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Science and Technology Indonesia

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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 581 Documents

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Study of The Electrical, Optical and Morphological Properties in Submicron and Microstructured ZnO Thin Films Obtained by Spin Coating and Chemical Bath Deposition C. López-Esmerio; C. Ruiz-Rojas; J. Angulo-Rocha; E. Lizárraga-Medina; Francisco Ramos-Brito; E. Camarillo-García; R. Martinez-Martinez; M. Aguilar-Frutis; M. García-Hipólito
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

In the present work the synthesis of ZnO semiconductor thin films was performed successively using spin coating and chemical bath deposition techniques. The deposition was made by varying the concentration of zinc acetate and hexamethylenetetramine (HMTA: ZnAc) in the precursor solution. This process led to two preferred growth directions (002) and (101), both with very similar texture coefficients, too; a noticeable change in morphology of structured surface, variation in unit cell parameters and crystalline grain size. All the films turned out homogeneously submicro and microstructured and with a wurtzite-type hexagonal crystalline structure. Using pre-loaded Mathematica 11.3 software functions and an algorithm developed in it, the micrographies were analyzed to calculate the percentage of substrate-covered area which was always greater than 80%. Likewise, it also found that resistivity decreases at a higher percentage of covered area and that the variation in the shape of the photo luminescent emission spectrum can be considered as a qualitative indication of the concentration of charge carriers.

Synthesis of Cellulose–Polylactic Acid Microcapsule as a Delivery Agent of Rifampicin Suripto Dwi Yuwono; Ridho Nahrowi; Andi Setiawan; Ni Luh Gede Ratna Juliasih; Irza Sukmana; Wasinton Simanjuntak; Sutopo Hadi
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

In medicinal field, delivery agent is a very important substance to improve the efficiency of drug used by improving the stability and preventing the degradation of drug during the medical treatment. Due to these important roles of the drug delivery agent, the search of effective agent is continuously in progress. In this respect, this current research was carried out to synthesize cellulose–polylactic acid (cellulose-PLA), as a potential delivery agent of rifampicin for the curing of tuberculosis. Cellulose was isolated from cassava bagasse, while PLA was obtained from commercial supplier. The two raw materials were used to synthesize cellulose–PLA in 3.5% HCl as solvent under magnetic stirring. The product obtained was then characterized by Fourier-Transform Infrared spectroscopy (FTIR), Particle-Size Analysis (PSA), and Scanning Electron Microscopy (SEM). The FT-IR result showed the presence of hydroxy (3446 to 3429 cm−1) and carbonyl (1757 to 1759 cm−1), confirming the formation new bond between cellulose and PLA. The PSA characterization displays a particle-sizes of PLA are in the range of 960–92780 nm, while cellulose–PLA are in the range of 100–17730 nm demonstrating that cellulose-PLA combined to form more compact structures. The results of SEM analysis indicate the distinct feature of cellulose-PLA, and combination of the features in the cellulose and PLA image. The results of the dissolution test carried out two different concentrations of rifampicin revealed that the optimum dissolution (8.42%) was achieved with cellulose–PLA of 0.3%, dissolution time of 12 h, and pH of 7.4.

Subclasses of Analytic Functions with Negative Coefficients Involving q-Derivative Operator Andy Liew Pik Hern; Aini Janteng; Rashidah Omar
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Let A denote the class of functions f which are analytic in the open unit disk U. The subclass of A consisting of univalent functions is denoted by M. In this paper, we also consider a subclass of M which is denoted by V, consisting of functions with negative coefficients. In addition, this paper also studies the q-derivative operator. By combining the ideas, this paper introduced three subclasses of A with negative coefficients involving q-derivative. Furthermore, the coefficient estimates, growth results and extreme points were obtained for all of these classes.

Antioxidant and Antibacterial Activities of Endophytic Fungi Extracts of Syzygium zeylanicum Syarifah; Elfita; Hary Widjajanti; Arum Setiawan; Alfia Rahma Kurniawati
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Syzygium zeylanicum, one of the other therapeutic plants found in Indonesia, is used to treat various ailments, such as antimicrobial, anti-inflammatory, antioxidant, arthritis, antidiabetic, mosquitocidal, antitumor, and anti-rheumatic agents. The massive use of plant extracts has caused the development of isolation of bioactive compounds thru their endophytic. The present research aimed to obtain endophytic fungal isolates from the stem bark and leaves of Jambu nasi-nasi (S. zeylanicum) and analyze endophytic fungal extracts’ antioxidant and antibacterial activity. Endophyte identification was performed morphologically, and isolates with high biological activity were molecularly characterized. The antibacterial activity was evaluated by the disc diffusion method, and the antioxidant activity was evaluated by the DPPH method. In total, 10 endophytic fungi were isolated and identified as Phialemonium sp. (Code SZT3), Acremonium sp. (Code SZT4), Trichoderma aureoviridae (Code SZT5), Trichoderma koningi (Code SZT7), Phytium torulosum (Code SZL1), Phytium zingiberum (Code SZL2), Septonema sp. (Code SZL3), Lasiodiplodia pseudotheobromae (Code SZL4), Volutella cilliata (SZL5), and Trichophyton mentagrophytes (Code SZL7). Isolate SZL4 gave activity the highest antioxidant (IC50 = 3.30 ????g/mL) and strong antibacterial activity against four pathogens bacterial (S. thypi, B. subtilis, S. aureus, and E. coli). The potential endophytic fungi based on molecular analysis was Lasiodiplodia pseudotheobromae with accession number OK668257. These endophytic fungi can be developed into new sources of antibacterial and antioxidant bioactive compounds through further studies.

Modification of Mg/Al-LDH Intercalated Metal Oxide (Mg/Al-Ni) to Improve The Performance of Methyl Orange and Methyl Red Dyes Adsorption Process Nova Yuliasari; Arini Fousty Badri; Alfan Wijaya; Patimah Mega Syah Bahar Nur Siregar; Amri; Mardiyanto; Risfidian Mohadi; Aldes Lesbani
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Modification of Mg/Al-LDH intercalated metal oxide (Mg/Al-Ni) was successfully formed by the coprecipitation method at pH 10, which is indicated by the XRD diffraction, FTIR spectrum, and BET analysis. Mg/Al-LDH increased surface area after intercalated Ni from 8.621 m2/g to 9.821 m2/g and improved performance in process regeneration which can be used in the three cycles. Mg/Al-LDH after intercalated metal oxide (Ni) increases adsorption capacity of is 69.930 mg/g to 71.429 mg/g for methyl orange (MO) and 77.519 mg/g to 98.039 mg/g for methyl red (MR). Equilibrium time on the adsorption process occurred at 90 minutes with adsorption kinetics followed pseudo-second-order (PSO). Thermodynamic parameters indicate that the adsorption process is spontaneous and endothermic with the physical adsorption process.

Susceptible Vaccine Infected Removed (SVIR) Model for COVID-19 Cases in Indonesia Hanna Arini Parhusip; Suryasatriya Trihandaru; Bernadus Aryo Adhi Wicaksono; Denny Indrajaya; Yohanes Sardjono; Om Prakash Vyas
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Analysis of data on COVID-19 cases in Indonesia is shown by using the Susceptible Vaccine Infected Removed (SVIR) in this article. In the previous research, cases in the period March-May 2021 were studied, and the reproduction number was computed based on the Susceptible Infected Removed (SIR) model. The prediction did not agree with the real data. Therefore the objective of this article is to improve the model by adding the vaccine variable leading to the new model called the SVIR model as the novelty of this article. The used data are collected from COVID-19 cases of the Indonesian population published by the Indonesian government from March 2020-April 2022. However, the vaccinated persons with COVID-19 cases have been recorded since January 2022. Therefore the models rely on the period January 2021-March 2022, where the parameters in the SIR and SVIR models are determined in this period. The method used is discretizing the models into linear systems, and these systems are solved by Ordinary Least Square (OLS) for time-dependent parameters. It is assumed that the birth rate and death rate in the considered period are constant. Additionally, individuals who have recovered from COVID-19 will not be infected again, and vaccination is not necessarily twice. Furthermore, individuals who have been vaccinated will not be infected with the COVID-19 virus. The SVIR model has captured 3 waves of COVID-19 cases that are appropriate to the real situation in Indonesia from January 2021-March 2022. Additionally, the reproduction numbers as functions of time have been generated. The fluctuations of reproduction numbers agree with the real data. For further research, different regions such as districts in Java and other islands will also be analyzed as the implication of this research.

Evaluate All The Order of Every Element in The Higher Even, Odd, and Prime Order of Group for Composition Md. Abdul Mannan; Halima Akter; Md. Amanat Ullah
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

This paper aims to treat a study on the order of every element in the higher even, odd and prime order of group for composition. In fact, express order of a group and order of an element of a group in real numbers. Here we discuss the higher order of groups in different types of order, which will give us practical knowledge to see the applications of the composition. In order to find out the order of an element am∈G in which an= e= identity element, then find the least common multiple (i.e.(LCM))= λ) of m and n. The least common multiple of two numbers is the "smallest non-zero common number," which is a multiple of both the numbers. So O(am )= λ/m. Also, if G is a finite group, n is a positive integer, and a∈G then the order of the products na. When G is a finite group, every element must have finite order, but the converse is false. There are infinite groups where each element has finite order. Finally, find out the order of every element of a group in different types of the higher even, odd and prime order of group for composition.

Enumerate the Number of Vertices Labeled Connected Graph of Order Seven Containing No Parallel Edges Muslim Ansori; Wamiliana; Fitriani; Yudi Antoni; Desiana Putri
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

A graph that is connected G(V,E) is a graph in which there is at least one path connecting every two vertices in G; otherwise, it is called a disconnected graph. Labels or values can be assigned to the vertices or edges of a graph. A vertex-labeled graph is one in which only the vertices are labeled, and an edges-labeled graph is one in which only edges are assigned values or labels. If both vertices and edges are labeled, the graph is referred to as total labeling. If given n vertices and m edges, numerous graphs can be made, either connected or disconnected. This study will be discussed the number of disconnected vertices labeled graphs of order seven containing no parallel edges and may contain loops. The results show that number of vertices labeled connected graph of order seven with no parallel edges is N(G7,m, g)l= 6,727×Cm6; while for 7≤g≤ 21, N(G7,m, g)l= kg C(m−(g−6))g−1, where k7 =30,160, k8 = 30,765, k9=21,000, k10 =28,364, k11= 26,880, k12=26,460 , k13 = 20,790, k14 =10,290, k15 = 8,022, k16 = 2,940, k17 =4,417, k18 = 2,835, k19 =210, k20 = 21, k21= 1.

Crystal Engineering Approach in Physicochemical Properties Modifications of Phytochemical Dhea Sultana Lutfiyah; Lili Fitriani; Muhammad Taher; Erizal Zaini
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Phytochemicals have been used to reduce the risk of diseases and maintain good health and well-being. However, most phytochemicals have a limitation in their physicochemical properties, which can be modified by reforming the shape of the crystals. Therefore, crystal engineering is a promising approach to optimize physicochemical characteristics of the active pharmaceutical ingredients (APIs) in a phytochemical without altering its pharmacological efficacy. Hence, this paper reviews current strategies for the use of crystal engineering to optimize physicochemical properties of phytochemicals, which is followed by the design of the synthesis and characterization of particular phytochemicals, including piperine (PIP), quercetin (QUE), curcumin (CUR), genistein (GEN), and myricetin (MYR). The literature indicates that crystal engineering of multicomponent crystals (MCCs) enhances phytochemical physicochemical properties, including solubility, dissolution rate, stability, and permeability. The MCCs provide a lower lattice energy and noncovalent bonding, which translate into lower melting points and weak intermolecular interactions that generate greater solubility, higher dissolution rate, and better stability of the APIs. Nevertheless, the absence of reported studies of phytochemical crystal engineering leads to a lack of variation in the selection of coformers, methods of preparation, and improvement of physicochemical properties. Therefore, more extensive evaluation of the design and physicochemical characteristics of phytochemicals using MCCs is necessary and manifests the opportunity to enhance the application of phytochemicals in the pharmaceutical industry.

Formulation and Evaluation of Solid Lipid Nanoparticles Loading Erythromycin Ethylsuccinate by Heating Emulsification and Homogenization Methods Mardiyanto Mardiyanto; Budi Untari; Ady Mara; Sadakata Sinulingga; Nirwan Syarif; Gustina Emilia Ningsih
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

The pandemic period has caused antibiotics highly recommended to cure infections. The use of macrolide antibiotics has greatly increased recently due to outbreaks of diseases that attack the human respiratory tract all of part of the world. One member of the macrolide group is erythromycin ethyl succinate which has low solubility in water. Therefore, this study aims to convert erythromycin ethyl succinate into lipid nanoparticles in an attempt to increase solubility. The method for the formation of nanoparticles is heating emulsification and homogenization. The results obtained in the form of formula 1 (F1) showed the percent encapsulation of 85.688±0.30641. The physical properties were that it has a size of 398.9±1.4 nm, a PDI of 0.3895±0.0015, and zeta potential of -17.45±0.15 mV respectively. The stability was determined by an accelerated test by the influence of extreme temperature and mechanics affecting the stability of the particles as an indication of decreasing the pH and particle precipitation. The solubility of erythromycin ethyl succinate in the form of lipid nanoparticles was increased in a comparison with the pure substance of erythromycin ethyl succinate.

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