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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 Production of Renewable Fuels Sago Dregs and Low-Density Polyethylene by Pyrolysis and its Characterization Jahiding, M; Mashuni, Mashuni; Handayani Hamid, Fitri; Sitti Ilmawati, Wa Ode; Hamdana, Renaldi
Science and Technology Indonesia Vol. 9 No. 3 (2024): 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.2024.9.3.565-576

Abstract

Biomass has been suggested as a sustainable alternative to substitute fossil fuels. Based on the pyrolysis method, the biomass would be converted into energy through decomposition by thermal degradation under an inert atmosphere, resulting in charcoal, liquid, and gas products. The quality of oils is effectively enhanced through the pyrolysis of lignocellulosic biomass and plastic due to the facilitation of deoxygenation by plastics. This study investigates the impact of incorporating low-density polyethylene (LDPE) plastic in co-pyrolysis with sago dregs (SDs) waste. Pyrolysis of SDs and LDPE mixtures with ratios of 5:1, 4:2, 3:3, 2:4, and 1:5 at various temperatures of 375°C, 425°C, and 475°C. The maximum oil yield obtained for SDs and LDPE pyrolysis was 44.94%. The calorific value (CV) of all observed compositions is a minimum of 10,579.57 kcal kg-1 and a maximum of 11,545.21 kcal kg-1. The gas chromatography-mass spectroscopy (GC-MS) analysis confirmed the interaction between SDs and LDPE on co-pyrolysis. The addition of LDPE will produce rich aliphatic and aromatic compounds, like the proportions of alkanes (45.53%), alkenes (30.62%), alcohol (0.4%), and benzene (17.68%). Co-pyrolysis of SDs and LDPE promotes enhanced oil production by reducing oxygenated compounds and increasing hydrocarbon compounds.
Formulation and Evaluation of Gambier (Uncaria gambir)-Chitosan Microparticle Intranasal Delivery for Alzheimer’s Diseases Fithri, Najma Annuria; Mardiyanto; Fitrya; Rahmah, Asfaraeni; Annisa, Novilia Megi
Science and Technology Indonesia Vol. 9 No. 2 (2024): 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.2024.9.2.284-298

Abstract

Alzheimer’s Disease (AD), the most common form of dementia continues to be the deadliest neuro degenerative disease in recent years. Despite significant efforts to mitigate the progression of the disease, there is no known cure and development towards a more effective treatment is still lacking. AD is marked by exceptionally low amount of acetylcholine in the brain, formation of tau protein, and amyloid beta plaque. Current drugs of choice for treating AD, namely donepezil and memantine, are acetylcholinesterase (AChE) inhibitors which focused on delaying the onset of cognitive decline by maintaining acetylcholine concentration. Gambier water extract (GWE) contains high level of polyphenols which act as an antioxidant, exhibit strong correlation with AChE inhibitor. The aim of this research is to formulate and encapsulate GWE inside a microparticle system composed of chitosan and different crosslinkers, STPP (IMGS) and CaCl2 (IMGC), which were then characterized as AChE inhibitor using Ellman’s method. Variations of the formula were designed following Box-Behnken experimental design with chitosan and crosslinker concentration, crosslinker type, and stirring speed as variables. Initial activity of GWE, IMGS and IMGC as antioxidant were confirmed with DPPH method, obtaining a strong activity of 88.01, 82.11, and 84.99% DPPH inhibition at 100 ppm respectively. Promisingly, at concentration of 100 ppm GWE demonstrated AChE inhibition of 30.36%. However, this activity reduced after encapsulation into IMGS and IMGC, with 14.63% and 18.65% AChE inhibition, which can be linked to the relatively sustained diffusion of GWE from the polymer matrix. IMGS and IMGC diffusion profile showed release of 23.24% and 21.89% after 6 hours, with significant increase in diffusion after 24 hours with 74.92% and 71.19% respectively. Despite showing sustained release behaviour, both IMGS and IMGC ex-vivo diffusion significantly improved when compared to GWE which only diffused 51.84% after 24 hours. This result indicates encapsulation of GWE into a polymeric carrier could increase gambier diffusion through the nasal mucous membrane, significantly improving the potential to penetrate into the brain systemic circulation. Combined with desirable intranasal delivery characteristics, this research was able to demonstrate the promising potential of gambier water extract polymeric system as AChE inhibitors for AD therapy.
Anti-Inflammatory Activity and Phytochemical Profile from the Leaves of the Mangrove Sonneratia caseolaris (L.) Engl. for Future Drug Discovery Rozirwan; Ade Siswanto; Nadila Nur Khotimah; Redho Yoga Nugroho; Wike Ayu Eka Putri; Fauziyah; Rezi Apri; Hartoni
Science and Technology Indonesia Vol. 9 No. 2 (2024): 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.2024.9.2.502-516

Abstract

The increasing demand for effective and natural anti-inflammatory agents prompts an investigation into the properties of Sonneratia caseolaris (L.) Engl., a plant traditionally used in medicine. This study aimed to explore the ability of S. caseolaris leaves extract to inhibit inflammation and accelerate wound healing. S. caseolaris leaves were collected from Tanjung Api-Api area, Banyuasin, South Sumatra. The method involved carrageenan induction in rat paws as an inflammatory model. The results showed that the most effective dose was found in the group with a dose of 150 mg/kg BW measured using a digital caliper and plethysmometer. The qualitative phytochemical test contain alkaloids, steroids, flavonoids, and phenols. The results GC-MS analysis were thought to contain aldehydes, glucosinolates, coumarins, esters, terpenoids, alcohols, lipids, tocopherols, and steroids. Due to their diverse range of mechanisms of action, coumarins show significant promise in mitigating inflammation and hold potential for treating inflammatory conditions. This study provides new insights related to the potential of S. caseolaris as a source of natural anti-inflammatory agents, supporting public comprehension regarding the utilization of traditional herbal remedies.
Synthesis and Characterization of Perovskite Manganate Based on La0.7Ca0.3MnO3 with Ni and Ti doping as Microwave Absorber Material Saptari, Sitti Ahmiatri; Mar’ah, Mufidatul; Taryana, Yana; Sudrajat, Nanang
Science and Technology Indonesia Vol. 9 No. 3 (2024): 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.2024.9.3.577-585

Abstract

Research has been carried out on the effect of Ni and Ti doping on the microwave absorption properties of the perovskite manganate material La0.7Ca0.3Mn1-xNix/2Tix/2O3 (LCMNTO) with variations x = 0; 0.03; 0.05; and 0.1, which were synthesized by the sol-gel method. The effect of Ni and Ti doping on the structure, grain size, magnetic properties, and microwave absorption properties were investigated in detail by various analytical methods. XRD (x-ray diffraction) characterization showed that the material La0.7Ca0.3Mn1-xNix/2Tix/2O3 has a single phase with an orthorhombic crystal system. The SEM (scanning electron microscope) results showed a tendency to decrease in grain size when the composition of Ni and Ti dopants began to increase. VSM (vibrating sample magnetometer) characterization shows that La0.7Ca0.3Mn1-xNix/2Tix/2O3 is a soft magnet with magnetic properties that decrease with increasing Ni and Ti dopant composition. The characterization of VNA (vector network analyzer) in the 8-12 GHz shows that the highest ability to absorb microwaves is 98% at 8.24 GHz, and there is an addition of absorption areas point and widening of the absorption bandwidth. Thus, the material La0.7Ca0.3Mn1-xNix/2Tix/2O3 has the potential to become a microwave absorber material.
Incorporating q-Rung Picture Fuzzy Frank Prioritized Weighted Aggregators with Multimoora Strategy for Decision Making Ramesh, Chitra; Kesavan, Prabakaran
Science and Technology Indonesia Vol. 9 No. 4 (2024): 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.2024.9.4.766-778

Abstract

The Frank norm operators and ˇq-rung picture fuzzy sets offer a versatile framework due to their adjustable parameters. Conversely, prioritized weighted operators are crucial for indicating the relative significance of alternatives and attributes. In this research, we have devised Frank’s prioritized weighted procedure for ˇq-rung picture fuzzy numbers. Thus, the ˇq-rung picture fuzzy prioritized weighted Frank averaging (ˇq-RPFPWFA) and geometric (ˇq-RPFPWFG) operators are presented and analyzed along with some of their properties. Utilizing these proposed operators, a novel approach is established, combining the enhanced MULTIMOORA (MM) procedure with unspecified weight data. A numerical example regarding the multiple attribute group decision making (MAGDM) problem of selecting the financial director of a residential society is handled based upon the aforementioned procedure. Furthermore, we have compared the results with those obtained using available operators. Evidently, the novel ˇq-RPFPWFA and ˇq-RPFPWFG aggregators with the MM technique yield reasonable and consistent outcomes for solving MAGDM.
The Influence of Catalyst Loading on Electrocatalytic Activity and Hydrogen Production in PEM Water Electrolysis Rohendi, Dedi; Amelia, Icha; Sya'baniah, Nyimas Febrika; Yulianti, Dwi Hawa; Syarif, Nirwan; Rachmat, Addy; Fatmawati; Majlan, Edy Herianto
Science and Technology Indonesia Vol. 9 No. 3 (2024): 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.2024.9.3.556-564

Abstract

The climate change caused by the widespread and continuous use of fossil fuels is a problem that needs to be addressed urgently. One of the solutions offered is through an energy transition towards the use of new or renewable and low-carbon fuels. Hydrogen gas as a carrier of energy is an alternative solution that has attracted the attention of researchers, due to its high combustion energy and environmental friendliness. The production of hydrogen gas using the Proton Exchange Membrane Water Electrolysis (PEMWE) method is considered effective for large-scale production. This study investigates the impact of catalyst loading and various current densities on hydrogen production in the PEM water electrolysis process, utilizing the Cu2O/C catalyst. This study investigates the impact of catalyst loading and different current densities on hydrogen production in the PEM water electrolysis process, utilizing the Cu2O/C catalyst. The electrode catalytic properties were evaluated using the Cyclic Voltammetry (CV) method to determine the Electrochemical Surface Area (ECSA) and the Electrochemical Impedance Spectroscopy (EIS) method to determine the electrical conductivity. The ECSA and EIS measurements demonstrated that the best results were obtained at a higher catalyst loading of 2 mg/cm2 with an ECSA value of 0.21 m2/g and electrical conductivity of 3.04 × 10−6 S/cm. The production of hydrogen results showed that the highest hydrogen production rate was 3.75 mL/s with a catalyst loading of 2.5 mg/cm2, indicating that increasing the load could lead to a higher rate of hydrogen gas production, but this is highly dependent on the surface area utilized. Additionally, at higher current densities, the cell resistance in the electrolysis process may decrease, leading to reduced electrode efficiency for hydrogen production. Thus, the use of high currents may not always be advantageous in hydrogen production using the PEM water electrolysis method.
New Encapsulation of Fucoxanthin Isolated from Cyclotella striata by Nano Chitosan–Pectin using Ionic Gelation Method Nahrowi, Ridho; Solehati, Siti; Widyastuti, Widyastuti; Juliasih, Ni Luh Gede Ratna; Pandiangan, Kamisah Delilawati; Setiawan, Andi; Hendri, John
Science and Technology Indonesia Vol. 9 No. 3 (2024): 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.2024.9.3.517-528

Abstract

Fucoxanthin is an anticancer, antioxidant, antimicrobial, and anti-inflammatory bioactive compound. Unfortunately, the conjugated double bonds of the fucoxanthin structure make it unstable, posing issues for product development, particularly with regard to shelf life. This research study aims to synthesize nano chitosan–pectin and encapsulate isolated fucoxanthin by nano chitosan–pectin using an ionic gelation method. Fucoxanthin was obtained through isolation of microalgae species Cyclotella striata. The best result of nanoparticle size using a particle size analyzer was chitosan:pectin 1 : 2 of 172 nm. Fourier transform infrared analysis showed that there was an interaction between chitosan–pectin and fucoxanthin, which was characterized by a shift in the C O absorption fucoxanthin from 1736 to 1632 cm-1. The result of morphological analysis of nano chitosan–pectin–fucoxanthin using a scanning electron microscopeshows a spherical morphology with a size between 140 and 265 nm. The result of encapsulation efficiency was 75.18%, whereas encapsulation stability increased fucoxanthin oxidation half-life 4.7 times longer than that of unencapsulated fucoxanthin. The nano chitosan pectin could be utilized as a matrix conjugate to increase the stability of fucoxanthin significantly by encapsulation. This information is expected to be useful in developing encapsulation applications for unstable compounds.
ZnAl LDH-based Derivative Materials as Photocatalysts: Synthesis, Characterization, and Catalytic Performance in Tetracycline Degradation Rohmatullaili; Ahmad, Nur; Erviana, Desti; Zultriana; Savira, Dila; Mohadi, Risfidian; Lesbani, Aldes
Science and Technology Indonesia Vol. 9 No. 2 (2024): 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.2024.9.2.457-469

Abstract

Layered Double Hydroxide (LDH)-derived materials exhibited different characteristics from LDH precursors. The conversion of ZnAl LDH into its derivative material has been carried out to find the best catalyst for TC degradation. ZnAl (LDH)-based catalysts in this study have been effectively synthesized using coprecipitation, calcination, and restacking procedures. ZnAl Layered Double Oxide (LDO) is derived from the calcination of ZnAl LDH at 500°C. ZnAl LDH was also modified by adding Garcinia mangostana pericarp extract (GME). XRD, FT-IR, UV-DRS, and SEM-EDX were used to investigate the synthesized catalyst. ZnAl LDH exhibited the typical LDH FT-IR spectra, whereas ZnAl LDO showed metal oxide-like spectra, and the ZnAl-GME composite displayed the combination spectra of precursor material. The ZnAl LDH XRD diffraction pattern exhibited the attributes of a layered material, whereas the other three catalysts did not. Calcination destroyed the layered structure of ZnAl LDH, whereas the addition of GME to LDH and LDO generated a single-layered composite. The modified ZnAl-GME composite showed a decrease in both particle size and bandgap energy. At an ideal pH of 5, the synthesized catalyst was used in a batch system photodegradation of 5 mg/L Tetracycline (TC), employing solar light irradiation. ZnAl LDO holds the most significant catalytic activity and structural stability through the fifth regeneration cycle, degraded TC up to 100% in 90 minutes.
Application of KBaYSi2O7:Bi3+,Eu3+ Phosphor for White Light-Emitting Diodes with Excellent Color Quality Loan, Nguyen Thi Phuong; Thuy, Le Xuan; Thai, Nguyen Le; Lee, Hsiao Yi; Cong, Pham Hong
Science and Technology Indonesia Vol. 9 No. 3 (2024): 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.2024.9.3.756-765

Abstract

This paper examines the properties of two phosphor materials synthesized via utilizing the sol gel method: KBaYSi2O7:Bi3+ (KBYS:Bi) phosphor providing cyan/deep-blue emission and KBaYSi2O7:Bi3+,Eu3+ (KBYS:Bi,Eu) phosphor exhibiting tunable emission from near-UV to red. The optimal doping concentrations for Bi3+ and Eu3+ are 0.2% and 3.5%, respectively. It is found that the ability to give discrepant emission peaks under different excitation sources of the KBYS:Bi phosphor is attributed to the occupancy of Bi3+ in different cation hosts. Meanwhile, co doping the Eu3+ and Bi3+ into the KBYS host leads to red and cyan emission regions, enabling the emission tunability of the KBYS:Bi,Eu phosphor. KBYS:Bi,Eu phosphor was then used in combination with YAG:Ce3+ and blue chips to fabricate a white light emitting diode (LED) model. The particle sizes of KBYS:Bi,Eu phosphor are adjusted to examine its influences on the LED properties. With increasing particle sizes (≥12 µm), the KBYS:Bi,Eu phosphor can improve the scatter efficacy, transmission power, lumen output, and color performance (rendition and uniformity). Both KBYS:Bi and KBYS:Bi,Eu phosphors are promising luminescent phosphors that can be combined with other phosphor with different emission colors to obtain the full-spectrum or tunable white light for LEDs.
Modelling of Claim and Pricing of Motor Insurance Based on Bonus-Malus System Considering the Frequency and Severity of Claims Hengcharoensuk, Jiramet; Phanmai, Konlawat; Moumeesri, Adisak
Science and Technology Indonesia Vol. 9 No. 4 (2024): 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.2024.9.4.904-913

Abstract

This article proposes new distributions for claim frequency and severity, specifically tailored for a bonus-malus system in automobile insurance. The mixed Poisson with weighted quasi Lindley distribution is recommended for modeling claim frequency, while the mixed exponential with weighted quasi Lindley distribution is suggested for modeling claim severity. To estimate insurance premiums, the Bayesian method is employed, incorporating both frequency and severity distributions. The study validates the proposed models using real data from an Australian insurance company, which includes 67,856 policies. The assessment of model adequacy indicates that the Poisson-weighted quasi Lindley distribution is a suitable fit for modeling claim frequency, while the exponential-weighted quasi Lindley distribution is appropriate for modeling claim severity. Overall, the results suggest that the proposed models offer optimal premium estimations, considering both claim frequency and severity, which can lead to fairer pricing and increased customer appeal during claim occurrences compared to conventional models.

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