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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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Ionic Conductivity and Electrochemical Properties of Alginate–NN4NO3-Based Biopolymer Electrolytes for EDLC Application Mazuki, Norfatihah binti; Rasali, Nur Muhitul Jalilah; Sahraoui, Bouchta; Samsudin, Ahmad Salihin
Makara Journal of Technology Vol. 24, No. 1
Publisher : UI Scholars Hub

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Abstract

In this work, alginate doped with various contents of ammonium nitrate (NH4NO3) as a solid biopolymer electrolyte (SBE) was prepared via casting by using distilled water as a solvent. Impedance studies on alginate–NH4NO3 SBE films were conducted via impedance spectroscopy. The lowest bulk resistance (Rb) showed that the maximum ionic conductivity of the sample containing 25 wt.% NH4NO3 at ambient temperature (303 K) was 5.56 × 10−5 S cm−1. The temperature dependence of ionic conductivity was evaluated, and results confirmed that electrolytes followed an Arrhenius behavior. The highest conducting sample was fabricated into an electrical double-layer capacitor and characterized in terms of its electrochemical properties through cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurement. CV analysis indicated that specific capacitance decreased as the scan rate increased. Conversely, GCD analysis showed that specific capacitance almost remained unchanged for up to 5000 cycles.
Ethylene Carbonate and Polyethylene Glycol as Efficient Plasticizers in CMC-PVA-NH4NO3-Based Polymer Electrolyte Mohd Ali, Noor Saadiah; Nagao, Yuki; Samsudin, Ahmad Salihin
Makara Journal of Technology Vol. 24, No. 1
Publisher : UI Scholars Hub

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Abstract

This study investigated the influence of plasticizers (polyethylene glycol [PEG] and ethylene carbonate [EC]) on the ionic conduction of CMC-PVA-NH4NO3. Blended biopolymer electrolytes (BBEs) based on carboxymethyl cellulose–polyvinyl alcohol (CMC-PVA) doped with ammonium nitrate (NH4NO3) were obtained via casting solution technique incorporated with PEG and EC, which acted as plasticizers. Electrical impedance spectroscopy (EIS) was conducted to evaluate the effect of plasticization on the ionic conduction properties. The ionic conductivity improved from 1.70 × 10−3 S/cm for un-plasticized BBEs to 3.92 × 10−3 S/cm for plasticized BBEs with EC and 3.00 × 10−3 S/cm for plasticized BBEs with PEG. The improvement indicated that the plasticizers weakened the Coulombic force and promoted further dissociation in the ionic dopant. The highest ionic conductivity was achieved for BBEs plasticized with EC, thereby suggesting the suitability of EC as plasticizer in this present system. The BBE system showed the Arrhenius characteristic at elevated temperatures and demonstrated increasing ionic conductivity. Dielectric properties of all BBE systems were found to improve upon the addition of EC and PEG, demonstrating their correlation with ionic conductivity.
Synthesis of Epoxy Monoethanolamide from Bauhinia monandra Seed Oil Adewuyi, Adewale; Oderinde, Rotimi A.
Makara Journal of Technology Vol. 24, No. 1
Publisher : UI Scholars Hub

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Abstract

In this study, we synthesized epoxidised monoethanolamide (EMA) from Bauhinia monandra seed oil (BMO) via a simple reaction route. In this process, BMO was transesterified to obtain a mixture of methyl esters, which was subjected to a urea adduct complexation reaction. The unsaturated methyl esters (BME) from the urea adduct complexation reaction were then epoxidised using performic acid produced in situ in a one-pot reaction system. The epoxidised methyl esters were converted to EMA by reacting them with monoethanolamine (1:10). The progression of the reaction was monitored using Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, and the fatty acid composition was determined by gas chromatography. The results indicate that the most abundant fatty acid in BMO is C18:1 (25.70% ± 0.20%), with a degree of unsaturation of 49.00% ± 0.50%. After the urea adduct complexation reaction, the degree of unsaturation increased to 95.20% ± 0.10% with C18:2 (75.00% ± 0.10%) becoming the most dominant fatty acid. The oxirane oxygen content was found to be 5.50% ± 0.50%. The results of this study suggest that the urea adduct complexation reaction offers a potential means for increasing the unsaturation of fatty methyl esters. In addition, our findings show that EMA can be produced at low or room temperature.
Liquefaction Potential Analysis Based on Nonlinear Ground Response on the Coastline of Bengkulu City, Indonesia Mase, Lindung Zalbuin
Makara Journal of Technology Vol. 24, No. 1
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Abstract

This paper presents the study of the seismic response and liquefaction potential of the coastal area of Bengkulu City during the September 2007 Sumatra earthquake. The study is conducted by collecting site investigation data (standard penetration test) and applying input motion to observe soil response. Synthetic ground motion is generated by considering the important aspects of earthquakes, including focal depth, epicenter, earthquake source, and site classification. The synthetized ground motion is then used as the input motion in the seismic response analysis. The results of this analysis are spectral acceleration and peak ground acceleration at each depth. The resulting spectral acceleration is compared with that specified in the seismic design code of Indonesia (SNI 03-1726-2012). Liquefaction potential analysis is performed on the basis of the results of the seismic response analysis. Results show that spectral acceleration depends on soil type. A high soil density equates to a low spectral response. The designed spectral acceleration may still be considered for each borehole, especially for T (period) < 1. However, for T > 1, spectral acceleration should be prioritized, especially for high-rise building construction. The liquefaction analysis reveals that a shallow depth is vulnerable to liquefaction. In general, this study could give a better understanding on the implementation of seismic ground response for liquefaction potential analysis.
Current Status of Hydrothermal Treatment for Energy and Material Recovery Toward a Sustainable Post-consumer Material Cycle Lokahita, Baskoro; Aziz, Muhammad; Takahashi, Fumitake
Makara Journal of Technology Vol. 24, No. 1
Publisher : UI Scholars Hub

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Abstract

The demand for energy-efficient and environmentally friendly municipal solid waste (MSW) processing has increased in developing countries. The thermochemical process offers a fast and reliable solution to reutilize or reduce the volume of MSW. Hydrothermal treatment is a novel MSW treatment technology that is compatible with high-moisture-content feedstock. It involves the thermal degradation of MSW in pressurized water or steam, which promotes the disintegration of cellulosic and polymer materials. Recent advances have shown effective MSW conversion into homogenous solid hydrochar with higher energy density. Alkali and chlorine content, which causes issues in combustors, was successfully removed due to the washing effect of hydrothermal treatment. The possibility of activated carbon production also exists because the surface area is significantly increased after the treatment. This paper presents an overview of the latest development of hydrothermal treatment in the field of post-consumer waste and MSW treatment, with particular focus on the operating conditions and physicochemical characteristics of the hydrochar. Several experimental results from post-consumer waste feedstock were compiled and interpreted using principal component analysis to observe the effect of different operating conditions and feedstock during the hydrothermal process.
Comparison of Phytoremediation and Filtration for Diamond-mine-tailings Water Treatment Noor, M. Hafidhuddin; Rahman, Mijani; Gazali, Akhmad; Kania, Nia; Rahma, Aulia; Rampun, Erdina L.A.; Pratiwi, Amalia E.; Elma, Muthia
Makara Journal of Technology Vol. 24, No. 1
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Abstract

The water pollution caused by diamond mine activities can kill aquatic life. In this work, we used phytoremediation and filtration to treat pond water polluted by the tailings of a diamond mine located in South Kalimantan, Indonesia. Einchhornia crassipes (water hyacinth) was utilized as the biomass for the phytoremediation process. Gravel (10–15 mm) and sand (0.1–1 mm) were used as filter media in the simple filtration setup, using an up-flow system (bottom to top). In the experiment, 16 L of diamond tailing water was poured into five phytoremediation reactors (each 60 L in volume), which were then tested over seven days. A pretreatment analysis of the tailings water showed that its biochemical oxygen demand (BOD) of 8.9 mg L−1 and chemical oxygen demand (COD) of 22 mg L−1 exceeded the national maximum standards of 2 mg L−1 and 10 mg L−1, respectively. The experimental results demonstrate that both phytoremediation and filtration could increase the dissolved oxygen concentration (4.7 mg.L−1) and reduce the BOD (3.2 mg.L−1), COD (6.5 mg.L−1), Fe (0.6 mg.L−1), Mn (0.16 mg.L−1), and ammonia (0.63 mg.L−1) concentrations from those measured in the raw diamond-mine-tailings water. The phytoremediation performance was better than that of filtration. The COD values were successfully reduced to the permissible limit, although the other parameters still failed to meet the government water quality regulation requirements.
Effect of Catholyte Concentration on Current Production During Chocolate Industry Wastewater Treatment by a Microbial Fuel Cell Wulan, Diana Rahayuning; Notodarmojo, Suprihanto
Makara Journal of Technology Vol. 24, No. 2
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Abstract

Microbial fuel cells (MFCs) use bacteria as a catalyst to oxidize organic and/or inorganic substrates and produce electric currents. Wastewater could function as an electron donor in the anode chamber and, thus, represents a very promising energy source. Catholytes, as electron acceptors, influence power production in MFCs by increasing the availability of electrons. The present research aims to determine the influence of catholyte concentration on current production in an aerobic two-chamber MFC. Aerobic treatment was carried out in the two-chamber MFC operated in an incubator at 37  1 °C with and without aeration in the cathode chamber. Wastewater from the chocolate industry was used as a substrate and oxidized by using a bacterial consortium isolated from the sludge wastewater itself. The catholytes used were 0.01, 0.05, 0.1, and 0.3 N NaCl. In the presence of NaCl, the chemical oxygen demand (COD) removal efficiency in the cathode chamber of the MFC was approximately 65%–83% without aeration and 76%–89% with aeration after 72 hours. The current density increased as the catholyte concentration increased to 0.05 N, after which the oxidation process shifted from the anode chamber to the cathode chamber. Addition of O2 to the cathode chamber influenced current production.
Evaluation of IL-17A and IL-17F Gene Expression in Peripheral Blood Mononuclear Cells in Different Clinical Stages of Chronic Hepatitis B Infection in an Iranian Population Kolagar, Tannaz Akbari; Mohebbi, Seyed Reza; Ashrafi, Fatemeh; Shoraka, Shahrzad; Aghdaei, Hamid Asadzadeh; Zali, Mohammad Reza
Makara Journal of Technology Vol. 24, No. 2
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Abstract

Hepatitis B virus (HBV) infection is one of the main causes of liver damage, which can also lead to chronic hepatitis B (CHB) infection. More than 240 million individuals worldwide are chronic carriers of HBV. Among individuals with CHB who are untreated, approximately 15% – 40% will progress to liver cirrhosis or cancer. The interactions between HBV and host immune response play significant roles in the progression of CHB. CHB can be generally divided into four different clinical phases: immune tolerance (IT), immune clearance, inactive carrier, and Hepatitis B surface antigen (HBsAg)-negative reactivation phase (ENEG). Many studies showed that interleukins play important roles in anti-viral immunity and pathogenesis of chronic hepatitis. However, the relations between clinical phases of CHB and host immune transcriptome remain unclear. In this study, we aimed to investigate the expression of interleukin-17A (IL-17A) and IL-17F genes in the peripheral blood mononuclear cells (PBMCs) of patients with CHB through different clinical stages. Results were compared with the control group, which comprised individuals with no history of pre-existing medical conditions. This case–control study was carried out on 32 patients with CHB as the case group and 32 healthy individuals as the control group. According to clinical data, CHB cases were divided into two groups: active (n = 22) and inactive (n = 11). PBMC samples were obtained from all groups. After total RNA extraction and cDNA synthesis, real-time PCR was used to determine IL-17A and IL-17F expression levels. The results were analyzed by REST software, SPSS, and GraphPad Prism. The IL-17A and IL-17F gene expression levels were observed to be significantly higher in the CHB group than in the control group (IL-17A: P = 0.0013; IL-17F: P = 0.0103). The active phase group (including IT, clearance, and reactivation samples) significantly increased in comparison with the inactive phase (IL-17A: P = 0.000; IL-17F: P = 0.000). The study suggests that IL-17A and IL-17F do not only activate inflammation but are also involved in HBV-related disease progression and chronicity. Thus, mRNA levels of IL-17A and IL-17F could be used as a biomarker to diagnose CHB infection and distinguish between the active CHB phase from the inactive phase.
Redesign of Product Packaging with Kansei Engineering: Empirical Study on Small-medium Enterprises in Indonesia Suzianti, Amalia; Aldianto, A.
Makara Journal of Technology Vol. 24, No. 2
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Abstract

Small-medium enterprises (SMEs) in Indonesia have been proven to be one of the important pillars of the national economy. Unfortunately, some problems hinder their development, and one of the critical problems is the quality of product packaging. The packages of SME products are considered poor, dirty, and unattractive. Packaging problem is one of the factors why consumers are less interested in buying and why SME products always lose in the competition with other products. This study discusses how to employ Kansei engineering to design better SME product packaging with a focus on psychological (affective) aspects. This research concludes that there are four components that represent consumers’ desires: Attractiveness, Robustness, Handy & Green, and Lightness. The final result of this research is the creation of four new designs for a product package that satisfies each of the above components.
Effect of Landfill Leachates on Some Water Quality Indicators of Selected Surface Water and Groundwater at Ilokun, Ado-Ekiti, Nigeria Omofunmi, Olorunwa; Satimehin, Adesola; Oloye, Abraham; Umego, Okwunna
Makara Journal of Technology Vol. 24, No. 2
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This study was conducted to examine the impact of dumpsites on the quality of groundwater and surface water. The water samples and leachates were collected from dumpsites in respective zones. The physicochemical properties of the samples were examined and determined in accordance with the standards of the American Public Health Association. Results indicated that the groundwater and surface water that are close to the dumpsites have an electrical conductivity of 385 and 245 Sd/cm, total dissolved solids of 168 and 128 mg/L, a turbidity of 4.6 and 22 NTU, a total alkalinity of 103 and 50 mg/L, a total hardness of 120 and 80 mg/L, Ca concentration of 44 and 14 mg/L, Mg concentration of 0.2 and 15 mg/L, SO4 concentration of 4 and 42 mg/L, Cl concentration of 38 and 16 mg/L, and NO3 concentration of 6 and 8 mg/L, respectively. Moreover, the water near the dumpsites had higher elevated physicochemical properties compared with those far from the dumpsites; in addition, they were significantly different (p ≥ 0.05). Hence, the closer the groundwater and surface water to the dumpsite, the greater the negative impact on the physicochemical properties of water. The pH concentration in leachate serves as an indicator for the age and mineralization status of dumpsites, and it influences the other chemical properties of the leachate. Furthermore, the pH concentration in leachate is inversely proportional to the concentration of Ca, Mg, and SO4 in the study area.

Page 40 of 49 | Total Record : 485

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