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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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Best Proximity Point Results in Fuzzy Normed Spaces Raghad Ibrahaim Sabri; Buthainah Abd Al Hassan Ahmed
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.298-304

Abstract

Fixed point (briefly FP ) theory is a potent tool for resolving several actual problems since many problems may be simplified to the FP problem. The idea of Banach contraction mapping is a foundational theorem in FP theory. This idea has wide applications in several fields; hence, it has been developed in numerous ways. Nevertheless, all of these results are reliant on the existence and uniqueness of a FP on some suitable space. Because the FP problem could not have a solution in the case of nonself-mappings, the idea of the best proximity point (briefly Bpp) is offered to approach the best solution. This paper investigates the existence and uniqueness of the Bpp of nonself-mappings in fuzzy normed space(briefly FN space) to arrive at the best solution. Following the introduction of the definition of the Bpp, the existence, and uniqueness of the Bpp are shown in a FN space for diverse fuzzy proximal contractions such as ?????? fuzzy proximal contractive mapping and ????h ????h - fuzzy proximal contractive mapping.
The Relationship of Multiset, Stirling Number, Bell Number, and Catalan Number Wamiliana; Attiya Yuliana; Fitriani
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.330-337

Abstract

Catalan numbers is not as famous as Fibonacci numbers, however this number has own its beauty and arts. Catalan numbers was discovered by Ming Antu in 1730, however, this numbers is credited to Eugene Catalan when he was studying parentheses in 1838. Catalan numbers mostly occurs in counting or enumeration problems. The Catalan numbers can be defined in more than one forms, and the most famous form is Cn = 1/n+1(2nn). In this study we will discuss the multiset construction and the relationship of the results of Multiset with Stirling, Bell, and Catalan numbers.
Malachite Green Dye Adsorption from Aqueous Solution using a Ni/Al Layered Double Hydroxide-Graphene Oxide Composite Material Amri Amri; Aldes Lesbani; Risfidian Mohadi
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.280-287

Abstract

Ni/Al layered double hydroxide and Ni/Al-graphene oxide composite materials were created using the coprecipitation method. The materials were successfully synthesized and prepared using XRD, FT-IR, and BET studies. The optimal pH as a result of malachite green dye adsorption is pH 4. The kinetics models of all materials follow the pseudo second order model. After being composited with graphene oxide, the maximum adsorption capacity of Ni/Al layered double hydroxide increased from 99.010 to 111.111 mg/g. All materials’ isotherm models adhere to the Langmuir isotherm model. The adsorption process was endothermic and spontaneous. The Ni/Al-graphene oxide composite material has a more stable structure than the Ni/Al layered double hydroxide. The regeneration procedure was repeated five times, and the Ni/Al-graphene oxide composite material did not show a significant decrease until thefifth cycle, when it dropped from 97.561 to 77.046%, however the Ni/Al layered double hydroxide material dropped rapidly from 85.00 to 5.667%.
Facile Fabrication of Layered Double Hydroxide-Lignin for Efficient Adsorption of Malachite Green Neza Rahayu Palapa; Nur Ahmad; Alfan Wijaya; Zaqiya Artha Zahara
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.305-311

Abstract

Preparation of layered double hydroxide-lignin (lignin-Zn/Al) carried out by coprecipitation method. The FTIR spectra of lignin-Zn/Al displayed at 3448, 2939, 1620, 1381, 1118, 1041, and 601 cm−1. The characteristic peaks are located at 10.1°, 19.1°, 20.1°, 29.4°, 33.9°, and 60.4°. The lignin-Zn/Al nitrogen adsorption-desorption isotherm showed a Type-IV curve, indicating that it had a mesoporous structure. The H3 kind of hysteresis loop also provides evidence for the presence of mesopores within the lignin-Zn/Al complex. Lignin-Zn/Al, lignin, and Zn/Al had pHpzc values of 6.09, 3.01, and 6.09, respectively. Lignin-Zn/Al, lignin, and Zn/Al are positively charged when the pH of the solution is less than pHpzc, and they are negatively charged when the pH of the solution is more than pHpzc. The Langmuir and pseudo-second-order model best represented the MG adsorption onto all adsorbents. The lignin-Zn/Al, lignin, and Zn/Al were shown to have maximum Langmuir adsorption capacities of 83.034, 78.740, and 36.364 mg/g, respectively. Zn/Al adsorption capacity increased 2.28 times after being composited with lignin.
Formulation and Evaluation of Azithromycin Dihydrate Solid Dispersion with Esther of Polyethylene Glycol-6000 and Stearic Acid Using A Co-Grinding Technique Mardiyanto; Budi Untari; Ady Mara; Nauval Hady Prasetyo
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.312-320

Abstract

Azithromycin is a narrow-spectrum bacterial growth inhibitory antibiotic derived from macrolides with low dissolution in water. Several methods have been carried out to increase the dissolution of medicinal substances, one of which is solid dispersion. Solid dispersions are mixtures consisting of one or more active substances in an inert carrier. The purpose of this study was to determine the effect of formatting solid dispersions with PEG 6000 polymer and stearic acid on increasing the dissolution rate of azithromycin. The method of formatting solid dispersions uses the co-grinding method. Solid dispersion of azithromycin was prepared in four formulas with variations in the amount of PEG 6000. Tests carried out on solid dispersion samples of azithromycin were XRD, FTIR, SEM, solubility tests, and dissolution tests. Test results on azithromycin solid dispersions prepared by co-grinding showed that there was an effect of the amount of PEG 6000 on decreasing the intensity of azithromycin crystals, there was no chemical interaction between azithromycin and the carrier, differences in the morphology of pure azithromycin powder and solid dispersions, and an increase in the dissolution of solid dispersions in medium SIF.
Optimization of Liquid Smoke Products Made from Rubberwood with Pyrolysis Method Bazlina Dawami Afrah; M. Ihsan Riady; Lia Cundari; Muhammad Andzar Rizan; Jihan Utami; Siti Istiani Pratiwi; Muhammad Yori Pratama
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.2023.8.3.353-360

Abstract

A large amount of rubberwood waste in Indonesia is caused by abundant rubberwood production. However, the utilization of rubberwood waste has not been optimized in Indonesia. One of the efforts to utilize rubberwood waste is to process it into liquid smoke. Liquid smoke is the dispersion of smoke vapor in water. The raw material used in this research is rubberwood. This study aimed to determine the quality of liquid smoke after purification by knowing the volume, density, pH, viscosity, yield, and phenol content using rubberwood as raw material and the pyrolysis method. The pyrolysis process is purified by distillation based on differences in boiling points. This research is divided into two stages of distillation, namely low grade purified liquid smoke and high grade purified liquid smoke. The analysis results will follow the quality standards of Japanese liquid smoke. The results show that the best liquid smoke from this research is liquid smoke with a pyrolysis time of 3 hours because it meets Japanese liquid smoke quality standards.
Synthesis, Characterization of Chitosan-ZnO/CuO Nanoparticles Film, and its Effect as an Antibacterial Agent of Escherichia coli Ahmad Fatoni; Agnes Rendowati; Lasmaryna Sirumapea; Lidya Miranti; Siti Masitoh; Nurlisa Hidayati
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.2023.8.3.373-381

Abstract

The film of chitosan- ZnO/CuO nanoparticles was synthesized. This study were the synthesis and characterization of the chitosan-ZnO/CuO nanoparticles film and its effect as an antibacterial of Escherichia coli. The ZnO, CuO, and ZnO/CuO were biosynthesized by biological method and for the synthesis of the chitosan-ZnO/CuO nanoparticles film, the casting method was adopted. The product was analyzed by FTIR spectroscopy, X-ray diffraction (XRD), and Scanning Electron Microscope (SEM), respectively. The product of chitosan-ZnO/CuO nanoparticles film as paper disk and agar disk diffusion method was selected to study an antibacterial agent of this product. The Zn-O or Cu-O group was observed at a peak between 468-675 cm−1 for ZnO and 503 and 619 cm−1 for CuO nanoparticles, respectively. ZnO, CuO, and ZnO/CuO nanoparticles are in the crystalline form and it has a crystallite size of 13.21, 13.21, and 11.49 nm respectively. After interacting with chitosan, the metal nanoparticles such as ZnO, CuO, and ZnO/CuO nanoparticles can change the crystalline form of chitosan to be amorphous form. The addition of ZnO, CuO, and ZnO/CuO nanoparticles in the chitosan will change the surface morphology of chitosan. Chitosan-ZnO/CuO nanoparticles film can inhibit the growth of Escherichia coli bacteria.
Synthesis of Fe(III)-IIPs (Ion Imprinted Polymers): Comparing Different Concentrations of HCl and HNO3 Solutions in the Fe(III) Polymer Extraction Process for Obtaining the Largest Cavities in Fe(III)-IIPs Novianty; Jaya Edianta; Jorena; Khairul Saleh; Akhmad Aminuddin Bama; Erry Koriyanti; Menik Ariani; Idha Royani
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.2023.8.3.361-366

Abstract

This study was conducted to synthesize Fe (III)-IIPs by free radical polymerization using the cooling-heating method. Cooling processat -5◦C for 1 hour, as well as heating at 75◦C, 80◦C, and 85◦C maintained for 3 hours, 2 hours and 1 hour, respectively. The Fe (III)-IIPs synthesis process involved Fe(NO3)3 with an average diameter of 18.23 nm, methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), benzoyl peroxide (BPO) and ethanol, each of which plays a role as an analyte, functional monomer, cross-linker, initiator, and porogen. The result of the polymerization process was a polymer containing ions namely Fe(III) polymer. The ions need to be removed by the extraction process to produce Fe(III)-IIPs, which act as absorbents. Furthermore, the extraction process is very influential in the process of losing ions and the formation of cavities or templates in the polymer body. The number of cavities formed tends to affect the ability of Fe(III)-IIPs to identify the target ion which has similar physical and chemical properties to the shape of the Fe(III)-IIPs cavity. The extraction process was carried out on Fe(III) polymer samples using HCl and HNO3 solutions with varying concentrations of 3 M and 6 M, respectively. The transmission percentage of FTIR analysis showed that for samples of Fe(III)-IIPs HCl 3 M and 6 M were 94.258% and 95.666%, while for Fe(III)-IIPs HNO3 3 M and 6 M were 92.735%, respectively. The largest percentage was shown in the 6 M HCl IIPs sample, which indicated that there were several ions lost from the polymer body after the extraction process. This is also reinforced by the results of the SEM analysis processed with Matlab, which showed 498 cavities with a distribution of voids on a scale of <100 nm, totaling 470.
Analysis of Extreme Heat Land Surface Temperature at a Tropical City (1988-2022): A Study on the Variability of Hot Spot during El Niño Southern Oscillation (ENSO) Oliver Valentine Eboy; Ricky Anak Kemarau
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.2023.8.3.388-396

Abstract

Weather and climate in Malaysia, situated in Southeast Asia, are influenced by El Niño Southern Oscillation (ENSO), monsoons, Madden Julian Oscillation (MJO), and Indian Ocean Dipole (IOD). Previous studies on ENSO’s impact on temperature lacked detailed spatial information due to limited meteorological stations and cost constraints. This study utilizes remote sensing techniques, employing Landsat satellite data and Oceanic Niño Index (ONI) data, to analyze the spatial pattern of extreme land surface temperature distribution during ENSO events. Preprocessing includes radiometric and atmospheric corrections before converting digital numbers to land surface temperature values. Results indicate increased hotspot areas (>30°C) during El Niño events, with respective hotspot areas of 89.32 km² and 97.8 km² in 2015 and 2016, and 61.23 km² and 59.73 km² during La Niña in August and October 2018. Heat concentration areas remained consistent during the 1998 El Niño (89.32 km²) and the 2011 La Niña (55.82 km²). These findings highlight ENSO’s influence on altering hotspot distribution patterns. The increased hotspot area during El Niño events (34-36 km²) led to a 20-30% surge in electricity consumption as residents and offices in Kuching City, Sarawak, sought temperature regulation. This spatial information aids the government in identifying affected areas and implementing suitable measures to mitigate the impact of El Niño events.
Coprecipitation Synthesis and Antimicrobial Effect Study of Europium Doped Spinel Manganese Ferrites Nanoparticles (MnEu0.1Fe1.9O4NPs) Amina Chidouh; Tarek Tahraoui; Badra Barhouchi
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.2023.8.3.494-500

Abstract

Due to the high prevalence of micro-organisms resistant to conventional antimicrobials, the search for new antimicrobial drugs is underway, with nanoparticles being one of the options. This study reports for the first time the use of the coprecipitation method to synthesize europium (Eu) doped spinel manganese ferrites nanoparticles (MnEu0.1Fe1.9O4NPs). The purpose of this research is to determine the antimicrobial activity of MnEu0.1Fe1.9O4NPs. MnEu0.1Fe1.9O4NPs were analyzed using Fourier Transform Infrared Spectroscopy (FTIR), X Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-Ray Analysis (EDX) to determine their structure, size, morphology and elemental compositions. The antimicrobial activity of synthesized nanoparticles was evaluated qualitatively using a diffusion disc on agar, followed by minimum inhibitory concentrations (MIC) determination. The findings show that all tested strains were adversely affected by the examined NPs, where E. coli exhibited the highest sensitivity to NPs, followed by S. aureus. The NPs displayed a moderate level of anti-candida action. MnEu0.1Fe1.9O4NPs could be exploited in biomedical usages.

Page 26 of 56 | Total Record : 551

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