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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

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Journal : journal of physics and its applications

 1 
Determination of relative dissociation energy from electro-optics as a new single-proposed parameter of vegetable oil quality Ketut Sofjan Firdausi; Izzah Afiefah; Heri Sugito; Ririn Widya Septianti; Very Richardina; Qidir Maulana Binu Soesanto; Much Azam
Journal of Physics and Its Applications Vol 2, No 1 (2019): November 2019
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v2i1.5181

Abstract

In this report, we study the electro-optics effect on cooking oil to obtain the relative dissociation energy as a new single proposed parameter of oil quality. The sample was canola oil which had been heated in 0.5 hours, 2 hours and 4 hours. The light source used in the experiment was a green pointer laser with a wave length of 532 nm. The sample was applied to a potential difference from 0 to 9 kV to obtain the electro-optics effect in form of the change of the polarization angle Dq as function of potential difference DV. The relative dissociation energy was obtained from the fitting data of the relative Lenard-Jones potential energy curves represented by change of polarization per unit change of potential difference, Dq/DV. The result shows that the relative dissociation energy is reduced as the oil quality decreased after heated. The relative dissociation energy provides simple physical understanding about electro-optics effect on cooking oils. The study of electro-optics polarization that represents relative Lenard-Jones potential energy is a new but somewhat intuitive, which can be further improved and emphasized for grouping, mapping, and determining various cooking oil quality and halal food due to the lard contamination.
Mapping Various Cooking Oil using Fluorescence Polarization Ketut Sofjan Firdausi; I. Afiefah; Heri Sugito; Much. Azam
Journal of Physics and Its Applications Vol 1, No 1 (2018): November 2018
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v1i1.3913

Abstract

In this report we have succeeded to map various cooking oils using change of fluorescence polarization. Various cooking oils consisted of several vegetables oils and animal oils (chicken oil and lard) were used in the experiment, and some oils were measured in two different times. The change of polarization angle &tetha; was measured as the difference between linear polarized green pointer laser as incoming light and fluorescence light using a pair of polarizers. The direct measurement of fluorescence polarization gives a new unique result of critical polarizer’s angle φc that can group vegetable cooking oils into group 1 (at φc = 10o for VCO, olive, and soybean), group 2 (at φc = 20o for palm, corn and rice bran), group 3 (at φc = 30o for sunflower and canola), and also animals cooking oils into group 4 (at φc = 20o for chicken oil), and group 5 (at φc = 40o for lard). Mostly cooking oils can be distinguished using modified maps. The large difference φc and &tetha; of lard from vegetable oils provides an advantage to develop for testing halal oil due to lard contamination. The capability of this method has benefits, at least, as a complement and simple method in comparison to other expensive sophisticated instruments such as fluorescence spectroscopy or GCMS methods with their derivation’s instruments.
Characteristics of colloid silver solution based on changes in concentration and electric field using electrooptic equipment Heri Sugito; Ketut Sofjan Firdausi; Ali Khumaeni; Syifa Azahra
Journal of Physics and Its Applications Vol 4, No 1 (2021): November 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v4i1.12419

Abstract

Research on the characteristics of colloidal silver solutions based on changes in concentration and electric field using electrooptic devices has been carried out. The purposes of this study was to determine the characteristic of colloidal silver solution based on variations in concentration and electrooptic effects. Electrooptics work based on changes in the polarization angle of the sample. The sample used is a colloidal silver solution with various concentrations. The colloidal silver solution was obtained by laser ablation method and then dissolved in aquabidest. The light source used is a laser pointer with = 532 nm. The electric field applied to the sample is 0-9 kV. The results showed that colloidal silver solution at an angle of 0º showed active plasmon resonance at the peak of polarization with concentrations of 1.9 ppm, 2.28 ppm, and 3.8 ppm. An angle of 90º also shows active plasmon resonance at the peak of polarization with a concentration of 3.8 ppm. From the results, it can be concluded that the characteristics of colloidal silver solution on change in the polarization angle due to an electric field show non-linier properties with increasing concentration.
Design of Integrated Polarizer to Evaluate Quality of Cooking Oil Based on the Fluorescence Polarization Method Heri Sugito,; Ketut Sofjan Firdausi
Journal of Physics and Its Applications Vol 1, No 1 (2018): November 2018
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v1i1.3915

Abstract

An integrated polarizer was designed as an alternative test tool to evaluate quality of cooking oils. Integrated Polarizer was composed of light source with wavelength of 532 ± 10 nm, polarizer, analyser, cuvette, electrodes, and high voltage source. In this research, the tool works based on the fluorescence polarization method. Measurements were made by observing the fluorescence polarization angle changes that occur and by applying an external electric field at the samples using high voltage of 0-9 kV in the parallel plate. The results show that the expired cooking oil has a greater polarization angle than the edible cooking oil. The results also show that the change in the polarization angle will increase in proportion to the increase of the heating time. The condition of saturated fatty acids in each sample has an effect on the change of polarization angle.
Characterization of Optical Properties of Colloidal Gold Solution based on Changes in Concentration using Light Polarization Method Winarno, Winarno; Firdausi, Ketut Sofjan; Soesanto, Qidir Maulana Binu; Khumaeni, Ali
Journal of Physics and Its Applications Vol 6, No 2 (2024): May 2024
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v6i2.22406

Abstract

This research was conducted to determine the effect of concentration on the characteristics of changes in the polarization angle of colloidal gold solutions. The method used in this research is natural polarization. The light source used was a green laser with a wavelength of 532 nm. The colloidal gold solution was obtained using the laser ablation method and then dissolved in aquabidest. The characteristics of changes in the angle of light polarization in the gold colloidal solution were obtained by varying the concentration of the gold colloidal solution (40 ppm, 30 ppm, 20 ppm, and 10 ppm). The results showed that gold colloids have optical activity because the orientation of the gold colloid molecules allows them to interact asymmetrically with linearly polarized light. In the range of concentration from 10 to 40 ppm, the polarization angle in gold colloids shows a linear pattern as a function of concentration. Within one month the colloidal gold sample showed stable properties. This method allows us to further analyze the quality of other types of colloids using the same method. This will improve our understanding of the interaction of polarized light with nanoparticles.
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