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Respon Non Linier Sifat Optis Larutan MgSO4 Firdausi, K. Sofjan; Azam, Much.; Romadhona, Thithit; Abadi, Prayitno
BERKALA FISIKA Vol 9, No 3 (2006): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

A response of nonlinear optic of several salt solutions in external magnetic field has been studied. An altered magnetic field varies from 0 until 0,2T used to induce samples, and then change of polarization angle b is measured by polarizators, where the direction propagation of laser is perpendicular to the direction of B. Various concentration of solution is used at 5% until 35%. Our experiment shows that the graphs of b vs. B are still linear for mineral water and NaCl solution. However, for MgSO4 solution, we obtained polynomial tendency of this graph. At 20% until 35% of concentration of this solution it has polynomial in third order. Keywords: Nonlinear optics, change of polarization angle, external magnetic field.
Simulasi Prediksi Sintilasi Ionosfer Menggunakan Aplikasi Matlab Dengan Metode Regresi Logistik Mukarom, Muhammad Alzed; Ahmad, Umar Ali; Abadi, Prayitno
eProceedings of Engineering Vol. 10 No. 1 (2023): Februari 2023
Publisher : eProceedings of Engineering

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Abstract

Abstrak—Sintilasi ionosfer menjadi permasalahan yang mengganggu frekuensi radio yang ditransmisikan oleh satelit GNSS (Global Navigation Satellite System). Peran satelit GNSS dapat memberikan berbagai macam informasi data dan mendapatkan data dengan mudah seperti informasi posisi. Akibat dari sintilasi terhadap satelit GNSS menjadi tidak stabil dan informasi jadi tidak tersampaikan. Faktor sintilasi ionosfer yang dipengaruhi oleh kecepatan (v), aktivitas matahari (F10.7), dan aktivitas geomagnetik (Kp). Penilitian tugas akhir ini membutuhkan pemodelan untuk memprediksi terjadinya sintilasi ionosfer sesaat setelah matahari terbenam. Penelitian ini menggunakan regresi logistik untuk membuat pemodelan terjadinya sintilasi ionosfer. Data sebanyak 427 poin pada setiap parameter dipartisi 70% untuk data latih dan 30% untuk tes data logistik yang digunakan. Metode ini dilakukan dengan mengkombinasikan berbagai prediktor kedalam pengujian. Dari hasil latih model regresi logistik menggunakan parameter v sebagai masukan mendapatkan akurasi hasil 84,3750%, kombinasi v dan F10.7 mendapatkan akurasi hasil 84,3750%. Kombinasi v dan Kp mendapatkan akurasi hasil 82,0313%. Kombinasi hasil terbaik dari latih dan tes adalah kecepatan dan aktivitas matahari. Nilai akurasi termasuk konsisten tidak memiliki perbedaan yang signifikan.Kata kunci— sintilasi, F10.7, Kp, kecepatan, regresi
Observations of Ionospheric Conditions Over Pontianak During The Partial Solar Eclipse Suraina; Abadi, Prayitno; Yolanda Putra, Angga; Puannandra Putri, Gerhana; Nurmali, Dadang; Nurdiansah, Lambang; Rakhman, Arif; Ednofri; Muzirwan
Indonesian Journal of Aerospace Vol. 22 No. 2 (2024): Indonesian Journal Of Aerospace
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/ijoa.2024.2942

Abstract

Solar energy plays a significant role in creating ionospheric layers through photoionization. However, when a solar eclipse occurs, the ionizing radiation from the sun will be obstructed by the moon, resulting in a decrease in ionization processes and a depletion of ionospheric plasma density. Our research examines the effects of two partial solar eclipse events that occurred on December 26, 2019 (Eclipse 1) and April 20, 2023 (Eclipse 2) over Pontianak. We observed changes in foF2 and TEC during these events. Our observations show that foF2 and TEC decreased at the start of a partial eclipse but returned to normal once the eclipse ended. The maximum decrease in foF2 observed was 1.88 MHz for Eclipse 1 and 1.26 MHz for Eclipse 2, while the decreases in TEC were 5.68 and 12.81 TECU for Eclipse 1 and 2 respectively. We noted that geomagnetic activity was quiet during both eclipses, indicating that the reduction in ionospheric parameters (TEC and foF2) is affected by the solar eclipse. During a solar eclipse, the decrease in ionization intensity results in a reduction in electron numbers in the ionospheric layers, leading to a reduction in TEC and foF2.