Article Per Year (5 Year)
p-Index From 2021 - 2026
0.659
P-Index
This Author published in this journals
All Journal JURNAL PENDIDIKAN TAMBUSAI Indonesian Physical Review Inovasi Fisika Indonesia (IFI)
Rahayu, Vira
Unknown Affiliation
Earth & Planetary Sciences Education Electrical & Electronics Engineering Materials Science & Nanotechnology Physics Social Sciences

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Memaksimalkan Kemampuan Berpikir Kritis melalui Mengidentifikasi Satuan Panjang dengan Bola Soal SDN Telaga Biru 8 Rahayu, Vira; Darmiyati, Darmiyati
Jurnal Pendidikan Tambusai Vol. 8 No. 3 (2024)
Publisher : LPPM Universitas Pahlawan Tuanku Tambusai, Riau, Indonesia

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

Abstract

Permasalahan yang mendasari penelitian ini ialah kemampuan dalam berpikir kritis aktivitas siswa serta hasil belajar khususnya mata pelajaran matematika materi satuan panjang. Sebab itu, itu perlunya ada model pembelajaran untuk bisa meningkatkan keterampilan berpikir kritis, aktivitas belajar serta hasil belajar. Model pembelajaran yang digunakan adalah model pembelajaran problem based learning yang dikombinasikan dengan example non example dan snowball throwing. Metode yang dipakai pada penelitian ini ialah kuantitatif dan kualitatif yang menggunakan jenis penelitian tindakan kelas (PTK). Subjek penelitian ini ialah siswa kelas II SDN Telaga Biru 8, dengan total siswa 26 orang. Hasil penelitian ini menunjukkan bahwa aktivitas pendidik pada siklus I mencapai skor 40 pada siklus II meningkat menjadi 42, kemudian pada aktivitas peserta didik mengalami peningkatan, yang mana pada siklus I hanya mencapai 69% pada siklus II meningkat menjadi 100%, kemampuan berpikir kritis pada pertemuan hanya mencapai 42% pada pertemuan 3 meningkat menjadi 88%. Ketuntasan klasikal hasil belajar pada siklus 1 hanya mencapai 42% dan meningkat pada siklus II menjadi 81%.
SINTESIS KOMPOSIT NANO PANI/Fe3O4 KONDUKTIF BERBASIS PASIR ALAM Hamid, Abd Basith; Sholichah, Nikmatin; Rahayu, Vira; Ardimas, Ardimas; Fadhli, Ulfa Mahfudli
Indonesian Physical Review Vol. 4 No. 2 (2021)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v4i2.94

Abstract

Polyaniline is a polymer material that has unique physical and even chemical properties, especially in its electrical properties. PANi synthesis can be carried out by chemical and electrochemical oxide reaction methods. The purposes of this study are to synthesize PANi and PANi / Fe3O4 composites by chemical oxide reactions and measure their conductivity. This research begins with the synthesis of iron oxide (Fe3O4) from natural iron sand and then followed by the synthesis of PANi / Fe3O4 composites using copreticipitation method. The Fe3O4 crystal phase was determined by using XRD, while the vibrational mode and morphology of the PANi / Fe3O4 nanocomposite was observed using FTIR and SEM. The conductivity properties were measured using a LCR meter. Furthermore, the conductivity properties were measured using a LCR meter and the result reveals a greater conductivity value as increasing the concentration of Fe3O4, the highest conductivity value of 3.1 mS/cm is known by the sample with an iron oxide concentration of 1 %. While the samples with a concentration of 0.5 % of iron oxide has conductivity values  of 2.8 mS/cm and pure PANi of 2.1 mS/cm. Due to its properties such  to inert to the environment and having conductive properties, the obtained PANI / Fe3O4 composite can be employed as a super capacitor electrode.
ANALYSIS OF THE EFFECTIVENESS OF METAL COVER IN PREVENTING RADIATION LEAKAGE IN MICROWAVE-BASED GASIFICATION REACTOR Rahayu, Vira; Ratnasari, Tri; Rahmatullah, Muhammad Arif; Pramono, Yono Hadi; Yudoyono, Gatut
Inovasi Fisika Indonesia Vol. 14 No. 3 (2025): Vol 14 No 3
Publisher : Prodi Fisika FMIPA Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/ifi.v14n3.p404-411

Abstract

Abstract Microwave-assisted gasification, which converts biomass and plastic waste into syngas, has significant promise for the production of clean renewable energy. This technology has the potential to reduce reliance on fossil fuels and address waste management challenges. Operational safety, particularly with microwave leakage, is a significant issue due to stringent standards for microwave exposure. This study evaluates the effectiveness of several metallic materials as microwave shields in microwave gasification reactors. This study investigates the effectiveness of 2 mm thick metal sheets made of copper, aluminum, iron, and stainless steel in reducing microwave leakage at a frequency of 2.45 GHz. Experimental results indicated that copper and aluminum are particularly effective shields. Copper attained a remarkable leakage reduction of 99.53% (from 105.6 W/m2  to 0.5  W/m2) while aluminum reached a decrease of 97.35% (from 105.6 W/m2 to 2.8 W/m2). Efficient reflection and absorption of microwave energy are facilitated by the extremely low skin depth values of both materials, which is consistent with their high effectiveness. However, iron and stainless steel also demonstrated a strong capacity to reduce leakage, with an efficacy of 89.96% (reducing leakage to 10.6 W/m2 ) and 73.86% (reducing leakage to 27.6 W/m2). Still, their performance was influenced by more complex magnetic properties. These results indicate that copper and aluminum are ideal choices for primary microwave shielding applications in gasification reactors. Conversely, iron and stainless steel, while less efficient as primary shields, offer excellent mechanical strength and corrosion resistance, making them suitable for auxiliary structural components. Therefore, a hybrid design integrating a thin shielding layer of copper or aluminum onto these structural elements is proposed for optimal microwave containment. This study provides crucial insights for the design of safer and more efficient microwave gasification reactors, thereby supporting the development of responsible renewable energy technologies.
Co-Authors Ardimas, Ardimas Darmiyati Fadhli, Ulfa Mahfudli Gatut Yudoyono Hamid, Abd Basith Rahmatullah, Muhammad Arif Ratnasari, Tri Sholichah, Nikmatin Yono Hadi Pramono