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Synthesis and Characterization of High Conductivity Polyaniline Prepared at Room Temperature Budi, Setia; Puspa Rini, Eka; Paristiowati, Maria; Imaduddin, Agung; Syafei, Devi
Chemistry and Materials Vol. 1 No. 1 (2022)
Publisher : Pusat Inovasi Sains

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1139.858 KB) | DOI: 10.56425/cma.v1i1.21

Abstract

In this study, polyaniline was successfully synthesized using an oxidative polymerization method at room temperature. The polymerizations were carried out with and without stirring process under ultraviolet (UV) irradiation. The polyaniline was characterized by FTIR, XRD, SEM, SAA, and Four Point Probe. It is found that UV irradiation and stirring could increase the surface area and conductivity of polyaniline. The surface area obtained for stirred and unstirred polymerization were 37.9 m2/g and 29.0 m2/g, respectively. Moreover, conductivity values for stirred and unstirred polymerization were found as 1.22 S/cm and 1.08 S/cm respectively. This result shows that polyaniline synthesized by stirring treatment obtained uniform morphology, smaller size, greater crystallinity, higher BET surface area, and higher conductivity than that that of without stirring.
Synthesis and Characterization of Cu-Cr-O Phase with H2SO4 Solvent Using Sol-Gel Method Rangkuti, Yusridah; Humaidi, Syahrul; Maulid, Nurul; Imaduddin, Agung; Herbirowo, Satrio; Nugraha, Heri; Darsono, Nono
Journal of Technomaterial Physics Vol. 5 No. 1 (2023): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v5i1.10897

Abstract

This study used the cast-in-situ method to make concrete based on rice husk ash and pineapple leaf fiber. Rice husk ash and pineapple leaf fiber were used as the cement substitutes with different variations: 0%, 2.5%, 5%, and 7.5%. Parameters examined in this study included density, porosity, water absorption, flexural strength, and compressive strength using a universal testing machine and Material Testing equipment, which were then analyzed morphologically using SEM-EDX. The result showed a density of  2.510 × 103 − 2.451 × 103 kg/m3, porosity of 7.64 – 5.73 %, water absorption of 0.296 % – 0.243 %, compressive strength of 23.66 – 16.45 MPa, flexural Strength of 33.3 – 25.3 MPa. The morphological analysis showed that the rice husk ash and pineapple leaf fiber addition was responsible for the concrete's porous structure in this study has a porous structure. The EDX analysis result exhibited a high carbon percentage.
PENINGKATAN SUHU KRITIS PADA SINTESIS BAHAN SUPERKONDUKTOR MAGNESIUM DIBORIDA DENGAN VARIASI UKURAN PARTIKEL SERBUK MG Herbirowo, Satrio; Yuwono, Akhmad H.; Utomo, Edy P.; Syafrizal, Syafrizal; Imaduddin, Agung
Jurnal Rekayasa Mesin Vol. 14 No. 3 (2023)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/jrm.v14i3.1651

Abstract

Studying the evolution of the MgB2 superconductor manufacturing process to improve critical temperature is important. The solid-state approach was used in this work to create a low-cost MgB2 superconductor. Variations in the purity of Boron were used as control parameters to evaluate the impact of dry milling on the production of the MgB2 bulk and low-temperature electrical properties. A 2:1 stoichiometric ratio of magnesium and boron powder was weighed and ground for 30 minutes. The ground powder was compressed and sintered for one hour at 1073 K. We were able to confirm through XRD and SEM research that the small particle size improved the MgB2 phase fraction and increase crystallite size in the production of the MgB2 sample. At 1073 K and 200 um of Mg, the sample sintered produced an MgB2 phase of 99.3%. The critical onset temperature (Tc-offset) improved from 39 to 40K, respectively.
Experimental comparison of air, oil, and liquid nitrogen cooling media on the efficiency of a single-phase transformer Nugraha, Heri; Imaduddin, Agung; Priandana, Eka Rakhman; Hermawan, Asep Dadan; Darsono, Nono; Pramono, Andika Widya; Syahid, Adi Noer; Palaloi, Sudirman; Herbirowo, Satrio; Hendrik, Hendrik
International Journal of Electrical and Computer Engineering (IJECE) Vol 16, No 1: February 2026
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v16i1.pp25-35

Abstract

Transformers are critical component in electric power system, where minimizing energy losses is essential for efficiency and reliability. While ideal transformers operate with zero losses, practical transformers dissipate energy through winding and core losses caused by resistive heating. This study investigates the impact of three cooling media with ambient air, mineral oil, and liquid nitrogen on the efficiency and thermal performance of a 1 kVA single phase copper wound transformer. The experiment applied a resistive load under each cooling condition, recording input and output parameters using a HIOKI power meter model PW3360. Thermal behavior was monitored using infrared thermography and thermocouples. Copper winding resistivity was evaluated using a four-point probe within a cryogenic magnet system. The results show that liquid nitrogen cooling significantly reduced copper resistivity due to low-temperature conditions, achieving a transformer efficiency of 89.9%. Oil cooling improved efficiency to 86.0%, compared to 80.7% with air cooling. Although liquid nitrogen provided the greatest efficiency enhancement, its practical use is limited due to handling complexity and cost. In contrast, oil cooling offers a more feasible and effective solution for improving transformer performance in real world applications. These finding provide valuable insight for optimizing transformer thermal management strategies in power systems.