Hilman Syaeful Alam

Design and implementation of water quality monitoring for eel fish aquaculture

We have designed and implemented water quality monitoring using Raspberry Pi3. This device is made to monitor the water quality of aquaculture, which uses an aeration in the form of a microbubble. Some water quality parameters that used in this monitoring are dissolved oxygen (DO), acidity (pH), and temperature. Data processing devices used Raspberry Pi3 and python program used to create a sensor acquisition program and the program viewer. Tests carried out in two stages, those are sensors reading stability and device monitoring performance. The testing sensor stability conducted in the laboratory and the testing device monitoring carried out in aquariums using microbubble aeration. An implementation held on eel aquaculture using microbubble aeration. The test results also used for examination of microbubble aeration. The device can be used to monitor water quality in the laboratory, aquariums and eel aquaculture. All of the features in this monitoring device can function properly and smoothly.

The Structural Design of Six - Axis Force/Torque Sensor Using Virtual Prototyping Technique

The design of a six - axis F/T sensor is an important and challenging research to produce a sensor that is able to measure simultaneously the six - component force and torque accurately and efficiently. The structural design is one of the key issues to be considered to improve the performances of the sensor that cross coupling is the most important factor regarding a sensor quality. The purpose of this study is to design a six - axis F/T sensor that has a novel and compact design, has a low coupling error and can meet the design criteria such as mechanical strength, stiffness, and reliability in the receiving load. Virtual prototyping technique is applied with the aim to shorten the time and reduce the manufactu ring cost of the physical prototypes. In this study, the six - axis F/T sensor is designed using four cross beam symmetrically that is able to measure three axial forces ( , , ) and three axial moments ( , , ) . Based on the structural i ntegrity evaluation, the structure of the sensor will certainly secure to the plastic failure of materials because it is still in the area of the material elasticity. Then based on the simulation results of the strain, th e highest cross - coupling errors i s - 1.67% which is relatively small compared to the principal coupling error. Therefore, the design of six - axis F/T sensor using virtual prototyping

An Experiment of Spike Detection Based Mental Task with Ayes Movement Stimuli

In this paper, an experiment of spike detection based mental task with ayes movement stimuli is reported. The approximation of ICA algorithm is required to eliminate artifacts and detect a pike of brain activity according to the given stimuli which are normal, closed, and blinking ayes. A comparison of ICA algorithms based Extended Fourth Order Blind Identification and Algorithm for Multiple Unknown Signal Extraction is tested. The quality of the extracted signals is measured through the value of the signal to interference ratio and signal to distortion ratio. The extracted results indicate that the best spike detection is achieved using AMUSE algorithm.Keywords:EEG,spike, IndependentComponent Analysis (ICA).

Multi-objective optimization of the structural design of double end beam load cell

Multi-objective optimization of the structural design of double end beam load cell had been performed using a genetic algorithm. Two design variables were used to minimize the structural mass, to maximize the structural strength, and to maximize the level of measurement accuracy. Based on the optimal results, the weight reduction of the structure was successfully achieved of about 8.6%. The design safety factor reached 24 % larger than the yield failure criterion. Therefore, the structure will certainly secure against the plastic deformation. The accuracy of measurement of the load cell was predicted to reach the category of high accuracy due to the amount of strain on the strain gauge cavity managed to exceed ± 1600 με.

Rotor-Dynamic Characteristic Evaluation of Generator Geothermal Power Plant Using Finite Element Method

Dynamic characteristics of a critical speed of the rotor components at generator geothermal power plant is evaluated using finite element method. In this study, the critical speed is evaluated based on the over speed scenario at 100%, 120% and 150% of rated speed. The critical speed of the rotor is investigated in the Campbell diagram, which shows the relationship between natural frequency and rotational velocity of the system. Based on the rotordynamic evaluation using finite element, the critical speed at 100% and 120% of the operating speed occurs in the rotational speed of 2750 and 2837 rpm, while at 150%, the critical rotation occurs in the rotational speed of 2750, 2762 and 4051 rpm. It can be concluded that the speed ranges are the critical speed or the resonance region which can be as a direct cause of the component damage, therefore the operating speed should not work too long on that critical speed.

Numerical Study of Two-Phase Flow in Micro-/Nanobubble Generating Pump

Gas-liquid mixing pump is one of the multiphase flow problem in industrial applications as a micro-/nanobubble generator. However, very few report that studied the two-phase flow for application of microbubble generation because of the analysis complexity. In this paper, a steady state numerical simulation of gas-liquid two-phase flow in the gas-liquid mixing pump was employed to predict a performance and characteristic of fluid flow. Based on simulation results, it is demonstrated that the pump can work in self suction, and generates a vortex flow pattern at every stage of the impeller as regenerative. Performance pump of the numerical simulation is slightly higher than the design specifications Because of mechanical and volume losses was neglected. However, the evaluation method and simulation results from this work can be used as a reference for the design and improvement of the gas-liquid mixing pump.

Simulations of unpolarized light scattering by micro-bubble

Angle-resolved Mueller matrix element from unpolarized light scattering by micro-bubble in water is simulated using Mie scattering and discrete dipole approximation (DDA) method. This element of Mueller matrix can be used to determine the scattered light intensity to study the possibility of distinguishing the size of micro-bubble. The scattering of unpolarized light beam is simulated for three various wavelengths, 425, 625, and 825 nm. We consider the micro-bubbles sphere 1 - 10 μm with relative refractive indices to water as medium 0.75. The The result show that both Mie and DDA scattering simulation produce similar result and the result shows promising potential of using light scattering to distinguish and measure the micro-bubble sphere diameter size. Clear distinction is shown for 60 – 80 degree of detection angle.

Design control system for eel fish (Anguilla spp.) water aquaculture based Fuzzy Logic: MATLAB based simulation approach

Eel fish (Anguilla spp.) is catadromous fish species that born in saltwater, then migrate into freshwater as juveniles were growing into adults before spawning in the ocean. In the cultivation of eels enlargement, there are several factors that affect the growth of eels, such as water salinity (salt content in water), temperature, Dissolved Oxygen, current speed, acidity, and quality of water (or the microbial content of contaminants). This work, focuses on control and monitoring of water quality for eel aquaculture, by using 3 sensors, i.e. temperature, acidity (pH), and Dissolved Oxygen (DO) and will be done by fuzzy logic algorithm. The output of the fuzzy logic controller is to decide the time interval of switches that run the blower and nano-mixing pump simultaneously to keep the eel fish aquaculture at the desired value for parameter temperature, pH, and Dissolved Oxygen.

Remaining Life Assessment of the Generator Stator Insulation: A Case Study on Suralaya Coal Fired Power Plant in Indonesia

The failure of large generators in generating stations and industrial plants is mainly caused by the failure of the stator winding insulation. The combination of electrical, mechanical and thermal stresses that are accumulated by the number of start-stop times and operating hours can reduce the residual dielectric voltage as the main cause of the deterioration on the insulation. In this study, the remaining life assessment of the generator stator insulation was conducted based on the functional relationship between stresses and remaining dielectric voltage in the worst and average cases. The case study was conducted on the fourth of generator unit in SURALAYA Coal Fired Power Plant in Indonesia that had the service life of over 25 years. To validate the assessment results, partial discharges (PD) test was performed on the stator coils of the generator. Based on the results of evaluation, it was found that the remaining life of the fourth of generator insulation at the worst case had been come to end. For the average case, the remaining life of insulation for Unit 1 and Unit 2 was 12 year, while for Unit 3 and 4 was 17 year. Then from the validation results using the PD test, there was an evidence of the discharging of voids or delamination within the insulation, where the internal discharging was seen to be the most dominant factor from the discharge pattern. However, the PD magnitudes were still within reasonable limits, where the magnitude of the maximum discharge was 3,500 pC for the U phase, while in the V and W phase was 7000 pC, hence it was not categorized as an anomaly.

Magnetic Evaluation for Uprating 400 mW Coal Fired Generator

One of the considerations many power plants today is whether they can get more power out of their existing equipment especially generator. However, it is required design review and feasibility study in order to extend the operating life and increase the capability and reliability. In this study, analysis of magnetic field was performed due to power uprating in order to prevent a saturation of the magnetic field in the core laminate which can lead to the emergence of heat concentration. Based on the results of magnetic analysis using finite element, there are no saturation of the magnetic field in the core lamination which can lead to the magnetic saturation and heat concentration, both for existing and uprating conditions.Therefore, the increasing a design margin on the generators from the current design of the margin of 471,000 kVA to 494,550 kVA with the 0.85 power factor will not pose a problem as long as all of the following recommendations can be implemented. Although it is predicted, there will be no saturation and hotspots on the generator, but the risk of temperature rise due to the uprating should be reduced by replacing the stator winding using the Full Class F Insulation which is resistant to temperatures up to 155 °C.