bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication and Evaluation of an Electromagnetic Shielding Material Made of Randomly Chopped Tape Carbon Fiber/Polyamide 6 Composites
Authors: Aripin A B , Sasongko N A , Purqon A , Hayakawa K 
Published: October 2024

Abstract
Environmental pollution generated by electromagnetic wave radiation has significantly increased including in automotive applications. Thus, material technology, including polymer composite, has attracted a reduction of the negative effect of electromagnetic radiation. In this study, carbon fiber reinforced polyamide thermoplastic (PA-6/CF) made of carbon fiber with polyamide 6 tape, in the shape of a half-box, was produced using the hot compression method with different tape-length, and then the electrical conductivity and electromagnetic shielding performance were evaluated. The electrical conductivity was obtained from the resistivity measured by using a digital multimeter. Whilst the effectiveness of electromagnetic interference shielding (EMI-SE) was investigated using two methods, calculation, and actual measurement. The result shows that there is a different electrical conductivity between base and slope area of the PA-6/CF box composite. It also was observed that the actual EMI shielding performance shows a corresponding increase with the length of chopped carbon fiber tape and has a higher value compared to the calculated EMI-SE. Then, the highest value obtained for actual EMI-SE was 54 dB for the PA6/CF composite with 20-mm tape length, in the frequency range 0.3 – 1 GHz, and on horizontal antenna polarization. Whereas the composite with 10-mm and 15-mm tape length was the lowest EMI- SE (38 dB) on vertical antenna polarization, in the same frequency range. Furthermore, the microscopy analysis depicted that there are more voids exist in the slope area compared with the base area of the PA-6/CF composites. Finally, the molded PA-6/CF composites can be used as the battery enclosures of electrical vehicles in automobiles.
Influence of Sulfur Addition on The Physical and Photocatalytic Properties Biosynthesized Se-doped ZnO Nanoparticles
Authors: Rini A S , Sitorus A H , Rati Y , Simatupang M P , Taer E , Usman Z , Jasril  
Published: October 2024

Abstract
The objective of this study was to investigate the influence of Sulfur (S) addition to selenium-doped zinc oxide (Se-ZnO) nanoparticles on their physical properties and photocatalytic activity. S,Se-ZnO sample was prepared by adding 1wt% sulfur onto 4%Se-ZnO nanoparticles. In the synthesis procedure, microwave irradiation was used as heating power and matoa leaf extract was used as a bioreductor. The nanoparticles were characterized using UV-Vis Spectroscopy, X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The calculated band gap energies of Se-ZnO and 1% S,Se-ZnO are 2.38 eV and 2.62 eV, respectively. Both samples exhibit a hexagonal wurtzite structure. FESEM image of addition S reveals flower petal flake formations and decrease particle size of 187 nm. The photocatalytic activity of nanoparticles was evaluated through 4-nitrophenol (4-NP) degradation under UV-C irradiation. 1% S,Se-ZnO exhibits high photocatalytic efficiency compared to Se-ZnO, with a degradation percentage of 85.09% after 60 min and a reaction rate of -0.0315 min−1. Based on these results, the addition of S on Se-ZnO biosynthesized shows improve physical properties and efficient photocatalytic materials for pollutant removal.
Examination of the Effectiveness of Orange Peel Pectin and Chitosan as Edible Coating Materials for Tomato Fruit (Lycopersicum esculentum Mill.)
Authors: Sembiring Emita Br. , Frida Erna , Sitorus Zuriah , Sembiring Timbangan 
Published: October 2024

Abstract
This study investigates the effects of varying pectin concentrations in edible coatings on tomatoes, focusing on viscosity, surface morphology, weight loss, and structural analysis. The viscosity of pectin-based solutions increased with higher concentrations, ranging from 451.5 cP for 1.0 g to 535.2 cP for 2.5 g of pectin. A coating with 2 wt.% pectin and chitosan showed a uniform dispersion of curcumin nanoparticles and maintained a compact structure, while higher concentrations led to increased porosity and roughness. The coating significantly reduced weight loss, with only a 7.3% reduction after 21 days in the 2 wt.% pectin sample, compared to 10.95% in untreated tomatoes. FTIR analysis revealed functional groups that enhance the coating’s stability and barrier properties. The results indicate that optimizing pectin concentration is key to achieving a balance between coating effectiveness and ease of application, ultimately extending the shelf life of tomatoes.
Characterization of Adsorbents Based on Pahae Natural Zeolite and Candlenut Shell Activated Carbon for Peat Water Purification
Authors: Susilawati  , Frida E , Andriayani  , Sinuhaji P , Sebayang P , Padang S T , Irma M 
Published: October 2024

Abstract
The importance of developing effective adsorbents for environmental applications cannot be overstated, particularly in the context of water and wastewater treatment. Previous research has extensively explored various natural and synthetic materials for their adsorption capabilities. Pahae natural zeolite, a naturally occurring aluminosilicate mineral, is known for its excellent ion-exchange properties and high surface area, making it a promising candidate for pollutant removal. Similarly, activated carbon derived from agricultural by-products, such as candlenut shells, has been recognized for its superior adsorption characteristics due to its porous structure and large surface area. This study focuses on the synthesis and characterization of an innovative adsorbent combining Pahae natural zeolite and candlenut shell activated carbon. The goal is to harness the synergistic effects of both materials to enhance the adsorbent’s performance. By investigating various compositions of these two materials, the research aims to optimize the adsorbent’s physical properties, particularly porosity and water absorption capacity. The findings reveal that a composition of 75% Pahae natural zeolite and 25% candlenut shell activated carbon yields optimal results, with a porosity of 57.26% and a water absorption capacity of 56.70%. These results underscore the potential of this composite adsorbent in improving water treatment processes and contribute to the growing body of knowledge on sustainable and efficient adsorbent materials.
Differences Photopolymerizations and Characterizations of Monomers Liquid Crystal between Mesogen Reactive RM 257 and Cholesteryl Acrylate using method of UV Curing
Authors: Afrizal  , Budi Setia , Riswoko Asep , Lestari Fuji , Ningsih Selvia 
Published: October 2024

Abstract
Mesogen reactive RM257 and cholesteryl acrylate are two types of liquid crystal with the characteristic property of possesing polymerizable groups. Cholesteryl acrylate has interesting properties that can form a helical spiral structure. Previous research in maintaining the helical structure has not been maximized. In this study, we will explain how the UV curing process is a way to fix the helical structure. Monomer phase of cholesteryl acrylate only appears at mesophase temperature, in order to maintain the helical structure of the cholesterl acrylic compound is polymerized. Mesogen reactive RM257 is monomer liquid crystal that acrylate functions as back bone polymer chain. Cholesteryl acrylate and RM257 each monomers is polymerized using UV light with 55 watt of wavelength which has 365 nm. The polymerization process produces a new functional group formed by C-O esters at wave numbers 1047 cm−1 and 1055 cm−1. XRD diffraction pattern showed peaks at 2θ in 7.5°,15°, and 20°. Photo SEM image showed crosslinked morphology structure. Based on the results of this study, it is hoped that the polymer RM257 and acrylate coliform can be smart materials for sensor applications and further technological material composites.
Incorporation of Gold Nanoparticle into ZnO Electron Transport Layer to Improve Performance of Hybrid Bulk Heterojunction Solar Cell
Authors: Merdeka Muhammad Cikal , Syarif Nur Fadhilah , Hidayat Rahmat , Wulandari Priastuti 
Published: October 2024

Abstract
We have investigated the effect of localized surface plasmon resonance (LSPR) from gold nanoparticles incorporated into the electron transport layer (ETL) of zinc oxide (ZnO) on charge carrier transport in order to improve the performance of inverted hybrid bulk-heterojunction solar cells. Synthesis of gold nanoparticles capped by 3-mercaptopropionic acid (AuMPA) and oleylamine (AuOA) was carried out by use of the reduction method and the fabrication of solar cell device with the configuration of ITO/ZnO:AuNPs/P3HT:PCBM/PEDOT:PSS/Ag was done by spin coating and thermal evaporation techniques. The absorbance spectra show a plasmonic peak of AuMPA in solution at 521 nm, while AuOA has a plasmonic peak at 531 nm, with both solutions showing a red-wine color. In our investigation, the incorporation of AuMPA about 2.65wt% or AuOA about 3.5 wt% in the ZnAc solution is quite stable. With the addition of 1.77 wt% AuMPA, the fabricated devices show a significant improvement at short circuit condition (JSC) from 46.67 mA/cm2 to 83.11 mA/cm2, resulting in an increase in power conversion efficiency (PCE) from 5.64% to 9.00% under the illumination of 100 mW/cm2 simulated solar irradiation. While the AuOA addition of 2.65 wt%, the JSC increased from 22.67 mA/cm2 to 44.12 mA/cm2 along with an improvement of PCE from 2.71% to 5.32%. The experiment results suggest that the electron mobility or charge carrier transport to the indium tin oxide (ITO) cathode is improved by the local electric field enhancement around the zinc oxide (ZnO) electron transport layer due to the effect of gold nanoparticles (AuNPs).
Effect of Atomic Vacancy Defect in h – BN Monolayer on Electronic Properties: A DFT Study
Authors: Nenohai A J W T , Santana F M , Arifin R , Asih R , Darminto  
Published: October 2024

Abstract
h-BN is a 2D material which also has considerable development potential in several fields. 2D materials such as h-BN are basically insulating materials but have unique properties and it would be good if they could be developed, especially to meet future energy needs or in the development of electronic devices. Therefore, the properties of h-BN are certainly needed to support this, one of which is the magnetic properties of h-BN. In this research, we modified the h-BN structure by providing defects in the form of vacancy defects by removing atoms in the h-BN layer. We modeled a monolayer h-BN with a supercell size of 4 x 4 x 1, and our calculations were carried out with Quantum ESPRESSO, which is based on density functional theory. The results we obtained showed the emergence of magnetic moment values in h-BN due to defects in the form of atomic vacancies. Furthermore, this research successfully illustrates how vacancy defects in h-BN can modify the band structure, leading to changes in electron behavior around the Fermi energy level.
The Effect of Quenching Process on The Microstructure and Hardness of AISI 4140 Steel
Authors: Basori I , Masitah I , Susetyo F B , Nanto D 
Published: October 2024

Abstract
Steel is a metal that has good strength widely used in industry, both in the construction and automotive fields as a protective material applied to the body of combat vehicles. Combat vehicle body materials must have high strength and hardness to withstand bullet penetration. Meanwhile, some types of steel do not have such strong point to endure impact and bullet penetration, so their strength and hardness need to be increased. One method that can be used to increase the qualities of steel is heat treatment, such as quenching process. In this research, the quenching process was carried out on commercial AISI 4140 steel to increase its hardness. The heat treatment process for AISI 4140 steel begins with an austenization process at a temperature of 850 °C with varying holding times, followed by a quenching stage using SAE 40 oil media. Afterward, the microstructure observation and hardness testing of the test material were carried out using the Optical microscope and Vickers method. The raw material has a hardness value of 215.58 VHN. After the heat treatment process in 30, 60, and 90 minutes was carried out, the hardness value of AISI 4140 steel reached 371.24, 474.48, and 545.5 VHN, respectively. The research results show that the longer the holding time in the quenching process lasts, the more increases the hardness value of the steel will be, which result in microstructure as a dominant martensite phase.
Stimulated Brillouin Scattering Gain of Waveguides Calculated with Acoustic Perturbation Method
Authors: Ramadhan K , Permana D P , Hidayat W , Soehianie A , Marpaung D , Iskandar A A 
Published: October 2024

Abstract
Stimulated Brillouin Scattering (SBS) is a phenomenon of energy transfer from an optical pump beam to longer wavelengths of light through its interaction with the medium via acoustic phonons. Previous studies have reported a calculation of the SBS gain based on the optical force approach, where the gain is not only affected by the classical paradigm of intrinsic material’s nonlinear effects in the form of electrostriction but also due to radiation pressure. In this work, the acoustic perturbation approach is applied in analyzing the optical and mechanical response of the waveguide, wherein calculating the scattering process, the changes of the waveguide structure due to photoelasticity (PE), termed Moving Boundary (MB), are considered. This acoustic perturbation method avoids uncertainties related to optical force contributions. To validate its applicability, the present method is used to calculate the SBS gain of various waveguide structures, namely an unsuspended Silicon nano-waveguide, ridge Lithium Niobate (LiNBO3) nano-waveguide on Sapphire (Al2O3) substrate and buried Arsenic trisulfide (As2S3) in Silicon dioxide (SiO2). The forward and backward SBS gain obtained using the present method of acoustic perturbation are similar to the reported values obtained from other methods of calculation as well as experiments.
Preparation of hydrilla verticillata activated carbon adsorbent for remediation of wastewater containing the active metal chromium
Authors: Tarigan Enda Rasilta , Frida Erna , Humaidi Syahrul , Susilawati  
Published: October 2024

Abstract
This research aims to determine the capacity of Hydrilla Verticillata activated carbon adsorbent in absorbing the heavy metal chromium. The method used in making Hydrilla Verticillata activated carbon is by carbonization at a temperature of 3000C and chemically activated. Activated carbon was contacted with a solution of the heavy metal chromium with a concentration of 100 ppm with contact times of 15, 30, 45, 60, 90 and 120 minutes. The structure of hydrilla verticillata active carbon from the XRD results is graphite and BET BJH characterization data shows that activated carbon has a surface area of 53.143 m2/g, an average pore size of 0.2764 nm and a pore volume of 0.0789 cc/g. The SEM- Edx characterization results show that the size distribution is not homogeneous but forms agglomerations like plate particles consisting of slitted pores. Test results using AAS show that the ability of hydrilla verticillata activated carbon to remediate the heavy metal chromium based on contact time is around 47.35%, 46.77%, 49.08%, 54.85%, 61.30% and 69.69% and the adsorption capacity is around 13.94 mg/g.
The Correlation Between Compressive Strength and The Size of Pore Fly Ash and Perlite Concrete Geopolymer at High Temperature
Authors: Farida F M , Kusumohadi C S , Alanas E , Fikri M F 
Published: October 2024

Abstract
Burned material experiences a decrease in yield strength and elasticity modulus. Fire supervision is required. One of the sustainable material is geopolymer. In this study, fly ash and perlite-based concrete geopolymer have been burned for 900°C for 2 hours. It is followed by Surface Area Analyzer test equipment. The size of pore changes for burned concrete geopolymer. Meanwhile, one of the strength of concrete geopolymer indicator is compressive strength. Both of the results of compressive strength and the pore size are conducted through experimental study. Bet method has been used to measure pore size of it. UTM machine has been used to calculate compressive strength. The surface area analyzer test results show that the addition of perlite to fly ash-based geopolymer concrete will decrease the value of surface area, pore volume, and pore distribution in burned geopolymer concrete, but the addition of perlite to fly ash-based geopolymer concrete will increase the value of pore distribution and decrease the value of surface area and pore volume in unburned geopolymer concrete.
Design of Biomaterial Absorber using coconut shell charcoal for 38 GHz frequency
Authors: Umaisaroh Umaisaroh , Alaydrus Mudrik , Handoko Erfan , Alferinanda Nadio 
Published: October 2024

Abstract
Activated carbon derived from coconut shells has gained significant attention as an effective and sustainable absorber material. The process involves carbonizing coconut shells to create a carbon-rich base, followed by activation through heat and steam, leading to a porous structure with a vast surface area. In this research, coconut shell charcoal is used to make an absorber for microwave application. We used relative permittivity (ε) 3.178, relative permeability, (µ) 1.215 and dielectric loss tangent (σ) 0.0719 to simulate the material based of coconut shell charcoal. We investigate the absorption in terms of design and the size of the proposed absorber in the frequency region of 26.5 GHz to 40 GHz (Ka band). The optimal absorption was achieved with a transmission factor of -29.22 dB and -52.94 dB in both simulation and measurement. The absorption percentage > 99 % for the flat design of the coconut shell charcoal design with the thickness of 16.9 mm.
Fuzzy Logic-Based Feedwater Controller for the Super Fast Reactor
Authors: Sutanto  , Santi Marili , Lestari Anggun Dwi 
Published: October 2024

Abstract
Super fast reactor is a Generation IV reactor with water coolant at supercritical pressure. It has advantages of having high efficiency of about 44%, more economical and excellent safety features. Its last core design which adopted one heating in one coolant cycle, however, results a large density change along the fuel channels. It leads to a sensitive steam temperature change against a change of power which might mismatch with the flow change. The sensitivity should be reduced to maintain the structure integrity of the reactor components. A feedwater controller which based on fuzzy logic was used to reduce the sensitivity. Method of fuzzy-based control is applied. Two signals of the temperature and the power changes were taken as the inputs of the fuzzy controller, and change of the feedwater coolant flow was taken as the control output. Fuzzifications used triangular member functions with Tsukamoto fuzzy model for inferencing process. Two control parameters of member function spread and signal values which lead to fuzzy degree of 1 were optimized so that the criteria of outlet coolant temperature and the stability were fulfilled. Test results of the control system showed that the deviation of the water temperature at outlet side could be kept within the criteria when mismatch change of power and water flow happened. The temperature deviation could be supressed by using the fuzzy-based control.
Calculation on power factor and figure of merit in a single-layer NiBr2
Authors: Prayitno T B , Hakim D F , Jonuarti R 
Published: October 2024

Abstract
Implementation of the classical Boltzmann transport theory has been performed to calculate the power factor, as well as the figure of merit in a single-layer NiBr2 after performing density functional theory. Those two properties were formulated from the Seebeck coefficient, electron thermal conductivity, and electrical conductivity. An in-plane ferromagnetic formation of magnetic moments in the Ni atoms was applied in the primitive cell. We found a small power factor, but a high figure of merit at the Fermi level near critical temperature. Since the efficiency of thermoelectric materials is represented by the figure of merit, a single-layer NiBr2 is a strong candidate for thermoelectric materials which can be applied in future devices.
Navigating Urban Skies: Obstacle Avoidance Strategies for Quadrotor MAVs
Authors: Pebrianti Dwi , Kee Wong Jack , Bayuaji Luhur , Solichin Achmad 
Published: October 2024

Abstract
Micro Aerial Vehicles (MAVs) has gained attentions since more than two decades ago starting from the applications in air combat up to civil applications such as packet deliveries, environmental monitoring, and surveillance. In an environment such as cities that grows denser, navigation and control for drones becomes challenging to ensure safe navigation around buildings and other obstacles. This study proposes an approach for obstacle avoidance for MAVs by using ultrasonic sensors. Four sensors are strategically positioned to cover the front, right, back, and left directions. Additionally, a downward-facing sensor measures the quadrotor’s height above ground. Our goal is to develop autonomous MAV that can avoid obstacles, ensuring safe flight even in complex urban landscapes. The scenario implemented in the study is by introducing obstacle in any directions. When an obstacle is detected by the ultrasonic sensor, the signal will be sent to microcontroller and the attitude of the MAVs, roll or pitch will be adjusted to avoid the obstacle by moving to the counter direction of the obstacle. We conducted 20 trials of experiments by varying the gain values of Proportional Integral Derivative (PID) values, we fine-tune our obstacle avoidance algorithm. Modifications include optimizing roll and pitch adjustments, refining detection height thresholds, and implementing countermeasures after obstacle clearance. The results show that our proposed method has 10% overshoot when detecting any obstacles in different directions to avoid the obstacles. Our findings contribute to the advancement of safe and efficient urban drone operations, bridging the gap between technology and real-world challenges.
Simulating 2D Fluid Motion with the Smooth Particle Hydrodynamic Approach
Authors: Nooreza K , Wungu T D K , Sobar F T A 
Published: October 2024

Abstract
Virtual two-dimensional (2D) fluid simulation is useful for directly simulating fluids in various situations, including geological simulations for landslides and fluid simulations for teaching. This research aims to simulate the behaviour of three different types of fluids (water, coconut oil, and glycerine) in a 2D container and analyse how these three types of fluids behave under various conditions, including interactions with boundaries. The research used Python programming to simulate fluids and the Wondershare Filmora X application to combine images. The Smooth Particle Hydrodynamics method simulated fluid in a 2D container with 10,000 particles by deriving the force density field directly from the Navier-Stokes equations. The Navier-Stokes equations were utilized to find the acceleration and velocity of fluid particles by considering external forces, internal forces, and gravity through this method. Acceleration and velocity were validated due to wall collisions, collisions with boundaries, and collisions between particles, which caused changes in particle position and velocity. During visualization, the fluid velocity decreased over time due to attenuation caused by interactions between neighbour particles, particles with boundaries, and particles with walls. From the simulation, it was observed that the fluid flowed from a higher place to a lower place, with fluid particles taking the shape of the container and the surface of the fluid forming waves. On the other hand, simulations with boundaries indicated that smaller gap sizes and higher viscosities led to increased difficulty in fluid penetration into the gap within the container.