Suprihatin Suprihatin
Universitas Lampung

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Efektivitas Ekstrak Daun Belimbing Wuluh (Averrhoa Bilimbi L.) Sebagai Inhibitor Pada Baja St37 Dalam Medium Korosif NaCl 3% Nia Aprilliani; Ediman Ginting Suka; Suprihatin Suprihatin
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.v5i2.1812

Abstract

The effectiveness of starfruitleaves extract as an inhibitor of St37 carbon steel in a corrosive medium of 3% NaCl had been researched. The concentration of starfruit leaves extract inhibitor was used 0%. 3%. 5% and 7% with immersion time of 4 and 8 days. Corrosion rate testing was done by weight loss method. The results of the research at each immersion time, showed that the optimum concentration of leaves starfruit extract to inhibit corrosion is 5% and the longer time immersion resulted in decreasing corrosion rate on St37 carbon steel. The maximum effectiveness of inhibitor occurred at 5% concentration with 8 days immersion time which is 78.57%. Characterization using Scanning Electron Microscopy (SEM) showed that the surface of steel looks smoother with white on sampleSt37-8-5 and St37-4-5 showing that tannin in starfruit leaves extract has been adsorbed on the steel surface while St37 carbon steel on St37-8-0 and St37-4-5 has a black steel surface with holes and cracks. Characterization using Energy Dispersive Spectroscopy (EDS) obtained oxygen element on sample St37-8-0 St37-4-0 greater concentration and Fe element smaller on sample St37-8-5 and St37-4-5.
Sintesis Superkonduktor BSCCO-2223 dengan Variasi Waktu Sintering pada Kadar Ca=2,10 Menggunakan Metode Pencampuran Basah Siti Istikomah; Suprihatin Suprihatin; Agus Riyanto
Jurnal Teori dan Aplikasi Fisika Vol 7, No 2 (2019): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v7i2.1980

Abstract

Research about the effect of sintering time on the phase purity level of superconductor BSCCO-2223 at the level of Ca 2,10 has been synthesized using the wet-mixing method. Sample dissolved is slowly with HNO3 and aquades, then drying gradually temperature of 300, 400, 600 °C. The sample was calcined for 10 hours at 800 °C and sintered using variations of time 10, 20, 30, and 40 hours at 865°C. Variations were carried out to determine the effect of sintering time on the purification of the superconductor. XRD results show that sintering time has an effect on the volume fraction value of BSCCO-2223. Volume fraction that is relatively high at  30 hours sintering time is 79,17 % with an orientation degree value of 37.94%. While the lowest was obtained at the time of sintering for 10 hours with the volume fraction of 38.47% with a degree of orientation of 15.27%. the SEM results show that all samples have layers oriented and have relatively little space between the plates (voids). 
Pengaruh Penambahan Inhibitor Ekstrak Kopi Dan Waktu Perendaman Terhadap Laju Korosi Pada Baja Karbon Aisi 1020 Dalam Larutan Nacl 3% Hartono Simanjuntak; Ediman Ginting; Suprihatin Suprihatin
Jurnal Teori dan Aplikasi Fisika Vol 7, No 2 (2019): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v7i2.2109

Abstract

Ekstrak kopi yang digunakan sebagai inhibitor pada sampel baja karbon AISI 1020, direndam dalam medium korosif NaCl 3%. Dengan memvariasikan waktu perendaman 4 hari dan 8 hari, dan juga konsentrasi inhibitor 0%, 3%, 5% dan 7%. Setelah perlakuan pada sampel diperoleh hasil perhitungan laju korosi yang paling lambat pada sampel AISI 1020 8.7 dan yang paling cepat pada sampel AISI 1020 4.0. Inhibitor yang digunakan mempunyai nilai efisiensi paling tinggi pada sampel AISI 1020 4.7. Hasil karakterisasi XRD menunjukkan bahwa struktur kristal yang terbentuk merupakan fasa Fe murni. Karakterisasi SEM menunjukkan morfologi permukaan sampel, terlihat gumpalan pada sampel. Karakterisasi EDS pada sampel terlihat unsur Oksigen (O) yang mengindikasikan bahwa sampel telah terkorosi.
Pengaruh Suhu Sintering Terhadap Tingkat Kemurnian Fase Superkonduktor BPSCCO-2223 pada Kadar Ca 2,10 Menggunakan Metode Pencampuran Basah Rizki Putri Surahman; Suprihatin Suprihatin; Agus Riyanto
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.v7i1.1926

Abstract

Sintering temperature has an effecton the purity level BPSCCO-2223 superconductor phase. This study has been conducted using the wet-mixing method with the materials used are Bi2O3, PbO, SrCO3, CaCO3, CuO, NHO3 and aquades. Synthesis carried out by slowly dissolving HNO3 and aquades then gradually for 40 hours dried out at a temperature of 300, 400, 600 °C. The sample was analysed with calcination for 10 hours at 800 °C and sintering for 20 hours using variations of temperature on each 850, 855, 860, and 865 °C. The XRD results show that phase purity which increases with increasing sintering temperature. The relative high volume fraction of the BPSCCO-2223-865 sample is 87,20% while, the lowest volume fraction of BPSCCO-2223-850 is 58,25%. The relative high orientation degree of BPSCCO-2223-855 is 27,64% and the lowest orientation degree of BPSCCO-2223-860 is 21,16%. The SEM result shows that all samples have layers arranged (oriented) by empty spaces between relatively small plaque (void).
Pengaruh waktu sintering Terhadap tingkat kemurnian fase Superkonduktor BPSCCO-2223 dengan Kadar Ca 2,10 Menggunakan Metode Pencampuran Basah Isnaini Rahayu; Suprihatin Suprihatin; Agus Riyanto
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.v7i1.1931

Abstract

Research about the effect of sintering time on the phase purity level of superconductor BPSCCO-2223 at the level of Ca 2,10 has been synthesized using the wet-mixing method. Synthesis carried out by slowly dissolving HNO3 and aquades then gradually for 40 hours dried out at a temperature of 300, 400, 600 °C. The sample was calcined for 10 hours at 800 °C and sintered using variations of time 10, 20, 30, and 40 hours at 865°C. Variations were carried out to determine the effect of sintering time on the purification of the superconductor. XRD result shows a decrease in phase purity with increasing the sintering time. Volume fraction that is relatively high at BPSCCO-2223/ts10 is 88,88%. While the lowest volume fraction of BPSCCO-2223/ts40 is 71,51%. The relative high orientation degree of BPSCCO-2223/ts30 is 33,76% and the lowest orientation degree of BPSCCO-2223/ts20 is 22,21%. The SEM result shows that all samples have layers arranged (oriented) by empty spaces between the plate (void) is relatively small.