Posman Manurung
Department of Physics, University of Lampung, Jl. Prof. Soemantri Brodjonegoro No. 1 Bandar Lampung 35145

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Sifat Fisis Komposit Pe/Nanosilika sebagai Fungsi Ketebalan Sari, Tria Permata; Manurung, Posman; Riyanto, Agus
Jurnal Teori dan Aplikasi Fisika Vol 7, No 1 (2019): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v7i1.1934

Abstract

Polyethylene (PE) has been widely used as the insulation material of high voltage cables because of its outstanding physical, chemical, and electrical properties. In this research the amorph nanosilica powders were extracted from pumice using NaOH, H2SO4 and HCl. PE and nanosilica was mixed by mixer at temperature 95 OC and then made the film by using barcoater. The weight percentage of nanosilica was 5 and 10% with thickness of 6, 12 and 25μm respectively. The PE/nanosilica were characterized via Fourier Transform InfraRed (FTIR) spectroscopy and LCR measurement to abtain conductivity and permitivity respons as a function of frequency. The effect thickness on the electrical properties of PE/nanosilica of 5 and 10 % for conductivity values in samples 25 μm thick has a greater conductivity value. Whereas for the electrica constant of two filer variation shows that the thicker the sample, the greater the electric constant value. Where as for the dielectric constant of two filler variations shows that the ticker the sample, the greater the electric constant value.
Analisis dan Karakterisasi Kandungan Silika (SiO2) sebagai Hasil Ekstraksi Batu Apung (Pumice) Trianasari, Trianasari; Manurung, Posman; Karo Karo, Pulung
Jurnal Teori dan Aplikasi Fisika Vol 5, No 2 (2017): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v5i2.1814

Abstract

The study of silica from pumice was done by extraction method using NaOH, H2SO4, and HCl. Powder of pumice before extraction was calcined at 450oC for 4 hours. The extraction powder was calcined at 800 °C for 3 hours. The powder before and after the extraction were characterized by XRD and SEM-EDS. Sample also characterized by DTA-TGA analysis before extraction and after extraction was analyzed by TEM. XRD pattern powder of pumice dominated by amorphous silica. The results have been confirmed with SEM-EDS showing that the silica content has the highest percentage, ie 65.88% for the sample before extraction and 78.95% for the sample after extraction. From the TEM observation it shows spherical particles, with particle size of 5.8 ± 0.2 nm. DTA-TGA analysis for pumice powder shows the occurrence of endotherm and exothermic events accompanied by mass shrinkage along with warming temperature rise.
Analisis Termal-hidrolik Reaktor Cepat Berpendingin Gas (Gas Cooled Fast Reactor) Menggunakan Metode Runge Kutta Anggraini, Adeliya Ayu; Yulianti, Yanti; Manurung, Posman
Jurnal Teori dan Aplikasi Fisika Vol 6, No 2 (2018): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v6i2.1913

Abstract

The Research of Gas Cooled Fast Reactor (GCFR) thermal-hydraulics analysis has been done. This reseacrh aim to solve fuel rod heat conduction equation by Runge Kutta method and to get thermal-hydraulics parameters such as coolant axial temperature distribution, pressure drops, convection heat transfer coefficient, and fuel rod radial temperature distribution. Heat transfer of the reactors was assumted steady state (time independent) then obtained coolant inlet tempertaure about 450 oC, outlet temperature about 474,752 oC and convection heat transfer coefficient   about 2,5903 W/cm2 oC. Pressure drop by friction was 0,16968 bar, pressure drop by form was 0,31292 bar, pressure drop by gravity was 0,20580 bar and total pressure drop was 0,68838 bar. While centerline fuel obtained the maximum temperature of fuel rod about 2720,33812 oC and the lowest fuel rod temperature at cladding surface about 488,8205 oC.
Variasi Kadar CaCO3 Terhadap Pertumbuhan Fasa Suoperkonduktor BPSCCO-2223 Menggunakan Metode Pencampuran Basah Suprihatin, Suprihatin; Manurung, Posman; Wijaya, Ketut Putra
JASIEK (Jurnal Aplikasi Sains, Informasi, Elektronika dan Komputer) Vol 2, No 1 (2020)
Publisher : Universitas Merdeka Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26905/jasiek.v2i1.3632

Abstract

Telah dilakukan penelitian tentang pengaruh kadar CaCO3 terhadap pertumbuhan fasa BPSCCO-2223 menggunakan metode pencampuran basah dengan memvariasikan kadar Ca. Sintesis dilakukan dengan melarutkan sampel menggunakan HNO3 dan aquades secara perlahan kemudian dilakukan pengeringan pada suhu 300, 400, dan 600 ℃ secara bertahap. Sampel dikalsinasi selama 10 jam  pada suhu  800 ℃ dan disintering pada suhu 865℃ selama 10 jam. Hasil sintesis superkonduktor dikarakterisasi menggunakan XRD, SEM  dan uji Meissner. Hasil XRD menunjukkan  bahwa penambahan kadar Ca berpengaruh terhadap tingkat kemurnian fasa superkonduktor BPSCCO-2223. Pada penelitian ini, kadar Ca yang optimum yaitu Ca 2,05 mol dengan  nilai fraksi volume (Fv) sebesar 79,98%. Sedangkan fraksi volume terendah adalah Ca 1,95 mol sebesar 41,27%. Derajat orientasi yang relatif tinggi terdapat pada sampel Ca 2,10 mol sebesar 7,67% dan terendah terdapat pada Ca 1,95 mol sebesar 0%. Hasil SEM menunjukkan bahwa semua sampel telah memiliki lapisan-lapisan yang tersusun (terorientasi) dengan ruang kosong antara lempengan (void) relatif kecil. Hasil uji-Meissner menunjukkan bahwa Ca 2,05 mol mengalami efek Meissner lemah, sedangkan sampel BPSCCO-2223 yang lain tidak menunjukkan adanya efek Meissner dalam nitrogen cair    (77 K).Kata Kunci : BPSCCO-2223, Derajat Orientasi, Fraksi Volume, Superkonduktor, Uji-Meissner