Impact of water saving irrigation systems on water use, growth and yield of irrigated lowland rice

To meet the growing demand for food and other needs from an increasing population, the rice production in Sri Lanka, which was 3.87 million tonnes in 2008, has to be increased to 4.2 million tonnes by the year 2020. This requirement could be achieved by increasing productivity and/or by increasing the cultivated extent. In 2008, about 77 % and 68 % of the total paddy land extent was cultivated with either partial or full irrigation during the maha and yala seasons, respectively. A considerable extent of paddy land was either not cultivated or cultivated for other crops due to the scarcity of water in the dry and intermediate zones. Furthermore, with increased competition for water for domestic and industrial needs and climate change, there will be further reductions in the availability of water for rice cultivation. Conserving irrigation water would increase the cultivated extent of land while reducing the probability of ate season water-stress in the cultivated rice crop. We studied the impact of different soil water regimes on water use, nutrient uptake, growth and grain yield of 3 – 3� age lowland rice at the Rice Research and Development Institute, Batalagoda, Ibbagamuwa. There was no significant difference in the grain yield in rice when grown under either saturated or flooded conditions, but the yield decreased significantly with alternate wetting and drying. However, under saturated conditions, the irrigation water requirement was significantly lower than the flooded condition. The lowest irrigation water requirement was recorded with saturated to dry conditions. The irrigation water requirement under flooded conditions, when compared with the saturated condition, increased by 39 % during the yala season. During the maha season, even though the total irrigation requirement was lower, when compared to saturated conditions, four times more irrigation water was required under flooded conditions. There was a significant increase in plant dry matter production and leaf N (nitrogen) under saturated conditions, when compared with conventional flooded conditions. These findings suggest that when soil water is maintained at a saturated level in lowland rice, a considerable amount of irrigation water could be saved without sacrificing grain yield.Length: pp.57-64RiceIrrigated farmingWater conservationIrrigation systems

Comparison of Delay Distributions of Responses in a Home Area Network using Wi-Fi with and without in-network Data Aggregation

Smart Grid is divided into seven sub domains by NIST. The customer domain refers to the end users of electricity. In addition to the traditional role of consumer, they will also participate in generation as well as storage of energy. They would respond to signals coming from the grid and reduce or increase consumption and/or generation accordingly. For this purpose the customer premise should be equipped with an information network, which is called a Home Area Network. Architecture of a Home Area Network needs to be optimised in terms of time and energy. In this research the behaviour of a HAN in terms of time is studied. Delays of responses from the devices for the requests made by the central controller were measured for two most popular architectures, with and without in-network data aggregation. When the probability mass functions were plotted, it was evident that the delays in the two cases do not differ by much

Sustainable Housing for Middle-Income Society in Sri Lanka

Housing is a fundamental human necessity and affects how society interacts with the environment. In the modern era, housing expansions all over the world have significantly increased the number of economic, social, and environmental issues. Making housing constructions in places that are quickly urbanizing more sustainable is a top objective for government agencies, business experts, and research organizations. Managing economic, environmental, and social sustainability factors is referred to as sustainable housing. Major natural resources used in the construction of housing include land, energy, water, and building materials. Minor natural resources used in the process include waste production and air and water pollution. In the community's fight for affordable housing, educated middle-income inhabitants are predicted to be the most susceptible group given expected living standards and monthly income-generating levels. The goals are to explain how the framework for evaluating laws was developed and proven to be valid in order to achieve sustainability in middle-income housing. In order to offer the essential background for developing an interim assessment framework for affordable and sustainable middle-income housing, the research begins by analyzing the current local assessment frameworks and regulations. To evaluate the interim assessment framework, a semi-structured questionnaire survey of business professionals and other stakeholders will serve as the foundation for the secondary study. This intermediate evaluation framework will receive the necessary fine-tuning and industry feedback through discussion and opinions. The interim framework must be transformed into a robust and progressive regulatory structure that enables future success in SH for the majority of middle-class citizens in the nation. The results will next be evaluated in light of Sri Lanka's existing regulatory framework for sustainable middle-income housing. © 2022 The Authors. Published by Department of Estate Management and Valuation, University of Sri Jayewardenepura   Keywords: Sustainable Housing, Middle-income Society, Housing Crisi

Current distribution and abundance of slender lorises (Loris tardigradus and L. Iydekkerianus) in Sri Lanka

Two species of slender lorises are currently recognized in Sri Lanka. They are Sri Lanka red slenderloris (Loris tardigradusj and Grey slender loris (L. lydekkerianus i, with four currently recognizedsub-species; viz. Western red slender loris (L. t. tardigradus), Montane slender loris (L. t.nycticeboidesi, Northern grey slender loris (L. 1.nordicusi, and Highland slender loris (L. 1.grandis).The objective of this survey was to map the distribution and estimate the abundance of lorises in SriLanka. The study was initiated in 2002 and continues to date. Thus far forty-five sites across all ofthe ecological zones have been surveyed covering approximately 400 krn-. In six of these sites, loriseswere not recorded. Of the other 39 sites, 223 sightings of slender loris (L. t. tardigradus (n = 86), L.t. nycticeboides (n = 3), L. 1. nordicus (n = 122), and L. l. grandis (n = 12). Abundance estimates, 'base on sightings of animals krn', were: L. t. tardigradus (0.5-8), L. t. nycticeboides (0.03), L. I.nordicus (0.7-13). and L. 1. grandis (0.3-4) were recorded. The abundance of lorises varied indifferent habitat types with the highest abundance oflorises occurring in the dry zone monsoon forests.The least abundance of lorises was recorded in the cloud forest

A comparison of erect weight-bearing and non-weight-bearing radiography of the cervical spine in non-trauma patients

Introduction: Various positioning techniques are utilized to enhance the visualization of lower cervical vertebrae on lateral radiographs. However, the effectiveness of these techniques still remains unclear. This study was conducted to determine the effect of the weight-bearing (WB) technique in visualizing lower cervical vertebrae and cervicothoracic junction (C7-T1) on standing lateral cervical radiographs of adult non-trauma patients. The study was conducted using both computed radiography (CR) and digital radiography (DR) systems. Methods: Forty-four CR (29 WB and 15 non-WB – NWB) and 61 DR (26 WB and 35 NWB) lateral C-spine radiographs were prospectively evaluated to assess the visible number of cervical vertebral bodies and C7-T1 junction. The instructions given by the radiographer to the patient for the imaging procedure were also assessed on the Likert scale (very good, good, fair, poor, very poor). Results: There was no significant difference (p > 0.05) in the visualization of the number of vertebral bodies between the two techniques of WB and NWB for CR or DR. Further, no significant relationship (p > 0.05) was observed between the WB technique and the visualization of C7-T1 junction in DR systems. However, a significant difference was identified for CR (p = 0.012). The instruction given to the patient significantly correlated with the visibility of the lower C-spine region within each group of WB and NWB in both imaging systems. Conclusions: The visibility of the number of vertebral bodies in the lower C-spine region in either CR or DR systems did not demonstrate any enhancement with the WB technique. Regardless of the imaging system or techniques used, adequate instructions given to the patient before and during the imaging procedure of C-spine lateral radiography demonstrated a significant improvement in visualizing the lower C-spine region. In this preliminary study, the application of erect WB radiography technique in evaluating the lower cervical region of adult non-trauma patients gives limited advantage

Estimation of drag coefficient of trees considering the tree bending or overturning situations

Drag coefficients of a real tree trunk and the sheltering effects of an upstream trunk on a downstream one in a linear arrangement with different spacings and inclinations were investigated in detail. In addition, for elucidating the change of drag coefficient for an overturned tree, drag force acting on a real tree with roots was also measured in this study. For the measurement of drag force with different inclinations, Terminalia Cattapa and Albizia sp., vegetated in Sri Lanka, were selected in this study. Drag coefficient of inclined tree trunk has the similar tendency in relation to the Reynolds number with that of vertical standing tree investigated in Tanaka et al.(2011). For the vertical tree trunk with rough surface, drag coefficient of rear-side tree trunk was decreased with decreasing L/d (where, L is spacing and d is the diameter of trunk). In addition, as a result of mutual interference experiment of two inclined tree trunk, the drag coefficient of rear-side trunk decreased with the increase of the inclination. Under the influence of the increment of projected area due to existence of roots and shear force acting on tree trunk surface, the drag coefficient of a tree with roots became similar value (1.0-1.2) comparing with that of a vertical standing tree

Analysis of drag force characteristics of real trees with three different types of vegetation for bioshield in coast

This paper presents the experimental investigations on drag force characteristics of vegetation in mitigating the impact of tsunami and other surge effects by the resistance offered to the flow. The experiment was conducted in a laboratory towing tank of 50m x 2m x 2m. Three types of vegetation species used were the trees with small thin broad leaves (Wetakeyya), large broad leaves (Kottamba) and stick type leaves (Kasa). The drag force characteristics of the vegetations mainly depend on the differences in the distribution of foliation, different streamlining mechanism of the leaves against flow, the roughness and the shape of the tree trunk. Drag coefficient of vegetation varies with the flow velocity; the lower flow velocities show higher drag coefficients because of the maximum frontal projected area of the plant. The drag coefficients for the canopies show higher values for the Reynolds numbers less than 106. For canopies with large broad leaves (Kottamba), it ranges from 0.02 to 0.2. The drag coefficients for small thin broad leaves (Wetakeyya) and stick type leaves (Kasa) range from 0.1 to 1.7 and 0.18 to 0.7. Comparatively the drag coefficient of Wetakeyya is greater than Kottamba and Kasa at larger Reynolds numbers (Re > 106). Previous studies on vegetal drag are mainly focused on the single rigid cylinders and colony of rigid cylinders. The studies with single rigid cylinders show an almost linear relationship between drag force and square of the mean velocity of flow. However, the limited studies with natural flexible vegetation show a linear relationship between drag force and mean velocity. Drag coefficient for the trunks of above three types of trees were found less than the smooth cylinder for the region of Re > 60000. For this region the drag coefficient for Kasa trunk ranged in between 0.9 to 1.0 while for the smooth PVC pipe it ranged in between 1.2 – 1.4. For Kottamba it was in between 0.8 – 0.9 and for Wetakeyya it was around 0.6

Relation between Sectoral Distribution of Commercial Bank Credit and Economic Growth in Sri Lanka

This study investigates the impact of sectoral distribution of commercial bank credit on economic growth in Sri Lanka based on data from 2005 to 2017. The Auto-regressive Distributed Lag (ARDL) model is used to investigate short and long run impact of sectoral distribution of commercial bank credit on Gross Domestic Product (GDP). The findings of the ARDL Error Correction model indicate that the commercial bank sectoral credit distribution is significantly explaining the short run economic growth. Moreover, ARDL long run form and bounds test shows that there is a long run relation between the variables. The industrial sector has a long run positive relationship with GDP while the other sectors are insignificant in explaining long run economic growth. According to the results, the government can motivate banks to distribute credit facilities to the industry sector to boost GDP in the long-run. This is the first study that discusses the sectoral distribution of commercial bank credit on economic growth of Sri Lanka as per the best of the authors‟ knowledge. Keywords Commercial bank, Credit, Economic growth, Gross Domestic Produc

Towards Digital Thinking and Practices: Experiences of Sri Lankan Teachers and Students

Commonwealth Digital Education Leadership Training in Action (C-DELTA), an open and free online programme of the Commonwealth of Learning, provides a framework to foster digital education. The Open University of Sri Lanka implemented an intervention during 2020-2021 to promote digital education in Sri Lankan secondary schools, through the adoption of C-DELTA. This paper presents how C-DELTA supported developing digital thinking and practices among teachers and students, challenges faced and supports received by them, and impacts of the intervention. Participants’ experiences were captured through questionnaire surveys, concept maps, focus group interviews, reflective stories, and video narratives. The findings revealed that the intervention has enhanced developing digital learning skills of teachers and students, and changing their thinking and practices, yet, amid various challenges. While the implementation of C-DELTA in schools has been slow during the COVID-19 pandemic, the pandemic itself has shown the significance of improving digital literacy and digital practices

Histopathological diagnosis of myocarditis in a dengue outbreak in Sri Lanka, 2009

<p>Abstract</p> <p>Background</p> <p>In 2009, an outbreak of dengue caused high fatality in Sri Lanka. We conducted 5 autopsies of clinically suspected myocarditis cases at the General Hospital, Peradeniya to describe the histopathology of the heart and other organs.</p> <p>Methods</p> <p>The diagnosis of dengue was confirmed with specific IgM and IgG ELISA, HAI and RT-PCR techniques. The histology was done in tissue sections stained with hematoxylin and eosin.</p> <p>Results</p> <p>Of the 319 cases of dengue fever, 166(52%) had severe infection. Of them, 149 patients (90%) had secondary dengue infection and in 5 patients, DEN-1 was identified as the causative serotype. The clinical diagnosis of myocarditis was considered in 45(27%) patients. The autopsies were done in 5 patients who succumbed to shock (3 females and 2 males) aged 13- 31 years. All had pleural effusions, ascites, bleeding patches in tissue planes and histological evidence of myocarditis. The main histological findings of the heart were interstitial oedema with inflammatory cell infiltration and necrosis of myocardial fibers. One patient had pericarditis. The concurrent pulmonary abnormalities were septal congestion, pulmonary haemorrhage and diffuse alveolar damage; one case showed massive necrosis of liver.</p> <p>Conclusions</p> <p>The histology supports occurrence of myocarditis in dengue infection.</p