices of their world, but also a critical awareness of how these practices are shaped by, and shape, social relationships and relationships of power.
In the first part of a two-part paper, the authors show that many existing language awareness proposals and materials are not âcriticalâ in this sense. On the contrary, with a few exceptions, they present the naturalised domain of linguistic practices as a natural domain, a given and common sense reality with social origins which are out of sight. This is true for bilingual, dialectal and diatypic variation. Most current approaches to language awareness present the domain of linguistic practices as a pluralistically harmonious domain; no attention is given to ideological differences or ideological struggles in language, and, in fact, the nexus of language-power-ideology is ignored. Despite their admirable attempts to heighten cross-cultural undertanding and harmony, they appear to underscore the legitimacy of the already legitimated set of existing linguistic practices, and therefore indirectly of the existing power relations which underpin these practices.
In the second part of the paper, they briefly explore the notion of Critical Language Analysis (or Critical Linguistics in a generic sense), and indicate how this approach might contribute to more critical Language Awareness programmes. The authors also argue that the diverse objectives which are usually given for Language Awareness programmes appear to be given particular desocialising weightings in actual materials, and suggest a way of articulating the various objectives that might be in agreement with a critical perspective. They end with an example of how Critical Language Awareness can be incorporated into a family history writing project
How Strong Do Global Commodity Prices Influence Domestic Food Prices in Developing Countries? A Global Price Transmission and Vulnerability Mapping Analysis
This paper analyzes the transmission from global commodity to domestic food prices for a large set of countries. First, a theoretical model is developed to explain price transmission for different trade regimes. Drawing from the competitive storage model under rational expectations, it is shown that domestic prices can respond instantaneously to global prices even if no trade takes place but future trade is expected. Using a global database on food prices, we construct national and international grain price indices. With an autoregressive distributed lag model, we empirically detect countries in which food prices are influenced by global commodity prices, including futures prices. Mapping transmission elasticities with the size of the population below the poverty line which spends typically a large share of its income on food, we are able to estimate the size of vulnerable population. Our empirical analysis reveals that 90 percent of the global poor (income below 1.25$/day) live in countries where domestic food prices respond to international prices - but the extent of transmission varies substantially. For 360 million poor people, international prices transmit to their country at rates of 30 percent or higher within three months
Ab-Initio Calculation of Molecular Aggregation Effects: a Coumarin-343 Case Study
We present time-dependent density functional theory (TDDFT) calculations for
single and dimerized Coumarin-343 molecules in order to investigate the quantum
mechanical effects of chromophore aggregation in extended systems designed to
function as a new generation of sensors and light-harvesting devices. Using the
single-chromophore results, we describe the construction of effective
Hamiltonians to predict the excitonic properties of aggregate systems. We
compare the electronic coupling properties predicted by such effective
Hamiltonians to those obtained from TDDFT calculations of dimers, and to the
coupling predicted by the transition density cube (TDC) method. We determine
the accuracy of the dipole-dipole approximation and TDC with respect to the
separation distance and orientation of the dimers. In particular, we
investigate the effects of including Coulomb coupling terms ignored in the
typical tight-binding effective Hamiltonian. We also examine effects of orbital
relaxation which cannot be captured by either of these models
The Recruitment Agent in Internationalized Higher Education: Commercial Broker and Cultural Mediator
The internationalization and marketization of higher education has resulted in U.K. universitiesâ increasing reliance on recruitment agents to boost international student numbers. This places agents and agencies in a position of considerable influence with regard to the educational choices that students make. These institutional and individual relationships have been investigated from a marketing perspective, contributing knowledge about the influence of recruitment agents on student decision making. However, this approach has limitations with regard to understanding the impact of agents on an international studentâs subsequent experience in U.K. higher education. The article suggests that theoretical work on mobility, migration, and ethnographies of communication, including the geopolitics of text production, can provide useful lenses for analyzing how agents help international students navigate the journey into and through U.K. higher education. The notion of âcultural mediatorâ is introduced to analyze the role played by agents alongside that of commercial broker. We argue that future research, shaped by these alternative theoretical perspectives, may help to bridge the apparent gap in understanding between those working in international offices and those involved in teaching in an internationalized university
Making visible âhiddenâ intentions and potential choices: international students in intercultural communication
The study reported in this paper examines the experiences of Chinese and Vietnamese international students in engaging in their institutional written discourse at an Australian university. The study highlights the significance of exploring the real accounts of the students as the ‘insiders’ and uncovering students’ individual potential choices and intentions as their ‘seemingly unrecognized’ values in producing their own texts in English as a second language. In particular, based on international students’ reflection on their intentions and potential choices in academic practices, the study signals how the taken-for-granted institutional conventions may contribute to silencing or marginalizing the possibilities for alternative approaches to knowledge and communication within the higher education institutional context
Developing a Theoretical Framework for Response: Creative Writing as Response in the Year 6 Primary Classroom
Focusing on the creative writing of Year 6 boys as they make the transition to Year 7, this article establishes a theoretical model for creative writing as response. In line with Bakhtinâs notion of utterances as âinterpersonalâ (1986), the model demonstrates the complexity of creative writing â the text is influencing of and influenced by an authorâs participation in âfigured worldsâ (Holland, Lachicotte, Skinner and Cain 1998), but also influencing of and influenced by future respondents. This article suggests that âweaker framingâ (Bernstein 2000) in creative writing pedagogy has the potential to alter boysâ identities and refigure their worlds
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