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31	Energy and Environmental Physics	ABS-10
Forward Modeling Of Electromagnetic Induction Based On Finite Difference Frequency Domain Methods Using Variations Of Electrical Conductivity In Agricultural Area Ima Rahmadanti and Harry Mahardika Fakultas Matematika dan Ilmu Pengetahuan Alam Institut Teknologi Bandung Abstract This study aims to model secondary magnetic field data from the distribution of electrical conductivity values from actual agricultural field measurements. This is achieved by solving the frequency domain (Helmholtz) diffusive wave equation for magnetic field component using the Finite Difference Frequency Domain (FDFD) method. The modeling begins with the derivation of Maxwell^s equation in the frequency domain to obtain the diffusive wave equation that will be used. The processing carried out in the modeling cannot be separated from the boundary conditions to find a solution to the wave equation. The explanation of the field measurements that have been carried out makes the modeling focused on solving the wave equation for the magnetic field. Therefore, this study will produce magnetic field value data, where in actual field operation the data is directly processed into electrical conductivity data. The resulting magnetic field value is considered as the primary magnetic field which is then used to determine the secondary magnetic field. Keywords: Electrical Conductivity, Electromagnetic Methods, FDFD, Numerical Modeling. Share Link | Plain Format | Corresponding Author (Harry Mahardika)

32	Energy and Environmental Physics	ABS-41
Compressive Property of Biomass Briquettes Made of Hazelnut Shell Waste and Peanut Shell Yessi Gusnia1), Irfan Dwi Aditya2,a), and Widayani1) 1 Nuclear Physics and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha no. 10 Bandung 40132, Indonesia. 2 Instrumentation and Computational Physics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung 40132, Indonesia Abstract In Indonesia, energy consumption increases as with its population, while fossil energy sources keep running out. This condition forces the development of non-fossil energy source. One promising alternative is biomass briquette. In this study a biomass briquette was made using hazelnut shell waste (limbah cangkang kemiri CK) and peanut shell (kulit kacang tanah KT) with various CK concentrations: 0/24, 4/24, 8/24, 12/24, 16/24, 20/24, and 24/24 (w/w). Initially, dried CK and KT waste were processed into charcoal powder with a particle size of ~ 0,25 mm. The briquette was prepared by densification of the two charcoal mixtures at a pressure of 29778,99 N/m2 for 15 min, followed by heating at 60 &#8451- for 4 h. Due to storage and delivery process in the application, briquettes must have good compressive properties. In this study, compressive property of the produced briquette was characterized using a universal testing machine (UTM). The results showed that the values of ultimate strength, modulus of elasticity, and strain at fracture of the CK-KT briquette increased with increasing CK concentration, with highest values of 5.69 MPa, 80 MPa and 0.146, respectively. Keywords: energy- briquette- compression- hazelnut shell waste- peanut shell Share Link | Plain Format | Corresponding Author (Yessi Gusnia)

33	Energy and Environmental Physics	ABS-70
Time Lapse Measurement of Reservoir^s Parameters Change due to CO2 Injection in Parigi Carbonate West Java Bagus Endar B. Nurhandoko1,*, Satryo Wibowo2, Rufidi Chandra3, Boma Apriansyah3, Zerlinda Hendietri3, Ratih Pratiwi1, Maria Cindrawati1, Tri Agatha Manulang1, Susilowati2, Fathur Rizal Abdillah2, Nefrizal4,Amelia Nurani4, Aris Endaryanto4, Eko Bambang Supriyanto2 1) Physics Department, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology 2) Rock Fluid Imaging Lab 3) Indocement Tunggal Prakasa Tbk 4) Elnusa Tbk *)Email: bagus[at]itb.ac.id Abstract CO2 injection is a process that involves injecting carbon dioxide gas into various substances or environments for different purposes. This technique, also known as carbon capture and storage (CCS) or carbon capture, utilization, and storage (CCUS), aims to prevent or reduce carbon dioxide emissions from reaching the atmosphere, where they would contribute to global warming and climate change. CCUS can also use the captured carbon dioxide for various purposes, such as enhancing oil recovery, producing fuels, chemicals, or building materials, or storing it underground or underwater. In this study, we investigated the phenomena of CO2 injection in Parigi carbonate rock from West Java. Our study involved various laboratory measurements of Parigi carbonate rock, focusing on changes in porosity due to CO2 injection. The porosity changes were observed using micro images analysis from microscope time-lapse analysis, CT-scan, and laboratory helium porosity meter. The laboratory measurements of CO2 injection in brine water showed that the pH of the water can decrease to below 5, creating an acidic environment that induces dissolution of the pore structure. We measure the effect of CO2 injection to the Parigi carbonate samples by time lapse measurement strategy. Results of the laboratory measurements showed that the porosity increased during CO2 injection and the mass of the samples decreased during the CO2 injection process. These phenomena suggest that CO2 may induce dissolution of carbonate rock. Furthermore, the changes in porosity confirm that there is a chemical reaction during CO2 injection processes in Parigi carbonate. Keywords: CO2 injection, Parigi carbonate, CCUS, porosity change, chemical reaction of pore Share Link | Plain Format | Corresponding Author (Bagus Endar B. Nurhandoko)

34	Energy and Environmental Physics	ABS-91
The Influence of Catalyst Concentration on Methylene Blue Photodegradation using Magnetically Reusable CoFe2O4/TiO2 Nanocomposites Synthesized via Green Route Utilizing Moringa Oleifera Yumna Haura Zahra (a), Dianiwati (a), Citra Dwi Lestari (a), Rizal Ahmad Fauzi (a), Nurul Imani Istiqomah (b), Deska Lismawenning Puspitarum (b)(c), Edi Suharyadi (b), Hasniah Aliah (a*) (a) Department of Physics, Faculty of Science and Technology, UIN Sunan Gunung Djati, Bandung, Indonesia (b) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (c) Department of Physics, Institute Teknologi Sumatera, Lampung, Indonesia *Corresponding author: hasniahaliah[at]uinsgd.ac.id Abstract Green-synthesized CoFe2O4/TiO2 nanocomposites utilizing Moringa oleifera leaf extract were successfully fabricated using the coprecipitation method. The green approach-based nanocomposites synthesizing is considered to be an eco-friendly and cost-effective method to fabricate nanocomposites compared to the other conventional methods. Nanocomposites exhibited excellent photocatalytic and reusability performance under UV irradiation. Various techniques were employed to characterize the properties of green-synthesized CoFe2O4/TiO2 nanocomposites, such as UV visible spectroscopy, X ray diffraction (XRD), transmission electron microscopy, Fourier transform infrared spectroscopy, and vibration sample magnetometer. Photocatalytic activity of CoFe2O4/TiO2 nanocomposites in degrading methylene blue (MB) dye has been successfully carried out. The investigation of photocatalytic activity was carried out with several variations of the mass of the CoFe2O4/TiO2 nanocomposite of 0.02, 0.04, 0.06, 0.08, and 0.1 gram. The results of the characterization using XRD showed that the crystallite size of CoFe2O4/TiO2 was 11.3 nm. The magnetic hysteresis curve showed that CoFe2O4/TiO2 had a high saturation magnetization of 27 emu/g and a coercivity of 200 Oe. The optical bandgap energy for CoFe2O4/TiO2 was in the range 3.6 until 3.8 eV. The characterization of photocatalyst activity showed an increase in the percentage of degradation by the increase of photocatalyst concentration. Variations in the mass of the catalyst affect the degradation process, with a mass of 0.06 gram being the effective mass in degrading MB with the degradation efficiency of 97%. CoFe2O4/TiO2 nanocomposites can be recycled and used three times with a degradation efficiency above 95%. Nanocomposites can still be reused to degrade MB again with degradation efficiency of almost constant. Therefore, the green synthesized CoFe2O4/TiO2 has great potential as magnetically separable and reusable photocatalyst for water purification. Keywords: CoFe2O4/TiO2- Green Synthesis- Methylene Blue- Photocatalyst- Nanocomposites Share Link | Plain Format | Corresponding Author (Citra Dwi Lestari)

35	Energy and Environmental Physics	ABS-97
Heavy Metal Ions Removal from Aqueous Solutions using NiZnFe2O4/TiO2 Nanocomposites Absorbent Siska Irma Budianti, Nurul Imani Istiqomah, Edi Suharyadi* Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract This study investigates the adsorption performance of NiZnFe2O4/TiO2 nanoparticles on heavy metal of Cr(VI). NiZnFe2O4/TiO2 nanoparticles were successfully synthesized using coprecipitation and stober methods with various molar ratios of TiO2. The samples were characterized using x ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive x ray (SEM EDX), fourier transformation infra-red (FTIR), vibrating sample magnetometer (VSM), and ultraviolet-visible spectroscopy (UV Vis) to analyze their crystal structure, morphology, chemical bond formation, optical properties, magnetic properties, and removal efficiency. XRD results showed that NiZnFe2O4 and TiO2 have a cubic and tetragonal structure. The crystallite size decreased as the TiO2 concentration increased. TEM image of NiZnFe2O4 shows that it forms clusters and is not evenly dispersed under agglomerated conditions, with an average particle size of (10.6 plus minus 0.8) nm. FTIR analysis showed functional groups O H, C H, and H O H which indicated successful synthesis. In addition, the presence of MO octahedral, MO tetrahedral, and Ti O functional groups indicated that NiZnFe2O4/TiO2 nanoparticles had been formed. The addition of TiO2 affected to the saturation of magnetization and coercivity value in the range of 12.4 until 22.9 emu/g and 47 until 55 Oe, respectively, which indicated good magnetic properties. The absorbance spectrum of these nanoparticles was shifted to the right (redshift) so they could absorb the ultraviolet rays. The band gap of these nanoparticles varies from (2.85 plus minus 0.02) until (3.29 plus minus 0.02) eV. NiZnFe2O4/TiO2 nanoparticles with a concentration of 1:5 have good Cr(VI) removal efficiency and can reach a degradation value of 65.6%. The pseudo-kinetic model was first investigated to describe kinetic data and Cr(VI) removal determination. The SEM EDX of adsorbent after adsorption showed the presence of Cr(VI) in the nanocomposite. Therefore, these results can promote NiZnFe2O4/TiO2 nanoparticles as a promising candidate in the removal of heavy metal waste. Keywords: Adsorption- Nanoparticles- NiZnFe2O4- Removal- TiO2 Share Link | Plain Format | Corresponding Author (Siska Irma Budianti)

36	Energy and Environmental Physics	ABS-98
Study of CO2 injection into Sumatran shale layers to increase gas production of the shale gas field as well as effectiveness of gas carbon capture in the atmosphere 1Bagus Endar B. Nurhandoko, 2Erlangga Septama, 2Totong Kusnadi Usman, 2Pongga Dikdya Wardaya, 3Eko Bambang Supriyanto, 3Kaswandhi Triyoso, 3)Susilowati 1Ratih Pratiwi, 1Maria Cindrawati, 2Vida Irene Rosa, 2Richie R. Pratama 1)Physics Dept., Institut Teknologi Bandung 2)Upstream Research & Technology Innovation, Pertamina Persero 3)Rock Fluid Imaging Lab Abstract Injecting CO2 into a reservoir has some important reasons. CO2 injection can enhance oil and gas recovery by reducing the capillary pressure, increasing the pressure gradient, and changing the phase behavior of the fluids. It can reduce the greenhouse gas emissions by capturing and storing CO2 underground. It can also create economic benefits by utilizing CO2 as a valuable resource and generating revenue from carbon credits. Therefore, injecting CO2 into a reservoir benefits the environment and the industry. We can inject CO2 in shale gas reservoirs to increase productivity because CO2 has a stronger adsorption capacity on shale surfaces than hydrocarbon gas. When CO2 is injected into shale reservoirs, it can displace the adsorbed CH4 flow out of the micropores and free up more space for gas flow. Injecting CO2 can also reduce the viscosity and density of shale gas, improving its mobility and transport. Moreover, injecting CO2 can provide environmental benefits by reducing carbon emissions and storing CO2 underground. Therefore, CO2 injection is a promising technique for enhancing shale gas recovery and mitigating climate change. In this study we characterized several types of shale from Sumatra using XRD to determine the mineral content, Scanning Electron Microscope to determine the pore structure and layers, EDX energy dispersion x-ray spectroscopy to determine the elemental content. We also measure the porosity of free gas from several Sumatran shales with helium gas for an analogy to the inert gas methane or other hydrocarbon gases. Adsorbed and desorbed porosity measurements were also carried out by hydrocarbon gas injection. This measurement is compared with CO2 gas injection measurements. The results of adsorbed and desorbed porosity measurements of helium gas and CO2 gas for each type of shale show the effectiveness of Enhanced Gas Recovery in shale gas layers in Sumatra. Keywords: CO2 injection, shale gas, enhance recovery, adsorbed porosity, desorbed porosity, mineralogy Share Link | Plain Format | Corresponding Author (Bagus Endar B. Nurhandoko)

37	Energy and Environmental Physics	ABS-107
The Effect of Varying Composition of Peanut Shell and Palm Oil Shells Briquettes on the Physical Properties of Briquettes Yusraida Khairani Dalimunthe (a)(b), Widayani (a*), Irfan Dwi Aditya (a) a) Biophysics Research Group, Dep. Of Physics, FMIPA ITB, Jalan Ganesha 10, Bandung 40132, Indonesia b) Petroleum Engineering, Faculty of Technology Earth and Energy, Universitas Trisakti, Jakarta, 11440, Indonesia *widayani[at]itb.ac.id Abstract The aim of this research is to determine the physical properties of briquettes made from peanut shell (KKT) and palm oil shell (CKS) waste. The manufacturing process is carried out using a briquette press with a pressure of 70 N/m2 and each KKT and CKS measuring 100 mesh, 2 grams of starch adhesive and 15 ml of water. This research method was created by varying the number of KKT and CKS with a ratio of 18:0, 16:2, 14:4, 12:6, 10:8, 8:10, 6:12, 4:14, 2:16, 0: 18. The results of this research showed that the density values obtained were in the range 708.38 kg/m3 to 876.91 kg/m3, then the modulus of elasticity values obtained were in the range 17.10x103 Pa to 6x10-7 Pa and the ultimate strength values obtained is in the range 13.59x105 Pa to 60.34x105 Pa. Keywords: renewable enrgy- briquette- biomass- peanut shell- palm oil shell Share Link | Plain Format | Corresponding Author (Yusraida Khairani Dalimunthe)

38	Energy and Environmental Physics	ABS-113
Preliminary Study of the Specific Capacitance of Supercapacitor Electrode Prepared from Carbonized Bituminous Raw Coal Mohamad Samsul Anrokhi (a), Oktaviardi Bityasmawan Abdillah(a), Pipit Fitriani (a,b), Fatimah Arofiati Noor (a), and Ferry Iskandar (a*,b) (a) Physics of Electronic Materials Research Group, Dep. of Physics, FMIPA ITB (b) Reseach Center of Nanosceinece and nanotechnology (RCNN), Institut Teknologi Bandung. Bandung, Indonesia. Email: ferry[at]itb.ac.id Abstract A bituminous grade coal is promising and cost-effective raw material for supercapacitor electrodes application. Carbonization plays a crucial role in transforming the organic components present in raw coal into a carbon-rich structure with an enhanced capacity for charge storage. In this research, we study the specific capacitance of electrode prepared from the carbonized bituminous coal as a preliminary evaluation of its electrochemical properties. The carbonized bituminous coal was synthesized through a simple heat treatment at temperatures of 7000C and 9000C under a continuous flow of argon gas for 2 hours. The structural behavior of carbonized bituminous coal was analyzed using several characterizations, including Raman spectroscopy, x-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Furthermore, the electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic charge discharge in a 3 M electrolyte solution of potassium hydroxide (KOH) with a three-electrodes configuration. The specific capacitances of 49.75 Fg-1 and 20.00 F g-1 at a current density of 0.5 Ag-1 were achieved for the sample produced at the carbonization temperature of 7000C and 9000C, respectively. These values are considerably higher than the specific capacitance of raw bituminous coal (0.687 F g-1) at 0.5 Ag-1. This result may offer valuable insight for the further development of coal-based supercapacitor electrodes. Keywords: Coal, carbonization, specific capacitance Share Link | Plain Format | Corresponding Author (Ferry Iskandar)

39	Instrumentation, Acoustics and Signal Processing	ABS-37
Utilization of Histogram of Oriented Gradients and Machine Learning in Face Recognition System Muhammad Ervandy Rachmat, Irfan Dwi Aditya, Fahdzi Muttaqien Institut Teknologi Bandung Abstract The development of computer science and technology in recent years has experienced great developments, this time there are types of technology that digitize almost everything related to human life, including human facial recognition. In recent years various methods for recognizing human faces have developed, one of them is using the Histogram of Oriented Gradients (HOG). On this occasion, an image processing system will be designed to recognize human faces using Histograms of Oriented Gradients (HOG) and machine learning such as Convolutional Neural Networks (CNN), and Support Vector Machines (SVM). detects the winking of the face, using computer-recognizable points in the eye area from 68 facial landmarks, so from these results the distance between the upper and lower eyelids can be measured, which if the distance (in pixels) is small enough, it can be interpreted as a wink. In addition, it is also limited by the distance of faces that can be detected to blink. In the end, if the blinking of a recognized face is detected, the time and date will be recorded which will then also open a solenoid lock using serial communication via Arduino Uno so that it can become a security system. From 100 facial photos and 207 blink tests, 89.86% found that the computer could detect a ^True Positive^ wink, besides that the recommended tolerance parameter value for this facial recognition system is between 0.42 to 0.48. Keywords: face, histogram of oriented gradients, image processing, machine learning Share Link | Plain Format | Corresponding Author (Muhammad Ervandy Rachmat)

40	Instrumentation, Acoustics and Signal Processing	ABS-96
Detection of Green-Synthesized Fe3O4/Ag Composite Nanoparticles as Magnetic Labels for GMR-Based Biosensor Applications Dani Muhammad Hariyanto (a), Zurnansyah (a), Nur Aji Wibowo (b), Mahardika Yoga Darmawan (a)(c), Harlina Ardiyanti (a)(c), Nurul Imani Istiqomah (a), and Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Department of Physics, Universitas Kristen Satya Wacana, Salatiga, Indonesia (c) Department of Physics, Institut Teknologi Sumatera, Lampung, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract In the research of giant magnetoresistance (GMR) biosensing technology, it is crucial to investigate the magnetic labels and their characteristics on the sensor signal performance. This study uses a commercial GMR chip AAL024 equipped with a basic differential amplifier circuit and an arduino microcontroller (AM) for directly detecting green synthesized Fe3O4/Ag composite nanoparticles (NPs) as a magnetic label. The Fe3O4 magnetic nanoparticles (MNPs) were synthesized by a chemical coprecipitation method utilizing Moringa Oleifera extract as a green reducing agent. Meanwhile, surface modification with Ag NPs was conducted to cover the deficiency of Fe3O4, which is easily agglomerated and oxidized. The X ray diffraction results demonstrate that Fe3O4 and Fe3O4/Ag have cubic inverse spinel structure with crystallite size of 5.7 nm and 11.2, respectively. The larger crystallite size obtained explains the successful formation of composites between Fe3O4 MNPs and Ag NPs. The scanning electron microscopy images illustrate the granular shapes with non homogeneous distribution on the surface of Fe3O4 and Fe3O4/Ag composite, while energy dispersive X ray spectrums confirm the presence of Fe element percentage of 70.9% and 61.7% for both investigated samples. The magnetic properties study shows that saturation magnetization of Fe3O4/Ag composite is 43.2 emu/gr, and it is lower than Fe3O4 MNPs. Furthermore, sensor performance is examined by sensitivity and limit of detection (LOD) obtained. The sensor sensitivity of Fe3O4 is 5.67 mV(mg/mL), and Fe3O4/Ag with different Ag concentrations are in the range of 3.99 until 4.24 mV(mg/mL). The smallest LOD value is obtained by Fe3O4/Ag 60 mM with 0.75 mg/mL. Therefore, these promising performances demonstrate the potential of green synthesized Fe3O4/Ag composite NPs as a suitable candidate for magnetic labels in GMR biosensor applications. Keywords: Giant Magnetoresistance- Green-Synthesized- Fe3O4/Ag- Magnetic Labels- Commercial GMR Share Link | Plain Format | Corresponding Author (Dani Muhammad Hariyanto)

41	Interdisciplinary Physics	ABS-34
Application of Restricted Boltzmann Machine as Feature Extracting in Predicting the Trend of Indonesia Stock Market Price Marshanda Tiana Sarjito (a) (a) Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Indonesia Abstract Econophysics is an interdisciplinary science that applies physics in solving economic phenomena. One of the focuses of econophysics is the study of the stock market. Making predictions for the stock market is very important because it can provide financial decisions to investors. Many approaches have been done in predicting stock prices such as statistical models, machine learning, and deep learning. However, the use of high dimensional data such as stock prices allows a reduction in computational performance so that a deep learning model, Restricted Boltzmann Machine (RBM), is proposed as a feature extracting. The purpose of this study is to analyze the effect of RBM in predicting stock price trends and compare Gaussian RBM with Bernoulli RBM. This research was conducted by adding RBM in the prediction of stock price trends carried out for three stock prices namely ASII, BMRI, and TLKM using Support Vector Machine (SVM), Random Forest, Naive Bayes Classifier, and Multi Layer Perceptrons Classifier. The results of the prediction are in the form of accuracy values that are evaluated using matrix evaluation. From this research, it is concluded that the use of RBM has an influence on the resulting accuracy value and the use of Bernoulli RBM is better than Gaussian RBM. Even so, there are some stock data and prediction classification models that do not show the influence of RBM. This can be caused by many factors such as data characteristics, classification model selection, and RBM hyperparameter selection. Keywords: Accuracy, Bernoulli RBM, Gaussian RBM, Prediction. Share Link | Plain Format | Corresponding Author (Marshanda Tiana Sarjito)

42	Magnetism and Photonics	ABS-16
Synthesis and Characterization of Hematite (Fe2O3) from Iron Sand Using Coprecipitation Method Ramlan, Ahkmad Aminudin Bama, Akmal Johan, Marzuki Naibaho, Masno ginting 1. Department of Physics, Faculty of Natural Sciences, Sriwijaya University, Inderalaya, Ogan Ilir (OI). South Sumatera. 30662. Indonesia 2. Research Center for Advanced Materials (PRMM), Nasional Research and Inovation Agency (BRIN), Serpong, South Tangerang, Indonesia Abstract Hematite (Fe2O3) has been synthesized from iron sand using the copresipitation method. This study aims to determine the morphology and mineral content using SEM EDX, crystal structure and phases formed using XRD, and magnetic properties using VSM on iron sand before and after synthesis. SEM EDX result show that the average particle size of iron sand before and after synthesizing is 356.23nm and 12.40 micrometer, respectively. XRD results show that iron sand before synthesizing has miltiphase including hematite, Magnetic, Ilmenite and after synthesizing produces single phase hematite. VSM results show that iron sand before synthesizing has saturation, remanace, and coercivity of 47.56 emu/g, 5.97 emu/g, 121.03 Oe respectively and after synthesizing has saturation, remanace, and coercivity of 9.47 emu/g, 1.53emu/g and 102.97 Oe respectively. Keywords: Iron Sand, Coprecipitation, Hematit, Ferrimagnetic, Soft Magnet Share Link | Plain Format | Corresponding Author (Marzuki Naibaho)

43	Magnetism and Photonics	ABS-89
Photocatalytic Degradation of Methylene Blue using Green Synthesized Fe3O4/rGO/ZnO Magnetic Nanocomposite Utilizing Moringa Oleifera and Amaranthus Viridis Leaf Extract Nugraheni Puspita Rini (a), Larrisa Jestha Mahardhika (a), Hafil Perdana Kusumah (a), Zurnansyah (a), Putri Dwi Jayanti (a), Rivaldo Marsel Tumbelaka (a), Nurul Imani Istiqomah (a), Nining Sumawati Asri (b), Hasniah Aliah (c), and Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Research Center for Advanced Materials, National Research and Innovation Agency (BRIN), Tangerang Selatan, Indonesia (c) Department of Physics, UIN Sunan Gunung Djati, Bandung, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract Fe3O4 nanoparticles easily agglomerate into larger particles, reducing specific surface area and dispersibility and limiting catalytic activity. ZnO is attached on rGO surface, wrapped Fe3O4 magnetic nanoparticles, whereas rGO acts as efficient interlayer to optimize synergistic impact of ZnO and Fe3O4 and enhance photocatalytic activity. Herein, we report magnetically separable, green synthesized Fe3O4/rGO/ZnO, as heterogeneous catalyst for photo Fenton degradation of organic pollutants in aqueous solution under certain treatments. Fe3O4 nanoparticles was green synthesized under coprecipitation method using Moringa oleifera leaf extract, while rGO was fabricated by sonicating GO which has been added with hydrazine. Fe3O4/rGO was composited under sonication treatment. Afterwards, Fe3O4/rGO/ZnO was green synthesized using precipitation method with Amaranthus viridis leaf extract addition. X ray diffraction and selected area electron diffraction showed that Fe3O4 and ZnO had spinel cubic and hexagonal structure, respectively- another phase appeared as Fe2O3 spinel cubic structure. Crystallite size was increased as the ZnO concentration increased. Morphology image showed almost spherical, non uniform, and slightly dispersed particle under agglomerated condition, attaching to rGO sheets. Green synthesized Fe3O4, Fe3O4/rGO, and green synthesized Fe3O4/rGO/ZnO with molar ratio of 1:1 had average particle size of 14.3- 14.2- and 10.4 nm, respectively. Besides, the corresponding chemical elements were confirmed by energy dispersive X ray spectroscopy. Fourier transform infrared spectra showed metallic functional groups, such as Fe O and Zn O at 562 until 589 and 462 until 478 cm (minus one) also suggests nanoparticles formation. However, blue shift absorption and band gap widening were observed with ZnO addition. Vibrating sample magnetometer showed that green-synthesized Fe3O4/rGO/ZnO exhibited superparamagnetic properties. Removal efficiency of photodegradation methylene blue was optimal for green synthesized Fe3O4/rGO/ZnO under sonication treatment, reached 100% degradation within 3 h for uptake every 30 min. Photodegradation was also analyzed using Langmuir Hinshelwood kinetic model, resulting rate constant of 34.4 (times ten to the power of minus three) (minus one) and half life time of 20.1 min at optimum treatment. Reusability of photocatalytic activity after 3 cycles showed only a tiny drop in catalytic efficiency. Meanwhile, it possesses high stability in catalytic activity and structure. Keywords: Photocatalytic activity- Methylene blue- Reusability- Green synthesized- Fe3O4/rGO/ZnO- Magnetic- Nanocomposite Share Link | Plain Format | Corresponding Author (Nugraheni Puspita Rini)

44	Magnetism and Photonics	ABS-92
Concentration Dependences of Photocatalytic Activity in Green-Synthesized Fe3O4/rGO/TiO2 Composite Nanoparticles for Degradation of Methylene Blue Dye Hanif Yoma Khoiri (a), Larasati Hayu Regita Salma (a), Hafil Perdana Kusumah (a), Larrisa Jestha Mahardhika (a), Rivaldo Marsel Tumbelaka (a), Nugraheni Puspita Rini (a), Nurul Imani Istiqomah (a), Nining Sumawati Asri (b), and Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Research Center for Advanced Materials, National Research and Innovation Agency (BRIN), Tangerang Selatan, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract The textile industry, printing, dyeing, and other manufacturing are the largest contributors to wastewater, especially organic dyes such as methylene blue (MB). MB has complicated aromatic molecules that are difficult to degrade and cause serious problems for the natural environment. Photocatalysis has gained popularity in wastewater treatment due to its affordability and effectiveness. TiO2 is a semiconductor material that is excellent for photocatalytic activity because of its small bandgap energy and only being excited by UV light, but due to its nanoscale size, TiO2 is difficult to separate from water solutions. Besides, electron-hole pairs have a high recombination rate, so the reactivity will rapidly diminish. Due to high recombination of TiO2, reduced graphene oxide (rGO) is an electron acceptor and promising applications in various fields especially photocatalytic. Fe3O4 is superparamagnetic materials offer a wide range of uses for recovering catalysts and are sensitive to external magnetic fields. This study investigates photocatalytic degradation of Fe3O4/rGO/TiO2 nanoparticles green synthesized utilizing Moringa oleifera and Amaranthus viridis extract. The activity of photodegradation of MB was investigated using Fe3O4/rGO/TiO2 photocatalyst with various concentration. The X ray diffraction showed that Fe3O4 has an inverse cubic structure, TiO2 has a tetragonal structure, and low intensity rGO peaks at around 18 degrees. SEM/EDX confirmed the formation of Fe3O4/rGO/TiO2 with concentration of 5:1:1, which is dominated by Fe and O rather than C and Ti. Uv vis spectroscopy showed the bandgap values of Fe3O4, rGO, Fe3O4/rGO, and Fe3O4/rGO/TiO2 were 3.06, 4.06, 3.19, and 3.23 eV respectively. The highest degradation efficiency reached 98%. The addition of Fe3O4 simplifies the separation process. The presence of rGO and TiO2 makes the photoexcited electron-hole pairs increase and reduce the recombination process. Moreover, because it uses the green synthesis method, it will not be harmful to the environment. Therefore, Fe3O4/rGO/TiO2 has great potential in photocatalysis for water purification. Keywords: Green-synthesized- Nanoparticles- Photocatalyst- Methylene blue Share Link | Plain Format | Corresponding Author (Hanif Yoma Khoiri)

45	Magnetism and Photonics	ABS-94
Mass Dependent Photocatalytic Degradation of Methylene Blue using Green Synthesized Fe3O4/rGO Nanocomposites Utilizing Moringa Oleifera and Amaranthus Viridis Leaf Extracts Larasati Hayu Regita Salma (a), Larrisa Jestha Mahardhika (a), Hanif Yoma Khoiri (a), Hafil Perdana Kusumah (a), Rivaldo Marsel Tumbelaka (a), Nurul Imani Istiqomah (a), Nining Sumawati Asri (b), and Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), Tangerang Selatan, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract Methylene Blue (MB) has gained popularity as one of the most used dyes in the textile industry. This dye is non biodegradable and difficult to degrade aromatic molecular structures therefore making this organic dye waste harmful to the environment. Photocatalysis is considered as a promising and cost effective method for separating organic compounds from wastewater by light induction on a specific wavelength. It is a process where the catalyst enhances oxidation rate and reduction reactions. rGO is a graphene based material that is involved in the development of photocatalyst nanocomposite to treat polluted wastewater with boosted photocatalytic activity. The disadvantage of this material is the difficulty to remove from the treated water. Magnetite (Fe3O4) is known as a superparamagnetic material and is highly responsive under external magnetic fields. Incorporating rGO in the photocatalysis process with the addition of metals offers the possibility for the separation of the catalyst while giving maximum pollutant removal from the wastewater. In this study, Fe3O4/rGO nanocomposite was successfully synthesized using a green synthesis method with Moringa oleifera and Amaranthus viridis leaf extracts to obtain a nanomaterial with the ability to be magnetically separated and performs adequate photocatalytic activity. The activity of photodegradation of MB was investigated using Fe3O4/rGO photocatalyst with various mass of catalyst. The Fe3O4 and rGO samples were composited, resulting in Fe3O4/rGO nanocomposite with the concentration ratio of 5:1 and then characterized using XRD, SEM/EDX, Uv Vis, and VSM to investigate the crystal structure, elemental composition, optical and magnetic properties, respectively. The crystallite size for Fe3O4 is calculated from XRD characterization resulting in the structure of inverse cubic. SEM/EDX result shows that the sample of Fe3O4/rGO is predominantly Fe, with few segments of O and rGO sheets. Uv Vis characterization using Tauc plot yields Fe3O4/rGO, Fe3O4, and rGO bandgaps as 3.16 eV, 3.20 eV, and 4,19 eV respectively. The sample of Fe3O4/rGO gives a photodegradation rate up to 77.1 percent, thus showing the material has notable potential in photocatalysis. Keywords: Fe3O4/rGO nanoparticles- Green synthesis- Magnetic- Methylene blue- Photocatalysis Share Link | Plain Format | Corresponding Author (Larasati Hayu Regita Salma)

46	Magnetism and Photonics	ABS-104
Optimization of Organic Capping Material on Silver Nanoparticles by Chemical Reduction and It Functionalization for Plasmonic Sensor Application Qoid Abrori Syakuro, Yoda Taruna, Setiya Rahayu, Herman, Priastuti Wulandari Physics of Magnetism and Photonics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung 40132, West Java, Indonesia. *pwulandari[at]itb.ac.id Abstract The application of metal nanoparticles related to the nanotechnology in medicine and optoelectronic devices have shown remarkable results. It has been known that metal nanoparticles such as gold and silver show unique optical properties called localized surface placement resonance (LSPR). LSPR is an effect that corresponds to the interaction between electromagnetic wave and the conductive matter of the metal nanoparticles. This interaction generates coherent localized plasmon oscillations with frequency that depends on the size and shape of the nanoparticle. In general, metal nanoparticles need capping material in order to prevent metal core from aggregation and also to provide surface passivation. In the application of biosensor, organic material such as thiol-derivatives and citrate are often used because of its high affinity with gold and silver, LSPR enhancement effect, and the ability to link biomolecule for biosensor application. Herein, we present the optimization study of organic capping molecules on silver nanoparticles (AgNP) by used of modified chemical reduction method to form stable AgNP with homogenous in size and shape. In our case, we modified the capping materials of AgNP by used of trisodium citrate and 3-mercaptopropionic acid (3-MPA) which both solved in water and they are easy to functionalize with biomaterial for application in plasmonic sensor. The optimization of AgNP was done by varying the ratio among the concentration of the precursor (AgNO3), reducing agent and capping materials. We investigated the optical characteristic of the AgNP by UV-Vis spectroscopy and its chemical characteristic through FTIR spectroscopy, while the morphology of AgNP was captured by TEM. Our AgNP products show bright yellow to dark brown color of solution with the plasmonic absorbance peak for citrate capped AgNP (Ag-Citrate) at 410-424 nm and 3-MPA capped AgNP (Ag-MPA) at 428-440 nm. FTIR spectra show the difference shift of COO- bond for Ag-Citrate and Ag-MPA. The TEM images for both samples of AgNP show the spherical shape with the range of diameter size 5-38 nm which depend on the given ratio of material concentration in the synthesis process. Keywords: Localized Surface Plasmon Resonance, silver nanoparticles, 3-Mercaptopropionic Acid, Trisodium Citrate. Share Link | Plain Format | Corresponding Author (Qoid Abrori Syakuro)

47	Magnetism and Photonics	ABS-111
Nonlinear Coefficient Optimization in Emerging Silicon Nitride Waveguides for High Conversion Efficiency of Four Wave Mixing Process Dharma P. Permana (a), Yvan Klaver (b), David A. Marpaung (a,b), Alexander A. Iskandar (a*) (a) Physics of Magnetism and Photonics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Indonesia *a.a.iskandar[at]itb.ac.id (b) Nonlinear Nanophotonics, MESA+ Institute of Nanotechnology, University of Twente, Enschede, the Netherlands Abstract Efficient single photon source is one of the important components needed to operate chip sized photonic quantum circuits and quantum processor for practical applications of quantum computer. A promising candidate for efficient single photon source integration to the existing quantum processor and quantum circuits can be achieved by utilizing four wave mixing (FWM) process in nonlinear optical media. Strong FWM can be achieved by enhancement of nonlinear coefficient which depends on the intrinsic properties of materials and optical properties of the waveguide. Taking into consideration the value of nonlinear index, refractive index, broad transparency window, and negligible effect of two photon absorption, silicon nitride (SiN) is chosen as the material platform, while double stripe waveguide is chosen as the platform geometry due to its low propagation loss, tight optical confinement, and can be fabricated with COMS-compatible technologies with high yield. However, the major problem of employing emerging waveguide designs (such as the double stripe waveguide) is the inaccuracy of the commonly used nonlinear coefficient calculation model which known as scalar model due to its weakly guiding approximation. Another approach to calculate the nonlinear coefficient in the strong guidance regime has been developed in the form of vectorial model, and perturbative model. In this work, we used scalar, vectorial, and perturbative models to numerically calculate the nonlinear coefficients of several structure with experimental demonstrations of FWM process in order the determine the accuracy of each model. The results of our calculations shows that the each of the models accuracy changing depends on the fabrication methods of the SiN waveguides- thus, no models can consistently gives accurate results of nonlinear coefficients. Despite, none of the models can consistently give accurate value of the nonlinear coefficients, these models can predict the optimum thickness value which posses the largest nonlinear coefficient. By doing thickness variation of single stripe SiN waveguides, all the models shows that the nonlinear coefficient peaked around 400 nm and 500 nm thickness simultaneously. Further, we^ve done optimization of double stripe waveguides by changing the stripes thickness and varying the gap between each stripe to find the optimum gap and thickness value with largest nonlinear coefficient. From this optimization we found that the optimum stripe thicknesses needed to achieve maximum value of the nonlinear coefficient also increases with the increment of gap size, while the peak value of the nonlinear coefficient simultaneously decreasing for all models with the increment of gap size. Keywords: nonlinear coefficient- inhomogeneous cross section- high index contrast- four wave mixing- double stripe waveguide- silicon nitride Share Link | Plain Format | Corresponding Author (Dharma Prasetya Permana)

48	Material Physics	ABS-4
Enhanced Superabsorbency of Cellulose-Based Hydrogels in NaOH Solution: Synthesis, Characterization, and Performance Evaluation Nuraini Nafisah (a), Marathur Rodhiyah (a), Halida Rahmi Luthfianti (a), William Xaveriano Waresindo (a), Bagas Haqi Arrosyid (d), Alfian Noviyanto (d), Dian Ahmad Hapidin (a,b), Dhewa Edikresnha (a,b), Khairurrijal Khairurrijal (a,b,c*) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia b) University Center of Excellence - Nutraceutical, Bioscience, and Biotechnology Research Center, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia c) Department of Physics, Faculty of Sciences, Institut Teknologi Sumatera, Jl. Terusan Ryacudu, Lampung 35365, Indonesia d) Nano Center Indonesia, Jalan Raya PUSPIPTEK, South Tangerang, Banten 15314 Indonesia *krijal[at]itb.ac.id Abstract Cellulose is a natural polymer that is abundantly available in nature. This study successfully developed cellulose dissolved in NaOH and formed into hydrogels using the freeze-thaw method. NaOH solution concentration as a cellulose solvent varied from 1% (CN1) to 5% (CN5) by weight. Six cycles of freezing and thawing were performed for 20 hours at -23\(^\circ\)C and 4 hours at 37\(^\circ\)C. Subsequently, morphological analysis, swelling degree, weight loss, and compression testing were conducted to assess the physical properties of cellulose-based hydrogels. The results demonstrate that as the concentration of NaOH increases, the resulting hydrogel exhibits smaller pore sizes, as evidenced by optical microscope images. Additionally, the swelling degree increased with the increasing NaOH fraction. The swelling tests were performed in both distilled water and PBS solutions. Notably, soaking the hydrogels in PBS solution demonstrated their potential as superabsorbent hydrogels (SAH). Furthermore, increased NaOH fraction was associated with higher weight loss, greater Young^s modulus, and reduced compressive strength. Keywords: hydrogel, cellulose, NaOH, super absorbent, freeze-thaw Share Link | Plain Format | Corresponding Author (Nuraini Nafisah)

49	Material Physics	ABS-5
BLOW-UP RATIOS EFFECT ON LLDPE FILMS PROPERTIES WITH DIFFERENT MATERIAL TYPES Bayu Krisnamurti, Mas Ayu Elita Hafizah, Azwar Manaf Departement of Physics,Faculty of Mathematics and Natural Sciences. University of Indonesia. Depok, Indonesia Abstract This research explores producing high-impact LLDPE films for flexible packaging, focusing on the influence of the blow-up ratio (BUR) in the blown film extrusion process. LLDPE films with varying material grades were produced using a mini blown film extrusion process, with BUR systematically varied between 1.5 to 2.45. Standardized tests evaluated mechanical properties and thickness. The best sample, with material & ratio variation 1.3 and BUR 2.0 (LLDPE/Hexene Copolymer & Plastomer mixture), showed outstanding impact strength and tearing resistance among of the references sample and another material type & variation. Differential scanning calorimetry (DSC) analyzed thermal properties for optimal high-impact LLDPE films. The research also aims to identify optimal parameters for high-impact LLDPE films suitable for mono-material applications in flexible packaging. LLDPE outstanding mechanical and thermal properties have drawn attention across industries. A mini blown film extrusion process produced LLDPE films with varying material grades, while BUR ranged from 1.5 to 2.45. Mechanical properties, including tensile strength, elongation, Young modulus, impact resistance, tearing strength, and thickness, were evaluated. The best optimization sample achieved an impact strength of 2,808 J/mm2 with a 25% increase in outer/inner positions compared to references. Tensile strength values were 50/48 N/mm2 in MD/TD positions, with elongation reaching 870/825%. Secant Modulus was 100/55 in MD/TD positions, and thickness variations were observed across the BUR range. Tearing strength measurements resulted in 872/843 gram-forces in MD/TD positions, highlighting the best material and BUR combination LLDPE for flexible packaging. The research also investigated film sealing strength using the sealing initiation temperature (SIT), confirming excellent sealing integrity at lower temperatures. DSC analysis provided insights into thermal properties for creating High Impact LLDPE films in flexible packaging applications. In conclusion, this research identifies optimal parameters for high-impact LLDPE films, enhancing their suitability for flexible packaging applications and contributing to sustainability in the flexible packaging industry. Keywords: Blow Up Ratio, Impact Strength, LLDPE, Flexible Packaging Share Link | Plain Format | Corresponding Author (Bayu Krisnamurti)

50	Material Physics	ABS-8
Electrical Resistivities of PVA/Activated Carbon-Based Hydrogels Yuan Alfinsyah Sihombing (a,b), Dhewa Edikresnha (a,c), Isa Anshori (d), Dian Ahmad Hapidin (a) and Khairurrijal Khairurrijal (a,c,e*) a) Physics of Electronic Materials Research Group, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl Ganesa No. 10, Bandung 40132, Indonesia. b) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Jl. Bioteknologi No.1, Medan 20155, Indonesia. c) University Center of Excellence-Nutraceutical, Bioscience and Biotechnology Research Center, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia. d) Lab-on-Chip Group, Biomedical Engineering Department, School of Electrical Engineering and Informatics, Institut Teknologi Bandung, Bandung 40132, Indonesia. e) Department of Physics, Faculty of Science, Institut Teknologi Sumatera, Jalan Terusan Ryacudu, Lampung 35365, Indonesia. *Corresponding Author: krijal[at]itb.ac.id Abstract This study investigates the physical and electrical properties of the polyvinyl alcohol (PVA) hydrogel incorporated with edible Activated Carbon (AC). Three samples, namely PVA, PVA/AC 0.5, and PVA/AC 1.0 were prepared using the freeze-thaw method. The samples underwent six freeze-thaw cycles, each consisting of freezing at -25\(^{\circ}\)C for 20 hours and subsequent exposure to room temperature for 4 hours. The porous network of hydrogel is attributed to the hydroxyl groups of PVA, resulting from the intermolecular cross-linking of PVA chains. The edible AC was uniformly dispersed within the hydrogel network, leading to a reduction in hydrogel pores. As a result, the electrical resistivity of PVA, PVA/AC 0.5, and PVA/AC 1.0 hydrogels measured 1052.9\(\pm\)165.0 \(\Omega\).cm, 403.1\(\pm\)29.2 \(\Omega\).cm, and 59.9\(\pm\)4.7 \(\Omega\).cm, respectively. The incorporation of edible AC significantly decreased the resistivity of the hydrogel. So, this hydrogel is promising for biomedical and edible electronics applications. Keywords: PVA, Activated Carbon, hydrogel, physical and electrical properties, electrical resistivity. Share Link | Plain Format | Corresponding Author (Yuan Alfinsyah Sihombing)

51	Material Physics	ABS-26
PAN/PSU/SiO2 Nanofiber Membranes: Characterization and Prospects for Air Filtration Rizky Aflaha (a), Linda Ardita Putri (a), Aditya Rianjanu (b), Roto Roto (c), Kuwat Triyana (a*) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, BLS 21, Yogyakarta 55281, Indonesia. *triyana[at]ugm.ac.id (K.T) b) Department of Materials Engineering, Institut Teknologi Sumatera, Terusan Ryacudu, Way Hui, Jati Agung, Lampung 35365, Indonesia c) Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, BLS 21, Yogyakarta 55281, Indonesia Abstract In recent times, the employment of nanofibers as membranes for air filtration has garnered significant attention, primarily due to their promising performance attributes. This study focuses on the realm of air filtration by investigating polyacrylonitrile (PAN) nanofibers that have been enriched with polysulfone and silicon dioxide (SiO2). The central objective is to uncover the inherent potential of these composite nanofibers as air filtration membranes. The study comprehensively analyzes the distinctive properties inherent in the fabricated nanofibers. Through scanning electron microscopy (SEM), intricate details regarding the morphological features of the nanofibers are unveiled, offering valuable insights into their underlying structural characteristics. In parallel, the study employs Fourier-transform infrared (FTIR) analysis to delve into the chemical composition of the doped nanofibers, thereby illuminating critical factors that influence their filtration performance. An indispensable facet of filtration membranes is their interaction with water, a characteristic addressed through water contact angle (WCA) measurements. The amalgamation of these multifaceted attributes uniquely situates the fabricated nanofibers as prime contenders for the role of air filtration membranes. Notably, their capacity to proficiently repel water and nuanced comprehension of their structural configuration, composition, and hydrophobic nature collectively bestow an elevated potential for enhanced filtration efficiency. These tailored nanofibers, fashioned through the amalgamation of polyacrylonitrile, polysulfone, and silicon dioxide, augur a compelling solution for the intricate realm of advanced air filtration applications. The fabricated nanofibers manifest themselves as a promising avenue for future air filtration advancements by harnessing the synergistic interplay of these distinct elements. Keywords: Nanofibers- Polyacrylonitrile- Polysulfone- Silicone dioxide- air filtration Share Link | Plain Format | Corresponding Author (Rizky Aflaha)

52	Material Physics	ABS-36
Influence of Cerium on The Structure and Optical Properties of Molydenum disulfide Grown Using DC-Unbalanced Magnetron Sputtering Aljufri Hadju (a), Azrul Kiromil Enri Auni (a), Indris Sarihon Sianturi (a), Valensius Nathanael Huangtama (a), Ridwan Muhammad Syahrul (a), Yudi Darma (a*) a) Quantum Semiconductor and Devices Lab., Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia *yudi[at]itb.ac.id Abstract We study the structure and optical properties of Ce-doped \(MoS_2\) (\(MoS_2\):Ce) deposited by DC unbalanced magnetron sputtering at room temperature. Each sample was characterized using scanning electron microscopy (SEM) and energy dispersive X-rays (EDX) to analyze the morphology and percentage of atoms. \(MoS_2\):Ce material has been successfully grown, as marked by the SEM-EDX characterization results. The morphology of \(MoS_2\) flake-shaped changed into larger particles after Ce doped. UV-Vis analysis shows a band gap shift in the values of pure \(MoS_2\) and \(MoS_2\) after Ce doping from 1.45 eV to 1.27 eV. Supporting the experimental results, our ab initio calculation shows that the band gap energy of cerium-doped \(MoS_2\) decreases resulting from the cerium contribution of density of states. This study is important for optoelectronic device application. Keywords: \(MoS_2\), DC unbalanced magnteron sputtering,Structure and optical properties Share Link | Plain Format | Corresponding Author (Aljufri Hadju)

53	Material Physics	ABS-40
Enhanced Growth of Multi Layer Graphene via Hot Wire in Plasma Very High Frequency Plasma Enhanced Chemical Vapor Deposition (HW IP-VHF-PECVD) Abd Wahidin Nuayi (a,b), Fatimah Arofiati Noor (a*), Toto Winata (a), Irzaman (c) a) Physics of Electronic Materials Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jln. Ganesha No 10, Bandung,40132 Indonesia. * fatimah[at]fi.itb.ac.id b)Physics of Materials Group, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Gorontalo Jln. Jend. Sudirman No. 06 Kota Gorontalo, Gorontalo, 96128 Indonesia. c) Department of Physics Faculty of Mathematics and Natural Sciences, IPB University, Jln. Raya Dramaga, Kecamatan Dramaga, Kab. Bogor,16680 Indonesia. Abstract The growth of multi-layer graphene has been carried out on a glass substrate using the hot wire in plasma - very high-frequency plasma-enhanced vapor deposition method. In the growth process, plasma from the precursor is generated through an rf power generator at a frequency of 70 MHz with methane gas \(CH_4\) as the precursor and Ni as the catalyst, which has been deposited and annealed beforehand. This study aimed to see the effect of the layer annealing process on the Ni catalyst layer on the graphene layer grown on it. Raman spectroscopy results with a laser beam of 532 nm (2.33 eV) and a grating of 1800 g/mm indicate the growth of the graphene layer on the surface of the Ni catalyst, with distinctive D-band, G-band, and 2D-band peaks at wave number 1335.31, 1607.74, and 2660.99 \(cm^{-1}\), respectively for samples where the catalyst layer was not annealed. Analysis of the Raman spectra, combined with the \(I_{2D}/I_G\) ratio, showed that the graphene grown in this study was a multilayer structure with ratio values ranging from 0.07-0.22, with crystal sizes varying between 15.62 - 2070 nm, which were estimated using the Tuinstra-Koenig equation. SEM analysis revealed that the annealing process on the Ni-catalyzed layer caused an increase in grain size homogeneity and thickness uniformity of the grown graphene layer, as well as revealed an increase in absorption and decreased transmittance of the graphene layer grown on the annealed Ni catalyst at higher annealing temperatures. Keywords: Multi-layer graphene- HW IP-VHF-PECVD- Raman spectroscopy- I2D/IG ratio Share Link | Plain Format | Corresponding Author (Abd Wahidin Nuayi)

54	Material Physics	ABS-75
Physical and Chemical Characterization of commercial kappa-carrageenan with Ammonium Chloride as electrolyte in organic battery application Anisah (a*), V K Sari (a), M A F Turnip (b), P Wulandari (b) and P S Rudati (c)* a) Physics of Magnetism and Photonic Research Division, FMIPA, ITB, Bandung *24722003[at]mahasiswa.itb.ac.id b) Department of Electrical Engineering, Politeknik Negeri Bandung Abstract In this research, we attempt to investigate the difference in physical and chemical characteristics between commercial kappa-carrageenan before and after purification process as electrolyte in organic battery application. Kappa-carrageenan was used as a host polymer to prepare biopolymer electrolyte films and ammonium chloride was used to enhance the charge transport process in electrolyte layer of the organic battery. Both of commercial kappa carrageenan before and after purification process were prepared in the same way in the de-ionized water as solvent together with the addition of ammonium chloride at same concentration. After the gel of kappa-carrageenan was formed then it was dropped casting on the plate and dried to take out the solvent and finally the thin film of kappa-carrageenan was ready for further used. We characterized the physical and chemical properties of kappa-carrageenan before and after purification by use of UV-Vis spectroscopy, tensile-test measurement, Fourier transform infrared spectroscopy and Raman spectroscopy in the form of solution and thin film samples. The results show that the absorbance spectra of commercial kappa-carrageenan before purification have maximum peak at 288 nm while after purification process the maximum peak of kappa-carrageenan is shifted to high wavelength at 294 nm. On the other side, the FTIR transmittance spectra and Raman spectra show no structural differences between kappa-carrageenan with or without addition of ammonium chloride. In our case, the surface morphology of the thin film of kappa-carrageenan before purification has rougher surface than the surface of purified kappa-carrageenan. While tensile test measurements indicate that kappa-carrageenan before purification is more flexible for use in organic battery manufacturing than purified kappa-carrageenan. Keywords: kappa-carrageenan- purified- electrolyte- organic battery Share Link | Plain Format | Corresponding Author (Anisah Anisah)

55	Material Physics	ABS-88
Microstructures, Magnetic, and Microwave Absorbing Properties of Bismuth Ferrite Thin Films on Kapton Sheet Wiwien Andriyanti (a)(b), Maureen Annisatul Choir Hidayati Nur (a), Tjipto Sujitno (b), Hari Suprihatin (c), Vika Arwida Fanita Sari (c), Setyo Purwanto (d), and Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Research Center for Accelerator Technology, National Research and Innovation Agency, Indonesia (c) Directorate of Laboratory Management, Research Facilities, and Science and Technology Park, Indonesia (d) Research Center for Advanced Material, National Research and Innovation Agency, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract The purpose of this research is to study the properties and performance of bismuth ferrite thin films as an absorbent material for electromagnetic waves (EM). The characterization and analytical results are expected to fulfill the criteria for an absorbent material for electromagnetic waves (EM) with high permeability and permittivity. The deposition process of bismuth ferrite thin films on Kapton substrates was carried out using DC sputtering. X-ray diffraction analysis showed the cubic crystal structure of the bismuth ferrite thin films, and it was obtained that the largest crystal size value was found in the sputtering duration sample of 10 minutes, namely 55 nm. The bonding analysis shows the presence of Bi-O and Fe-O functional groups at 432.26 and 519.48 cm (minus 1), respectively. The vibrating sample magnetometer shows the ferromagnetic behavior of the Bismuth Ferrite thin layer. It also confirms that the effect of the sputtering duration is that the longer the sputtering duration, the lower the magnetic saturation value (Ms) of bismuth ferrite thin films. The SEM-EDX analysis of bismuth ferrite thin film showed the existence of the elements Bi, Fe, and O, which were evenly distributed homogenously on the Kapton surface. The microwave absorption ability reaches a maximum reflection loss value of minus 40.4 dB (99.99%) in the range of 9.98 GHz with a sputtering duration of 10 minutes. Thus, the bismuth ferrite material was a potential candidate for applications as an electromagnetic wave absorber. Keywords: Bismuth Ferrite- DC sputtering- thin films- ion implantation- Kapton Share Link | Plain Format | Corresponding Author (Wiwien Andriyanti)

56	Material Physics	ABS-93
Microstructures and Dielectric Permittivity Properties of Fe3O4/Cdots Nanocomposites Synthesized by Green Route Utilizing Moringa Oleifera Extract and Watermelon Peel Mareta Fidya Latifa, Adhistinka Jiananda, Aldi Riyanto, Emi Kurnia Sari, Friska Suryani Sitorus, Nurul Imani Istiqomah, Edi Suharyadi* Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract Dielectric materials are highly useful for storing electrical energy due to their insulating and polarization properties in response to external electric fields. Among the other materials, magnetite has shown promise as a dielectric material due to their good magnetic properties, low toxicity, and biocompatibility. However, the weakness of Fe3O4 which has low stability and easy agglomeration requires a modification on its surface, by using Carbon dots (Cdots). This research investigates the dielectric properties of Fe3O4/Cdots obtained through green synthesis method. In this multidisciplinary research, Fe3O4 nanoparticles were synthesized using the coprecipitation method with Moringa oleifera leaf extract as a reducing and stabilizing agent. In contrast, Cdots were synthesized using hydrothermal method with watermelon peel waste as carbon source. The Fe3O4 composite nanoparticles were characterized using X ray diffraction (XRD), scanning electron microscopy energy dispersive X ray (SEM/EDX), ultraviolet visible spectroscopy (UV Vis), and impedance spectroscopy to determine their crystal structure, morphology, optical properties, and dielectric properties. The XRD spectra revealed the existence of cubic inverse spinel and a reduction in crystal size as the concentration of Cdots increased, measuring 10.4 and 6.9 nm, respectively. SEM/EDX revealed that the sample is composed of Fe, O, and C elements, has a spherical shape with Cdots distributed on the surface of Fe3O4. The UV Vis spectrum showed the absorption peak of Cdots at 282 nm. In addition, the Fe3O4 absorption peak is identical to the Fe3O4/Cdots absorption peak at 193 nm. The increase in band gap energy from 2.96 to 3.33 eV is related to the increase in Cdots concentration. In the frequency range of 10 to 900 kHz, dielectric property tests demonstrated peak dielectric permittivity values (both real and imaginary) in the 10 ml Fe3O4/Cdots sample. These values reached 314 and 104, respectively, at a 10 kHz frequency. A substantial decrease was observed between 10 kHz and 200 kHz, followed by a relatively stable pattern up to 900 kHz. The loss tangent value obtained has a value <0.5, which means that the addition of Cdots has an effect on reducing the energy loss stored in Fe3O4. Based on this, Fe3O4/Cdots material can be used as a good dielectric material. Keywords: Dielectric material- Fe3O4/Cdots- Green synthesis- Magnetic- Nanoparticles Share Link | Plain Format | Corresponding Author (Mareta Fidya Latifa)

57	Material Physics	ABS-108
The Best Synthesis Route of Selenium Nanowires Determined by Raman Spectroscopy Rachman Shaf (a), Fainan Failamani (b), Bambang Prijamboedi (b), Agustinus Agung Nugroho (b) a) Physics Graduate Program, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Jl Ganesha 10 Bandung 40132, Indonesia b) Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl Ganesha 10 Bandung 40132, Indonesia Abstract The fascinating application of Selenium nanowires as a one-dimensional template of devices such as thermoelectric, piezoelectric, photoconductive, and semiconductor has been continuously developed. The synthesis of Selenium nanowires by facile template-free solution method strongly depends on the pH concentration and its heating condition. To obtain those optimum conditions with less time synthesis process, Raman spectroscopy was utilized to observe the selenium structure in the liquid solution. It is shown that the best synthesis route of Selenium nanowire is characterized by the intensity of trigonal structure at 237cm-1 and 139cm-1 in the solid form, and the disappearance of amorphous and monoclinic structure at ~260cm-1 and ~250cm-1, respectively, in its liquid solution. These spectra are obtained in the Selenium solution with a pH of 9 at 850C for 210 minutes. Keywords: Nanowires- Selenium nanowires- Raman spectra Share Link | Plain Format | Corresponding Author (Rachman Shaf)

58	Material Physics	ABS-109
Solvatochromic Behavior Of Solid-State Nitrogen-Doped Carbon Nanoparticles: Initial Study Rusdia Shaleha Sugiana(a), Reza Umami(b), Fitri Aulia Permatasari(b), Bebeh Wahid Nuryadin (c*) a) Research Center for Nanoscience and Nanotechnology, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung, West Java 40132, Indonesia. b) Department of Physics, Faculty Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung, West Java 40132, Indonesia. c) Department of Physics, UIN Sunan Gunung Djati Bandung, Jl. A.H. Nasution No.105, Bandung, West Java 40614, Indonesia. *bebehwahid102[at]uinsgd.ac.id Abstract Carbon nanoparticles (CNPs) have garnered significant attention among researchers due to their cost-effectiveness and tunable properties, rendering them applicable in a wide array of fields, including biomedicine, optoelectronics, catalysis, and sensing. The solvatochromic effect denotes the phenomenon of a compound exhibiting a color change or a shift in its photoluminescence spectrum. In this study, we investigated the solvatochromic behavior of CNPs doped Nitrogen synthesized through the solid-state route using citric acid and urea, dissolved in solvents with varying polarity indices. Significant differences in emission were analyzed using photoluminescence (PL) spectrometer. The result exhibit the emission shifting towards longer wavelengths (red region) as the solvent^s polarity index increased. This study of solvatochromic behavior in CNPs holds substantial significance for further research into their application as sensors. Keywords: Carbon Nanoparticles, Solvatochromics, Flourescence, Microwave. Share Link | Plain Format | Corresponding Author (Bebeh Wahid Nuryadin)

59	Material Physics	ABS-112
Facile Synthesis of Nanocomposite ZnO and Red betel (Piper crocatum Ruiz & Pav) Salma Aridha Muflihah (a), Akfiny Hasdi Aimon (a*), Euis Sustini (a), Ferry Iskandar (a), Mikrajuddin Abdullah (a) a) Department of Physics, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132, Indonesia aridha.salma[at]gmail.com Abstract Green synthesis of zinc oxide nanoparticles is one of the most widely conducted research nowadays due to its advantages, which are environmentally friendly and simple. Red betel was chosen because of their abundance of phytochemicals which are potential to be bioreductors dan capping agents and their abundant availability in Indonesia. In this study, experiments were carried out with the aim of studying the role red betel in green synthesis and the characteristics of the zinc oxide nanoparticles it produced. The obtained powder was characterized with Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy, and X-Ray Diffraction. The results showed that the obtained sample was ZnO NPs with uneven surfaces and diameter < 100 nm. Keywords: green synthesis, nanocomposite, red betel, ZnO Share Link | Plain Format | Corresponding Author (Akfiny Hasdi Aimon)

60	Material Physics	ABS-114
Evaluation of Neural Network Architectures for Predicting Material Elastic Properties Andi M. N. F. Syamsul (a*), Agoes Soehianie (a), Abdul M. T. Pradipto (a) a) Physics Study Program, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jalan Ganesha 10, Bandung 40132, Indonesia. *andimuhammad164[at]gmail.com Abstract This study evaluated various neural network architectures for predicting material properties from a dataset. Sequential models with varying dense layers (1-3) and neurons per layer (32-112 in 16 steps) were constructed in TensorFlow. The models were trained for 10 epochs on datasets representing material properties, with 80% for training and 20% for validation. Training was performed to minimize mean absolute error loss using the Adam optimizer. Models with more dense layers exhibited lower validation losses, indicating superior predictive ability to capture complex relationships in the data. The number of neurons also impacted model performance, with larger sizes tending to yield lower losses. The key findings showed that adequate hidden layers and neuron counts allowed the models to better learn representations and discriminate patterns needed to accurately predict elasticity and other material properties. This provided guidance on designing optimal neural network architectures for predicting material properties and informed new model designs for enhanced materials simulations. Keywords: Elastic properties- Neural network architecture- Material property prediction Share Link | Plain Format | Corresponding Author (Andi Muhammad Nur Fitrah Syamsul)

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