39,006 research outputs found

    The impact of inappropriate soil management on river water quality: a case study in the Kurundu Oya Sub-catchment of the Upper Mahaweli Catchment, Sri Lanka

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    The results of many studies have revealed that intensive farming on steep slopes, coupled with over application of fertilizers and accumulation of nutrients in downstream water bodies due to soil erosion, have contributed to environmental hazards in the Upper Mahaweli Catchment Area (UMCA) of Sri Lanka. The encroachment of riparian zones for exotic vegetable cultivation has aggravated this situation. In view of this, a study was conducted in the Kurundu Oya catchment, a micro-catchment of the UMCA, to investigate the soil management practices within the farming systems and their impacts on river water quality. Three villages were selected along the Kurundu Oya: Mahakudugala, Kumbalgamuwa and Batagolla. The study consisted of a survey of 150 households in 2007 and 2008, to gather information on the characteristics of householders and on soil management practices. A soil survey was carried out to analyze the soil fertility of farmlands. Water quality parameters were measured periodically in different sections of a selected stream. The results revealed that nearly 50 % of the riparian zones in the upper catchment of the Kurundu Oya stream are encroached to cultivate potato and other exotic vegetables. In addition, it was observed that over application of fertilizers on the vegetable plots was causing nutrient accumulation and the plots also recorded high levels of phosphorous (P) (above 75 ppm). Results of the water quality analysis showed that nitrate and available P levels were within the standard limits, but nitrate nitrogen (NO3-N) levels were close to the upper level of the standard limit. Therefore, in order to minimize water pollution, it is strongly recommended that fertilizer application is based on soil tests. In addition, encroachment of sensitive lands has to be addressed. Priority should be given to strengthening institutional capacity in order to facilitate the implementation of existing environmental legislation.Length: pp.49-60Soil managementSoil degradationCatchment areasErosionSedimentationWater pollutionFertilizer applicationNitrogenVegetable growing

    Dynamically generated dimension reduction and crossover in a spin orbital model

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    We study a spin orbital model in which the spin-spin interaction couples linearly to the orbital isospin. Fluctuations drive the transition from paramagnetic state to C type ordered state into a strongly first order one, as observed in V2O3V_2O_3. At T=0, there is a FOCS to FOGS transition. Close to the transition point, the system shows dynamically generated dimension reduction and crossover, resulting in one or more spin reentrant transitions.Comment: Submitted to PRL. 4 pages and one figur

    Household water security through stored rainwater and consumer acceptability: a case study of the Anuradhapura District

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    Rainwater harvesting has increased in popularity in Sri Lanka over the past two decades due to the number of water supply projects funded by the government and non-governmental organizations (NGOs). The stored rainwater can provide accessible, reliable, timely and adequate supplies of water to households but there are uncertainties as to safety, in terms of water quality, and consumer acceptability. A study was, therefore, conducted in the Anuradhapura District, in the dry zone, to assess consumer acceptability of stored rainwater for household purposes and to conduct rainwater quality tests in a laboratory. The majority of households in Anuradhapura meet their drinking water requirements from protected wells (59.6 %). Prior to the project, people greatly preferred open wells as a source of domestic water, followed by tubewells, because they believed that water in open wells is of good quality and drinkable. However, stored rainwater has become the priority source now, especially through roof rainwater harvesting (RRWH), which is used during the dry periods. The study revealed that more than 85 % of households use stored rainwater for drinking although some have concerns over the quality and only drink it after boiling. The easy accessibility of water and the assurance by the project team that it is of good quality are the main reasons that people are willing to drink it. The acceptability of stored rainwater for consumption was very high in water-scarce areas and with the increasing distance to the nearest and alternative sources of good-quality water. Of those who felt that they had adequate water, 84 % of the sample households found it adequate in the wet season but only 21 % in the dry season. Water quality analysis revealed that the chemical and physical quality of stored rainwater is within the acceptable range with respect to Sri Lankan Standards, SLS: 614, for potable water quality (SLIS 1983). Other domestic water sources exceeded standards for electrical conductivity, total alkalinity, hardness, ammonium nitrogen, fluorides and total iron. However, stored rainwater was of lower biological quality than other domestic water sources.Length: pp.87-97Domestic waterWater securityWater harvestingWater qualityRural areasCase studies

    Progression and assessment in foreign languages at Key Stage 2

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    The teaching of primary languages has been increasing steadily, in response to the future entitlement for all Key Stage 2 (KS2) pupils aged 7-11 to learn a foreign language by 2010. However, there remain concerns about progression both within KS2 and through to secondary school and about how learners' progress is assessed. This paper presents findings on the issues of progression and assessment taken from case studies which formed part of a project funded by the then Department for Education and Skills (DfES), now the Department for Children, Schools and Families (DCSF). This project set out to evaluate 19 local authority (LA) Pathfinders in England that were piloting the introduction of foreign language learning at KS2 between 2003 and 2005. Findings revealed that there was inconsistency between schools, even within each LA Pathfinder, in the use of schemes of work and that assessment was generally underdeveloped in the majority of the Pathfinders. In order to set these findings in context, this paper examines the issues of progression and assessment in foreign language learning in England. Finally, it investigates the challenges English primary schools face in terms of progression and assessment in the light of the new entitlement and discusses implications for the future. Managing progression, both within KS2 and through to secondary school at KS3 (ages 11-14), is one of the key factors in determining the overall success of starting languages in primary school

    Electromagnetic properties of the Delta(1232) and decuplet baryons in the self-consistent SU(3) chiral quark-soliton model

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    We examine the electromagnetic properties of the Delta(1232) resonance within the self-consistent chiral quark-soliton model. In particular we present the Delta form factors of the vector-current GE0, GE2 and GM1 for a momentum-transfer range of Q21GeV2Q^{2} \leq 1GeV^{2}. We apply the symmetry-conserving quantization of the soliton and take 1/N_c rotational corrections into account. Values for the magnetic moments of all decuplet baryons as well as for the N-Delta transition are given. Special interest is also given to the electric quadrupole moment of the Delta.Comment: 24 pages, 8 figure

    Production, breeding and potential of cowpea crop in Brazil.

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    About 50 years ago cowpea was reported as a relatively minor tropical legume. However, in the last years, it has been emerging as one of the most important food legume of the 21st century (SINGH, 2010). Brazil is not out of this panorama. Brazilian agriculture is undergoing major technological changes and, in addition, globalization in agribusiness has caused impacts on the production chain of several crops, particularly those heavily dependent on the use of a large volume of agricultural inputs, mainly fertilizers and pesticides. Such crops have had a higher production cost each year. On the other hand, this situation has brought new opportunities. Business farmers have sought new alternatives for their production arrangements. In this context cowpea constitutes one of the best options.bitstream/item/85620/1/Doc-216-Production.pd

    Divergência genética em feijão-fava.

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    Objetivou-se estimar a divergência genética entre 49 populações de feijão-fava do Banco Ativo de Germoplasma da UFPI e os coeficientes de correlação fenotípica entre os seguintes caracteres morfoagronômicos : número de dias para o florescimento, número de dias até a maturação, número de vagens por planta, comprimento da vagem, largura da vagem, espessura da vagem, número de lócus por vagem, número de sementes por vagem, peso de cem sementes e produção de grãos por planta. O delineamento utilizado foi látice simples 7x7. Os caracteres número de vagens por planta, comprimento médio da vagem e largura da vagem apresentaram correlação alta e positiva com a produção de grãos. Na análise de agrupamento pelo método da distância média entre os grupos foram gerados quatro grupos, sendo que os genótipos UFPI-667 e UFPI-674 ficaram isolados em grupos distintos. Isso indica que esses genótipos são divergentes entre si e em relação aos demais, podendo assim, serem usados como genitores na formação de população segregante
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