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121	Material Physics	ABS-105
Microstructural and Mechanical Characterization of Cr-based Precipitate-Strengthened Alloys Risma Yulita Sundawa (a), Eni Sugiarti (b), Asep Ridwan Setiawan (a), Hermawan Judawisastra (a), Safitry Ramandhany (b,c), Nurul Latifah (b), Kurotun Aini (b,c), Muhamad Sar^i (b) (a) Faculty of Mechanical and Aerospace Engineering, ITB (b) Research Center for Energy Materials, BRIN (c) Faculty of Mathematics and Natural Sciences, UI Abstract Precipitate-strengthened Cr-based alloys have recently emerged as promising candidates for advanced high-temperature applications, offering superior economic value compared to Ni-based alloys and improved mechanical properties and oxidation resistance compared to Fe-based alloys. Inspired by the excellent properties of the \gamma-\gamma^{^} system in Ni-based alloys, alloy composition and heat-treatment parameters in this study were simulated using OpenCALPHAD to obtain \beta-Cr and \beta^{^}-NiAlphases. This study focuses on the development of precipitate-strengthened Cr-based model alloys with the composition Cr-20Fe-10Ni-10Al (at.%). The alloys were synthesized using an arc-melting furnace and subsequently subjected to a two-step controlled heat treatment: solution treatment at 1400^{o}C followed by aging at 800^{o}C and rapid quenching. The microstructure, phase formation, and hardness of the alloys were systematically analyzed using SEM-EDS, XRD, and Vickers hardness testing. Keywords: Alloys, High-temperature materials, Cr-based, Heat-treatment, Precipitates strengthening Share Link | Plain Format | Corresponding Author (Risma Yulita Sundawa)

122	Material Physics	ABS-109
Impedance Spectroscopy Study of LaFe0.9Mn0.1O3 Material for Humidity Sensor Applications Umairah1, Nayla Ramadhani1, Nova Nur Elisa Dewi2, Djoko Triyono2*, Iwan Sugihartono1** 1Program Studi Fisika, FMIPA, Universitas Negeri Jakarta, Rawamangun, Jakarta, 13220, Indonesia 2Departement of Physics, FMIPA, Universitas Indonesia, Depok, 16424, Indonesia Abstract This study examines the structural properties, elemental composition, and impedance response of LaFe0.9Mn0.1O3 material under varying relative humidity (RH) conditions for humidity sensor applications. The material was successfully synthesized using the sol-gel method. Structural characterization using X-ray Diffraction (XRD) confirmed that LaFe0.9Mn0.1O3 has an orthorhombic crystal structure with space group Pnma, in agreement with the Inorganic Crystal Structure Database (ICSD) No. 98-016-4083. Elemental composition analysis using X-ray Fluorescence (XRF) verified the presence of La, Fe, Mn, and O elements with weight percentages of 57.24%, 20.71%, and 2.26%, respectively, indicating good agreement with the expected stoichiometry. The electrical behaviour of the material was evaluated using electrochemical impedance spectroscopy (EIS) at different humidity levels, including low, ambient, and high RH conditions. The results show that the impedance response of LaFe0.9Mn0.1O3 changes significantly with variations in humidity, indicating good sensitivity to RH. Overall, the material exhibits a well-defined orthorhombic perovskite structure, appropriate elemental composition, and strong humidity-dependent electrical properties. These characteristics suggest that LaFe0.9Mn0.1O3 is a promising candidate for humidity sensor applications with good response and stability. Keywords: LaFe0.9Mn0.1O3- Humidity sensor- Impedance spectroscopy- Perovskite oxide- Sol-gel synthesis. Share Link | Plain Format | Corresponding Author (Iwan Sugihartono)

123	Material Physics	ABS-115
Effect of Deoxygenation on the Porosity and Morphology of Hydrazine-Reduced Graphene Oxide Derived from Graphite Lalu Saefullah (a,b), Masruroh (a*), Dionysius J. D. H. Santjojo (a), Istiroyah (a) (a) Department of Physics, Universitas Brawijaya, Jl. Veteran No.10-11, Malang, East Java Timur 65145, Indonesia (b) Military Weapons Engineering Technology Study Program, Poltekad Kodiklatad Malang, Junrejo, Kota Batu, Jawa Timur 65324, Indonesia *Corresponding Author e-mail: ruroh[at]ub.ac.id Abstract Synthesizing reduced graphene oxide (rGO) with tailored structure and controlled porosity is critical for advanced materials. This study synthesizes rGO from graphite via a modified Hummers method followed by hydrazine hydrate reduction, comprehensively analyzing the correlations between elemental composition, microstructural evolution, and porosity. Initially, graphite was oxidized to graphene oxide (GO) using strong intercalating agents (H2SO4 and KMnO4), then thermochemically reduced to restore the sp2 carbon lattice. SEM characterization confirmed an inhomogeneous layered morphology resulting from partial exfoliation, featuring a Gaussian flake size distribution with a 2.42 um mean diameter. EDS analysis revealed a composition dominated by 71.02% carbon and 26.89% oxygen. FTIR validated this deoxygenation degree, demonstrating significant attenuation of oxygenated functional groups (C=O, C-O) alongside intensified aromatic C=C bands. Based on structural modeling, the synthesized rGO achieved an exceptionally high total porosity of 79.22%. This high void density and open-channel formation directly correlate with the evolution of oxygen-containing groups and gases during reduction, effectively inhibiting graphene sheet restacking and validating established pore-formation models. In conclusion, integrating the Hummers method with hydrazine reduction effectively produces rGO with a superior porosity profile and an optimal deoxygenation ratio, positioning it as a highly promising candidate for conductive materials and advanced energy storage matrices. Keywords: Reduced Graphene Oxide, Hummers Method, Hydrazine, Porosity, Elemental Composition Share Link | Plain Format | Corresponding Author (Lalu Saefullah)

124	Material Physics	ABS-116
Electromagnetic Properties of Oriented Carbon Fiber/Co(0.6)Cu(0.4)Fe2O4/Epoxy Composites for Microwave Absorption Applications Ahmad Alfiannur Utama(a*), Jan Setiawan(b*), Budhy Kurniawan R (a*) (a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia (*bkuru[at]fisika.ui.ac.id,*ahmad.alfiannur51[at]ui.ac.id) (b) Research Center for Advanced Materials, National Research and Innovation Agency, Kawasan Sains Teknologi B.J. Habibie, Serpong 15314, Indonesia *jan.setiawan[at]brin.go.id Abstract Lightweight microwave-absorbing materials have attracted increasing attention for electromagnetic interference shielding and radar-absorbing applications due to their excellent electromagnetic attenuation capability and structural advantages. In this study, Co(0.6)Cu(0.4)Fe2O4/carbon fiber/epoxy composites were fabricated to investigate the influence of carbon fiber orientation on electromagnetic properties and microwave absorption performance. The electromagnetic parameters were characterized using a vector network analyzer and analyzed through the Nicolson-Ross-Weir method to determine complex permittivity, complex permeability, attenuation constant, impedance matching characteristics, and reflection loss behavior within the microwave frequency range. The results revealed that carbon fiber orientation significantly affected dielectric response and attenuation capability. Improved fiber alignment enhanced conductive network formation and interfacial polarization between carbon fiber, Co(0.6)Cu(0.4)Fe2O4, and epoxy matrix, resulting in higher dielectric loss performance. Meanwhile, Co(0.6)Cu(0.4)FeFe2O4 contributed to magnetic loss mechanisms through magnetic resonance interactions, producing synergistic dielectric-magnetic attenuation effects. The optimized composite exhibited a minimum reflection loss of approximately -36.7 dB and an effective absorption bandwidth below -10 dB over several microwave frequency regions. Enhanced microwave absorption performance was attributed to conductive loss, interfacial polarization, magnetic resonance, multiple scattering effects, and improved impedance matching characteristics within the composite structure. Keywords: Carbon fiber orientation, Microwave absorption, Impedance matching, Stealth technology, based ferrite Share Link | Plain Format | Corresponding Author (Ahmad Alfiannur Utama)

125	Material Physics	ABS-119
Enhanced Wicking and Absorbency Performance of Reusable Period Underwear Using Functional Gusset Development for Reusable Menstrual Underwear Yoga Matin Albar1*, Yeni Sesnawati1, Gusman Santika2 , Vina Bekti Utami3 and Yoel Santo Andrianus Sormin4 1 Fashion Education Study Program, Faculty of Engineering Universitas Negeri Jakarta, Jakarta, Indonesia 2 Chemistry Education Study Program, Faculty of Mathematics and Natural Sciences Universitas Negeri Jakarta, Jakarta, Indonesia 3 Physics Education Study Program, Faculty of Mathematics and Natural Sciences Universitas Negeri Jakarta, Jakarta, Indonesia 4 Garment Manufacturing Engineering Study Program, Akademi Komunitas Industri Tekstil dan Produk Tekstil Surakarta, Central Java, Indonesia Abstract Reusable menstrual underwear has emerged as a sustainable alternative to disposable menstrual hygiene products- however, commercially available products still exhibit limited absorbency and insufficient leakage protection. This study developed a multilayer functional gusset integrating weft-knitted spacer fabrics and electrospun sodium alginate/polyvinyl alcohol (NaAlg/PVA) nanofibrous membranes to improve absorbency, moisture transport behavior, and leakage resistance. Fifteen three-thread spacer fabric structures were engineered using a computerized 14-gauge flat knitting machine and characterized through moisture management and absorbency analyses. Electrospun NaAlg/PVA nanofibrous membranes were fabricated under optimized electrospinning conditions and integrated into multilayer gusset assemblies together with polyurethane-laminated waterproof barrier layers. Moisture transport properties were evaluated using the AATCC 195 method, while absorbency capacity and rewet behavior were assessed using a modified FEMTECHMAS-6513-1:2023 protocol. Results demonstrated that all developed spacer structures achieved effective one-way moisture transport behavior, with Group B structures exhibiting superior directional liquid transfer performance. Among all evaluated structures, specimen B2 demonstrated the best overall performance, achieving a one-way transport capacity index of 477.72, maximum wetted radius ratio of 2.31, and absorbent capacity of 20 mL despite lower thickness and GSM than commercially available reference materials. Integration of electrospun membranes into gusset assemblies further increased absorbency capacity to 51 mL while maintaining rapid moisture transfer and low rewet characteristics. Overall findings confirmed synergistic interaction between spacer knitted fabrics and electrospun nanofibrous membranes in enhancing fluid management efficiency for reusable menstrual underwear applications. Keywords: Textile material engineering, Electrospinning technology, Fluid transport performance, Multilayer absorbent structure, Sustainable wearable materials Share Link | Plain Format | Corresponding Author (Yoga Matin Albar)

126	Material Physics	ABS-122
Fast Microwave-assisted synthesis of Reduced Graphene Oxide Muhammad Hakeem Alvanneda (1), Salma Aridha Muflihah (2), Mohammad Yusuf Andhika Putra Wardhana (1), Akfiny Hasdi Aimon (2*), Lia Amelia Tresna Wulan Asri (1), Arie Wibowo (1) 1-Materials Science and Engineering Research Group, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Bandung 40132, Indonesia 2-Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10, Bandung, Jawa Barat 40132, Indonesia Abstract Graphene oxide (GO), a single layered carbon material with sp^2-bonded configuration, was synthesized via an oxidation-exfoliating process using the Tour method. The subsequent reduction to reduced graphene oxide (rGO) as carried out using microwave irradiation as a heat source at a power of 800 W with varying irradiation time (1, 3, and 5 minutes). The resulting materials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy to investigate the effect of irradiation time in crystal structure, morphology, and defect characteristics. XRD analysis confirms a clear structural evolution from graphite to GO and subsequently to partially reduced rGO. TEM images reveal thin, wrinkled sheet-like structures with varying degrees of transparency in both GO and rGO samples. Raman analysis further confirms the formation of GO and rGO through the presence of the characteristic D and G bands. Moreover, the gradual decrease in the ID/IG ratio with increasing microwave irradiation time suggests a reduction in defect density and the progressive restoration of sp^2 domains, indicating that the reduction process proceeds effectively. Keywords: Irradiation time, microwave energy, reduced graphene oxide, Tour method Share Link | Plain Format | Corresponding Author (Mohammad Andhika Wardhana)

127	Material Physics	ABS-136
Oxidation resistance of NiCrAlHf-YSZ as a thermal barrier coating system for nickel-based superalloy applications Nurul Latifah (a,b), Eni Sugiarti (a*), Djoko Triyono (b), Safitry Ramandhany (a,b), Kurotun Aini (a,b), Risma Yulita Sundawa (c), Muhamad Sar^i (a), Budi Prawara (a), Endro Junianto (a), Tubagus Suryaman (d), and Adhitya Trenggono (d) a) Research Center for Energy Materials, National Research and Innovation Agency (BRIN), Serpong, Indonesia *enis006[at]brin.go.id b) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia c) Department of Material Science and Engineering, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Bandung, Indonesia d) Department of Metallurgical Engineering, Faculty of Engineering, Universitas Sultan Ageng Tirtayasa, Banten, Indonesia Abstract Thermal barrier coating (TBC) systems are widely employed to improve the oxidation resistance of nickel-based superalloys operating at high temperatures. This study examines the oxidation resistance of NiCrAlHf-YSZ coatings applied to Inconel 625 and Hastelloy C-276 substrates during isothermal oxidation at 1000 C for 100 hours. The bond coat material, Ni-24Cr-7Al-0.4HfO2 (wt.%), was produced by mechanical milling, whereas 8 wt.% yttria-stabilized zirconia (8YSZ) served as the top coat. The bond coat and top coat were applied via high velocity oxygen fuel (HVOF) and air plasma spraying (APS), respectively. Microstructural and phase analyses were conducted using field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). The results showed that the NiCrAlHf-YSZ coating applied to Inconel 625 exhibited enhanced oxidation resistance compared to Hastelloy C-276, as evidenced by the reduced mass change and oxidation rate values of 1.06987 mg/cm2 and 2.48 x 10-9 g2cm4/s, respectively. The thermally grown oxide (TGO) layer between the bond coat and top coat was assessed to comprehend the oxidation behavior during high-temperature exposure. The enhanced oxidation resistance was associated with the formation of a stable and protective oxide layer. Keywords: Hastelloy C-276- Inconel 625- Oxidation- Thermal barrier coating Share Link | Plain Format | Corresponding Author (Eni Sugiarti)

128	Material Physics	ABS-143
Valorization of Terminalia catappa Fruit Waste into Activated Carbon through KOH-Assisted Pyrolysis Iwan Nugraha Gusniar, Agus Sutanto, Gunawarman, Nidya Chitraningrum, Eri Widianto, Alifah Naira Soraya, Rizal Hanifi, Kardiman, Siswadi a Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Limau Manis, Padang, West Sumatera, 25166, Indonesia. b Department of Mechanical Engineering, Faculty of Engineering, Universitas Singaperbangsa Karawang, Telukjambe Timur, Karawang 41361, Indonesia. c Research Center for Biomass and Bioproduct, National Research and Innovation Agency (BRIN), KST Soekarno, Cibinong, 16911, Indonesia. d Department of Physics, Faculty of Engineering, Universitas Singaperbangsa Karawang, Telukjambe Timur, Karawang 41361, Indonesia. Abstract Biomass derived carbon materials are increasingly considered as sustainable alternatives to conventional adsorbents due to their availability and low cost. In this work, Terminalia catappa fruit waste was utilized as a precursor to produce activated carbon via KOH assisted pyrolysis at 400 C and 800 C. Raman spectra show the characteristic D (1348 cm) and G (1595 cm) bands, representing disordered and graphitic carbon structures, respectively. The higher-temperature sample exhibits a more pronounced G band, indicating improved structural ordering, although defect related features remain evident. FTIR analysis reveals the presence of oxygen containing functional groups, including OH, CO, and C same C stretching associated with aromatic structures, with reduced intensity observed at higher temperature, suggesting enhanced carbon stabilization. Morphological observations confirm that higher pyrolysis temperature promotes more developed and interconnected pore structures. Elemental analysis further indicates that carbon is the dominant component, confirming effective biomass conversion. These results demonstrate that Terminalia catappa fruit waste can be converted into porous activated carbon through a simple and efficient process, with potential applications in environmental remediation, energy related fields, and microwave absorption materials. Keywords: Activated carbon, Terminalia catappa, KOH activation, pyrolysis, biomass valorization Share Link | Plain Format | Corresponding Author (Agus Sutanto)

129	Material Physics	ABS-145
ANALISIS PERFORMA ELEKTROKIMIA PADA PENGEMBANGAN ELEKTRODA AC@CCF SEBAGAI PERANGKAT SUPERKAPASITOR Aprilia Pramu Dhita1, a), Rike Yudianti2, b)Iwan Sugihartono1, c) 1Program Studi Fisika, FMIPA, Universitas Negeri Jakarta, Jl. Rawamangun Muka Raya, Rawamangun 13220, Indonesia a)pramudhitaaprilia[at]gmail.com b) rike001[at]brin.go.id c) iwan.sugihartono[at]unj.ac.id 2Pusat Riset Elektronika, Badan Riset dan Inovasi Nasional (BRIN), KST Sama^un Samadikun, Jalan Sangkuriang, Bandung 40135, Indonesia Abstract The active composite material consisting of activated carbon derived from oil palm empty fruit bunches and the metal oxide Copper Cobalt Ferrite (AC@CCF) was successfully synthesized using the hydrothermal method. Electrochemical analysis demonstrated that the AC@CCF composite electrode exhibited excellent capacitive performance due to the synergistic contribution of porous activated carbon and spinel ferrite CuCoFe2O4. Cyclic voltammetry results revealed quasi-rectangular curves with a large enclosed area and stable shape retention within the scan rate range of 5-100 mV/s, indicating high electrochemical reversibility and rapid ion diffusion. The porous structure of the activated carbon provided a large surface area and efficient ion transport pathways, thereby enhancing the interaction between the electrolyte and the electrode surface, while the presence of CuCoFe2O4 contributed to improved charge transfer and electrochemical stability. Furthermore, the AC@CCF electrode achieved a specific capacitance of 174 F/g at a current density of 0.1 A/g. The synergy between activated carbon and spinel ferrite effectively enhanced the energy storage capability and maintained stable performance at various scan rates, demonstrating its strong potential as a high-performance and sustainable supercapacitor electrode material. Keywords: supercapacitor, activated carbon, copper cobalt ferrite, empty fruit bunch. Share Link | Plain Format | Corresponding Author (Aprilia Pramu Dhita)

130	Material Physics	ABS-146
Effect of Quenching and Tempering Processes on the Microstructure, Hardness, and Wear Resistance of AISI 1045 Steel Imam Basori1, Akhid Septoaji1, Agung Premono1, Juliawati Alias2 1Department of Mechanical Engineering, Universitas Negeri Jakarta, Indonesia 2Faculty of Mechanical and Automotive Engineering Technology, Universiti Malaysia Pahang Al-Sultan Abdullah, Malaysia Abstract Steel is one of the most widely used metallic alloys in industries such as automotive, mining, construction, and manufacturing due to its favorable mechanical properties, including high hardness, wear resistance, and the ability to tailor its properties through heat treatment processes. This study investigates the effect of quenching and tempering treatments with different holding times on the microstructure, hardness, and wear behavior of AISI 1045 steel. The quenching process was conducted at 850 C using water as the cooling medium with holding times of 30 and 60 min, followed by tempering treatments with holding times of 30 and 60 min. The results revealed that the quenching treatment produced a martensitic microstructure characterized by fine and densely distributed needle like morphology. Increasing the holding time during quenching resulted in a more homogeneous and compact martensitic structure. Subsequent tempering transformed the martensite into tempered martensite, while longer tempering times promoted carbon diffusion and the formation of fine carbide precipitates. Hardness testing showed a significant increase in hardness after quenching, from approximately 205 HVN in the untreated material to 603 HVN and 669 HVN for holding times of 30 and 60 min, respectively. Following tempering, the hardness values decreased to a range of 536 to 575 HVN due to the reduction in martensitic brittleness. Wear test results indicated that the wear rate decreased after quenching. The untreated material exhibited a wear rate of 5.51, which decreased to 4.47 and 3.17 for quenching holding times of 30 and 60 min, respectively. However, the tempering process slightly increased the wear rate, although the increase was not significant. Overall, the results demonstrate that variations in holding time during quenching and tempering significantly influence the microstructure, hardness, and wear resistance of AISI 1045 steel. Keywords: AISI 1045 steel, heat treatment, quenching, tempering, martensite Share Link | Plain Format | Corresponding Author (IMAM BASORI)

131	Material Physics	ABS-165
SIFAT TERMOELEKTRIK LAPISAN TIPIS ZnO TERDOPING Fe PADA SUHU 30-50 C Auliya Rahmawati1,a), Rike Yudianti2,b), Iwan Sugihartono1,c) 1 Program Studi Fisika, FMIPA, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Jakarta Timur 13220, Indonesia a) auliyarahmawati1109[at]gmail.com, b) rike001[at]brin.go.id, c) iwan.sugihartono[at]unj.ac.id 2 Pusat Riset Elektronika, Badan Riset dan Inovasi Nasional BRIN, KST Samaun Samadikun, Jalan Sangkuriang, Bandung 40135, Indonesia Abstract Thin films of ZnO and Fe doped ZnO have been synthesized using the spray coating method on silicon substrates for thermoelectric applications. The results of Seebeck coefficient testing in the temperature range of 298-318 K show that Fe doped ZnO material has better performance compared to pure ZnO. The highest Seebeck coefficient value obtained is minus 41.24 micronV per K for ZnO, while Fe doped ZnO shows a larger absolute value which is minus 91.67 micronV per K. The negative Seebeck value indicates that both materials are n type semiconductors with electrons as the majority charge carriers. The current voltage I V characteristics show a linear relationship indicating ohmic contact behavior with higher current in Fe doped ZnO compared to pure ZnO. This increase is predicted to be due to the effect of Fe dopant addition. In addition, the addition of Fe dopant also affects the increase in the Seebeck coefficient and electrical conductivity values. Therefore, the effect of Fe dopant is believed to be able to improve the thermoelectric efficiency of ZnO thin films. Keywords: ZnO, Fe doping, thermoelectric, n type, Seebeck, I V Share Link | Plain Format | Corresponding Author (Auliya Rahmawati)

132	Material Physics	ABS-167
Synthesis of NMC 631 Cathode Using Technical and Analytical-Grade Materials for Lithium-ion Battery Bagus Anggraini1,2*, Evvy Kartini 2,3, Abdulloh Rifai3 , Muhammad Fakhruddin 2,3, Nawwal Hikmah 4, Akhmad Saufan1 , Imam Basori1 1Departement of Mechanical Engineering, Engineering Faculty, Universitas Negeri Jakarta, Jl. R.Mangun Muka Raya, Pulo Gadung, East Jakarta, Jakarta 13220, Indonesia 2National Battery Research Institute (NBRI), Indonesian Life Science Center, Technology Business Zone BRIN Puspitek Area, Bogor 16340, West Java, Indonesia 3Nano Material Research Organization, National Research and Innovation Agency (BRIN), KST. B.J. Habibie, Puspitek, Setu, South Tangerang 15314, Indonesia 4Department of Chemistry, Universitas Lambung Mangkurat, Banjarbaru, Indonesia Abstract Lithium Nickel Manganese Cobalt Oxide (NMC) cathode materials are promising for lithium-ion batteries because of their balanced capacity, structural stability, and cost-performance characteristics. This study synthesized LiNi&#8320-.&#8326-Mn&#8320-.&#8323-Co&#8320-.&#8321-O&#8322- (NMC 631) cathode materials using technical-grade and analytical-grade materials through the carbonate co-precipitation method. The work aims to evaluate the influence of material grade on the morphological, structural, compositional, and performance properties of NMC 631 cathode materials. The samples were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and galvanostatic charge-discharge (GCD) testing. SEM results showed that NMC 631-A had a smaller average particle size of 134.11 nm than NMC 631-T at 243.61 nm, indicating a shorter lithium-ion diffusion pathway. EDS analysis confirmed that both samples approached the designed Ni:Mn:Co ratio of 6:3:1. XRD results showed layered hexagonal structures with c/a values above 4.8999, while NMC 631-A exhibited a higher I(003)/I(104) ratio of 1.198 than NMC 631-T at 1.10, indicating lower cation mixing. GCD testing confirmed that NMC 631-A delivered higher specific discharge capacity and better rate capability. Nevertheless, NMC 631-T showed acceptable cycling stability, indicating its potential as a cost-effective alternative for scalable NMC 631 cathode material production. Keywords: NMC631, cathode material, technical-grade material, analytical-grade material, lithium-ion battery. Share Link | Plain Format | Corresponding Author (Bagus Anggraini)

133	Material Physics	ABS-170
Power Factor Performance of MnF3 Monolayer Under Hubbard Correction teguh budi prayitno Universitas Negeri Jakarta Abstract The collinear density functional theory was used to obtain the electronic structure of MnF3 monolayer. We observed the Dirac half metallic properties from the band structures. The extracted data was used to compute the Seebeck coefficient and electrical conductivity, which were then used to calculate the power factor. As the Hubbard correction was applied, the band gap increases. The increase of band gap influenced the peak of power factor. To improve the performance, we used doping to shift the Fermi level in the power factor. This implied that Hubbard correction controlled the electronic structure, which affected the power factor. Keywords: MnF3, Hubbard correction, Power factor Share Link | Plain Format | Corresponding Author (Teguh Budi Prayitno)

134	Material Physics	ABS-171
Influence of Hubbard Term on Power Factor in Zigzag Graphene Nanoribbon Teguh Budi Prayitno Universitas Negeri Jakarta Abstract We examined the power factor in zigzag graphene nanoribbon under the Hubbard term as a function of chemical potential. The computational approach was used through the density function theory and Boltzmann transport. As the value of Hubbard term increases, the band gap increases, thus affected the Seebeck coefficient and electrical conductivity. We then calculated the power factor through those two quantities. We found that doping should be included to improve the performance of power factor. This indicated that Hubbard term and doping are two important factors to improve the power factor. Keywords: Zigzag graphene nanoribbon, Hubbard correction, Power factor Share Link | Plain Format | Corresponding Author (Teguh Budi Prayitno)

135	Material Physics	ABS-175
Critical Parameters in Hydrothermal Synthesis of M-Type Barium Hexaferrite : Phase Evolution, Sintering Effect, and Comparison with Conventional Synthesis Routes Muhammad Iqbal(1), Azwar Manaf(1*), Januar Widakdo(1**), Mas Ayu Elita Hafizah(2), Nur Ika Puji Ayu(1) 1. Department of Physics, Universitas Indonesia, Beji, Depok 16424, Indonesia 2. Universitas Pertahanan, Citeureup, Bogor 16810, Indonesia *azwar[at]ui.ac.id **januar.widakdo[at]ui.ac.id Abstract M-type barium hexaferrite (BaFe12O19) is one of the most widely studied ferrimagnetic materials due to its high magnetocrystalline anisotropy, excellent chemical stability, high curie temperature, and promising magnetic properties for permanent magnets, microwave absorbers, and electromagnetic devices. In this study, BaFe12O19 was synthesized using a modified hydrothermal method and crystallite size was systematically investigated. The synthesis was carried out using Ba(NO3)2 and Fe(NO3)3.9H2O precursors under hydrothermal conditions at 220 deg C for 24 h in a highly alkaline medium prepared using carbonate-free NaOH solution. Two synthesis routes were compared, namely hydrothermal synthesis without sintering and hydrothermal synthesis followed by sintering treatment. Phase identification was conducted using X-ray diffraction (XRD), while crystallite size was estimated using the Debye-Scherrer equation. The XRD results revealed that the sintered sample predominantly consisted of M-type BaFe12O19 with minor hematite (alpha-Fe2O3) phase, whereas the non-sintered sample was dominated by hematite with minor BaFe2O4 phase, indicating incomplete phase transformation during hydrothermal processing alone. The crystallite size of the sintered sample was found to range between 15-45 nm, while the non sintered sample exhibited larger crystallite sizes ranging from 32-78 nm. The findings confirm that post-sintering treatment plays a crucial role in promoting the complete transformation of intermediate phases into thermodynamically stable BaFe12O19. Furthermore, this study highlights several critical factors in hydrothermal synthesis, including Fe/Ba ratio, alkaline concentration, and thermal treatment, which strongly influence phase purity and crystal growth behavior of BaFe12O19. Keywords: Barium hexaferrite, hydrothermal synthesis, sintering, phase evolution, hematite, BaFe2O4 Share Link | Plain Format | Corresponding Author (Muhammad Iqbal)

136	Material Physics	ABS-178
Effect of Glycerol Concentration on the Photoelectrochemical Water Splitting Perfomance of BiVO4 Photoanode in NaNO3 and KNO3 Electrolyte Fita Widiyatun(a*), Muhammad Taqian Mutahari(a), Ferry Anggoro Ardy Nugroho (a), and Vivi Fauzia (a) a)Department of physics, Universitas Indonesia, Depok 16424, Indonesia Abstract Glycerol as a biomass-derived byproduct has attracted considerable attention in photoelectrochemical processes due to its ability to enhance charge separation efficiency and photocurrent density. In this study, the effect of glycerol concentration in sodium nitrate (NaNO3) and potassium nitrate (KNO3) electrolyte solutions at pH 2 was investigated using a bismuth vanadate (BiVO4) photoanode. The influence of glycerol concentration and electrolyte type on the photoelectrochemical performance was evaluated through several characterization techniques, including linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) measurements. The results of this study are expected to provide insight into the effect of glycerol concentration and electrolyte cations in improving the performance of BiVO4 photoanodes in photoelectrochemical systems. Keywords: photoelectrochemical water splitting- glycerol- BiVO4 Share Link | Plain Format | Corresponding Author (Fita Widiyatun)

137	Material Physics	ABS-184
3D Printed of Polylactic Acid/Silver Nanoparticles Electroactive Scaffolds Using Low Budget Commercial 3D Printer Helmi Majid Ar Rasyid, Fitriyatul Qulub, Fathan Aditya Sanjaya, Akfiny Hasdi Aimon, Anggraini Barlian and Arie Wibowo 1 Magister Nanotechnology, Graduate School, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia 2 Materials Science and Engineering Research Group, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 Indonesia 3 Department of Physics, Faculty of Mathematical and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, 40132, Bandung, Indonesia 4 School of Life Science & Technology, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia 5 Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia Abstract Keywords: electroactive scaffold, low budget commercial 3D printer, polylactic acid, silver nanoparticles Share Link | Plain Format | Corresponding Author (Arie Wibowo)

138	Material Physics	ABS-188
Microstructure, Hardness, and Corrosion Resistant Characteristics of Cu-28Zn-1Sn Alloy Under Cold Rolling and Annealing Treatments Imam Basori, Dimas Hadi Prahasto, Ferry Budhi Susetyo Department of Mechanical Engineering, Universitas Negeri Jakarta, Indonesia Abstract This study aims to investigate the effects of cold rolling and annealing processes on the microstructure, hardness, and corrosion resistance of Cu-28Zn-1Sn brass alloy. The brass specimens were subjected to cold rolling with thickness reductions of 20, 40, and 70 percent, followed by annealing treatments at temperatures of 300 C, 400 C, 500 C, and 600 C for 30 minutes. Microstructural analysis was conducted using optical microscopy, hardness was evaluated using the Vickers hardness method, and corrosion resistance was assessed through a weight loss test in an H&#8322-SO&#8324- corrosive medium. The results indicate that cold rolling increased the hardness of the alloy due to strain hardening, which was accompanied by improved corrosion resistance. The hardness values increased with increasing plastic deformation during cold rolling, reaching 185.4 VHN, 247.2 VHN, and 254.8 VHN for 20, 40, and 70 percent reductions, respectively. Corrosion resistance also improved with increasing deformation, as indicated by the reduction in corrosion rate from 0.119 mmpy at 20 percent reduction to 0.112 mmpy at 40 percent reduction and 0.077 mmpy at 70 percent reduction. In contrast, the annealing treatment significantly reduced hardness at all deformation levels, particularly at 70 percent deformation, where the hardness decreased from 243.3 VHN at 300 C to 89.9 VHN at 600 C. Annealing also reduced the corrosion rate, with the lowest corrosion rate observed at 600 C annealing and the highest at 300 C for all deformation levels. The annealing process was proven to restore corrosion resistance and improve the microstructure through recrystallization mechanisms. Keywords: Cu-28Zn-1Sn- Cold rolling- Annealing- Hardness- Corrosion resistance Share Link | Plain Format | Corresponding Author (IMAM BASORI)

139	Material Physics	ABS-192
Calcined Black Soldier Fly Shells as a Sustainable Bio-Derived Coagulant for Efficient Removal of Cd, Cu, Pb, and Fe from Aqueous Systems Wahyu Setiawan (a), Siska Nuri Fadilah (a), Subriyer Nasir (b), Muhammad Said (b), Diah Kartika Sari (c), Fakhili Gulo (a,c*) a) Department of Environmental Science, Postgraduate Program, Universitas Sriwijaya, Palembang 30139, South Sumatera, Indonesia *fgulo[at]unsri.ac.id b) Department of Chemical Engineering, Faculty of Engineering, Universitas Sriwijaya, Palembang, 30139, South Sumatera, Indonesia c) Department of Chemistry Education, Universitas Sriwijaya, Inderalaya, Ogan Ilir 30862, Indonesia Abstract Heavy metal pollution in water is a significant environmental challenge and requires efficient, sustainable treatment technologies. Black Soldier Fly (BSF) is known to have a high carbonate mineral content, making it a potential bio-derived coagulant. This study evaluated the performance of calcined Black Soldier Fly shells (CBSFS) as a biomass-based biocoagulant for the removal of Cd, Cu, Pb, and Fe from solution. The experiment was conducted in batches with varying contact times (5-120 minutes) and initial concentrations (10 until 100 mg/L) at 28 celcius, natural pH, and stirring at 160 rpm. Metal concentrations were analysed using Atomic Absorption Spectroscopy (AAS). The results showed that CBSFS performance increased significantly over time, with efficiencies reaching 99.46% (Pb), 99.04% (Cd), 98.43% (Cu), and 96.90% (Fe) within 30 minutes and remaining high (>96%) for up to 120 minutes. At various concentrations, the removal efficiency ranged from 92.31 to 99.02%, indicating stable performance against changes in metal load. This removal pattern indicated the dominance of the coagulation-precipitation mechanism involving floc formation and separation through sedimentation. Overall, CBSFS demonstrated effective, stable performance and high potential as a biocoagulant for low-cost, efficient, and environmentally friendly heavy metal-contaminated water treatment applications that support a circular economy. Keywords: Biocoagulant, CaCO3, Hermetia illucens, Heavy metals removal, Water treatment Share Link | Plain Format | Corresponding Author (Wahyu Setiawan)

140	Material Physics	ABS-198
Surface versus Bulk Ni-Cu Doping in TiO&#8322- Nanoparticles: Visible-Light Absorption Enhancement for Photocatalytic Water Splitting Mulda Muldarisnur (a*), Noni Novianti (a), Darma Septian (a), Diana Vanda Wellia (b), and Yetria Rilda (b) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Andalas, Padang, Indonesia *muldarisnur[at]sci.unand.ac.id b) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Andalas, Padang, Indonesia Abstract TiO&#8322- has been widely studied as a photocatalyst for hydrogen production through water splitting. Its large band gap, however, limits absorption mainly to the ultraviolet region, which is only a very small fraction of sunlight. This work reports optical simulation of visible-light absorption enhancement in surface- and bulk-doped Ni-Cu TiO&#8322- nanoparticles. TiO&#8322- nanoparticles were assumed to be 20-50 nm in diameter, while Ni and Cu dopants having diameters of 1-5 nm were homogeneously distributed either inside the TiO&#8322- bulk or on the particle surface. The total metal fraction was varied below 5% to represent low dopant loading. The optical absorption, scattering, and extinction cross sections were calculated using Mie theory. The optical properties of surface-doped TiO&#8322- nanoparticles were investigated using the effective refractive index models. The visible-light absorption of Ni-Cu doped TiO&#8322- was compared with pure, Ni-doped, and Cu-doped TiO&#8322- nanoparticles. The Ni-Cu co-doping was found to enhance visible-light absorption more effectively than the pure and single-metal doping. The modified dielectric response and stronger light-matter interaction at the metal-TiO&#8322- interface result in improvement of absorption. Surface-doped Ni-Cu TiO&#8322- shows stronger absorption enhancement than bulk-doped TiO&#8322- because the metal domains interact more directly with incident light. The enhancement of visible light absorption strongly depends on diameter and filling fraction of metal doping. These findings provide a simulation-based guideline for designing Ni-Cu doped TiO&#8322- nanoparticles with improved visible-light activity for photocatalytic hydrogen production. Keywords: Ni-Cu doped TiO&#8322-- visible-light absorption- Mie theory- effective refractive index- photocatalytic water splitting. Share Link | Plain Format | Corresponding Author (Mulda Muldarisnur)

141	Material Physics	ABS-211
Control of PVA Nanofiber Alignment via Variation of Collector Plate Distance in the Electrospinning Process Anjar Taufik Hidayat1, Nur Afifah Zen2, Yulian Zetta Maulana2, Ahmad Kusumaatmaja3 1. Department of Physics, Universitas Indonesia. *anjar.taufik[at]ui.ac.id 2. Department of Telecommunication Engineering, Universitas Telkom. 3. Department of Physics, Universitas Gadjah Mada. Abstract Poly(vinyl alcohol) (PVA) nanofibers were successfully fabricated using the electrospinning technique to investigate the effect of collector configuration on fiber alignment. A 15 wt.% PVA solution in distilled water was electrospun at an applied voltage of 15 kV for 3 minutes, with a tip-to-collector distance of 12 cm. SEM image analysis showed that the resulting nanofibers had an average diameter of 433 nm. To control fiber orientation, a collector consisting of two parallel copper plates (each 10 cm in length) was used, with the inter-plate distance varied from 2 to 7 cm. The degree of nanofiber alignment was analyzed using ImageJ and quantified by the nematic order parameter. The results indicate that fiber alignment decreases with increasing inter-plate distance, with nematic order parameter values of 0.96, 0.91, 0.90, 0.90, 0.86, and 0.83 for samples with plate distances of 2, 3, 4, 5, 6, and 7 cm, respectively. These findings demonstrate that highly aligned nanofibers can be fabricated by employing relatively small inter-plate distances in the collector configuration. Keywords: Electrospinning, Poly(vinyl alcohol), Nanofiber alignment, Parallel collector plate Share Link | Plain Format | Corresponding Author (Anjar Taufik Hidayat)

142	Material Physics	ABS-212
Batch Adsorption and Kinetic Study of Cd(II) Removal Using Hermetia illucens Shell-Based Biosorbent Wahyu Setiawan (a), Siska Nuri Fadilah (a), Subriyer Nasir (b), Muhammad Said (b), Zainal Fanani (c), Fakhili Gulo (a*) a) Department of Environmental Science, Postgraduate Program, Universitas Sriwijaya, Palembang 30139, South Sumatera, Indonesia b) Department of Chemical Engineering, Faculty of Engineering, Universitas Sriwijaya, Palembang, 30139, South Sumatera, Indonesia c) Department of Chemistry, Universitas Sriwijaya, Indralaya, Ogan Ilir 30662, South Sumatra, Indonesia Abstract Hermetia illucens shell was utilized as an environmentally friendly biosorbent for the adsorption of Cd heavy metal ions from aqueous solution. Surface morphology characterization using SEM at 1000X magnification revealed a rough, heterogeneous, and porous structure, indicating the presence of potential active sites for adsorption. Batch adsorption experiments were conducted and the adsorption kinetics were evaluated using pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich models. The results showed an experimental adsorption capacity of 17.11 mg/g with a maximum removal efficiency of 20.07 percent. The PFO model yielded a Qe value of 13.94 mg/g and a K1 value of 0.47 min^-1 with an R^2 of 0.8683, while the Elovich model produced A and B constants of 18.45 and 0.30, respectively, with an R^2 of 0.88407. The PSO model exhibited the best fit with a Qe value of 17.11 mg/g, a K2 value of 0.02 g mg^-1 min^-1, and the highest R^2 value of 0.97481, suggesting that the adsorption process was predominantly governed by chemisorption mechanisms. These findings demonstrate that Hermetia illucens shell has strong potential as a low-cost, sustainable, and eco-friendly biosorbent for Cd-contaminated wastewater remediation. Keywords: Heavy metal- black soldier fly- adsorption- Sustainable wastewater treatment Share Link | Plain Format | Corresponding Author (Wahyu Setiawan)

143	Material Physics	ABS-214
Effect Ageing Time on Structure and Surface Area of Zeolite Synthetic from Low Grade Bauxite and Rice Husk Ash Arif Rahman (a), Setia Budi (a), Y. Eko Adi Prasetyanto (b), Anwar Usman (c), Nur Kusumaningrum (a). (a) Department of Chemistry, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Rawamangun, East Jakarta, Indonesia, (b) Department of Pharmacy, School of Medicine and Health Sciences, Atma Jaya Catholic University of Indonesia, Jalan Pluit Utara no 2, Jakarta Utara, 14440, Indonesia (c) Department of Chemistry, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410, Brunei Darussalam Abstract This study investigates the effect of ageing time on the structural evolution and surface area characteristics of synthetic zeolite prepared from low-grade bauxite as an alumina source and rice husk ash as a silica precursor. The utilization of low-quality mineral resources and agricultural waste offers a sustainable alternative for the synthesis of high-value zeolitic materials. Zeolite synthesis was carried out through an alkali fusion process followed by ageing and hydrothermal crystallization. Variations in ageing time were applied to evaluate their influence on phase transformation, crystallinity, morphology, and specific surface area of the synthesized products. Structural characterization using Fourier Transform Infrared (FTIR) spectroscopy indicated gradual changes in the Si-O-Al and Si-O vibrational bands associated with the evolution of aluminosilicate frameworks during the ageing process. X-ray diffraction (XRD) analysis demonstrated that prolonged ageing promoted the formation of more stable precursor phases prior to hydrothermal treatment. However, excessive ageing reduced the conversion efficiency toward Zeolite NaX formation, resulting in lower crystallinity of the Faujasite (FAU) framework. Surface area analysis based on the Brunauer-Emmett-Teller (BET) method revealed that longer ageing times caused a significant decrease in specific surface area, indicating reduced pore development and limited zeolitization. This behavior is attributed to the stabilization of precursor species that inhibited further transformation into highly porous zeolitic structures. Scanning electron microscopy (SEM) observations further confirmed the morphological evolution of the synthesized materials with increasing ageing duration. The results demonstrate that ageing time plays a critical role in controlling precursor stability, zeolite crystallization, and surface properties, thereby determining the quality of Zeolite NaX synthesized from low-grade bauxite and rice husk. Keywords: Aging time, Low grade bauxite, Zeolite X, Rice Husk ash Share Link | Plain Format | Corresponding Author (Arif Rahman)

144	Material Physics	ABS-215
Magnetic Properties of YIG/LaFeO&#8323- Composites for Electromagnetic Wave Absorption Marzuki Naibaho, Ameer Noor Affan, Nova Maharani, Masno Ginting, and Januar Widakdo 1 Department of Physics, Universitas Indonesia, Depok 16424, Indonesia 2 Research Center for Energy Materials (PRME) - National Research and Innovation Agency (BRIN), Complex Puspiptek Building 440-441, Tangerang-South, Banten, Indonesia 15314. Abstract Yttrium iron garnet (YIG)/LaFeO&#8323- composites are considered promising candidates for electromagnetic wave absorbing materials due to their excellent magnetic properties and dielectric behavior. In this study, YIG/LaFeO&#8323- composites were synthesized and characterized to evaluate their magnetic properties and electromagnetic wave absorption performance. Magnetic characterization was carried out using a Vibrating Sample Magnetometer (VSM) to determine the saturation magnetization, remanence, and coercivity values. The results indicate that the composites exhibit ferromagnetic behavior, which contributes to magnetic loss mechanisms during electromagnetic wave absorption. Furthermore, the electromagnetic wave absorption properties were investigated using a Vector Network Analyzer (VNA) over a specific frequency range. The measurements revealed that the YIG/LaFeO&#8323- composites achieved good reflection loss performance due to the synergistic effect of magnetic loss and impedance matching. These findings demonstrate that YIG/LaFeO&#8323- composites have strong potential for application as electromagnetic wave absorber materials in modern electronic and telecommunication devices. Keywords: YIG/LaFeO3, Magnetic properties, Microwave absorbtion properties Share Link | Plain Format | Corresponding Author (Marzuki Naibaho)

145	Material Physics	ABS-216
Synthesis of Zeolite A from Bangka Kaolin as a high-performance host for fluorescent compounds Arif Rahman (a), Hanhan Dianhar (a), Agung Purwanto (a), Annisaa Endah Wijianti (a), Eny Kusrini (b), Y. Eko Adi Prasetyanto (c), Anwar Usman (d) (a) Department of Chemistry, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Rawamangun, East Jakarta, Indonesia (b)Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424, Indonesia (c) Department of Pharmacy, School of Medicine and Health Sciences, Atma Jaya Catholic University of Indonesia, Jalan Pluit Utara no 2, Jakarta Utara, 14440, Indonesia (d) Department of Chemistry, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410, Brunei Darussalam Abstract This study reports the synthesis of Zeolite A derived from Bangka kaolin and its potential application as a high-performance host material for luminescent compounds. The increasing demand for stable and efficient luminescent materials has encouraged the development of inorganic host matrices possessing high structural uniformity, thermal stability, and controlled porosity. In this work, Bangka kaolin was utilized as a low-cost and abundant aluminosilicate precursor for the preparation of Zeolite A through alkali activation followed by hydrothermal crystallization. The synthesized material was characterized to evaluate its crystal structure, phase purity, morphology, and textural properties relevant to luminescent applications. X-ray diffraction analysis confirmed the successful formation of highly crystalline Zeolite A with a well-defined cubic framework structure. Fourier Transform Infrared spectroscopy indicated the formation of characteristic aluminosilicate vibrations associated with the zeolitic framework, while scanning electron microscopy revealed uniform cubic crystal morphology with homogeneous particle distribution. The high structural regularity and ordered pore system of Zeolite A provide an effective microenvironment for the dispersion and stabilization of luminescent species, minimizing aggregation and improving optical performance. In addition, the framework stability and ion-exchange capability of Zeolite A make it a promising host matrix for incorporating luminescent ions or molecules. The results demonstrate that Bangka kaolin is a suitable raw material for the sustainable synthesis of high-quality Zeolite A and highlight the important role of structural uniformity in enhancing the performance of zeolite-based luminescent materials. Keywords: Zeolite A, Kaolin, Host, Fluorescence Share Link | Plain Format | Corresponding Author (Arif Rahman)

146	Material Physics	ABS-244
Experimental study of fire spreading CFRP based on the addition of rice husk ash silica for an Automotive Component Himawan Hadi Sutrisno (a*), Catur Setyawan Kusumohadi (a), Mohamed Thariq Hameed Sultan (b), Layla Najwa Husaini (a), and Anissa Intan Audrya (a) a) Fire Safety Engineering, Faculty of Engineering, Universitas Negeri Jakarta, Jakarta, Indonesia *Himawan-hadi[at]unj.ac.id b) Department of Aerospace Engineering, Faculty og Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Abstract Carbon fiber-reinforced polymer (CFRP) is the material of choice in various fields of the manufacturing industry, especially in the aircraft industry, as a body component. However, the automotive industry also makes extensive use of this material because it is lighter than other materials. To enhance CPRP^s safety, the fire-propagation resistance of this material was improved in this study. Using experimental methods, the effect of adding RHA silica on CFRP fire resistance was evaluated across 5 variations in the volume composition of the thermoset matrix: no additional RHA silica, 5%, 10%, 20% and 30%. The CFRP production process uses the Hand Lay Up method. Using a fire rate equipment test, the largest Rice Husk Ash (RHA) silica composition in CFRP provides a significant fire spreading effect compared to other compositions. In addition to the fire spread test, the mass loss rate (MLR) was also evaluated. Therefore, incorporating silica from rice husk ash (RHA) into Carbon Fiber Reinforced Polymer (CFRP) composites shows significant potential for automotive applications, particularly in parts exposed to elevated temperatures or near engine heat sources. The improved flame resistance, delayed ignition time, and reduced burning rate achieved by adding RHA silica can enhance the safety and reliability of these components under service conditions. Keywords: CFRP- Silica- Fire Spreading- Fire Resistance Share Link | Plain Format | Corresponding Author (Himawan Hadi Sutrisno)

147	Medical Physics and Biophysics	ABS-6
Investigation of the Imaging Dose of Various Generation of CBCT Linear Accelerators Sample Abstract Veni Setyowati1,2, Rory Agustria2, Sri Bintang Arofah2, Syarifatul Ulya2, Supriyanto Ardjo Pawiro1,2 1Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, West Java 2Department of Radiation Oncology, Dharmais Cancer Hospital, Jakarta Abstract Integration of Cone-Beam Computed Tomography (CBCT) into Linear Accelerators (LINAC) has been developed as a tool for verifying patient positioning in radiotherapy but may increase the lifetime attributable risk (LAR) of cancer and damage to healthy organs. This study aimed to evaluate and compare the CBCT imaging dose from four LINACs across different generations (Elekta Synergy versus Versa HD and Varian Trilogy versus TrueBeam) during radiotherapy. At Dharmais Cancer Hospital, forty five thermoluminescent dosimeter (TLD) chips were calibrated using a Terasix X-ray simulator and measured with a Raysafe multimeter. TLDs are employed and attached to the surface of an Alderson RANDO phantom in three areas: Pelvis (12 points), Thorax (15 points), and Head (18 points). Each LINAC is operated using clinical CBCT parameters. TLD readings in nC were converted to dose (mGy) by multiplying with a calibration factor, then analyzed based on organ localization through TLD points placed on the phantoms anterior, right lateral, and left lateral sides. In the pelvis, the highest dose was observed with Versa HD 2.94mGy (SD=0.30), whereas the lowest was observed by Trilogy 0.84mGy (SD=0.10). In the thorax, Trilogy yielded the highest dose 1.72mGy (SD=0.40) while TrueBeam yielded the lowest 0.75 mGy (SD=0.06). The highest difference between CBCT was observed with Trilogy and TrueBeam is 0.97mGy. The highest dose in the head was in Trilogy 1.23mGy (SD=0.49), and the lowest dose was in Versa HD 0.47 mGy (SD=0.10). Variation in imaging dose among LINAC generations does not always indicate that the newer generations deliver lower doses. Trilogy delivered a dose in the thorax 0.97 mGy higher than TrueBeam . However, in the pelvis, Versa HD was delivered a dose 0.85mGy higher than Synergy and even 2.10mGy higher than Trilogy. This indicates that imaging protocols and machine configurations influence differences in CBCT dose more than CBCT Linac generation. Keywords: Imaging Dose, CBCT, Linac Generation, TLD Share Link | Plain Format | Corresponding Author (Veni Setyowati)

148	Medical Physics and Biophysics	ABS-14
Exploration of Curcumin and HER2 ICD Interaction Processes Using Unguided Molecular Dynamics Simulation, Coarse-Grained Modelling, and Free Energy Analysis Retno Dewi Purnawati* and Acep Purqon Physics Study Program, Institut Teknologi Bandung Abstract HER2 (ERBB2) overexpression occurs in approximately 20-30% of breast cancer cases and correlates with disease aggressiveness and poor prognosis. Although antibody-based therapies and tyrosine kinase inhibitors have been developed, the presence of side effects and therapeutic resistance encourages the search for safer alternatives, including natural compounds like curcumin. However, the structural and energetic understanding of the interaction between curcumin and HER2, particularly at the intracellular domain, remains limited. This study investigates the interaction between curcumin and the HER2 intracellular domain (ICD) using molecular dynamics (MD) simulations with coarse-grained (CG) modelling and the Martini 2.2 force field. The HER2 ICD structure (PDB: 3RCD) was reconstructed and solvated in a box containing water and 0.15 M NaCl. Four models were constructed by integrating curcumin at four different initial positions. Each model was simulated in triplicate for 1 microsecond each, resulting in a total simulation time of 12 microseconds. The simulation results indicate that curcumin does not bind to a single specific site but instead dynamically explores the protein surface. Free energy calculations using the free energy perturbation (FEP) method with a flat-bottom potential were performed to evaluate the thermodynamic profile of the interaction. This study demonstrates that the combination of CG-MD and FEP is an efficient approach for exploring protein-ligand interactions and provides new insights into the potential of curcumin as a modulator of HER2 function. Keywords: HER2 (ERBB2)- Curcumin- Coarse-grained molecular dynamics- Free energy perturbation Share Link | Plain Format | Corresponding Author (Retno Dewi Purnawati)

149	Medical Physics and Biophysics	ABS-19
Characterization of Occupational Radiation Exposure in Interventional Radiology Based on TLD Measurements Rini Anggraeni1, 2,a), Widya Apriyani S3, Lukmanda Evan Lubis1, Syahril Siregar1,b) 1Department of Physics, Faculty Mathematics and Natural Sciences, Universitas Indonesia, 16424, Depok, Jawa Barat, Indonesia 2National Research and Innovation Agency (BRIN),10340, Jakarta, Indonesia 3Radiology Department, Dharmais National Cancer Hospital, 11420, Jakarta Indonesia Abstract Interventional radiology has rapidly developed due to its advantages in diagnostic imaging and minimally invasive procedures. However, radiation exposure during these procedures remains a significant concern for healthcare workers. This study aims to evaluate the distribution of occupational radiation dose among healthcare workers during interventional radiology procedures, specifically transarterial chemoembolization (TACE), through direct measurements. Dose measurements were performed using thermoluminescent dosimeter (TLD) rods under simulated clinical TACE conditions. TLDs were placed at positions representing the radiologist, Nurse 1, Nurse 2, and radiographer, at different heights to assess both eye lens and whole-body doses. The results indicate that radiation dose varies depending on staff position, height, and irradiation mode, with higher doses observed during cine mode. Nevertheless, all measured doses remained below the limits recommended by the International Commission on Radiological Protection (ICRP). These findings highlight the importance of optimizing imaging techniques and the effective use of radiation protection devices to minimize occupational exposure. Keywords: interventional radiology, occupational dose, TLD, healthcare worker, radiation protection Share Link | Plain Format | Corresponding Author (Rini Anggraeni)

150	Medical Physics and Biophysics	ABS-20
Comparative Evaluation of Solid-State and Ionization Chamber Detectors for Dose Metric Accuracy in Fluoroscopy Dandi Hambali (a,b*), Dwy Hervin (c), Lukmanda Evan Lubis (b), Djarwani S. Soejoko (b) a) Jakarta Medical Devices and Facilities Safety Center, Jl. Percetakan Negara No.23A, Jakarta 10570, Indonesia b) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia *dandi.hambali31[at]ui.ac.id c) Fatmawati Hospital, Jl. RS. Fatmawati Raya, Jakarta 12430, Indonesia Abstract An angiography system is an interventional fluoroscopy modality characterized by complex radiation exposure and the potential for high radiation doses due to prolonged procedure durations. Therefore, consistent and accurate dose monitoring using an integrated kerma-area product (KAP) meter is required. However, this KAP meter must be verified and calibrated using reliable reference instruments. This study aims to investigate the characteristics of X-ray multimeters (XMMs) using a standard ionization chamber as a reference in air kerma rate measurements and to evaluate the reliability of XMMs as reference instrument for KAP meters verification. An experimental study was performed using eight XMMs under clinical fluoroscopy interventional conditions. Air kerma rate measurements were performed across RQA 4 - 7, while KAP meter verification was conducted under Clinical Fluoroscopy and Cine modes at 60 - 90 kV. Data were analysed using mean values and standard deviation. The correction value is also used to compare the measured value with the reference value. The results showed that XMM correction factors for air kerma rate range of 1 - 12%, decreasing at higher energies. In KAP meter verification, correction factors reached up to 18% in Cine Mode and 13% in Fluoroscopy Mode, indicating differences in measurement characteristics between modes. These results indicate that XMM response depends on beam energy and quality- therefore, the application of specific correction factors is required to ensure accurate and reliable dose measurements. Keywords: Fluoroscopy, KAP meter, X-ray multimeters (XMM), Air kerma rate, Correction factor Share Link | Plain Format | Corresponding Author (Dandi Hambali)

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