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Science and Technology Indonesia
Number of Followers: 0  Open Access journalISSN (Print) 2580-4405 - ISSN (Online) 2580-4391 Published by Sriwijaya University  [4 journals]
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- Emerging Strategies for Mitigating Acid Mine Drainage Formation and
Environmental Impacts: A Comprehensive Review of Recent Advances
Authors: Yudha Gusti Wibowo, Muhammad Fauzul Imron, Setyo Budi Kurniawan, Bimastyaji Surya Ramadan, Tarmizi Taher, Alvian Hayu Sudibya, Hutwan Syarifuddin, Khairurrijal Khairurrijal, Jarwinda
Pages: 516 - 541
Abstract: Acid mine drainage (AMD) is a significant threat to the environment due to its high acidity and metal ion content. To effectively eliminate pollutants from AMD, various approaches are necessary. This review aims to provide a comprehensive understanding of recent advances in AMD mitigation. While treatment technologies have developed to eliminate AMD, they often produce sludge as a by-product and require expensive maintenance. As a cost-effective alternative, the recovery of AMD resources can reduce toxicity and promote reuse of heavy metals and rare earth elements. This review also analyzes the challenges and prospects of AMD mitigation implementation, including current mitigation conditions and knowledge gaps. Researchers can benefit from this review by gaining insight into research progress in this area, identifying strengths and weaknesses of current AMD mitigation applications, and exploring future research directions.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.516-541
Issue No: Vol. 8, No. 4 (2023)
- In Silico Analysis of Phenolic Compounds from Ceriops decandra Griff.
Leaves and Molecular Interaction as Anti Diabetes
Authors: Yunita Eka Puspitasari, Mochamad Arega Alfikri, Romasni Sitanggang, Jeny Ernawati Tambunan, Hardoko Hardoko
Pages: 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.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.542-553
Issue No: Vol. 8, No. 4 (2023)
- Modification of Pt-Porous Composite Material (Pt-PCM) and Its Application
for Electroanalysis of Uric Acid and Electrosynthesis of Acetic Acid from
Ethanol
Authors: Riyanto, Nurhasanah, Mohamed Rozali Othman
Pages: 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.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.554-559
Issue No: Vol. 8, No. 4 (2023)
- Secondary Metabolite of Endophytic Fungi Daldinia eschscholtzii from The
Leaves of Syzygium polyanthum
Authors: Mia Tirta Sari, Hary Widjajanti, Ferlinahayati, Hermansyah, Rian Oktiansyah, Elfita
Pages: 560 - 569
Abstract: Salam (Syzygium polyanthum) is a plant that is often used by Indonesian people as traditional medicine. The leaves are consumed to treat various diseases. This study reports the endophytic fungi found from S. polyanthum leaves and its secondary metabolites. Endophytic fungi species were determined through morphological and molecular identification. Potato Dextrose Broth medium was used for the cultivation process and ethyl acetate was used as a solvent for the extraction process. Antioxidant tests was carried out by using the DPPH method. Chromatographic techniques were used for the isolation of secondary metabolite and spectroscopic analysis was carried out to identify their chemical structures. The results of morphological and molecular analysis showed that the sample was Daldinia eschscholtzii. The secondary metabolite obtained from this endophytic fungus was idetified as fonsecinone A with good antioxidant activity. The secondary metabolite have the potential to become a source antioxidants through further research.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.560-569
Issue No: Vol. 8, No. 4 (2023)
- Towards Sustainable City: A Covering Model for Recycling Facility
Location-allocation in Nilai, Malaysia
Authors: Zati Aqmar Zaharudin, Adibah Shuib, Rieske Hadianti, Zahari Md Rodzi
Pages: 570 - 578
Abstract: Sustainable waste management is essential for any nation. To limit the amount of waste transported to landfills, it is critical to handle waste properly, notably by segregating recyclables from discarded waste. Waste separation at the source is critical to ensure that generated waste is not completely directed to landfill. The practice of waste separation would initiate the recycling process, which is able to reduce the amount of waste sent to the landfill. Recycling is critical to the achievement of two Sustainable Development Goals (SDGs), 11 and 12, for which Malaysian government has set the goal for recycling rates to reach 40% by 2025 in 2022, the rate has reached 33.17%. In Malaysia, recyclables are either collected on-site or sent to a designated facility. The separation at source activity is essential for developing recycling practices. Despite being the largest waste generator, public engagement, particularly at the household level, has remained low, most likely due to recycling facility availability and accessibility issues. Thus, improving public access to the facility would lead to increased recycling rates. In this study, a mixed integer linear programming model is proposed to locate recycling facilities in optimal locations that cover the most amount of waste generated by households. The capacity level is induced to ensure that the dropped-off recyclables are proportionate at the designated facility locations. Several experiments were conducted for validity purposes, and the proposed model was applied in a Malaysian urban area, namely Nilai. As a result, the proposed model was able to locate the optimal locations with the requisite capacity level while ensuring coverage for most Nilai households.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.570-578
Issue No: Vol. 8, No. 4 (2023)
- Green Synthesis of KO Nanoparticles by Cold Plasma and Study of Their
Properties for Antibacterial Applications
Authors: Mohammed Jawad Kadhim, Rana Ismael Khaleel, Karar Mahdi Talib, Raghad S. Mohammed
Pages: 579 - 584
Abstract: This study used the cold plasma technique to synthesize potassium oxide nanoparticles (KO NPs) from potassium chloride (KCl) with roselle extract leaves and examine their physical and biological characterization. The physical properties of KO nanoparticles were examined by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), X-Ray Dispersive Spectroscopy (EDS), and UV–Vis Spectroscopy. Analyses of XRD show the KO NPs with an average crystallite size of 108 nm. The EDX analysis shows that high-purity KO NPs have formed. SEM image shows the shapes of some KO NPs’ spherical with varying sizes ranging from 44.66 nm to 134 nm. According to UV–Vis spectra of KO NPs, the absorption edge of these nanoparticles exhibited a blueshift with an energy gap range (Eg) from 2.8 to 3.4 eV. The biological efficacy of KO NPs was also examined by testing their antibacterial and antifungal activity. To evaluate the toxicity of the KO NPs were tested in vitro and activated as antibacterial. Against some of the test organisms, the KO NPs demonstrated good antibacterial activity.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.579-584
Issue No: Vol. 8, No. 4 (2023)
- One-pot Hydrothermal Synthesis and Characterization of Zirconium Oxide
Nanoparticles
Authors: Suresh Sagadevan, Jayasingh Anita Lett, Is Fatimah
Pages: 585 - 593
Abstract: Zirconia (also known as zirconium dioxide, ZrO2) is a white crystalline naturally occurring mineral that offers excellent optical, dielectric, and mechanical properties. Considering these properties and referring to previous studies on the optimization of ZrO2 NPs synthesis, in the present study, we studied the crystalline, optical, and fluorescence properties of ZrO2 nanoparticles (NPs) formed by the hydrothermal synthesis route. The physicochemical features of the nanoparticles were examined in the photocatalytic oxidation of rhodamine B. From the powder XRD analysis, the ZrO2 NPs were found to be highly crystalline, while the fluorescence (FL) spectra indicated an emission band at 473 nm, which could be linked to a blue shift. Also, the FTIR and Raman spectroscopies confirmed the functionality and bonding, and in addition, the XPS analysis provided the elemental peaks of Zr 3d and O 1s, where all these analyses evidenced the successful formation of ZrO2. Examination of the photocatalytic activity of ZrO2 NPs revealed the capability of the material for rhodamine B photocatalytic degradation effectively, with a degradation efficiency of 86% after 2 h of treatment. Moreover, the nanoparticles exhibited stability and reusability over five cycles. Overall, from the analysis, ZrO2 NPs can be easily formed via the hydrothermal route with tailored optical and fluorescence properties to find applications in the electronics industry for the manufacturing of light emitting devices.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.585-593
Issue No: Vol. 8, No. 4 (2023)
- Preparation and Characterization of Fe2O3 from Iron Sand of the Coastal
Sea of Cidaun Beach-South Cianjur (Indonesia) using the Co-precipitation
Method
Authors: Endah Puspita, Masno Ginting, Ramlan
Pages: 594 - 598
Abstract: The synthesis and characterization of Fe2O3 from Iron Sand of the coastal sea of Cidaun Beach - South Cianjur using the coprecipitation method has been carried out. The purpose of this research was to identify the crystal structure, magnetic mineral content, and magnetic properties of iron sands. The characterizations used in this research are X-Ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) and Vibrating Sample Magnetometer (VSM). Based on the XRD results, it shows that the iron sand sample produces multi-phases, namely hematite (''''-Fe2O3), maghemite (''''-Fe2O3) and ilmenite (FeTiO3). SEM-EDX results indicate that the iron sand samples have an average particle size of 12.396 ''''m. VSM results indicate that the iron sand sample is soft magnetic (ferrimagnetic) with saturation, remanence and coercivity values of 47 emu/g, 1.53 emu/g and 102.97 Oe, respectively.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.594-598
Issue No: Vol. 8, No. 4 (2023)
- Antioxidant Activity Test of the Ethyl Acetate Fraction of Beluntas Leaves
(Pluchea indica L.) in White Male Rats Wistar Strain Induced Carbon Tetra
Chloride
Authors: Fitrya, Vitri Agustiarini, Adelia Indriyan, Herlina, Dwi Hardestyariki, Eka Febri Zulissetiana
Pages: 599 - 606
Abstract: Beluntas leaves contain flavonoids which have antioxidant effects. The purpose of this research was to determine the flavonoid total content, the effect of ethyl acetate fraction of beluntas on Malondialdehyde (MDA) levels, catalase enzyme activity, macroscopic pathology, histopathology description of white male rats wistar strain induced by CCl4 and of determining the best dose antioxidant. In this study, the in vivo tests used TBARS methods which consisted of six groups that are normal control, positive control (vitamin C 10 mg/kgBW), negative control (Na-CMC 1%), and treatment groups were given ethyl acetate fraction of beluntas leaves at doses 25 mg/kgBW, 50 mg/kgBW and 100 mg/kgBW. The total flavonoid content of the ethyl acetate fraction of beluntas leaves was 153 mgQE/g. The average results of MDA levels normal, positive, negative, doses fraction groups of 25, 50, and 100 mg/kgBW, respectively, were 1.155; 0.471; 1.892; 1.218; 0.826 and 0.512 nmol/mL. The average results of catalase enzyme activity of normal, positive, negative, doses fraction groups 25, 50, and 100 mg/kgBW, respectively, were 22.131; 40.489; 3.103; 14.145; 32.176, and 39.814 U/mL. The macroscopic and histopathology results show an improvement after being given the ethyl acetate fraction of beluntas leaves at doses of 25, 50, and 100 mg/kgBW compared to the negative control. The results showed that the ethyl acetate fraction of beluntas leaves reduce MDA levels and increases catalase enzyme activity. Ethyl acetate fraction of beluntas leaves at 100 mg/kgBW had the most potent antioxidant activity compared to doses of 25 and 50 mg/kgBB which were shown by Duncan’s statistical analysis that there was no significant difference with positive control.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.599-606
Issue No: Vol. 8, No. 4 (2023)
- Formulation and Evaluation of Antibacterial and Anti-Inflammatory Capsules
Containing Phyllanthus emblica L. Fruit Nanoparticles
Authors: Masfria, Sumaiyah, Hafid Syahputra, Marwin Witarman
Pages: 607 - 615
Abstract: Phyllanthus emblica fruit has diuretic, antibacterial, hepatoprotective, antitumor, hypocholesterolemic, antioxidant, and antiulcerogenic activities making it possible as a traditional medicine in capsule form. Capsule preparations have the advantage of covering the unpleasant taste and smell of medicinal ingredients, easy to swallow, so they are practical to use. This study aimed to formulate Phyllanthus emblica fruit nanoparticles in capsules and to test the antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa and anti-inflammatory activity by observing denaturation inhibition in vitro. The method used to manufacture Phyllanthus emblica fruit simplicia nanoparticles was used using a High Energy Ball mill grinding machine. Capsule formulation was carried out with various doses of nanoparticles (100, 150, and 200 mg). Evaluation includes weight uniformity and disintegration time. Test of its antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa and its anti inflammatory activity in vitro. The study found that all formulas could be made into capsules that met the evaluation test requirements. The results of the evaluation of disintegration time ranged from 6.17-11.33 minutes. For the evaluation results of weight uniformity, it was found that weight deviations in columns A1 and A2 were in the range between 0.9% to 2.8% and 0.9 to 1.3%. The study reports on the antibacterial activity of Phyllanthus emblica fruit nanoparticle capsules (PFNP) against Streptococcus mutans and Pseudomonas aeruginosa. The results indicate that PFNP exhibits a dose-dependent antibacterial effect, with inhibition zone diameters of 10.83 mm, 11.6 mm, and 12.63 mm observed at 100 mg, 150 mg, and 200 mg, respectively, against Streptococcus mutans. Similarly, PFNP demonstrated a dose-dependent antibacterial effect against Pseudomonas aeruginosa, with inhibition zone diameters of 10.7 mm, 11.4 mm, and 12.1 mm observed at doses of 100 mg, 150 mg, and 200 mg, respectively. PFNP capsules showed inhibition results with a value of 5.63%, 6.13%, and 6.80%. It was concluded that Phyllanthus emblica fruit nanoparticles (Phyllanthus emblica L.) could be formulated in capsule dosage forms with doses of 100 mg, 150 mg, and 200 mg; has antibacterial activity against Streptococcus mutans and Pseudomonas aeruginosa, and has no anti-inflammatory activity.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.607-615
Issue No: Vol. 8, No. 4 (2023)
- Fabrication and Characterization Fe3O4/Humic Acid for the Efficient
Removal of Malachite Green
Authors: Nur Ahmad, Zaqiya Artha Zahara, Alfan Wijaya, Fitri Suryani Arsyad, Idha Royani, Aldes Lesbani
Pages: 616 - 625
Abstract: The dye pollutants that contaminate water and food resulting from commercial manufacture and illicit addiction are a worldwide threat that harms the ecosystem, the food supply, and the health of humans. Magnetite/Fe3O4 humic acid (MHA) with various ratios was synthesized using a two-step process involving coprecipitation and hydrothermal treatment in order to effectively overcome these obstacles. Analyses of SEM, XRD, FTIR, and VSM were used to describe the morphology and physicochemical aspects of MHA. The adsorption kinetics studies indicated that the adsorption mechanism of malachite green adhered to the pseudo-second-model and that the adsorption was adequately described by the Langmuir isotherm. The thermodynamic studies demonstrated spontaneous, endothermic, disorderly adsorption. MHA2 had maximal malachite green adsorption capacities of 83.333 mg/g. Malachite green and MHA may interact via interaction, electrostatic attraction, van der Waals forces, H-bonding, pore filling, pore locking, and/or mechanical adhesion; however, physisorption dominates the adsorption process. Malachite green's adsorption characteristics change significantly after up to four cycles. It has been demonstrated that MHA has a high capacity for dye adsorption and a broad range of potential applications.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.616-625
Issue No: Vol. 8, No. 4 (2023)
- Monitoring the Muara Laboh Geothermal Field in Indonesia using the ISBAS
Method with Sentinel-1 SAR Images
Authors: Mokhamad Yusup Nur Khakim, Takeshi Tsuji, Erni, Akhmad Aminudin Bama, Frinsyah Virgo, Muhammad Irfan, Azhar Kholiq Affandi, Toshifumi Matsuoka
Pages: 626 - 631
Abstract: The Muara Laboh geothermal field lies in a South Solok basin zone, West Sumatra, Indonesia. Production and reinjection of geothermal fluids into the underground reservoir commonly induce crustal deformation. The study area is covered by 63.8% plantation, primary, and secondary forests, which limit the ability of conventional InSAR techniques. Therefore, an Intermittent Small BASeline Subset (ISBAS) analysis has been performed to estimate line-of sight (LOS) displacement time series due to geothermal production using the Sentinel-1 dataset between 8 March 2021 and 15 March 2022. The localized subsidence with ∼30 mm/yr rate over this tropical geothermal field has been revealed by using the ISBAS. The subsidence coincides with an area of the Muara Laboh geothermal reservoir. We suggest that geothermal production induced subsidence. In addition, the deformation in this geothermal field was controlled by faults and seasonally influenced by rainfall. Therefore, deformation variation was correlated with fluctuations in rainfall patterns. The geothermal reservoir system exhibited elastic expansion in response to seasonal recharge events during the rainy season.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.626-631
Issue No: Vol. 8, No. 4 (2023)
- The Electrochemical Conversion of CO2 into Methanol with KHCO3 Electrolyte
Using Membrane Electrode Assembly (MEA)
Authors: Dedi Rohendi, Nyimas Febrika Sya’baniah, Edy Herianto Majlan, Nirwan Syarif, Addy Rachmat, Dwi Hawa Yulianti, Icha Amelia, Dimas Ardiyanta, Isya Mahendra, Rr. Whiny Hardiyati Erliana
Pages: 632 - 639
Abstract: The electrochemical conversion process of CO2 into methanol using Membrane Electrode Assembly (MEA) has been done. The MEA consists of a Pt/C catalyst in the cathode and a Cu2O ZnO/C catalyst in the anode. The electrodes were made using the spraying method and then characterized using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) methods to determine the ECSA (Electrochemical Surface Area) and electrical conductivity values. Besides that, also X-Ray Diffraction (XRD) and Scanning Electrode Microscopy – Energy Dispersive X-Ray (SEM-EDX) analysis was to determine the crystal and morphological structure. The voltammogram from CV analysis indicated that the ECSA value on the Pt/C electrode was 7.2 m2/g and the Cu2O-ZnO/C electrodes as 0.69 m2/g. The electrode’s electrical conductivity value with Pt/C catalyst was 1.15 x 10−3 S/cm, and the electrode with Cu2O-ZnO/C catalyst was 0.80 x 10−3 S/cm. The results of the XRD analysis confirmed the presence of Cu2O and ZnO on the Cu2O-ZnO/C electrode and Pt on the Pt/C electrode. Meanwhile, the results of the SEM-EDX analysis showed that the Pt/C catalyst was spread more evenly with a larger percentage than Cu2O and ZnO. The result of the conversion of CO2 to methanol was measured using a methanol analyzer with variations in KHCO3 electrolyte concentration, variation of temperature operation, and variation of time operation. The best methanol concentrations after distillation process were 79.06 w/v %, with 1 M KHCO3, at room temperature and 2 hours operation.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.632-639
Issue No: Vol. 8, No. 4 (2023)
- Studying the Structure Properties of Copper Nanoparticles Prepared by
Chemical Reduction Method
Authors: Noora H. Al-Zobiadi, Ammar A. Habeeb, Awatif S. Jasim
Pages: 640 - 646
Abstract: The chemical reduction method (CRM) can produce high purity nanoparticles, it is a down-top chemical method based on the principle of salt reduction, this method is used in this work to synthesis copper nanoparticals (CuPNs) by use different concentrations of copper nitrate. The properties of the prepared nanoparticles were studied by fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy were used to measure the absorbance spectra of the produced particles. According to the scanning electron microscope (SEM), the particles’ diameters range from (61.64 to 49.25) nm. According to X-ray diffraction, the particles exhibit a face monoclinic crystal structure (FCC). According to the transmission electron microscope findings, the particles are asymmetrically spherical in shape.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.640-646
Issue No: Vol. 8, No. 4 (2023)
- Formation of Hydroxyl-Amide Solid Dispersion Involving Azithromycin and
Chitosan-Alginate Biopolymer to Increase the Dissolution Rate of
Azithromycin
Authors: Mardiyanto, Budi Untari, Ady Mara, Diko Fahri Ferdiansyah
Pages: 647 - 653
Abstract: Research to increase the solubility of active pharmaceutical ingredients is usually conducted by reducing the particle size. This research is one side that used the solid dispersion systems to increase solubility, especially on macrolide antibiotics for which there is still little information. The co-grinding technique on azithromycin-chitosan-alginate was chosen to produce a solid dispersion system. The parameters observed were changes in crystal structure, FTIR spectral patterns, morphological changes, and dissolution profile changes. The results of this research showed a change in the pattern of X-diffraction of azithromycin, physical interaction between azithromycin and the polymer, changes in the image of surface of solid dispersions, the solubility of solid dispersions in simulated-intestinal-fluid (SIF) solutions, and an increase in the dissolution rate of azithromycin indicating that the co-grinding technique to produce solid dispersions can increase the solubility of azithromycin.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.647-653
Issue No: Vol. 8, No. 4 (2023)
- Improve Fuzzy Inventory Model of Fractal Interpolation with Vertical
Scaling Factor
Authors: Eka Susanti, Fitri Maya Puspita, Siti Suzlin Supadi, Evi Yuliza, Ahmad Farhan Ramadhan
Pages: 654 - 659
Abstract: The inventory model is used to determine the optimal inventory of a product. In certain cases, parameters in the inventory model are uncertain. Fractal interpolation techniques can be used to overcome parameter with uncertainty. Fractal interpolation results are affected by the fractal interpolation function and the vertical scaling factor. The vertical scaling factor is positive and less than 1. In this study, fractal interpolation techniques are introduced with variations in vertical scaling factor to overcome the uncertainty of demand data in inventory models. Furthermore, the interpolation results are used in fuzzy inventory models and expressed by Trapezoidal Fuzzy Number. This paper considers an inventory model with varying demand to optimize rice inventory. Based on the data obtained, the accuracy level will increase for the vertical scaling factor values close to 1. Optimal rice inventory of each successive fuzzy parameter is 1447963, 1013914, 504950, 215312. If the cost parameter is increased, then the amount of inventory is decreases.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.654-659
Issue No: Vol. 8, No. 4 (2023)
- Colorimetric Sensing of Ascorbic Acid Using Cu-Phen MOFs and Subsequent
Digital Image Analysis with Smartphone
Authors: M. Lutfi Firdaus, Rizki M. Okumura, Euis Nursaadah, Dewi Handayani, Afrizal Mayub, Lena Rahmidar, Muhamad Diki Permana, Annisa Luthfiah, Santhy Wyantuti, Diana R. Eddy, Yeni Wahyuni Hartati
Pages: 660 - 665
Abstract: Vitamin C, also known as ascorbic acid, is a crucial nutrient involved in a number of enzymatic processes for tissue healing. Additionally serving as an antioxidant, ascorbic acid is crucial for keeping the immune system strong. It is essential to create a quantitative analytical approach to ascertain ascorbic acid concentration in many samples since its consumption from the daily food should be in the proper quantity. Here, we present a colorimetric probe made of synthetic metal-organic frameworks (MOFs) that changes its color only when samples containing ascorbic acid are present. In this study, phenanthroline served as an organic ligand or linker while copper served as the core metal that formed bonds with it. Cu-Phen MOF color fluctuations at 410 nm (from 408 nm to 412 nm) are linearly related to variations in light absorption. Moreover, as a substitute for spectrophotometry UV-visible, we have created a digital image-based colorimetry. The Cu-Phen MOFs’ color change has the maximum slope and linearity when the blue color intensity is used. The detection limit with high precision of 4.2% under ideal circumstances was 0.1 ppm. The established approach allowed for the exact and accurate assessment of ascorbic acid in genuine samples of star fruit (Averrhoa carambola L.).
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.660-665
Issue No: Vol. 8, No. 4 (2023)
- Optimal Conditions for Alkaline Delignification Process in Cellulose
Isolation from Sengon Wood Sawdust
Authors: Intan Martha Cahyani, Adhyatmika, Endang Lukitaningsih, Teuku Nanda Saifullah Sulaiman
Pages: 666 - 674
Abstract: Sengon wood sawdust (SWS) is a solid waste of the wood industry with the potential as a source of cellulose and can increase its economic value. However, cellulose in plants is tightly bound to lignin which is called lignocellulose therefore needs to be delignified before utilization. In this study, we determined the optimum conditions for delignification from sengon wood sawdust cellulose (SWSC). Optimization variables were determined with the parameter of obtained hemicellulose, cellulose, and lignin content. The optimization of SWSC delignification was then carried out using the factorial design by analyzing the effect of sodium hydroxide (NaOH) concentration (2% - 10%) and ratio (SWS : NaOH solution) (1:10 – 1:80) on hemicellulose, cellulose, and lignin content. Optimal conditions were obtained at 2% NaOH (1:19.20) with concentrations of 8.01% hemicellulose, 52.49% cellulose, and 22.2% lignin. One sample T-test analysis of predictive and research values of hemicellulose, cellulose, and lignin showed insignificant results (P>0.05) which means that the optimization equation proved valid to determine the optimum conditions for cellulose delignification of sengon wood sawdust. FT-IR analysis, SEM imaging, and particle size distribution (PSA profile) showed that the cellulose produced under these conditions has similar characteristics to the standard of Avicel® PH 102.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.666-674
Issue No: Vol. 8, No. 4 (2023)
- An Assessment of Pb and Cu in Waters, Sediments, and Mud Crabs (Scylla
serrata) from Mangrove Ecosystem Near Tanjung Api-Api Port Area, South
Sumatra, Indonesia
Authors: Rozirwan, Aning Puji Saputri, Redho Yoga Nugroho, Nadila Nur Khotimah, Wike Ayu Eka Putri, Fauziyah, Anna Ida Sunaryo Purwiyanto
Pages: 675 - 683
Abstract: Heavy metal pollution from anthropogenic activities can harm aquatic ecosystems. This study aims to determine the concentration of heavy metals (Pb and Cu) in waters, sediments, and mud crabs (Scylla serrata), and to analyze the relationship between environmental parameters and S. serrata consumed by humans. Samples were taken in the mangrove ecosystem around the Tanjung Api-Api port area in South Sumatra, Indonesia. Pb and Cu analysis used the Atomic Absorption Spectrophotometer (AAS). Pb and Cu linkages in waters, sediments, and S. serrata analyzed by SigmaPlot V12.5 and Principal Component Analysis (PCA) analyzed by XLSTAT 2022. The limit consumption of S. serrata was calculated using MWI (Maximum Weekly Intake) and MIT (Maximum Intake Tolerance). Based on the results, the heavy metal Pb in water was 0.1055 – 0.1322 mg.L-1, and Cu was not detected. Furthermore, Pb in sediments ranged from 7.0104 - 11.8186 mg.kg-1, Cu 3.7127 - 4.5347 mg.kg-1, and Pb in S. serrata ranged from 0.0001 - 0.0021 mg.kg-1, and Cu ranged from 0.03 – 0.0791 mg.kg-1. The concentration of heavy metals in water, sediment, and S. serrata had not exceeded the specified quality standard, except for Pb in water. The principal component analysis obtained F1 (44.35%), F2 (27.53%) and F3 (17.83%) groups. Based on MWI and MIT value, it showed high quality which concluded S. serrata was still safe for human consumption.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.675-683
Issue No: Vol. 8, No. 4 (2023)
- Solving the Shortest Total Path Length Spanning Tree Problem Using the
Modified Sollin and Modified Dijkstra Algorithms
Authors: Wamiliana, Reni Permata Sari, Astri Reformasari, Jani Suparman, Akmal Junaidi
Pages: 684 - 690
Abstract: In a weighted connected graph, the shortest total path length spanning tree problem is a problem when we need to discover the spanning tree with the lowest total cost of all pairwise distances between its vertices. This problem is also known as the minimum routing cost spanning tree (MRCST). In this study, we will discuss the Modified Sollin and Modified Dijkstra Algorithms to solve that problem which implemented on 300 problems are complete graphs of orders 10 to 100 in increments of 10, where every order consists of 30 problems. The results show that the performance of the Modified Dijkstra and the Modified Sollin Algorithms are slightly similar. On orders 10, 20, 30, 60, and 80, the Modified Dijkstra Algorithm performs better than the Modified Sollin, however on orders 40, 50, 70, 90, and 100, the Modified Sollin performs better.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.684-690
Issue No: Vol. 8, No. 4 (2023)
- Extreme Drought Assessment in Sumatra-Indonesia Using SPI and EDI
Authors: Suhadi, Iskhaq Iskandar, Supari, Muhammad Irfan, Hamdi Akhsan
Pages: 691 - 700
Abstract: Even though Sumatra is very vulnerable to the effects of drought, research identifying drought on this island is very limited, especially extreme drought. This research was conducted to identify extreme drought in Sumatra using the Standardized Precipitation Index (SPI) and the Effective Drought Index (EDI). This study uses precipitation data from the Indonesian Meteorology, Climatology and Geophysics Agency (BMKG) and Global Precipitation Climatology Center (GPCC) reanalysis data. The composite indices were conducted to discover some phenomena that cause the drought based on El Niño and positive Indian Ocean Dipole (IOD) events. The results showed that the El Niño and positive IOD phenomena were more likely to influence extreme droughts. However, the droughts in 2014 and 2008 tended to be influenced by the negative Sea Surface Temperature anomaly (SSTA). The spatial analysis results show that the areas that experience extreme drought more often are the west coast of Sumatra (except Aceh province), especially based on SPI12 and EDI. The composite indices results show that the drought that occurred in Aceh province was more influenced by the El Niño phenomenon in the December-January-February (DJF) period and the positive IOD in the June-July-August (JJA) – September-October-November (SON) period. In addition, Aceh province is an area that is not affected by El Niño-positive IOD, especially during the SON-DJF period. These results can be used to mitigate drought, especially when El Niño-positive IOD phenomena cause it.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.691-700
Issue No: Vol. 8, No. 4 (2023)
- Synthesis of Zn/Al-ZnO Composite Using Zn/Al-Layered Double Hydroxide for
Oxidative Desulfurization of 4-Methyldibenzothiophene
Authors: Risfidian Mohadi, Nur Ahmad, Sahrul Wibiyan, Zaqiya Artha Zahara, Erni Salasia Fitri, Mardiyanto, Idha Royani, Aldes Lesbani
Pages: 701 - 709
Abstract: Zn/Al-ZnO composites made from Zn/Al-Layered Double Hydroxide base material and ZnO as a precursor were successfully made in this study. Characterization analysis using SEM-EDS, XRD, and FTIR. The SEM analysis results show the Zn/Al-LDH has a smooth surface, overlapping, and is prone to aggregation, resulting in non-uniform particle size. However, it forms a uniform grain shape. Zn/Al-ZnO have rough surfaces with uniform particle shape and size, and the presence of pores on the particle surface. EDS analysis shows the Zn element which is more abundant in Zn/Al-ZnO. XRD analysis of Zn/Al-LDH showed the hydrotalcite. XRD analysis on ZnO showed the hexagonal wurtzite crystal structure. Zn/Al-ZnO composites at an angle of 2θ show the same peak of the base material and the precursor. FTIR analysis of the composite revealed the presence of O-H groups at wave numbers 3445 cm−1, 1633 cm−1, and 1504 cm−1, indicating the presence of nitrate. Additionally, vibrations at wave numbers 1382 cm−1 corresponded to antisymmetric (v3) stretching of nitrate, while wave numbers 418 cm−1 and 606 cm−1 indicated metal-oxygen stretching vibrations. Of all the factors used in the desulfurization of 4-methyldibenzothiophene, Zn/Al-ZnO composites had the highest %conversion rate of both the base material and the precursor. The %conversion values of Zn/Al-ZnO at the time of contact were 99.40%, catalyst dosage 99.38%, solvent 99.10%, and temperature 99.56%, respectively. The catalyst is heterogeneous and reusable for the desulfurization of 4-methyldibenzothiophene.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.701-709
Issue No: Vol. 8, No. 4 (2023)
- Spectroscopic Diagnostics of Spectral Lines Emission from Cu Plasma within
the Visible Spectrum Range
Authors: Hayim Ch. Magid, Bushra Khamas Abbas, Dunia F. T. AL-Ani
Pages: 710 - 715
Abstract: The creation and characterization of laser-induced plasma (LIP), a significant phenomenon in several applications, are influenced by the sample’s physical qualities as well as the laser’s parameters. In this research, we created Cu plasma in the atmosphere using an Nd: YAG laser operating at a wavelength of 532 nm with a laser irradiance energy range (400-800) mJ. The effect of the laser’s irradiance energy on the plasma characteristics was investigated using optical emission spectroscopy (OES). Using the two ratio and Stark broadening methods, we successfully measured the two most important plasma properties (electron temperature and electron density). The electron’s plasma temperature value ranged from 2.3 to 3 eV. The value of electron plasma density is in the range from 6.75×1017 to 15×1017 cm−3. Also, we found that other plasma parameters like plasma frequency (fp), particles in the Debye sphere (ND), and Debye length ('D) are affected by laser energy. Where plasma frequency ranged from 7.378 to 10.998×1012 Hz, the Debye sphere ranged from 7.294 to 7.022×103, and the range of Debye length from 1.372 to 1.038×10−5 cm.
PubDate: 2023-10-01
DOI: 10.26554/sti.2023.8.4.710-715
Issue No: Vol. 8, No. 4 (2023)
