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Science and Technology Indonesia

JSTI
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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

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Articles 551 Documents

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Biogenic Amines Detection by Chromatography and Sensor Methods: A Comparative Review Muhammad Abdurrahman Munir; Khairiah Haji Badri; Lee Yook Heng
Science and Technology Indonesia Vol. 5 No. 4 (2020): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Biogenic amines (BA) are chemistry compounds shaped by amino acids decarboxylation and exist in protein food and beverages. They are labelled toxic if consumed and some countries prohibit to consume them in high level especially histamine. Two major methods have been used and developed well such as chromatography methods and sensors methods. The common method applied for chromatography namely liquid chromatography (LC) and gas chromatography (GC) while for sensor methods such as optical, chemical and bio sensor. These methods have advantages and disadvantages. For chromatography methods, derivatization methods are required in order to improve their sensitivity and selectivity, nevertheless these methods are very expensive and time-consuming. During derivatization step, it needs more time and bear the risk of an only partial detection due to an incomplete derivatization. Furthermore, sensor methods exist to solve these issues, while they do not require derivatization step, generate a direct signal that can be interpreted by anyone, very fast and simple, yet they have disadvantages in several aspects such as sensitivity, accuracy and selectivity compared to chromatography methods. This review is based on studies about biogenic amines detection from the last decades until now and related to food and beverage samples. Although biogenic amines commonly found in protein-food for decades, new approaches and technical possibilities still required in order to increase the sensitivity, selectivity and accuracy of analytical methods to tackle the complexity by their matrices. The rationale of this study is also to provide data about the comparison of the analytical techniques between conventional and sensor methods. Furthermore, the various approaches of biogenic amines determination and the most applied analytical methods have been reviewed.

Facile Detection of Oil Adulteration using UV-Visible Spectroscopy Coupled with Chemometrics Analysis Nina Gusti; Dinda Oktarina; Rina Elvia; Euis Nursa’adah; Rendy W Wardhana; Agus Sudaryono; M. Lutfi Firdaus
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Engine and machine oils, better known as lubricant, is a fast-moving part within the motorcycle and automobile industries. Due to its high demand, these oils are often counterfeited by irresponsible people to get more profit. The thing most often done to adulterate oil is by mixing it with other low-quality or used oil. Here, we propose a simple analytical method to identify oil adulteration by using UV-Visible spectroscopy. A number of 425 genuine and adulterated oils were used as samples. After appropriate dilution using n-hexane, the samples were analyzed by UV-Visible spectrophotometer followed by Principle Component Analysis (PCA) and Principle Component Regression (PCR) as part of the chemometrics analysis. The results show that prediction samples were accurately classified into their corresponding groups with PCA scores of 49% and 27% for principal component 1 and 2, respectively. PLS model achieved a good prediction to detect lubricant oil adulteration, with R-Square of predicted and reference samples were 0.9257 and 0.9204, respectively. The proposed method shows a promising alternative to the conventional chemical method using a more sophisticated instruments such as GC-MS and HPLC for oil or other organic compound identification.

Fish Analysis Containing Biogenic Amines Using Gas Chromatography Equipped With Flame Ionization And Mass Spectrometer Detectors Muhammad Abdurrahman Munir; Ahlam Inayatullah; Hamid Alkhair Badrul
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Biogenic amines generally can be found in fish due to amines in fish undergoing a degradation process. According to the United States Food and Drug Administration (FDA), biogenic amines in fish and fish products can cause harm to consumers if consumed more than 50 µg/mL. Thus, it is important to analyze them. Five biogenic amines such as heptylamine, histamine, tyramine, cadaverine and spermidine were extracted using soaking method with methanol 50% (v/v), afterward they were detected in fish and fish products using gas chromatography – flame ionisation detector (GC-FID) and the biogenic amines structures were confirmed using mass spectrometry (MS). The detection limits (DLs) were range at 1.20 – 2.90 µg/mL. Histamine was detected in fish and fish products such as sardine (Sardinella gibosa) and mackerel (Scomberomorus guttatus) at concentration of 5.96 and 2.69 µg/mL, respectively, whereas cadaverine was found in sardine (Sardinella gibosa) at concentration of 4.96 µg/mL. Histamine concentrations in this study were detected below 50 µg/mL which is below the permissible threshold associated with scombroid poisoing.

Preparation and Characterization of Petai Pods Extract (Parkia speciosa Hassk.) Loaded Ethosomes Fitrya Fitrya; Najma Annuria Fithri; Annisa Amriani; Annisa Haryati; Dina Permata Wijaya
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Preparation of petai pods extract (Parkia speciosa) into ethosome aim to increased penetration through the skin. The method of cold is used in preparing petai pods extract encapsulation by ethosome with variation in concentration of soya lecithin, propylene glycol, and ethanol. The proportion of optimum formula ethosome consisted were 0,2 g soya lecithin, 1 ml propylene glycol, and 4 ml ethanol that response values obtained pH of 4,74, viscosity of 0,950 cP, %EE of 74,326%, and stability of 7,288%. The resulted of optimum formula obtained were PDI of 0,23, zeta potential of -7,5 mV, and particle size of 818,7 nm. Ethosome showed spheric particle using Transmissin Electron Microscopy. The diffusion analysis showed highest on ethosome of petai pods extract (9,525%) than petai pods extract (5,466%). The interaction study used FTIR show no chemical interaction extract pods and ethosome components

End-to-End Delay QoS Attribute-Based Bundling Strategy of Wireless Improved Reverse Charging Network Pricing Model Fitri Maya Puspita; Ayu Wulandari; Evi Yuliza; Robinson Sitepu; Yunita Yunita
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

In this article, a multi-link internet reverse charging (IRC) scheme model in a multi-service network with the addition of a bundling strategy is proposed. Reverse charging schemes in multi-link and multi-service networks are rarely discussed in previous studies. This financing scheme is designed with the aim of maximizing service provider profits by minimizing internet usage costs. The basic cost and satisfaction level of the service provided by the ISP is focused on this effort. The model formed in this study is a Mixed Integer Non-Linear Programming (MINLP) model that is completed using software LINGO 13.0. This problem comprises two cases, when α case as a parameter and β as a parameter and or variable with sub–cases increases in usage based financing schemes. Thus, the results obtained can be a consideration for ISPs in determining the price of services that can support an ISP. The updated IRC model provides a more optimal solution than the original IRC model.

Column Generation Model in Capacitated Multi-Periods Cutting Stock Problem with Pattern Set-Up Cost Putra Bahtera Jaya Bangun; Sisca Octarina; Laila Hanum; Ranti Sawitri; Endro Sastro Cahyono
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Cutting Stock Problem (CSP) determines the cutting of stocks with standard length and width to meet the item’s demand. The optimal cutting pattern will minimize the usage of stocks and trim loss. This research implemented the pattern generation algorithm to form the Gilmore-Gomory and Column Generation model in two-dimensional CSP. The CSP in this research had three periods of cutting with different capacities in each period. The Column Generation model added the pattern set-up cost as the constraint. The Gilmore-Gomory model ensured that the first stage’s strips were used in the second stage and met the item’s demand. Based on the Column Generation model’s solution, the 1st period used the 2nd, 4th, and 5th patterns, the 2nd period used 4th and 5th patterns, and the 3rd period did not use any patterns. The first and second periods fulfilled all of the demands.

CuO Nanoparticles : Biosynthesis, Characterization and In Vitro Study Ahmad Fatoni; Reza Agung Sriwijaya; Umy Habiba; Nurlisa Hidayati
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

The biosynthesis of CuO nanoparticles was studied. The aims of this research were biosynthesis CuO nanoparticles from Cu2+ion solution and leaves aquoeus extract of sweet star fruit and its in vitro study as antibacterial agent of Escherichia coli. CuO nanoparticles was characterized using FTIR spectroscopy and X-Ray diffractometer. CuO nanoparticles was synthesized by reaction between Cu2+ion solution and leaves aquoeus extract of sweet star fruit. Paper disk method was used as the application of the suspension of CuO nanoparticles. The result showed that Cu-O groups detected at wave number of 503, 619, 767 and 821 cm-1. Diffractogram of CuO nanoparticles had sharp and narrow diffraction peaks. The crystallite size of CuO nanoparticles was 4.25 nm. The average inhibition zone of CuO nanoparticles at concentration 10.000, 7.500, 5.000 and 2.500 ppm was 17.43 ± 1.81 ; 15.73 ± 0.40 ; 14.50 ± 2.96 and 9.67 ± 0.28 mm respectively.

Seagrass Cholorophyll-a, Biomass and Carbon Algorithms Based on the Field and Sentinel-2A Satellite Data at Karimunjawa Island, Indonesia Agus Hartoko; Yoan Teresia Sembiring; Nurul Latifah
Science and Technology Indonesia Vol. 6 No. 3 (2021): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Chlorophyll-a in seagrass biomass is functioned for the photosynthetic process and store the organic carbon in their biomass of the leaf, rhizome, and root. Ecologically has functioned as blue carbon in reducing global warming adaptation and mitigation strategy. The study aimed to explore seagrass species, chlorophyll-a content, biomass and carbon stock at Karimunjawa Island. Develop algorithms of the Sentinel-2A satellite data based on field seagrass chlorophyll-a, biomass and carbon and at Pokemon and Bobby beach Karimunjawa Island. Four species of seagrass found at Bobby and Pokemon beach are Holodule pinifolia with a density of 160.44 ind.m−2 , Enhalus acoroides with 26.22 ind.m−2, Halophila ovalis with 6.67 ind.m−2 and Thalassia hemprichii with 4.44 ind.m−2.The lowest seagrass chlorophyll-a is 5.854 mg.ml−1 found in H. pinifolia and the highest is 20.819 mg.ml−1found in E. acoroides at Pokemon beach. The range of seagrass chlorophyll-a at Bobby beach was 3.485 - 14.133 mg.ml−1 in T. hemprichii. The smallest individual biomass dry weight was found in T.hempirichii with 1.32 g.dry.weight per individu, and the biggest in E.acoroides with 6.98 g.dry.weight per individu. The highest seagrass biomass at Pokemon beach was in E. acoroides with 236.93 g.m−2 which has a wide leaf morphology and the lowest in H. pinifolia with 75.91 g.m−2 with the smallest leaf morphology. The range of seagrass biomass at Bobby beach is 97.62 - 264.48 g.m−2 which is dominated by T.hempirichii. The range of seagrass carbon was 109.63 - 136.82 gC.m−2at Pokemon beach, and in the range of 95.00 - 114.01 gC.m−2 at Bobby beach. Algorithm of seagrass chlorophyll-a = -36.308 (B3/B4)2 – 140.41(B3/B4) + 83.912 ; biomass = -7028.3 (B3/B4)2 + 14948 (B3/B4) – 7764.4; carbon = -17.529(B2/B3)2 + 143.82(B2/B3) – 5.3362 for Pokemon beach. Algorithm of chlorophyll-a = 455.02 (B2/B4)2 + 823.72 (B2/B4) + 375.48; biomass = -14699 (B3/B2)2 + 28395(B3/B2) – 13537; and carbon = - 0.001(B3/B4)2+ 0.209(B3/B4) - 10.203 for Bobby beach. The use of Band-2 (0.490 ????m), Band-3 (0.560 ????m) and Band-4 (0.665 ????m) Sentinel-2A satellite data in the development of seagras chlorophyll-a, biomass and carbon algorithm was found to be significant.

Structure and Dynamics of Curcumin Encapsulated Lecithin Micelles: A Molecular Dynamics Simulation Study Lukman Hakim; Diah Mardiana; Urnik Rokhiyah; Maria Lucia Ardhani Dwi Lestari; Zubaidah Ningsih
Science and Technology Indonesia Vol. 6 No. 3 (2021): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Curcumin is a natural product with potential pharmaceutical applications that can be augmented by drug delivery technology such as nano emulsion. Our study focuses on microscopic structural and dynamics response of curcumin encapsulation in micellar system with lecithin as a natural surfactant under variations of composition and temperature using molecular dynamics (MD) simulations. The results highlight the self-assembly of lecithin micelle, with curcumin encapsulated inside, from initial random configurations in the absence of external field. The variation of composition shows that lecithin can aggregate into spherical and rod-like micelle with the second critical micelle concentration lies between 0.17-0.22 mol dm−3. The radial local density centering at the micelle center of mass shows that the effective radius of micelle is indeed defined by the hydrophilic groups of lecithin molecule and theencapsulated curcumin molecules are positioned closer to these hydrophilic groups than the innermost part of the micelle. The spherical micelle is shown to be thermally stable within the temperature range of 277-310 K without a perceivable change in the spherical eccentricity. The dynamics of micelle are enhanced by the temperature, but it is shown to be insensitive to the variation of lecithin-curcumin composition within the studied range. Simulation results are in agreement with the pattern obtained from experimental results based on particle size, polydispersity index, and encapsulation efficiency.

Determining the Credit Score and Credit Rating of Firms using the Combination of KMV-Merton Model and Financial Ratios Norliza Muhamad Yusof; Iman Qamalia Alias; Ainee Jahirah Md Kassim; Farah Liyana Natasha Mohd Zaidi
Science and Technology Indonesia Vol. 6 No. 3 (2021): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Credit risk management has become a must in this era due to the increase in the number of businesses defaulting. Building upon the legacy of Kealhofer, McQuown, and Vasicek (KMV), a mathematical model is introduced based on Merton model called KMV-Merton model to predict the credit risk of firms. The KMV-Merton model is commonly used in previous default studies but is said to be lacking in necessary detail. Hence, this study aims to combine the KMV-Merton model with the financial ratios to determine the firms’ credit scores and ratings. Based on the sample data of four firms, the KMV-Merton model is used to estimate the default probabilities. The data is also used to estimate the firms’ liquidity, solvency, indebtedness, return on asset (ROA), and interest coverage. According to the weightages established in this analysis, scores were assigned based on those estimates to calculate the total credit score. The firms were then given a rating based on their respective credit score. The credit ratings are compared to the real credit ratings rated by Malaysian Rating Corporation Berhad (MARC). According to the comparison, three of the four companies have credit scores that are comparable to MARC’s. Two A-rated firms and one D-rated firm have the same ratings. The other receives a C instead of a B. This shows that the credit scoring technique used can grade the low and the high credit risk firms, but not strictly for a firm with a medium level of credit risk. Although research on credit scoring have been done previously, the combination of KMV-Merton model and financial ratios in one credit scoring model based on the calculated weightages gives new branch to the current studies. In practice, this study aids risk managers, bankers, and investors in making wise decisions through a smooth and persuasive process of monitoring firms’ credit risk.

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