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All Journal Jurnal Ilmu Dasar BERKALA SAINSTEK JURNAL FISIKA ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika Jurnal Penelitian Pendidikan IPA (JPPIPA) INDONESIAN JOURNAL OF APPLIED PHYSICS Jurnal Pendidikan Fisika dan Keilmuan (JPFK) Jurnal Ilmu Fisika Majalah Ilmiah Matematika dan Statistika (MIMS) Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Journal of Energy, Material, and Instrumentation Technology PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) Newton-Maxwell Journal of Physics TEFLICS InSTEM
Lutfi Rohman
Jurusan Fisika, Fakultas Matematika Dan Ilmu Pengetahuan Alam, Universitas Jember (UNEJ)
Agriculture, Biological Sciences & Forestry Arts Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Other

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Kurva histeresis bahan feromagnetik Co0.8Pt0.2 pada tiga daerah domain Hasanah, Irmawati; Rohman, Lutfi; Supripyanto, Edy
Jurnal Pendidikan Fisika dan Keilmuan (JPFK) Vol 6, No 1 (2020)
Publisher : UNIVERISTAS PGRI MADIUN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25273/jpfk.v6i1.5236

Abstract

Bahan magnetik alloy  Co0.8Pt0.2, merupakan bahan yang mempunyai konstanta anisotropi dan tahanan korosi yang tinggi sehingga bisa dijadikan pembuatan hardisk dengan kapasitas penyimpanan yang besar pada ukuran nanometer. Ukuran kritis bahan CoPt dianalisis dengan grafik hubungan rapat energi dengan ukuran sisi kubus yang terdapat tiga zona domain, yakni single domain, transisi dan multi domain. Nilai ukuran kritis yang dihasilkan sebesar 20 nm, nilai tersebut dilihat dari titik akhir dari zona single domain yang akan menuju ke zona transisi. Kurva histerisis bahan CoPt ini menghasilkan medan koersivitas yang kecil yaitu seperti halnya magnet dalam golongan soft magnet. Penelitian ini mengkaji sifat magnetik bahan CoPt dalam bentuk nanocube menggunakan kurva histerisis dan ukuran kritis yang dikaji dalam bentuk grafik hubungan rapat energi (KJ/m3) dengan ukuran sisi kubus (nm) yang dilakukan dengan memvariasikan ukuran bahan. Ukuran kritis dapat ditinjau dengan membaginya dalam tiga zona yakni single domain, transisi dan multi domain. Nilai ukuran kritis bahan sebesar 20 nm. Kurva histerisis pada zona single domain dengan sisi kubus 8 nm medan koersivitas bernilai 3,46×10-7 T, pada zona transisi 20 nm medan koersivitas yang dihasilkan sebesar 9,43×10-7 T sedangkan pada multi domain 29 nm medan koersivitas yang dihasilkan bernilai 1,5×10-6 T.Kata Kunci: CoPt, Ukuran Kritis, Kurva histerisis, nanocube, magnetisasi saturasi.
Scaling Properties in the Non-Linear Diffusion Equation and Its Application to the Problem of Water Transport in Water Unsaturated Soils Rohman, Lutfi
Majalah Ilmiah Matematika dan Statistika Vol 16 No 2 (2016): Majalah Ilmiah Matematika dan Statistika
Publisher : Jurusan Matematika FMIPA Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/mims.v16i2.23744

Abstract

In this work, we investigate the scaling properties related to the nonlinear fractional diffusion equations and indicate the possibilities to the applications of these equations to simulate the water transport in unsaturated soils. Usually, the water transport in soils with anomalous diffusion, the dependence of concentration on time (t) q and distance (x) may be expressed in term of a single variable given by λq = x / tq . In particular, for q = 1/2 the systems obey Fick’s law and Richards’ equation for water transport. We show that a generalization of Richards’ equation via fractional approach can incorporate the above property.
Simulation of Formation of Icosahedral Structure in Solid-Liquid-Solid Phase Change Using Molecular Dynamics Methods Nikodemus Umbu Janga Hauwali; Artoto Arkundato; Lutfi Rohman
Jurnal ILMU DASAR Vol 17 No 1 (2016)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (279.395 KB) | DOI: 10.19184/jid.v17i1.2661

Abstract

It has successfully conducted research to study the structure of the icosahedral formation in the event of change of the solid phase - liquid-solid using molecular dynamics method . The result showed that the percentage of the maximum icosahedral structure is obtained when the simulation is run at the start of the cooling temperature of 2875 K at a rate of temperature decrease of 0.064 K /step and at the beginning of the cooling temperature of 3000 K at a rate of temperature decrease 0.12 K/step. While icosahedral minimum percentage obtained when the simulation is run at a temperature of 2750 K with the initial cooling rate of temperature decrease of 0.069 K/step. Based on these results we can conclude that there is a relationship between the initial temperature of the cooling and the rate of temperature decrease of the icosahedral structure is formed. Keywords: Icosahedral, phase change, molecular dynamics
Temperatur Curie dan Medan Koersivitas Material Co0,8Ni0,2 dalam Struktur Random Alloy dan Double Layers Lutfi Rohman; Suci Novitasari; Supriyadi Supriyadi
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 10, No 01 (2020): April
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (598.215 KB) | DOI: 10.13057/ijap.v10i01.31346

Abstract

Material Kobalt Nikel (CoNi) merupakan paduan penting karena memiliki sifat kemagnetan yang baik diantaranya yaitu temperatur curie dan koersivitas yang tinggi. komposisi, struktur alloy dan ukuran sisi kubus bahan berpengaruh terhadap temperatur Curie dan koersivitas. Simulasi mikromagnetik dilakukan pada material Co0,8Ni0,2 dengan struktur random alloy dan double layers untuk menentukan nilai temperatur Curie dan analisis kurva histerisis. Simulasi material Co0,8Ni0,2 dilakukan menggunakan software Vampire dengan variasi ukuran sisi kubus yang digunakan yaitu 5 nm, 8 nm, 10 nm, 12 nm, dan 15 nm. Hasil simulasi menunjukkan nilai temperatur Curie semakin meningkat dengan bertambahnya ukuran sisi kubus. Pada material Co0,8Ni0,2 double layers diperoleh nilai temperatur Curie lebih tinggi dari pada material Co0,8Ni0,2 random alloy. Karakteristik kurva histerisis pada material Co0,8Ni0,2 random alloy dan double layers menunjukkan bahwa nilai koersivitas meningkat seiring bertambahnya ukuran sisi kubus. Namun pada material Co0,8Ni0,2 random alloy ketika ukuran bahan yang diberikan 12 nm dan 15 nm nilai medan koersivitasnya semakin menurun, dibandingkan saat ukuran 10 nm. Pada ukuran sisi kubus 10 nm dikatakan sebagai ukuran terbaik dari material Co0,8Ni0,2 random alloy ditinjau dari nilai medan koersivitas yang besar.
Analisis Hasil Perkuliahan E-Learning Elektronika Menggunakan Model Statistik Analisis Ragam DuaAarah (Two Way Analysis of Variance) Di Jurusan Fisika, Universitas Negeri Jakarta Yuliana Yuliana; Fitri Ayu Sundari; Agus Setyo Budi; Hadi Nasbey; I. Made Astra; Sifa Alfiyah; Iwan Sugihartono; Cuk Imawan; Lutfi Rohman
PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) Vol 2 (2013): PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) SNF2013
Publisher : Program Studi Pendidikan Fisika dan Program Studi Fisika Universitas Negeri Jakarta, LPPM Universitas Negeri Jakarta, HFI Jakarta, HFI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (270.602 KB)

Abstract

Analisis hasil perkuliahan e-learning elektronika menggunakan model statistik analisa ragam dua arah (Two Ways Analysis of Variance) di jurusan fisika, Universitas Negeri Jakarta telah dilakukan. Penelitian ini dilakukan dengan mengunakan model statistik ragam dua arah (Two Ways Analysis of Variance) dari hasil belajar elektronika seperti tugas baca, latihan, dan kuis dengan masing-masing tugas baca, latihan, dan kuis terdiri dari tugas baca 1, tugas baca 2, tugas baca 3, latihan 1, latihan 2, latihan 3, kuis 1, kuis 2, dan kuis 3. Adapun analisa model statistik yang dilakukan dengan mengolah data hasil belajar elektronika kedalam bentuk statistik dan melakukan analisa ragam dua arah (Two Ways Analysis of Variance). Pengolahan data ke dalam bentuk statistik memperlihatkan kurva dan grafik pola histogram dari hasil analisa frekuensi hasil belajar elektronika, sedangkan analisa menggunakan uji analisa ragam dua arah (Two Ways Analysis of Variance) dapat diketahui bahwa mahasiswa jurusan Fisika 2011, Universitas Negeri Jakarta memilki kemampuan yang berbeda dan juga untuk tugas baca, latihan, dan kuis mempunyai tingkat kesulitan yang berbeda. Pada tugas baca memilki kesulitan yang lebih rendah dibandingkan latihan dan kuis, analisa ragam dua arah (Two Ways Analysis of Variance) memperlihatkan bahwa nilai latihan dan kuis mahasiswa lebih rendah dibandingkan nilai tugas baca mahasiswa. kata kunci : two ways Analysis of Variance, elektronika, e-learning.
Rigid Procedure to Calculate the Melting Point of Metal Using the Solid-Liquid Phase (Coexistence) Method Artoto Arkundato; Wenny Maulina; Lutfi Rohman; Ratna Dewi Syarifah; Mohammad Ali Shafii
Jurnal Ilmu Fisika Vol 14 No 2 (2022): September 2022
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.14.2.132-140.2022

Abstract

Melting point, particularly metal, is one of the important data for many applications. For developing new materials, adequate theories for melting point are very crucial. The determination of melting point using the popular phase-change curve method is very easy but usually overestimate. In current work, we determine the melting point of a pure metal (iron) using the method of solid-liquid phase coexistence. For this goal, molecular dynamics simulation was applied to obtain data of trajectories of atoms. Simulation (LAMMPS) and data analysis (OVITO) procedures are strictly applied to obtain the accurate melting point of iron based on the obtained trajectories data. For initial structure design of simulation, we used the ATOMSK program. The melting point of iron obtained using the phase change curve (PCC) method is about 2750 K < TPCC < 3250 K and using the coexistence phase (CP) method is TCP = 2325 K. A more accurate calculation needs to include defects factor in the simulated material and calculation. In this research we use the Morse potential to represent all of the atomic interaction among atoms of Fe material.
Analisis Perbandingan Desain Geometri Pin Bahan Bakar Heksagonal dan Persegi GFR Menggunakan Bahan Bakar Uranium Karbida Maulana, Muhammad Rizqi; Syarifah, Ratna Dewi; Prasetya, Fajri; Mabruri, Ahmad Muzaki; Arkundato, Artoto; Rohman, Lutfi
Journal of Energy, Material, and Instrumentation Technology Vol 5 No 3 (2024): Journal of Energy, Material, and Instrumentation Technology
Publisher : Departement of Physics, Faculty of Mathematics and Natural Sciences, University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jemit.v5i3.252

Abstract

Comparative Analysis of Hexagonal and Square GFR Fuel Pin Geometry Designs with Uranium Carbide Fuel has been carried out. Nuclear reactors from Generation I to IV have developed significantly, with Gas-cooled Fast Reactors (GFR) being a potential candidate for operation by 2030. This study focuses on a GFR reactor utilizing uranium carbide (UC) fuel with a low input power of 300 MWth. The reactor core adopts a cylindrical pancake geometry with 100 cm height and 240 cm diameter dimensions. The objective is to compare the optimal design between hexagonal and square pin cell geometries for GFR-type fast reactors. The study employs the SRAC 2006 software with the JENDL 4.0 database. The research involves homogenous core configuration calculations, heterogeneous core configuration calculations, and variations in fuel fraction to determine optimal data for hexagonal and square pin cell configurations. Results indicate that heterogeneous fuel configurations require fuel fractions of 51% for hexagonal pins and 59% for square pins, with comparable maximum power performance at End of Life (EOL) and Beginning of Life (BOL). It suggests that hexagonal pins are more efficient, requiring less fuel material to maintain reactor criticality over a 20-period burn-up.
Preliminary Study of The Structure of Hesperidin and Neohesperidin as a Potential Inhibitor of SARS-CoV-2 by using The DFT Method Sulisti, Wahyu; Sahiroh, Samakhatus; Rohman, Lutfi; Arkundato, Artoto; Wibawa, Wibawa
Jurnal Fisika Vol 13, No 2 (2023)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v13i2.47640

Abstract

The discovery of drugs as COVID-19 antivirals has been intensively carried out by researchers as an effort to reduce the number of victims of the COVID-19 pandemic in 2020. The discovery of main protease (Mpro) which plays a role in protein replication and transcription helped researchers identify virus inhibitors. This research has examined the potency of the bioflavonoid compounds hesperidin and the flavanon glycosides neohesperidin and their structural stability as potential inhibitors of SARS-CoV-2 by DFT computation. The first method used is the calculation of density functional theory (DFT) on hesperidin and neohesperidin molecules to optimize the geometry of the molecular structure, analysis of frontier molecular orbitals (FMO), chemical reactivity index, and map electrostatic potential (MEP).
Study of Vortex Generator Effect on Airfoil Aerodynamics Using the Computational Fluids Dynamics Method Ayudia, Siti Aisyah; Arkundato, Artoto; Rohman, Lutfi
Computational And Experimental Research In Materials And Renewable Energy Vol 3 No 2 (2020): November
Publisher : Physics Department, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/cerimre.v3i2.23547

Abstract

The lift force is one of the important factors in supporting the aircraft flying capabilities. The airplane has a section called the aircraft wing. In particular, the wing section of aircraft is called the airfoil. One of the efforts to increase the lift force is to make the flow of air fluid at the top of the airfoil more turbulent. Turbulent flow can attract momentum from the boundary layer, the result of this momentum transfer has energy that is more resistant to the adverse pressure gradient which can trigger the flow separation. Efforts that can be made to reduce separation flow and increase lift force are the addition of a turbulent generator on the upper surface of the airfoil, one type of turbulent generator is a vortex generator, a vortex generator can accelerate the transition from the laminar boundary layer to the turbulent boundary layer. This study was conducted with the aim of knowing the effect of the vortex generator on the aerodynamics of NACA-4412 using the computational fluid dynamics method. The main thing that will be investigated is the effect of the straight type vortex generator application on the lift coefficient, by comparing the plain airfoil and airfoil that has been applied to the vortex generator to vary the angle of attack. The variation of the angles of attack are 0º, 5º, 10º, 15º and the placement of the vortex generator is 24% of the leading edge. The results obtained that the lift coefficient changes with increasing angle of attack and the application of a vortex generator to an airfoil can increase the lift coefficient than a plain airfoil. The optimum increase in lift coefficient is at the angle of attack of 5º as much as 13%.
Analysis Curie Temperature and Hysteresis La0,7Sr0,3MnO3 with Micromagnetic Simulation Febiantoro, Muhamad Rony; Rohman, Lutfi; Sutisna, Sutisna
Computational And Experimental Research In Materials And Renewable Energy Vol 3 No 2 (2020): November
Publisher : Physics Department, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/cerimre.v3i2.23545

Abstract

Simulation reseach has been carried out to obtain the characteristic of material La0,7Sr0,3MnO3. The simulation method used atomistic of magnetic materials. Simulations were carried out using Vampire software Micromagnetic simulation were determine Curie temperature and Hysterisis Curve. The monte carlo algorithm was used in this reseach. Simulation were carried out by variation nanocube size 22 nm, 27 nm, and 32 nm. The simulation result show, Curie temperature show in 27 nm have the biggest value and stuck in that value. The characteristics of the Hysterisis curve 32 nm bigger than the others.From the simulation, it is found that the between the temperature and Hysteris curve. More temperature value, the smaller the Hysterisis curve.
Co-Authors Agus Setyo Budi Al Islam, Hanif Mufti Arofah, Siti Lailatul Artoto Arkundato Ayudia, Siti Aisyah Cahyono, Bowo Eko Cuk Imawan Dita Puspita, Dita Edy Supriyanto Endhah Purwandari Fachry Abda El Rahman Febiantoro, Muhamad Rony Firdaus, Rohim Aminullah Fitri Ayu Sundari Hadi Nasbey Hasanah, Irmawati Hidayah, Elok Hidayat, Umar Sahiful I Made Astra Imam Wahyudi Indrawan, Imam Wahyudi Irvan Siswanto Iwan Sugihartono Karomah, Iklimatul Mabruri, Ahmad Muzaki Maulana, Muhammad Rizqi Mohammad Ali Shafii Musyarofah, L. Mutmainnah Mutmainnah Nikodemus Umbu Janga Hauwali Ni’mah, Khiptiatun NUR OCTAVINA, CHOIRINA RACHMA Prasetya, Fajri Sahiroh, Samakhatus Sa’adah, Umi Sifa Alfiyah Suci Novitasari Sulisti, Wahyu Supripyanto, Edy Supriyadi Supriyadi Sutisna Sutisna Syarifah, Ratna Dewi Trianti, Nuri Wenny Maulina, Wenny Wibawa Wibawa, Wibawa Wicaksono, Angga Widiasih Yuliana Yuliana