Design of grounding system to protect against lightning and fault is important for both safety and reliability especially for Metropolitan Electricity Authority (MEA) as mostly Metropolitan Electricity Authority operates on overhead networks. This thesis assesses lightning performance for 69 kV 115 kV overhead subtransmission lines 24 kV distribution line using case study from Metropolitan Electricity Authority. Because of the limitation of the right of way distribution feeders are regularly installed together with subtransmission lines in a single concrete pole. Overhead Ground Wire (OHGW) installed at top of the pole and grounding system in concrete pole protects fault current or direct lightning surge to ground. Metropolitan Electricity Authority has developed lightning protection based on an IEEE standard which uses international data for insulation coordination. As a result reliability of the system is lower than the designed value. This thesis suggests a methodology to improve the performance in order to increase the reliability of subtransmission and distribution lines feeding distribution substations. This thesis recommends installation of addition external ground wire on the outer surface of the concrete pole to reduce top pole voltage and back flashover rate or installation of bundle overhead ground wires to protect shielding failure. As all the case studies presented in the thesis which constitute this thesis are applied to existing systems of Metropolitan Electricity Authority it is expected that the proposed methodologies can be served as useful practical guidelines for lightning performance assessment subtransmission lines and distribution lines of Metropolitan Electricity Authority.

Most of Metropolitan Electricity Authority (MEA) electric power system is using overhead line. It is 94% in the system including subtransmission distribution and low voltage system. All of them were installed on concrete pole. At present many public facilities have been built such as Sky-Train. It causes more constrains for construction with concrete pole due to lack of right of way. MEA needs to using electrical monopole plays an important role. It’s easier than concrete pole for construction and it requires less construction area than concrete pole. The thesis evaluation of lightning performance in subtransmission line 69 kV study on MEA. Case lightning strike on overhead ground wire (OHGW) at pole top of electrical monopole with suspension insulator Focusing on three factors is pole top voltage critical current and back flashover rate (BFOR). ATP-EMTP software is used for simulation. The results show that BFOR is reduced by 79% on electrical monopole structure with suspension insulator compared with existing concrete pole. BFOR is also reduced by 33.17% on concrete pole with external ground wire. The results could be served as a guideline in subtransmission line design and improvement in MEA power system.

This study investigates three different types of power plant include a trilateral cycle (TLC) subcritical organic Rankine cycle (ORC) and supercritical ORC power plant driven by geothermal heat source with mass flow rate 1 kg/s and temperature of 100๐C 110๐C and 120๐C. with 27 substances were examined as the working fluid of the power plant. While the net power output of 4.78 kW and 7.74 kW is obtained from the subcritical ORC with RC318 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 11.85 kW is obtained from the subcritical ORC with R227ea as its working fluid when the heat source temperature is at 120๐C. The net power output of 5.64 kW and 9.16 kW are obtained from the supercritical ORC with R218 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 12.88 kW is obtained from the supercritical ORC with R143a as its working fluid when the heat source temperature is at 120๐C. Furthermore the net power output of 7.96 kW 12.27 kW and 17.38 kW are obtained from the TLC plant with heptane as its working fluid when the heat source temperature are at 100๐C 110๐C and 120๐C respectively.

The objective of the research was to study suitability of professional competences indicators for mass communication office in digital age. The data were collected by using questionnaires sampling from 600 samples who were mass communication officers and lectures in mass communication universities. Data analysis employed frequency percentage arithmetic mean □(-/×) standard deviation (S.D). The research results revealed that there were the mass communication officer professional competences were 44 indicators including 10 indicators of printed media competences 13 indicators of radio and television broadcasting media competences 10 indicators of film media competences and 11 indicators of digital media competences.

The purpose of this research is to study on variables affecting fuel injection performance of biodiesel fuel injection and pyrolysis fuel. To test for variables affecting the fuel injection performance of biodiesel fuel injectors and pyrolysis fuel. By experimenting and modeling using computer programs to compare results. Finally for to use the information in the design of the car nozzle to work well with Biodiesel and pyrolysis fuel. The tested fuels which are pyrolysis fuel Bio-diesel fuel and diesel fuel are tested by tester Anton Paar@ Stabinger Viscosmeter (model SVM 3000/G2) ASTM D341 standard. The result shown that the density of the fuel is increasing normally. However the viscosity of the diesel and biodiesel are strong increased whereas the reducing of temperature is unaffected to the pyrolysis fuel. The fuel injection performance test showed that the density and viscosity of fuel were the major variables that affected the injection performance of the fuel. In case of using pyrolysis oil Injection performance is trend to higher other fuels and cold conditions.