Exploration of the Potential of Reclaimed Waste Cooking Oil for Oil-Immersed Power Transformers

In this study, reclaimed waste cooking oil is proposed as an alternative insulating liquid for oil-immersed power transformers. Reclamation is carried out by heating a mixture of waste cooking oil and Fuller’s Earth adsorbent and followed by filtration. Propyl gallate antioxidant is then added into the filtered oil. Four oil samples are investigated in this study: (1) new cooking oil (NCO), (2) waste cooking oil (WCO), (3) reclaimed oil (RWCO) and (4) reclaimed oil with propyl gallate antioxidant (RWCOPG). The AC breakdown voltage, moisture content and total acid number is measured for all oil samples according to the ASTM D1816, ASTM D1533 and ASTM D974 standard test method, respectively. The results show that the AC breakdown voltage is highest for the RWCOPG sample (28.08 kV), which is 0.4% higher than the standard requirement of 20 kV. The moisture content for this sample is 180.60 ppm, which is still below the allowable limit of 200 ppm. However, the total acid number is highest for the RWCOPG sample which suggests that it has high acidity. It is indicated that the antioxidant-reclaimed waste cooking oil has potential to be used as an insulating liquid for oil-immersed power transformers, but much work is still needed to reduce the total acid number of this oil

Modeling and System Identification using Extended Kalman Filter for a Quadrotor System

Quadrotor has emerged as a popular testbed for Unmanned Aerial Vehicle (UAV) research due to its simplicity in construction and maintenance, and its vertical take-off, landing and hovering capabilities. It is a flying rotorcraft that has four lift-generating propellers; two of the propellers rotate clockwise and the other two rotate counter-clockwise. This paper presents modeling and system identification for autostabilization of a quadrotor system through the implementation of Extended Kalman Filter (EKF). EKF has known to be typical estimation technique used to estimate the state vectors and parameters of nonlinear dynamical systems. In this paper, two main processes are highlighted; dynamic modeling of the quadrotor and the implementation of EKF algorithms. The aim is to obtain a more accurate dynamic model by identify and estimate the needed parameters for the quadrotor. The obtained results demonstrate the performances of EKF based on the flight test applied to the quadrotor system

Performance Evaluation of DC Microgrid System for Residential LED Lighting Application

This paper proposes LED lighting applications DC microgrid system with compact LED lamps system for residential. Conventionally, the residential lighting system used the supply from the authorized energy supplier to power up all the electrical appliances at home. In Malaysia, the voltage distributed to residential area is 240V AC. However, most of electrical appliances at home are not driven in AC. Therefore, the electrical appliances that driven by DC requires AC/DC converter to operate. But the conversion process of the converter creates losses due to the switching of the device. For these reasons, the use of low voltage direct current (LVDC) distribution is attracting interest. In order to reduce the losses, the design of direct current (DC) microgrid at residential is proposed. This research aims to compare conventional residential lighting systems with proposed residential lighting system. The comparison conducted by simulation using MATLAB Simulink and experiment. The simulations are carried out to illustrate the power consumption for all cases. The experiment set up to compare the performance of all cases in term of power consumption, luminance, and voltage and current harmonic. Furthermore, this experiment consider suitable wiring design of the proposed system includes size of cable. As the results, the proposed system shows the better performance than the conventional system

Online surface condition monitoring system using time-frequency analysis technique on high voltage insulators

Insulations in high voltage engineering are a concern to users in terms of its performance, expected lifetime, and long-time reliability. Insulation failure can allow leakage current (LC) to flow and causes tracking and erosion as well as flashover. Tracking and erosion test complying with BS EN 60857-2007 are conducted to capture the set of leakage current (LC) patterns which are capacitive, resistive, and discharge activities. For verifying the performance of the insulators, an automated monitoring system is needed to reduce diagnostic time of the LC. Even though Fast Fourier Transform (FFT) gives useful information on the analysis of LC, it has limitation in nonstationary signal. Therefore, this research presents the analysis of time frequency distribution (TFD) which is spectrogram that represents the LC signals in the joint time frequency domains which provide temporal and spectral information. The results obtained from the developed monitoring system allow the user to identify leakage current performance in real time. The developed system has shown the capability in detecting the performance of insulating materials as well as identifying the characteristics of the surface discharges

Comparative study of electrical test methods on detecting transformer faults

Condition monitoring of distribution and power transformers is of utmost importance to utilities due to cost effectiveness concerns. The common faults that occur in transformers are short circuits and winding deformation. To date, there are many established test methods used to detect these faults. In this study, three test methods (insulation resistance (IR), transformer turn ratio (TTR), and frequency response analysis (FRA)) were compared to assess their effectiveness in detecting short circuit and winding deformation in a three-phase transformer. Based on the results, the three test methods were found to be capable of detecting short circuits. However, only TTR and FRA can detect winding deformation, and FRA can further indicate which phase is faulty. Therefore, it is concluded that FRA is more effective in detecting short circuit and winding deformation of a three-phase transformer

A novel study on the effect of rapid biofloc as pellet feed on the survival rate and water quality of mud crab, Scylla olivacea culture

In order to promote the optimum survival rate of mud crab, Scylla sp., in crablet culture, green technology approaches must be developed to increase the yield of mud crab production. The application of biofloc in Scylla sp. culture was proven successful in promoting a good crablet performance and sustaining a good water quality condition. Therefore, due to its importance, this study aimed to determine the survival rates of Scylla olivacea crablets cultured in tanks, fed with pelleted rapid biofloc aggregates. Three feeding trials were conducted consisting of commercial pellet (CP), rapid biofloc pellets (BP) and a mix of rapid biofloc pellets with commercial pellets (BP+CP) and were cultured up to 13 weeks of culture periods. The mud crab crablets were fed twice a day, while water exchanges were only conducted once per week. The survival rates were calculated at the end of the culture period while water quality parameters were regularly monitored. Overall, our findings showed that the survival rate in the BP+CP treatment was the highest with 30%, while 23.3% and 10% in CP and BP treatment, respectively. The water parameter was in optimum range in CP, BP and BP+ CP treatment tanks where pH ranged from 8.19 to 8.26, temperature between 26.68°C to 26.69°C and salinity between 32.17ppt to 33.16 ppt. Ammonium, NH4 + was below an optimum range with, 0.18mg/L in BP treatment and 0.21 mg/L in BP+CP as compared to CP. Meanwhile, nitrite, NO2 - was identified below 1mg/L which ranged between 0.07 and 0.08 mg/L. Therefore, it can be concluded that combination of commercial and pelleted rapid biofloc aggregates have the potential capability to increase the survival rate of mud crab crablet culture while sustaining good water quality parameters and nutrient level

Structural and thermal analysis of bio-based polybenzoxazine derived from liquefied empty fruit bunch (EFB) via solventless method

A bio-based polybenzoxazine demonstrating excellent thermal properties was synthesized using phenolic and its derivatives derived from liquefaction of empty fruit bunch (EFB) fibres to fulfill green chemistry principles. The liquefied EFB was reacted with furfurylamine and paraformaldehyde through a Mannich condensation reaction. For comparison purposes, a guaiacol polybenzoxazine was synthesized using guaiacol as a phenolic component reacted with similar amine and aldehyde. Both types of polybenzoxazine synthesized from liquefied EFB and guaiacol were named L-fa and G-fa, respectively. The structural analysis was performed using Fourier-Transform Infrared (FTIR) and proton Nuclear Magnetic Resonance (1H NMR). It was observed that the synthesis of benzoxazine groups for both types of polybenzoxazine was successful with the formation of the oxazine ring. Thermal stability showed that liquefied EFB polybenzoxazine (L-fa) has higher thermal stability above 360 °C compared to guaiacol-polybenzoxazine (G-fa), which is higher is 280 °C due to the complex structure of the lignin derivative in the liquefied EFB. For polymerization behavior, L-fa exhibit two exothermic peaks compared to three peaks on G-fa, indicating that L-fa is more reactive due to additional polymerizable sites present in L-fa. This work widens the synthesis route for the preparation of bio-based benzoxazine derived from oil palm waste which will perpetuate outstanding evolution towards the sustainable development of the bio-based polymeric industry

Study on the implementation of different biofloc sedimentable solids in improving the water quality and survival rate of mud crab, Scylla paramamosain larvae culture

Microbial communities in biofloc technology (BFT) are responsible in minimalize water exchange and producing microbial proteins that are beneficial as a supplementals diet for mud crab, Scylla paramamosain larvae culture. Therefore, a study was conducted to determine the effect of bacterial communities in different sedimentable solids in order to improve the water quality and survival rate of S. paramamosain larvae culture. The results successfully identified that the number of pathogenic bacteria, Vibrio spp. decreased when the heterotrophic bacteria thrived in treatment tank with 4 ml/L sedimentable solids. The group of heterotrophic bacteria were able to adapt in developing their population while effectively uptake the ammonium and nitrite components. The ammonium and nitrite level in treatment tank depleting at an early stage of the experiment, and constantly low until the end of experiments (ammonium <0.20 mg/L, nitrite <0.10 mg/L). The survival rates of S. paramamosain larvae in both control and treatment tanks were identified <2.0%, however, sedimentable solids of 2 ml/L was identified suitable to be applied in crab larvae culture as it can help to reach megalopa stages within 17 days of culture period. Overall, it can be concluded that bacteria communities in biofloc are able to regulate nutrients load and maintaining water quality and also help in increased survival rate and development performance in the low sedimentable solids of biofloc culture treatment. Therefore, sedimentable solids of 2 ml/L is suggested to be potentially applied in S. paramamosain larvae cultures from this research finding

Kesediaan pelajar tingkatan empat mempelajari mata pelajaran pengajian kejuruteraan awam di Sekolah Menengah Teknik Seri Iskandar, Perak

Kajian ini dijalankan bagi melihat kesediaan pelajar dari aspek minat, kemahiran Bahasa Inggeris dan pengetahuan sedia ada pelajar dalam mempelajari mata pelajaran Pengajian Kejuruteran Awam di Sekolah Menengah Teknik Seri Iskandar. Kajian deskriptif berbentuk tinjauan ini melibatkan sampel kajian yang terdiri daripada 78 orang pelajar tingkatan empat sesi 2007 yang mengambil Jurusan Kejuruteraan Awam. Instrumen kajian yang digunakan dalam kajian ini ialah soal selidik kerana ia lebih praktikal dan menjimatkan masa. Nilai kebolehpercayaan instrumen kajian ini adalah _ = 0.906. Data-data mentah dianalisis menggunakan Statistical Packages for the Social Sciences 13.0 (SPSS) untuk mendapatkan frekuensi, peratus dan min. Dapatan kajian menunjukkan bahawa kesediaan pelajar dari aspek minat, kemahiran Bahasa Inggeris dan pengetahuan sedia ada dalam mempelajari mata pelajaran Pengajian Kejuruteran Awam di Sekolah Menengah Teknik Seri Iskandar berada pada tahap yang sederhana. Hasil ujian-t pula menunjukkan tidak terdapat perbezaan minat dan kemahiran Bahasa Inggeris antara pelajar lelaki dan perempuan dalam mempelajari mata pelajaran Pengajian Kejuruteran Awam. Walaubagaimanapun, terdapat perbezaan pengetahuan sedia ada antara pelajar lelaki dan perempuan dalam mempelajari mata pelajaran Pengajian Kejuruteran Awam. Kajian ini boleh menjadi panduan kepada pihak sekolah, Jabatan Pelajaran Negeri (JPN) dan Kementerian Pelajaran Malaysia (KPM) untuk membantu pelajar dalam mengikuti mata pelajaran ini serta dalam mata pelajaran teknikal yang lain. Kajian ini juga boleh dijadikan panduan untuk kajian lanjutan

Kesediaan pelajar tingkatan empat mempelajari mata pelajaran pengajian kejuruteraan awam

Kajian ini dijalankan bagi menentukan kesediaan pelajar dari aspek minat, kemahiran bahasa Inggeris dan pengetahuan sedia ada dalam mempelajari mata pelajaran Pengajian Kejuruteraan Awam di Sekolah Menengah Teknik Seri Iskandar. Kajian deskriptif berbentuk tinjauan ini melibatkan sampel kajian yang terdiri daripada 78 orang pelajar tingkatan empat sesi 2007 yang mengambil Jurusan Kejuruteraan Awam. Instrumen kajian yang digunakan dalam kajian ini ialah soal selidik. Nilai kebolehpercayaan instrumen kajian ini adalah α = 0.906. Data-data mentah dianalisis menggunakan Statistical Packages for the Social Sciences 13.0 (SPSS) untuk mendapatkan frekuensi, peratus dan min. Dapatan kajian menunjukkan bahawa kesediaan pelajar dari aspek minat, kemahiran bahasa Inggeris dan pengetahuan sedia ada dalam mempelajari mata pelajaran Pengajian Kejuruteran Awam di Sekolah Menengah Teknik Seri Iskandar berada pada tahap yang sederhana. Hasil ujian-t pula menunjukkan tidak terdapat perbezaan minat dan kemahiran bahasa Inggeris antara pelajar lelaki dan perempuan dalam mempelajari mata pelajaran Pengajian Kejuruteraan Awam. Walau bagaimanapun, terdapat perbezaan pengetahuan sedia ada antara pelajar lelaki dan perempuan dalam mempelajari mata pelajaran Pengajian Kejuruteraan Awam. Dapatan kajian ini boleh dijadikan asas kepada pihak sekolah, Jabatan Pelajaran Negeri (JPN) dan Kementerian Pelajaran Malaysia (KPM) untuk membantu pelajar dalam mengikuti mata pelajaran ini serta dalam mata pelajaran teknikal yang lain