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Makara Journal of Technology
Published by Universitas Indonesia
ISSN : 23552786     EISSN : 23564539     DOI : https://doi.org/10.7454/mjt
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Engineering Materials Science & Nanotechnology Mechanical Engineering
MAKARA Journal of Technology is a peer-reviewed multidisciplinary journal committed to the advancement of scholarly knowledge and research findings of the several branches of Engineering and Technology. The Journal publishes new results, original articles, reviews, and research notes whose content and approach are of interest to a wide range of scholars. It also offers rapid dissemination. MAKARA Journal of Technology covers the recent research in several branches of engineering and technology include Electrical & Electronics Engineering, Computer Engineering, Mechanical Engineering, Chemical & Bioprocess Engineering, Material & Metallurgical Engineering, Industrial Engineering, Civil & Architecture Engineering, and Marine Engineering. Criteria used in determining acceptability of contributions include newsworthiness to a substantial part of the engineering & technology and the effect of rapid publication on the research of others. This journal, published three times each year, is where readers look for the advancement of discoveries in engineering and technology.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 485 Documents
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Sorption-based Energy Storage Systems: A Review Thu, Kyaw; Nasruddin, Nasruddin; Mitra, Sourav; Saha, Bidyut Baran
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

Mismatched timing between the supply and demand of energy calls for reliable storage systems. Energy storage systems have become further significant with the widespread implementation of renewable energy. These systems can mitigate problems that are often associated with renewable energy sources such as supply unreliability while meeting the de-mand during peak hours. Energy can be stored in various forms, yet storage systems can be generally grouped based on their output forms, namely (i) electricity and (ii) heat or thermal energy. Electrical energy is the most convenient and effective form since it can power almost all modern devices. However, the electricity itself is vastly produced by ther-modynamic cycles at a particular thermal efficiency using thermal energy from fossil fuels. Meanwhile, thermal energy for the HVAC&R and the production of hot water remains the largest portion of the building energy sector. Thermal energy can be stored in the form of sensible, latent, and thermochemical energy. This review focuses on thermochemi-cal sorption-based energy storage systems. These systems exploit endothermic and exothermic sorption processes for charging and discharging of the thermal energy. Sorption-based storage systems exhibit huge potential due to a high energy density and their ability to store the energy at room temperature. We discuss the current state-of-the-art develop-ments, key challenges, and future prospects of sorption-based energy systems.
Electrical Properties of A Novel Solid Biopolymer Electrolyte based on Algi-nate Incorporated with Citric Acid Ahmad Fuzlin, Ahmad Faizrin; Ismail, Noor Syahida; Nagao, Yuki; Samsudin, Ahmad Salihin
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

In the present study, a novel solid biopolymer electrolyte (SBE) system is introduced by doping citric acid into alginate polymer. A sample of the alginate-citric acid SBE system was prepared via a solution casting technique. Using electrical impedance spectroscopy (EIS), the electrolytes of alginate-citric acid analyzed from 5 Hz to 1 MHz achieved the highest conductivity at 20 wt.% of 5.49 × 10-7 S cm-1. The temperature dependence of various citric acid amounts obeyed the Arrhenius rule with R2~1, where all SBE systems were thermally activated with increasing temperature. The dielectric studies of the alginate-citric acid SBE system showed non-Debye behavior based on data measured using complex permittivity (ε*) and complex electrical modulus (M*) at selected temperature, where no single relation was found in the new biopolymer electrolyte system.
Molecularly Conductive Behavior of Blended Polymer Electrolyte-based CMC/PVA Mohd Ali, Noor Saadiah; Zhang, Dishen; Nagao, Yuki; Samsudin, Ahmad Salihin
Makara Journal of Technology Vol. 23, No. 1
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Abstract

This study investigated the electrical conduction and structural behavior of blended polymer electrolyte (BPE)-based carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) in the development of solid-state electrochemical devices. Based on impedance spectroscopy and correlating Fourier transform infrared (FTIR) with thermogravimetric analysis, a framework was proposed to explain the structural enhancement of the BPE system. As revealed by FTIR, the optimum conductivity of CMC/PVA BPEs was 9.21 × 10−6 Scm−1 for 80:20 composition attributed to the intermolecular attraction between the polymers. Thermal stability of the CMC/PVA was influenced by the formation of a hydrogen bond between the hydroxyl (-OH), carboxylate (-COO-), and ether linkage (-COC-) functional groups. The finding provides insights into blended polymer electrolyte-based CMC/PVA, which is beneficial in designing safe, thin, and lightweight energy storage devices.
Data Fusion Method Based on Adaptive Kalman Filtering Sirenden, Bernadus Herdi
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

This paper discusses data fusion methods to combine the data from a rotary encoder and ultrasonic sensor. Both sensors are used in a micro-flow calibration system developed by the Research Center of Metrology LIPI. The methods studied are hierarchical data fusion and Kalman filtering. Three types of Kalman filters (KFs) are compared: the conventional Kalman filter and two adaptive Kalman filters. Moreover, a method to combine the uncertainty results from KF in hierarchical data fusion is proposed. The aim of this study is to find appropriate methods of data fusion that can be implemented in micro-flow calibration systems. Data from two experiment setups are used to compare the methods. The result indicates that one of the methods (with little adjustment) is more appropriate than the other.
Multistage Sonication Effect on the Composition and Properties of Degraded Chitosan Product Arifin, Nurul Laili; Savitri, Emma; Indah, Anjar; Putra, Fesa; Sumarno, Sumarno
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

The sonication method randomly breaks polymer chains to produce a varied distribution of products. A scheme with multi-stage sonication steps is proposed to identify oligomers and low molecular weight chitosan based on changes to the degrad-ed product. For each sonication level, 1% (w/v) chitosan in 1% (v/v) aqueous acetic acid was sonicated for 120 min at 60 °C. The products of the sonication treatment were deprotonized by adding an alkali solution, freeze dried and insoluble product re-sonicated until a low molecular weight was produced. Low molecular weight chitosan/insoluble products were character-ized with Fourier-transform infrared spectra (FT-IR) and X-ray diffraction (XRD) to determine the effect of multistage soni-cation on degree of deacetylation (DD) and degree of crystallinity. The viscosity of the average molecular weight of insolu-ble chitosan was estimated by a viscometric method, while the degree of polymerization (DP) of the chitosan oligomers (COS) were determined by end group analysis. The results showed that the molecular weight of insoluble chitosan decreased and reached a limiting value, (Mlim). The percent yield of oligoglucosamine of the soluble products increased with the num-ber of the sonication stages. The degree of crystallinity of insoluble chitosan increased from 19% to 34.14% while the DD decreased from 82% to 78.1%.
Adsorption of Heavy Metal Ions by Oil Palm Decanter Cake Activated Carbon Yusoff, Mohd. Ezreeza Mohamed; Idris, Juferi; Zainal, Nahrul Hayawin; Ibrahim, Mohamad Faizal; Abd-Aziz, Suraini
Makara Journal of Technology Vol. 23, No. 2
Publisher : UI Scholars Hub

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Abstract

Adsorption processes are widely used for the removal of heavy metals from waste streams. Oil palm decanter cake (OPDC) is used as a bioadsorbent because of its compositional properties for activated carbon production; moreover, it is a readily available raw material produced in palm oil mills and is thus abundant and cheap. In this study, the OPDC was carbonized at 700 °C and activated using steam at 700 °C to produce oil palm decanter cake activated carbon (AC-OPDC). Batch adsorption experiments were carried out to compare the adsorption capacities of the raw OPDC and the AC-OPDC for heavy metals removal. The maximum adsorption capacities of AC-OPDC on Cu(II), Pb(II), and Zn(II) were found to be 45.01, 128.51, and 39.21 mg/g, respectively, which were higher than those of the raw OPDC. This study demonstrates that the AC-OPDC has the potential to be a bioadsorbent for heavy metal removal from wastewater.
A Study of the Electron Regeneration Efficiency of Solar Cells Fabricated Using CMC/PVA-, Alginate-, and Xanthan-based Electrolytes Shaafi, Nur Farha; Muzakir, Saifful Kamaluddin; Sahraoui, Bouchta
Makara Journal of Technology Vol. 23, No. 2
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Abstract

A photovoltaic (PV) mechanism consists of three important steps, i.e., (i) electron excitation upon absorption of photon with energy higher than the bandgap of fluorophore, (ii) excited-state electron injection from the fluorophore to the pho-toelectrode, and (iii) electron regeneration from the electrolyte to the fluorophore. An efficient electron regeneration could be achieved upon fulfillment of the requirements of energy alignment, i.e., lowest unoccupied molecular orbital of fluorophore (LUMOfluorophore) > redox potential of electrolyte > highest occupied molecular orbital of fluorophore (HOMOfluorophore). This study investigated the electron regeneration efficiency of excitonic solar cells fabricated using three polymer-based electrolytes, i.e., (i) 60% carboxymethyl cellulose (CMC) blended with 40% polyvinyl alcohol (PVA), (ii) alginate, and (iii) xanthan. The redox potentials of the electrolytes (Eo) were calculated using quantum chemical calculations under the framework of density functional theory. The compatibility of fluorophore and electro-lyte was analyzed in terms of the energy level alignment. The cells fabricated using the three polymer-based electrolytes were analyzed, with the CMC/PVA-based cell yielding the highest efficiency, η, of 1.39% under the illumination of the sun. The low η of the cells can be attributed to the incompatible Eo of the electrolytes, which exhibited a higher energy level than the LUMOfluorophore. The alginate- and xanthan-based cells exhibited inferior PV properties (i.e., open circuit voltage, short circuit current, fill factor, and η) to that of the CMC/PVA-based cell. This finding can be attributed to the increment of energy offset between Eo and HOMOfluorophore.
Study of Ecological Design of Residential Complexes Using SPSS to Elevate Resident Satisfaction Kolbadinejad, Soheil Malekpour; Ravasjan, V. Malekpour; Darvish, A.
Makara Journal of Technology Vol. 23, No. 2
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Abstract

This article reports the general residential satisfaction, affecting ecological factors, and their importance in area in Tehran. The collected field data was analyzed using SPSS. Cronbach's alpha variable was used to determine the reliability of the questionnaire and the Friedman test was used to assess priorities that influence residential satisfaction. The results show that the quality of residential environments and general satisfaction of their residents may be enhanced by identifying these criteria and making appropriate plans for their improvement.
Use of the “DNAChecker” Algorithm for Improving Bioinformatics Research Bhat, Nausheen; Wijaya, Ezra Bernadus; Parikesit, Arli Aditya
Makara Journal of Technology Vol. 23, No. 2
Publisher : UI Scholars Hub

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Abstract

Basic Local Alignment Sequencing Tool (BLAST) is a bioinformatics tool used for analyzing nucleotide sequences with regards to their similarity. BLAST can be found online on biological databases such as the National Center for Biotechnology Information (NCBI) and other such repositories. The mechanism of BLAST allows the target sequence to be compared with other sequences to find regions of local similarity, and thus, a comparability quotient that determines the resemblance between the sequences is created. Due to the open-platform nature of the online databanks, several sequences can be accepted with little to no interjections regarding the quality of sequence submitted. An example of unclean nucleotide sequences can be based on the number of non-template nucleotides, denoted as “N,” present within the sequence. Here we develop a self-established nucleotide sequence reading program known as “DNAChecker,” which helps identify the quality of the target sequence and therefore proposes the effectiveness of the BLAST result. DNAChecker is an inbuilt, program that runs on Python 3.4 and was implemented in the United States Agency for International Development (USAID) project conducted in Indonesia International Institute for Life Sciences. Although DNAChecker has proven to be useful, it has a lot of room for improvements, such as having a more objectively accurate means of differentiating between good and bad sequences.
Component Analysis and Antiangiogenic Activity of Thailand Stingless Bee Propolis Ishizu, Eriko; Honda, Sari; Ohta, Tosihro; Vongsak, Boonyadist; Kumazawa, Shigenori
Makara Journal of Technology Vol. 23, No. 2
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Abstract

Propolis is a natural resin produced by honey bees from certain plants, has gained popularity as a food and alternative medicine. However, to the best of our knowledge, few studies on native Thailand stingless bee propolis are available. Information on the chemical composition and biological activities of propolis is needed to investigate its potential utility. Recently we have reported the possible plant origin of Thailand stingless bee propolis, Garcinia mangostana. In this study, further component analysis, functional evaluation, and identification of the plant origin of Thailand stingless bee propolis are conducted. Nine xanthones, including α-mangostin, garcinone C, γ-mangostin, cochinchinone T, β- mangostin, gartanin, 8-deoxygartanin, 9-hydroxycalabaxanthone, and mangostanol, were identified from the propolis. Comparative analysis of 70% ethanol extracts of Thailand stingless bee propolis (EEP) and the yellow resin from the fruit surface of G. mangostana (EEM) was performed using LC-MS, and similar chromatographic patterns were obtained. This result suggests that the plant origin of Thailand stingless bee propolis is confirmed to be the yellow resin from the fruit surface of G. mangostana. EEP and EEM were then tested for their ability to inhibit the tube formation of human umbilical vein endothelial cells, and both samples inhibited the tube formation of these cells in a concentrationdependent manner. This result indicates that Thailand stingless bee propolis may have future applications in the prevention and treatment of angiogenesis-related diseases.

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