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Determination of Sesame Oil Quality UsingFraunhofer Difraction Method: Refraction Index as a Temperature Function Nur Inna Alfianinda; Misto Misto; Artoto Arkundato
Jurnal ILMU DASAR Vol 15 No 1 (2014)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (918.971 KB) | DOI: 10.19184/jid.v15i1.834

Abstract

Telah dirancang alat uji kemurnian bahan yang bekerja berdasarkan metode difraksi Fraunhofer celah ganda. Metode ini mempunyai akurasi yang baik, tidak memerlukan bahan uji dalam jumlah banyak serta tidak merusak kemurnian bahan uji itu sendiri (non destructive testing/non contactive testing). Pengujian dilakukan dengan menentukan persamaan indeks bias sebagai fungsi suhu bahan uji, yang diperoleh berdasarkan perubahan pola frinji gelap terang difraksi cahaya yang melewati bahan uji untuk variasi suhu yang diberikan (26 °C hingga 90 °C). Dari persamaan indeks bias yang diperoleh kemudian dapat dihitung indeks bias pada suhu sembarang. Uji kemurnian dilakukang dengan membandingkan nilai indeks bias terukur dengan nilai indeks bias referensi pada suhu tertentu. Uji statistik t-test digunakan untuk melihat tingkat akurasi alat. Pada penelitian ini digunakan tiga buah merk minyak wijen yang ada di pasaran. Dari hasil pengukuran dan perhitungan menggunakan minyak wijen tiga macam (A,B dan C) dapat diketahui bahwa dari ketiga bahan uji yang dipilih maka minyak wijen label B memiliki nilai t hitung yang paling kecil dibandingkan minyak wijen label A dan C, sehingga minyak wijen label B dianggap memiliki kualitas yang paling baik dia antara ketiga minyak wijen yang telah di uji. Keywords: Difraksi Fraunhofer, minyak wijen, indeks bias bahan, uji-t  
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
HEATING AND QUENCHING PROCEDURE ON THE MAKING OF TRADITIONAL BLACKSMITH STEEL WITH HIGH QUALITY Artoto Arkundato; Misto Misto; Hadi Paramu; Gaguk Jatisukamto; Iwan Sugihartono
Spektra: Jurnal Fisika dan Aplikasinya Vol 4 No 1 (2019): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 4 Issue 1, April 2019
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (358.01 KB) | DOI: 10.21009/SPEKTRA.041.05

Abstract

Blacksmith is a people's business that has been going on for a long time in Indonesia. Based on the experience that has been obtained from time to time and hereditary, the blacksmith industry has been done by the community to meet the needs of agricultural and household utensils. However, observe to this people's business, now it decreases with various causal factors, such as the ease of imported goods on the market with lower prices. Many creative efforts need to be carried out so that these people's businesses remain and increasingly develop, among others by improving the quality of the process of a blacksmith so that their products are quite competitive. This article describes the results of the research in the laboratory regarding the physical processes of heating and quenching under blacksmith, which the results have been applied to community service activities at the Suger Kidul villages in Jember Regency. The study aimed to find the most appropriate procedure for steel tool manufacturing processes so that the blacksmith products have high quality as high hardness. The physical process for blacksmith process is heating and quenching. This study analyzes the proper heat (temperature), proper processing time, and proper media for heating and quenching to produce good harness quality of the product.
Structural and Photoluminescence Properties of ZnO Thin Films Deposited by Ultrasonic Spray Pyrolysis Sugihartono, Iwan; Handoko, Erfan; Fauzia, Vivi; Arkundato, Artoto; Sari, Lara Permata
Makara Journal of Technology Vol. 22, No. 1
Publisher : UI Scholars Hub

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

Abstract

Zinc oxide (ZnO) thin films on a silicon (Si) (111) substrate were grown herein using ultrasonic spray pyrolysis at 450 °C with different Zn concentrations. The ZnO thin films had X-ray diffraction patterns of a polycrystalline hexagonal wurtzite structure. The (002) and (101) peak intensities changed under different Zn concentrations. Furthermore, according to Scherer's and Stokes–Wilson equations, the crystallite size and the internal strain of the ZnO thin films in the (002) and (101) peaks changed with the Zn concentration. Optically, the photoluminescence spectra indicated that the ratio of the UV/GB emission of the ZnO thin films was the highest at the Zn concentration of 0.02 mol/mL. We predicted that by increasing the Zn concentrations, the nonradiative transitions, which originated from defects, such as lattice and surface defect, become dominant. In conclusion, the ZnO thin films with the Zn concentration of 0.02 mol/mL had a better crystalline and optical quality.
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.
PENGARUH MICROWAVE ASSISTED PADA KURVA HISTERISIS MULTI DOMAIN BAHAN FEROMAGNETIK NIFE Edy Wahono; Luthfi Rohman; Artoto Arkundato
saintifika Vol 22 No 1 (2020)
Publisher : FKIP Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (164.967 KB)

Abstract

Bahan alloy NiFe merupakan salah satu bahan feromagnetik yang memilki tekstur kuat dengan nilai anisotropi magnetik dan medan koersivitas besar. Kurva histerisis bahan NiFe ini menghasilkan medan koersivitas yang besar dalam golongan hard magnet. Penelitian ini mengkaji pengaruh dari microwave assisted pada kurva histerisis bahan NiFe dalam bentuk ellipsoid. Pengaruh microwave assisted membantu untuk mengecilkan medan koersivitas sehingga mengalami pembalikan magnetisasi semakin cepat untuk kembali pada posisi awal. Hasil simulasi pada ukuran 50 nm struktur multi domain dengan memberikan frekuensi 20 GHz dan amplitudo 100 mT diperoleh medan koersivitas sebesar 80 mT sedangkan pada frekuensi 200 GHz dan amplitudo 1000 mT diperoleh medan koersivitas sebesar 55 mT. Pengaruh dari microwave assisted yang dipengaruhi terjadi perubahan medan koersivitas yang semakin kecil.
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

Analisis Perbandingan Desain Geometri Pin Bahan Bakar Heksagonal dan Persegi GFR dengan Bahan Bakar Uranium Karbida telah dilakukan.Reaktor nuklir dari generasi I hingga IV mengalami perkembangan yang cukup signifikan. Salah satu reaktor generasi IV yang berpotensi dapat beroperasi di tahun 2030 adalah reaktor cepat jenis Gas-cooled Fast Reactor (GFR). Penelitian ini menggunakan reaktor GFR dengan bahan bakar uranium karbida (UC) dan daya input rendah sebesar 300MWth. Teras reaktor menggunakan desain geometri cylinder pancake dengan tinggi 100 cm dan diameter 240 cm. Penelitian ini bertujuan untuk membandingkan desain optimal variasi sel pin geometri heksagonal dan persegi untuk reaktor cepat tipe GFR. Penelitian dilakukan dengan menggunakan software SRAC 2006 dengan database JENDL 4.0. Tahapan yang dilakukan dalam penelitian ini adalah melakukan perhitungan konfigurasi inti homogen, perhitungan konfigurasi inti heterogen, kemudian melakukan variasi fraksi bahan bakar untuk menghasilkan data yang optimal pada variasi sel pin heksagonal dan sel pin persegi. Hasil menunjukkan bahwa desain optimal diperoleleh pada desain heterogen dengan persentase pengayaan uranium untuk F1, F2, dan F3 sebesar 11.5% - 12% - 12.5%. Desain optimal dengan persentase tersebut dicapai pada fraksi fuel 51% untuk geometri pin heksagonal dan 59% untuk geometri persegi.
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).
The Effect of Adding Minor Actinide Fuel Rods on GFR Reactor in Radiopharmaceutical Waste Production Using OpenMC Program Syarifah, Ratna Dewi; Prasetya, Fajri; Mabruri, Ahmad Muzaki; Arkundato, Artoto; Trianti, Nuri
Science and Technology Indonesia Vol. 9 No. 4 (2024): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2024.9.4.857-865

Abstract

GFR is a generation IV reactor based on helium gas refrigeration capable of working at very high temperatures. The fast spectrum in this reactor makes it possible to use nitride-based fuel, namely Uranium Plutonium Nitride (UN-PuN). Adding minor actinide (MA) material to the primary fuel, UN-PuN can maximize reactor performance to near critical from the beginning to the end of burn-up. This study aims to analyze the effect of adding MA fuel rods to the heterogeneous core of 5 fuel variations (F1, F2, F3, F4, F5) on the probability of radiopharmaceutical waste production. The method in this research is to place MA fuel rods in this study using four designs based on the highest neutron flux value in one fuel assembly. The results of the neutron flux calculation show that the reactor’s active core’s central region (F1, F2, F3) needs to be added to MA fuel rods so that the resulting flux is more evenly distributed. The calculation of reactor criticality shows that Np fuel rod design 4 and Am fuel rod design 1 have the best keff value (keff ≈ 1) among other designs. The burn-up of MA fuel rods produces a minimal probability of producing Tc99m, Sr89, Y90, Rh105, Ag111, I231, and Sm15 radiopharmaceutical waste, even less than 1 kg.
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%.