Walfred Tambunan
Department Physics: FMIPA - Universitas of Riau

Published : 13 Documents
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EFEK ADITIF Bi2O3 TERHADAP MIKROSTRUKTUR DAN KOEFISIEN NON LINEAR VARISTOR ZnO. Tambunan, Walfred; Malik, Usman
2302-0792
Publisher : Edu Research

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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 ofnon linier () and it can give influence correlation betweencurrent I and voltage V. The mixing process of raw materialswas done by using magnetic stirrer and liquid acetone asmedia, and then was dried at 60oC, and also grinded untilpassing 400 meshes. Pellet was made by using pressing 50MPa, and fired at 1050oC with holding time 2 hours. Afterfiring, all samples are characterized, such as: measurement ofcoefficient of non linier (), and observation of microstructureby using Scanning Electron Microscope (SEM). The resultsshow that sample without additive has  less than 5 and thissample has not properties as varistor, but the highest value of is 64 for sample with additive 7.5% Bi2O3. The result ofphotos SEM shows that the increase of percentage of additiveBi2O3 can influence of formation grain boundary and grainsize. Where, value of coefficient of non linier () is depend onexisting of grain boundary and thickness of grain boundary.
PENENTUAN KONDUKTIVITAS LISTRIK DAN KAJIAN KUALITAS AIR SUNGAI SIAK MENGGUNAKAN METODE JEMBATAN WHEATSTONE Aritonang, Alan Perdana; Syech, Riad; Tambunan, Walfred
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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A research has  been done on  the determination of the electrical conductivity and  water quality  of Siak River water  using a Wheatstone bridge method  in   the  location around the rubber factory   of PT. RICRY. The research was begun by taking samples  of the Siak river water were taken on  five  points  which  have been determined at a distance of 10 meters from PT. RICRY when was low  and high  tide. Based on the  length  data  of wire L1  and L1,  it  could  be determined  the value of electrical resistance, resistivity  and electrical conductivity. The result showed that the value of  highest  electrical conductivity of the river  water  when the  sea  water was  at  high tide  was  58,513  .  10-6 (Ωm)-1, while the electrical conductivity of  the river  water at low tide  was 41,879  . 10-6 (Ωm)-1. A decent water for consumption has an  electrical conductivity of (300  -500).106(Ωm)-1(Mailinda, U. 2011). Based on  that  standard  electrical conductivity, Siak river  water  in  the  research location when the sea water  high tide and low tide are not worthy to be consumed because  of  too small  value  compared  to  the standard   value of electrical conductivity .
Analisa Karakteristik Alat Pemanas Air dengan menggunakan Kolektor Palung Parabola Tambunan, Walfred; Ginting, Maksi; Surbakti, Antonius
Komunikasi Fisika Indonesia Vol 12, No 10 (2015)
Publisher : Komunikasi Fisika Indonesia

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Telah dilakukan penelitian analisa karakteristik alat pemanas air dengan menggunakan kolektor palung parabola. Penelitian dilakukan dengan cara menempatkan kolektor palungan ditempat terbuka dimana sinar matahari jatuh secara langsungkemudiandengan menggunakan pipa aluminium air dialirkan sepanjang garis fokus kolektor palungan lalu setiap 60 menit air yang telah melewati kolektor palungan ditampung dan diamati temperaturnya. Hasil yang diperoleh menunjukkan bahwa temperatur kolektor tertingi rata-rata adalah 50,03 OC dengan temperatur rata-rata air pada bak penampung sebesar 40,070C pada pukul 13.00 WIB sedangkan temperatur kolektor terendah rata-rata adalah 39,140C dengan temperatur rata-rata air pada bak penampung sebesar 35,28 0C pada saat pukul 10.00. Temperatur air tertinggi rata-rata pada pukul 13.00 WIB inidisebabkan karena pada waktu tersebut intensitas radiasi matahari mencapai harga maksimum. Laju kalor yang hilang secara konduksi tertinggi rata-rata 29,05 J/s pada pukul 13.00 WIB sedangkan laju kalor yang hilang secara konduksi terendah rata-rata sebesar 16,85 J/s pada pukul 10.00 WIB. Volume air yang dihasilkan rata-rata sebanyak 38 liter dalam sehari selama 6 jam dari pukul 09.00 WIB sampai pikul 15.00 WIB. Hasil eksperimen secara keseluruhan menunjukkan karakteristik alat pemanas air dengan menggunakan kolektor bentuk palungan ini mempunyai sifat bahwa semangkin tinggi intensitas radiasi matahari yang jatuh pada permukaan kolektor semangkin tinggi pula temperatur air yang dipanaskan. Kata kunci: pemanas air, kolektor palungan, energi matahari
PENGEMBANGAN DAN OPTIMALISASI ELEMEN PELTIER SEBAGAI GENERATOR TERMAL MEMANFAATKAN ENERGI PANAS TERBUANG Tambunan, Walfred; Umar, Lazuardi; Fuji, Dara
Komunikasi Fisika Indonesia Vol 12, No 11 (2015)
Publisher : Komunikasi Fisika Indonesia

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The research is dones to examine the power of the peltier elements electricity .Electrical energy is needs for human beings , but excessive use will cause scarcity of electrical energy , so that required an attempt to find sustainable alternative energy .One of them is by making use of waste heat use peltier elements to be turned into electrical energy and applied to a thermoelectric power. TEG thermoelectric power (Thermoelectric Generator) can generate electrical energy when there is a temperature difference between two different semiconducting material, this principle known as the "Seebeck effect" which is the opposite of the Peltier effect TEC (Termoelectric Cooling), where the voltage variation from toroid transformater on the heater as a simulation of waste heat in vehicles by 10 volts each interval increment from 30 volts to 80 volts along 40 minutes. The test results showed the voltage depends on the temperature difference between the hot and cold sides. Where the voltage is directly proportional to the temperature difference of peltier elements, as well as the current and power generated. Research on this TEG has a bright prospect for the future as a source of electrical energy.Keywords : Peltier elements, Seebeck effect, Thermoelectric generator
RANCANG BANGUN SISTEM DETEKSI POLA FRINJI UNTUK INTERFEROMETER MICHELSON Buanti, Eka; ', Minarni; Tambunan, Walfred
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Instrument used to precisely measure the wavelength of a laser light is known as a wavemeter. One of very important wavemeter parts is a fringe counting circuit. In this research a fringe counting circuit has been built and characterized using a Michelson Interferometer. The circuit system contained three parts i.e a current to voltage converter circuit for a photodiode, a TTL converter circuit, and a counting circuit. The circuits were characterized using two He-Ne laser with two different laser powers 1 mW and 5 mW which were used as the light source for a Pasco Michelson Interferometer. Two photodiodes with two different sensitive areas 100 mm2 and 7.5 mm2 were used. The research results showed that 1 mW Pudak He Ne laser resulted 2 µA for dark fringe and 8 µA for bright fringe when using 7.5 mm2 photodiode active area, then 3 µA for dark fringe and 400 µA for bright fringe when using 100 mm2 photodiode. The results for Meredith He Ne laser resulted 2 µA for dark fringe and 14 µA for bright fringe when using 7.5 mm2 photodiode, then 50 µA for dark fringe and 8000 µA for bright fringe when using 100 mm2 photodiode. The I toV converter which was designed produced voltage bigger than 5 V when using 100 mm2 photodiode. The counter circuit resulted 3.2 V TTL signal output for 200 mV TTL signal input with the same frequency.
EFEK ADITIF Bi2O3 TERHADAP MIKROSTRUKTUR DAN KOEFISIEN NON LINEAR VARISTOR ZnO. Tambunan, Walfred; Malik, Usman
Jurnal Edu Research Vol 1, No 2 (2012): Jurnal Pendidikan
Publisher : Universitas Pasir Pengaraian

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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.
SIMULASI 3 DIMENSI DISTRIBUSI PANAS PLAT KNALPOT MOBIL UNTUK ELEMEN TERMOELEKTRIK Adli, Wildan; Tambunan, Walfred; Umar, Lazuardi
Komunikasi Fisika Indonesia Vol 13, No 12 (2016)
Publisher : Komunikasi Fisika Indonesia

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This study simulates the distribution of heat in the conductor plate micro energy generation based module Thermoelectric Generator (TEG) type 40-40-10 / 100 to optimize the absorption of heat from the vehicle exhaust waste heat. The module has a maximum operating temperature of 423K. The modeling is done using MATLAB with a modified diffusion equation by application of 900K of temperature as boundary condition on the surface of the base plate which is in contact with the heat source. The plate with aluminum material modeled in varies form of solid, hollow, hollow gitter, hollow heatsink, with dimensions of 110mm long, 60mm wide, 30mm thick base and 30mm thick bulge. The best temperature drop obtained for ΔT = 178,67K (19.85%) produced by the shape of a hollow heatsink plate. The resulting temperature of this model is then lowered back with varying types of material such as aluminum, copper, iron, and stainless steel, as well as by varying the number of TEG array that is 1 to 4-arrays, each array consisting of two modules. Drop in temperature that comes closest to the maximum TEG operating temperature is a drop in temperature that generates the final temperature of 402K, which comes from hollow-with-heatsink stainless steel plate with 50mm of thick and 4-arrays formation.
PENGARUH PENAMBAHAN FRIT GELAS TERHADAP KARAKTERISTIKDIELEKTRIK KAPASITOR KERAMIK FILM TEBAL BATIO3 Tambunan, Walfred; Surbakti, Antonius; Syarif, Dani Gustaman
Komunikasi Fisika Indonesia Vol 13, No 13 (2016)
Publisher : Universitas Riau

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Thick film dielectric ceramic capacitors have been manufacture with an additive mixture ofBaTiO3 95 % : 5 % , 92.5 % : 7.5 % and 90 % : 10 % regarding the frits glass weight. Themixedsamples to the forms of pasta by adding 20%organic compounds heaviness. Formedpasta from the three types of samples sintered at a temperature of 700 C for 20 minutes.Then the characteristics of the sample by using XRD, SEM and LCR metersis done. XRDresults identified that all three types of samples formed BaTiO3 phase with a tetragonalcrystal structure that the length of the crystal grid is a = b ≠ c and angles α = β = γ . Theresults of SEM analysis showed BaTiO3 thick film microstructure changes by indicated theincrease in grain. Dielectric characteristics by measuring the capacitance of a capacitor attemperature of 30C - 100C. The results turned be a thick film capacitors with 5% fritcomposition has a dielectric constant of 230.75, 7.5% frit composition has a dielectricconstant of 39.58% and 10% frit composition has dielectric constant of 293.87% attemperature of 100C. These three dielectric constantvalues indicated 10% frit composition isthe highest dielectric constant of the capacitor and is the best of the three types of capacitor .
SIMULASI 3 DIMENSI DISTRIBUSI PANAS PLAT KNALPOT MOBIL UNTUK ELEMEN TERMOELEKTRIK Adli, Wildan; Tambunan, Walfred; Umar, Lazuardi
Komunikasi Fisika Indonesia Vol 13, No 12 (2016)
Publisher : Universitas Riau

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Abstract

This study simulates the distribution of heat in the conductor plate micro energy generation based module Thermoelectric Generator (TEG) type 40-40-10 / 100 to optimize the absorption of heat from the vehicle exhaust waste heat. The module has a maximum operating temperature of 423K. The modeling is done using MATLAB with a modified diffusion equation by application of 900K of temperature as boundary condition on the surface of the base plate which is in contact with the heat source. The plate with aluminum material modeled in varies form of solid, hollow, hollow gitter, hollow heatsink, with dimensions of 110mm long, 60mm wide, 30mm thick base and 30mm thick bulge. The best temperature drop obtained for ΔT = 178,67K (19.85%) produced by the shape of a hollow heatsink plate. The resulting temperature of this model is then lowered back with varying types of material such as aluminum, copper, iron, and stainless steel, as well as by varying the number of TEG array that is 1 to 4-arrays, each array consisting of two modules. Drop in temperature that comes closest to the maximum TEG operating temperature is a drop in temperature that generates the final temperature of 402K, which comes from hollow-with-heatsink stainless steel plate with 50mm of thick and 4-arrays formation.
Pengaruh Ketidakteraturan Domain pada Normal Mode dan Frekwensi Natural Pada Getaran Membran Defrianto, Defrianto; Tambunan, Walfred; Ginting, Maksi
Komunikasi Fisika Indonesia Vol 14, No 1 (2017)
Publisher : Universitas Riau

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Telah dilakukan penelitian untuk menentukan frakwensi natural dan normal mode getaran membranedengan luas 48 m2 berbentuk teratur 4 sisi, tidak teratur 8 dan 10 sisi. Frekwensi fundamental padanormal mode pertama untuk membrane 4, 8 dan 10 sisi berturut-turut yaitu 1.7129, 1.7503 dan 1.7973Hz. Frekwensi natural untuk mode yang sama menunjukkan semakin tidak teratur membrane akanmemberikan frekwensi natural yang semakin tinggi. Normal mode untuk setiap mode pada membrane4, 8 dan 10 sisi memberikan bentuk yang hampir sama.