197 research outputs found

    Environmental Preferences of Yellowfin Tuna in the North East Indian Ocean: An Application of Satellite Data to Longline Catches

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    Abstract: Development of state-of-the-art methodologies to minimise search time and to increase the fishing efficiency of high seas fishery are vital for fishing success. It, minimise the operational cost as well as fishing duration that save the fish quality. Understanding of the ocean environment and their preferences of Yellowfin Tuna (YFT) are important aspect to addresses the fishing uncertainty thereby ensuring the expected catch during a short period of time. Environmental parameters such as temperature, chlorophyll and dynamic height of the sea surface were obtained from remote sensing satellites and a YFT catch dataset was obtained from Sri Lankan longliners. The results of the data analyses have shown that the relationships between oceanographic parameters and YFT catch rates were found significant. These relations are capable of predicting fishable aggregations of YFT using near-real time satellite observations. High frequencies of YFT catches were found in the areas where Sea Surface Temperature (SST) varied primarily between 28-30C. The corresponding Sea Surface Heights (SSH) ranged from 205-215 cm and Sea Surface Clorophyll_a (SSC) concentration ranged from 0.1-0.4 mg/m 3 . The relationships between catch rates and the three environmental variables have been tested with the Empirical Cumulative Distribution Function (ECDF). The degrees of differences between the ECDF and catch-weighted cumulative distributions of the three variables are statistically significant (p<0.01). The strongest association showed between catch rates and SSC while SSH showed the lowest. The results obtained from a Generalized Additive Model (GAM) have shown that the space-time factor is well above the ocean environmental factors and the oceanographic factors are also in significant levels (p<0.05). Therefore, the migratory pathway is an essential factor in predicting YFT inhabitants in the northeast Indian Ocean

    Trigeneration - a green approach for meeting total building service requirement

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    Tourism industry in the country is presently seeing a considerable growth, with demand for hotel and accommodation industry to keep pace. In expanding this sector, provision of electricity and other utilities is essential. In this regard, the availability of electricity supply and the quality of available power are serious concerns when it comes to expanding the facility to remote but attractive areas. As a means of handling this situation, in this paper the possibility of using stand alone trigeneration to meet, cooling and electricity demand of such facilities is explored and compared with the present system of grid connected power and diesel based heat generation. A comparison of the two systems; trigeneration and present base case scenario, reveals that there will be over 50% reduction in CO2 emission and about 41% saving in energy bills over those of base case when a trigeneration system is sized based on the criterion of meeting total cooling demand using vapour absorption refrigeration. A simple payback estimates shows that recovery of investment for trigeneration system is well under two years

    Problems Faced by Preschool Teachers When Using Teaching Aids in the Teaching Learning Process

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    This study attempts to find out the problems faced by the preschool teachers when making and using teaching aids in the process of teaching and learning, and to identify their perception on using teaching aids. The study employed quantitative method of research. The sample of this study comprised of 60 Sinhala mediumpreschool teachers and 40 English medium teachers who have registered in the Diploma in Early Childhood & Primary Education programme in the Colombo regional center, at OUSL. The study employed the survey research design. A questionnaire was adopted to collect data. The data were analyzed using simple quantitative statistical methods. The study revealed that the teacher have precise perception of teaching aids and its functions. However they face problems such as lack of time for making teaching aids for each lesson, lack of training on using electronic teaching aids, lack of knowledge on relating teaching aids to the lesson in the teaching learning process. Thus, the study recommends enhancing more emphasis by providing awareness, knowledge on using teaching aids effectively among preschool teachers.KEYWORDS: Teaching Aids, Preschool teachers, Teaching learning process, Perception, Problemfaced by preschool teache

    Involvement of alcohol in injury cases in rural Sri Lanka:Prevalence and associated factors among in-patients in three primary care hospitals

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    BACKGROUND: Injuries account for a major proportion of global morbidity and mortality related to alcohol use. Information on the prevalence of alcohol-related injury in rural Sri Lanka is limited. The aims of this study were to determine the burden of alcohol-related injury in a hospital-based sample in rural Sri Lanka and explore factors associated with an increased risk of alcohol-related injury. METHODS: Involvement of alcohol in injury amongst in-patients was assessed in three hospitals in the North Central Province of Sri Lanka over 6 months. Adult (≄ 18 years) patients were eligible. Patients were assessed for: injury characteristics, current alcohol use (in the past year) using the Alcohol Use Disorder Identification Test (AUDIT), and acute intoxication. Patients with a blood alcohol concentration (BAC) reading equivalent of 10 mg/dL (2.17 mmol/L) were considered as having an alcohol-related injury. Binary logistic regression was used to explore association between alcohol-related injury and demographic and injury characteristics. RESULTS: A total of 883 injured patients were eligible and consented to the study. No alcohol use was reported by 487 (55.2%) of patients (35.6% of men, 95.2% of women). Prevalence of alcohol-related injuries was 14.8% overall and 32.8% among current alcohol users. Almost all patients with an alcohol-related injury were male (122/123; 99.2%); 24 (18.8%) of these patients scored positive for possible alcohol dependence. Patients with an alcohol-related injury had significantly higher AUDIT scores (median = 15 vs 6, p < 0.001), were significantly more likely to be aged 26–40 (OR 2.29, 95% CI:1.11, 4.72) or 41–55 years (OR 2.76, 95% CI: 1.29, 5.90) (compared to 18–25 years), to have a transport-related injury (OR 5.14, 95% CI: 2.30, 11.49) (compared to animal/plant sting/bite), and have intentional injuries (OR 3.47, 95% CI: 1.01, 11.87). CONCLUSIONS: One in three injuries among people who drank alcohol in this sample were alcohol-related. In addition, problematic alcohol use was higher among those with alcohol-related injury. Further work is needed to explore whether this prevalence of alcohol-related injury is reflected in other rural settings in Sri Lanka. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-12958-8

    Comparative Toxicity of Nanoparticulate CuO and ZnO to Soil Bacterial Communities

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    The increasing industrial application of metal oxide Engineered Nano-Particles (ENPs) is likely to increase their environmental release to soils. While the potential of metal oxide ENPs as environmental toxicants has been shown, lack of suitable control treatments have compromised the power of many previous assessments. We evaluated the ecotoxicity of ENP (nano) forms of Zn and Cu oxides in two different soils by measuring their ability to inhibit bacterial growth. We could show a direct acute toxicity of nano-CuO acting on soil bacteria while the macroparticulate (bulk) form of CuO was not toxic. In comparison, CuSO4 was more toxic than either oxide form. Unlike Cu, all forms of Zn were toxic to soil bacteria, and the bulk-ZnO was more toxic than the nano-ZnO. The ZnSO4 addition was not consistently more toxic than the oxide forms. Consistently, we found a tight link between the dissolved concentration of metal in solution and the inhibition of bacterial growth. The inconsistent toxicological response between soils could be explained by different resulting concentrations of metals in soil solution. Our findings suggested that the principal mechanism of toxicity was dissolution of metal oxides and sulphates into a metal ion form known to be highly toxic to bacteria, and not a direct effect of nano-sized particles acting on bacteria. We propose that integrated efforts toward directly assessing bioavailable metal concentrations are more valuable than spending resources to reassess ecotoxicology of ENPs separately from general metal toxicity

    Evaluating biochar and its modifications for the removal of ammonium, nitrate, and phosphate in water

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    Removal of nitrogen (N) and phosphorus (P) from water through the use of various sorbents is often considered an economically viable way for supplementing conventional methods. Biochar has been widely studied for its potential adsorption capabilities for soluble N and P, but the performance of different types of biochars can vary widely. In this review, we summarized the adsorption capacities of biochars in removing N (NH4-N and NO3-N) and P (PO4-P) based on the reported data, and discussed the possible mechanisms and influencing factors. In general, the NH4-N adsorption capacity of unmodified biochars is relatively low, at levels of less than 20 mg/g. This adsorption is mainly via ion exchange and/or interactions with oxygen-containing functional groups on biochar surfaces. The affinity is even lower for NO3-N, because of electrostatic repulsion by negatively charged biochar surfaces. Precipitation of PO4-P by metals/metal oxides in biochar is the primary mechanism for PO4-P removal. Biochars modified by metals have a significantly higher capacity to remove NH4-N, NO3-N, and PO4-P than unmodified biochar, due to the change in surface charge and the increase in metal oxides on the biochar surface. Ambient conditions in the aqueous phase, including temperature, pH, and co-existing ions, can significantly alter the adsorption of N and P by biochars, indicating the importance of optimal processing parameters for N and P removal. However, the release of endogenous N and P from biochar to water can impede its performance, and the presence of competing ions in water poses practical challenges for the use of biochar for nutrient removal. This review demonstrates that progress is needed to improve the performance of biochars and overcome challenges before the widespread field application of biochar for N and P removal is realized

    Biochar composites: Emerging trends, field successes, and sustainability implications

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