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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 7 Documents
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Search results for , issue "Vol. 23, No. 1" : 7 Documents clear
Wavelet Transform on Digital Rainbow Hologram based on Spectral Compression for Quality Enhancement in 3D Display Media Darusalam, Ucuk; Pamungkasari, Panca Dewi
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

A digital rainbow hologram (DRH) is a potential next-generation three-dimensional display media for the development of modern and smart electronics devices. It is one of the methods that can support the characteristic whereby a realistic display media occupies the space that the real object would have occupied. Since a rainbow hologram records a large amount of spatial or temporal frequency component from the object that represents the rainbow spectrum, a large amount of information needs to be decoded digitally. In this paper, to reconstruct a DRH, we propose a novel method based on the modulation of red, green, and blue spectral components of light by wavelet transform (WT) in the recording and reconstruction processes, which we digitally simulated in a computer using an algorithm. In the simulations, continuous WT (CWT) was based on Haar, Daubechies, Meyer, and Coiflet wavelets with a level set to be two. Based on the results of simulations using CWT, the optimum distance between object and hologram was 30 cm, and the maximum compression was 88.55%, which was achieved with Meyer wavelet. Moreover, optimal de-noising and optimal localization of spatial frequency component based on red, green, and blue spectral components were also achieved using the proposed method.
Study of ZnO Nanospheres Fabricated via Thermal Evaporation for Solar Cell Application Alia Azmi, Fatin Farisha; Sahraoui, Bouchta; Muzakir, Saifful Kamaluddin
Makara Journal of Technology Vol. 23, No. 1
Publisher : UI Scholars Hub

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Abstract

A solar cell is a device that absorbs light energy to generate electrical energy. A typical example of a solar cell is the quantum dot solar cell (QDSC), which consists of three main components: (i) fluorophore: the component that absorbs light and generates excited state electrons and holes, (ii) photoelectrode: the component that transports the excited state electron and prevents recombination of excited state electrons and holes, and (iii) electrolyte: the component that re-plenishes the vacancy left by the excited electron in the hole. Despite the increasing number of research in the QDSC field, to date, a device with significant photovoltaic efficiency has not been developed. In this study, the mechanism of electron transport in a zinc oxide (ZnO) photoelectrode was investigated. Two ZnO layers were fabricated using thermal evaporation method at different vacuum pressures (5 × 10-4 and 5 × 10-5 Torr). Two solar cells were fabricated using ZnO as photoelectrode, lead sulphide as fluorophore, and a mixture of carboxymethyl cellulose and polyvinyl alcohol as electrolyte. The cell which utilized the ZnO fabricated under 5 × 10-5 Torr showed the highest efficiency ( = 0.98%), with fill factor = 22.07%, short circuit current = 2.85 mA/m2, and open circuit voltage = 80.719 mV.
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
Publisher : UI Scholars Hub

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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%.

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