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All Journal Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics Jurnal Sains Materi Indonesia IPTEK The Journal for Technology and Science JURNAL FISIKA Sainteknol : Jurnal Sains dan Teknologi Jurnal Spektra Jurnal Keramik dan Gelas Indonesia Omega: Jurnal Fisika dan Pendidikan Fisika Jurnal Teknologi Mineral dan Batubara INDONESIAN JOURNAL OF APPLIED PHYSICS Indonesian Mining Journal Indonesian Journal of Chemistry Jurnal Elektronika dan Telekomunikasi Jurnal Teknik Metalurgi Indonesian Physical Review Jurnal Riset Teknologi Industri Jurnal Keramik dan Gelas Indonesia Jurnal Ilmu Pengetahuan dan Teknologi (IPTEK) Makara Journal of Science Makara Journal of Technology Jurnal Teknologi Mineral dan Batubara Jurnal Sains Materi Indonesia Indonesian Mining Journal
Azwar Manaf
Departemen FMIPA, Universitas Indonesia
Agriculture, Biological Sciences & Forestry Astronomy Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Physics

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Synthesis of Single Phase BaFe12O19 Nanoparticle by Sol-Gel Method Dwita Suastiyanti; Bambang Soegijono; Azwar Manaf
JURNAL ILMU PENGETAHUAN DAN TEKNOLOGI (IPTEK) Vol. 9 No. 1 (2014): Jurnal Ilmu Pengetahuan dan Teknologi (IPTEK)
Publisher : Institut Teknologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31543/jii.v9i1.51

Abstract

Barium hexaferrite BaFe12O19 (BHF) is a great importance as permanent magnets, particularly formagnetic recording as well as in microwave devices. Barium hexaferrite also could be used as one of the basic constituent compound of multiferroic material. Multiferroic is a class of materials that yieldsimultaneous effects of ferroelectric,ferromagnetism and ferroelasticity in the same material. So BHF must be as nanoparticle and single phase to increase magnetoelectric coupling effect showing improvement multiferroic properties in material. Barium hexaferrite powders were prepared by sol gel auto combustion method. Hence the mole ratios of Ba2+/Fe3+ were varied at 1:12; 1:11.5 and 1:11 and sintering at 850oC for 10 hours for each mole ratios. To confirm the formation of single phase, it was used X-Ray Diffraction (XRD) Phillips, PW 1835 type in the 20o-100o diffraction angle using CuKα radiation. XRD results showed that sample with mole ratios of Ba2+/Fe3+ = 1:11,5 was best sample due to having single phase, 100% BHF phase be evidenced by HighScore Plus Refinement. Using Particle Size Analyzer (PSA) from Beckman Coulter type showed that sample with mole ratios of Ba2+/Fe3+ = 1:11,5 was powder in nano size, 66 nm (<100 nm). This research confirms that sol-gel method using mole ratio of Ba2+/Fe3+ = 1:11,5 and sinter temperature at 850oC for 10 hours could be used for synthesize single phase BHF in nanoparticle.
Microstructures, Magnetic Properties and Microwave Absorption Characteristics of Ti2+ -Mn4+Substituted Barium Hexaferrite Maykel Manawan; Azwar Manaf; Bambang Soegijono; Asep Yudi Hercuadi
Jurnal Elektronika dan Telekomunikasi Vol 14, No 1 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jet.v14.15-19

Abstract

The effect of Ti2+-Mn4+substitution on microwave absorption has been studied for BaFe12-2xTixMnxO19 ferrite, where x varies from 0.2, 0.4, 0.6 and 0.8.Ti2+-Mn4+ ions were obtained from TiO and MnO2 precursors which were mechanically alloyed together with BaCO3 and Fe2O3 precursors. X-ray diffraction (XRD) patterns for sintered samples confirmed that the materials are consisted with single phase BHF structure. Unit cell volume and crystallite size was found increase with increasing x. Crystallite size for all samples below 70 nm, but the grain morphology shown that the grains is in range of 200 - 400 nm, which concluded that each grain are polycrystalline. The saturation magnetization is increases up to x = 0.4 and decrease for higher x values, while the coercivity remains decreases monotonically. These results were interpreted in terms of the site preferential occupation of Ti2+ and Mn4+ at low level substitution.These substitution revealed of enhanced reflection loss (RL) up to 25 dB forx=0.6.It suggested that the synthesized can be employed as effective microwave absorbers in various devices.
Electromagnetic Wave Absorbing Materials on Radar Frequency Range Yana Taryana; Azwar Manaf; Nanang Sudrajat; Yuyu Wahyu
Jurnal Keramik dan Gelas Indonesia Vol 28, No 1 (2019): Jurnal Keramik dan Gelas Indonesia
Publisher : Balai Besar Keramik

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32537/jkgi.v28i1.5197

Abstract

Radar absorbing material (RAM) is a material that which can absorb and reduce energy of electromagnetic wave. Recently, RAMs are widely used as an isolator to protect electromagnetic wave interference (EMI) caused by external electromagnetic field and electromagnetic waves generated by radio frequency (RF) components that disturb the performance of a radio system. Whilest, the most strategic function is as anti-radar coating material to supply the needs of military systems such as aircraft, combat ships and other equipments. Generally, RAM must be resistive, magnetic and dielectric. Absorption at the resonant frequency region is indicated by the permitability and permeability values of the material. The Most literature has reported that the basic material which has the potential to absorb electromagnetic waves is ferrite-based magnetic material, namely barium hexaferrite and strontium hexaferrite. Therefore, the current development of research leads to modification and engineering of the material structure so that it is expected to obtain the right parameters with a maximum absorption rate. Generally, RAMs construction design are grouped on the impedance matching and resonant absorber types.
Studi Pelindian Mangan secara Reduksi dengan Menggunakan Larutan Asam Sulfat Ahmad Royani; Rudi Subagja; Azwar Manaf
Jurnal Riset Teknologi Industri Vol 11 No.1 JUNI 2017
Publisher : Balai Riset dan Standardisasi Industri Samarinda

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (427.533 KB) | DOI: 10.26578/jrti.v11i1.1724

Abstract

The leaching of manganese from manganese dioxide ores in sulfuric acid solution was investigated. The effects of agitation, sulfuric acid concentration and solid/liquid mass ratio on the leaching efficiency of manganese were studied. In this study, manganese dioxide ores were treated by reduction roasting using charcoal as a reductant at 700 oC for 120 min. Then, roasted samples were subjected to extract manganese by sulfuric acid leaching. in each leaching test, 75 g of sample was put and leached in a glass reactor with 750 mL sulfuric acid solution. At the end  of each leaching experiment, the slurry was filtered and filtrate was analyzed by Atomic Absorption Spectrometer. The experimental results indicated that the leaching rate increases with the increases of the agitation, sulfuric acid concentration and with the decreases of solid/liquid mass ratio. The optimal condition for leaching manganese from manganese dioxide ores was determined as the agitation of 400 rpm and sulfuric acid concentration of 12% for 180 min at 75 oC. Under the optimal condition, the leaching efficiency of manganese can reach 84.61%.  Keywords : leaching, manganese ore, manganese sulfate, sulfuric acidABSTRAKProses pelindian mangan dari bijih mangan dioksida dalam larutan asam sulfat telah berhasil dilakukan. Tujuan penelitian untuk mempelajari pengaruh dari kecepatan pengadukan, konsentrasi asam sulfat dan perbandingan massa padatan/larutan terhadap mangan yang terekstrak. Dalam penelitian ini, bijih mangan dipreparasi melalui proses reduksi menggunakan arang pada 700 oC selama 120 menit selanjutnya dilindi menggunakan larutan asam sulfat. Pada setiap percobaan, sebanyak 75 gram sampel dimasukkan dan dilindi dengan 750 ml larutan H2SO4dalam gelas reaktor. Setelah proses pelindian, kemudian disaring dan dianalisa dengan menggunakan Atomic Absorption Spectrometer. Hasil percobaan menunjukkan bahwa laju pelindian meningkat dengan naiknya kecepatan pengadukan dan konsentrasi asam serta menurunnya rasio perbandingan persen padatan. Kondisi optimum diperoleh pada kecepatan pengadukan 400 rpm, konsentrasi asam sulfat 12% pada 75 oC selama 180 menit dengan mangan terekstrak sebesar 84,61%.Kata kunci : asam sulfat, bijih mangan, pelindian, mangan sulfat
SINTESIS PIGMEN BESI OKSIDA BERBAHAN BAKU LIMBAH INDUSTRI BAJA (MILL SCALE) Tito Prastyo Rahman; Agus Sukarto; Nurul Taufiqu Rochman; Azwar Manaf
Jurnal Fisika Vol 3, No 1 (2013)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v3i1.3972

Abstract

Limbah industri baja (mill scale) digunakan sebagai alternatif bahan baku pigmen besi oksida. Kajian ilmiah ini menjelaskan proses pembuatan pigmen besi oksida melalui metode presipitasi dengan media air. Pigmen besi oksida yang menjadi target yaitu pigmen kuning goethit ( -FeOOH) dan merah hematit ( -Fe2O3). Goethit diperoleh dengan presipitasi menggunakan amonia dari proses awal terbentuknya ferricssulfat hasil reaksi asam sulfat (H2SO4) dengan limbah mill scale, sedangkan hematit diperoleh dengan proses pemanasan goethit pada temperatur 5000C dan 9000C. Analisa XRD digunakan untuk mengetahui senyawa pigmen yang terkandung dan penggunaan DTA untuk mengetahui pola perubahan fasa akibat proses pemanasan fasa goethit. Analisa warna pigmen menggunakan collorimetri L*a*b System. Warna pigmen yang diperoleh mempunyai tinting strength yang masih kurang dibandingkan dengan pigmen impor.
Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water Saksono, Nelson; Bismo, Setijo; Krisanti, Elsa; Manaf, Azwar; Widaningrum, Roekmijati
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

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Abstract

Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water. Magnetic treatment is applied as physical water treatment for scale prevention especially CaCO3, from hard water in piping equipment by reducing its hardness. Na2CO3 and CaCl2 solution sample was used in to investigate the magnetic fields influence on the formation of particle of CaCO3. By changing the strength of magnetic fields, exposure time and concentration of samples solution, this study presents quantitative results of total scale deposit, total precipitated CaCO3 and morphology of the deposit. This research was run by comparing magnetically and non-magnetically treated samples. The results showed an increase of deposits formation rate and total number of precipitated CaCO3 of magnetically treated samples. The increase of concentration solution sample will also raised the deposit under magnetic field. Microscope images showed a greater number but smaller size of CaCO3 deposits form in magnetically treated samples, and aggregation during the processes. X-ray diffraction (XRD) analysis showed that magnetically samples were dominated by calcite. But, there was a significant decrease of calcite’s peak intensities from magnetized samples that indicated the decrease of the amount of calcite and an increase of total amorphous of deposits. This result showed that magnetization of hard water leaded to the decreasing of ion Ca2+ due to the increasing of total CaCO3 precipitation process.
Effects of Ph on Calcium Carbonate Precipitation Under Magnetic Field Saksono, Nelson; Yuliusman, Yuliusman; Bismo, Setijo; Soemantojo, Roekmijati W.; Manaf, Azwar
Makara Journal of Technology Vol. 13, No. 2
Publisher : UI Scholars Hub

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Abstract

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In high super-saturated solution, magnetic field strengthens ion interactions, which reduce precipitation during circulation process. However, in low super-saturated CaCO3 solution, magnetic field weakens hydrate ion interaction which indicated by decreasing of the conductivity of solution. It increases the precipitation of CaCO3 after the circulation of magnetization process has completed.
Formation of CaCO3 Particle and Conductivity of Na2CO3 and CaCl2 Solution Under Magnetic Field on Dynamic Fluid System Saksono, Nelson; Bismo, Setijo; Widaningroem, Roekmijati; Manaf, Azwar
Makara Journal of Technology Vol. 15, No. 1
Publisher : UI Scholars Hub

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Abstract

Hard water causes the CaCO3 scale formation on the pipe walls and heat exchanger equipments in industrial or domestic water processes. A great number of experimental researches on the prevention of the CaCO3 precipitation process by magnetic field have been carried out. In this research, Na2CO3 and CaCl2 solutions was magnetized in the circulated flow condition (dynamic fluid system). The velocity of fluid and the circulation time was modified to examine its influences to the magnetization process. CaCO3 content was measured by titration method of EDTA complexometry. Conductivity test was conducted to find out hydrate ion bonding. The results showed that magnetization increased the CaCO3 formation and the optimum process reaches for 10 minutes circulation on 0.554 m/s of flow rate. Magnetic field decreases the conductivities of Na2CO3 and CaCl2 solution, hence reduced the ion hydrate bonding. These results showed that magnetization on Na2CO3 and CaCl2 ionic solution was effective in controlling the CaCO3 formation by increasing CaCO3 precipitation.
Correlation between Scattering Matrix, Return Loss and Interface Reflection Loss in Nicolson Rose Wear Approximation Wakid Ali Muntoha; Adam Badra Cahaya; Azwar Manaf
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.5, N
Publisher : Physics Study Programme, Faculty of Science and Technology UIN Syarif Hidayatullah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v5i2.22353

Abstract

The phenomenon behind the absorption of electromagnetic waves by absorbingmaterials is resonance phenomenon. When there is a similarity between the value of theimpedance of electromagnetic waves in the air and the impedance of the material, theabsorption of energy by the material is maximized. The phenomenon is measured using anauxiliary instrument, namely the Vector Network Analyzer. This instrument is very effective forcalculating the absorption value of electromagnetic waves. However, the Vector NetworkAnalyzer instrument which is mostly available in Indonesian research institutions cannot directlydisplay the reflection loss of the electromagnetic wave absorbing material. An effective methodthat is effective for calculating the absorption in electromagnetic wave absorbing material isNicolson Rose Wear method. In this article, we design a computational tool based on NicolsonRose Wear approximation to calculate the reflection loss values from scattering matrix andcomparing it with return loss, which is often mistook as reflection loss.
Correlation between Scattering Matrix, Return Loss and Interface Reflection Loss in Nicolson Rose Wear Approximation Wakid Ali Muntoha; Adam Badra Cahaya; Azwar Manaf
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.5, N
Publisher : Physics Study Programme, Faculty of Science and Technology UIN Syarif Hidayatullah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v5i2.22353

Abstract

The phenomenon behind the absorption of electromagnetic waves by absorbingmaterials is resonance phenomenon. When there is a similarity between the value of theimpedance of electromagnetic waves in the air and the impedance of the material, theabsorption of energy by the material is maximized. The phenomenon is measured using anauxiliary instrument, namely the Vector Network Analyzer. This instrument is very effective forcalculating the absorption value of electromagnetic waves. However, the Vector NetworkAnalyzer instrument which is mostly available in Indonesian research institutions cannot directlydisplay the reflection loss of the electromagnetic wave absorbing material. An effective methodthat is effective for calculating the absorption in electromagnetic wave absorbing material isNicolson Rose Wear method. In this article, we design a computational tool based on NicolsonRose Wear approximation to calculate the reflection loss values from scattering matrix andcomparing it with return loss, which is often mistook as reflection loss.
Co-Authors Adi Ganda Putra Agus Sukarto Agus Sukarto Ahmad Royani Akmal Johan Andreas Andreas Arie Fiandimas Arieko Abdillah Asep Yudi Hercuadi Asep Yudi Hercuadi, Asep Yudi Bahfie, Fathan Bambang Soegijono Birawidha, David C Budhy Kurniawan Cahaya, Adam Badra Daulay, Amru Dedi Dedi Diah Susanti Djoko HP Doansi Tarihoran Dwita Suastiyanti Eddy Siradj Edie Sasito, Edie Eko Sulistiyono, Eko Elda Rayhana Elfrida Ratnawati Elisabeth A. S. Elsa Krisanti Erfan Handoko Erik Prasetyo Fajar Nurjaman Fajar Nurjaman Fathan Bahfie firdiyono, F Handoko, Djati Hasan Fahad Idris Novianto Iskandar Muda Iskandar Muda Iskandar Muda Lingga Hermanto Mabe Siahaan Manawan, Maykel Manawan, Maykel Mas Ayu Elita Hafizah Maykel Manawan Mujamilah Mujamilah Mulyaningsih, Neng Nenden Musfirah Cahya Fajrah, Musfirah Cahya Nanang Sudrajat Nelson Saksono Nelson Saksono Novizal Novizal, Novizal Novrita Idayanti Nurul Taufiqu Rochman Nurul Taufiqu Rochman Pontas Sialagan Priyono K. Priyono P Priyono Priyono Rafael F Maniur Ridwan Ridwan Roekmijati Soemantojo Roekmijati Soemantojo, Roekmijati Roekmijati W. Roekmijati W. Soemantojo, Roekmijati W. Roekmijati Widaningroem Roekmijati Widaningroem, Roekmijati Roekmijati Widaningrum Roekmijati Widaningrum, Roekmijati Rudi Subagja Saptari, Sitti Ahmiatri Setijo Bismo Setijo Bismo Setyo Purwanto Setyo Purwanto Sialagan, Pontas Sipahutar, Wahyu Solafide Sri Mulyaningsih Sri Mulyaningsih Suprihatin Suprihatin Taufik A. Bonaedy Tito Prastyo Rahman Tito Prastyo Rahman, Tito Prastyo Tri Haryono Ulin Herlina Valency, Tiara Wakid Ali Muntoha Widi Astuti Widi Astuti Wisnu A. Adi Wisnu Ari Adi Wisnu Ari Adi Wisnu Ari Adi Yana Taryana Yuliana Sari Yuliusman Yuliusman Yuliusman Yuliusman Yuyu Wahyu