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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 24 Documents
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Search results for , issue "Vol. 9 No. 1 (2024): January" : 24 Documents clear
Kinetics of Homogeneous Reaction of Potassium Methoxide Based on K2CO3 Catalyst in Transesterification of RBDPO to Biodiesel Salam, Yosirham Abdu; Komariah, Leily Nurul; Hadiah, Fitri; Arita, Susila
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.28-35

Abstract

Biodiesel production is generally catalyzed by potassium methylate or sodium methylate catalysts based on KOH and NaOH and these catalysts are still imported. The search for a cheap and effective catalyst continues to be carried out by researchers. One of the catalyst support materials currently in use involves impregnating K2CO3 with various substances, resulting in a heterogeneous catalyst. In this study, it was tried to use K2CO3 dissolved in methanol to produce a homogeneous potassium methylate catalyst. Potassium methylate-based homogeneous catalyst K2CO3-methanol is proven to have a very high function in the transesterification reaction of Refined Bleached Deodorized Palm Oil (RBDPO) into biodiesel, this is evidenced by the use of a catalyst percentage of 2% w and 30% w methanol to the weight of RBDPO resulting in an acid content in biodiesel of only 0.12% and a total glycerol of 0.124% in reaction time 3 hours, with the purity of the methyl ester in biodiesel reaching 98.80%. Meanwhile, for the calculation of homogeneous reaction kinetics, a reaction rate equation is produced where the order of the RBDPO transesterification reaction is order 2 (two) and the reaction rate constant is 0.0044.
Antioxidant and Antibacterial Activity of Endophytic Fungi Isolated from Fruit of Sungkai (Peronema canescens) Oktiansyah, Rian; Widjajanti, Hary; Setiawan, Arum; Elfita
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.17-27

Abstract

Peronema canescens, often known as sungkai, is widely used and can be found all around Indonesia. The public believes that the leaves may reduce fever and strengthen the immune system. However, the effectiveness of sungkai fruit has not been thoroughly investigated. In this research, we looked at endophytic fungus extracts from sungkai fruit’s that have antioxidant and antibacterial properties. The study’s results will serve as the foundation for further investigation into the development of potential natural chemicals with antioxidant and antibacterial properties. Morphologically, the endophytic fungi isolated from sungkai fruit were identified. The antioxidant and antibacterial properties of endophytic fungal extracts were studied using the DPPH technique and the paper disk diffusion method. By employing molecular identification and column chromatography to separate the active compounds, the most likely endophytic fungal isolates were found based on the results of the bioactivity tests. Using 1D NMR spectroscopic methods, the chemical’s structure was determined, and the results were compared to NMR data for the same compound published in the literature. Fruit of sungkai had 8 strains of endophytic fungus (RBH1-RBH8). Strong antibacterial and very strong antioxidant activity were shown by the RBH5 isolate (IC50 < 20 μg/mL). Pythium periplocum was determined to be the RBH5 isolate based on molecular testing. Pure chemical compound extracted from RBH5 isolates shown highly potent and potent antibacterial and antioxidant effects. The chemical compound was identified by spectroscopy as 3-hydroxy-4(hydroxy(4-hydroxyphenyl)methyl)-γ-butyrolactone. The results of this study serve as the foundation for developing compounds as pharmaceutical raw materials via further research phases.
Tridiagonal Interval Matrix: Exploring New Perspectives and Application Thirupathi, Sivakumar; Thamaraiselvan, Nirmala
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.77-85

Abstract

Tridiagonal interval matrices are relevant in diverse applications, especially in dealing with parameter estimation, optimization and circuit analysis uncertainties. This research paper aims to improve the computational efficiency of obtaining the inverse of a general tridiagonal interval matrix. This matrix is pivotal in electric circuit analysis. We achieve this by employing interval arithmetic operations in the LU decomposition process, enabling effective handling of circuit parameter uncertainties. This approach generates an inverse interval matrix that addresses uncertainties in circuit analyses.
Enhanced Efficiency for Biogas Production from Distillery Wastewater as Mixed with Molasses and Glycerol Waste in the Anaerobic Co-Digestion Rattanadilok Na Phuket, Kiattisak; Srimachai, Tussanee; Luanunkarb, Saowarod; O-Thong, Sompong
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.120-128

Abstract

This experiment was conducted to decide the impact of molasses and glycerol waste on upgraded methane production in anaerobic co-digestion with distillery wastewater. Co substrates used for biogas production in the anaerobic co-fermentation process of distillery wastewater (DW) were molasses (ML) and glycerol waste (GW). The co-substrate concentration in all batch experiments varied between 1% and 5% (v/v). To study the efficiency of biogas production, the optimal ratio was chosen for operation in the PFR continuous reactor. Optimization results indicated that anaerobic co-digestion of DW with 5% GW and 1% ML could improve biogas quality and quantity. HRT for 30 days allowed R2 (95% DW: 5% GW) to produce maximum methane production per 11 m3 CH4/m3 mixed wastewater, followed by R1 (99% DW: 1%). ML) 6 m3 CH4/m3 mixed wastewater and control (100% DW) could only produce 2.7 m3 CH4/m3 mixed wastewater methane. As co-substrates, GW and ML can be balanced to coordinate the C/N ratio and pH of DW. In particular, the C/N ratio of the mixed sewage can be balanced, and the concentration of ammonia nitrogen within an anaerobic digestion tank can be diluted. Therefore, GW can be used as an optimal co-substrate as it improves the C/N ratio, dilutes toxic compounds within DW, and provides lower prices, thus increasing the potential for methanogenesis within DW affected to increase biogas production.
Combination Effect of Extracts and Pure Compounds of Endophytic Fungi Isolated from Sungkai (Peronema canescens) Leaves on Antioxidant Activity Elfita; Oktiansyah, Rian; Mardiyanto; Setiawan, Arum; Widjajanti, Hary
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.69-76

Abstract

Endophytic fungi extracts have various biological and pharmacological activities as natural antioxidants which have the potential to be developed in the pharmaceutical. Drugs made from natural substances frequently work best when they are present in large quantities. This may result in unfavorable side effects from using more of one substance at a time. This limitation can be overcome by using a combination of the extracts/pure compounds that allow synergistic interactions with strong antioxidant properties at fairly low concentrations. The purpose of this research was to determine the combined effect of endophytic fungi extracts and its pure compounds on their antioxidant activity. This research was initiated by rejuvenating eight selected endophytic fungal isolates from Sungkai leaves and morphological characterization was carried out. Each fungus was cultivated in PDB medium for 4 weeks under statistical conditions. Ethyl acetate was used to extract the endophytic fungi’s liquid culture, which was then evaporated. Each endophytic fungal extract (PD1-PD8) and their five pure compounds were tested for antioxidant activity by the DPPH method. Then a combination of two and three extracts was carried out with a ratio of 1:1. The results show that the interaction of the mixture of endophytic fungi extracts and their pure compounds can be classified as synergistic (combined effect of the extracts > individual effects), additive (combined effect of the extracts = individual effect), and nothing is antagonistic (combined effect of the extracts < individual effects). The best combination in this study was PD4+PD5+PD6 (1:1:1) which could be used as a formula for further research into in vivo immunostimulant tests. Another conclusion from this research is that the pure compounds contained in the extracts have lower antioxidant activity than the extracts and do not have a synergistic effect on the combination.
Synthesis, Corrosion Inhibition Efficiency in Acidic Media, and Quantum Chemical Studies of Some Hydrazine Derivatives Abood, Huda Saleh; Jasim, Ekhlas Qanber; Muhammad-Ali, Munther Abduljaleel
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.137-147

Abstract

In this work, four hydrazone Schiff base derivatives N-(2,4-Dinitro-phenyl)-N’-(1H-pyrrol-2-ylmethylene)-hydrazine (1a), N-Benzo [1,3] dioxol-5-ylmethylene-N’-(2,4-dinitro-phenyl)-hydrazine (1b), (E)-5-((2-(2,4-dinitrophenyl)hydrazono)methyl)-2-hydroxybenzoic acid (1c) and (E)-1-(2,4-dinitrophenyl)-2-(2-methoxybenzylidene)hydrazine (1d) were synthesized by reaction of four aldehydes namely pyrrole-2-carboxaldehyde, piperonal, 5-formylsalicylic acid, and o-vanillin with 2,4-dinitrophenyl hydrazine to produce the final compounds 1a, 1b, 1c, and 1d, respectively. These four compounds were investigated as corrosion inhibitors in aqueous mild acidic static solution. FTIR, HNMR, and elemental analysis were used to elucidate the chemical structure of the synthesized inhibitors. Using potential dynamic polarization measurements, these inhibitors’ efficiency in preventing C-steel corrosion in 1.00 M HCl was studied. The results of the experiments revealed that 1×10−3 M is the ideal concentration for 1a, 1b, 1c, and 1d, and that the corresponding inhibition efficiencies for these subunits were 80.70%, 91.30%, 91.34, and 88.80%, respectively. The best corrosion inhibitors were compounds 1b and 1c. Furthermore, studies suggested that these substances are mixed-type inhibitors and that the efficiency of the inhibition is strongly correlated with their quantity. Quantum paraments included Dipole moment, energy band gap (ΔE), value of energy of lowermost unoccupied molecular orbital (ELUMO), and energy of high most occupied molecular orbital (EHOMO) using Molecular Operating Environment MOE, Gaussian, and HyperChem software packages were determined which demonstrated strong agreement between algorithmic and practical findings.
Synthesis and Characterization of CuO and NiO Nanoparticles Derived from Schiff Base Complexes Bader, Ali Taleb; Al-qasii, Nada Ahmed Rasheed; Khaleel, Asmaa Mohammed Noori
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.103-112

Abstract

This study reports the synthesizes of such as copper oxide (CuO) and nickel oxide (NiO) nanoparticles (NPs) by thermal decompositions of Schiff base complexes and their physical characterization. A polydentate Schiff base ligand, (E)-2-(((2-chlorobenzyl)imino)methyl)phenol (CIMP), was synthesized by condensing 2-chlorobenzylamine and 2-hydroxybenzaldehyde. The ligand was identified by melting point, FT-IR, UV-Vis, and (1H and 13C NMR) spectroscopy. Cu(II) and Ni(II) complexes were prepared by reacting CIMP with the corresponding molar ratio in a 1:1 (metal: ligand). The complexes (Com1 and Com2) were characterized by melting point, FT-IR, and UV-Vis spectroscopy. The FT-IR spectra of the (Com1 and Com2) showed that the deprotonated CIMP ligand coordinated to the Ni(II) and Cu(II) metal ions through the azomethine nitrogen, aryl chloride, chlorine, and phenolic oxygen atoms. To determine the crystalline structure of the synthesized products, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed. The formation of copper oxide and nickel oxide as the new products was confirmed by XRD analysis. SEM imaging revealed the uniform and spherical morphology of the nanoparticles, which exhibited a remarkably narrow size distribution with an average diameter of 20 to 22 nm, highlighting their exceptional precision
Sodium Methoxide Catalyzed Preparation of Nitrogen Compounds from Palm Oil Methyl Esters as Corrosion Inhibitor Ilim; Hidayah, Laila; Yuliyanda, Devi; Delilawati Pandiangan, Kamisah; Simanjuntak, Wasinton
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.113-119

Abstract

This research was conducted to study preparation of nitrogen compounds by reacting palm oil derived methyl esters and diethanolamine using sodium methoxide as a catalyst. The chemical composition of the product was analyzed using the gas chromatography-mass spectrometry (GC-MS) method. The product was then applied as a corrosion inhibitor for mild steel in CO2 saturated 3% NaCl solution. Experimental results indicate that the reaction product contains six nitrogen compounds with a relative percentage of 63.7%, and the rest 36.7% are a mixture of unreacted diethanolamine and unreacted methyl esters. The results of the corrosion experiments show that the product obtained exhibited appreciably high performance as reflected by a percentage of protection (%P) of 96.85%. The performance of the product as a corrosion inhibitor is also supported by the SEM image of the mild steel sample, which shows that the surface of the sample is well protected. The results of this work demonstrate that nitrogen compounds obtained have promising potential as corrosion inhibitors, particularly to prevent corrosion by CO2 gas.
Inventory Model for Deteriorating Pharmaceutical Items with Linear Demand Rate Indrawati; Puspita, Fitri Maya; Supadi, Siti Suzlin; Yuliza, Evi; Rizki, Krisda
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.148-155

Abstract

Good management of goods is needed so that the inventory activities of a business can run smoothly as the part of supply chain management which aims to monitor the flow of stock of goods from the purchasing process, and storage to the point of sale. In terms of inventory or supplies of pharmaceutical goods, conditions such as shortages or stockouts must also be considered which are a matter of control, management, and security. In this study, an inventory model is formulated with deterioration or damage to pharmaceutical goods that occurs due to the length of time when the goods are stored with a linear demand level. In the optimal solution, the inventory time occurs when it reaches the zero point (t1) of 0.34 and the cycle length (T1) of 0.83 with an average minimum total cost (TC) of $445.25 per cycle which is completed by WolframAlpha software. Sensitivity analysis changes the value results in the value of (TC) which that increases for all parameters. In increasing the linear function variables (a and b), it produces t1 and T1 stable values. An increase in the cost of each item damage (DC) and constant damage rate (theta) produces a t1 stable value, but the value of T1 increases. The increase in storage costs (h) results in a decrease in the value of t1 and T1. An increase in the cost of shortages (s) results in an increase in the value of t1 and a decrease in the value of T1.
Carbon Dots-based Antifungal Coating Film Against Pathogens Colletotrichum sp. for Active Coating Application of Mango Safitri, Idayu; Sugiarti, Sri; Darmawan, Noviyan
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.173-182

Abstract

Mangos are one of horticultural products that are leading the Indonesian agricultural industry. Simple post-harvest handling leads to high damage. The most common causes is anthracnose disease caused by Colletotrichum sp. Therefore, it’s necessary to modify the existing methods in postharvest handling such as coating. Adding active agents such as carbon dot (CD) in coating material to prevent anthracnose from growing and shorten the shelf life. This study aims to investigate the applicability and antifungal properties of CD as a composite coating. CDs were synthesized using chitosan as the carbon source in a one-pot hydrothermal technique. The CDs have blue-emitting luminescence caused by the functional group at the surface of CD. The CDs were used to prepare chitosan/pectin (Chi/Pec)-based composite coatings. The addition of CDs increased the viscosity and density of composites, increased the blue-emitting luminescence, and showed potential antioxidant activity. The CDs and composite coatings exhibited high antifungal activity against Colletotrichum sp. by agar well diffusion method and were classified as very strong antifungal agents. The chitosan/pectin/CDs-coating effectively reduced the growth of black spots on the surface of mangos and increased the fruit shelf life of the fruit by 24 days. The CDs are evidently safe, affordable, and value-added nanomaterials that can be used to prepare active packaging applications.

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