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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 17 Documents
Search results for , issue "Vol. 7 No. 3 (2022): July" : 17 Documents clear
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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2154.038 KB) | DOI: 10.26554/sti.2022.7.3.400-408

Abstract

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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (623.76 KB) | DOI: 10.26554/sti.2022.7.3.333-343

Abstract

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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (744.732 KB) | DOI: 10.26554/sti.2022.7.3.392-399

Abstract

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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1878.126 KB) | DOI: 10.26554/sti.2022.7.3.353-371

Abstract

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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1259.916 KB) | DOI: 10.26554/sti.2022.7.3.320-326

Abstract

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.
Preparation of Hydrochar from Salacca zalacca Peels by Hydrothermal Carbonization: Study of Adsorption on Congo Red Dyes and Regeneration Ability Mauizatul Hasanah; Alfan Wijaya; Fitri Suryani Arsyad; 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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3498.283 KB) | DOI: 10.26554/sti.2022.7.3.372-378

Abstract

Hydrochar of Salacca zalacca peels (HC-SP) is prepared by hydrothermal carbonization treatment of Salacca zalacca peels (SP) obtained from local fruits at Palembang, South Sumatera, Indonesia, with the resulting yield weight reaching 90%. Materials are characterized using the XRD diffraction, FTIR spectrum, and SEM-EDX. The XRD pattern shows the characteristics of the formation of amorphous compounds. The FTIR spectrum confirms the presence of functional groups O-H, C-H, C=C, and C-O. Data of SEM-EDX show that materials have heterogeneous morphologies, form aggregates, and in HC-SP materials there is an increase in carbon content from the initial material. The capacity of SP in the congo red (CR) adsorption process is 33.003 mg/g and increases to 133.333 mg/g in HC-SP. The maximum dye adsorbed was achieved at pH 4. The adsorption kinetics followed PSO with the equilibrium adsorption occurring at 90 minutes, and the adsorption isotherm followed the Langmuir isotherm with the value of R2 closer to the value of 1. A positive 4H value indicated that the adsorption is an endothermic process. In contrast, an 4S value suggested that the degree of irregularity in the adsorption process is small in large concentrations. Based on data regeneration ability, materials of SP and HC-SP can be used in the three cycles regeneration process of the CR adsorption process. The adsorption process of CR occurs physically and chemically based on enthalpy values and FT-IR data after being adsorbed with CR.
Catalytic Oxidative Desulfurization of Dibenzothiophene by Composites Based Ni/Al-Oxide Nur Ahmad; Alfan Wijaya; Amri; Erni Salasia Fitri; Fitri Suryani Arsyad; 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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1788.962 KB) | DOI: 10.26554/sti.2022.7.3.385-391

Abstract

In the present study, composite layer double hydroxide-metal oxide (Ni/Al-TiO2 and Ni/Al-ZnO) was successfully prepared and used as catalyst of oxidative desulfurization of dibenzothiophene. Characterization of catalyst was used XRD, FTIR, and SEM-EDS. The structure of Ni/Al-LDH, TiO2, and ZnO in composite Ni/Al-TiO2 and Ni/Al-ZnO was consistent, which also indicated that the preparation of composite did not change the form of precursors. FTIR spectra of Ni/Al-TiO2 and Ni/Al-ZnO absorption band at 3398, 1639, 1339, 832, 731, and 682 cm−1. The catalysts have an irregular structure, TiO2 and ZnO adhere to the surface of Ni/Al LDH. The percent mass of Ti and Zn on the composite at 29.3% and 18.2%, respectively. The acidity of Ni/Al LDH increased after being composited with TiO2 and ZnO. The optimum reaction time, dosage catalyst, and temperature were 30 min, 0.25 g, and 50°C, respectively, and n-hexane as a solvent. The percentage conversion of dibenzothiophene on Ni/Al-LDH, TiO2, ZnO, Ni/Al-TiO2, and Ni/Al-ZnO were 99.44%, 91.92%, 95.36%, 99.88%, and 99.90%, respectively. The catalysts are heterogeneous system and the advantage is that can be used for reusability. After 3 times catalytic reactions, the conversion of dibenzothiophene still retains more than 80%, even Ni/Al-TiO2 and Ni/Al-ZnO composites still 97.79% and 98.99%, respectively.

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