Longshore sediment transport in the swash zone at Desaru Beach

This study examined the processes of longshore sediment transport in the swash zone at Desaru beach, Johor. It focused the suitability of sediment trap on sandy beach and beach profile’s survey to determine the direction of longshore transport. Field measurements were carried out by using sediment trap, Global Positioning System (GPS) kit and water level logger. Data collected are sediment samples, beach profile and tides. Laboratory sediment analysis also conducted to determine the size, density and porosity at the area. It was found that the sediment trap is unsuitable to be used at Desaru beach. This could be due to highly turbulent waves and sediment transport from the cross-shore direction that had fully covered the trap with sediment. The beach profile survey shows that the direction of the longshore transport is coming from northwest to southeast of the beach. From the analysis of sediment samples, it was found that the sediment size ranges from 0.33 mm to 0.35 mm with median diameter of 0.34 mm. From the experiment, the average porosity is approximately 0.43, whereas the average density is about 2635 kg/m3. As conclusions, the sediment trap is unsuitable to be used at sandy Desaru beach. The direction of the longshore transport is from northwest to southeast of the area during Northeast monsoon

Production Of Chitinase By A Locally Isolated Fungus

Chitin and chitinolytic enzymes are gaining importance for their biotechnological applications. Particularly, chitinases which have been widely used in agriculture to control plant pathogens. Chitinases and chitooligomers produced by enzymatic hydrolysis of chitin have also been used in human health care products. The success in employing chitinases for different applications depends on the supply of highly active preparations at reasonable cost. In this study, isolation and screening of fungus were carried out. Trichoderma sp. was selected due to the ability to produce chitinase enzyme with biggest clear zone formation on Chitinase Detection Agar (CDA) for qualitative confirmation. The slides were viewed under light microscope to determine the isolated fungi morphology. Shake flask fermentation using Trichoderma sp. was carried out to produce chitinase enzyme. Different types of media were investigated to find the best medium for chitinase enzyme production using colloidal chitin as the reference substrate. It was observed that the highest chitinase activities (0.70 U/mL) were obtained using Kawachi Medium at day 4 of fermentation. Kawachi Medium was selected as the basal medium for induction studies. Several types of inducers that included chitin colloidal and direct chitin, N-acetylglucosamine, glucosamine hydrochloride and chitosan oligosaccharides were used to investigate the feasibility of different inducers for enhancing chitinase enzyme production. The results indicated that all the tested inducers supported chitinase production by Trichoderma sp. It was suggested that the level of chitinase production were regulated or induced by the type of media and inducers used. In addition, it showed that colloidal chitin was the second best inducer after NAG. For economic considerations, colloidal chitin was chosen as the inducer for further study. The effect of different concentration of the inducer selected was studied on chitinase enzyme production. Low colloidal chitin concentration at 0.3% (w/v) gave the highest chitinase activity of 0.72 U/mL. Additionally, raw shrimp waste was also employed to induce chitinase enzyme production. Raw shrimp waste that was subjected to different pre-treatments including sun-dried, acid treated, alkali treated and enzyme treated were used to find cheaper alternative substrates for chitinase enzyme production. Sun dried and ground raw shrimp waste gave the highest chitinase enzyme production. The pretreated raw shrimp waste were also analysed for their composition include protein, moisture and ash content using proximate analysis

Pengaruh Aspect Ratio Pada Perancangan Motor Induksi Tiga Fase.

ABSTRACT This research investigates the influence of aspect ratio on the main physical dimensions, equivalent circuit parameters, and torque in the design of three phase induction motors. Software for the design of three phase induction motors can be applied to the designing of the motor component. Input data for the program consist of power, voltage, frequency, speed, efficiency, power factor, and various values of the aspect ratio from 1.00 to 4.00. The output of the program are the main physical dimensions of three phase induction motors. The result of the research shows that the increases of aspect ratio, maximum torque, and full load torque raise the length of the core (L), but the diameter of the stator bore (D) decreases. Key word: Aspect ratio, rotor lilit, rotor sangka

Development of PID voltage control for DC motor using arduino

This project focuses on the design and implementation of PID voltage control for DC motor. DC motor is a machine that widely used due to excellence speed control for acceleration and deceleration with effective and simple torque control. The PID controller is employed to control the output voltage of three phase controlled rectifier to run a DC motor as a load. The function of this PID controller is to correct the error in order to achieve the target value of desired voltage. The modelling, control and simulation of this project has been implemented using MATLAB/Simulink Software version 2013a. The Pulse Width Modulation (PWM) signals generated from MATLAB/Simulink model will be downloaded into Arduino microcontroller. Arduino microcontroller board is an interfacing device between MATLAB/Simulink model and actual hardware. The PWM signals from Arduino will step up using gate driver and then will be sent to power MOSFET gates for triggering rectifier. The output produced from this controlled rectifier is in DC form. The open loop and closed loop simulations analyses for PID control voltage were successfully conducted. Results show that the error of voltage for closed loop is lower compared than open loop. Furthermore, hardware has been setup to verify the MATLAB/Simulink model. From here, the speed of DC motor is increased as the controlled output voltage is increased. This project contributes to the efficiency and robustness of controlling output voltage for DC motor being used in industry based on PID controller rather than using conventional method like rheostat armature control and direct on line (DOL) starter

Metode Yang Dipergunakan Untuk Memperbaiki Respons Stabilitas Peralihan Pada Sistem Tenaga Listrik

Power system stability, in general terms, may be defined as its ability to response to a disturbance from its normal operation or by returning to a condition where the operation is again normal. Stable operation of power system requires a continuous match between input energy to the prime movers and the electrical load on the system. A synchronous power system has transient stability if, after a large sudden disturbance, it can regain and maintain synchronism. Techniques for improving the transient stability response of power system are excitation control, fast valving, series compensation, reducing excess of energy during the transient, reducing the impact of the disturbance on network switching and power modulation of direct-current line

Kinerja bahan isolasi non keramik di daerah tropis

Non-ceramic insulatos have been increasingly accepted by industry and utilities to replace porcelain and glass insulators because of the well-known advantages the non ceramic insulators have, such as light weight, ease of handling, reduce installation and maintenance cost, vandalism resistance, and inproved contamination performance. How ever, non-ceramic insulation material, likes epoxy resin has some disadvantages. It is very sensitive, if it used in high temperature and in a very humid areas, and also in area where exist high intensity of ultraviolet radiation. These climates condition unfortunately found in most area in Indonesia which will cause leakage current then develops which may lead tq flashover that could be followed by an outage of the power system. In order to reduce the incidence of non-ceramic insulator flashover, this paper presents the results of an investigationon the electrical performance of artificially contaminated epoxy resin insulation material. The specimens of epoxy resin insulating materials are based on diglysidil ether of bisfenol-A (dgeba), metaphenylene-diamine (mpda) as curing agent, and silica filler were used. Part of specimens is coating by silicon compound Experimental method was carried out through the following procedure : (I) the contaminant coating on specimen surface in fog chamber and simulation of ultra violet radiation, (2) the ac voltage was applied between two electrodes inserted into specimen surface, (3) the measurement of leakage current on contamination specimens surface, and (4) the calculation of equivalent salt deposit density (esdd) On the basis of the results, it can be concluded the increase both esdd and uv radiation on the specimens surface cause the increase of leakage current. Silicone compound coating on specimen surface is able to suppress the development of leakage current

SENSOR WIRELESS INTERFACE MODULE

In the oil and gas industry, wired sensor network is the traditional and commonly used. Nowadays, there is a new trend in network communication which is the wireless sensor network. Hence, the wireless technology is now growing fast and keeps improving with time. The objectives of this project are to find an economical wireless solution for the wireless sensor network, design, build and test a short-range sensor wireless interface module. A lot of study and research in communications and instrumentation has to be made in order to design the system. The designed system consists of a RTD transmitter, A/D converters, signal interface, a WiFi Access Point and a WiFi enabled PC. Based on the surveys conducted in this project, the WiFi technology is suitable for this project because of its maximum transfer speed, maximum distance and maximum devices that it can connect at one time. This system also can reduce maintenance cost and save time

Kegagalan Berbagai Jenis Bahan Lantai terhadap tegangan bolak-balik

,ABSTRACT Nowdays, ceramic floor material are widespread used in building developments. There is a question whether good characteristic attached to porcelain, the material of which is common used in power insulation, is as good as that of ceramic one. This research compared the dielectric strength of ceramic floor material, porcelain floor material and cement material floor when alternating voltage is applied It is found that the dielectric strength of ceramic floor material is 7 times as big as the cement floor material, but it is half of the the porcelain floor material dielectric strengt

PENGARUH POROSITAS TANAH TERHADAP PENTANAHAN DALAM SISTEM TENAGA LISTRIK = The Influence of Soil Porosity on Grounding in Electric Power System

ABSTRACT This study was intended to find out the relationship between soil porosity and grounding in electric power system. Using cylider ground rod with 3/4 " diameters and various length could eliminate potensial difference between metal and soil, and could stabilize the voltage in electric power system by grounding its neutral point on star relation system. The location of this study was Semarang municipality, taking hilly and lowland area for the samples. The aim was to find out the soil porosity and mineral level distinction and also saturation degree in different electrode profoundity in eah objects/locations. The examination took place through distinct test by one line variants analysis (ANOVA) with windows SPSS 10.0 program. The relationship between soil porosity and grounding was analyze with correlation by SPSS program. The result indicated that Tukey and Boferroni tests for the parameters of soil porosity, mineral level, saturation degree, and stability value with the same profoundity for each data source area, showed different conclusions. Analysis of the soil porosity showed a significant correlation. So it can be said that grounding factors is influenced by soil porosity faktor. Key word : soil porosity, soil resistance and ground in electric power syste

Kinerja Pengoperasian Motor Induksi 3-Fase Pada Sistem Tenaga 1-Fase Dengan Menggunakan Kapasitor

In many rural areas where only single-phase power is available from the local utility, operation of induction motors that drive large loads can be a problem. For loads up to about 20 hp, single-phase induction motors can be used with easily. For larger loads, the single-phase induction motors required a specific designed starting windings and control circuits. Such induction motors are often considerably higher in cost than the equivalent 3-phase induction motorsand is usually more economical and more efficient to use a 3-phase induction motor even if it must be supplied with a single-phase source. One way to do this is to connect capacitors at the winding circuits across the terminal of the induction motors. The data of induction motor used was 1.5 kW three-phase induction motor, 220/380 V/Y6.2/3.6 A50 Hz1400 rpmB class0.84 power factor with 4 poles of _stator using capacitor on one-phase power supply. The performance of induction motor was analyzed based on the output power Vs input current, power factor, efficiency, network output torque, and the rising of temperature of the stator\u27s winding. The method used in this research was focused on the reactive power of the three-phase induction motor and current densities within each winding. The experimental results showed that the three-phase induction motor used could be operated well on one-phase power supply using 128,21pF of capacitor with the output power of 726.26 W, 0.961 leading power factor, input current 5.2 A, network output torque 5.3 N-m, efficiency 66%, rotor speed 1310 rpm and winding temperature 82.1 CC. So the induction motor could be operated safely according to the IEC and NEMA standards. Keywords : capacitor circuit, reactive power of three-phase induction motor, current densities