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Characteristics of Vanadium Doped And Bamboo Activated Carbon Coated LiFePO4 And Its Performance For Lithium Ion Battery Cathode Sofyan, Nofrijon; Alfaruq, Subkhan; Zulfia, Anne; Subhan, Achmad
Jurnal Kimia dan Kemasan Vol. 40 No. 1 April 2018
Publisher : Balai Besar Kimia dan Kemasan

Vanadium doped and bamboo activated carbon coated lithium iron phosphate (LiFePO4) used for lithium ion battery cathode has been successfully prepared. Lithium iron phosphate was prepared through a wet chemical method followed by a hydrothermal process from the starting materials of LiOH, NH4H2PO4, and FeSO4.7H2O. The dopant variations of 0 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% of vanadium and a fixed 3 wt.% of bamboo activated carbon were carried out via a solid-state reaction process each by using NH4VO3 as a source of vanadium and carbon pyrolyzed from bamboo tree, respectively. The characterization was carried out using X-ray Diffraction (XRD) for the phase formed and its crystal structure, Scanning Electron Microscope (SEM) for the surface morphology, Electrochemical Impedance Spectroscopy (EIS) for the conductivity, and battery analyzer for the performance of lithium ion battery cathode. The XRD results show that the phase formed has an olivine based structure with an orthorhombic space group. Morphology examination revealed that the particle agglomeration decreased with the increasing level of vanadium concentrations. Conductivity test showed that the impedance of solid electrolyte interface decreased with the increase of vanadium concentration indicated by increasing conductivity of 1.25 x 10-5 S/cm, 2.02 x 10-5 S/cm, 4.37 x 10-5 S/cm, and 5.69 x 10-5 S/cm, each for 0 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% vanadium, respectively. Vanadium doping and bamboo activated carbon coating are promising candidate for improving lithium ion battery cathode as the initial charge and discharge capacity at 0.5C for LiFePO4/C at 7 wt.% vanadium is in the range of 8.0 mAh/g.

EFFECT OF SINTERING TEMPERATURE ON THE ROLLED COPPER-SHEATHED MONOFILAMENT MgB2 SUPERCONDUCTING WIRE Herbirowo, Satrio; Imaduddin, Agung; Sofyan, Nofrijon; Yuwono, A.H
Teknologi Indonesia Vol 40, No 1 (2017)
Publisher : LIPI Press

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The manufacture of low temperature superconductor (LTS) MgB2 with relatively high critical temperature (Tc = 39K) wire fabricated by powder-in-tube (PIT) is a multi-step process. The main difficulty is that the value of Tc superconductor wire is determined by various factors. MgB2 superconductor has been developed for possible utilization in various practical applications, such as Magnetic Resonance Imaging. The fabrication process of 2 mm rolled-copper sheath monofilament superconductor MgB2 wire using mechanical deformation process, including rolling and drawing, has been carried out. Starting by inserting powders, containing nominal composition of MgB2 into Cu tube with inner ø of 4 mm and outer ø of 6 mm, then they were rolled and drawn into wires (ø 2 mm), subsequently. The process of copper tube rolling was subsequently repeated in order to obtain three samples using added 5% CNT and 10% CNT to the pure MgB2, then were heat-treated at 800°C for 2 hours respectively. The writers evaluated the doping effect of two types multiwall carbon nanotube (MWCNT) with different aspect ratios on MgB2/Cu monofilament wires. Surface morphology was analyzed with SEM, crystal structure of MgB2 with XRD, whereas temperature dependence resistivity with four-point probe Cryogenic Magnet. SEM-EDS images showed that without addition of CNT, the crystal of MgB2 form dispersed uniformly in wire, but when added with 5% and 10% of CNT, the particle dispersed morphology was observed due to substitution of atom C into atom B. In contrast with pure MgB2, however, the pores increased as the CNTs doped increased of up to 5 wt%, makes it hard to identify the critical temperature. The temperature dependence of resistivity results showed that the critical temperatures were detected and kept shifting toward high 40 K with the addition of 10 wt% CNT. XRD analysis showed that some Mg may react with CNT to form MgB4 and graphite. Mg may react with oxygen to form MgO because the Cu sheath is not fully sealed and vacumed.

Integrasi Grafin Oksida Berbasis Larutan sebagai Material Penghantar Lubang pada Sel Surya Hibrid Bulk-Heterojunction (BHJ) Madsuha, Alfian F.; Sofyan, Nofrijon; Yuwono, A. H.
Prosiding Seminar Nasional Teknoka Vol 3 (2018): Prosiding Seminar Nasional Teknoka ke - 3
Publisher : Fakultas Teknik, Universitas Muhammadiyah Prof. Dr. Hamka, Jakarta

Dalam penelitian kali ini, telah didemonstarsikan penggunaan Grafin Oksida (GO) sebagai material pengantar lubang pada sel surya hibrid Bulk-Heterojunction (BHJ). Sebuah metode sederhana digunakan dalam memodifikasi anoda dari sel surya hibrid dengan cara mendeposisi material karbon nano hasil proses larutan diantara kaca transparan indium timah oksida(ITO) dan lapisan fotoaktif. Perngguanan GO ini ditujukan untuk mengganti secara keseluruhan polimer konduktif poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Dengan penggunaan lapisan GO ini, perbaikan efisiensi konversi energi dari 0,1% menjadi 1,66 % dapat dicapai melalu mekanisme penurunan hambatan seri (RS). Dengan hasil ini GO telah berhasil menunjukkan potensial yang besar untuk digunakan sebagai material pengantar lubang yang efisien pada sel surya hibrid

THE INFLUENCE OF MOLYBDENUM DISULPHIDE-FRICTION MODIFIER (FM) ADDITIVE INCREMENT ON THE FRICTION AND WEAR PREVENTION BEHAVIOUR OF HVI 60 BASE OIL Hanifuddin, Muhammad; Sofyan, Nofrijon
Scientific Contributions Oil and Gas Vol 38, No 2 (2015)
Publisher : PPPTMGB "LEMIGAS"

Friction will always be found in a mechanical system. It is therefore necessary to minimize friction, so itÂ becomes a more effi cient use of energy. This paper discusses the infl uence of MoS2 friction modifier (FM)Â additive in the form of powder with two different mesh sizes, i.e. 90 nm and 1.5 um, on the friction andÂ wear characteristic of HVI 60 base oil. The variation of MoS2 were 0,05%; 0,1%; 0,5% weight whereasÂ MoS2 1.5 um were 0,05%; 0,1%; 0,5%; 1% and 2% weight. MoS2 additive 90 nm was mixed with base oilÂ and stirred with magnetic stirrer for 60 minutes at 50oC and homogenized in an ultrasonic homogenizerÂ for 1 hour. For the MoS2 1.5 um, the additive was mixed with base oil and stirred with magnetic stirrer for 60 minutes at 75oC without using an ultrasonic homogenizer. Friction and wear characteristics of these mixtures were tested using four-ball and SRV test-rig. The wear scars were analyzed by using a scanning electron microscope (SEM). The results of the tests showed that the addition of 0.1% weight MoS2 additive, both in 90 nm and 1.5 um, resulted in an optimum increase in friction and wear characteristic of 23% and 11%, respectively. Observation on the wear scar showed that adhesive and abrasive wear mechanisms were involved in the wear process. The results of this research could be applied in the production of lubricating oils that can improve engine performance. Keywords: additive, friction, wear, molybdenum disulfi de, four-ball

Aplikasi Motif Batik Tradisional Surakarta Pada Produk Keramik Dinding Dengan Teknik Glasir Prima Yustana; Nofrijon Sofyan; Veronika Kristanti Putri Laksmi
Ornamen Vol 10, No 1 (2013)
Publisher : Institut Seni Indonesia Surakarta

This research was aimed at creating a new prototype ofdecorative wall ceramic characterized by local cultural character.The proposed work was motivated by the traditional batik characterizedby local style of Surakarta on the decorative wall ceramicby using glaze coloring techniques. An experimental study withseveral stages of material testing, firing, and glazing temperaturesas well as coloring motif with glaze techniques has beenperformed. The successful application of the traditional batik onthe ceramic wall with a glaze technique is expected to contributeprimarily to the creative industries. In addition, this decorativewall ceramic products would be able to support the opportunitiesto create new jobs based on the creative economy, in line withthe government program in addressing the unemployment. Theresulting prototype of decorative ceramic wall is also expected toprovide a solution to overcome local art and cultural identity degradationphenomena. Finally, in particular, the results of this studyare expected to (1) generate the description and identification ofthe problems arising in the process of decorative wall ceramicmaking by using glaze technique, (2) provide a new alternativeproducts, and (3) support the era of the creative industry with thecreation of new products that carry local cultural character andas a solution to the creation of a new field for the unemployment.Keyword: Wall Ceramic, Glazing Teqnique, Traditional Batik Surakarta

Integrasi Grafin Oksida Berbasis Larutan sebagai Material Penghantar Lubang pada Sel Surya Hibrid Bulk-Heterojunction (BHJ): Indonesian Alfian F. Madsuha; Nofrijon Sofyan; A. H. Yuwono
Prosiding Seminar Nasional Teknoka Vol 3 (2018): Prosiding Seminar Nasional Teknoka ke - 3
Publisher : Fakultas Teknik, Universitas Muhammadiyah Prof. Dr. Hamka, Jakarta

Dalam penelitian kali ini, telah didemonstarsikan penggunaan Grafin Oksida (GO) sebagai material pengantar lubang pada sel surya hibrid Bulk-Heterojunction (BHJ). Sebuah metode sederhana digunakan dalam memodifikasi anoda dari sel surya hibrid dengan cara mendeposisi material karbon nano hasil proses larutan diantara kaca transparan indium timah oksida(ITO) dan lapisan fotoaktif. Perngguanan GO ini ditujukan untuk mengganti secara keseluruhan polimer konduktif poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Dengan penggunaan lapisan GO ini, perbaikan efisiensi konversi energi dari 0,1% menjadi 1,66 % dapat dicapai melalu mekanisme penurunan hambatan seri (RS). Dengan hasil ini GO telah berhasil menunjukkan potensial yang besar untuk digunakan sebagai material pengantar lubang yang efisien pada sel surya hibrid

OBSERVASI LINGKUNGAN : KOMPOSISI DAN STRUKTUR MATERIAL BATUAN GUNUNG MERAPI DI D.I. YOGYAKARTA Imanudin Hidayat; Sunaryo Sunaryo; K.H. Firos Dawwas; Feti Eka Rahayu; Esty Asma Dewanti; Erfan Handoko; Fatah Nurdin; Nofrijon Sofyan; Bambang Soegijono
Jurnal Riset Sains dan Kimia Terapan Vol 3 No 2 (2013): JRSKT - Jurnal Riset Sains dan Kimia Terapan, Volume 3 Nomor 2 Desember 2013
Publisher : Program Studi Kimia Universitas Negeri Jakarta

Dengan tujuan mengetahui komposisi dan struktur yang terkandung dalam batuan pegunungan merapi di Daerah Istimewa Yogyakarta dilakukan observasi lingkungan. Ada tiga jenis batuan yaitu batuan merah, hitam, dan putih. Analisis struktur diketahui dengan difraksi sinar-X phillips radiasi Ka Co. Morfologi batuan diamati dengan scanning electron microscope (SEM). Komposisi batuan dengan menggunakan Energy Dispersive X-ray (EDX). Hasil karakterisasi menunjukkan bahwa semua batuan merupakan batuan kristal dengan komposisi fasa yang dominan untuk batuan merah yaitu SiO2, CaCO3, Al2O3, dan S. Sedangkan pada batuan hitam didominasi dengan kandungan SiO2 dan batuan putih dengan kandungan SiO2 dan S. Struktur mikro ketiga jenis batuan ini memiliki bentuk morfologi yang berbeda. Kata Kunci : Batuan pegunungan, batuan merah, hitam, putih, material kristal. In order to know structure and composition of contents in mountain rocks at Daerah Istimewa Yogyakarta, to be done enviorment observation. Three rocks are red, black, and white rocks. The analysis of crystal structures was examined by X-Ray Diffractometer (XRD) Phillips with Ka Co radiation. Morphology of three rocks was studied using a Scanning Electron Microscope (SEM). The composition of mountain rocks was detected by Energy Dispersive X-ray (EDX). The results shows that mountain rocks are crystal materials that phase composition of red rock are SiO2, CaCO3, Al2O3, and S. Black rock is SiO2 as mayor phase and white rock is consist of SiO2 and S. Microstructure of three rocks has the different morphology. Keywords : mountain rocks, red, black, white rocks, crystal materials.

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