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INDONESIA
Science and Technology Indonesia
Published by Universitas Sriwijaya
ISSN : 25804405     EISSN : 25804391     DOI : -
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
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Articles 551 Documents
Bismuth Silicate/Silica-Titania Synthesis from In Situ Decomposition of Oil Palm Leaves as Silica Source Salprima Yudha S; Morina Adfa; Swadexi Istiqphara; Muhamad Alvin Reagen
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.397-402

Abstract

In this work, bismuth silicate-titania has been synthesized in two stages by utilizing bismuth oxynitrate as an elemental source of bismuth, oil palm leaves (OPL) as a source of silica and titanium tetraisopropoxide (TTIP) as source of titania (TiO2). In the first stage,bismuth silicate/silica (Bi4Si3O12/SiO2) was formed, which occurs due to the in-situ decomposition of palm leaves and reacts directly with the bismuth precursor at high temperatures (900oC). The reaction could possibly occur through a solid-state reaction mechanism between bismuth oxide and silica or through a more complex mechanism within the reaction mixture. The resulting product then reacts with TTIP, which is added and heated at the same temperature to form Bi4Si3O12/SiO2-TiO2 (bismuth silicate/silica-titania). Characterization of the as-prepared product using X-ray diffraction showed the dominance of bismuth silicate and small amount of titania (TiO2). As a result, TiO2 could not be detected in the diffractogram. Nevertheless, an analysis using energy-dispersive X-rays showed the presence of titanium elements in the resulting composite. The results of this study can be used to develop ternary metal oxides based on natural resources and agricultural wastes, such as oil palm leaves.
Dynamics of Extreme Rainfall and Its Impact on Forest and Land Fires in the Eastern Coast of Sumatra Hamdi Akhsan; Muhammad Irfan; Supari; Iskhaq Iskandar
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.403-413

Abstract

This article examines the extreme climate events on the Eastern Coast of Sumatra over four decades (1981-2019) based on the extreme rainfall index defined using the Expert Team on Climate Change Detection and Indices (ETCCDI). The indices used include Consecutive Dry Day (CDD and the total rainfall per year (PRCPTOT). Theses indices were calculated and are based on the daily observation data from eight quality-controlled weather stations. While overall trends in extreme rainfall indices are not significant, there is a noticeable trend towards drought, with CDD rising by 1.23 days per decade and PRCPTOT decreased by 3.16 mm/year. The correlation between the Dipole Mode Index (DMI) and extreme rainfall indices in the August-September-October-November (ASON) period was positive, with CDD increasing with the more positive DMI value. On the other hand, the PRCPTOT index showed a decrease as the DMI more positive. The ENSO index and CDD are positively correlated during the dry season, while ENSO index negatively correlates with PRCPTOT. The duration of CDD during El Niño/positive Indian Ocean Dipole (IOD) events in 1997, 2015, and 2019 had significant impact on the forest and land fires on the Eastern Coast of Sumatra. The results are useful for policymakers in preventing forest and land fires on the Eastern Coast of Sumatra.
Preparation of Al2O3 /PVA Nanocomposite Thin Films by a Plasma Jet Method Saba Jawad Kadhem
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.471-478

Abstract

Alumina thin films have significant applications in the areas of optoelectronics, optics, electrical insulators, sensors and tribology. The novel aspect of this work is that the homogeneous alumina thin films were prepared in several stages to generate a plasma jet. In this paper, aluminium nanoparticles suspended in vinyl alcohol were prepared using exploding wire plasma. TEM analysis was used to determine the size and shape of particles in aluminium and vinyl alcohol suspensions; the TEM images showed that the particle size is 17.2 nm. Aluminium/poly vinyl alcohol (Al/PVA) thin films were prepared using this suspension on quartz substrate by plasma jet technique at room temperature with an argon gas flow rate of 1 L/min. The Al/PVA thin films were thermally converted to alumina films, where they were annealed at different temperatures (700, 800, or 900°C). X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques were used to characterise these thin films before and after annealing process. The diffraction patterns of the prepared thin films before subjecting them to the annealing process indicated the presence of peaks belonging to aluminium and PVA; however, the diffraction patterns and FTIR spectra obtained for these films after the annealing process showed peaks indicating the formation of alumina films of different phases. AFM and SEM investigations proved that the formed particles for all prepared films before and after the annealing process were similar in size and almost spherical; the diameter of the particles was on the order of a few nanometres. To control the properties of prepared thin films, the plasma which was used to produce thin films is diagnosed spectrophotometrically. The generated plasma was diagnosed using optical emission spectroscopy to estimate the electron temperature Te; the electron temperature was 1.925 eV.
Gastroprotective Effects of Dendropthoe pentandra Leaf Ethanol Extract on Peptic Ulcer Animal Models Fitrya Fitrya; Annisa Amriani; Rennie Puspa Novita; Fadila Kurnia
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.382-387

Abstract

Dendrophthoe pentandra (Loranthaceae) is a semi-parasitic plant with several diverse metabolites and biological activities and is widely used in traditional medicine. This study aims to evaluate the gastroprotective effectiveness of the ethanol extract of D. pentandra leaves in animals induced by an acute peptic ulcer with absolute ethanol. The gastroprotective effect of the extract (100, 250 and 500 mg/kg doses) was evaluated through ulcer index parameters, physicochemical properties of gastric fluid, and histopathological analysis. The study results of the study showed that the ethanol extract of D. pentandra leaves at a dose of 500 mg/kg could provide a protective effect equivalent to omeprazole. Histopathological analysis proved the improvement of the mucous membrane structure in the animals pre-treated with the extract. Based on these findings, it can be concluded that the ethanol extract of D. pentandra leaves is effective as an anti-ulcer drug, so it is feasible to be developed as a gastroprotective from herbal.
Hydroxyapatite-ZnO Biomimetic Toothpaste Formulation from Rice Snail Shell Waste Wisaeni Intannia; Charlena Charlena; Irma Herawati Suparto
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.486-493

Abstract

Toothpaste is a preparation for dental treatment to clean, beautify, and replace minerals that decay from the surface of the teeth. Prevention of damage to the mineral layer of the teeth, the addition of remineralizing agents to toothpaste preparations in the form of hydroxyapatite-ZnO composites is carried out. This study aims to synthesize and characterize hydroxyapatite-ZnO, as well as to formulate hydroxyapatite-ZnO toothpaste from rice field conch shell waste. Hydroxyapatite-ZnO composites have been successfully synthesized using the sol-gel method and characterized using X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX). The XRD result obtained a crystal size of 59.90 nm with a crystallinity percentage of 68.85%. The absorption band at a wave number of 452 cm−1 is an indication that the ZnO compound has been successfully combined with hydroxyapatite. SEM-EDX analysis showed that the morphology of the compound was granular with a rough surface, uneven size, and shape. The results of the hydroxyapatite-ZnO toothpaste formulation in the 45% formula had good physical stability compared to other formulas. The antibacterial properties of hydroxyapatite-ZnO toothpaste preparations showed a very strong inhibitory effect on Streptococcus mutans bacteria. The results of the hydroxyapatite-ZnO toothpaste formulation in the 45% formula had good physical stability compared to other formulas. The antibacterial properties of hydroxyapatite-ZnO toothpaste preparations showed a very strong inhibitory effect on Streptococcus mutans bacteria. The results of the hydroxyapatite-ZnO toothpaste formulation in the 45% formula had good physical stability compared to other formulas. The antibacterial properties of hydroxyapatite-ZnO toothpaste preparations showed a very strong inhibitory effect on Streptococcus mutans bacteria.
Optimization of Sumatera Bentonite by Ammonium-impregnated as a Coagulant for Cassava Wastewater Treatment Yusuf Mathiinul Hakim; Mokhamad Yusup Nur Khakim; Amatullah Hanifah; Risfidian Mohadi
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.443-450

Abstract

The original Sumatera Bentonite (SB), which has been impregnated to be ammonium bentonite (NH-B), was applied as a cassava wastewater coagulant. The modification was conducted using multi-step impregnation initiated by bentonite activation (sodium cation exchange), followed by ammonium impregnation. The optimization parameter focused on the coagulant dose that was used. The result of cassava wastewater coagulation by the ammonium-impregnated bentonite (with dose: 0.4 g/100 mL) shows high-efficiency reduction for turbidity up to 73.97% (from 1099 to 186 NTU), Total Suspended Solid up to 86.56% (from 588 to 79 mg/L), and Chemical Oxygen Demand up to 88.6% (from 559.7 to 63.3 mg/L). The existence of ammonium impregnated is characterized by X-Ray Diffraction analysis based on 2theta shifting at 10° and Fourier Transform Infra-Red analysis at 464, 521, and 1429 cm−1 as ammonium binding.
Activated Hydrochar Prepared from Longan Fruit (Dimocarpus longan Lour.) Peel via Hydrothermal Carbonization-NaOH Activation for Cationic Dyes Removal Neza Rahayu Palapa; Alfan Wijaya; Nur Ahmad; Amri Amri; Risfidian Mohadi; Aldes Lesbani
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.461-470

Abstract

Hydrothermal carbonization is recognized as a method of processing biomass into carbon-rich products due to its energy-saving and environmental-friendly advantages. In this study, two types of hydrochar were prepared from Longan Fruit (Dimocarpus longan Lour.) Peel via hydrothermal carbonization at temperatures of 190°C and 250°C and activated using NaOH (HC-ACT 190 and HC-ACT 250) for removal of malachite green (MG) and rhodamine B (RhB) dyes. The maximum capacity for MG dye removal using HC-ACT 190 and HC-ACT 250 materials was 172.414 mg/g and 250 mg/g, while for RhB dye was 111.111 mg/g and 151.515 mg/g, respectively. The optimum pH was obtained at pH 6 for MG and pH 3 for RhB with adsorption equilibrium time occurring at 90 minutes. The kinetic study shows that the adsorption process follows pseudo-second-order kinetics, while the isotherm model was determined by the Langmuir isotherm model. Materials can be reused effectively for at least 3 cycles with an adsorption percentage of MG dye removal using HC-ACT 190 and HC-ACT 250 materials was 69.91% and 83.15% respectively, while for RhB dye was 35.79% and 55.6% respectively. The material is more selective on MG dye compared to RhB dye based on the selectivity test on the adsorption of the dye mixture.
Catalytic Oxidative Desulfurization of 4-Methyldibenzothiophene by Ni/Al Modified Titanium Dioxide and Zinc Oxide Risfidian Mohadi; Neza Rahayu Palapa; Sahrul Wibiyan; Mardiyanto; Rohmatullaili; Erni Salasia Fitri; Aldes Lesbani
Science and Technology Indonesia Vol. 8 No. 3 (2023): July
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.2023.8.3.414-421

Abstract

In this study, composite layer double hydroxide-metal oxide catalysts (Ni/Al-TiO2 and Ni/Al-ZnO) were successfully prepared and utilized for the oxidative desulfurization of dibenzothiophene. The catalysts were characterized using XRD, FTIR, and SEM-EDS analysis. The diffraction patterns confirmed the successful synthesis of the composite materials, while the FTIR spectra exhibited absorption bands at specific wavenumbers 3480 cm-1, 1630 cm-1, 1376 cm-1, 830 cm-1, 775 cm-1, and 683 cm-1. The surface morphology of the catalysts showed variations, with Ni/Al-LDH having a smooth particle surface and long particle shape, while Ni/Al-ZnO and Ni/Al-TiO2 formed grain-like or aggregated structures. EDS analysis confirmed the presence of Ni/Al, Ti, and Zn elements in the composites, with Ti and Zn accounting for 29.3% and 10.7% of the composite mass, respectively. The optimized reaction conditions included a reaction time of 40 minutes, catalyst dosage of 0.25 g, temperature of 50°C, and the use of n-hexane as the solvent. The catalysts demonstrated a heterogeneous nature and proved to be reusable, as the conversion of dibenzothiophene remained above 90% even after three catalytic reactions, with Ni/Al-TiO2 and Ni/Al-ZnO composites maintaining conversion rates of 99.36% and 99.32%, respectively.
Modification of Pt-Porous Composite Material (Pt-PCM) and Its Application for Electroanalysis of Uric Acid and Electrosynthesis of Acetic Acid from Ethanol Riyanto; Nurhasanah; Mohamed Rozali Othman
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.2023.8.4.554-559

Abstract

Research on the synthesis of Pt-Porous Composite Material (Pt-PCM) has been done. This material is used for the electrochemical activity of uric acid and electrochemical synthesis of acetic acid from ethanol. Pt-PCM is made by mixing 99.995% platinum powder and PVC or Poly (vinyl chloride) homogeneously with a homogenizer for 3.0 h, plus tetrahydrofuran solvent, and pressed with a strength of 10 tons/cm2. The material produced was analysis using Scanning Electron Microscopy (SEM), voltammetry potential V and Tafel plot. The material is used as an electrode for the determination of uric acid and the synthesis of acetic acid from ethanol. The results showed that Pt-PCM has evenly distributed pores and has a perfect Tafel slope compared to metal platinum or solid platinum. Pt-PCM also has the excellent ability as a working electrode for the analysis of uric acid in human urine and electro synthetic acetic acid from alcohol. In conclusion, Pt-Porous Composite Material (Pt-PCM) is a porous material, so it is excellent as a candidate for electrodes.
In Silico Analysis of Phenolic Compounds from Ceriops decandra Griff. Leaves and Molecular Interaction as Anti Diabetes Yunita Eka Puspitasari; Mochamad Arega Alfikri; Romasni Sitanggang; Jeny Ernawati Tambunan; Hardoko Hardoko
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.2023.8.4.542-553

Abstract

α-amylase and α-glucosidase in the gastrointestinal tract have an important role in the hydrolysis α-1,4 and α-1,6 glycosidic chain of starch, respectively. Inhibition of both enzyme activities becomes one of the strategies to control diabetes. However, commercial drugs such as antidiabetics have adverse effects such as gastrointestinal problems. Therefore, exploring functional food, especially from marine natural products as antidiabetic agents, is potential. In particular, Ceriops sp. was reported to contain bioactive compounds with antidiabetic properties, but its mechanism to treat diabetes has not been proved. The potency of phenolic compounds of C. decandra leaves as α-amylase and α-glucosidase inhibitors were examined in this research by implementing the molecular docking analysis in silico. Three steps of analysis were carried out in this study, including extraction from C. decandra leaves with different polarity solvents, identification of phenolic compounds using LC-HRMS, and molecular docking analysis of phenolic compounds identified from C. decandra leaves. This study revealed that quercetin, rutin, epicatechin, isorhamnetin, caffeic acid, and ferulic acid were identified from C. decandra leaves. According to the drug-likeness and toxicity analysis, the presented compounds in C. decandra leaves had high potential pharmacological properties. Furthermore, molecular interaction analysis exhibited phenolic compounds extracted with ethyl acetate, such as quercetin and epicatechin, and with methanolic extracts, such as quercetin, rutin, epicatechin, and isorhamnetin, were more effective as α-amylase and α-glucosidase inhibitors than from caffeic acid and ferulic acid. Among the phenolic compounds of C. decandra leaves, rutin and quercetin were predicted to be the potential α-glucosidase inhibitors.