The response of a high voltage transformer with various geometries of core joint design

The core losses in a three phase transformer can be significantly reduced by improving the core joint geometry. The researchers were applied numerous types of T-joint designs in order to reach the optimum design that can be used in three phase transformer to reduction the losses. Two types of T-joint design are presented in this paper; T-joint with 90° butt-lap design and T-joint with 45° mitered design. A 3-phase distribution transformer was simulated in 3D using Ansys Maxwell software. The core loss for a three-leg three phase transformer rated 1000 KVA and the flux density distribution are investigated. The simulation results show the core losses were increased up to 3% and the flux density was increased to reach more than 22% flux density become higher when using T-joint with 90° butt-lap design as compared with T-joint with 45° mitered design

Sterilization and extraction of palm oil from screw pressed palm fruit fiber using supercritical carbon dioxide

The supercritical carbon dioxide (SC-CO2) was successfully used in the complete sterilization as well as simultaneous extraction of oil from screw pressed palm fruit fiber. The studies were conducted at different temperatures (40, 50, 70 °C) and pressures (13.7, 20.7 MPa) for 60 min of extraction period. The bacteria, gram negative (Bacillus), present in the sample was completely killed at 20.7 MPa and 50 °C. Palmitic and oleic acid were found to be the major fatty acids in extracted oil. More saturated fatty acid were extracted at 50 °C and lower operating pressure (13.7 MPa). The unsaturated components, such as linoleic and oleic acids were extracted at higher pressures of 27.6 and 34.5 MPa, respectively. The fatty acids composition of the extracted oil analyzed using gas chromatography–mass spectrometry (GC/MS) includes caprylic, capric, lauric, myristic, palmitic, margaric, stearic, oleic, linoleic, linolenic, arachidic and gadoleic acids

Analysis on magnetic flux density and core loss for hexagonal and butt-lap core joint transformers

This paper presents the results of new hexagonal configuration at the T-joint of three-phase transformer core. The proposed model is compared with previous T-joint design, Butt-lap, which is widely used at present by many transformer manufacturers. The magnetic flux density distribution and core loss of a transformer rated 1000kVA are analyzed for the two types of T-joint design. The 3D simulation are carried out by using the ANSYS-Maxwell software. The results show that the magnetic flux density of the hexagonal shape T-joint is well distributed compared to that in the Butt-lap T-joint design. The core loss for the proposed model (hexagon) T-joint indicates a reduction of more than 11 % compared to the Butt-lap T-joint design

New optimization technique to design the core of three-phase transformer

Reduction losses in three-phase transformers have drawn the attention of researchers, in the recent years. In this study, an intelligent algorithm employing particle swarm optimization (PSO) has been used to get the optimum T-joint design of a core in a three-phase transformer. This technique was employed to design a new geometry of a joint to obtain the minimum loss in a three-phase transformer. In achieving this target, a 3D finite element method had been used to simulate the proposed transformer model. Power losses in the core and winding losses had been considered as the heat sources, and the results were validated based on the test data obtained from transformer factory. The results presented that the total losses have been decreased up to 10% compared to the corresponding values from common designs. Moreover, the core losses have been reduced in the range of 11% compared to similar parameters in the conventional design

One- and Two-Dimensional Hydrological Modelling and Their Uncertainties

Earth processes, which occur in land, air and ocean in different environment and at different scales, are very complex. Flooding is also a part of the complex processes, which need to be assessed accurately to know the accurate spatial and temporal changes of flooding and their causes. Hydrological modelling has been used by several researchers in river and floodplain modelling for flood analysis. In this chapter, factors affecting flash flood, possible options of basic input parameters in one- and two-dimensional hydrological models in data sparse environment, some case studies and uncertainty in hydrological modelling were discussed. This discussion will help the readers to understand the flooding factors, selection of input parameters in data sparse environment, a brief insight of one- and two-dimensional hydrological models and uncertainties in their input and model parameters and model structures

Lightning severity classification utilizing the meteorological parameters: a neural network approach

This paper presents a technique of predicting lightning severity on daily basis by using meteorological data. The data used is supplied by Global Lightning Network (GLN) from WSI Corporation. The input of the system consists of seven meteorology parameters which had been provided by Malaysia Meteorology Service with minimal fees. Input parameters are the Minimum Humidity, Maximum Humidity, Minimum Temperature, Maximum Temperature, Rainfall, Week and Month. The output of the system determines the severity of lightning predictions in three stages; Class1: Hazardous; Class2: Warning; and Class3: Low Risk. Two training algorithms that have been tested in this study namely the Gradient Descent with Momentum Backpropagation (traingdm) and the Scaled Conjugated Gradient Backpropagation (trainscg). The traingdm has indicated better accuracy of 70% compared to the trainscg whilst in contrast; trainscg has demonstrated approximately 4 times faster training compare to traingdm

Effective treatment of palm oil mill effluent using FeSO4.7H2O waste from titanium oxide industry: Coagulation adsorption isotherm and kinetics studies

Palm oil mill effluent (POME) is a highly polluted industrial wastewater that may cause detrimental environmental pollution if discharged directly due to its biochemical oxygen demand (BOD) and chemical oxygen demand (COD) concentrations. In the present study, the performance of FeSO4.7H2O waste from titanium oxide industry was investigated in removing BOD, COD, and total suspended solids (TSS) from POME. Jar tests were conducted with varying coagulant doses (1e5gL�1 ), pH (2e10), and temperature (40e80 C) as a function of treatment time ranging from 5 to 90 min. Results show that the FeSO4.7H2O waste can remove about 70% COD, over 80% BOD, and over 85% TSS in a single stage coagulation treatment. The coagulation adsorption mechanisms for the removal of COD, BOD, and TSS from POME were investigated based on BrunauereEmmetteTeller (BET), Freundlich, and Langmuir isotherm models. The removal of COD, BOD, and TSS from POME was best described by the Freundlich isotherm model, indicating that coagulation adsorption occurred in a multilayer formation with nonuniform distribution of adsorbed particles. The coagulation adsorption kinetics studies revealed that the removal of COD, BOD, and TSS from POME using FeSO4.7H2O waste followed the second-orderkinetics modeling. Our findings suggest that the FeSO4.7H2O waste has the potential to be utilized as a coagulant for treating POME in compliance with the standard discharge limits

Optimization of arecoline extraction from areca nut using supercritical carbon dioxide.

The mass transfer of arecoline using supercritical carbon dioxide (SC-CO2) from areca nut is studied by analyzing the diffusion coefficient derived from Crank equation for sphere model. Comparisons of the SC-CO2 extracted yield under various conditions showed that the combination of pressure at 10.3 MPa and temperature of 50°C provided the optimum condition for extraction, followed by extraction at 40°C and 25.6 MPa. From the diffusion coefficient analysis, the optimum conditions also gave the highest coefficients. It was found that the yield is directly proportional to the values of the coefficients

Kajian penghasilan polipina: the conversion of pineapple leaves to white fabric / Wan Yunus Wan Ahmad … [et al.]

The Malaysian pineapple leaf fibre (PALF) from Yankee type was converted to fabric through fibre scrapping, hand spinning and hand loom weaving. It was scoured and bleached to remove impurities and turn to natural white colour. The project was to reduce pineapple leaves waste in plantation but a lot of works needs to be carried out to speed up the process of conversion to fibre, yarns and fabric. Process of conversion can be much faster and in larger volume by using suitable machineries and trained workers

Hard cocoa butter replacers from mango seed fat and palm stearin

The blending effects of mango seed fat (MSF), extracted using supercritical fluid, and palm stearin (PS) to formulate hard cocoa butter replacers (CBRs), were investigated. The triglycerides (TG), thermal properties and solid fat content (SFC) of the formulated blends were determined using different chromatographic and thermal techniques. All the blends had three main TGs; namely, 1,3-dipalmitoyl-2-oleoylglycerol (POP) (8.6 to 17.7%), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS) (12.6 to 19.6%), and 1,3-distearoyl-2-oleoyl-glycerol (SOS) (37.2 to 31.4%), with SOS being the major component. The melting peak temperatures gradually increased and shifted towards higher temperatures with PS. The crystallization onset temperatures increased, while the offset decreased with PS. The SFC did not drop to 0% at 37.5 °C, which was shifted to 0% at and above 40 °C for some blends. The studies revealed that CBRs could be prepared by blending MSF and PS, and they could be utilized by chocolate manufacturers in tropical countries