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Journal : Science, Technology, and Communication Journal

Performance analysis of metamaterial antennas based on variations in combination and radius of hexagonal SRR Soerbakti, Yan; Defrianto, Defrianto; Rini, Ari Sulistyo; Asyana, Vepy
Science, Technology and Communication Journal Vol. 4 No. 1 (2023): SINTECHCOM Journal (October 2023)
Publisher : Lembaga Studi Pendidikan and Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v4i1.250

Abstract

The low antenna performance is a concern for researchers to overcome in modern technology. As an effort to overcome this problem, the application of the metamaterial structure to the antenna was carried out to increase the antenna parameters. This study aims to analyze the effect of antenna performance due to the influence of variations in the combination and radius of the SRR hexagonal metamaterial. The research was conducted in a simulation, starting with designing the antenna structure with the metamaterial of two rings into a resonator with a radius variation of 2.5 mm and 2.7 mm, then combining one to four hexagonal SRRs. The results showed that the highest antenna performance was obtained from a combination of four hexagonal SRRs for a radius of 2.7 mm with parameter values in the form of return loss -38.95 dB, a bandwidth of 7.88 GHz at a working frequency of 1.12 – 9.00 GHz and a gain of 5.92 dBi.
Potential multi-detection manifestation of ultra-sensitive sensors based on ZnO thin films and metamaterials Defrianto, Defrianto; Soerbakti, Yan; Saktioto, Saktioto; Rini, Ari Sulistyo; Fadhali, Mohammed; Yupapin, Preecha
Science, Technology and Communication Journal Vol. 5 No. 1 (2024): SINTECHCOM Journal (October 2024)
Publisher : Lembaga Studi Pendidikan and Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v5i1.265

Abstract

This study aims to observe the ability of a thin layer of zinc oxide (ZnO) which is applied to sensor technology. Currently, the low detection limit of the sensor is a problem in its use. Metamaterials offer resonant properties in increasing sensitivity, but their performance is still below the current high modern technology. The high engineering properties of metamaterials provide opportunities for realizing renewable metamaterials. ZnO thin layer semiconductor material as a transparent conductive oxide can provide a wide detection potential. The ability of ZnO thin films to be adapted to metamaterial sensors can be further investigated and improved for the future.
Green-synthesized ZnO and Ag nanoparticles: A comparative study of optical, morphology and structural properties for photocatalytic applications Hamzah, Yanuar; Emrinaldi, Tengku; Dewi, Rahmi; Rini, Ari Sulistyo; Umar, Lazuardi; Simatupang, Mediniah Putri; Rabiah, Rabiah; Noferdi, Muhammad Deri
Science, Technology, and Communication Journal Vol. 5 No. 3 (2025): SINTECHCOM Journal (June 2025)
Publisher : Lembaga Studi Pendidikan dan Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v5i3.307

Abstract

In this study, zinc oxide (ZnO) and silver (Ag) nanoparticles were synthesized using Annona muricata leaf extract as a reducing and stabilizing agent with variations in the molar ratio of 1:3, 1:5, and 1:7. Optical characterization using UV-Visible spectroscopy revealed that the variations of molar ratio influence the absorption peak and band gap energy of the resulting ZnO and Ag. UV-Vis results show that the molar ratio 1:5 was optimal for synthesizing ZnO and Ag. The band gap value of synthesized ZnO and Ag at a 1:5 molar ratio was 3.27 eV and 2.01 eV, with absorption peaks at 355 nm and 435 nm respectively. XRD characterization shows that ZnO nanoparticles has a hexagonal wurtzite structure with lattice parameters of a = 76 Å and c = 4. 95 Å and for Ag nanoparticles has a face centered cubic structure with lattice parameters a = b = c is 4.15 Å. Annona muricata leaves extract shows photocatalytic properties that can be applied to the degradation of polluted water. This shows that ZnO nanoparticles via green synthesis using Annona muricata leaf extract is a very simple, low-cost and environmentally friendly method.
Argon plasma ionization in thermodynamic equilibrium with continuity equation Kasri, Anshori; Saktioto, Saktioto; Farma, Rakhmawati; Rini, Ari Sulistyo; Erwin, Erwin; Awitdrus, Awitdrus
Science, Technology, and Communication Journal Vol. 5 No. 3 (2025): SINTECHCOM Journal (June 2025)
Publisher : Lembaga Studi Pendidikan dan Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v5i3.318

Abstract

Local thermodynamic equilibrium is a foundational concept in plasma physics and heat transfer, describing a state where each small region of a system can be treated as if it is in thermodynamic equilibrium, even if the whole system is not. However, achieving accurately perfect thermodynamic equilibrium conditions in real-experiments is often challenging. It often struggles for understanding phenomena like excited states or specific Arrhenius-driven reactions. As a result, the advantages of plasma modeling with simplifications can sometimes overshadow the disadvantages of experiments. This study simulated the ionization process of argon plasma using the 4th order Runge-Kutta numerical method. The simulation, initiated with initial densities before the simulation is run, each of them is electrons 2.6 × 1018 m-3, neutral argon (Ar) 2.6 × 1018 m-3, positive argon ions (Ar+) 2.6 × 1018 m-3, and positive diatomic argon ions (Ar2+) 2.6 × 1018 m-3, successfully obtained reaction rate equilibrium data at the 625th iteration. The final densities observed were 2.46 × 1018 m-3 for electrons, 2.27 × 1018 m-3 for neutral argon, 6.4 × 1015 m-3 for Ar+, and 4.34 × 1017 m-3 for Ar2+. These results show the equilibrium reaction rate in argon plasma which provides information that density of electron and Ar+ species show a decreasing trend while density of Ar and Ar2+ species shows an increasing trend which are the result of ionization and recombination processes in the entire plasma system.