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Articles 181 - 210 of 606

Full-Text Articles in Computer Engineering

Ionic Conductivity And Electrochemical Properties Of Alginate–Nn4no3-Based Biopolymer Electrolytes For Edlc Application, Norfatihah Binti Mazuki, Nur Muhitul Jalilah Rasali, Bouchta Sahraoui, Ahmad Salihin Samsudin Apr 2020

Ionic Conductivity And Electrochemical Properties Of Alginate–Nn4no3-Based Biopolymer Electrolytes For Edlc Application, Norfatihah Binti Mazuki, Nur Muhitul Jalilah Rasali, Bouchta Sahraoui, Ahmad Salihin Samsudin

Makara Journal of Technology

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 …


Synthesis Of Epoxy Monoethanolamide From Bauhinia Monandra Seed Oil, Adewale Adewuyi, Rotimi A. Oderinde Apr 2020

Synthesis Of Epoxy Monoethanolamide From Bauhinia Monandra Seed Oil, Adewale Adewuyi, Rotimi A. Oderinde

Makara Journal of Technology

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 …


Ethylene Carbonate And Polyethylene Glycol As Efficient Plasticizers In Cmc-Pva-Nh4no3-Based Polymer Electrolyte, Noor Saadiah Mohd Ali, Yuki Nagao, Ahmad Salihin Samsudin Apr 2020

Ethylene Carbonate And Polyethylene Glycol As Efficient Plasticizers In Cmc-Pva-Nh4no3-Based Polymer Electrolyte, Noor Saadiah Mohd Ali, Yuki Nagao, Ahmad Salihin Samsudin

Makara Journal of Technology

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 …


Current Status Of Hydrothermal Treatment For Energy And Material Recovery Toward A Sustainable Post-Consumer Material Cycle, Baskoro Lokahita, Muhammad Aziz, Fumitake Takahashi Apr 2020

Current Status Of Hydrothermal Treatment For Energy And Material Recovery Toward A Sustainable Post-Consumer Material Cycle, Baskoro Lokahita, Muhammad Aziz, Fumitake Takahashi

Makara Journal of Technology

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 …


Liquefaction Potential Analysis Based On Nonlinear Ground Response On The Coastline Of Bengkulu City, Indonesia, Lindung Zalbuin Mase Apr 2020

Liquefaction Potential Analysis Based On Nonlinear Ground Response On The Coastline Of Bengkulu City, Indonesia, Lindung Zalbuin Mase

Makara Journal of Technology

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 …


Comparison Of Phytoremediation And Filtration For Diamond-Mine-Tailings Water Treatment, M. Hafidhuddin Noor, Mijani Rahman, Akhmad Gazali, Nia Kania, Aulia Rahma, Erdina L.A. Rampun, Amalia E. Pratiwi, Muthia Elma Apr 2020

Comparison Of Phytoremediation And Filtration For Diamond-Mine-Tailings Water Treatment, M. Hafidhuddin Noor, Mijani Rahman, Akhmad Gazali, Nia Kania, Aulia Rahma, Erdina L.A. Rampun, Amalia E. Pratiwi, Muthia Elma

Makara Journal of Technology

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 …


Architecture And Trilogy Of (Law, Theory And Hypothesis), Ahmed Hashim Hameed Feb 2020

Architecture And Trilogy Of (Law, Theory And Hypothesis), Ahmed Hashim Hameed

Al-Esraa University College Journal for Engineering Sciences

The general cognitive expositions had focused on the study of the general knowledge frameworks of the field of architecture, with both concepts that influencing and influenced by them, which used to contain them without referring to their intellectual origins in order to understand their general effect and their role in the cognitive enrichment to the architectural field. This, in return, showed the importance of direction to study the role, influence and effect of trilogy (Law, theory and hypothesis) in the field of architecture, according to their general reality knowledge and their specific theoretical and intellectual characteristics. This research deals with …


The Impact Of Spatial Location Of Functions To Identify Architectural Forms As A Landmark (Case Study - Contemporary Islamic Architecture -), Ibtisam Abdulelah Mohammed Al Khafaji, Maha Haki Ismaeil Feb 2020

The Impact Of Spatial Location Of Functions To Identify Architectural Forms As A Landmark (Case Study - Contemporary Islamic Architecture -), Ibtisam Abdulelah Mohammed Al Khafaji, Maha Haki Ismaeil

Al-Esraa University College Journal for Engineering Sciences

This research discusses the impact of spatial location of functions inside architectural form to enhance visual legibility and how it can improve the possibilities of identifying them as a landmark. The absence of a clear conceptual frame which can be used to describe this impact forms the basic research problem. The objective aim of the research is to clarify and describe this impact. To achieve this objective aim, an analytical process was used. We supposed that spatial location of functions enhances visual legibility of forms, then improves our possibility of identifying them as a landmark. For applying the conceptual frame, …


Effect Of Loading Level Of Hybrid Reinforced Concrete Deep Beams Under Repeated Loading, Sawsan Akram Hassan, Ghsoon Ali Faroun Feb 2020

Effect Of Loading Level Of Hybrid Reinforced Concrete Deep Beams Under Repeated Loading, Sawsan Akram Hassan, Ghsoon Ali Faroun

Al-Esraa University College Journal for Engineering Sciences

This research is devoted to investigating the experimental and theoretical behavior of hybrid deep beams under monotonic and repeated two-point loading. The dimensions and the flexural reinforcement of the deep beams were kept constant. In this work, the idea of a hybrid beam is completely different. Two types of concrete were used but not in the cross-section. The first type, which is fiberous concrete (FC), was used in casting beam sides (shear spans), while the second type was conventional concrete (CC) which was used in the middle portion of the beam (between two shear spans). This was done to strengthen …


Reverse Osmosis Method For Sulphate Re-Moval From Treated Wastewater Of Al-Doura Refinery, Rana Mohammed Rasheed Feb 2020

Reverse Osmosis Method For Sulphate Re-Moval From Treated Wastewater Of Al-Doura Refinery, Rana Mohammed Rasheed

Al-Esraa University College Journal for Engineering Sciences

The treated wastewater by the industrial Wastewater Treatment Plant (WWTP) commonly named (INGECO) in Al-Doura refinery suffers from highly sulfate concentrations that exceed the EPA specified limits of 250 mg/L. Therefore, laboratory water quality historical data have been reviewed and analyzed to determine the annual rate, maximum, and peak sulfate concentrations that were found to be 360 mg/L, 425 mg/L, and 550 mg/L, respectively. Through field inspection aimed at specifying the reasons for the high sulfate concentrations in the wastewater of most refinery process units, it was found that the maximum required sulfate remaining concentration should not exceed 10 mg/L …


Comparison Between Regular And Irregular Configuration In Earthquake Resistant Design, Ali Nur-Aldeen Azeez, Ali Mohsen Jaafer Al-Khafaji Feb 2020

Comparison Between Regular And Irregular Configuration In Earthquake Resistant Design, Ali Nur-Aldeen Azeez, Ali Mohsen Jaafer Al-Khafaji

Al-Esraa University College Journal for Engineering Sciences

Earthquake-resistant design is one of the greatest challenges that must be considered by the Architect because it is a serious natural disaster that affects the stability and durability of the building. Due to the connection between the seismic behavior of buildings with its formal configuration and the differences in seismic resistance between regular and irregular buildings, the research problem presented as the confusion of seismic behavior of irregular buildings and their difference from the regular buildings when earthquakes occur. The aim of the research is to clarify the differences between regular and irregular configurations, also clarifying the design considerations in …


Pedestrian Movement Within Residential Areas, Abd Alali Hamza Mohamed Feb 2020

Pedestrian Movement Within Residential Areas, Abd Alali Hamza Mohamed

Al-Esraa University College Journal for Engineering Sciences

The network of transport within residential areas, especially within residential neighborhoods, consists mainly of roads designed to provide relative safety for road users and to prioritize solutions that enhance safety. It is believed that the pedestrian movement network should be separated from the car movement network, with a focus on road design, pedestrian paths, and the types of vehicles used in these areas to ensure safety. This research explores the solutions developed in the planning of roads and walkways in traditional housing schemes within the urban fabric of old cities. It examines the approaches and conclusions of modern models of …


Tabletop Mechanical Tester, Jamie Dombroski, Brian English, Richard Leffler, Andrew Shirk Jan 2020

Tabletop Mechanical Tester, Jamie Dombroski, Brian English, Richard Leffler, Andrew Shirk

Williams Honors College, Honors Research Projects

The need for hands-on and face-to-face experiences in the engineering classroom is very great. The equations, principles, and concepts can all be learned, but without the visual and tactile application, these don’t always sink in or become concrete. A small-scale tensile test machine was designed, sourced, manufactured, and tested for the purpose of being applied in classroom settings to provide this experience to engineering students. Extensive research was performed concerning tensile machines on the market, the essential elements of which are the load cell, grips, crosshead, extensometer, motor, and frame. The raw materials for the frame were purchased and drawings …


A New Synthesized Microalloys Steel Ods Of High Amplitude Ultrasonically Irradiation, Marzuki Silalahi, Hanif Abdurrahman Wicaksana, Ferhat Aziz, Syahfandi Ahda, Mohamad Riza Iskandar Dec 2019

A New Synthesized Microalloys Steel Ods Of High Amplitude Ultrasonically Irradiation, Marzuki Silalahi, Hanif Abdurrahman Wicaksana, Ferhat Aziz, Syahfandi Ahda, Mohamad Riza Iskandar

Makara Journal of Technology

Micropowders of oxide-dispersion-strengthened (ODS) steel have been synthesized using the ultrasonic irradiation method with variations in amplitude. The ultrasonic irradiation process is performed for 50 h at a frequency of 20 kHz with 40%, 50%, and 60% amplitudes in toluene solution. The formation of Fe-Cr microalloys in the preparation of Fe- 15Cr-0.5Y2O3 powder was analyzed using SEM-EDS, X-ray diffraction (XRD), and TEM-EDS. The percentage of Fe- Cr phase mass fraction of ODS steel micropowder formed during ultrasonic irradiation with 40%:50%:60% amplitude was 12.2%:34.1%:22.1%, with 25.67:77.02:38.51 nm crystallite size. The crystallite size at 50% amplitude was the largest, and the diffusion …


Comprehensive Inspection On The Experimental Ferritic Stainless Steel By Means Of Transmission Electron Microscopy And Neutron Diffraction Techniques, Parikin Parikin, Mohammad Dani, Riza Iskandar, Aziz Khan Jahja, Andon Insani, Joachim Mayer Dec 2019

Comprehensive Inspection On The Experimental Ferritic Stainless Steel By Means Of Transmission Electron Microscopy And Neutron Diffraction Techniques, Parikin Parikin, Mohammad Dani, Riza Iskandar, Aziz Khan Jahja, Andon Insani, Joachim Mayer

Makara Journal of Technology

The field of physical metallurgy is one of the primary beacons that guide alloy developments for multipurpose materials such as the in-core structure materials for pressure vessel components and heat exchangers. The surface microstructure of new ferritic steel with significant local constituent materials was characterized by high resolution powder neutron diffractometer (HRPD) and transmission electron microscope (TEM), combined with the energy dispersive X-ray spectroscopy (EDX). The alloy contains73% Fe, 24% Cr, 2% Si, 0.8% Mn, and 0.1% Ni, in %wt. The charge materials were melted by the casting techniques. The neutron diffractograms obtained shows five dominant diffraction peaks at (110), …


Study On Antibacterial Of Chitosan/Hydroxyapatite Doped Magnesium Composite As A Material For Bone Graft Applications, Andromeda Dwi Laksono, Teodoro A. Amatosa, Jr., Hilda Pebrianti Octaviana Sitorus, Wentika Putri Kusuma Asih, Sulistijono Sulistijono Dec 2019

Study On Antibacterial Of Chitosan/Hydroxyapatite Doped Magnesium Composite As A Material For Bone Graft Applications, Andromeda Dwi Laksono, Teodoro A. Amatosa, Jr., Hilda Pebrianti Octaviana Sitorus, Wentika Putri Kusuma Asih, Sulistijono Sulistijono

Makara Journal of Technology

Hydroxyapatite (HAp) is one of the constituent minerals of bone and teeth, that has been widely used for synthesizing bone graft. Due to the limitation on properties of the hydroxyapatite, it is doping with Magnesium (HAp-Mg). The addition of Chitosan (Chi) was expected to improve the antibacterial properties of HAp-Mg. The present research aims to study the influence of Chitosan with 0, 5, 15, and 25 wt% addition on biocompatibility properties of Chi/HAp-Mg composite. HAp-Mg was synthesized using the sol-gel method; meanwhile, Chi/HAp-Mg composite was manufactured by mixing Chitosan in acetic acid, and HAp-Mg was added into the mixture. The …


Evaluation Of Primal-Dual Splitting Algorithm For Mri Reconstruction Using Spatio-Temporal Structure Tensor And L1-2 Norm, Mia Rizkinia, Masahiro Okuda Dec 2019

Evaluation Of Primal-Dual Splitting Algorithm For Mri Reconstruction Using Spatio-Temporal Structure Tensor And L1-2 Norm, Mia Rizkinia, Masahiro Okuda

Makara Journal of Technology

Magnetic resonance imaging (MRI) is an essential medical imaging technique which is widely used for medical research and diagnosis. Dynamic MRI provides the observed object visualization through time and results in a spatiotemporal signal. The image sequences often contain redundant information in both spatial and temporal domains. To utilize this characteristic, we propose a spatio-temporal reconstruction approach based on compressive sensing theory. We apply spatio-temporal structure tensor using nuclear norm, in addition to the wavelet sparsity regularization. The spatio-temporal structure tensor is a matrix that consists of gradient components of the MRI data w.r.t the spatial and temporal domains. For …


Influence Of Nh4f In Dextran Based Biopolymer Electrolytes: Conductivity And Electrical Analysis, Muhamad Hafiz Hamsan, Mohd Fakhrul Zamani Kadir, Shujahadeen Bakar Aziz, Muhammad Amirul Solihin Azha, Saifful Kamaluddin Muzakir Dec 2019

Influence Of Nh4f In Dextran Based Biopolymer Electrolytes: Conductivity And Electrical Analysis, Muhamad Hafiz Hamsan, Mohd Fakhrul Zamani Kadir, Shujahadeen Bakar Aziz, Muhammad Amirul Solihin Azha, Saifful Kamaluddin Muzakir

Makara Journal of Technology

Dextran polymer host was doped with different concentrations of ammonium fluoride (NH4F) via casting technique. In this present work, dextran-NH4F film has been employed to investigate the ionic conductivity using electrochemical impedance spectroscopy from 50 to 5 MHz. The highest room temperature conductivity is achieved at (2.33 ± 0.76) × 10-3 S cm-1 with 40 wt.% NH4F. The electrolyte is found to obey Arrhenius rule at high temperature with activation energy of 0.21 eV. Dielectric analysis has been performed to obtain better understanding on the conductivity pattern. The dielectric parameters e.g. ɛreal, ɛimag, Mreal, and Mimag have been tested as …


Acute Toxicitystudy Of Choline Based Ionic Liquids Towards Danio Rerio Fish And The Aggregation Behavior Of Their Binary Mixtures, Mansoor Ul Hassan Shah, Nasruddin Nasruddin, Suzana Bt Yusup, Muhammad Moniruzzaman Dec 2019

Acute Toxicitystudy Of Choline Based Ionic Liquids Towards Danio Rerio Fish And The Aggregation Behavior Of Their Binary Mixtures, Mansoor Ul Hassan Shah, Nasruddin Nasruddin, Suzana Bt Yusup, Muhammad Moniruzzaman

Makara Journal of Technology

Marine oil spills are effectively controlled by chemical dispersants. However, the toxicity associated with it reduce its employment in marine environment. To overcome this limitation, the acute toxicity of choline based ionic liquids was evaluated as a potential low toxic variant for oil spill remediation. Further, the aggregation behavior of the individual as well as their binary mixtures was also evaluated by employing tensiometry technique. The half-lethal concentration, LC50on zebrafish (Danio rerio) of three choline based ionic liquids showed that the studied ionic liquids (ILs) fall in the range of “practically nontoxic” ( 100-1000 mg L-1).Various micellar properties showed that …


Neutron Diffraction Study Of Multiferroic 0.6nife2o4/0.4batio3 Composite, Engkir Sukirman, Yosef Sarwanto, Syahfandi Ahda, Andon Insani Dec 2019

Neutron Diffraction Study Of Multiferroic 0.6nife2o4/0.4batio3 Composite, Engkir Sukirman, Yosef Sarwanto, Syahfandi Ahda, Andon Insani

Makara Journal of Technology

Neutron diffraction study on the 0.6NiFe2O4/0.4BaTiO3 multiferroic composite has been carried out. The 0.6NiFe2O4/0.4BaTiO3 multiferroic composites have been synthesized by solid reaction method. In this study, 20 g of BaTiO3 (BTO) and 20 g of NiFe2O4 (NFO) compounds were prepared from the powder raw materials of BaO3 and TiO2 for BTO, and NiO and Fe2O3 for NFO. Furthermore, both BTO and NFO were each crushed for 5 hours using High Energy Milling (HEM). Then the BTO and NFO were calcined in the furnace at 950 °C/5 hours and 900 °C/5 hours, respectively. Both NFO and BTO precursors were manually mixed …


A Study Of The Electron Regeneration Efficiency Of Solar Cells Fabricated Using Cmc/Pva-, Alginate-, And Xanthan-Based Electrolytes, Nur Farha Shaafi, Saifful Kamaluddin Muzakir, Bouchta Sahraoui Aug 2019

A Study Of The Electron Regeneration Efficiency Of Solar Cells Fabricated Using Cmc/Pva-, Alginate-, And Xanthan-Based Electrolytes, Nur Farha Shaafi, Saifful Kamaluddin Muzakir, Bouchta Sahraoui

Makara Journal of Technology

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 …


Use Of The “Dnachecker” Algorithm For Improving Bioinformatics Research, Nausheen Bhat, Ezra Bernadus Wijaya, Arli Aditya Parikesit Aug 2019

Use Of The “Dnachecker” Algorithm For Improving Bioinformatics Research, Nausheen Bhat, Ezra Bernadus Wijaya, Arli Aditya Parikesit

Makara Journal of Technology

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. …


Study Of Ecological Design Of Residential Complexes Using Spss To Elevate Resident Satisfaction, Soheil Malekpour Kolbadinejad, V. Malekpour Ravasjan, A. Darvish Aug 2019

Study Of Ecological Design Of Residential Complexes Using Spss To Elevate Resident Satisfaction, Soheil Malekpour Kolbadinejad, V. Malekpour Ravasjan, A. Darvish

Makara Journal of Technology

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.


Adsorption Of Heavy Metal Ions By Oil Palm Decanter Cake Activated Carbon, Mohd. Ezreeza Mohamed Yusoff, Juferi Idris, Nahrul Hayawin Zainal, Mohamad Faizal Ibrahim, Suraini Abd-Aziz Aug 2019

Adsorption Of Heavy Metal Ions By Oil Palm Decanter Cake Activated Carbon, Mohd. Ezreeza Mohamed Yusoff, Juferi Idris, Nahrul Hayawin Zainal, Mohamad Faizal Ibrahim, Suraini Abd-Aziz

Makara Journal of Technology

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. …


Experimental Evaluation Of Three Different Humidity Conditions To Physical And Mechanical Properties Of Three Different Mixtures Of Unfired Soil Bricks, Heru Purnomo, Srikandi Wahyu Arini Aug 2019

Experimental Evaluation Of Three Different Humidity Conditions To Physical And Mechanical Properties Of Three Different Mixtures Of Unfired Soil Bricks, Heru Purnomo, Srikandi Wahyu Arini

Makara Journal of Technology

Unfired brick is considered as a more environmentally friendly material than fired brick. It has lower mechanical properties than that of fired brick where humidity influences both bricks. Physical and mechanical properties of unfired bricks made of three kinds of mixtures were studied experimentally under three humidity conditions. The first kind of unfired brick was made only with soil and water while the second type was made of a mixture of soil, water and lime, and the third type was a mixture of soil, water, lime and uniform treated coir where 4% of lime mass was substituted with coir mass. …


Component Analysis And Antiangiogenic Activity Of Thailand Stingless Bee Propolis, Eriko Ishizu, Sari Honda, Tosihro Ohta, Boonyadist Vongsak, Shigenori Kumazawa Aug 2019

Component Analysis And Antiangiogenic Activity Of Thailand Stingless Bee Propolis, Eriko Ishizu, Sari Honda, Tosihro Ohta, Boonyadist Vongsak, Shigenori Kumazawa

Makara Journal of Technology

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, …


3d Fdtd Method For Modeling Of Seismo-Electromagnetics Disturbance On Crustal Earth, Nabila Husna Shabrina, Yasuhide Hobara, Achmad Munir Aug 2019

3d Fdtd Method For Modeling Of Seismo-Electromagnetics Disturbance On Crustal Earth, Nabila Husna Shabrina, Yasuhide Hobara, Achmad Munir

Makara Journal of Technology

The paper deals with the modelling of seismo-electromagnetics disturbance on the crustal earth by use of threedimensional (3D) finite-difference time-domain (FDTD) method. The model is built up by discretizing the frontier geographical region between Java Island and Sumatra Island in a cylindrical coordinate system-based 3D object. The proposed method is applied to compute and analyze electromagnetics (EM) fields of the observed very low frequency (VLF) wave used for the investigation. Boundary condition of uniaxial perfectly matched layer (UPML) are applied surrounding the area of computation for truncating the object of simulation. The investigation are focused on the propagation time of …


Wavelet Transform On Digital Rainbow Hologram Based On Spectral Compression For Quality Enhancement In 3d Display Media, Ucuk Darusalam, Panca Dewi Pamungkasari Apr 2019

Wavelet Transform On Digital Rainbow Hologram Based On Spectral Compression For Quality Enhancement In 3d Display Media, Ucuk Darusalam, Panca Dewi Pamungkasari

Makara Journal of Technology

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 …


Molecularly Conductive Behavior Of Blended Polymer Electrolyte-Based Cmc/Pva, Noor Saadiah Mohd Ali, Dishen Zhang, Yuki Nagao, Ahmad Salihin Samsudin Apr 2019

Molecularly Conductive Behavior Of Blended Polymer Electrolyte-Based Cmc/Pva, Noor Saadiah Mohd Ali, Dishen Zhang, Yuki Nagao, Ahmad Salihin Samsudin

Makara Journal of Technology

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-), …


Multistage Sonication Effect On The Composition And Properties Of Degraded Chitosan Product, Nurul Laili Arifin, Emma Savitri, Anjar Indah, Fesa Putra, Sumarno Sumarno Apr 2019

Multistage Sonication Effect On The Composition And Properties Of Degraded Chitosan Product, Nurul Laili Arifin, Emma Savitri, Anjar Indah, Fesa Putra, Sumarno Sumarno

Makara Journal of Technology

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) …