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All Journal BERKALA FISIKA Sainstek : Jurnal Sains dan Teknologi
K. Sofjan Firdausi
Jurusan Fisika, Fakultas Sains dan Matematika, Universitas Diponegoro Semarang
Computer Science & IT Physics Other

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Studi Radiografi Makro Dengan Variasi Jarak Sumber Sinar-Bayangan (SID) dan Ukuran Fokus Terhadap Pembesaran Bayangan Suriansyah, Nanang; Setiawati, Evi; Firdausi, K. Sofjan
BERKALA FISIKA Vol 10, No 4 (2007): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

The dependence of radiograph magnification (M) on the ratio focal spot size to object ( has been studied. The object shape like a coin made from iron which different diameter and variation focal spot size have been used. The experiment condition were set up at the distance of the object to the film of 0 cm (object stick the film) and 45 cm, with the tube voltage of 50 kV, tube’s current of 100 mA, and time of 0.04 s. The results show that the increasing of (leads to the increasing of (M) when the distance of the object to the film is more than 0 (b>0).   Keyword: focal spot, SID, magnification radiograph
ELECTROOPTIC CHARACTERISTICS OF COLLOIDAL SILVER SOLUTIONS USING TRANSVERSE ELECTROMAGNETIC MODE OF INCOMING LIGHT Firdausi, K. Sofjan; Setyoningrum, Aqilatul F.D.; Tiwiyaningsih, Tiwiyaningsih; Rahmawati, Aidah; Richardina, Very; Khumaeni, Ali; Sugito, Heri; Soesanto, Qidir M.B; Azam, Much
BERKALA FISIKA Vol 23, No 3 (2020): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

In this paper, we demonstrated new electro-optics characteristics of silver nanoparticle solution (NPP) using  linear  light  polarization.  The  electro-optical  properties  of  NPP  solution  were  obtained  by measuring changes in the polarization of light in the transverse electromagnetic (TEM) mode, in which the  source  light  is  made  linearly  polarized  at  0˚  and  90˚to  the  axis  of  polarizer.  NPP  samples  were obtained by laser ablation method and electro-optical properties were obtained through high voltage DC 0-9 kV with light source from green laser pointer (532 nm). The results showed that colloidal silver solution  in water  at  an angle  mode  of  0˚,  strongly  suspected  to  show  active  Plasmon  resonance at a concentration area of 3-5 ppm, with a peak of polarization at a concentration of 4.6 ppm. In the 90˚ mode, it is assumed that the colloidal silver solution is resonant inactive, the change in polarization is caused  only  by  a  combination  of  natural  polarization  and  electro-optical  polarization.  The  study  of changes in the polarization of light through electro-optical effects on silver solutions is very interesting to  be developed  further  using other  particles,  because  it  can provide  a  more  comprehensive  answer. This method also contributes science to the new  perspective of understanding the interaction of light with matter, especially colloidal silver solutions, and the like.Keywords: Light polarization, electro-optics effect, colloidal silver solution 
EVALUASI AKURASI PENGUKURAN UNTUK PERUBAHAN POLARISASI KECIL DI UDARA Firdausi, K. Sofjan; Winarno, Winarno; Hapsari, Berliana Y.
BERKALA FISIKA Vol 28, No 1 (2025): Berkala Fisika
Publisher : BERKALA FISIKA

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Secara umum, udara dianggap sebagai medium non-optis aktif berdasarkan sifat kiralitas molekulnya, dan sering digunakan sebagai referensi nol praktis dalam pengukuran aktivitas optis. Penelitian ini bertujuan untuk menguji akurasi pengukuran aktivitas optis pada sampel udara serta mengidentifikasi ralat sistematis yang mungkin timbul dari penggunaan polarimeter sederhana. Sumber cahaya dengan panjang gelombang 635 nm, 532 nm, dan 405 nm digunakan dan dipolarisasi linier, dengan variasi sudut polarisator dari 0° hingga 90° dalam kenaikan 5°. Perubahan sudut polarisasi diukur menggunakan analisator digital dengan skala terkecil 0,01°. Hasil menunjukkan adanya ralat sistematis rata-rata sebesar 0,036°, yang kemungkinan disebabkan oleh ketidaksejajaran sumbu antara polarisator dan analisator. Selain itu, deviasi pengukuran antara –0,04° hingga 0,12° diduga berasal dari kombinasi noise elektronik dan kesalahan paralaks. Meskipun secara teoritis tidak terjadi rotasi, karena udara dan kuvet bersifat non-optis aktif, hasil eksperimen menunjukkan adanya ambang sensitivitas sistem dalam mendeteksi rotasi sudut, yang mencerminkan adanya ralat sistematis tetap serta keterbatasan resolusi alat ukur.
Co-Authors Agustina Setyaningsih Ahmad Kamil Ali Khumaeni Anis Nila Kusuma Arif Fahmi ARIFAH ARIFAH Bunawas Bunawas Catur Edi Widodo Choirul Anam AM Diponegoro Dro Dwi Lego Dwi Satoto Edi Trijono B. S. Eko Sugiyanto Evi Setiawati Hadiyati Idrus Hapsari, Berliana Y. Hari Wibowo Heri Sugito Indras Marhaendrajaya Indri Setiani Istianah Istianah Jatmiko Endro Suseno Krisno Prabowo Lilik Eko Jatwiyono Moh. Yusron Mohammad Munir Much Azam Much. Azam Muchammad Azam, Muchammad Muhamad Adi Nanang Suriansyah Nina Khaerani Nina Widyastuti Prayitno Abadi Rahmadi Setyawan Rahmawati, Aidah Respita Sulistyo Risprapti Prasetyowati Setyoningrum, Aqilatul F.D. Sirojudin Sirojudin Sisca Silvani Soeleman Soeleman Soesanto, Qidir M.B Sulung Edy Nugroho Sumariyah Sumariyah Sutiah Sutiah Thithit Romadhona Tiwiyaningsih, Tiwiyaningsih Ummi Kaltsum Very Richardina Wahyu Adi Wibowo Wahyu Setia Budi Winarno Winarno