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INDONESIA
Science and Technology Indonesia
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
Arjuna Subject : -
Articles 551 Documents
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Biogenic Silica Extracted from Salacca Leaves Ash for The Adsorption of Salycilic Acid Is Fatimah; Faiha Ulfiyani Zaenuri; Lolita Narulita Doewandono; Amri Yahya; Putwi Widya Citradewi; Suresh Sagadevan; Won-Chun Oh
Science and Technology Indonesia Vol. 6 No. 4 (2021): October
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.2021.6.4.296-302

Abstract

Extraction of biogenic silica from Salacca leaves ash and it’s utilization as adsorbent for salycilic acid has been successfully conducted. The caustic extraction by Refluxing the ash in NaOH followed by slow titration using acid produced the silica gel, and in order to evaluate the physicochemical character for adsorption purpose, the sintering of the dried gel was varied at 300, 400 and 500oC. Instrumental analysis of x-ray diffraction, scanning electron microscopy, gas sorption analysis, and Fourier transform infrared spectroscopy were employed. The kinetics of the salycilic acid adsorption was investigated in a batch adsorption system and the quantitative analysis was based on UV–Vis spectrometry. The results showed that the produced silica exhibited adsorption capability for salycilic acid in an aqueous solution. At varied sintering temperature, the highest adsorption capacity and affinity was achieved by temperature of 500oC, and the adsorption kinetics obeyed the Langmuir isotherm. The varied pH for adsorption suggested neutral pH is the most feasible compared to the acidic and basic conditions.
Determining The Number of Connected Vertex Labeled Graphs of Order Seven without Loops by Observing The Patterns of Formula for Lower Order Graphs with Similar Property Muslim Ansori; Wamiliana; Fadila Cahya Puri
Science and Technology Indonesia Vol. 6 No. 4 (2021): October
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.2021.6.4.328-336

Abstract

Given n vertices and m edges, m ≥ 1, and for every vertex is given a label, there are lots of graphs that can be obtained. The graphs obtained may be simple or not simple, connected or disconnected. A graph G(V,E) is called simple if G(V,E) not containing loops nor paralel edges. An edge which has the same end vertex is called a loop, and paralel edges are two or more edges which connect the same set of vertices. Let N(G7,m,t) as the number of connected vertex labeled graphs of order seven with m vertices and t (t is the number edges that connect different pair of vertices). The result shows that N(G7,m,t) = ct C (m−1) t−1, with c6=6727, c7=30160 , c8=30765, c9=21000, c10=28364, c11=26880, c12=26460, c13=20790, c14=10290, c15= 8022, c16=2940, c17=4417, c18=2835, c19=210, c20= 21, c21=1.
Analysis of Information Service Pricing Scheme Model Based on Customer Self-Selection Indrawati; Fitri Maya Puspita; Resmadona; Evi Yuliza; Oki Dwipurwani; Sisca Octarina
Science and Technology Indonesia Vol. 6 No. 4 (2021): October
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.2021.6.4.337-343

Abstract

This study attempts to analyze pricing schemes with monitoring cost and marginal cost for perfect substitute and quasi-linear utility functions for achieving Internet service Provider (ISP) in gaining benefit. Two types of customers analyzed, namely customers who are heterogeneous (both high-end and low-end) as well as heterogeneous customers (high-demand and low-demand) based on Flat-fee, usage-based, and two-part tariff are the three types of pricing methods employed. The results show that usage-based pricing schemes gain maximum profit optimal for heterogeneous customers (high-end and low-end), while for heterogeneous customers (high-demand and low-demand) type of pricing scheme two-part tariff obtains maximum profit optimal. The results of this study are more directed to the lemma of the perfect substitute utility function which compares the lemma of heterogeneous customers. This model was solved using LINGO 13.0 software and ISP to get maximum profit.
Physical and Mechanical Properties of Bamboo Oriented Strand Board Prepared from Alkali-Immersed Strands Sena Maulana; Tarmizi Taher; Aditya Rianjanu; Melany Febrina; Sarah Agustina; Rio Ardiansyah Murda; Wahyu Hidayat; Yazid Bindar
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.2023.8.1.1-8

Abstract

In this work, the physical and mechanical properties of bamboo oriented strand board (BOSB) prepared from alkali-immersed strands were examined. The Dendrocalamus asper strands were modified with alkali treatment by immersing them in 1% sodium hydroxide solution for 1, 2, and 3 hours. Three-layers BOSBs (30 x 30 x 0.9 cm3) were prepared using phenol-formaldehyde (PF) adhesive of 8% concentration and 1% paraffin. According to JIS A 5908:2003 Standard, the physical and mechanical characteristics of BOSB were evaluated (JSA, 2003). The study showed that alkali treatment improved the dimensional stability of BOSB. Immersion in 1% sodium hydroxide solutions enhanced internal bonding (IB). The longer the immersion time, the better the WA, TS, and IB values. However, alkali treatment decreased the bending strength, i.e., modulus of elasticity (MOE) and modulus of rupture (MOR). The physical and mechanical properties of all BOSBs met the commercial standard, except the BOSBs prepared from strand with alkali immersion treatment by 1% sodium hydroxide solution for 3 hours. Alkali immersion treatment of D. asper strands for producing BOSB for 1-2 hours was still acceptable. The results could provide an alternative method to produce high-performance oriented strand board using bamboo as the raw materials.
Majority Voting as Ensemble Classifier for Cervical Cancer Classification Anita Desiani; Endang Sri Kresnawati; Muhammad Arhami; Yulia Resti; Ning Eliyati; Sugandi Yahdin; Titania Jeanni Charissa; Muhammad Nawawi
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.2023.8.1.84-92

Abstract

Cervical cancer is one of the deadliest female cancers. Early identification of cervical cancer through pap smear cell image evaluation is one of the strategies to reduce cervical cancer cases. The classification methods that are often used are SVM, MLP, and K-NN. The weakness of the SVM method is that it is not efficient on large datasets. Meanwhile, in the MLP method, large amounts of data can increase the complexity of each layer, thereby affecting the duration of the weighting process. Moreover, the K-NN method is not efficient for data with a large number of attributes. The ensemble method is one of the techniques to overcome the limitations of a single classification method. The ensemble classification method combines the performance of several classification methods. This study proposes an ensemble method with the majority voting that can be used in cervical cancer classification based on pap smear images in the Herlev dataset. Majority Voting is used to integrate test results from the SVM, MLP, and KNN methods by looking at the majority results on the test data classification. The results of this study indicate that the accuracy results obtained in the ensemble method increased by 1.72% compared to the average accuracy value in SVM, MLP, and KNN. for sensitivity results, the results of the ensemble method were able to increase the sensitivity increase by 0.74% compared to the average of the three single classification methods. for specificity, the ensemble method can increase the specificity results by 3.4%. From the results of the study, it can be concluded that the ensemble method with the most votes is able to improve the classification performance of the single classification method in classifying cervical cancer abnormalities with pap smear images.
Characteristics and Substrate Specificity of Semi-Purified Bacterial Protease of Bacillus thuringiensis HSFI-12 with Potential as Antithrombotic Agent Dina Ferdiani; Dewi Seswita Zilda; Muhammad Ardi Afriansyah; Stalis Norma Ethica
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.2023.8.1.9-16

Abstract

Commercial proteases, such as Nattokinase (NK), Staphylokinase (SAK), and Streptokinase (SK) play an important role in the destruction of thrombus, the main cause of death in cardiovascular disease. The latest technology combining enzymes with certain drugs is the target of new research in the thrombolytic area. The first step is to develop protease from Bacillus thuringiensis HSFI-12 bacteria as an antithrombotic agent, characterization of the bacterial enzyme is necessary. This study aims to determine the specificity of protease from Bacillus thuringiensis HSFI-12 to explore its potential as an antithrombotic agent in terms of anticoagulant and fibrinolytic activities. The molecular weight and specificity of bacterial protease were determined with a zymographic method with casein as substrate. Bacillus thuringiensis HSFI-12 was first cultured on Nutrient Agar (NA) media and then on Skim Milk Agar (SMA) media. The obtained crude protease from Skim Milk Broth (SMB) was then concentrated as dialysate. Both crude and dialysate proteases were tested for their specific activity, as well as anticoagulant and fibrinolytic activities. Next, the dialysate’s molecular weight and specificity on the casein substrate were investigated using the zymographic method. As result, protease activity in crude form is lower than that in dialysate, which was 0.5570 ± 0,004 U/mL and 2.1767 ± 0,005 U/mL, respectively. The molecular weight of the obtained bacterial protease was between 117 – 133 kDa and the enzyme is capable of degrading casein as shown on the zymogram. Overall, both crude and dialysate proteases of Bacillus thuringiensis HSFI-12 show potential as an antithrombotic agent for exhibiting anticoagulant and antiplatelet activities. Yet, it could not exhibit direct fibrinolytic activity implying the possibility that the enzyme plays a role as a plasminogen activator, which can dissolve fibrin by activating plasmin.
Tablet Formulation with Galactomannan Binding Agent and Acute Toxicity Test from Terminalia catappa L. Nilsya Febrika Zebua; Tandra Alexandro; Virda Widya Pratiwi; Syarifah Nadia; Supran Hidayat; Muflihah Fujiko; Muharni Saputri; Tedy Kurniawan Bakri; Nerdy
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.2023.8.1.129-136

Abstract

Ketapang is one of the many medicinal plant species that grow in Indonesia and is used to treat various diseases. Ketapang leaves contain flavonoids, tannins, saponins, and terpenoids that have anti-inflammatory, antioxidant, antiviral, and antimicrobial properties. This study aimed to determine the LD50 and histopathology of Liver and kidney damage before the formulation of tablets containing galactomannan-binding agents. The toxicity determination method was carried out in vivo in experimental animals at doses of 4g/kg BW, 8g/kg BW and 16g/kg BW, and Liver and kidney histopathology was carried out before formulation into tablet preparations using the wet granulation method with various concentrations of binders and disintegrants, namely F1(8:0), F2(0:8), F3(4:4), F4(2:6), and F5(6:2). The results of the toxicity test showed an LD50 of 15.9959, liver damage at a dose of 4 g/kg BW hepatocyte karyorrhexis cells, central vein constriction, sinusoidal dilatation, a dose of 8 g/kg BW hepatocyte karyorrhexis, significant venous congestion, sinusoidal dilatation, a dose of 16 g/kg BW hepatocyte cells, karyolysis, dilated central veins, and dilated sinusoids. The results of the tablet mass preformulation test meet the requirements: the flow time test was 1.48-2.14 g/second, the angle of repose test was 24.60°-30.60°, and the tab index test was 5.33%-9.33%. The results of the tablet evaluation test were as follows: the tablet hardness test was 3.8-8.6 kg, the tablet friability test was 0.167-0.64%, and the tablet disintegration time test was 29.06-107.51 minutes.
The Risk Cluster in Type 2 Diabetes Mellitus Based on Risk Parameters Using Fuzzy C-Means Algorithm Marhamah; Sugiyarto Surono; Endang Darmawan
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.2023.8.1.17-24

Abstract

The prevalence of type 2 diabetes mellitus increases every year. In the long term, type 2 diabetes mellitus can lead to complications of other diseases. This study aimed to analyze the risk cluster for type 2 diabetes mellitus based on risk parameters using the Fuzzy C-Means algorithm. The benefit of analyzing the risk cluster as an initial screening to prevent the occurrence of type 2 diabetes mellitus. This study used 905 subjects’ data consisting of 562 males and 343 females. After the data preprocessing, the optimal number of clusters was determined using a Fuzzy C-Means algorithm process. Subsequently, the Pearson correlation test was conducted to determine the correlation between the risk parameters of type 2 diabetes mellitus and the cluster results. The study resulted in 2 risk clusters, subjects in cluster 1 were older than 60 years (34.1%), had a family history of type 2 diabetes mellitus (62.7%), had hypertension (55.4%), routinely took medicines (73.5%), undertook physical activity for less than half an hour (40.5%), and had a high blood pressure level (53.5%). The Pearson correlation test found that age, regular medication use, hypertension and blood pressure level all seem to have significant correlations with cluster outcomes. The risk cluster of type 2 diabetes mellitus was separated into two clusters using Fuzzy C-Means algorithm, namely the high-risk cluster and the low-risk cluster.
Electrochemical Performance of Galvanic Cell with Silver Coated Cathode in One Compartment System Using Seawater as Electrolyte Gurum Ahmad Pauzi; Ahmad Saudi Samosir; Sri Ratna Sulistiyanti; Wasinton Simanjuntak
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.2023.8.1.25-31

Abstract

This research was carried out to evaluate the electrochemical performance of a galvanic cell using seawater as an electrolyte. The cell was designed to have a volume of 200 mL and equipped with Zn as an anode and Ag-coated Cu as a cathode (Cu(Ag)-Zn system) in order to suppress the corrosion of Cu. As a comparison, the same experiment with the use of uncoated Cu as a cathode (Cu-Zn system) was also conducted. To conduct the experiment, a system was assembled by connecting 20 cells in series and placed in a closed container filled with seawater. The experiment was run for 72 hours, divided into three 24-hour cycles, by replacing the seawater every 24 hours. The performance of the system was evaluated in terms of open circuit voltage, close circuit voltage, current, light intensity, internal resistance, and power. The experimental results show that the corrosion rate of Cu coated with silver was smaller than that of uncoated Cu. Compared to the performance of the Cu-Zn system, it was also found that the Cu(Ag)-Zn system produced higher power and light intensity, which is in accordance with its smaller internal resistance. The overall experimental results indicate better performance of Cu(Ag)-Zn system and this better performance is attributed to the significantly lower corrosion rate of Cu(Ag) cathode which signifies the role of Ag layer to protect the Cu from attack by seawater. As a result, the Cu(Ag)-Zn system maintained the cathode corrosion rate with a ratio of 0.19. The percentage decrease of the OCV of the Cu(Ag)-Zn system was 6.14%, the CCV on the third day was 0.99%, the current was 36.68%, and the power was 37.83%.
Determination of (+)-Catechin and Antioxidant Activity in Faloak (Sterculia quadrifida R. Br) Stem Bark Infusion Audrey Gracelia Riwu; Jusak Nugraha; Djoko Agus Purwanto; Erwin Astha Triyono
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.2023.8.1.59-65

Abstract

Oxidative stress is a condition that can damage human cells and tissues and has been linked to a number of illnesses, including cancer, cardiovascular disease, autoimmune disorders, and neurological diseases. Oxidative stress conditions can be brought on by pollution, radiation exposure, and an unhealthy lifestyle. Antioxidants are substances that can be used to both prevent and treat oxidative stress. This study aimed to identify and quantify (+)-catechin levels and antioxidant activity of the stem bark of Sterculia quadrifida R. Br extracted by the infusion method, a method similar to traditional medicine processing generally in the community. Determination of (+)-catechin and antioxidant activity of S. quadrifida were evaluated by HPLC and DPPH assay, respectively. Quantification of (+) catechin content by HPLC system with wavelength 280 nm and antioxidant activity by spectrophotometry method with wavelength 517 nm. The results show that the mean value of (+)-catechin level was 7.786% and the IC50 value of the antioxidant activity was 51.5 ug/mL having a moderate antioxidant activity category. S. quadrifida stem bark infusion can be utilized as a medication candidate for the prevention or treatment of a variety of disorders caused by oxidative stress.

Page 22 of 56 | Total Record : 551

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