This study investigates the effect of sugarcane bagasse particle size on the physical and mechanical properties of polypropylene (PP)-based biocomposites. XRF data show that sugarcane bagasse contains potassium (42.4 wt.% or 36.0 wt.% K₂O) and calcium (25.3 wt.% or 23.7 wt.% CaO). Biocomposites were prepared via extrusion and hot pressing at 160 °C and 5 tons using varying particle sizes (20–60 mesh) and compositions (30/70, 35/65, and 40/60 wt.% bagasse/PP). Results show that finer particles (60 mesh) significantly improve composite performance, achieving the highest density (0.65 g/cm³ at 30/70), lowest porosity (≈3–4%), and reduced thickness swelling (≈1.1–1.4%). Mechanical properties also improved, with the highest modulus of rupture reaching ~112 kgf/cm² and flexural modulus peaking at ~19–20 × 10³ kgf/cm², particularly at optimal particle sizes around 50–60 mesh. On the contrary, the use of larger particles (20 mesh) caused increased porosity (approximately up to 13-14%) but lower mechanical strength (80-99 kgf/cm²). Overall, this research has proven that decreasing the filler particle size leads to improved performance of biocomposites due to higher interfacial bonding, higher density, and stress distribution efficiency.
Abstract. This study aims to investigate the potential of durian husk fiber (Durio zibethinus) as the base material for environmentally friendly acoustic panels. The samples were prepared as composites with a fixed composition ratio of durian husk fiber and epoxy resin at 2:1, and with varying thicknesses of 1 cm, 2 cm, 3 cm, and 4 cm. The sound absorption coefficient was measured using the impedance tube method based on ISO 10534-2 in the frequency range of 200–1600 Hz. The results showed that all samples demonstrated good acoustic performance. The 3 cm thick sample provided the best performance with the highest absorption coefficient value of 0.98 at a frequency of 1600 Hz. Increasing the thickness to 4 cm reduced the material's acoustic performance, indicating an optimal thickness limit for sound absorption. This study indicates that durian husk fiber has high potential as an alternative acoustic material that is effective and sustainable, especially for absorbing noise in mid to high frequency ranges.
Water rockets provide a simple yet effective physics experiment integrating mechanics, fluid dynamics, and kinematics. Their performance is influenced by initial air pressure and water volume fraction, which can be quantitatively analyzed using numerical simulation. This study investigates the effects of varying pressure (300–500 kPa) and water volume fraction (f = 0.10–0.60) on thrust profiles and maximum altitude, with analysis covering four distinct phases. The method involves formulating nonlinear differential models for each phase, followed by numerical simulations using the fourth order Runge Kutta (RK4) method with an optimized time step (Δt = 0.001 s) to ensure convergence and computational efficiency. Results show that higher pressures increase peak thrust and maximum altitude, but shorten the duration of water thrust. An optimal water volume fraction of f ≈ 0.20–0.30 provides a balance between thrust intensity and duration to achieve maximum altitude. Further experiments with variations in bottle structure and aerodynamic parameters are recommended.
The horizontal gradient method is a widely used qualitative approach for enhancing the interpretation of gravity anomaly data. This method is particularly effective in delineating lithological boundaries between rock units with contrasting densities, especially where contacts are horizontally aligned. Horizontal gradient calculations are performed by partially differentiating gravity data with respect to its horizontal position. This method was applied to gravity data of Weh Island, the westernmost part of Indonesia, to delineate fault zones and lithological boundaries in the region. The results of the study show that this method can effectively identify rock formations on Weh Island, such as the boundary between coral reef limestone and pyroclastic flow units, as well as tuff sandstone areas and surrounding rocks, including volcanic kulam units and volcanic pumice rocks. Applying the horizontal gradient method to gravity data on Weh Island produced maps that clearly outline rock formations. Combining these with geological maps shows a northwest–southeast trend aligned with the main strike of the Seulimuem Fault, which crosses the island. The results from analyzing horizontal derivatives offer key insights for studies of lithology, faulting, and subsurface layers in complex geological regions like Weh Island.
In molecular radiotherapy, dosimetry accuracy is highly dependent on the calculation of the Time-Integrated Activity Coefficient (TIAC), as recommended by the Medical Internal Radiation Dose (MIRD). The accuracy of the TIAC value is obtained using data fitting in the form of a mathematical function model. The fitting function represents the pharmacokinetic parameters of the radiopharmaceutical in the form of radiopharmaceutical activity, physical decay, and biological decay. The aim of this study is to estimate parameters of activity and biological decay rate constants based on biokinetic data (activity fraction) against time. Fitting of biokinetic data was performed using the sum of exponential (SoE) monoexponential function with a MATLAB® 2020b simulation to estimate the activity parameter (Ao) and the biological decay rate constant parameter (λ₀) of the population. A simplified linearity regression test was also performed to estimate the biological decay rate constant parameter (λ) individuallly for each patient. The results of the fitting obtained the values of Ao and λ₀ for each organ as follows:liver (Ao= 0.290 and λ₀= 0.02 h-1), right parotid (Ao= 0.05 and λ₀= 0.02 h-1), left parotid (Ao= 0.05 and λ₀= 0.02 h-1), right kidney (Ao= 0.45 and λ₀= 0.02 h-1), left kidney (Ao= 0.39 and λ₀= 0.02 h-1) and bladder (Ao= 0.09 and λ₀= 0.03 h-1). From the linear regression test, the λ values from the fastest to the latest decay range were obtained for the organs: right kidney (0.015-0.036 h-1), liver (0.009-0.032 h-1), left kidney (0.017-0.032 h-1), right parotid gland (0.014-0.035 h-1), left parotid gland (0.014-0.034 h-1) and bladder (0.010-0.047 h-1). Based on this result, it can be concluded that using a monoexponential function to fit and perform a simple linear regression test is effective in estimating parameters in both the population and individuals.
MAPbI3 perovskite material is a leading candidate for third-generation solar cells because it has high absorbance and a suitable band gap. However, efficiency and stability remain major issues. In this study, phenethylammonium iodide (PEAI) doping will be performed on the optical properties and energy gap of MAPbI3 perovskite material. The Perovskit layers were fabricated by two-step spin coating method which is known to be effective in producing controlled and homogeneous thin layers. Characterization of the coating was carried out by UV-Vis spectroscopy to obtain absorbance spectrum data, and then analyzed using the Tauc Plot method to obtain the energy Gap value. The results show that the addition of PEAI can increase the intensity of absorption in the visible light region and cause a blue shift at the absorption edge. The energy Gap value increased after doping from 1.61 eV in the pure sample without doping to 1.68 eV for the highest doping concentration. This indicates that PEAI doping plays a role in modifying the energy band structure and improving the optical characteristics of Perovskit layers. This study shows that PEAI doping is a promising approach to improving the optical performance of perovskite layers in solar cell applications.
This article presents a comprehensive review of recent advancements in perovskite-based solar cells, focusing on material structures, optical properties, and electronic characteristics. The objective is to identify the potential and technical challenges affecting device performance and long-term stability. A systematic literature study was conducted using peer-reviewed articles published between 2021 and 2025, retrieved from international databased index. The review highlights that variations in perovskite composition, including all-inorganic and hybrid types, significantly affect optical absorption and photoluminescence, as well as device stability. Furthermore, fabrication methods such as spin coating, vapor deposition, and blade coating have a direct impact on power conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF). Blade coating yielded the highest reported PCE of 27.8% and Voc up to 1.9 V, while vapor deposition achieved Jsc up to 25.7 mA/cm² and FF of 76.8%. This review concludes that the advancement of perovskite solar cells should focus on integrated strategies in material design and deposition techniques to ensure high efficiency and long-term operational reliability.
Abstract. Diagnostic and interventional radiology X-ray machines used by health facilities are required to undergo periodic testing before being put into service. This study was conducted to analyze the appropriateness of a fluoroscopic X-ray machine at a type A hospital in Banda Aceh. Direct quality assurance measurements were performed using a PMMA-type phantom, a fluoroscopic X-ray machine (SIEMENS AGILE MAX), X-ray multimeters, and aluminum filters. The BAPETEN standard No. 2 in 2018 was used as a reference. Based on the measurement analysis results, the voltage accuracy measurement is deviated by 0.13–0.3% higher from the voltage setting; however, it remained within the minimum threshold by BAPETEN standard. The radiation beam quality value (HVL) is relatively low compared to the standard minimum value and remained below the threshold. The typical dose rate has met the standard, and the maximum dose rate in the air is also below the set standard. However, the maximum dose rate in the air was observed to be 60 mGy/min at a voltage of 100 kVp.
This research aims to analyze the high level thinking abilities (HOTS) of class VII students on temperature and heat subject seen from the learning environment. The HOTS measured includes three aspects: analysis (C4), evaluation (C5), and creation (C6). This research also discusses how specific and general learning environments influence student understanding. This type of research is descriptive qualitative, involving 60 students of SMP Negeri 1 Lhokseumawe, consisting of 30 students from special learning environments and 30 students from general learning environments. Data was obtained through a HOTS-based 9-question written test, interviews and observations. The results show that students from special learning environments have better HOTS abilities, with the highest score on creation (C6) of 45.60%. The low ability of students from general learning environments is due to a lack of support, such as additional tutoring. Schools are advised to provide support programs to improve students' abilities
Hydroxyapatite is one of the candidate medical materials as bone and tooth replacement (implant). In this study, the synthesis and characterisation of hydroxyapatite from clamshells (Anadara granosa) with variations in sintering resistance time were successfully carried out. The purpose of this research is to synthesise hydroxyapatite from clamshells and find out how the effect of variations in sintering resistance time on crystal size and degree of crystallinity of hydroxyapatite. The source of calcium oxide (CaO) used in the synthesis of hydroxyapatite comes from blood cockle shells powder (Anadara granosa), after first the blood cockle shells is calcined at 1000⁰C with a holding time of 5 hours. The hydroxyapatite synthesis process uses a solid state reaction method with a sintering temperature of 900⁰C with a variation of holding time of 2 hours, 4 hours and 6 hours to determine the formation of hydroxyapatite. This process has successfully formed calcium oxide (CaO) compounds based on characterisation with XRF (X-Ray Fluorosence) and XRD (X-Ray Diffractometer). Based on the XRD test results, it is known that hydroxyapatite has been successfully synthesized from clamshells. The characterisation results show that the variation of sintering resistance time affects the degree of crystallinity and crystal size of hydroxyapatite, which are 45.70% - 68.49% and 49.9nm - 55.37 nm, respectively.
This study aims to determine the acoustic properties of gypsum panel, gypsum-ijuk panel, ijuk-gypsum panel, foam concrete panel, and foam concrete-ijuk panel. The size of panel was 1 m x 1 m with a thickness of 0.02 - 0.03 m. The measurement of the sound absorption coefficient was carried out using the reverberation chamber method (ISO 354-1985) for the frequency range of 125 – 4000 Hz. The results showed that the sound absorption coefficient fluctuated with frequency. Gypsum panel has the highest sound absorption coefficient of 0.42 at 125 Hz and the lowest 0.05 at 400 Hz. Ijuk panel has the highest sound absorption coefficient at 2000 Hz which is 0.97 and the lowest at 200 Hz which is 0.09. The sound absorption coefficient of the combined panel of ijuk with gypsum (ijuk above and gypsum below) is 0.85 at 2500 Hz and 0.06 at 315 Hz. Gypsum and ijuk composite panels (gypsum above and ijuk below) have the highest sound absorption coefficient of 0.93 at 125 Hz and 0.09 at 315 Hz. Foam concrete panel has the highest sound absorption coefficient at 160 Hz with a value of 0.91 and the lowest at a frequency of 315 Hz with a value of 0.08. Foam concrete panel combined with palm oil (foam concrete on top and ijuk below), the sound absorption coefficient is 0.86 at 800 Hz and 0.15 at 500 Hz. The results of this study show that the sound absorption coefficient can be improved by combining a number of materials. Composite panels of foam concrete-ijuk and gypsum-ijuk have the potential to be applied for sound absorber materials.
Students' skills in solving physics problems with a correct and in-depth understanding of concepts are skills that they should have in facing life in the 21st Century. One way to identify students who can solve problems is by looking at their ability to represent physics problems in suitable formats. different things which are called multiple representations. This research aims to analyze students' abilities in solving physics problems based on multi-representational aspects, in this case, what is looked at are aspects of verbal, visual, symbolic, and mathematical representation. The data collection technique used was a test with test questions in the form of essays with cognitive levels C3, C4, and C5. The research results show that the overall average score for students' ability to solve problems is 51.7, with a percentage of verbal representation of 73.13%, visual representation of 57.25%, symbol representation of 63.64%, and mathematical representation of 65. 45%. Thus, it can be concluded that overall students' physics problem-solving abilities are in the medium category, abilities based on verbal representation aspects are in the high category, visual representations are in the medium category, symbol representations are in the medium category, and mathematical aspects are in the high category.
CT-Scan examination in medical diagnostics produces higher radiation compared to conventional X-Ray, especially for certain clinical conditions that require additional contrast media that contribute to higher radiation energy absorbed by the tissue. Contrast media are generally iodine-based which has a high density and absorbs more X-rays, thus increasing the HU value. This study aims to determine the effect of contrast media on Hounsfield Unit (HU), Computed Tomography Dose Index (CTDI), and Dose Length Product (DLP) values to support the determination of Typical Dose Value (NDT). This study uses an experimental quantitative approach by comparing CT-Scan examination data before and after administration of contrast media in a number of patients. HU values are measured in the main blood vessels, while CTDI and DLP were obtained directly from the CT Scanner console. The study sample consisted of 30 abdominal patients and 26 head patients for NDT analysis, including 10 abdominal patients and 10 head patients each used to detect changes in HU values. The results show that the administration of contrast media in CT examinations of the abdomen and head causes a significant increase in Hounsfield Unit (HU) values, namely from 43,53 to 290,58 for the abdomen and from 35,98 to 67,65 for the head. In addition, there is an increase in the Typical Dose Value (NDT) after the use of contrast. The recorded radiation dose parameters are of 5,05 mGy and DLP of 118,13 mGy cm for the abdomen, and of 49,35 mGy and DLP of 1108,30 mGy cm for the head, all of which remain below the Dose Reference Level (DRL) limit. These results confirm that contrast media not only improve image quality by increasing Hounsfield Units (HU), but also affect the amount of radiation dose received by patients. Therefore, optimal scanning parameter settings are needed to achieve a balance between diagnostic image quality and radiation safety.
The iron sand found on the coast of Aceh has the potential to be developed as a magnetite material. This study aims to analyze the Fe concentration in iron sand and investigate the effect of varying stirring speeds during magnetite synthesis via coprecipitation on the resulting band gap energy. Iron sand was randomly collected from Anoi Itam Beach, Sabang, then separated from non-magnetic material using a bar magnet, washed with distilled water, and ground into a fine powder. The synthesis was carried out using the co-precipitation method with stirring speeds of 800, 900, and 1000 rpm. The Fe content was analyzed using Atomic Absorption Spectroscopy (AAS) in three stages: natural iron sand, prepared iron sand, and dissolved iron sand. After magnetite formation, the energy gap was determined through optical absorption analysis using a UV-Vis spectrophotometer with the Tauc plot approach. AAS results showed an increase in Fe concentration after synthesis after the dissolution of iron sand, while the increase in stirring speed affected changes in the energy gap. This change in the energy gap has implications for the electronic and optical properties of magnetite. It can be concluded that higher stirring speeds result in an increased energy gap, indicating the presence of other iron oxide phases or size quantization effects occurring in the magnetite.
Machine learning has rapidly emerged as an effective system in various fields, including materials science, due to its ability to efficiently uncover complex patterns from big data. This research aims to develop a machine learning-based semiconductor electrical conductivity prediction system integrated with solid state physics theory. In the context of electronic material technology development, the ability to predict the electrical properties of materials before the synthesis process is crucial for improving efficiency and accuracy in material design. This study employs a qualitative descriptive method to create a machine learning-based system and qualitatively describe the research results. The dataset is obtained from various literature and previous experiments, with physical parameters such as crystal structure, band gap, and density. The machine learning model used is the random forest algorithm. Evaluation results show that the system can classify materials based on their electrical conductivity properties with high accuracy. Materials such as GaAs, Ge, and Si are identified as potential candidates for electronic device design. The integration of solid-state physics theory into this system enhances the physical and statistical validity of predictions. This research demonstrates that a machine learning approach based on physical principles can be an effective solution for future semiconductor material engineering.
The limited availability of physics teaching materials in schools leads to a lack of engaging learning resources, making the learning process less effective, with some students struggling to stay focused during lessons. As a solution, the researcher developed a Web Quiz Kahoot-based e-module, specifically on the topic of work and energy. This study aims to develop, evaluate the feasibility, and assess the practicality of the Web Quiz Kahoot-based e-module in physics learning. The type of research conducted was Research and Development, utilizing instruments such as validation sheets by subject matter experts, media experts, and practicality questionnaires for students. The development of the e-module employed the ADDIE model (analysis, design, development, implementation, and evaluation). The validation results from material experts indicate a feasibility level of 86.5%, categorized as highly feasible, while validation from media experts obtained a percentage of 97.8%, also categorized as highly feasible. Overall, the average feasibility score reached 93.75%, categorized as highly feasible. The practicality questionnaire results from students showed a percentage of 87%, categorized as highly practical. Based on these findings, it can be concluded that the Web Quiz Kahoot-based e-module is highly feasible and practical for use. This research showed that the Web Quiz Kahoot-based e-module could be used flexibly in both online and face-to-face learning. Teachers could easily access and adapt the material, while students could use it anytime as a self-learning resource.
Peningkatan jumlah penduduk di kota turut mendorong kebutuhan barang dan jasa, termasuk layanan laundry di kawasan pemukiman. Usaha laundry banyak yang belum dilengkapi dengan fasilitas pengolahan limbah, sehingga limbahnya langsung dibuang ke saluran udara dan berpotensi mencemari lingkungan. Penelitian ini bertujuan mengembangkan sistem filtrasi up flow dengan tambahan disinfeksi UV dan cartridge filter untuk pengolahan limbah laundry yang lebih efisien. Limbah laundry mengandung bahan berbahaya, seperti detergen dan zat aktif permukaan, yang dapat berdampak buruk pada lingkungan jika tidak diolah. Sistem ini menggunakan media filter seperti pasir silika, karbon aktif, zeolit, kerikil, dan sabut untuk mengurangi kekeruhan serta menghilangkan kontaminan. Sistem ini juga dilengkapi dengan sensor kekeruhan Turbidity DFROBOT SEN0189 yang menampilkan hasil pengukuran kekeruhan di layar LCD untuk memantau kualitas udara secara langsung. Metode eksperimen yang diterapkan meliputi perakitan alat, pengujian sensor, dan evaluasi kinerja sistem filtrasi. Kalibrasi sensor dengan larutan kopi menunjukkan korelasi tinggi (R² = 0,9098) antara tegangan sensor dan nilai kekeruhan. Hasil uji filtrasi menunjukkan sistem ini efektif dalam menurunkan kekeruhan dan parameter seperti Nitrat, Kromium Heksavalen, TDS, pH, Besi, dan Mangan hingga sesuai standar baku mutu limbah. Studi ini menunjukkan bahwa sistem filtrasi yang dikembangkan memiliki potensi sebagai solusi pengolahan limbah laundry yang lebih ramah lingkungan.
Kabupaten Lebong merupahkan salah satu daerah rawan gempa bumi, karena terdapat Sesar Sumatra dan Sesar Pelabai yang melintas dikawasan ini. Penelitian ini bertujuan untuk menganalisis potensi bahaya gempa bumi berdasarkan hasil uji mikrotremor menggunakan metode Horizontal to Vertikal Spectral Ratio (HVSR). Pengukuran dilakukan sebanyak 106 titik yang tersebar di Kecamatan Amin, Bingin Kuningan, Lebong Atas, Lebong Sakti, Lebong Selatan, Lebong Utara, Pinang Belapis, Rimbo Pengadang, Topos, Pelabai dan Uran Jaya. Parameter yang di analisis meliputi faktor amplifikasi ( A 0 ), frekuensi dominan ( f 0 ), periode dominan ( T 0 ) dan indeks kerentanan seismik ( K g ). Hasil analisis menunjukkan bahwa indeks kerentanan seismik dengan kategori tertinggi dengan rentang nilai 5 sampai dengan lebih dari 10 berada di Kecamatan Pinang Belapis, Pelabai, Lebong Selatan, Topos, Rimpo Pegadang, dan Uram Jaya dimana pada kecamatan tersebut berjenis tanah sangat padat dan batuan lunak serta tanah lempung tebal lunak. Bangunan yang berpotensi mengalami resonansi pada saat gempa terjadi adalah bangunan berlantai 1 sampai dengan 4. Hal ini disebabkan karena frekuensi alami bangunan yang sama dengan frekuensi getaran yang dialami oleh tanah.
Abstrak. Wilayah Kampung Melayu memiliki kondisi litologi batuan yang tersusun atas formasi undak alluvium (Qat) yang terdiri dari pasir, lempung, lanau, dan kerikil yang bersifat lepas sehingga dapat memicu terjadinya fenomena likuifaksi apabila terjadi gempa bumi. Penelitian ini bertujuan untuk mengetahui potensi likuifaksi berdasarkan nilai resisitivitas litologi batuan bawah permukaan bumi dan kedalaman muka air tanah (watertable) pada 40 titik Sounding di daerah penelitian dengan menggunakan metode Vertical Electrical Sounding (VES) konfigurasi Schlumberger. Hasil penelitian menunjukkan bahwa lapisan bawah permukaan di Kecamatan Kampung Melayu terdiri dari batuan alluvium, mencakup lempung, kerikil, pasir, napal, air payau, dan air tanah, dengan nilai resistivitas berkisar antara 0 hingga 508 Ω.m. Keberadaan formasi alluvium ini menjadi ancaman yang serius pada saat terjadi gempa bumi yang dapat bepotensi terjadinya likuifaksi. Kedalaman muka air tanah (watertable) di wilayah ini relatif dangkal, berkisar antara 1 hingga 25 meter, dengan nilai resistivitas antara 5,1 hingga 40 Ω.m. Adanya zona jenuh air yang dangkal dan struktur batuan alluvium menunjukkan potensi resiko likuifaksi. Abstract. The Kampung Melayu area has rock lithology conditions which are composed of alluvium step formations (Qat) consisting of loose sand, clay, silt and gravel which can trigger liquefaction phenomena when an earthquake occurs. This research aims to determine the liquefaction potential based on the lithological resistivity values of the earth's subsurface rocks and the depth of the groundwater table (watertable) at 40 sounding points in the research area using the Schlumberger configuration Vertical Electrical Sounding (VES) method. The research results show that the subsurface layer in Kampung Melayu District consists of alluvium rock, including clay, gravel, sand, marl, brackish water and groundwater, with resistivity values ranging from 0 to 508 Ω.m. The existence of this alluvium formation poses a serious threat during an earthquake which could potentially cause liquefaction. The depth of the groundwater table (water table) in this area is relatively shallow, ranging from 1 to 25 meters, with resistivity values between 5.1 and 40 Ω.m. The existence of shallow water saturated zones and alluvium rock structures indicate a potential risk of liquefaction.
Ek Leuntie Cave, in the southern city of Banda Aceh, Aceh Province, is recognized as an educational media based on geopark sites because it holds a 7400-year paleotsunami track record. As a karst area, Ek Leuntie Cave is vulnerable to the impact of geological disasters such as earthquakes, sinkholes and subsidence. As an effort to reduce the negative impact of geological disasters, geophysical studies have been applied in the Ek Leuntie Cave Karst area. The study aims to identify the subsurface geological structure of the Karst area. The identification was carried out using the Electrical Resistivity Tomography (ERT) method of Wenner-Schlumberger configuration applied to two measurement trajectories that have South-North and West-East directions in front of the Ek Leuntie Cave door. ERT data acquisition results were then modeled in inversion using Res2Dinv software to produce a 2D model of the subsurface geological structure of the Ek Leuntie Cave karst area based on variations in rock resistivity values. Interpretation of subsurface geological structure modeling is validated with shallow drilling data (Hand Auger). The inversion modeling results show that the rock resistivity value in the Ek Leuntie Cave area reaches a depth of 30 m which has a resistivity value of 0 - 1000 Ωm. The results of the interpretation of resistivity values and validation of drill data show that the Ek Leuntie Cave area is covered by a layer of sand with fine to coarse texture and the layer below is a layer of limestone at a depth of ± 0.4 meters with a resistivity value of 50 - 250 Ωm. Limestone generally shows porosity with the possibility of caves or pores in the rock formation at Ek Leuntie Cave, making it vulnerable to damage from earthquakes, landslides, and subsidence. The results of the study are expected to provide updated information in efforts to develop the Ek Leuntie Cave geopark area.
