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INDONESIA
Science and Technology Indonesia
Published by ARTS Publishing
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
Arjuna Subject : -
Articles 255 Documents
The Effect of Addition on Pumice and Fiber on Compressive and Fluxural Strength Precast Lightweight Concrete: - Indrayani Indrayani; Andi Herius; Arfan Hasan; Ahmad Mirza
Science and Technology Indonesia Vol. 5 No. 1 (2020): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (960.193 KB) | DOI: 10.26554/sti.2020.5.1.14-17

Abstract

Most of the construction uses concrete as the main building material because concrete has many advantages compared to other materials. Concrete has a high enough weight, various attempts were made to reduce the weight of the concrete for example using lightweight aggregates or concrete made without sand or concrete made hollow Innovations in the development of precast lightweight concrete are urgently needed at this time to support the development of development that is being carried out by the government. From the studies that have been carried out on lightweight concrete and fiber concrete, this research will develop the results of previous studies, namely by combining lightweight concrete and fiber concrete to obtain precast lightweight concrete. This research was conducted to find out how much influence the use of pumice and and fiber on compressive strength and flexural strength of precast lightweight concrete. Variations in the addition of a mixture of pumice with aggregate are divided into 4 comparisons, namely 0: 100, 20: 80, 40: 60, 60: 40, where each mixture is added 0.1% fiber from the volume of concrete, then printed in cube and beam molds. Compressive tests were carried out on the cube and flexural tests were carried out on beams. From the test results was obtained that the addition of pumice to the concrete mixture can cause a decrease in compressive strength of the concrete from 202 kg/cm2 to 129 kg/cm2 whereas with the addition of fiber there is an increase in flexural strength is 24.48 kg/cm2. The specific gravity obtained is 1.664 gr/cm3 so this concrete can be classified into lightweight concrete.
Improved Multi Service-Reverse Charging Models for the Multi Link Internet wireless Using QOS Bit Error Rate QoS Attribute Fitri Maya Puspita; Evi Yuliza; Weny Herlina; Yunita Yunita; Rohania Rohania
Science and Technology Indonesia Vol. 5 No. 1 (2020): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (944.584 KB) | DOI: 10.26554/sti.2020.5.1.6-13

Abstract

n this article, a multi-link internet reverse charging scheme model on a multi-service network isproposed. The previous research seldom discussed the reverse charging scheme on multi linkand multi service network. This pricing scheme is designed with the aim of maximizing serviceprovider profits. Basic costs and the level of service satisfaction provided by the ISP is focusedon this attempt. This optimization problem can be solved using LINGO 13.0 software. Thisproblem was made and was divided into several cases. Thus, the results obtained can be aconsideration for ISPs in determining the price of services that can support an ISP. The improvedmodels that produce the maximum solution is case 3 (α and β as variables) and case 4 (α asvariables and β as parameters).
3-Phase Matheuristic Model in Two-Dimensional Cutting Stock Problem of Triangular Shape Items Putra Bahtera Jaya Bangun; Sisca Octarina; Sisca Puspita Sepriliani; Laila Hanum; Endro Sastro cahyono
Science and Technology Indonesia Vol. 5 No. 1 (2020): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1397.786 KB) | DOI: 10.26554/sti.2020.5.1.23-27

Abstract

Cutting Stock Problem (CSP) is a problem of cutting stocks with certain cutting rules. This study used the data of rectangular stocks, which cut into triangular shape items with various order sizes. The Modified Branch and Bound Algorithm (MBBA) was used to determine the optimum cutting pattern then formulated it into the 3-Phase Matheuristic model which consisted of constructive phase, improvement phase, and compaction phase. Based on the results, it showed that the MBBA produces three optimum cutting patterns, which was used six times, eight times, and four times respectively to fulfill the consumer demand. Then the cutting patterns were formulated into the 3-Phase Matheuristic model whereas the optimum solution was the minimum trim loss for the first, second and third patterns.
Synthesis and Characterization Chitosan-ZnO nanoparticle and Its Application as Antibacterial Agent of Staphylococus aureus ATCC 25923 Ahmad Fatoni; Ensiwi Munarsih; Kadek Asmadi; Nurlisa Hidayati
Science and Technology Indonesia Vol. 5 No. 1 (2020): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1652.629 KB) | DOI: 10.26554/sti.2020.5.1.1-5

Abstract

The synthesis of modified chitosan has been studied. The aims of this research were modification of chitosan with ZnO nanoparticle to form chitosan-ZnO nanoparticle and its application as antibacterial agent of Staphylococus aureus. Characterization of modified chitosan was conducted using FTIR spectroscopy and X-Ray diffractometer. ZnO nanoparticle was synthesized by leaf extract of Sirih hijau (piper betle L) and zinc acetate dihydrate. Modified chitosan was synthesized by chitosan and ZnO nanoparticle. Modified chitosan solution can act as antibacterial agent with paper disk method. The result showed that chitosan can be modified with ZnO nanoparticle and detected at wave number of 3427 cm−1. The crystalline size of ZnO nanoparticle is 16.47 nm. The average inhibition zone of chitosan-ZnO nanoparticle at concentration 10.000, 5.000 and 2.500 ppm are 28.87 ± 0.4 ; 24.93 ± 0.15 and 19.35 ± 0.3 mm respectively.
Evaluating the Technical Feasibility of Retention Basins for Flood Control in Palembang City Febrinasti Alia; Muhammad Baitullah Al Amin; Bimo Brata Aditya; Citra Indriyati
Science and Technology Indonesia Vol. 4 No. 2 (2019): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2199.524 KB) | DOI: 10.26554/sti.2019.4.2.40-51

Abstract

Flood control is one of the prevention methods which involves various engineering sciences and is unique. One of structural flood control methods is retention basin with the goal of containing a certain storm event flow volume and obtaining a specific peak flow reduction. This paper’s objective is to describe how to assess the performance of retention basin physical components quantitatively on seven retention basins in Palembang City. The reference and the parameter used in this research are referred to Drainage Systems Assessment Design (Vadlon, 2011) that is based on Standard Procedure of Retention Basins and Polders Construction according to Public Works Ministry of Cipta Karya Directorate General and the Regulation of Public Work Ministry No.32/PRT/M/2007. The result of the assessment is that there are three retention basins which are in good condition, namely Kambang Iwak Besak (63,9%), Simpang Polda (60,34%), and Kambang Iwak Kecil (56,8%); meanwhile the other four basins are in bad conditions, namely RS. Siti Khodijah (43,01%), Palembang Icon (41,93%), Kemang Manis (7,03%), and Brimob (0,94%). Therefore, the assessment of the retention basins towards its effectiveness on flood controlling and handling priority level is done by hydraulic modeling simulations and GIS. 4. Based on the inundation priority assessment of simulated flood depth and duration, it can be inferred that the retention basin of Kambang Iwak Besak, Kambang Iwak Kecik, Palembang Icon, RS Siti Khodijah, and Kemang Manis have low priority handling level. Meanwhile, Brimob and Simpang Polda retention basins have high priority handling level.
Adsorption of congo red using kaolinite-cellulose adsorbent Santa Oktavia Ginting; Risfidian Mohadi
Science and Technology Indonesia Vol. 2 No. 2 (2017): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (747.113 KB) | DOI: 10.26554/sti.2017.2.2.29-36

Abstract

Kaolinite was impregnated with cellulose extracted from rubber wood fibers has been done. The product of impregnated kaolinite-cellulose was characterized using FT-IR spectrophotometer. Furthermore, the impregnation results are used as an adsorbent of Congo red. Adsorption of Congo red was also studied the kinetic and thermodynamic parameters. The results of characterization using FT-IR spectrophotometer shows the process of impregnation was successfully conducted. It was indicated that the presence wavenumber at 910.4 - 918.12 cm-1 and 1033.85 cm-1 become 1026.13 cm-1 and the existence of vibration at wavenumber 2931.8 cm-1. The pH of adsorption was adjusted to 4 before the adsorption process. The adsorption process of cellulose impregnated kaolinite shows the rate of adsorption (k) of 0.002 min-1, the adsorption reviews largest capacity (b) at 50 °C was 500 mol/g. The greatest adsorption energy (E) at 40 °C is 11:09 kJ/mol. The enthalpy value (ΔH) and entropy (ΔS) decreased with increasing Congo red dye concentration. Keywords: kaolinite, cellulose, impregnation, Congo red
Preparation of polyoxometalate compound (NH4)6(β-P2W18O62)/SiO2 by sol-gel method and its characterization Osin Restinawaty Tambunan; Risfidian Mohadi
Science and Technology Indonesia Vol. 2 No. 1 (2017): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (404.805 KB) | DOI: 10.26554/sti.2017.2.1.1-8

Abstract

Preparation of polyoxometalate compound of (NH4)6(β-P2W18O62)nH2O supported with silica derived from the hydrolysis of tetraethyl orthosilicate by sol-gel method has been conducted. The compound was synthesized and characterized using FT-IR spectrophotometer, crystallinity using XRD analysis and the determination of acidity via quantitatively and qualitatively. Qualitative analysis was performed using ammonia and pyridine adsorption and quantitative analysis using potentiometric titration. FT-IR spectrum of (NH4)6(β-P2W18O62)nH2O appeared in wavenumber 786.96 cm-1 (W-OC-W), 918.12 cm-1 (W-Oe-W), 964.41 cm-1 (W=O), 1087.85 cm-1 (P-O), 3572.17 cm-1 (O-H), 1404.18 cm-1 (N-H) reinforced with wavenumber 1612.49 cm-1 with show vibration NH dari NH+, and to (NH4)6(β-P2W18O62)nH2O/SiO2 appears in wavenumbers 794.67 cm-1 (W-Oc-W), 918.12 cm-1 (W-Oe-W), 1049.28 cm-1 (W=O), 1087.85 cm-1 (P-O), 3564.15 cm-1 (O-H), 470.63 cm-1 (Si-O). Diffraction pattern of (NH4)6(β-P2W18O62)nH2O and (NH4)6(β-P2W18O62)nH2O/SiO2 compound show high crystanillity. The acidic properties showed (NH4)6(β-P2W18O62)nH2O/SiO2 more acidic than (NH4)6(β-P2W18O62)nH2O. Analysis of the effect of temperature on the stability of the compounds polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2 show that the temperature of 600ºC the shift in wavenumbers of the compounds caused by vibration W=O, W-OC-W, W-Oe-W has been lost. This shows that at a temperatures of 600ºC on heating can cause changes in the structure of polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2. Keywords : (NH4)6(β-P2W18O62).nH2O, Polyoxometalate, SiO2
Calcium oxide from Pomacea canaliculata and Babylonia spirata snails Triayu Septiani; Nurlisa Hidayati; Risfidian Mohadi
Science and Technology Indonesia Vol. 2 No. 3 (2017): 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 (444.253 KB) | DOI: 10.26554/sti.2017.2.3.68-70

Abstract

The preparation of CaO from golden snail (Pomacea canaliculata) and lion snail (Babylonia spirata) through decomposition at various temperature i.e 700o, 800o, 900o and 1000oC during 3 hours has been carried out. Calcium oxide from decomposition was characterized using X-Ray diffractometer. Furthermore, the characterization was continued using FT-IR spectrophotometer and determination of surface area using BET analysis. The results showed that the optimum temperature for preparation of CaO from golden snail and lion snail at 900oC with 2q values are: 32.2° , 37.4o , 54o , 64.2o , 67.3° and 32.4°, 37.5°, 67.5 °, respectively. FT-IR spectra showed characteristic vibrations for the Ca-O in the sample golden snail and lion snail combustion products at a temperature of 900oC. Ca-O absorption of golden snail samples in the wavenumber around 362.62 cm-1 and lion snail seen in wavenumber around 384.76 cm-1 indicating the presence of Ca-O vibration of the metal oxide of preparation. Golden snail and the lion snail combustion at 900oC temperature of each sample which has a surface area of 20.495 m2/g, while the lion snail 17.308 m2/g. The pore diameter of golden snail 3.753 nm and 11.319 nm of lion snail. All CaO can be categorized as mesoporous material. Keywords: golden snail, lion snail, decomposition, CaO
Preparation and characterization of calcium oxide from crab shells (Portunus pelagicus) and its application in biodiesel synthesis of waste cooking oil, palm and coconut oil Minaria Minaria; Risfidian Mohadi
Science and Technology Indonesia Vol. 1 No. 1 (2016): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (531.714 KB) | DOI: 10.26554/sti.2016.1.1.1-7

Abstract

Preparation of calcium oxide from Portunus pelagicus through thermal decomposition for 3 hours at various temperature 700°C, 800°C,900°C,1000°C, and 1100°C. The calcium oxidefrom decomposition was carried out and characterized by X-Ray Diffractometer (XRD), FT-IR spectrophotometer and SEM-EDX analyses. The result of XRD show decomposition Portunus pelagicus at 1000°C have diffraction pattern agree with the CaO diffraction standard with 2θ value 32.4º, 37.5º, 64.3º, and 67,5º. The FT-IR spectrum show vibration of CaO at wavenumber 354.9 cm-1. SEM-EDX data indicated the surface morphology calcium oxide of Portunus pelagicus more homogen than Portunus pelagicus before decomposition. The decomposition of CaO at 1000°C was applied in the syntesis of biodiesel from waste cooking oil, palm oil, and coconut oil. The biodiesel products have density 0.8621, 0.8725, and 0.8688 g/cm3. Viscosity are 5.27, 3.71, and 2.45 mm2/s(cst). Acid values respectively are 0.3069, 0.2423 and 0.2100 mg/KOH and Iodine numbers 39.48, 36.12 and 9.24 g I2/100g. All characteristic of biodiesel from waste cooking oil, palm oil, and coconut oil are agree with SNI standard. The best biodiesel product derived from coconut oil is agree to the parameter value of biodiesel standard. Keywords: biodiesel. Portunus pelagicus. calcium oxide. catalyst.
Impregnation of bentonite with cellulose as adsorbent of congo red Monica Theresa; Santa Oktavia Ginting
Science and Technology Indonesia Vol. 2 No. 2 (2017): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (708.06 KB) | DOI: 10.26554/sti.2017.2.2.37-44

Abstract

The process of bentonite impregnation with cellulose has been studied. Cellulose extracted from rubber wood and clay from natural bentonite was activated. The impregnation process is performed using thiourea as impregnant agent. The impregnation results were characterized by using FT-IR spectrophotometer then the material was used as congo red dye adsorbent. Factors affecting the adsorption process were studied by kinetic parameters and thermodynamic parameters. The FTIR results indicate the impregnation process was succesfully conducted the characterization by FTIR indicated resources of typical absorption of the hydroxyl (OH) and vibrational (-CH) vibration function groups as specific groups of cellulose Appearing at wave numbers 3464.15 cm-1 and 2368.59 cm-1 from impregnated material. Vibration Si-O-Si and Al-O-Si as bentonite-specific strands groups Appear at 1465.9 cm-1 and 609.51 cm-1 wavenumbers in the impregnated spectra. The adsorption thermodynamic study showed that the adsorption and adsorption capacity of the cellulose-impregnated bentonite adsorbent reached the optimum point at 50 ° C at 43.47 mol / g and energy of 11.62 kJ mol. The optimum enthalpy (ΔH) of cellulose bentonite was 143.13 kJ/mol and the minimum entropy (ΔS) at concentration of 40 mg/L was 0.207 kJ/mol. Keywords: Bentonite, cellulose, impregnation; adsorption; Congo red

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