Article Per Year (5 Year)
p-Index From 2021 - 2026
0.444
P-Index
This Author published in this journals
All Journal BERKALA FISIKA SAINS DAN MATEMATIKA YOUNGSTER PHYSICS JOURNAL JITEK (Jurnal Ilmiah Teknosains) Journal of Physics and Its Applications
Ketut Sofjan Firdausi, Ketut Sofjan
Departemen Fisika, Fakultas Sains Dan Matematika, Universitas Diponegoro, Semarang
Agriculture, Biological Sciences & Forestry Astronomy Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Veterinary

Published : 24 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 6 Documents
Search
Journal : SAINS DAN MATEMATIKA

 1 
Pengamatan Efek Magnetooptis Menggunakan Interferometer Fahrurazi, Michelson; Firdausi, Ketut Sofjan; Budi, Wahyu Setia
JURNAL SAINS DAN MATEMATIKA Volume 14 issue 4 Year 2006
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (391.503 KB)

Abstract

ABSTRACT---The magnetooptic effect of transparency material such as aquarium glass, acrylic, and micro slide has been studied using Michelson Interferometer. The change of refractive index to magnetic field B is obtained by placement of samples in a coil applied on altered field 0-0,2 T. Results of interferometer test show that change of refractive index is linearly dependent on B for acrylic and slide. However, for aquarium glass, it is on B2 dependency. This result is agreement to previous experiment that the structure of acrylic and slide is formed more regular as B applied. Keywords: Magnetooptic effect, refraction index, interferometer
PENINGKATAN EMISI HIDROGEN MELALUI ATOM HELIUM METASTABIL DENGAN METODE LASER INDUCED PLASMA PADA SAMPEL ZIRCALOY Maliki, Maliki; Firdausi, Ketut Sofjan; Budi, Wahyu Setia
JURNAL SAINS DAN MATEMATIKA Volume 17 Issue 2 Year 2009
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5352.539 KB)

Abstract

ABSTRACT-Telah dilakukan  analisis  unsur  hidrogen  dari sampel  zircoloy  dan  sampel  batu  hitam melalui  pembangkitan  plasma  gelombang  kejut menggunakan laser Nd YAG (1064 nm, 8 ns, 68 mJ)  pada tekanan  rendah  dengan  mengalirkan  gas helium dan gas nitrogen sebagai  gas penyangga  di  dalam  ruang sampel.  Penelitian  dilakukan  untuk menunjukkan  pengaruh  atom  helium metastabil  pada  peningkatan  emisi hidrogen. Pengaruh atom  helium  metastabil pada  peningkatan emisi  hidrogen  ditunjukkan  dengan membandingkan  penggrmaan  gas  nitrogen  dan  gas  helium sebagai  gas  penyangga  pada  tekanan  2 torr dan  5 torr. Dari penelitian,  intensitas  emisi  hidrogen  menggunakan  gas  nitrogen  pada  tekanan  2 torr dan  gas  helium pada  5  torr untuk  sampel  zircaloy masing-masing  diperoleh  sebesar  317,0  cacah/detik  dan  4370,0  cacah/detik, sedangkan  pada  sampel  batu  hitam masing-masing  diperoleh  sebesar  297,6 cacah/detik  dan 694,0 cacah/detik. Hasil  ini  menunjukkan  atom helium metastabil  yang dihasilkan melalui helium sebagai  gas penyangga berpengaruh  terhadap  peningkatan  emisi  hidrogen  pada  sampel  zircaloy dan  batu  hitam. Kata  kunci : sampel zircaloy, sampel batu hitam, laser induced plasma, atom helium metastabil,  emisi hidrogen dan emisi helium.
Role of Saturated Fatty Acid (SFA) for Degradation of Oil Quality Firdausi, Ketut Sofjan
JURNAL SAINS DAN MATEMATIKA Volume 23 Issue 3 Year 2015
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (297.991 KB)

Abstract

In this study, the phenomena of natural polarization has been used as a preliminary test of vegetable oil quality. The formation of saturated fatty Acid (SFA) has been studied as a most responsible parameter for degradation of oil quality related to its expired limitation. The Oil quality was indicated by change of light polarization, and was measured using pair of polarizer-analyser. The result shows that the change of polarization can be used to indicate oil quality level related to its expiration date. This method also shows predicted SFA formation and apparently it is relative more powerful than standard parameters such as free fatty acid (FFA) test and peroxide value (PV) test. For future, this method has provided good prospect to evaluate the existence of the halal level of oil due to lard (pig oil). Keywords: natural polarization, vegetable oil quality, saturated fatty acid (SFA)
Natural Polarization and Electrooptics Comparison for Evaluation of Cooking Oil Total Quality Sugito, Heri; Firdausi, Ketut Sofjan
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (384.028 KB)

Abstract

In this study, the phenomena of natural polarization and electrooptics effect have been compared as alternative methods for evaluation of vegetable oil quality. The sample used in the experiment was various vegetable oils. The change of light polarization was measured using a pair of polarizer for natural polarization and in case of electrooptics with addition of induced external electric field through DC high voltage. The result has shown that both methods are able to indicate the level of various oil quality. The natural polarization is very useful for preliminary test of oil quality. In the other hand, the electrooptics has a good prospect as single physical indicator for vegetable oil quality.
PENGARUH INDUKSI MEDAN RADIO FREQENCY (RF) PADA DIPOL-DIPOL MOLEKUL AIR Firdausi, Ketut Sofjan; Kamil, Ahmad; Azam, Muchammad
JURNAL SAINS DAN MATEMATIKA Volume 17 Issue 1 Year 2009
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3722.702 KB)

Abstract

ABSTRACT-The non-linear optical property of rotary power of light polarization in water has been develop using the Radio-Freguency field (RF-Field). The RF-Field used in the experiment is produced by RF generator, and it supplies the frequency in the range betwen 6,04 to 14,56 MHz which then applies to the samples. The source of light with 632,8 nm-wavelength and 532 nm-wavelength are used to observe the change of range polarization of the light after it passes througt the samples.  Three modes of the direction of the electric field of light are chosen 0o (E//) (E of light is parallel to E of RF-Field), and 90o (E ) (E of light is perpendicular to E of the RF-Field) in order to determinate the optimal change of the angle of the polarization β. The values of β is measured as a function of RF-Field,  , where ωRF is the angular frequency of RF-Field and  BRF is the magnitude of magnetic field measured in the center of the coil which is assumed to be homogeny in the circumstances of the samples. The results of the experiment show that the degrees of change of the polarization direction, η is largest at the E3 mode. It shows also that at small wavelength of light we obtain the larger η, which is indicated the higher frequency of liglt will more induce the dipoles of molecules of the samples. Keywords:  non- linear optics, polarization angle, rotary power
Learning Vector Quantization Pada Pengenalan Pola Tandatangan Mubarika, Sofia; Munir, M.; Firdausi, Ketut Sofjan; Widarto, Widarto
JURNAL SAINS DAN MATEMATIKA Volume 14 issue 4 Year 2006
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (576.971 KB)

Abstract

ABSTRACT---In this paper, we analyze and compute distribution of thermal neutron flux in core of Kartini’s Reactor using “Swadaya” detector, both for axial (function of z) and radial (function r) direction. First, “Swadaya” detector is calibrated by activation plate method, which the output from detector is current. The result of calibration is thermal neutron flux (ф) dependent on current (I) that can be written as ф = 4,57x1020I - 2,74x1011. Distribution for neutron thermal flux for axial direction and radial direction respectively Ф = 5,10 x 1012 + 5,99 x 1013 and ф = 1.08 x 1012 + 1,00 x 103 which in reactor core ф has largest value in center position for radial direction.   Keywords: flux neutron distribution, nucleus reactor, Swadaya detector
Co-Authors Ahmad Kamil Ali Khumaeni Aziel Nimrod Febriyanto Azzahroh, Muffaricha Ekasari Ekasari Fajri Inayat Henik Rahmawati, Henik Heri Sugito I. Afiefah Izzah Afiefah M. Munir Maliki Maliki Michelson Fahrurazi Much Azam Much. Azam Muchammad Azam, Muchammad Nidia Kharisma Putri Nurhasanah, W Dewi Nurhasanah, Wahidatun Dewi Nyadaniati Simbolon Priyono Priyono Qidir Maulana Rahmawati, Aidah Ririn Widya Septianti S. Suryono Soesanto, Qidir Maulana Binu Sofia Mubarika Haryana Syifa Azahra Tiwiyaningsih, Tiwiyaningsih Ulfa Maftukhah Very Richardina Very Richardina Wahyu Setia Budi Wahyuni Wahyuni Winarno Winarno Zaenul Muhlisin