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

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

Quantifying Relative Diver Effects in Underwater Visual Censuses

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

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

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

Categories of relations and functional relations

Abstract: "We define relations and their composition in a category with ([Epsilon,Mu])-factorization structure, with [Mu] consisting of monomorphisms, but [Epsilon] not restricted to epimorphisms. We obtain an associativity criterion for composition of relations, and we study functional and induced relations.

Advancing socio-technical systems thinking: a call for bravery

Socio-technical systems thinking has predominantly been applied to the domains of new technology and work design over the past 60 years. Whilst it has made an impact, we argue that we need to be braver, encouraging the approach to evolve and extend its reach. In particular, we need to: extend our conceptualization of what constitutes a system; apply our thinking to a much wider range of complex problems and global challenges; and engage in more predictive work. To illustrate our agenda in novel domains, we provide examples of socio-technical perspectives on the management of crowd events and environmental sustainability. We also outline a research and development agenda to take the area forward

Forecasting the Occurrence of Rainfall in Selected Weather Stations in the Wet and Dry Zones of Sri Lanka

Two models were developed based on the Markov method to predict the occurrence of rainfall. Daily rainfall data from 9 meteorology stations in Sri Lanka namely, Colombo, Ratnapura, Kandy, Galle, Hambanthota, Batticaloa, Anuradhapura, Badulla and Trincomalee were analysed using these models. The results show that the models can forecast the status of a given day at an average of 73%. Higher agreement is seen for stations in the dry zone of Sri Lanka when compared with those in the wet zone. No significant difference was observed between the results obtained using the 1 st order Markov process and the 2 nd order Markov process. The models were not sensitive to the range of data used or the short-term fluctuations. 1