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All Journal Indonesian Journal of Applied Sciences Jurnal Sains Materi Indonesia Jurnal Informatika dan Teknik Elektro Terapan Jurnal Zeolit Indonesia Jurnal Ilmiah Teknologi Pertanian Agrotechno Chimica et Natura Acta Indonesian Mining Journal JOURNAL OF SCIENCE AND SOCIAL RESEARCH Money: Journal of Financial and Islamic Banking Journal of Technology Informatics and Engineering Prosiding Seminar Nasional Pengabdian kepada Masyarakat (SINAPMAS) Indonesian Mining Journal
Juliandri Juliandri
Department Of Chemistry Faculty Of Mathematics & Natural Science Padjadjaran University Jalan Raya Bandung Sumedang Km. 21 Phone/Fax. (+6222) 7794391
Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Energy Engineering Environmental Science Materials Science & Nanotechnology Social Sciences

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IMPROVEMENT REFRACTORY QUALITY OF ALUMINA SILICATE FOR BRASS SMELTING WITH INFILTRATION TECHNIQUE Irwansyah, Ferli S.; Juliandri, Juliandri; Hastiawan, Iwan; Rahardjo, Soewanto; Septawendar, Rifki
Jurnal Zeolit Indonesia Vol 9, No 1 (2010)
Publisher : Jurnal Zeolit Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (144.935 KB)

Abstract

Requirement of refractory materials for manufacturing industry and metal smelting is increasing along technology development. Brass smelting needs a larger size ceramic crucible which is known by the name “kowi”. Therefore, it needed a refractory material from local raw materials are higher quality, which has a low porosity, high density, and high mechanical strength. In this study was conducted increasing refractory quality of alumina silicate as a material for manufacturing a brass smelting kowi by infiltration technique. The raw materials such as kaolin, alumina, and magnesium oxide that has been determinate composition were brooded, printed, half-baked burned, infiltrated with a various concentrations, and then burned again, physical and chemical characteristic testing, and also used a Scanning Electron Microscope (SEM) to show morphology of refractory alumina silicate that have been infiltrated. The result showed that refractory alumina silicate was increase the qualities with porosity value of 11,36%, density value of 2,34 kg/m3, water absorbent of 4,85%, and mechanical strength of 129,072 kg/cm2 which can be used as “kowi” material for brass smelting industry.
PEMISAHAN LANTHANUM DARI LIMBAH HASIL PENGOLAHAN TIMAH DENGAN MENGGUNAKAN METODE PENGENDAPAN BERTINGKAT Hastiawan, Iwan; Firmansyah, Fajar; Juliandri, Juliandri; Eddy, Diana Rakhmawaty; Noviyanti, Atiek Rostika
Chimica et Natura Acta Vol 4, No 2 (2016)
Publisher : Departemen Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (118.439 KB) | DOI: 10.24198/cna.v4.n2.10678

Abstract

Di Indonesia mineral  mengandung unsur tanah jarang terdapat di dalam mineral bawaan pada komoditas utama terutama emas dan timah. Unsur tanah jarang sesuai namanya merupakan unsur yang langka, di alam berupa senyawa kompleks fospat dan karbonat. Lanthanum merupakan unsur dengan nomor atom 57 dan termasuk dalam golongan unsur tanah jarang ringan. Lanthanum oksida digunakan secara ekstensif pada aplikasi lampu karbon, terutama di industri perfilman untuk lampu studio dan proyeksi. Tujuan penelitian ini adalah mengetahui kadar lanthanum oksida yang diperoleh dari hasil pemisahan dengan menggunakan metode pengendapan bertingkat. Langkah pertama adalah destruksi dengan menggunakan natrium hidroksida. Lalu pembentukan tanah jarang klorida dengan penambahan asam klorida. Selanjutnya pengendapan selektif  untuk memisahkan tanah jarang hidroksida. Kemudian pemisahan lanthanum  dengan cara pengendapan bertingkat menggunakan ammonium hidroksida. Pengendapan dilakukan dalam  tingkatan pH yang berbeda. Lantanum hidroksida dilarutkan dengan asam nitrat untuk kemudian diendapkan dengan penambahan asam oksalat. Selanjutnya dilakukan kalsinasi pada suhu 1000°C selama 2 jam untuk pembentukan lanthanum oksida. Lanthanum oksida dianalisis dengan menggunakan SEM-EDX. Hasil karakterisasi SEM-EDX menunjukkan bahwa lanthanum oksida yang diperoleh dengan menggunakan metode pengendapan bertingkat mempunyai kadar sebesar 86,59%. Efisiensi dari metode pengendapan bertingkat dengan menggunakan ammonium hidroksida sebesar 64,57%.
CHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD Sanjaya, Rochmad K; Juliandri, Juliandri; Rahayu, Iman; Ismillayli, Nurul; hermanto, dhony
Jurnal Sains Materi Indonesia Vol 21, No 2: JANUARY 2020
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (916.989 KB) | DOI: 10.17146/jsmi.2020.21.2.5582

Abstract

CHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD. An exsitu method has been developed to performance of Nafion's membrane in PEMFC (Proton Electrolyt Membrane Fuel Cells), caused by the chemical degradation of ·OH and ∙H radicals. The change of the chemical structure occurring during the degradation were primarily calculated of the relative energy of reactions by DFT (Density Functional Theory) method approach in the Gaussian software. This study aims to determine whether DFT method with functional B3LYP, PBEPBE, and B3PW91 and base sets 6-311++G can be used in determining the relative energy of a reaction and knowing the difference in role between ·OH and ∙H in the degradation process of the main chain Nafion with the final group are -CF2H, -CF=CF2 and -COOH. The three functionalities applied showed that the ·OH radical has more role than the ∙H radical in the degradation process of the Nafion main chain. In the -CF2H group was shown the relative energy value of reaction 2 is lower than reaction 5, in the -CF=CF2 group was shown the relative energy value of reaction 8* is lower than reaction 11 and in the -COOH group the relative energ value of reaction 14 is lower than reaction 16. By knowing the relative energy of the Nafion main chain degradation reaction with a certain final group and the role of certain radical compounds in the degradation process, the DFT method with functional B3LYP, PBEPBE and B3PW91 and base sets 6-311++G can recommend various modifications of the Nafion as a fuel cell membrane, particularly in increasing of membrane performance.
PEMISAHAN LANTHANUM DARI LIMBAH HASIL PENGOLAHAN TIMAH DENGAN MENGGUNAKAN METODE PENGENDAPAN BERTINGKAT Iwan Hastiawan; Fajar Firmansyah; Juliandri Juliandri; Diana Rakhmawaty Eddy; Atiek Rostika Noviyanti
Chimica et Natura Acta Vol 4, No 2 (2016)
Publisher : Departemen Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (118.439 KB) | DOI: 10.24198/cna.v4.n2.10678

Abstract

Di Indonesia mineral  mengandung unsur tanah jarang terdapat di dalam mineral bawaan pada komoditas utama terutama emas dan timah. Unsur tanah jarang sesuai namanya merupakan unsur yang langka, di alam berupa senyawa kompleks fospat dan karbonat. Lanthanum merupakan unsur dengan nomor atom 57 dan termasuk dalam golongan unsur tanah jarang ringan. Lanthanum oksida digunakan secara ekstensif pada aplikasi lampu karbon, terutama di industri perfilman untuk lampu studio dan proyeksi. Tujuan penelitian ini adalah mengetahui kadar lanthanum oksida yang diperoleh dari hasil pemisahan dengan menggunakan metode pengendapan bertingkat. Langkah pertama adalah destruksi dengan menggunakan natrium hidroksida. Lalu pembentukan tanah jarang klorida dengan penambahan asam klorida. Selanjutnya pengendapan selektif  untuk memisahkan tanah jarang hidroksida. Kemudian pemisahan lanthanum  dengan cara pengendapan bertingkat menggunakan ammonium hidroksida. Pengendapan dilakukan dalam  tingkatan pH yang berbeda. Lantanum hidroksida dilarutkan dengan asam nitrat untuk kemudian diendapkan dengan penambahan asam oksalat. Selanjutnya dilakukan kalsinasi pada suhu 1000°C selama 2 jam untuk pembentukan lanthanum oksida. Lanthanum oksida dianalisis dengan menggunakan SEM-EDX. Hasil karakterisasi SEM-EDX menunjukkan bahwa lanthanum oksida yang diperoleh dengan menggunakan metode pengendapan bertingkat mempunyai kadar sebesar 86,59%. Efisiensi dari metode pengendapan bertingkat dengan menggunakan ammonium hidroksida sebesar 64,57%.
PENENTUAN GEOMETRI DAN KARAKTERISTIK IKATANSENYAWA KOMPLEKS NI(II)-DIBUTILDITIOKARBAMAT DENGAN METODE DENSITY FUNCTIONAL THEORY N.T. PONGAJOW; JULIANDRI JULIANDRI; IWAN HASTIAWAN
Indonesian Journal of Applied Sciences Vol 3, No 2 (2013)
Publisher : Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3623.703 KB) | DOI: 10.24198/.v3i2.16834

Abstract

PENENTUAN GEOMETRI DAN KARAKTERISTIK IKATAN SENYAWA KOMPLEKS NI(II)-DIBUTILDITIOKARBAMAT DENGAN METODE DENSITY FUNCTIONAL THEORY Nicolin Tirza Pongajow; Juliandri Juliandri; Iwan Hastiawan
Indonesian Journal of Applied Sciences Vol 7, No 2 (2017)
Publisher : Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (222.842 KB) | DOI: 10.24198/ijas.v7i2.2601

Abstract

AbstrakDensity Functional Theory (DFT) merupakan salah satu metode komputasi yang digunakan untuk perhitungan kimia. Metode ini dapat menyelesaian persamaan Schrödinger secara sederhana karena didasarkan pada densitas elektron. Dalam penelitian ini ditentukan geometri dan karaktersitik ikatan dari senyawa kompleks Ni(II)-dibutilditiokarbamat menggunakan metode DFT dengan fungsi B3LYP, B3PW91 dan BLYP. Basis set yang akan digunakan adalah LANL2DZ dan perangkat lunak Gaussian 03W. Hasil optimasi geometri Ni(II)-dibutilditiokarbamat menunjukkan bentuk struktur yang sama dengan Ni(II)-dietilditiokarbamat sebagai data pembanding, yaitu persegi planar. Keterisian elektron pada ikatan Ni – S adalah 1,8873 elektron, yang merupakan 20,24 % elektron dari Ni dan 79,76 % dari S. Bentuk geometri persergi planar dibuktikan dengan hasil analisis NBO yang menunjukkan hibridisasi Ni(II)-dibutilditiokarbamat adalah d1,05sp2.05. Kata kunci: DFT, dibutilditiokarbamat, geometri, karakteristik ikatan, senyawa kompleks. AbstractDensity Functional Theory (DFT) is one of computational method that used for chemical calculation. This method simplifies the complex solution of Schrödinger equation using electron density. In this study the geometry and bond characterization of Ni(II)-dibutyldithiocarbamat complex compound was determined. The computational method used was Density Functional Theory as applied in B3LYP, B3PW91 and BLYP functions. All calculations were performed at LANL2DZ level of basis set as implemented Gaussian 03W. The theoretical result on geometry showed a similar structure to square-planar Ni(II)-dietyldithiocarbamate. The electronic occupation of Ni–S molecular orbital was 1.8873 electron, which was 20.24% electron contribution from Ni and 79.76% from S. Square-planar geometry proved by NBO analysis result that the hybridization of Ni(II)-dibutyldithiocarbamate was d1,05sp2.05. Keywords: DFT, dibutyldithiocarbamate, geometry, bond characterization, complexes compound.
CHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD Rochmad K Sanjaya; Juliandri Juliandri; Iman Rahayu; Nurul Ismillayli; dhony hermanto
Jurnal Sains Materi Indonesia Vol 21, No 2: JANUARY 2020
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (916.989 KB) | DOI: 10.17146/jsmi.2020.21.2.5582

Abstract

CHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD. An exsitu method has been developed to performance of Nafion's membrane in PEMFC (Proton Electrolyt Membrane Fuel Cells), caused by the chemical degradation of ·OH and ∙H radicals. The change of the chemical structure occurring during the degradation were primarily calculated of the relative energy of reactions by DFT (Density Functional Theory) method approach in the Gaussian software. This study aims to determine whether DFT method with functional B3LYP, PBEPBE, and B3PW91 and base sets 6-311++G can be used in determining the relative energy of a reaction and knowing the difference in role between ·OH and ∙H in the degradation process of the main chain Nafion with the final group are -CF2H, -CF=CF2 and -COOH. The three functionalities applied showed that the ·OH radical has more role than the ∙H radical in the degradation process of the Nafion main chain. In the -CF2H group was shown the relative energy value of reaction 2 is lower than reaction 5, in the -CF=CF2 group was shown the relative energy value of reaction 8* is lower than reaction 11 and in the -COOH group the relative energ value of reaction 14 is lower than reaction 16. By knowing the relative energy of the Nafion main chain degradation reaction with a certain final group and the role of certain radical compounds in the degradation process, the DFT method with functional B3LYP, PBEPBE and B3PW91 and base sets 6-311++G can recommend various modifications of the Nafion as a fuel cell membrane, particularly in increasing of membrane performance.
IMPROVEMENT REFRACTORY QUALITY OF ALUMINA SILICATE FOR BRASS SMELTING WITH INFILTRATION TECHNIQUE Ferli S. Irwansyah; Juliandri Juliandri; Iwan Hastiawan; Soewanto Rahardjo; Rifki Septawendar
Jurnal Zeolit Indonesia Vol. 9 No. 1 (2010)
Publisher : Jurnal Zeolit Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Requirement of refractory materials for manufacturing industry and metal smelting is increasing along technology development. Brass smelting needs a larger size ceramic crucible which is known by the name "kowi". Therefore, it needed a refractory material from local raw materials are higher quality, which has a low porosity, high density, and high mechanical strength. In this study was conducted increasing refractory quality of alumina silicate as a material for manufacturing a brass smelting kowi by infiltration technique. The raw materials such as kaolin, alumina, and magnesium oxide that has been determinate composition were brooded, printed, half-baked burned, infiltrated with a various concentrations, and then burned again, physical and chemical characteristic testing, and also used a Scanning Electron Microscope (SEM) to show morphology of refractory alumina silicate that have been infiltrated. The result showed that refractory alumina silicate was increase the qualities with porosity value of 11,36%, density value of 2,34 kg/m3, water absorbent of 4,85%, and mechanical strength of 129,072 kg/cm2 which can be used as "kowi" material for brass smelting industry.
SYNTHESIS AND CHARACTERIZATION OF GAMMA ALUMINA AND ITS ADSORPTION CAPABILITY TEST FOR POMALAA MAGNESIUM LATERITE, SOUTHEAST SULAWESI Titin Siti Fatimah; Atiek Rostika Noviyanti; Juliandri Juliandri; Solihudin Solihudin
Indonesian Mining Journal Vol 22, No 1 (2019): INDONESIAN MINING JOURNAL, Vol. 22 No. 1, April 2019
Publisher : Puslitbang tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1748.461 KB) | DOI: 10.30556/imj.Vol22.No1.2019.977

Abstract

Based on variations in calcination temperature, gamma alumina has successfully been made using a simple sol-gel method for Pomalaa magnesium-laterite adsorption from the South East of Sulawesi. The laterite leached by sulfuric acid was then precipitated by ammonia, to make the magnesium was separated from its main impurities (Si, Fe and Al). Temperature variations at 500, 650, 800 and 950 °C in gamma alumina making formed the gamma alumina phase while the alpha alumina phase was formed at 1100 °C. The higher calcination temperature the lower the specific surface area respectively from 196.385, 156.239, 105.725, 96.134 and 15.396 (m2/g). This results in decreasing the magnesium of the laterite 9.04, 8.70, 8.09, 6.39 and 0.29 (mg/L) respectively. The 800 °C-calcination gamma alumina has the highest volume of the pore, namely 0.3265 mL/g and the radius of 61.76 Å. The gamma alumina isotherm curve is type IV. The SEM-EDS test shows an aggregation spherical shape. Gamma alumina was detected to adsorb Mg laterite. The X-ray mapping of SEM-EDS test shows even distribution between gamma alumina, magnesium and nickel. The highest adsorption is retained by GA-800/3 sample, namely 81.31 %.
Pengaruh Kadar Air dalam Minyak Kemiri Sunan pada Tahap Esterifikasi dengan Katalis Asam Sulfat Haryono Haryono; Juliandri Juliandri; Rustaman Rustaman
Jurnal Ilmiah Teknologi Pertanian Agrotechno Vol 8 No 2 (2023)
Publisher : Universitas Udayana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JITPA/2023.v08.i02.p06

Abstract

Kemiri sunan oil is non-food oil. Therefore, kemiri sunan oil can be a potential raw material for biodiesel synthesis. Kemiri sunan oil has relatively high free fatty acid content so that before the transesterification step with a homogeneous base catalyst it is necessary to esterify it first. In esterification, the water content in oil and fat as raw material for biodiesel affects the conversion rate of free fatty acids into biodiesel, so this needs to be studied. The purpose of this study was to study the effect of water content in kemiri sunan oil on the conversion of free fatty acids into biodiesel at the esterification stage. The research was conducted by quantitative experiment. Variations of water content in kemiri sunan oil were obtained through evaporation at a temperature of 105 oC with time variations of 1, 1.5 and 2 hours. Esterification was carried out at a temperature of 60 oC, mole ratio of oil to methanol of 1:6, reaction time of 1.5 hours, and 98% sulfuric acid catalyst as much as 1%. The results showed that the less water content in the kemiri sunan oil, the less free fatty acids contained in the biodiesel from the esterification result.
Co-Authors Arpizal Atiek Rostika Noviyanti Cindy Chintya Aulia Telaumbanua Dhony Hermanto Dian Kurnia Diana Rakhmawaty Eddy Eddy, Diana Rakhmawaty Fajar Firmansyah Ferli S. Irwansyah Ferli S. Irwansyah, Ferli S. Firmansyah, Fajar Harahap, Sahyunan Haryono Haryono Iman Rahayu Iwan Hastiawan Iwan Hastiawan IWAN HASTIAWAN Iwan Hastiawan Muhammad Fajar Muhammad Rizki N.T. PONGAJOW Nicolin Tirza Pongajow Nurul Ismillayli Rifki Septawendar Rifki Septawendar Rochmad K Sanjaya Rustaman Rustaman Sanjaya, Rochmad K Siahaan, Muhammad Donni Lesmana Siregar, Zailani Amir Soewanto Rahardjo Soewanto Rahardjo, Soewanto Solihudin Solihudin TATI NURHAYATI Titin Siti Fatimah Titin Siti Fatimah Wahyu, Wadri