cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota bandung,
Jawa barat
INDONESIA
Indonesian Journal of Science and Technology
Published by Universitas Pendidikan Indonesia
ISSN : 25278045     EISSN : 25281410     DOI : -
Core Subject : Science, Social,
Computer Science & IT Environmental Science
Arjuna Subject : -
Articles 220 Documents
 11   12   13   14   15 
Alkaloids Production and Cell Growth of Cinchona ledgeriana Moens: Effects of Fungal Filtrate and Methyl Jasmonate Elicitors Yustiny Andaliza Hasibuan; Diah Ratnadewi; Zainal Alim Mas’ud
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.31479

Abstract

Cinchona alkaloids are known as antimalaria and anti-arrhythmic. Due to the long waiting time to harvest, cell culture technology is a challenge. This study aimed to determine the effects of elicitors, filtrate of two strains of endophytic fungi and methyl jasmonate (MeJA), in cell suspension culture of Cinchona ledgeriana on quinine and quinidine production. The cells were cultured for seven weeks in woody plant (WP) media treated with either of those elicitors in various concentrations. The cells growth was observed and the alkaloids were analyzed by HPLC. Cells treated with MeJA failed to grow that led to the cell biomass insufficiency for alkaloids determination.  It indicates that the cells are quite sensitive to even low concentration of MeJA that hampered the growth. Cells treated with the filtrate of Diaporthe sp. M13-Millipore filtered (S2M) gave the least cell biomass but presented the highest content of both alkaloids. Diaporthe sp. strain M-13 is stronger as elicitor than M-23 for this plant species. Filtrate of non-virulent fungi can elevate the biosynthesis of alkaloids. This reconfirms that cultured cells are capable to produce secondary metabolites and the productivity can be increased by using an appropriate elicitor.  
Artificial Neural Network Analysis of Sulfide Production in A Moroccan Sewerage Network Asmae El Brahmi; Souad Abderafi; Rachid Ellaia
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.32322

Abstract

Sulfide in urban wastewater leads to the formation ofhydrogen sulfide and its release in the air. This molecule is anodorous compound, representing an annoyance and healththreat for workers and the nearby population. In order toprevent hydrogen sulfide emission, it is necessary toevaluate sulfide concentration in sewage water and identifyenvironmental key parameters that enhance sulfideproduction. In this study, Artificial Neural Network (ANN)method was used to analyze the presence of this substancein a Moroccan sewerage network. Experimental data ofwastewater composition of Tangier sites (north of Morocco)were used for the training, testing, and validating the ANNmodel. The results showed satisfactory capability of ANN topredict sulfide concentration in aqueous phase, reachingvalue of 89%. Dissolved oxygen and temperature have themost significant impact on sulfide production. The obtainedmodel can be the first step towards monitoring sulfide forbuilding up in sewers and consequently applying it into anappropriate treatment.
Association of Interest, Attitude and Learning Habit in Mathematics Learning Towards Enhancing Students’ Achievement Suhaizal Hashim; Alias Masek; Bismi Nurnazatul Shima Mohd Mahthir; Ana Haziqah A Rashid; Danakorn Nincarean
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.31526

Abstract

Mathematics is fundamentally important for Science and Technology, as well as in engineering. Mathematics is compulsory for students since all engineering subjects were Mathematically oriented. However, the preliminary study found that students’ achievement in Mathematics courses have been associated with three main factors, namely interest, attitude and learning habit, as in the KASH Model (Knowledge, Attitude, Skills and Habits). This Model stipulated that poor performance is not just lacking in knowledge and skills but also including poor attitude and habits. Therefore, this study aims to investigate the students’ level and relationship between interest, attitude and learning habit based on KASH Model. A total of 58 students were selected as a sample of the study, who enrolled in the Thermodynamics, Fluid Mechanics and Solid Mechanics subjects. A set of questionnaires with 21 items was used to collect data; a descriptively analysis was used to find the mean and percentage, as well as correlation index using Pearson. The results; high level of factor of interest, attitude and learning habit, and high correlation between interest, attitude and habit. The implication is that teaching and learning process must equally fostering all these variables to achieve a high level of students’ achievement, especially in Mathematics subjects.
Relationship between Shear Velocities Recorded by Microtremor Observations and Seismic Cone Penetration Test Results Rusnardi Rahmat Putra; J. Kiyono; Sai K. Vanapalli; Y. Ono
Indonesian Journal of Science and Technology Vol 6, No 2 (2021): IJOST: VOLUME 6, ISSUE 2, September 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i2.34191

Abstract

This research proposes a relationship between two methods such as a numerical approach by conducting a microtremor array observation and field survey by using the seismic cone penetration test unit (SCPTu). A database of shear-wave velocity (Vs) measurements was established using the microtremor array technique and seismic cone penetration test unit (SCPTu) on high-quality samples of rock and soft soil in Padang city, Indonesia. The study also demonstrates that the Vs values obtained from the different methods are consistent with the microtremor array technique. This technique may thus be deemed a valuable tool, as it can be used in engineering practice with confidence. Comparison of the Vs for different soils at the first layer between the microtremor array observation results and the SCPTu results exhibited the microtremor array method is unable to determine the Vs  at the layer where its Vs changes dramatically, such as at the same layer as station UNP at 2 to 3.5m deep.
Toxic heavy metals removal using a hydroxyapatite and hydroxyethyl cellulose modified with a new Gum Arabic A Errich; K Azzaoui; E Mejdoubi; B Hammouti; N Abidi; N Akartasse; L Benidire; S EL Hajjaji; R Sabbahi; A Lamhamdi
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.31480

Abstract

The objective of this work was to develop a process that allows the synthesis of an apatitic material of controlled composition and morphology, which could be used for medical and environmental applications. The adsorbent was synthesized, and characterized using scanning electron microscopy, nuclear magnetic resonance, Thermal analysis and other techniques, Atomic Force Microscopy, X-ray photoelectron spectroscopy and Total organic carbon. Different experimental parameters such as the effect of the amount of adsorbent, solution pH and temperatures and contact times were studied. Pseudo-order kinetics models were studied, and our data followed a pseudo second order. Experimental data were analyzed for both Langmuir and Freundlich models and the data fitted well with the Langmuir isotherm model. To understand the mechanism of adsorption, thermodynamic parameters like standard enthalpy, standard Gibbs free energy, and standard entropy were studied. The study indicated that the process is spontaneous, exothermic in nature and follow physisorption mechanisms. The novelty of this study showed surface of composite based of hydroxyapatite has the ability to highlight the surface designed for efficient removal of Cu2+ and Zn2+ ions, from aqueous solutions more than other studies.
How to Calculate Adsorption Isotherms of Particles Using Two-Parameter Monolayer Adsorption Models and Equations Risti Ragadhita; Asep Bayu Dani Nandiyanto
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.32354

Abstract

Adsorption isotherm is the most important calculation to predict and analyze the various possible mechanisms that occur in adsorption process. However, until now, most studies only presented the adsorption isotherm theory, and there are no studies that explain the adsorption isotherm thoroughly and in detail from theory to calculation. Therefore, this study contains guidelines for selecting the type of adsorption isotherm to describe the entire adsorption data set, which is featured by the ten most common adsorption isotherms. The steps of how to analyze the two-parameter monolayer adsorption are presented. This study is expected to provide clear and useful information for researchers who are working and studying on the adsorption process.
Stealth Detection System via Multistage Radar and Quantum Radar Kulshreshtha, Abhijit; Al-Obaidi, Abdulkareem Sh. Mahdi
Indonesian Journal of Science and Technology Vol 5, No 3 (2020): IJOST: VOLUME 5, ISSUE 3, 2020
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v5i3.26806

Abstract

In today’s era of advanced weapons and technology development, many remarkable inventions have shifted the balance of war towards the strategically enhanced military equipped with tactical weapons and armaments. One of these strategic advancements is stealth technology due to which stealth aircraft are high in demand for the military. The question that rises is How to detect a stealth object? This paper proposes a novel anti-stealth technique using void detection, high frequency wave interference and neutrino beam propagation. Void detection method uses a modified satellite-based radar that searches for areas in the aerospace from which the transmitted signals sent to the ground receiving station are blocked or deflected. High frequency wave interference method is used to generate a stellar trajectory of the stealth aircraft at the detected void. Neutrino beam comprises of energy quanta mainly neutrinos, which are able to surpass the absorption or deflection systems in the stealth body of aircraft. This unique phenomenon produces a moving image, which is the precise location of the aircraft in the space. Using these methods, the trajectory of the aircraft is detected which ultimately leads to the detection of the stealth aircraft itself. The newly proposed methods which are theoretically more reliable than the existing methods may not have been tested but the method planning make them practically feasible considering that the technology used is a part of advanced engineering today.  
Deburring Method of Aluminum Mould Produced by Milling Process for Microfluidic Device Fabrication Kushendarsyah Saptaji; Farid Triawan; Tong Keong Sai; Asmelash Gebremariam
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.31852

Abstract

The existence of top burrs in micro-scale features produced by milling process can deteriorate the surface quality of a product. Ductile metals, such as aluminum alloys, are prone to suffer from top burrs formation after a slot-milling process. A brief review on the state-of-the-art of burr removal process in micro-scale milling is provided in this paper. Various deburring methods were reportedly able to remove the burrs in micro-scale features, however a much simpler method is still needed. In the present work, a deburring process by stainless steel end brushing is introduced for aluminum mould used in microfluidic device fabrication. The micro-scale features are produced by slot-milling process followed by the deburring process. The deburred moulds are then visually observed using optical microscope and Scanning Electron Microscope (SEM) and the average surface roughness and its features profile are measured using 3D Laser Scanning Confocal Microscope. As a result, the proposed deburring method can successfully remove the top burrs, as indicated by a height reduction of about 21% due to the removal action by the brush. Hence, a burr-free embossing mould with complex shape channel features can be produced by milling and by applying a simple deburring process using stainless steel end brush.
Bacterial Cell Inactivation Using a Single-Frequency Batch-Type Ultrasound Device Poetro Sambegoro; Maya Fitriyanti; Bentang Arief Budiman; Kamarisima Kamarisima; Sekar Wangi Arraudah Baliwangi; Calvin Alverian; Saeed Bagherzadeh; Ganesan Narsimhan; Pingkan Aditiawati; Ignatius Pulung Nurprasetio
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.31516

Abstract

Ultrasound technology employs cavitation to generate high-pressure soundwaves to disrupt bacterial cells. This study reveals the effectiveness of a single frequency ultrasound device for bacterial cell inactivation. A low-cost ultrasound device having a single frequency, i.e. 22 kHz for lab-scale application, was developed first, and the prototype was mechanically designed and analyzed using the finite-element method to assure the targeted natural frequency could be achieved. The prototype was then tested inactivating bacterial cells, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), in a simple medium and a food system, and the results were then compared to a commercial system. A treatment time of up to 15 minutes was able to reduce E. coli and B. subtilis cells by 3.3 log and 2.8 log, respectively, and these results were similar to those of the commercial system. The effectiveness of bacterial cell inactivation using the developed single-frequency ultrasound device is then discussed. The findings are useful for designing low-cost ultrasound devices for application in the food industry.
Carbon-coated Single-phase Ti4O7 Nanoparticles as Electrocatalyst Support Christina Wahyu Kartikowati; Aditya Farhan Arif; Osi Arutanti; Takashi Ogi
Indonesian Journal of Science and Technology Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v6i1.32519

Abstract

The unique structure of Magnéli phases TiOx renders them effective for the electrochemical applications. This work demonstrates a synthesis of carbon-coated Magnéli phases TiOx (TiOx@C) nanoparticles from 3-aminophenol and rutile titania (TiO2) nanoparticles as a support for platinum (Pt) electrocatalyst. 3-aminophenol was polymerized and carbonized on the surface of TiO2 nanoparticles respectively in a microwave hydrothermal reactor and a tubular furnace. Reduction of the carbon-coated TiO2 (TiO2@C) into TiOx@C was performed in hydrogen atmosphere at 800-1050 °C. The carbon coating effectively prevented TiO2 nanoparticles from sintering, resulted in TiOx@C sizes from 50 to 100 nm. Single-phase Ti4O7 core, which has the highest theoretical electrical conductivity among the Magnéli phases, was obtained from reduction of TiO2@C at 1000 °C. for 10 min C/Ti4O7-supported Pt exhibited an electrochemical surface area of 46 m2 mgPt-1 at 15% Pt loading, slightly higher than that reported for commercial TKK electrocatalyst with 20% Pt loading (44.13 m2 mgPt-1).

Page 13 of 22 | Total Record : 220

 11   12   13   14   15 

Filter by Year

2016 2025


Reset
Filter By Issues
All Issue Vol 10, No 1 (2025): (ONLINE FIRST) IJOST: April 2025 Vol 10, No 1 (2025): IJOST: April 2025 Vol 9, No 3 (2024): IJOST: December 2024 Vol 8, No 3 (2023): (ONLINE FIRST) IJOST: December 2023 Vol 8, No 2 (2023): (ONLINE FIRST) IJOST: September 2023 Vol 8, No 1 (2023): IJOST: April 2023 Vol 7, No 3 (2022): IJOST: VOLUME 7, ISSUE 3, December 2022 Vol 7, No 2 (2022): IJOST: VOLUME 7, ISSUE 2, September 2022 Vol 7, No 1 (2022): IJOST: VOLUME 7, ISSUE 1, April 2022 Vol 7, No 3 (2022): IJOST: December 2022 Vol 6, No 3 (2021): IJOST: VOLUME 6, ISSUE 3, December 2021 Vol 6, No 2 (2021): IJOST: VOLUME 6, ISSUE 2, September 2021 Vol 6, No 1 (2021): IJOST: VOLUME 6, ISSUE 1, April 2021 Vol 5, No 3 (2020): IJOST: VOLUME 5, ISSUE 3, 2020 Vol 5, No 2 (2020): IJOST: VOLUME 5, ISSUE 2, 2020 Vol 5, No 1 (2020): IJOST: VOLUME 5, ISSUE 1, 2020 Vol 5, No 1 (2020): IJOST: April 2020 Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019 Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019 Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018 Vol 3, No 1 (2018): IJoST: VOLUME 3, ISSUE 1, April 2018 Vol 2, No 2 (2017): IJoST: VOLUME 2, ISSUE 2, September 2017 Vol 2, No 1 (2017): IJoST: VOLUME 2, ISSUE 1, April 2017 Vol 1, No 2 (2016): IJoST: VOLUME 1, ISSUE 2, September 2016 Vol 1, No 1 (2016): IJoST: Volume 1, Issue 1, 2016 Vol 1, No 1 (2016): IJoST: VOLUME 1, ISSUE 1, April 2016 More Issue