47 research outputs found

    Increase the Turbidity Removal Efficiency in Raw Water Using Different Coagulation Process in Drinking Water Treatment: A Case Study in Water Treatment Plant of Kandana

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    Coagulation process is a most important part in the water treatment process. However, in the process of water treatment in water treatment plant Kandana, there is a problem on coagulation under higher and lower levels of turbidity using only Alum (Al2(SO4)3.14 H2O). This research study was conducted to improve coagulation process to increase the turbidity removal efficiency under higher (>80) and lower (<8) turbidity conditions. Therefore, the objectives of the study are, to study the proper coagulation process for low and very high turbidity levels in source water under the efficiency of Alum with anionic polymers (Polyacrylamide) and to study the efficiency of Alum with pre-lime (Calcium hydroxide) usage in the coagulation process. Water samples were collected from the intake when the turbidity level was high and low and sample size was 50 L per once. The average optimum Alum dose of the low turbidity levels was determined by conducting jar tests. Optimum Alum dose of the low turbidities was used to determine the optimum lime dose and the effective polymer adding method and the optimum polymer dose for the low turbidities. Chemical and physical parameters were tested for raw water samples and settled water samples. Above same procedure was conducted for the high turbidity samples. As conclusions, there was not a considerable difference of final turbidity among the addition of Alum only, addition of pre-lime with Alum and addition of polymer with Alum for low turbidity raw water. Therefore, adding polymer and pre-lime with Alum have not given an efficiency for the low turbidity raw water. According to the results of high turbidity raw waters there was a considerable difference of final turbidity among the addition of Alum only, addition of pre-lime and Alum and addition of polymer and Alum. Adding polymer and pre-lime with Alum is effective for high turbidity raw water. Adding polymers with Alum more effective than the adding pre-lime with Alum for high turbidity raw water. There was a considerable pH deference by lime and polymer coagulation in high turbidity raw water.Keywords: Turbidity, Raw water, Coagulation, Treatment, Jar tes

    Evidence for a critical leopard conservation stronghold from a large protected landscape on the island of Sri Lanka

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    The decline and extirpation of large carnivore populations can lead to cascading effects in natural ecosystems. An understanding of large carnivore population densities, distribution and dynamics is therefore critical for developing effective conservation strategies across landscapes. This is particularly important in island environments where species face increased extinction risk due to genetic isolation coupled with local losses of finite habitat. The Sri Lankan leopard Panthera pardus kotiya is one of two remaining island-living leopards on Earth and the only apex predator in Sri Lanka. Despite its iconic status in Sri Lanka, robust research on the species has been limited to only a handful of scientific studies, limiting meaningful scientific recommendations for the species’ conservation and management. In this study, we conducted a single season camera trap survey in Sri Lanka’s largest protected area, Wilpattu National Park (1317 km2), located in the country’s northwest. Our objective was to estimate key ecological state variables of interest (density, abundance, sex-specific movement and spatial distribution) of this leopard subspecies. Our results indicate that Wilpattu National Park supports a density of 18 individuals/100 km2 (posterior SD=1.5; 95% HPD interval=16–21) with a mean abundance of 144 (posterior SD=15) individual leopards and a healthy sex ratio (f:m=2.03:1). The estimated activity range for male leopards > 2 years old was 49.53 km2 (Posterior SD=3.43; HPD interval=43.09–56.41) and for female leopards > 2 years old was 22.04 km2 (Posterior SD=1.82; HPD interval=18.34–25.65). This density falls at the higher end of published estimates for the species anywhere in its global range, based on similar methods. Given Sri Lanka’s limited size, this national park system should be considered as a critical stronghold that maintains a source population of leopards, contributing to the long-term population viability of leopards in the larger landscape.Full Tex

    New records of corallivory in the Red Sea

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    Quantifying Relative Diver Effects in Underwater Visual Censuses

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    Diver-based Underwater Visual Censuses (UVCs), particularly transect-based surveys, are key tools in the study of coral reef fish ecology. These techniques, however, have inherent problems that make it difficult to collect accurate numerical data. One of these problems is the diver effect (defined as the reaction of fish to a diver). Although widely recognised, its effects have yet to be quantified and the extent of taxonomic variation remains to be determined. We therefore examined relative diver effects on a reef fish assemblage on the Great Barrier Reef. Using common UVC methods, the recorded abundance of seven reef fish groups were significantly affected by the ongoing presence of SCUBA divers. Overall, the diver effect resulted in a 52% decrease in the mean number of individuals recorded, with declines of up to 70% in individual families. Although the diver effect appears to be a significant problem, UVCs remain a useful approach for quantifying spatial and temporal variation in relative fish abundances, especially if using methods that minimise the exposure of fishes to divers. Fixed distance transects using tapes or lines deployed by a second diver (or GPS-calibrated timed swims) would appear to maximise fish counts and minimise diver effects

    Bio-analytical Assay Methods used in Therapeutic Drug Monitoring of Antiretroviral Drugs-A Review

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    Background: Several clinical trials, as well as observational statistics, have exhibited that the advantages of antiretroviral [ARV] treatment for humans with Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome HIV/AIDS exceed their risks. Therapeutic drug monitoring [TDM] plays a key role in optimization of ARV therapy. Determination of ARV's in plasma, blood cells, and other biological matrices frequently requires separation techniques capable of high effectiveness, specific selectivity and high sensitivity. High-performance liquid chromatography [HPLC] coupled with ultraviolet [UV], Photodiode array detectors [PDA], Mass spectrophotometer [MS] detectors etc. are the important quantitative techniques used for the estimation of pharmaceuticals in biological samples. Objective: This review article is aimed to give an extensive outline of different bio-analytical techniques which have been reported for direct quantitation of ARV's. This article aimed to establish an efficient role played by the TDM in the optimum therapeutic outcome of the ARV treatment. It also focused on establishing the prominent role played by the separation techniques like HPLC and UPLC along with the detectors like UV and Mass in TDM. Methods: TDM is based on the principle that for certain drugs, a close relationship exists between the plasma level of the drug and its clinical effect. TDM is of no value if the relationship does not exist. The analytical methodology employed in TDM should: 1) distinguish similar compounds; 2) be sensitive and precise and 3) is easy to use Results: This review highlights the advancement of the chromatographic techniques beginning from the HPLC-UV to the more advanced technique like UPLC-MS/MS. TDM is essential to ensure adherence, observe viral resistance and to personalize ARV dose regimens. It is observed that the analytical methods like immunoassays and liquid chromatography with detectors like UV, PDA, Florescent, MS, MS/MS and Ultra performance liquid chromatography (UPLC)-MS/MS have immensely contributed to the clinical outcome of the ARV therapy. Assay methods are not only helping physicians in limiting the side effects and drug interactions but also assisting in monitoring patient's compliance. Conclusion: The present review revealed that HPLC has been the most widely used system irrespective of the availability of more sensitive chromatographic technique like UPLC.VRAID (ex DIPUC

    Experimental determination of the cost of lesion healing on Porites compressa growth

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    Digital immunohistochemistry implementation, training and validation: experience and technical notes from a large clinical laboratory

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    Aims: To consider the value proposition of digitisation of clinical immunohistochemistry services, and to develop an approach to digital immunohistochemistry implementation and validation in a large clinical laboratory. Methods: A methodology for slide scanning in the laboratory was developed, in addition to a novel validation exercise, to allow pathologists to identify the strengths and weaknesses of digital immunohistochemistry reporting, and train in digital immunohistochemistry slide assessment. Results: A total of 1480 digital immunohistochemistry slides were assessed by 24 consultant pathologists, with complete clinical concordance between the digital and the glass slide assessment observed. Certain stains were identified as being difficult/time consuming to assess using ×20 digital slides. These stains were rescanned at ×40, which improved the confidence of the pathologists to make a digital assessment. Full digitisation of immunohistochemistry slides was achieved, introducing six new steps into the pre-existing laboratory workflow. Conclusions: While initially encountering challenges in terms of workflow, our experience showed that a well-designed, adequately resourced and well-managed scanning process can minimise the delay in slides being made available for review. Our approach to validation highlighted the need for careful assessment of a digital pathology system and scanning protocols before pathologists are expected to transfer from the light microscope to the digital microscope for routine immunohistochemistry assessment

    A Markov chain probability model to describe wet and dry patterns of weather at Colombo

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