https://ir.kdu.ac.lk/handle/345/3823 2026-04-08T14:23:55Z 2026-04-08T14:23:55Z Wirasinghe, SC Pasindu, HR Saedi, S Kattan, L https://ir.kdu.ac.lk/handle/345/1156 2023-04-26T11:52:13Z 2013-01-01T00:00:00Z

Preliminary analysis of ring rail lines for the western province of Sri Lanka Wirasinghe, SC; Pasindu, HR; Saedi, S; Kattan, L The Western Province of Sri Lanka is a developing urban conglomerate and the economic engine of the nation. In the long run, it will require an upgrade of the existing radial rail lines and possibly one or two partial ring rail lines. We investigate two such partial ring lines based on some theories developed by Saidi (2013) et al. article full text

2013-01-01T00:00:00Z Gunawardana, DDVP https://ir.kdu.ac.lk/handle/345/1146 2023-04-26T11:32:21Z 2013-01-01T00:00:00Z

Development of electrical energy saving assistant Gunawardana, DDVP The main objective of the device introduced in this paper is to help reducing the peaks of daily demand curve of national power grid, with the introduction of an automatic power disconnection function. The device simultaneously provides electrical consumers with a graphical indication of electrical energy usage of single phase electronic installation and several other useful parameters. The device mainly consists of an energy metering unit, a processing unit, a real time clock calendar and a user interface. There is an auxiliary line to supply power to the non - critical electrical appliances such as Refrigerators, AC machines, etc. and a 433MHz Radio Frequency range Amplitude Modulation Receiver unit to receive information on peak hours of the Daily Demand Curve which will be sent to the processing unit of the system for the function of turning off the auxiliary power line. The device can be fixed to any single phase electrical installation of 230V and 40A (max). In the consumers view point, this device not only shows information about daily consumption as a graph but also helps the consumer to plan his next month energy consumption. In order to illustrate the effectiveness of this device, a detailed analysis was conducted to show how the device reacts to the behaviour of the demand curve. Secondary data about various sources of power generation and consumption were used to analyse the total impact on demand curve and finally the energy saving and financial benefits were estimated. article full text

2013-01-01T00:00:00Z Samarakoon, MB https://ir.kdu.ac.lk/handle/345/1139 2023-04-26T11:40:24Z 2013-01-01T00:00:00Z

Application of derived models for the prediction of municipal solid waste generation rates in developing countries Samarakoon, MB Municipal Solid Waste Management (MSWM) is a complex process that requires a lot of information from various sources such as factors on waste generation and waste quantity forecasts. Waste generation rates are affected by socioeconomic development, degree of industrialisation, and climate. Generally, greater the economic prosperity and higher the percentage of urban population, greater is the amount of solid waste produced. It is essential to know the quantity of waste generated to plan a Municipal Solid Waste (MSW) management strategy for a given region. Various researchers have attempted to construct models to predict the MSW generation rates. In developed countries there are even models available to predict MSW generation rates, however very few researchers have developed models to predict MSW generation rates in developing countries. Therefore, it is a necessity to use MSW generation prediction models for urban and suburban municipalities in developing countries such as Sri Lanka. This study reviews previously tested models related to municipal solid waste generation and identifies possible factors which will help in identifying crucial design options. There are two different ways to classify models when it comes to analysis of MSW generation rates. They are: factor models that use factors describing the processes of waste generation (Consumption or Utilisation) and Input�output models based on the flow of material to or from waste generators (Removal). There are a number of independent and dependent variables that have been used to explain the overall quantity of partial or entire MSW streams. The study identifies that there is a need for an overall forecast model which identifies future growth in waste generated per capita. The major deficiencies of this study were the selection of few number of models and the use of qualitative approach rather than using statistical tools. Therefore, it is recommended to use a statistical analysis to facilitate better approach for the current models. article full text

2013-01-01T00:00:00Z Weerakoon, GMPR Jinadasa, KBSN Herath, GBB Mowjood, MIM https://ir.kdu.ac.lk/handle/345/1134 2023-04-26T11:06:00Z 2013-01-01T00:00:00Z

Impact of hydraulic loading rate on performance of constructed wetlands for wastewater treatment Weerakoon, GMPR; Jinadasa, KBSN; Herath, GBB; Mowjood, MIM Wastewater generation is increasing at an exponential rate as a result of rapid population growth and urbanization. Sri Lanka in its way forward to become a hub in Asia will have to give an immense attention for treatment of wastewater in the field of pollution control, which is a challenge in developing countries like Sri Lanka, due to the limitations of resources and expertise. Constructed wetlands where water, plants and microorganisms interact to improve the quality of water are growing popular as an effective, low-cost wastewater treatment technology, which does not necessarily require skilled personnel to run the system. However, these systems are not yet widely spread in Sri Lanka due to lack of information. This study investigated the performance of laboratory scale vertical subsurface flow (VSSF) and horizontal subsurface flow (HSSF) constructed wetland systems subjected to varying hydraulic loading rates (HLRs) at tropical condition. Four wetland beds of size 1.4 m x 0.5 m x 0.6 m (Length x Width x Height) were constructed and arranged - two beds as VSSF systems and the remaining two beds as HSSF systems. All four beds were filled with 10 - 20 mm gravel as the wetland media and planted with locally available emergent macrophyte, narrow-leaf cattail (Typha angustifolia). Each wetland system was supplied continuously with synthetic wastewater at different HLRs of 2.5, 3.5, 5, 7.5, 10, 12.5, 15, 20 and 30 cm/day at 12 days cycles over a period of four months. Samples were collected at the end of each HLR application and analysed for five day biochemical oxygen demand (BOD5), total suspended solids (TSS), fecal coliform (FC) and Total coliform (TC). Results showed a decrease of removal efficiencies of BOD5, TSS, FC and TC when increasing the HLR. However it was observed over 80% of BOD5, 40% of TSS, 86% of FC, 90% of TC removal efficiencies in HSSF wetland systems and over 85% of BOD5, 29% of TSS, 89% of FC, 88% of TC removal efficiencies in VSSF systems respectively from 2.5 - 30 cm/day HLRs. Results of this study can be used in field applications of CWs where frequent water flow fluctuations occur. article full text

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