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
 4   5   6   7   8 
A Review on Phase Change Materials Incorporation in Asphalt Pavement Intan Kumalasari; Madzlan Napiah; Muslich H. Sutanto
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12762

Abstract

Phase Change Material (later to be referred as PCM) has been successfully utilized in some areas. PCM has emerged as one of the materials for pavement temperature reducing due to its latent heat. Some research has been done regarding this topic. The objective of this paper is to review the development of PCM in asphalt pavement. The review has shown that organic PCM appears as the favourite PCM in asphalt concrete studies. Choice of porous material depends on method of incorporation. Reduction of temperature in PCM-asphalt mixture compared to conventional one is undoubtable. However, the mechanical performance of PCM-asphalt mixture need to be explored.
Bearing Failure Analysis on Gearbox Forced Draft Fan at LNG Plant Edward Rangga Pratama; Alaya Fadllu Hadi Mukhammad
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12756

Abstract

Boilers Forced Draft Fan has a gearbox reducer to reduce speed from steam turbine as a driver and fan as the driven. Based on Predictive Maintenance Group at Machinery and Heavy Equipment Section, it was found that gearbox has high vibration and noise when boilers load on 195 Ton/Hr (Max Load 295 Ton/hr). Vibration Analysis indicates that the source of vibration comes from bearings with peak value 0.572 in/sec at gearbox high speed outboard vertical and 0.593 in/sec at gearbox high speed outboard horizontal (Max Allowance 0.50 in/sec). Lubrication analysis using X-ray Flourescence method, to see wear particle on lubricating oil showed that Tin(Sn) content is very high 203.62 mg/L (maximum allowance for Tin(Sn) at gearbox is 20mg/L), but wear debris are not found in lubricating oil. Gearbox disassembly found that high speed and low speed bearings suffered severe corrosion. Corrosion at bearings are caused by water contamination on lubrication oil, it comes from steam leak due to carbon ring failure at steam turbine which is steam turbine bearing lubrication and gearbox lubrication get into one lubrication system. After Bearings replaced with a new one, vibration analysis shown improved vibration conditions 0.084 in/sec at gearbox high speed outboard vertical and 0.066 in/sec at gearbox high speed outboard horizontal. In conclucion, high vibration and noise at gearbox reducer were caused by bearings failure due to severe corrosion, and water contamination on lubrication oil for gearbox  due to carbon ring failure on steam turbine.
Working Volume and Milling Time on the Product Size/Morphology, Product Yield, and Electricity Consumption in the Ball-Milling Process of Organic Material Asep Bayu Dani Nandiyanto; Riezqa Andika; Muhammad Aziz; Lala Septem Riza
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12752

Abstract

Analysis of ball-milling process under various conditions (i.e. working volume, milling time, and material load) on the material properties (i.e. chemical composition, as well as particle size and morphology), product yield, and electricity consumption was investigated. Turmeric (curcuma longa) was used as a model of size-reduced organic material due to its thermally and chemically stability, and fragile. Thus, clear examination on the size-reduction phenomenon during the milling process can be done without considering any reaction as well as time-consuming process. Results showed that working volume is prospective to control the characteristics of product. Working volume manages the shear stress and the collision phenomena during the process. Specifically, the lower working volume led to the production of particles with blunt-edged morphology and sizes of several micrometers. Although working volume is potentially used for managing the final particle size, this parameter has a direct impact to the product yield and electricity consumption. Adjustment of the milling time is also important due to its relation to breaking material and electrical consumption.
Limitation in Fabricating PSf/ZIF-8 Hollow Fiber Membrane for CO2/CH4 Separation Nik Abdul Hadi Md Nordin; Ahmad Fauzi Ismail; Surya Murali Racha; Ng Be Cheer; Muhammad Roil Bilad; Zulfan Adi Putra; Mohd Dzul Hakim Wirzal
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12757

Abstract

Hollow fiber membrane configuration is way forward in membrane development since it possesses higher packing density and effective surface area per unit module compared to other configuration. Since majority of mixed matrix membrane (MMM) for gas separation reported focuses on flat sheet membrane development, this report aims to address the challenges faced in fabricating hollow fiber MMM. In this study, hollow fiber formulation is fabricated and their MMM using different types of fillers (virgin and modified ZIF-8) are prepared and used as a dispersed phase. The neat hollow fiber membrane shows good results with CO2 permeance of 104.39 GPU and CO2/CH4 selectivity of 29.28, in comparison with reported literature. Upon filler incorporation, the resulted MMMs appear to be diminished in both CO2 permeance and CO2/CH4 selectivity. While using modified ZIF-8, lesser deterioration was shown compared to pure ZIF-8, this phenomenon is likely to occur due to the changes in solution stability which causes notable changes in membrane morphology and performances.
Numerical Simulation of Natural Convection in the Air Gap of a Vertical Flat Plat Thermal Solar Collector with Partitions Attached to Its Glazing Adel Laaraba; Abderrahmane Khechekhouche
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: VOLUME 3, ISSUE 2, September 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12753

Abstract

Heat transfer in the air gap of a vertical flat plat thermal solar collector containing partitions attached to its glazing has been studied numerically. The absorber and the glazing are kept at constant and different temperatures, while the vertical walls (insulation) were kept adiabatically. A conjugate formulation was used for mathematical formulation of the problem and a computer program based on the control volume approach and the simpler algorithm was used. The main aim of the current paper is to study numerically the effects of number of fins and their length on the air pattern and heat transfer. Experimental results showed that interesting phenomena happened, especially in the heat transfer process. It was observed that the heat transfer rate through the air gap is affected greatly and can be controlled by the number of attached fins to the glazing of the solar collector as well as the fin lengths, and the addition of partitions reduces the heat losses by convection by  60%. This study will brings good advantages for further uses, especially related to the heat transfer phenomena in the solar applications.
Utilization & Quality of Information System for Administration Services Based on ICT In Patehan, Kraton, Yogyakarta Rohmah, Amandita 'Ainur; Rachmawati, Rini
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.12680

Abstract

Development of technology and application of e-government at city, sub-district, and village become the factor of emergence of Information and Communication Technology-based information service system innovation. Yogyakarta has implemented e-government as one of the strategies used to achieve the slogan of Yogyakarta Smart City. One of the areas that have implemented the concept is Patehan, Kraton, Yogyakarta. This research aims to describe the system of online administrative services, identify of utilization by the community, and measure the quality of its services. The research method used was qualitative and quantitative methods. Data collected are primary data and secondary data with analytical technique used is descriptive qualitative and quantitative. Based on the results of the research can be seen that the administrative service system in Patehan (SiWarga Patehan) is a system made by citizens, for citizens, and from citizens to take care of online certificate from RT, RW until the village that serve as one alternative for the community has high mobility. Based on 60 respondents, it can be concluded that the administrative system of SiWarga Patehan included into the category of good with the service index of 79.97.
Identifying the Factor that Promotes Vertical Partner-ships: Empirical Evidence from Tier-1 and Tier-2 Compa-nies in Jabodetabek-Indonesia Syah, Donny Oktavian
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.14427

Abstract

Indonesian automotive sector played an important role to Indonesian GDPs; it contributes 28% in manufacturing composition. The goal of this research is to examine the vertical partnership between tier-1 and tier-2 automotive component companies in Jabodetabek, Indonesia, as concerns technology transfer, technical exchange, government role, and supplier performance. 93 companies, consisting of 59 tier-1 companies and 34 tier-2 companies became respondents in this study. The research was conducted by visiting sites and interviewing companies, based on Likert-scale questionnaires. Interviewees were persons at the middle management level or higher who understood or were responsible for measuring product quality (purposive sampling). The results of questionnaires were proceeded and analyzed by Structural Equation Model Partial Least Square (SEM-PLS) path modeling using smart-PLS 3.2.7 software. The results showed that there is a significant relationship between the government’s role and technology transfer, as well as between technology transfer and supplier performance improvement. However, there was no significant relationship between government role and supplier performance improvement, nor between technical exchange and supplier performance improvement.
Experimental Investigation on Mechanical Joint of Lontar (Borassus Flabellifer) Fiber Reinforced Polyester Composites under Static Flexural Test Bale, Jefri S; Pell, Yeremias M; Jafri, Muhamad; Selan, Rima
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.15239

Abstract

This study has been conducted to investigate the flexural strength of Borassus Flabellifer Fiber/BFF reinforced polyester composite joint under static condition. Tests were carried out to study the flexural strength of double strap butt joint and single lap joint of BFF polyester composite. In addition, post observation of macroscope was used to map failure behavior. The results shown that the flexural strength of single lap joint is higher compared to double strap butt joint of  BFF polyester composite. The larger cross-sectional area and the existence of gap area could be the main reason for lower flexural strength generated by double strap butt joint of  BFF polyester composite. The failure of BFF polyester composite joints under flexural test indicated the brittle failure behaviour that fiber breakage was found to be the final failure mechanism which start with matrix cracking and fiber-matrix debonding failure mechanisms.
Process Simulation on Fast Pyrolysis of Palm Kernel Shell for Production of Fuel Nayaggy, Mangala; Putra, Zulfan Adi
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.15803

Abstract

As the worlds primary source of energy is depleting, an alternative particularly renewable energy is being explored. This work is a preliminary study on fast pyrolysis process of palm kernel shell to produce liquid fuel. The simulation uses pyrolysis data obtained from one of the previous works on fast pyrolysis of palm kernel shell. As there are no literature available on upgrading of bio oil from fast pyrolysis of palm kernel shell, the chemical reactions are synthesised based on upgrading of bio oil from different biomass. The upgraded oil is then analysed by comparing its distillate curve with that of the ASTM of gasoline. The distillation curves are shown to be quite similar as the components found in the oil almost resemble those in the gasoline. Thus, the bio oil from fast pyrolysis of palm kernel shell has almost similar components compared to the ASTM of gasoline.
Isolation and Identification of Hydrocarbon Degradation Bacteria and Phosphate Solubilizing Bacteria in Oil Contaminated Soil in Bojonegoro, East Java, Indonesia Rahayu, Yuni Sri
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.14923

Abstract

Petroleum is a mixture of hydrocarbon complexes with organic compounds from sulfur, oxygen, nitrogen and metal-containing compounds. These organic compounds can be used as substrate for bacterial growth. This study aimed to isolate and identify hydrocarbon degrading bacteria and phosphate solubilizing bacteria in oil-contaminated soil in Bojonegoro. This study used an exploration method to find each of the two types of hydrocarbon degrading bacteria and phosphate solubilizing bacteria from soil samples in Bojonegoro that contaminated by oil. Identification of isolates bacterial included macroscopic observations of bacteria, gram staining on bacterial cells and physiological tests. Macroscopic observations include the form of colonies, colony diameter, colony color, colony edge, and elevation. The physiological test using Microbact Identification System to determine the physiological characteristics of bacteria so that genera and types of bacteria can be known. The identification of organisms was based on changes in pH and use of the substrate. The results of data analysis were obtained from five types of bacteria from soil samples that contaminated by oil which were successfully isolated. After identification of species was done, four species of bacteria were obtained, namely Pseudomonas pseudomallei, Pseudomonas fluorescens-25, Flavobacterium odoratum, and Enterococcus sp.

Page 6 of 22 | Total Record : 220

 4   5   6   7   8 

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