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INDONESIA
Science and Technology Indonesia
Published by Universitas Sriwijaya
ISSN : 25804405     EISSN : 25804391     DOI : -
Core Subject : Science, Social, Engineering,
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Environmental Science Materials Science & Nanotechnology Physics
An international Peer-review journal in the field of science and technology published by The Indonesian Science and Technology Society. Science and Technology Indonesia is a member of Crossref with DOI prefix number: 10.26554/sti. Science and Technology Indonesia publishes quarterly (January, April, July, October). Science and Technology Indonesia is an international scholarly journal on the field of science and technology aimed to publish a high-quality scientific paper including original research papers, reviews, short communication, and technical notes. This journal welcomes the submission of articles that covers a typical subject of natural science and technology such as: > Chemistry > Biology > Physics > Marine Science > Pharmacy > Chemical Engineering > Environmental Science and Engineering > Computational Engineering > Biotechnology Journal Commencement: October 2016
Arjuna Subject : -
Articles 551 Documents
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The Electrochemical Conversion of CO2 into Methanol with KHCO3 Electrolyte Using Membrane Electrode Assembly (MEA) Dedi Rohendi; Nyimas Febrika Sya’baniah; Edy Herianto Majlan; Nirwan Syarif; Addy Rachmat; Dwi Hawa Yulianti; Icha Amelia; Dimas Ardiyanta; Isya Mahendra; Rr. Whiny Hardiyati Erliana
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.632-639

Abstract

The electrochemical conversion process of CO2 into methanol using Membrane Electrode Assembly (MEA) has been done. The MEA consists of a Pt/C catalyst in the cathode and a Cu2O ZnO/C catalyst in the anode. The electrodes were made using the spraying method and then characterized using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) methods to determine the ECSA (Electrochemical Surface Area) and electrical conductivity values. Besides that, also X-Ray Diffraction (XRD) and Scanning Electrode Microscopy – Energy Dispersive X-Ray (SEM-EDX) analysis was to determine the crystal and morphological structure. The voltammogram from CV analysis indicated that the ECSA value on the Pt/C electrode was 7.2 m2/g and the Cu2O-ZnO/C electrodes as 0.69 m2/g. The electrode’s electrical conductivity value with Pt/C catalyst was 1.15 x 10−3 S/cm, and the electrode with Cu2O-ZnO/C catalyst was 0.80 x 10−3 S/cm. The results of the XRD analysis confirmed the presence of Cu2O and ZnO on the Cu2O-ZnO/C electrode and Pt on the Pt/C electrode. Meanwhile, the results of the SEM-EDX analysis showed that the Pt/C catalyst was spread more evenly with a larger percentage than Cu2O and ZnO. The result of the conversion of CO2 to methanol was measured using a methanol analyzer with variations in KHCO3 electrolyte concentration, variation of temperature operation, and variation of time operation. The best methanol concentrations after distillation process were 79.06 w/v %, with 1 M KHCO3, at room temperature and 2 hours operation.
One-pot Hydrothermal Synthesis and Characterization of Zirconium Oxide Nanoparticles Suresh Sagadevan; Jayasingh Anita Lett; Is Fatimah
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.585-593

Abstract

Zirconia (also known as zirconium dioxide, ZrO2) is a white crystalline naturally occurring mineral that offers excellent optical, dielectric, and mechanical properties. Considering these properties and referring to previous studies on the optimization of ZrO2 NPs synthesis, in the present study, we studied the crystalline, optical, and fluorescence properties of ZrO2 nanoparticles (NPs) formed by the hydrothermal synthesis route. The physicochemical features of the nanoparticles were examined in the photocatalytic oxidation of rhodamine B. From the powder XRD analysis, the ZrO2 NPs were found to be highly crystalline, while the fluorescence (FL) spectra indicated an emission band at 473 nm, which could be linked to a blue shift. Also, the FTIR and Raman spectroscopies confirmed the functionality and bonding, and in addition, the XPS analysis provided the elemental peaks of Zr 3d and O 1s, where all these analyses evidenced the successful formation of ZrO2. Examination of the photocatalytic activity of ZrO2 NPs revealed the capability of the material for rhodamine B photocatalytic degradation effectively, with a degradation efficiency of 86% after 2 h of treatment. Moreover, the nanoparticles exhibited stability and reusability over five cycles. Overall, from the analysis, ZrO2 NPs can be easily formed via the hydrothermal route with tailored optical and fluorescence properties to find applications in the electronics industry for the manufacturing of light emitting devices.
An Assessment of Pb and Cu in Waters, Sediments, and Mud Crabs (Scylla serrata) from Mangrove Ecosystem Near Tanjung Api-Api Port Area, South Sumatra, Indonesia Rozirwan; Aning Puji Saputri; Redho Yoga Nugroho; Nadila Nur Khotimah; Wike Ayu Eka Putri; Fauziyah; Anna Ida Sunaryo Purwiyanto
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.675-683

Abstract

Heavy metal pollution from anthropogenic activities can harm aquatic ecosystems. This study aims to determine the concentration of heavy metals (Pb and Cu) in waters, sediments, and mud crabs (Scylla serrata), and to analyze the relationship between environmental parameters and S. serrata consumed by humans. Samples were taken in the mangrove ecosystem around the Tanjung Api-Api port area in South Sumatra, Indonesia. Pb and Cu analysis used the Atomic Absorption Spectrophotometer (AAS). Pb and Cu linkages in waters, sediments, and S. serrata analyzed by SigmaPlot V12.5 and Principal Component Analysis (PCA) analyzed by XLSTAT 2022. The limit consumption of S. serrata was calculated using MWI (Maximum Weekly Intake) and MIT (Maximum Intake Tolerance). Based on the results, the heavy metal Pb in water was 0.1055 – 0.1322 mg.L-1, and Cu was not detected. Furthermore, Pb in sediments ranged from 7.0104 - 11.8186 mg.kg-1, Cu 3.7127 - 4.5347 mg.kg-1, and Pb in S. serrata ranged from 0.0001 - 0.0021 mg.kg-1, and Cu ranged from 0.03 – 0.0791 mg.kg-1. The concentration of heavy metals in water, sediment, and S. serrata had not exceeded the specified quality standard, except for Pb in water. The principal component analysis obtained F1 (44.35%), F2 (27.53%) and F3 (17.83%) groups. Based on MWI and MIT value, it showed high quality which concluded S. serrata was still safe for human consumption.
Improve Fuzzy Inventory Model of Fractal Interpolation with Vertical Scaling Factor Eka Susanti; Fitri Maya Puspita; Siti Suzlin Supadi; Evi Yuliza; Ahmad Farhan Ramadhan
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.654-659

Abstract

The inventory model is used to determine the optimal inventory of a product. In certain cases, parameters in the inventory model are uncertain. Fractal interpolation techniques can be used to overcome parameter with uncertainty. Fractal interpolation results are affected by the fractal interpolation function and the vertical scaling factor. The vertical scaling factor is positive and less than 1. In this study, fractal interpolation techniques are introduced with variations in vertical scaling factor to overcome the uncertainty of demand data in inventory models. Furthermore, the interpolation results are used in fuzzy inventory models and expressed by Trapezoidal Fuzzy Number. This paper considers an inventory model with varying demand to optimize rice inventory. Based on the data obtained, the accuracy level will increase for the vertical scaling factor values close to 1. Optimal rice inventory of each successive fuzzy parameter is 1447963, 1013914, 504950, 215312. If the cost parameter is increased, then the amount of inventory is decreases.
Monitoring the Muara Laboh Geothermal Field in Indonesia using the ISBAS Method with Sentinel-1 SAR Images Mokhamad Yusup Nur Khakim; Takeshi Tsuji; Erni; Akhmad Aminudin Bama; Frinsyah Virgo; Muhammad Irfan; Azhar Kholiq Affandi; Toshifumi Matsuoka
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.626-631

Abstract

The Muara Laboh geothermal field lies in a South Solok basin zone, West Sumatra, Indonesia. Production and reinjection of geothermal fluids into the underground reservoir commonly induce crustal deformation. The study area is covered by 63.8% plantation, primary, and secondary forests, which limit the ability of conventional InSAR techniques. Therefore, an Intermittent Small BASeline Subset (ISBAS) analysis has been performed to estimate line-of sight (LOS) displacement time series due to geothermal production using the Sentinel-1 dataset between 8 March 2021 and 15 March 2022. The localized subsidence with ∼30 mm/yr rate over this tropical geothermal field has been revealed by using the ISBAS. The subsidence coincides with an area of the Muara Laboh geothermal reservoir. We suggest that geothermal production induced subsidence. In addition, the deformation in this geothermal field was controlled by faults and seasonally influenced by rainfall. Therefore, deformation variation was correlated with fluctuations in rainfall patterns. The geothermal reservoir system exhibited elastic expansion in response to seasonal recharge events during the rainy season.
Formulation and Evaluation of Antibacterial and Anti-Inflammatory Capsules Containing Phyllanthus emblica L. Fruit Nanoparticles Masfria; Sumaiyah; Hafid Syahputra; Marwin Witarman
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.607-615

Abstract

Phyllanthus emblica fruit has diuretic, antibacterial, hepatoprotective, antitumor, hypocholesterolemic, antioxidant, and antiulcerogenic activities making it possible as a traditional medicine in capsule form. Capsule preparations have the advantage of covering the unpleasant taste and smell of medicinal ingredients, easy to swallow, so they are practical to use. This study aimed to formulate Phyllanthus emblica fruit nanoparticles in capsules and to test the antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa and anti-inflammatory activity by observing denaturation inhibition in vitro. The method used to manufacture Phyllanthus emblica fruit simplicia nanoparticles was used using a High Energy Ball mill grinding machine. Capsule formulation was carried out with various doses of nanoparticles (100, 150, and 200 mg). Evaluation includes weight uniformity and disintegration time. Test of its antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa and its anti inflammatory activity in vitro. The study found that all formulas could be made into capsules that met the evaluation test requirements. The results of the evaluation of disintegration time ranged from 6.17-11.33 minutes. For the evaluation results of weight uniformity, it was found that weight deviations in columns A1 and A2 were in the range between 0.9% to 2.8% and 0.9 to 1.3%. The study reports on the antibacterial activity of Phyllanthus emblica fruit nanoparticle capsules (PFNP) against Streptococcus mutans and Pseudomonas aeruginosa. The results indicate that PFNP exhibits a dose-dependent antibacterial effect, with inhibition zone diameters of 10.83 mm, 11.6 mm, and 12.63 mm observed at 100 mg, 150 mg, and 200 mg, respectively, against Streptococcus mutans. Similarly, PFNP demonstrated a dose-dependent antibacterial effect against Pseudomonas aeruginosa, with inhibition zone diameters of 10.7 mm, 11.4 mm, and 12.1 mm observed at doses of 100 mg, 150 mg, and 200 mg, respectively. PFNP capsules showed inhibition results with a value of 5.63%, 6.13%, and 6.80%. It was concluded that Phyllanthus emblica fruit nanoparticles (Phyllanthus emblica L.) could be formulated in capsule dosage forms with doses of 100 mg, 150 mg, and 200 mg; has antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa, and has no anti-inflammatory activity.
Studying the Structure Properties of Copper Nanoparticles Prepared by Chemical Reduction Method Noora H. Al-Zobiadi; Ammar A. Habeeb; Awatif S. Jasim
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.640-646

Abstract

The chemical reduction method (CRM) can produce high purity nanoparticles, it is a down-top chemical method based on the principle of salt reduction, this method is used in this work to synthesis copper nanoparticals (CuPNs) by use different concentrations of copper nitrate. The properties of the prepared nanoparticles were studied by fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy were used to measure the absorbance spectra of the produced particles. According to the scanning electron microscope (SEM), the particles’ diameters range from (61.64 to 49.25) nm. According to X-ray diffraction, the particles exhibit a face monoclinic crystal structure (FCC). According to the transmission electron microscope findings, the particles are asymmetrically spherical in shape.
Formation of Hydroxyl-Amide Solid Dispersion Involving Azithromycin and Chitosan-Alginate Biopolymer to Increase the Dissolution Rate of Azithromycin Mardiyanto; Budi Untari; Ady Mara; Diko Fahri Ferdiansyah
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.647-653

Abstract

Research to increase the solubility of active pharmaceutical ingredients is usually conducted by reducing the particle size. This research is one side that used the solid dispersion systems to increase solubility, especially on macrolide antibiotics for which there is still little information. The co-grinding technique on azithromycin-chitosan-alginate was chosen to produce a solid dispersion system. The parameters observed were changes in crystal structure, FTIR spectral patterns, morphological changes, and dissolution profile changes. The results of this research showed a change in the pattern of X-diffraction of azithromycin, physical interaction between azithromycin and the polymer, changes in the image of surface of solid dispersions, the solubility of solid dispersions in simulated-intestinal-fluid (SIF) solutions, and an increase in the dissolution rate of azithromycin indicating that the co-grinding technique to produce solid dispersions can increase the solubility of azithromycin.
Solving the Shortest Total Path Length Spanning Tree Problem Using the Modified Sollin and Modified Dijkstra Algorithms Wamiliana; Reni Permata Sari; Astri Reformasari; Jani Suparman; Akmal Junaidi
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.684-690

Abstract

In a weighted connected graph, the shortest total path length spanning tree problem is a problem when we need to discover the spanning tree with the lowest total cost of all pairwise distances between its vertices. This problem is also known as the minimum routing cost spanning tree (MRCST). In this study, we will discuss the Modified Sollin and Modified Dijkstra Algorithms to solve that problem which implemented on 300 problems are complete graphs of orders 10 to 100 in increments of 10, where every order consists of 30 problems. The results show that the performance of the Modified Dijkstra and the Modified Sollin Algorithms are slightly similar. On orders 10, 20, 30, 60, and 80, the Modified Dijkstra Algorithm performs better than the Modified Sollin, however on orders 40, 50, 70, 90, and 100, the Modified Sollin performs better.
Fabrication and Characterization Fe3O4/Humic Acid for the Efficient Removal of Malachite Green Nur Ahmad; Zaqiya Artha Zahara; Alfan Wijaya; Fitri Suryani Arsyad; Idha Royani; Aldes Lesbani
Science and Technology Indonesia Vol. 8 No. 4 (2023): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.4.616-625

Abstract

The dye pollutants that contaminate water and food resulting from commercial manufacture and illicit addiction are a worldwide threat that harms the ecosystem, the food supply, and the health of humans. Magnetite/Fe3O4 humic acid (MHA) with various ratios was synthesized using a two-step process involving coprecipitation and hydrothermal treatment in order to effectively overcome these obstacles. Analyses of SEM, XRD, FTIR, and VSM were used to describe the morphology and physicochemical aspects of MHA. The adsorption kinetics studies indicated that the adsorption mechanism of malachite green adhered to the pseudo-second-model and that the adsorption was adequately described by the Langmuir isotherm. The thermodynamic studies demonstrated spontaneous, endothermic, disorderly adsorption. MHA2 had maximal malachite green adsorption capacities of 83.333 mg/g. Malachite green and MHA may interact via interaction, electrostatic attraction, van der Waals forces, H-bonding, pore filling, pore locking, and/or mechanical adhesion; however, physisorption dominates the adsorption process. Malachite green's adsorption characteristics change significantly after up to four cycles. It has been demonstrated that MHA has a high capacity for dye adsorption and a broad range of potential applications.

Page 30 of 56 | Total Record : 551

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