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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 21 Documents
Search results for , issue "Vol. 8 No. 1 (2023): January" : 21 Documents clear
Photoprotective and Antioxidant Potential of Indonesia’s Klanceng Honey Beehive Waste Yuliana Purwaningsih; Ahmad Fuad Masduqi; Erwin Indriyanti; Mighfar Syukur
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.137-143

Abstract

A byproduct of the honey processing called Klanceng honey beehive waste is said to still contain secondary metabolites that are beneficial to health. The objective of this research was to assess the photoprotective properties of an ethanol extract, n-hexane fraction, and ethyl acetate fraction obtained from the waste of an Indonesian Klanceng honey beehive that originated in Magelang. The DPPH free radical technique was applied to quantify antioxidant properties, and the Mansur equation’s SPF value was used to calculate photoprotective activity. The analysis of the data revealed that the IC50 values for the ethanol extract, n-hexane fraction, and ethyl acetate fraction were, respectively, 470.2935±0.9249, 207.1869± 2.6510, and 216.4892±0.8349. The ethanol extract, n-hexane fraction, and ethyl acetate fraction of the samples had SPF values of 3.872, 3.529, and 9.358, respectively. The ethyl acetate fraction, as opposed to the ethanol extract and the n-hexane fraction, has greater potential as a photoprotective agent as a result.
A Multi-Period Model for Optimal Changi Airport Check-In Counter Operations Nur Haliza Md Alimuddin; Qatrunnada Noor Izzuddin; Muhammad Amirul Amat; Zati Aqmar Zaharudin
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.116-122

Abstract

Growth in air passenger flow has caused severe congestion at the airport check-in counter, posing a significant problem for airport management. Particularly during the check-in process, the necessary authorities must coordinate sufficient facilities with adequate staffing levels. The airport check-in counter problem (ACCAP) is a field concerned with establishing the optimal number of check-in counters to balance operating expenses and passenger wait times in order to reduce airport congestion. Expanding the number of counters and staff to a minimum operating cost is able to prevent the congestion problem from escalating without incurring further operating expenses. This paper focused on proposing optimal scheduling of airport check-in counters operations, including staffing. A dynamic model with multi-period principles is adapted to address the aforementioned problem by balancing the trade-off between service performance and operational cost. As a case study, data from Singapore Changi International Airport was utilized. The findings are also discussed in terms of the flow of passengers throughout the airport check-in procedure and operations. As a result, the number of activated counters is minimized throughout all shifts by applying the dynamic model at the average service time. At the same time, there are fewer passengers in the queue.
Analysis Multivariate Time Series Using State Space Model for Forecasting Inflation in Some Sectors of Economy in Indonesia Edwin Russel; Wamiliana Wamiliana; Warsono; Nairobi; Mustofa Usman; Faiz AM Elfaki
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.144-150

Abstract

Many analytical methods can be utilized for multivariate time series modeling. One of the analytical models for modeling time series data with multiple variables is the State Space Model. The data to be analyzed in this study is inflation data from expenditure groups such as processed foods, beverages, cigarettes, and tobacco; and housing inflation for water, electricity, gas, and fuel from January 2001 to December 2021. The aim is to determine the best State Space Model that fits the data for forecasting. In this study, the State Space method will be utilized further with multivariate time series data and represent State Space in Vector Autoregressive (VAR) to determine the relationship between groups of observed variables.
Photocatalytic Degradation of Rhodamine-B by Ni/Zn LDH Intercalated Polyoxometalate Compound Yulizah Hanifah; Risfidian Mohadi; Mardiyanto; Aldes Lesbani
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.93-99

Abstract

NiAl-LDH and ZnAl-LDH intercalated polyoxometalate K4 [SiW12O40] and K3 [PW12O40] were synthesized to form composite NiAl-[SiW12O40], NiAl-[PW12O40], ZnAl-[SiW12O40], and ZnAl-[PW12O40]. The physicochemical properties of the materials were characterized by XRD, FTIR, SEM, and UV-DRS. The material used for degraded Rhodamine B (RhB) as a cation dye. The results successfully synthesized by showed the peak diffractions angles at 11.63°, 23.13°, and 35.16° for NiAl-LDH and diffractions at 10.39°, 20.17°, 34.6° and 60.52°for ZnAl-LDH. The LDH typical structure of the composite materials NiAl-[SiW12O40] and NiAl-[PW12O40] was demonstrated by apparent diffraction at 2???? angles of 10.76°, 26.59°, 30.8°, and 63.11° for NiAl [PW12O40], 2???? angles at 8.26°, 11.34°, 29°, and 35.1° for NiAl-[SiW12O40], 7.73°, 28.6° and 35.6° for ZnAl-[PW12O40], and 8.61°, 25.27°, 34.96° and 66.34° for ZnAl-[SiW12O40]. The materials were characterized as an advanced catalyst to improve photocatalytic activity for RhB elimination under visible light sources. The intercalation of polyoxometalate [SiW12O40]4- and [PW12O40]3- into LDH could enhance the degradation cationic dye of RhB. Intercalation improved the photodegradation performance determined under UV-Vis irradiation conditions which composite NiAl-LDH was better than ZnAl-LDH composite. It was present by the %degradation RhB performances NiAl-LDH, ZnAl-LDH, NiAl-[SiW12O40], NiAl-[PW12O40], ZnAl-[SiW12O40], and ZnAl-[PW12O40] were 91.48%, 88.59%, and 88.41%, and 87.87%, respectively. The %degradation for NiAl-LDH and ZnAl-LDH was 68.94% and 65.76%. Recovery and reusability experiment of the catalyst demonstrated by degradation percentage that the LDH intercalated polyoxometalate has a great photocatalytic ability.
Phytochemical, Metabolite Compound, and Antioxidant Activity of Clinacanthus nutans Leaf Extract from Indonesia Nurlaili Susanti; Arifa Mustika; Junaidi Khotib; Roihatul Muti’ah; Maftuchah Rochmanti
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.38-44

Abstract

The antioxidant properties from medicinal plants have protective effects against oxidative stress-linked diseases. Their antioxidant capacities are related to phenolic compounds, including phenols and flavonoids. Clinacanthus nutans, a native to Asia, including Malaysia, Thailand, and Indonesia, are used for treating diabetes and other diseases, but the exploration of the plant in Indonesia is still limited. Therefore, this study aimed to reveal the phytochemical constituents, metabolic compounds, and antioxidant activity of C. nutans extracts. Dried leaf powder was extracted with 70% ethanol and aqueous, each extract was subjected to qualitative phytochemical screening. Subsequently, total phenolic and flavonoid content was calculated using Folin-Ciocalteu and AlCl3 colorimetric assay. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The profiles of phenolic and flavonoid compounds of 70% ethanolic extract were investigated by LC MS/MS. Phytochemical screening showed that the extracts contain phenolic, flavonoid, tannin, and saponin. The total phenolic content of the 70% ethanol and aqueous extract was 4.14±1.9% mgGAE/g and 3.89±3.2% mgGAE/g, respectively. Meanwhile, the total flavonoid content obtained was 0.19±1.0% mgQE/g and 0.03±0.5% mgQE/g for 70% ethanol and aqueous extracts, respectively. Both extracts showed high antioxidant activity, with DPPH IC50 30.57 ????g/mL for 70% ethanol and 37.24 ????g/mL for aqueous extract. LC-MS/MS analysis of 70% ethanol extract revealed 5 phenolic and 3 flavonoid compounds, where DL-glutamic monohydrate and Boesenbergin B were the most dominant based on the percentage of area under the curve. C. nutans originating from Indonesia can be a good source of natural antioxidants because 70% ethanol and aqueous extract show high phytochemical content and antioxidant activity.
The Effects of Reactive Oxygen and Nitrogen Species (RONS) Produced by Surface Dielectric Barrier Discharge (SDBD) Non-Thermal Plasma with Treatment Time and Distance Variations to Kill Escherichia coli Renaldo Apriandi Kasa; Unggul Pundjung Juswono; Dionysius J. D. H. Santjojo
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.45-51

Abstract

Research on the inactivation of Escherichia coli causing diarrheal disease using non-thermal plasma SDBD has been carried out. SDBD is a new technique for non-thermal plasma generation with several advantages: low power generation, comprehensive treatment area coverage, and reducing the potential effects of burning and drying tissue. This study aimed to analyze the effect of treatment time variations, namely 0 as control, 60, 75, 90, 105, and 120 seconds and treatment distance variations of 3, 6, 9, 12, and 15 mm of non-thermal plasma treatment of SDBD on E. coli. The results of the non-thermal plasma SDBD treatment with variations in time and distance showed that the longer the treatment time, the more bacterial cells died. Colony counts decreased to 4.33 x 107 CFU/mL compared to the control, 409 x 107 CFU/mL, with a treatment time variation of 120 seconds, yielding the best treatment results. At the same time, the results of the treatment for variations in the non-thermal plasma distance of SDBD showed that the smaller the treatment distance, the greater the bacterial death rate, with the best treatment results at a 3 mm treatment interval, with colony counts of 8 x 107 CFU/mL, compared to 409 x 107 CFU/mL in control. Based on these results, SDBD non-thermal plasma treatment can be used to inactivate or kill bacteria with effectiveness in killing bacteria depending on the length of treatment time and the distance of treatment.
Bayesian Mixture Statistical Modeling Perspective in the Series of Diabetes Mellitus Disaster Mitigation in Malang Regions Ani Budi Astuti; Nur Iriawan; Suci Astutik; Viera Wardhani; Ari Purwanto Sarwo Prasojo; Tiza Ayu Virania
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.71-83

Abstract

Statistical modeling is one of the most important activities in Statistics in order to simplify complex problems in society, to make it easy, simple, and useful. The perspective of statistical modeling is very useful for society in various fields. Probabilistic-based statistical modeling concept is strongly influenced by the shape of the data distribution, data validity, and data availability. Bayesian concept approach in the statistical modeling has advantages compared to the non-Bayesian approach, which is any sample and any distribution of the data and in this case it often occurs in data in the community. In particular, the Bayesian mixture concept discusses the Bayesian approach with data specifications having a mixture (multimodal) distribution. Diabetes Mellitus (DM) is a disease that is not contagious but the side effects are very dangerous for humans and require large costs to handle. Indonesia ranks seventh in the world for the number of DM sufferers and it is estimated that in 2045, the number of DM sufferers in Indonesia will reach approximately 16.7 million people. Mitigation of DM disease in various regions in Indonesia continues to be pursued, including Malang regions. One of the efforts made is through the statistical modeling perspective of the Bayesian approach which can be used for efforts to control, prevent, treat, and overcome DM. The purpose of the study was to build a suitable Bayesian model for DM cases in Malang regions in order to map the DM case areas in Malang. The results showed that in each district area in the city of Malang it was divided into three groups based on the severity of DM sufferers. The three groups are DM sufferers in the categories of not yet severe, moderate, and severe with the model validation indicator using the smallest Kolmogorov-Smirnov value. Sukun District and Klojen District in the Malang region are two districts that need serious attention from the local government of Malang City in dealing with DM cases. Through the perspective of Bayesian statistical modeling, DM cases in five districts in the Malang area showed a mixture distribution with a different number of mixture components as the basis for regional mapping.
The Addition of Red Dragon Fruit and Lemon Peels for the Improvement of Fermented Beverage Products Sofi Nabila; Arie Srihardyastutie; Sasangka Prasetyawan; Aulanni’am; Rurini Retnowati
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.100-107

Abstract

Coconut water is part of the coconut fruit, that has bioactive compounds that are thought to own high inhibitor activity to the presence of tannin compounds. However, this compound is antinutritional because it can interfere with macromolecule out there within the body. Considering chance of tannins, these parts are often reduced by fermentation techniques using lactic acid bacteria. This analysis aims to review the addition of dragon fruit and lemon peels in fermentation coconut water using lactic acid bacteria in order to reduce tannin levels and its potential capability as antioxidants. Coconut water fermented drink was prepared by fermentation technique using lactic acid bacteria with the addition of variations in mass of dragon fruit peel and lemon peel consisting of 5 treatments. The optimum conditions for fermentation of coconut water were determined from the decrease in tannin levels, total acid, and the highest total lactic acid bacteria. The optimum conditions for fermentation of coconut water were then tested using an HPLC instrument. Finally, the antioxidantactivity was tested using the FRAP (Ferric Reducing Antioxidant Power) method. The results showed that the addition of dragon fruit and lemon peels in fermented coconut water can reduce tannin levels, can increase total acid levels and the number of lactic acid bacteria formed in coconut water fermented drinks. The best proportion was obtained in the treatment of rasio of mass 1:2 resulted in the highest decrease in tannin content of 83.94 mg/100 g followed by a total acid value of 1.13% and the number of lactic acid bacteria was 8.4 × 107 CFU/mL. The HPLC chromatogram showed that fermented coconut water using lactic acid bacteria contained organic acid compounds such as lactic acid, acetic acid, and ascorbic acid. The highest antioxidant activity test was 82.37 mmgAAE/g. This study confirmed that the addition of dragon fruit and lemon peels affected the degradation of tannins and increased antioxidant activity during coconut water fermentation using lactic acid bacteria.
Fe3O4-SiO2-Alginate Photocatalyst for Textile Dyes Waste Degradation Sri Wardhani; Herdian Akbar Mardiansyah; Danar Purwonugroho
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.108-115

Abstract

Fe3O4 is a photocatalyst that is used to degrade textile dye waste which can be collected and reused. Fe3O4 was prepared by coprecipitation method, then impregnated with SiO2 and sodium alginate. The purposes of this study were to investigate the degradation of textile dye waste using a Fe3O4-SiO2-alginate photocatalyst, to examine the light and dark test of photocatalyst under the influence of concentration and irradiation time. The type of light used was a 14.5-watt Philips LED lamp with a wavelength of 400-640 nm. Photocatalyst characterizations were conducted using FTIR, UV-Vis DRS, and XRD. The light and dark test of photocatalyst was carried out by photodegradation of textile dye waste with 0.5 g of photocatalyst with concentrations of 5%, 10%, and 15% and irradiation times were varied for 60, 90, 120 min. The degradation results were measured by calculating the COD value. The results of characterization by FTIR showed that the photocatalyst Fe3O4-SiO2-Alginate had absorption at wavelengths of 637.56 cm−1 and 3365.86 cm−1 which indicated the Fe-O-Si functional group and O-H stretching vibration. Results of UV-Vis DRS were analyzed using Origin Pro 2022 and revealed that the band energy gap for Fe3O4 and Fe3O4-SiO2 were 2.20 eV and 1.77 eV, respectively. The XRD results analysis with Match!3 software showed that for Fe3O4 had magnetite phases, while SiO2 had amorphous cristobalite phases. The 15% (w/v) Fe3O4 concentration in the form of powder and granules degraded batik liquid waste by 79.6% and 84.48%, respectively.
Enhanced Effectiveness on Phenol Removal by MgCr-LDH/Microcrystalline Cellulose Composite and Regeneration Study with Green Desorption Reagent Nova Yuliasari; Alfan Wijaya; Risfidian Mohadi; Aldes Lesbani
Science and Technology Indonesia Vol. 8 No. 1 (2023): 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.2023.8.1.151-159

Abstract

Modified MgCr-LDH with microcrystalline cellulose (MgCr/MCC) was successfully prepared by the coprecipitation method and characterized using XRD, FT-IR, and BET analyses. MgCr/MCC showed an increase in surface area from 21.51 to 26.056 m2/g. The material was tested as an adsorbent for the removal of phenol. MgCr/MCC showed an increase in adsorption capacity from the initial material of 24.631 to 58.480 mg/g. The optimum pH was at pH 9 and the adsorption process’s equilibrium time is 70 minutes. The correlation coefficients on the kinetics and isotherm parameters show that phenol removal follows the pseudo second order (PSO) and Langmuir models with spontaneous and endothermic adsorption processes. The regeneration ability of MgCr/MCC material using the water-assisted ultrasonic system as a green desorption reagent was 3 cycles with a percent regeneration efficiency of 39.45%.

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