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Teknosia
Published by Universitas Bengkulu
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Core Subject : Engineering,
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Articles 33 Documents
LOAD FREQUENCY CONTROL (LFC) PADA MIKROGRID MENGGUNAKAN BULK STORAGE BATTERY Ubaidah, Ubaidah; Khairudin, Khairudin
Teknosia Vol 3, No 2 (2017): XII, September
Publisher : University of Bengkulu

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Abstract

In electric power systems, the power generation should be balance to the power demand,otherwise the system frequency will deviate from the normal value. In microgrid system, thesystem frequency is prone to altere due to small damping factor condition. The utilizing of BulkStorage Battery is proposed to deal with this frequency deviation problem as a part of loadfrequency control. In this simulation, MATLAB SIMULINK R2014a was used and the simulatedmicrogrid consists of several smaller wind turbines generators, diesel generator, and photovoltaicare elaborated.In the simulation, same cases are introduced. The first cases is a network with the loaddisconnected from the system when it without and with battery, second cases is with the networkconnected to microgrid and the last is network connected to the microgrid, but the photovoltaic isdisconnected from the system.Based on the simulation results, it showed that the microgrid frequency with battery wasmore stable than without battery after changing load and release of the generators. Networkfrequency without microgrid was better than network frequency with microgrid when there is achange of amount of the load and generators release compared to the grid connected network.
PENGARUH PENAMBAHAN KATALIS TERHADAP SIFAT MEKANIS RESIN POLIESTER TAK JENUH , Jamasri, Kusmono, Hendri Hestiawan
Teknosia Vol 3, No 1 (2017): XI, Maret
Publisher : University of Bengkulu

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The aim of this research is to investigate the effect of catalist addition on the mechanical properties of polyester resin. The research materials are unsaturated polyester resin Yukalac 157 BQTN-EX7 and catalist methyl ethyl ketone peroxide (MEKP). The specimen based on ASTM D638 standard for tensile test and ASTM D790M standard for flexure test. Research specimens varied in catalist cocentration are from 0.5 to 3% with changed every 0.5%. Manufacture of specimens use acrylic material with hand lay-up method. The tensile test showed that the addition of catallist cocentration resulted decrease in tensile and flexure strength after 1% catalist cocentration. The highest tensile and flexural strength was found for the catalist cocentration of 1%, i.e. 62 MPa and 132 MPa respectively. Macrostructure observation of the fracture surface of tensile test showed relatively flat and shiny indicating that polyester resin composites are brittle.
KAJIAN EKSPERIMENTAL CACAT PADA BANTALAN BERDASARKAN LEVEL GETARAN Apriansyah, J. A.
Teknosia Vol 3, No 2 (2017): XII, September
Publisher : University of Bengkulu

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Bearing defect is generally caused by problems in lubrication and assembly. Predictivemaintenance is one of the best methods to identify its defect based on vibration level. In this paper,bearing defect is experimentally investigated by checking the vibration level occuring on bearing.Here, several types of bearing defect are considered, namely, defect on inner race, outer race, andball bearing. Firts, vibration on damaged bearing is captured. Then, vibration level is comparedto vibration level of intake bearing in order to know increasing vibration level. Moreover,captured vibration is also compared to ISO 2372 to check if bearing is still available or not. Levelvibration is captured by using vibtation tester putting on bearing in both radial direction and axialdirection. Each type of bearing defect is tested by varying shaft speed, that is 1000, 1500, and2000 rpm. The result shows that vibration level increases by increasing shaft speed. Vibrationlevel increases about 489% for bearing defect on inner race, 190% for bearing defect on outerrace, and 108% for bearing defect on ball.
PERENCANAAN BENDUNG TIPE MERCU BULAT UNTUK MENDUKUNG DAERAH IRIGASI PEMATANG GUBERNUR KOTA BENGKULU , Besperi, Gusta Gunawan, Rizky Humaira Putri
Teknosia Vol 3, No 1 (2017): XI, Maret
Publisher : University of Bengkulu

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Abstract

Pematang Gubernur of Bengkulu city has good irrigation area, but since the last three years, 300 hectares of agricultural land is no longer cultivated because water demand for irrigation area is not up to the last rice terraces. It is caused by a weir not functioning optimally. This research aimed to plan the dimensions of the weir to be suitable to the nowadays condition of Pematang Gubernur’s hydrology. Hydraulic calculations done by using primary data and secondary data. The primary data used is the width of the river, the depth of the river, the river base elevation. Secondary data which achieved is network schmea. Apron floor calculation use lane method, meanwhille the calculation of weir head, stilling basin, intake gates, flushing gate and weir stability use mathematics equation. Discharge use on calculation is 37,29 m3/s with a return period of 100 years. The weir use rounded weir head with radius rounded head is 1,512 m and 1,68 m height. The effective width of the weir is 4,796 m. the stilling basin planned is the type vlughter with a length of 6,711 m. The length of the floor surface is 13,79 m. Width of intake gate dan flushing gate are 1 m with 1m in high. The design has passed the requirement of slide stability, shear stability, eccentricity stability and soil bearing capacity.
ANALISIS EFISIENSI MOTOR INDUKSI PADA KONDISI TEGANGAN NON RATING DENGAN METODE SEGREGATED LOSS Sudibyo. P, M. Khairul Amri. Rosa, Afriyastuti Herawati, Samuel
Teknosia Vol 2, No 17 (2016): X, September
Publisher : University of Bengkulu

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Abstract

Induction motor is the most widely used motor in industry, but the problem of voltage instability from PLN that the motor work at out of its rating (non rating), make poor performance of induction motor, one of the problem is decrease of efficiency. Condition of non rating motor voltage (undervoltage and overvoltage) will decrease quality of induction motor. This is important to evaluate the motor to know  its condition. One of the best method for it is segregated loss method  based on IEEE-112 standart. With this method can be evaluated the condition of induction motor without stopping the motor. This method use induction motor parameters such as motor current, input power and slip to analyze power losses of motor. Evaluation results of induction motor with segregated loss method are the highest efficiency at  0.86 N.m loading of 52.979% for nominal voltage, 46.6% for undervoltage and 51.94 for overvoltage. Efficiency at 0.97 N.m loading is 52.258% for nominal voltage, 48.68% for undervoltage and 51.94% for overboltage. Efficiency at 1.2 N.m loading is 52.979% for nominal voltage, 51.24% for undervoltage and 53.24% for overvoltage.
PENGARUH FREKUENSI GETARAN TERHADAP POTENSI LIKUIFAKSI Mase, Lindung Zalbuin
Teknosia Vol 3, No 2 (2017): XII, September
Publisher : University of Bengkulu

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Liquefaction is a lost of shear strength phenomenon in saturated sandy soil due to excess porewater pressure during earthquake shaking. Several factors influencing liquefaction are relative density ofsand, grain size, ground water level, magnitude of earthquake, and earthquke shaking duration. Theexperimental study using shaking table was performed to investigate liquefaction potential. Soil sample issandy soil with relative density (RD) less than 33% and can be categorized as loose sand. The dyanmicmodelling in this experimental study included peak ground acceleration (PGA) of 0.4g, shaking durationof 32 sec, and vibrational frequency of 1.4 Hz; 1.6Hz, and 1.8Hz. The parameter used to determineliquefaction in this study is excess pore water pressure ratio (ru), which reflects that liquefaction couldhappen if ru > 1 and vice versa. The result show that the applied loads were able to trigger liquefaction insandy layer. Besides, the liquefaction duration and ru max tend to increase when the vibrationalfrequencies increase.
DIRECTIONAL WEIGHTING DEMOSAICKING METHOD TO ENHANCE THE QUALITY OF DIGITAL CAMERA IMAGES , Anindita Ayu Prastiwi, Boko Susilo, Endina Putri Purwandari
Teknosia Vol 3, No 1 (2017): XI, Maret
Publisher : University of Bengkulu

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Abstract

Many digital cameras currently use single sensor technology. The sensor is mounted on a Color Filter Array algorithm to estimate the image color in three image color channel red, green, and blue. The process of calculating the estimated two color channels which is missing in one pixel is referred to demosaicking process. This research aims to make a demosaicking implementation application. Directional weighting method is used to suppress false color and zipper effect artifacts possibility. Peak Signal to Noise Ratio (PSNR) value is used as a comparison of image quality that produced. This system is built using Matrix Laboratory (Matlab). System development method that used is the Waterfall model and Data Flow Diagram (DFD). The final result of this research is an application that can perform demosaicking process in digital camera image, which achieve higher PSNR as big as 100% in testing of noiseless image from LASIP database and image from a digital camera from the surrounding environment, also 93.33% for image with gaussian noise from LASIP database and image with poisson noise from LASIP database.
MODIFIKASI NEBULIZER KOMPRESOR DENGAN MENAMBAHKAN PENGATURAN TIMER DAN DETEKTOR CAIRAN OBAT SEBAGAI BATASAN WAKTU TERAPI PEMBERIAN OBAT PADA PENDERITA ASMA Fernando, Alex Surapati, Faisal Hadi, Andica
Teknosia Vol 2, No 17 (2016): X, September
Publisher : University of Bengkulu

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Modifications of  nebulizer compressor in this study were made and can be used to solve problems in the treatment of asthma therapy. Asthma is a symptom that is caused by abnormalities of the respiratory tract, causing increased sensitivity to environmental stimuli. Symptoms are often seen in people with asthma usually is cold / sneezing, coughing, itchy throat. Nebulizer is a device used in the treatment of asthma. This tool can transform the drug particles from a liquid into a very fine grains (steam). Because the drug is converted into a gas (steam), the drug is easier to be absorbed so that the effects of the drug seem faster than oral medications. Overall the nebulizer has worked and the functioning properly fit the desired time and the limits of medicine. The output voltage sensor of potions detector around 0.726 to 1.221 volts with a range of drug volumes 1-6 cc. Overall the percentage of error in testing time is between 6:49%. The average time required for evaporation of the drug in 1 cc of liquid drug is approximately 638.86 seconds.
Corrective Maintenance Bearing on Rolling Machine of 1st and 2nd Crepper Jumbo (Case Study in PTPN VII of Padang Pelawi Bussines Unit, Seluma Regency, Bengkulu Province) Puspawan, Angky
Teknosia Vol 3, No 2 (2017): XII, September
Publisher : University of Bengkulu

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Maintenance is the work done on the engine or engine components that are useful for theimprovement of the engine so that the performance of these components operate properly withoutany interference from other objects.By conducting field observations, some of the tools and materials used in the installationprocess on a machine Rolling Bearing of 1st and 2nd Crepper Jumbo is fitting tool, lubrication,bearing fitting tool, different types of hammers and keys and pads kinds of Cylindrical RollerBearings. Used bearings have a characteristic density of 7.9 g/cm3, 700 HV10 hardness, modulusof elasticity 210 kN/mm2, thermal expansion 12•10-6/K and the electrical resistivity of 0.4•10-6?m.From the results obtained on the actual cause of damage to bearings in machines Rollingof 1st and 2nd Crepper Jumbo are due to loading large on the shaft and casing, user/ machineoperation is continuous, and installation errors bearing with a hammer which resulted in damagedue to collisions that hard (sharp impact). Corrective maintenance is the best solution for thiscondition without damage and the production process does not stop. In doing bearing maintenance,maintenance procedures in accordance with the recommended, then a performance rolling bearingof crepper jumbo goes as expected by the company. Corrective maintenance is plannedmaintenance done to improve and enhance the condition of the bearing so as to achieve acceptablestandards.
PEMANFAATAN TEKNOLOGI TEPAT GUNA MESIN BALANCING RODA MOBIL , Restu Prayoga, A. Fauzan, Dedi Suryadi
Teknosia Vol 3, No 1 (2017): XI, Maret
Publisher : University of Bengkulu

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This research deals with design and manufacture of a balancing machine for car’s wheels. Concept design of balancing machine is carried out based out capacity needed. Balancing machine consist of frame, driver motor, v-belt, pulley, shaft, bearing, and coupling. First, frame of the balancing machine is considered. Here, dimensions of frame are fixed, namely 750mm of length, 150mm of wide, and 825mm of high. Material used for frame is ASTM A36 with standard C-profile. Strength of the frame is analyzed by using finite element model. Meanwhile, other components such as driver motor, v-belt, pulley, shaft, bearing, and coupling are numerically designed. Furthermore, balancing machine is manufactured. In order to control quality of the product, manufactured machine is experimentally tested referred to ISO 3272. Results show that machine is qualified to be used for wheel balancing with maximum speed 700 rpm.

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