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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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The Addition of Red Dragon Fruit and Lemon Peels for the Improvement of Fermented Beverage Products Sofi Nabila; Arie Srihardyastutie; Sasangka Prasetyawan; Aulanni’am; Rurini Retnowati
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.2023.8.1.100-107

Abstract

Coconut water is part of the coconut fruit, that has bioactive compounds that are thought to own high inhibitor activity to the presence of tannin compounds. However, this compound is antinutritional because it can interfere with macromolecule out there within the body. Considering chance of tannins, these parts are often reduced by fermentation techniques using lactic acid bacteria. This analysis aims to review the addition of dragon fruit and lemon peels in fermentation coconut water using lactic acid bacteria in order to reduce tannin levels and its potential capability as antioxidants. Coconut water fermented drink was prepared by fermentation technique using lactic acid bacteria with the addition of variations in mass of dragon fruit peel and lemon peel consisting of 5 treatments. The optimum conditions for fermentation of coconut water were determined from the decrease in tannin levels, total acid, and the highest total lactic acid bacteria. The optimum conditions for fermentation of coconut water were then tested using an HPLC instrument. Finally, the antioxidantactivity was tested using the FRAP (Ferric Reducing Antioxidant Power) method. The results showed that the addition of dragon fruit and lemon peels in fermented coconut water can reduce tannin levels, can increase total acid levels and the number of lactic acid bacteria formed in coconut water fermented drinks. The best proportion was obtained in the treatment of rasio of mass 1:2 resulted in the highest decrease in tannin content of 83.94 mg/100 g followed by a total acid value of 1.13% and the number of lactic acid bacteria was 8.4 × 107 CFU/mL. The HPLC chromatogram showed that fermented coconut water using lactic acid bacteria contained organic acid compounds such as lactic acid, acetic acid, and ascorbic acid. The highest antioxidant activity test was 82.37 mmgAAE/g. This study confirmed that the addition of dragon fruit and lemon peels affected the degradation of tannins and increased antioxidant activity during coconut water fermentation using lactic acid bacteria.
Fe3O4-SiO2-Alginate Photocatalyst for Textile Dyes Waste Degradation Sri Wardhani; Herdian Akbar Mardiansyah; Danar Purwonugroho
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.2023.8.1.108-115

Abstract

Fe3O4 is a photocatalyst that is used to degrade textile dye waste which can be collected and reused. Fe3O4 was prepared by coprecipitation method, then impregnated with SiO2 and sodium alginate. The purposes of this study were to investigate the degradation of textile dye waste using a Fe3O4-SiO2-alginate photocatalyst, to examine the light and dark test of photocatalyst under the influence of concentration and irradiation time. The type of light used was a 14.5-watt Philips LED lamp with a wavelength of 400-640 nm. Photocatalyst characterizations were conducted using FTIR, UV-Vis DRS, and XRD. The light and dark test of photocatalyst was carried out by photodegradation of textile dye waste with 0.5 g of photocatalyst with concentrations of 5%, 10%, and 15% and irradiation times were varied for 60, 90, 120 min. The degradation results were measured by calculating the COD value. The results of characterization by FTIR showed that the photocatalyst Fe3O4-SiO2-Alginate had absorption at wavelengths of 637.56 cm−1 and 3365.86 cm−1 which indicated the Fe-O-Si functional group and O-H stretching vibration. Results of UV-Vis DRS were analyzed using Origin Pro 2022 and revealed that the band energy gap for Fe3O4 and Fe3O4-SiO2 were 2.20 eV and 1.77 eV, respectively. The XRD results analysis with Match!3 software showed that for Fe3O4 had magnetite phases, while SiO2 had amorphous cristobalite phases. The 15% (w/v) Fe3O4 concentration in the form of powder and granules degraded batik liquid waste by 79.6% and 84.48%, respectively.
Enhanced Effectiveness on Phenol Removal by MgCr-LDH/Microcrystalline Cellulose Composite and Regeneration Study with Green Desorption Reagent Nova Yuliasari; Alfan Wijaya; Risfidian Mohadi; Aldes Lesbani
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.2023.8.1.151-159

Abstract

Modified MgCr-LDH with microcrystalline cellulose (MgCr/MCC) was successfully prepared by the coprecipitation method and characterized using XRD, FT-IR, and BET analyses. MgCr/MCC showed an increase in surface area from 21.51 to 26.056 m2/g. The material was tested as an adsorbent for the removal of phenol. MgCr/MCC showed an increase in adsorption capacity from the initial material of 24.631 to 58.480 mg/g. The optimum pH was at pH 9 and the adsorption process’s equilibrium time is 70 minutes. The correlation coefficients on the kinetics and isotherm parameters show that phenol removal follows the pseudo second order (PSO) and Langmuir models with spontaneous and endothermic adsorption processes. The regeneration ability of MgCr/MCC material using the water-assisted ultrasonic system as a green desorption reagent was 3 cycles with a percent regeneration efficiency of 39.45%.
Adsorption of Phenol from Aqueous Solution Using Zn/Al Layered Double Hydroxides-Cellulose Composite Risfidian Mohadi; Amri; Muhammad Badaruddin; Nur Ahmad; Aldes Lesbani
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.2023.8.1.123-128

Abstract

The successful synthesis and preparation of Zn/Al layered double hydroxide, cellulose, and Zn/Al-cellulose materials were analyzed using XRD, FT-IR, and BET. The diffraction peaks of Zn/Al layered double hydroxide are at 10.3°; 20.3°; 34.8°; and 60.40°, while the diffraction peaks of cellulose are at 15.5°; 22.4°; and 34.5°. Diffraction peaks on Zn/Al layered double hydroxide and cellulose were observed at 3442 cm-1, 1642 cm-1, 1440-1620 cm-1, 1351 cm-1, 1153 cm-1, and 400-800 cm-1. The surface area of the material after the composite increased from 1.968 to 13.615 m2/g. The optimum pH for Zn/Al LDH was pH 4, pH 10 for cellulose, and pH 2 for Zn/Al-cellulose. The isotherm data of Zn/Al LDH and cellulose followed the Freundlich model, while Zn/Al-cellulose followed the Langmuir model. The reuse of adsorbents in the adsorption process can be used up to 3 times.
Interlayer Modification of West Java Natural Bentonite as Hazardous Dye Rhodamine B Adsorption Satria Jaya Priatna; Yusuf Mathiinul Hakim; Sahrul Wibyan; Siti Sailah; Risfidian Mohadi
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.160-169

Abstract

This work reports the modification of West Java natural bentonite as an effective adsorbent for rhodamine B dye. The modification was finished by sodium intercalation at room temperature to get low-energy preparation. Characterization of bentonite-modified adsorbent was used SEM, XRD, FTIR, and BET analysis. The material pore size and surface area were increased by 0.303 nm and 178.710 m2/g on Na-bentonite. The adsorption mechanism conformed well with the Freundlich isotherm model and pseudo-second-order kinetics equations. The adsorption process by thermodynamic analysis was endothermic and advantageous. Under the optimum condition of pH 6 (confirmed by pHpzc), initial dye concentration of 125 mg/L, and the adsorbent dosage of 0.09 g for 65 minutes, the Na-bentonite has a larger adsorption capacity (Qm) of 142.86 mg/g, while the different adsorbent dosages of 0.11 g for 75 minutes, the adsorption capacity of natural bentonite (Qm) reaches 140.85 mg/g. This work provides a method for establishing a low-energy preparation adsorbent of bentonite-based on Na intercalant as a low-cost and valuable adsorbent for waste dye removal.
Antibacterial and Antioxidant Activity of Endophytic Fungi Extract Isolated from Leaves of Sungkai (Peronema canescens) Rian Oktiansyah; Hary Widjajanti; Arum Setiawan; Sakinah Salman Ahmad Nasution; Mardiyanto; Elfita Elfita
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.170-177

Abstract

Sungkai is a plant that is widely found in Indonesia. This plant is often used in traditional medicine so the biotechnology of endophytic fungi is highly needed due to natural resources from plants that have been reduced. This study reported on endophytic fungi found in sungkai leaves and the compound produced. Morphological and molecular identification through phylogenetic tree analysis was carried out to determine the endophytic fungal species found. Potato Dextrose Broth media was used for the cultivation process. Ethyl acetate was used as a solvent for the extraction and the evaporation process used a rotary evaporator. Antioxidant and antibacterial tests were carried out using the DPPH method and paper disc diffusion. Chromatographic techniques were used to isolate the compound and spectroscopic analysis was performed to identify its chemical structure. The results of the morphological and molecular analysis showed Trichoderma asperellum as an endophytic fungus identified. The pure compound obtained from this endophytic fungus was 4-hydroxybenzoic acid. The antioxidant and antibacterial activity showed a strong category (IC50 = 43.88 ????g/mL; MIC 64 ????g/mL). This compound was very likely to be a raw material for new antibiotics and antioxidants through further research with various modifications.
Bi-Univalent Function Classes Defined by Using an Einstein Function and a New Generalised Operator Munirah Rossdy; Rashidah Omar; Shaharuddin Cik Soh
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.195-204

Abstract

Let A be the class of all analytic and univalent functions f (z) = z+Σ∞k=2 akzk in the open unit disc D = {z:|z|<1 }. S then represents the classes of every function in A that is univalent in D. For every f ∈ S, there is an inverse f−1. A function f ∈ A in D is categorised as bi-univalent if f and its inverse g = f−1 are both univalent. Motivated by the generalised operator, subordination principle, and the first Einstein function, we present a new family of bi-univalent analytic functions on the open unit disc of the complex plane. The functions contained in the subclasses are used to account for the initial coefficient estimate of |a2|. In this study, we derive the results for the covering theorem, distortion theorem, rotation theorem, growth theorem, and the convexity radius for functions of the class Ns,m,kλ,α (Σ, E) of bi-univalent functions related to an Einstein function and a generalised differential operator Ds,m,kλ,α f (z). We use the elementary transformations that preserve the class Ns,m,kλ,α (Σ, E) in order to attain the intended results. The required propertiesare then obtained.
Extension of Exponential Pareto Distribution with the Order Statistics: Some Properties and Application to Lifetime Dataset Adewunmi Olaniran Adeyemi; Ismail Adedeji Adeleke; Eno Emmanuella Akarawak
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.265-279

Abstract

The Exponential Pareto (EP) model has been extended by applied and theoretical statisticians for wider applications and new knowledge using different techniques but the Weibull-X technique has not been considered. This article proposed a new extension of the EP model called the Weibull-Exponential Pareto (WEP) distribution to provide better modeling that fits real-life datasets and to explore the statistical theory of order statistics from the proposed distribution. Statistical properties investigated include the Shannon and Renyi entropies; the moments and moment generating function. Distribution of order statistics and the moment of order statistics were derived including the mean and variance of order statistics. WEP distribution has unimodal, decreasing, and increasing failure rates; and it can be negatively or positively skewed and approximately symmetric with the potential for fitting platykurtic, mesokurtic, and leptokurtic lifetime data. The parameters of the distribution were estimated using the method of maximum likelihood estimation (MLE), which was examined for consistency through a simulation study. The performance of the proposed distribution was investigated by application to flood peaks exceedances and some lifetime datasets from engineering. The results from data analysis using the R-software revealed that the WEP distribution has the potential to provide a superior model that fits the three data sets better than some notable existing distributions and previous extensions of the EP model in the literature. The statistical property of order statistics extended in the study established some important results that characterized some notable lifetime distributions in the literature.
Perturbed Trapezoid Like Inequalities Waseem Ghazi Alshanti; Iqbal Mohammad Batiha; Ahmad Alshanty; Amjed Zraiqat; Iqbal Hamzah Jebril; Ma’mon Ahmad Abu
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.205-211

Abstract

In our current research article, based on a general configuration of a 3-step Peano kernel, new versions of integral inequality of Ostrowski’s type are developed for differentiable mappings that have second derivatives belong to L∞. Then we utilized these versions to generate new perturbed trapezoid like inequalities. These new perturbed trapezoid like inequalities are proposed with error bounds smaller than and similar to those reported by previous studies. Moreover, some of the obtained perturbed trapezoid like inequalities reveal the relationship between the Euler-Maclaurin summation and the trapezoidal rule. Finally, certain implementations to numerical composite quadrature rules are provided for completeness.
Profiling of Active Compounds of Extract Ethanol, n-Hexane, Ethyl Acetate and Fraction Ethanol of Star Anise (Illicium verum Hook. f.) and Determination of Total Flavonoids, Total Phenolics and Their Potential as Antioxidants Mighfar Syukur; Masitoh Suryaning Prahasiwi; Nurkhasanah; Sapto Yuliani; Yuliana Purwaningsih; Erwin Indriyanti
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
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.2023.8.2.219-226

Abstract

Profiling of chemical compounds on star anise extract and fractions showed the content and looked for active compounds. The main compounds in alkaloids, flavonoids, saponins, phenolics, and triterpenoid forms were identified based on phytochemical screening. FTIR and GC-MS analysis were used to purify the extract and fractions’ main compounds. After analyzing the main components of extract and fractions, a correlation was made between the total phenolic and flavonoid content. The total phenolic content was determined by adding folincalteau complexing solution converted to gallic acid equivalent (GAE), while the total flavonoid content was determined by AlCl3 complexing solution converted to Quercetin Equivalent (QE). The total phenolic yields for extract ethanol, n-hexane fraction, ethyl acetate fraction, and fraction ethanol were obtained at 106.45, 52.30, 93.46, and 148.97 mgGAE/g, respectively. Then the total flavonoid results were 107.45, 58.94, 148.99, 140.01 mgQE/g. The total content of phenolics and flavonoids illustrated the number of active compounds that have a role as free radical scavengers due to their group. Antioxidant activity was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) on extracts and fractions, with the best IC50 results obtained in the ethanol fraction 0.416 mg/mL.

Page 24 of 56 | Total Record : 551

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