110 research outputs found

    Design and Modelling of Wave Energy Converter and Power Take-Off System

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    Ocean wave energy contains the largest energy density amongst all renewable energy. In Malaysia, the highest wave energy in the South China Sea is 12kW with maximum wave amplitude of 2 meters. This paper presents the design and modelling of wave energy converter and power take-off system that suitable for Malaysia in order to obtain the highest output of electrical power. A point absorber made up of a floating buoy connected by a fibre rope is used as wave energy converter. Linear permanent magnet generator has been used as the power-take-off system. This generator exploits directly the incoming sea wave vertical motion. This wave energy converter and power-take-off model have been developed and implement in Matlab. The model included wave energy, buoy water interaction, and linear generator. To extract highest wave energy, different parameters have been applied to the linear generator. Simulation results are presented showing three effects of three different parameters; winding coil turns, magnetic field strength and tooth width of the stator

    Study of Tensile Properties for Aluminum 6061 Reinforced With AISI 1060 Steel Machining Chips

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    The present study focuses on the tensile properties of Aluminum 6061 reinforced with AISI1060 Steel machining chips. Three different types of samples of aluminium 6061 reinforced with AISI 1060 steel machining chips were prepared using stir casting. The tensile test was conducted using universal test machine (UTM) for fabricated composites to study the tensile properties of aluminium 6061 reinforced with steel machining chips AISI 1060.The samples were prepared with different composition of AISI 1060 steel machining chip of 5%, 10% and 15% according to the weight fraction of parameter variable. Two casting processes were applied in this project namely stir casting and sand casting process. The stir casting was used to mix the two different metals to become a composite at temperature between 750℃ to 800℃ in a furnace while sand casting was used to fabricate the samples into ASTM-E8M standard for tensile testing. The results showed that the samples with higher reinforcement percentages of steel machining (15%) showed higher tensile stress and higher modulus value characteristic compared to other samples. The experiment proved that the reinforcement material has good mechanical properties compared to the pure material

    IDENTIFICATION OF INTELLIGENT CONTROLS IN DEVELOPING ANTI-LOCK BRAKING SYSTEM

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    This paper presents about the development of an Antilock Braking System (ABS) using quarter vehicle model and a control structure is developed to represents an ABS and conventional braking model. Different type of controllers is proposed to develop the ABS model. Antilock braking system (ABS) is an important part in vehicle system to produce additional safety for driver. This system is known as one of the automobile’s active safety. In general, Antilock braking systems have been developed to reduce tendency for wheel lock and improve vehicle control during sudden braking especially on slippery road surfaces. In this paper, to deal with the strong nonlinearity in the design of ABS controller, an intelligent controller has been identified. The controllers such as PID and Fuzzy Logic are proposed to control the stopping distance and longitudinal slip of the wheel. Comparison results between these two controllers generated using Matlab SIMULINK

    Characterization of vancomycin-resistant Enterococcus isolates from broilers in Selangor, Malaysia.

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    Vancomycin-resistant Enterococcus (VRE) is an emerging nosocomial pathogen in humans. The use of antibiotics in human therapy and in the production of food animals has been incriminated in the emergence of this organism. The present study describes the distribution of VRE species, the vancomycin-resistant genes detected, the vancomycin resistance pattern observed, and the genetic diversity of the isolates found in live broiler chickens in Malaysia. Overall 140 VRE were isolated with species comprising Enterococcus faecalis (48%), Enterococcus faecium (25.7%), Enterococcus gallinarum (12.1%), Enterococcus casseliflavus (1.4%) and other Enterococcus species (12.8%). Vancomycin resistance gene vanA and intrinsic genes vanC1 and vanC2/3 were detected in the study population. VanA was detected in 15 (63.9%) of E. faecium, 23 (22.4%) of E. faecalis and in 3 (17.6%) E. gallinarum isolates. E-test was conducted on randomly selected 41 of the isolates and the minimum inhibition concentration (MIC) of vancomycin for five (11.9%) of tested isolates is more than 256µg/ml. Genotypic analysis using random amplified polymorphic DNA (RAPD) showed genetic diversity within the Enterococcus species

    Performance Analysis of A Spark Ignition Engine Using Compressed Natural Gas (CNG) as Fuel

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    AbstractCompress natural gas (CNG) is also considered as alternative fuel to produce better emission in a vehicle, but the main disadvantage of CNG in comparison to liquid fuel (gasoline) is the lack of power produced for the same capacity of engine. In this study, the single cylinder spark ignition (SI) engine was selected in order to study the effect CNG into the spark ignition engine. The hydraulic dynamometer was used to study the performance of CNG and liquid fuel. The usage of sensor also applies to the test to extract the data during the ignition stage for liquid fuel and CNG. The heat generated by both types of fuel also had been extracted from the tested engine in order to define which usage of fuel would cause a higher heat transfer to the engine. From this study, the result showed that pressure inside cylinder for CNG is 20% less than gasoline. CNG fuel also produced 23% less heat transfer rate compared to gasoline. The results explained why CNG produced 18.5% lower power compared to liquid fuel (gasoline).So, some improvement needs to be done in order to use CNG as fuel

    Case report: Unusual cause of difficulty in intubation and ventilation with asthmatic-like presentation of Endobronchial Tuberculosis

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    Endobronchial Tuberculosis is hazardous in causing circumferential narrowing of tracheobronchial tree despite the eradication of tubercle bacilli in the initial insult from Pulmonary Tuberculosis. They may present as treatment resistant bronchial asthma and pose challenge to airway management in the acute setting. We present a 25 year-old lady who was newly diagnosed bronchial asthma with a past history of Pulmonary Tuberculosis that had completed treatment. She presented with sudden onset of difficulty breathing associated with noisy breathing for 3 days and hoarseness of voice for 6 months. Due to resistant bronchospasm, attempts were made to secure the airway which led to unanticipated difficult intubation and ventilation. Subsequent investigations confirmed the diagnosis of Endobronchial Tuberculosis and patient was managed successfully with anti TB medication, corticosteroids and multiple sessions of tracheal dilatation for tracheal stenosis. This case highlights the unusual cause of difficulty in intubation and ventilation due to Endobronchial Tuberculosis, which required medical and surgical intervention to improve the condition

    Electrical discharge machining of polycrystalline diamond using copper electrode – finishing condition

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    Research on machining process of Polycrystalline Diamond (PCD) is becoming important as the material was believed suitable to be used for cutting tools of advanced aeronautical structure. Electrical Discharge Machining (EDM) was regarded as the suitable method to machine PCD due its noncontact process nature. The objective of this research is to determine the influence of several EDM parameter such as sparking current, pulse duration, and pulse interval to the material removal rate and surface roughness of the machined PCD. Instead of significantly influenced the material removal rate, the sparking current was also highly influenced tha surface roughness. Highest material removal rate of approximately 0.005mm3/s was recorded by the EDM process with the highest current used of 5A, and lowest pulse interval of 1µs. The influence of pulse duration is not clearly seen at the lowest pulse interval used. On the other hand, 0.4µm was the lowest surface roughness value obtained in this research indicated by the highest sparking current, highest sparking duration and lowest sparking interval of 5A, 1µs and 1µs respectively

    Chemical Potential Shift in Nd2x_{2-x}Cex_{x}CuO4_{4}: Contrasting Behaviors of the Electron- and Hole-Doped Cuprates

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    We have studied the chemical potential shift in the electron-doped superconductor Nd2x_{2-x}Cex_{x}CuO4_{4} by precise measurements of core-level photoemission spectra. The result shows that the chemical potential monotonously increases with electron doping, quite differently from La2x_{2-x}Srx_{x}CuO4_{4}, where the shift is suppressed in the underdoped region. If the suppression of the shift in La2x_{2-x}Srx_{x}CuO4_{4} is attributed to strong stripe fluctuations, the monotonous increase of the chemical potential is consistent with the absence of stripe fluctuations in Nd2x_{2-x}Cex_{x}CuO4_{4}. The chemical potential jump between Nd2_{2}CuO4_{4} and La2_{2}CuO4_{4} is found to be much smaller than the optical band gaps.Comment: 4 pages, 5 figure

    A Green's function approach to transmission of massless Dirac fermions in graphene through an array of random scatterers

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    We consider the transmission of massless Dirac fermions through an array of short range scatterers which are modeled as randomly positioned δ\delta- function like potentials along the x-axis. We particularly discuss the interplay between disorder-induced localization that is the hallmark of a non-relativistic system and two important properties of such massless Dirac fermions, namely, complete transmission at normal incidence and periodic dependence of transmission coefficient on the strength of the barrier that leads to a periodic resonant transmission. This leads to two different types of conductance behavior as a function of the system size at the resonant and the off-resonance strengths of the delta function potential. We explain this behavior of the conductance in terms of the transmission through a pair of such barriers using a Green's function based approach. The method helps to understand such disordered transport in terms of well known optical phenomena such as Fabry Perot resonances.Comment: 22 double spaced single column pages. 15 .eps figure

    The Effectiveness Of Visual Research In Enhancing The Cultural Knowledge And Practices In Creative Industry

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    This paper aims to explain the effectiveness of visual research to investigate cultural objects as the way to enhance cultural knowledge and practices in the creative industry. Based on the experiential study that was participated by the researcher, has discovered the factors that influenced the effectiveness in visual research based on the three different case studies which particularly on the cultural heritage of Parang Bajau at Kg. Siasai, Kota Belud, Ring Ladies of Embhan Community at Padawan, Sarawak, and Megalith Cultures of Kelabit Highlands at Bario, Miri. Through the comparisons based on the three case studies has identified three factors of visual research which is internal, external and the context of the research subject. These factors will contribute for better documentation, especially in visual, particularly for practicing researcher in the cultural studies, enhancing the information of cultural knowledge, developing the creative economy through the representation of visual cultures and most significant for the society purposes that own the culture
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