Browsing by Author "Tambunan, Walfred"

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    EFEK ADITIF Bi2O3 TERHADAP MIKROSTRUKTUR DAN KOEFISIEN NON LINEAR VARISTOR ZnO.
    (2014-03-27) Tambunan, Walfred; Malik, Usman
    The varistor ZnO has been made by using raw materials: ZnO (E-Merck) and additive 0 %, 2.5 %, 5%, 7.5%, and 10% wt. Bi2O3. The important property of varistor ZnO is coefficient of non linier () and it can give influence correlation between current I and voltage V. The mixing process of raw materials was done by using magnetic stirrer and liquid acetone as media, and then was dried at 60oC, and also grinded until passing 400 meshes. Pellet was made by using pressing 50 MPa, and fired at 1050oC with holding time 2 hours. After firing, all samples are characterized, such as: measurement of coefficient of non linier (), and observation of microstructure by using Scanning Electron Microscope (SEM). The results show that sample without additive has  less than 5 and this sample has not properties as varistor, but the highest value of  is 64 for sample with additive 7.5% Bi2O3. The result of photos SEM shows that the increase of percentage of additive Bi2O3 can influence of formation grain boundary and grain size. Where, value of coefficient of non linier () is depend on existing of grain boundary and thickness of grain boundary.
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    KONSENTRASI KANDUNGAN LOGAM BERAT TERHADAP KUALITAS AIR SUNGAI SINGINGI DI DAERAH DESA KOTO BARU KECAMATAN SINGINGI HILIR KABUPATEN KUANTAN SINGINGI
    (2016-02-01) Mulyani, Sry; Syech, Riad; Tambunan, Walfred
    A concentration of heavy metals (Pb, Cd, Zn), an electrical conductivity and water density at Sungai Singingi by using an experimental method have been carried out. Water sampling at Sungai Singingi that crosses the village of Koto Baru is conducted three times at five points where the distance between the point is 10 m as long as 40 m. The equipment used are the concentration of heavy metals by using Atomic Absorption Spectrophotometer (AAS), the electrical conductivity by using a Total Dissolved Solid Meter (TDS meter), and the density of the water by using a Hydrometer. The results shows that the concentrations of heavy metals lead (Pb) are highest in five points, namely 0.0889 mg/l and the lowest one is of -0.0296 mg/l. The highest the concentration of heavy metal cadmium (Cd) in the five points is 0.0028 mg/l and the lowest one of -0.0004 mg/l. The highest concentration of zinc (Zn) is 0.0228 mg/l and the lowest one is 0.0020 mg/l. The highest electrical conductivity of water in the five point is 31.8 μmho/cm and the lowest one is 28.3 μmho/cm. The highest water density in five point is 1095.9 kg/m3 and the lowest one is 1031 kg/m3.
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    Model Distribusi Panas Saluran Gas Buangan Kendaraan Untuk Optimalisasi Elemen Peltier Sebagai Generator Termal
    (2015-10-26) Tambunan, Walfred; Defrianto; Hamzah, Yanuar; Umar, Lazuardi
    Model distribusi panas saluran buangan kendaran bermotor telah dikembangkan untuk optimalisasi generator termoelektrik. Modul termoelektrik (thermal electric modules, TEMs) memanfaatkan efek Seebeck untuk membangkitkan listrik dari perbedaan gradien suhu, yang banyak dipergunakan bidang otomotif sebagai penghasil energi. Paper ini menyajikan suatu model matematis dipergunakan untuk mensimulasikan distribusi panas pada knalpot automotive dan untuk mereduksi kompling termal antara elemen Peltier dan sumber panas sesuai dengan bentuk dan geometri sumber dan serta elemen. Distribusi suhu pada model ditentukan dengan komputasi dimana model dibagi menjadi m pada arah sumbu x dan sumbu y pada arah n, menggunakan pemograman Matlab. Persamaan diskritisasi mensimulasikan distribusi suhu pada model generator termoelektrik pada nilai panjang penyangga aluminium La = 5, 7.5, 10, 15 dan 20 mm pada suhu sumber sebesar 120°C. Hasil model memperlihatkan variasi penurunan suhu dan dipergunakan untuk memilih lapisan pelapis dinding knalpot gas buangan untuk memastikan distribusi panas yang tepat dari TEM
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    Model Distribusi Panas Saluran Gas Buangan Kendaraan Untuk Optimalisasi Elemen Peltier Sebagai Generator Termal
    (2015-12-17) Tambunan, Walfred; Defrianto; Umar, Lazuardi; Hamzah, Yanuar
    Model distribusi panas saluran buangan kendaran bermotor telah dikembangkan untuk optimalisasi generator termoelektrik. Modul termoelektrik (thermal electric modules, TEMs) memanfaatkan efek Seebeck untuk membangkitkan listrik dari perbedaan gradien suhu, yang banyak dipergunakan bidang otomotif sebagai penghasil energi. Paper ini menyajikan suatu model matematis dipergunakan untuk mensimulasikan distribusi panas pada knalpot automotive dan untuk mereduksi kompling termal antara elemen Peltier dan sumber panas sesuai dengan bentuk dan geometri sumber dan serta elemen. Distribusi suhu pada model ditentukan dengan komputasi dimana model dibagi menjadi m pada arah sumbu x dan sumbu y pada arah n, menggunakan pemograman Matlab. Persamaan diskritisasi mensimulasikan distribusi suhu pada model generator termoelektrik pada nilai panjang penyangga aluminium La = 5, 7.5, 10, 15 dan 20 mm pada suhu sumber sebesar 120°C. Hasil model memperlihatkan variasi penurunan suhu dan dipergunakan untuk memilih lapisan pelapis dinding knalpot gas buangan untuk memastikan distribusi panas yang tepat dari TEM
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    PENENTUAN KOEFISIEN ABSORPSI GELOMBANG BUNYI DARI KERTAS KARDUS
    (2013-03-05) Siregar, Wahyuddin; Emrinaldi, Tengku; Tambunan, Walfred
    A study concerning the absorption of acoustic waves using acoustic panels made from corrugated paper. In this study about absorption of acoustic waves has been carried out by measuring the sound absorption coefficient using corrugated paper as raw material for acoustic panels. The study was conducted by direct measurement in the laboratory using acoustic instruments and measurements obtained from the value level of intensity and level of initial intensity after passing through the material, then the data is equalized using a comparison between the level of intensity of the sound absorbed by the level of intensity of sound that arrives at the surface of the material using Excel and SPSS program to get the value of sound absorption coefficient on the tested material. Material thicknesses used are 0.5 cm to 2 cm, while the frequencies used are 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz. Based on these results, it can be concluded that the highest coefficient was 0.37 and the lowest result was 0.04 which each value coefficient is related to frequency of 2000 Hz with a thickness of 1 cm and a frequency of 125 Hz with a thickness of 0.5 cm
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    PENENTUAN KONSENTRASI LOGAM BERAT Pb, Cu, Zn DAN KONDUKTIVITAS LISTRIK LIMBAH CAIR INDUSTRI PABRIK KARET PEKANBARU
    (2014-03-26) Mardhatillah, Wirdati; Syech, Riad; Tambunan, Walfred
    A research has been done about the determination of heavy metal concentrations such as Pb, Cu, Zn and electrical conductivities of industrial liquid waste of some rubber factories in Pekanbaru. The method that used in this research was an experimental method while the samples of rubber factory waste in Pekanbaru were taken five times for each rubber factory. The waste samples then were measured their heavy metal concentration using an Atomic Absorbtion Spectophotometer (AAS) and their electrical conductivity was measured by an conductivitimeter. The result showed that the concentration of Pb from both samples was not detected, this indicates that the concentration of Pb was very small. The average concentration of Zn in the liquid waste of PT. Bangkinang was 7,436 x10-6 kg/L which was higher than the of Zn concentration in liquid waste of PT. RICRY which was 3,59 x10-6 kg/L. The aveage concentration of Cu in liquid waste of PT. Bangkinang was 1,49 x10-6 kg/L that was higher than the Cu concentration in liquid waste of PT. RICRY which was 1,436 x10-6 kg/L. The average of electrical conductivity in liquid waste of a rubber factory, PT. Bangkinang was 319,74 x10-4 mho/m which was higher than of of liquid waste of PT. RICRY which was only 197,92 x10-4 mho/m
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    RANCANG BANGUN SISTEM PENYULINGAN AIR GAMBUT DENGAN ENERGI MATAHARI MENGGUNAKAN KOLEKTOR SENG BERGELOMBANG
    (2016-02-01) Nanda, Rio Saputra; Syech, Riad; Tambunan, Walfred
    A peat water distillation using corrugated zinc plate collectors, by comparing the clean water produced by solar energy, water filter with different types of angles is investigated experimentaly. This tool serves as a modifier peat water into clean water that can be reused everyday, by evaporating water using solar energy peat for clean water. Water filter using solar energy can be seen from a slope angle 30° and has more clean water at the a slope angle of 45 °, which 2255 ml to 1645 ml corresponding to angle of 30° and 45° cespectively This is due to the angle of 30° having more sunny light into space refiners compared with a the angle 45°. The temperature inside the chamber refiners tool is also varied. Maximum temperature on the tool refiners with a slope angle 30o is higher than the maximum temperature distillation apparatus with a slope angle 45° . This also corresponds to 68oC with angle of 30o and 65oC with angle of 45o while the surrounding temperature reaches 42oC
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    STUDI PERUBAHAN ENERGI MATAHARI MENJADI ENERGI LISTRIK DENGAN MENGGUNAKAN SEL SILIKON DIODA SILINDER
    (2016-02-01) Oriza, Purnama; Tambunan, Walfred; Sugianto
    The study of solar energy conversion to electrical energy by using silicon diode in cylindrical cells has been experimentally investigated. Silicon cells is connected to series and parallel for each 25 and 50 diode with glass and no glass plate respectively. The measurement is conducted by voltage and ampere meter to show the change of voltage and current. The intensity of sun light and heat uses Lux meter and thermometer in 10 minutes interval from 10.00 Wibb until 13.00 Wibb for 6 days. The results show that the lowest average intensity is 35.56 K lux (at 10.00 Wibb) and the biggest average intensity is 108.30 K lux (at 13.00 Wibb). For 25 diodes the results are as follows. The minimum current (series, with glass plate) is 21.33 μA at 11.50 Wibb. The maximum current (parallel, with no glass) is 1027 μA at 12.50 Wibb.The minimum voltage (parallel, with glass plate) is 223 mV at 11.00 Wibb. The maximum voltage (series, with no glass) is 7.033 V at 12.50 Wibb. For 50 diodes the results are as follows. The minimum current ( series, with glass plate ) is 21.33 μA at 11.50 Wibb. The maximum current (parallel, with no glass) is 2037 μA at 12.50 Wibb. The minimum voltage (parallel, with glass plate) is 232.30 mV at 11.00 Wibb. The maximum voltage (series, with no glass) is 12.50 V at 12.50 Wibb.