IPTEK Journal of Proceedings Series
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Novel Centralized Control Battery Operation, on Microgrids to Supply The Load Priority
Full text linkPriority loads, in micro grid is preferred load to always get the power supply. Battery function, in micro grid, in addition, functioning as a storage energy, it also serves as a stabilizer of network, due to intermittent of energy sources, both solar and from wind. As energy storage, battery is intended to supply energy when other sources of energy is not available. So far, the mechanism of battery operation, distributed on each generation, so that when operation standalone, battery capacity is not in optimal level. In this study, proposed, method of centralized control battery operation, which would regulate the use of battery operation, especially to supply the load priority. So that the power supply from the battery to the load priority, it would be optimal in optimal level when other sources are no longer, by utilizing parameters weather and load forecast
Bioremoval of Chromium, Copper and Cadmium by Bacillus cereus in Simulated Electroplating Wastewater
Full text linkHeavy metal pollution is one of environmental problems, which is caused by the discharge of improperly treated industrial wastewater. Electroplating industry generates wastewater containing heavy metals, which include chromium, copper and cadmium. Biological treatment using bacteria has been considered as a new alternative for treatment of heavy metal containing wastewater. The bacteria play an important role in the bioremediation of heavy metal contaminated environment. Bacillus cereus was known as cosmopolitan bacteria with high resistance to pollutants. This study was conducted to measure the viability of two strains of Bacillus cereus in chromium, copper and zinc containing cultures, and the bioremoval efficiencies of the heavy metals.. The bioremoval efficiencies were measured using spectrophotometric method. The bacterial viability was measured according to the Optical Density of the culture. The results showed that both B. cereus strains were viable in culture containing chromium, copper, and cadmium with different concentrations. The highest tolerance of the bacteria was observed in chromium containing culture, where highest chromium bioremoval efficiency of 51.8% was performed by ATCC 9632 strain at chromium concentration of 102.4 mg/L, in varied concentration range up to 360 mg/L. Whereas the highest copper bioremoval efficiency of 100% was achieved in the cultures of B. cereus ATCC 1178 and ATCC 9632 at copper concentration of 2 mg/L in tested concentration range up to 10 mg/L. The highest cadmium bioremoval efficiency of 77% was achieved by ATCC 9632 strain at concentration of 15 mg/L in concentration range up to 25 mg/
System Application of Genetic Algorithm for Scheduling Optimization Study Using Java (Case Study : Department of Computer System UNTAN)
Full text linkcheduling of lecture in a university is a college activities into the work place and time that there is room in such a way so as to minimize the violation of the scheduling problems of a lecture. Problems that are often referred to as the University timetabling problem ( UTP ) is, requires a lot of consideration include the number of students, number of teachers who are not proportional to the number of courses, the amount of space used, as well as lecture predetermined time. Scheduling lectures with the automation system is very important because it can save you hours of work and provide optimum solutions in a short time, which can increase productivity, the quality of teaching and learning, and quality of service. One method that can be used to complete the course scheduling problem is a genetic algorithm approach. Genetic algorithm is an optimization tool that models the principles of evolution. Genetic algorithm is able to find a globally optimum solution in the search space is very complex. By using an initial population of solutions is encoded and selected based on its quality, and then used to create a new population using crossbreeding and mutation process of the initial individuals. Evaluation function is used to calculate the hard constraints and soft constraints can be met. This study discusses the scheduling college located in Department of Computer Systems Untan. The purpose of study is to optimize the college scheduling and to make easier the scheduling job with make a college scheduling softwar
Design of Curriculum Matrix for Robotics Education Derived from Bloom's Taxonomy and Educational Curriculum of 2013
Full text linkEven though robotics have gaining an attention from students of every educational level since elementary school up to higher education, their impact in student’s education itself is still relatively small. Most of the robotics competitions in Indonesia are still focus on the result but not in the process. This paper presents an educational matrix of curriculum based on robotics which focused on the process and learning outcomes of the education. The proposed Curriculum Matrix is derived from Bloom's Taxonomy which synchronized with the Educational Curriculum of 2013 from the Indonesian Ministry of Education and Culture. Hereafter, the activities of education are designed based the available robotics module together with the designed Curriculum Matrix. By using the Curriculum Matrix, the proportion of education activities can be evaluated to achieve the learning outcomes for the specified educational level more easil
Investigation of Flow and Heat Transfer Characteristics in Two-Phase Flow Through Evaporator of Diffusion Absorption Refrigerator (DAR)
Full text linkThe application of the cooling system becomes very important for a comfortable and almost all public buildings in Indonesia using the cooling system. The cooling system is commonly requires considerable electrical power to drive the compressor used for the vapor compression cooling system in operation. Different with the diffusion absorption refrigeration system, all cycles in the system are occurred by natural circulation where the refrigerant is pressurized (partial) lower in the evaporator is obtained with the aid of an inert gas that can be either hydrogen or helium, which is mixed with the refrigerant gas, but not also react. The study was conducted by flowing the refrigerant at the evaporator copper tube passes that are part of a diffusion absorption refrigeration machine. Long dimension of passes evaporator is 2.38875 m. The method used in this study is the experimental and numerical approach, which is using Multiphase Flow Fluent CFD 6.3. simulation to validate the experimental observations of flow.Through this study, the fenonena happened to be validated by experimental observations numerically. Also can be seen flow characteristics of refrigerant flowing along the evaporator and heat transfer phenomena that occur
Development of a ‘Fish Tail’ Rudder to Improve a Ship’s Maneuverability in Seaway
Full text linkThe maneuverability of a ship at seaway is strongly influenced by a design of rudder. An innovative design of rudder based on a tail shape of fish was developed with the intent of improving an efficiency of ship maneuverability. Two designs of rudders were proposed i.e. the rudder of forked which is a rudder with an area reduction on the middle part, and the lanceolate shape or a rudder with additional area on the middle part. In evaluation of the rudder designs performance, the numerical approach of Computational Fluid Dynamic (CFD) was applied to determine a side force generated by rudder using the commercial software of FLUENT. Numerical simulations were performed on the rudder designed of rectangular, forked and lanceolate which had similar a surface area with the variations of rudder angle such as 100, 200 and 300 due to the uniform fluid flow at a constant speed. Further simulations was performed on the two forked rudder designed which takes into account the influence of propeller due to fluid flow on the rudder surface. It had shown the velocity of fluid flow behind the shaft of propeller very small in which the middle part of the rudder produced less lift force compare to the other part of rudder. Mathematical and numerical model of ship maneuvering were developed in order to evaluate the performance of a ship maneuvering in seaway based on the IMO standards on turning test. The simulation results had shown the rudder of forked produce the ship maneuvering performance that exceeds the performance of rectangular rudder as well as lanceolate rudder
Synthesis of UiO-66 Using Solvothermal Method at High Temperature
Full text linkUiO-66 solids have been synthesized using solvothermal method in which reaction mixtures of zirconium tetrachloride (ZrCl4) and 1,4-benzenedicarboxylic acid (BDC) in N-N'-dimethylformamide (DMF) were heated at 140 °C for 6, 12, 24, 36, 48, 72 and 144 hours, respectively. The weight of reaction products, in the form white powder, increased with the increase in heating time up to 72 hours, then decreased. Characterization results using XRD showed that the diffractogram of the solid obtained at heating time of 6 h had the same pattern to that of reported UiO-66, characterized by a main peak with a high intensity at 2θ of 7.3°, as well as other characteristic peaks with lower intensity at 2θ of 8.4°; 25.6° and 30.6°. The longer the heating time (12 and 24 h), the lower the intensity of the main peak. When the reaction mixtures were heated for 36 h or longer, the obtained solid diffractograms showed that the main peak intensity at 2θ of 7.3° was lower than the second peak, and new peaks appeared at 2θ of 13.8°; 15.8° and 17.5°. SEM micrographs showed that the solid synthesized for 6 h was in the form of clusters of square morphology, whereas solids synthesized for 72 h showed needle-like surface morpholog