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Articles 91 - 120 of 641

Full-Text Articles in Civil Engineering

Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte, Nurhasniza Mamajan Khan, Noor Saadiah Mohd Ali, Ahmad Faizrin Ahmad Fuzlin, Ahmad Salihin Samsudin Dec 2020

Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte, Nurhasniza Mamajan Khan, Noor Saadiah Mohd Ali, Ahmad Faizrin Ahmad Fuzlin, Ahmad Salihin Samsudin

Makara Journal of Technology

This study aims to produce a solid biopolymer electrolyte (SBE) by doping ammonium chloride (NH4Cl) into alginate. Solution casting was used to prepare the alginate–NH4Cl SBE system. Electrical impedance spectroscopy was performed to analyze the electrical properties of the SBE under the applied frequency range of 50 Hz–1 MHz. The incorporation of 8 wt.% NH4Cl enhances the ionic conductivity of the SBE up to 3.18 × 10-7 S/cm at ambient room temperature. Fourier transform infrared spectroscopy shows that complexation occurs between the hydroxyl (-OH), carboxylate (COO-) and ether linkage (C-O-C) functional groups due to the formation of inter- and intra-molecular …


A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution, Triati Dewi Kencana Wungu, Meqorry Yusfi, Suprijadi Suprijadi Dec 2020

A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution, Triati Dewi Kencana Wungu, Meqorry Yusfi, Suprijadi Suprijadi

Makara Journal of Technology

In this study, density functional theory (DFT) method is used to investigate the possibility of using a smectite clay mineral called montmorillonite (MMT) in reducing heavy metals, such as Cd, through Cd adsorption. The mechanism of Cd adsorption in MMT is observed theoretically, and the tetrahedrally isomorphic substitution on the upper layer of MMT is considered to observe the role of Al and Fe in strengthening Cd adsorption. Two types of MMT are modeled in this study: Al-MMT and Fe-MMT. The Al-MMT means that Al substitutes one atom in the upper tetrahedral layer of MMT, while Fe-MMT means that Fe …


Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes, Ahmad Faizrin Fuzlin, Bouchta Sahraoui, Ahmad Salihin Samsudin Dec 2020

Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes, Ahmad Faizrin Fuzlin, Bouchta Sahraoui, Ahmad Salihin Samsudin

Makara Journal of Technology

This research presents the influence of lithium bromide (LiBr) on the electrical properties of alginate in bio-based polymer electrolytes (BBPEs) system. Bio-based alginate was prepared using the solution casting technique with various LiBr compositions. The ionic conductivity and electrical properties of the prepared BBPEs samples were studied using electrical impedance spectroscopy over a frequency range of 50 Hz–1 MHz. A maximum ionic conductivity of 7.46 × 10−5 S cm-1 was obtained for a sample containing 15 wt. % lithium bromide-doped alginate BBPEs at ambient temperature (303 K). The electrical analysis revealed that the most conductive sample based on alginate-LiBr BBPEs …


Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading, Gholamreza Abdollahzadeh, Hadi Faghihmaleki, Hamed Hamidi Jamnani, Atefeh Ebrahimi Bardar Dec 2020

Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading, Gholamreza Abdollahzadeh, Hadi Faghihmaleki, Hamed Hamidi Jamnani, Atefeh Ebrahimi Bardar

Makara Journal of Technology

In this paper, we evaluated the effect of viscoplastic dampers on the response of steel frames under blast loading. We used SAP2000 software and link elements to investigate the responses of nine-story steel frames with and without dampers. The proposed viscoplastic damper is a new type of viscous damper. The application of this damper is based on the availability of its constituent materials. The damper acts as a viscoelastic damper at low levels of vibration, but it acts as a combination of viscoelastic operator and metal-yielding device at extreme levels of vibration. With respect to the height of the structure, …


Effect Of Pvdf-Ca Ratio On Electrospun Membrane For Water–Oil Filtration Application, Mohamad Haziq Alias, Izan Izwan Misnon, Rajan Jose Nov 2020

Effect Of Pvdf-Ca Ratio On Electrospun Membrane For Water–Oil Filtration Application, Mohamad Haziq Alias, Izan Izwan Misnon, Rajan Jose

Makara Journal of Technology

Oil spillage and generation of industrial water–oil wastewater mixture ignite a focus on filtration technology. Electrospinning technique provides a versatile route in producing tunable diameter and pores in nanofiber filtration membrane development. In this work, polyvinylidene difluoride (PVDF) and cellulose acetate (CA) electrospun membrane at different concentration ratios were synthesized for water–oil filtration application. The polymeric solutions were characterized using viscometer and conductivity testing, whereas the membranes were analyzed using contact angle, tensile test, scanning electron microscopy (SEM), and filtration testing of oil (dichloromethane). Conductivity test showed a decreased conductivity along with decrement of CA ratio in the polymeric solution. …


Effect Of Landfill Leachates On Some Water Quality Indicators Of Selected Surface Water And Groundwater At Ilokun, Ado-Ekiti, Nigeria, Olorunwa Omofunmi, Adesola Satimehin, Abraham Oloye, Okwunna Umego Nov 2020

Effect Of Landfill Leachates On Some Water Quality Indicators Of Selected Surface Water And Groundwater At Ilokun, Ado-Ekiti, Nigeria, Olorunwa Omofunmi, Adesola Satimehin, Abraham Oloye, Okwunna Umego

Makara Journal of Technology

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 …


Effect Of Catholyte Concentration On Current Production During Chocolate Industry Wastewater Treatment By A Microbial Fuel Cell, Diana Rahayuning Wulan, Suprihanto Notodarmojo Nov 2020

Effect Of Catholyte Concentration On Current Production During Chocolate Industry Wastewater Treatment By A Microbial Fuel Cell, Diana Rahayuning Wulan, Suprihanto Notodarmojo

Makara Journal of Technology

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 …


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, Tannaz Akbari Kolagar, Seyed Reza Mohebbi, Fatemeh Ashrafi, Shahrzad Shoraka, Hamid Asadzadeh Aghdaei, Mohammad Reza Zali Nov 2020

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, Tannaz Akbari Kolagar, Seyed Reza Mohebbi, Fatemeh Ashrafi, Shahrzad Shoraka, Hamid Asadzadeh Aghdaei, Mohammad Reza Zali

Makara Journal of Technology

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 …


Redesign Of Product Packaging With Kansei Engineering: Empirical Study On Small-Medium Enterprises In Indonesia, Amalia Suzianti, A. Aldianto Nov 2020

Redesign Of Product Packaging With Kansei Engineering: Empirical Study On Small-Medium Enterprises In Indonesia, Amalia Suzianti, A. Aldianto

Makara Journal of Technology

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 …


Microstrip Filters: A Review Of Different Filter Designs Used In Ultrawide Band Technology, Hussain Bohra, Giriraj Prajapati Nov 2020

Microstrip Filters: A Review Of Different Filter Designs Used In Ultrawide Band Technology, Hussain Bohra, Giriraj Prajapati

Makara Journal of Technology

In this study, optimization techniques applied in designing microstrip bandpass ultra-wideband (UWB) filters are presented. Optimization based on various defected ground structure techniques, resonator designs, and type of dielectric materials is discussed. Microstrip bandpass filters implemented at UWB frequency bands used in wireless communication systems have key features to control frequency response in passband and stopband. Optimization techniques are studied to attain optimum performance of bandpass microstrip filters to ensure minimum insertion loss, high selectivity, compactness, sharp transitions at cut-off frequencies, high return loss, and excellent linearity. Extensive study shows that proper selection of fabrication techniques and type of material …


Performance-Shaping Factors Of Personnel Performing Evacuation And Escape On Offshore Installations In Tropical, Norafneeza Norazahar, Nur Azizah Arryanie Morshidi, Arshad Ahmad, Wijayanuddin Mohd Ali Nov 2020

Performance-Shaping Factors Of Personnel Performing Evacuation And Escape On Offshore Installations In Tropical, Norafneeza Norazahar, Nur Azizah Arryanie Morshidi, Arshad Ahmad, Wijayanuddin Mohd Ali

Makara Journal of Technology

Performance-shaping factors (PSFs) are used to address the strengths and weaknesses of workers performing escape and evacuation activities. These PSFs are time, environmental factors as stressors, complexity of activities, experiences and training, interaction between workers and emergency equipment, workers’ physical conditions, and procedures. This paper presents a survey work on fitness for the duty of workers performing basic offshore survival and emergency response training. The training provides credible scenarios of escape and evacuation in case of an emergency of offshore installations in tropical waters. The survey is conducted among participants of the tropical basic offshore safety induction & emergency training …


Numerical Study Of Paraffin Wax Melting In A Cavity With A Gradient Of Hot Wall Inclination, Agus Dwi Korawan Aug 2020

Numerical Study Of Paraffin Wax Melting In A Cavity With A Gradient Of Hot Wall Inclination, Agus Dwi Korawan

Makara Journal of Technology

The melting of a phase change material (PCM) in a cavity with a gradient of hot wall inclination was simulated numerically using five models, namely, Model-A, Model-B, Model-C, Model-D, and Model-E with gradients of −2, −4, ∞, 4, and 2, respectively. The PCM was paraffin wax, which was melted using an enthalpy porosity technique with a pressure-based method. Model-A was found to be the best model. For the completion of the melting process, the models were assigned with the liquid fraction of 1. Model-A required the shortest time, followed by Model-B, Model-C, Model-E, and Model-D, respectively. Compared with Model-C, Model-A …


Effects Of Collision Damage On The Ultimate Strength Of Fpso Vessels, Muhammad Zubair Muis Alie, Dian Ramasari, Taufiqur Rachman, Ristiyanto Adiputra Apr 2020

Effects Of Collision Damage On The Ultimate Strength Of Fpso Vessels, Muhammad Zubair Muis Alie, Dian Ramasari, Taufiqur Rachman, Ristiyanto Adiputra

Makara Journal of Technology

Floating production storage offloading (FPSO) vessels are movable offshore structures. These structures are designed with large dimensions, and their decks are loaded with several types of equipment. During collision damage, the hull and deck parts loaded with equipment are severely affected. Therefore, the ultimate strength of FPSO vessels should be thoroughly checked and evaluated. The objective of the present study is to analyze the ultimate strength of FPSO vessels against collision damage characterized by hogging and sagging under longitudinal bending. The cross section of an FPSO vessel is modeled with elements composed of stiffened and unstiffened plates. The vessel length …


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 …


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 …


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 …


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 …


Fatigue Damage Assessment Of Reinforced Concrete Slabs Using Integrated Dynamic Testing And Simulation, Jamadin Adiza Apr 2020

Fatigue Damage Assessment Of Reinforced Concrete Slabs Using Integrated Dynamic Testing And Simulation, Jamadin Adiza

Student Works (2020-2029)

Assessment of existing fatigued structures is an important aspect of civil engineering infrastructure. This is critical in most loaded civil engineering structures such as bridges that are constantly subjected to dynamic loading, causing fatigue in the materials over time. Bridge deck slabs are one of the most structural elements susceptible to different cyclic loads, requiring regular checks for damage to fatigue. In order to understand the deterioration, fatigue carrying capacity and residual strength, the serviceability of the slab under the fatigue loads was not fully explored. Therefore, this research is designed to use vibration-based techniques to investigate the integrity of …


A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen Mar 2020

A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Self-healing asphalt, aimed to produce a sustainable asphalt pavement using green technology, has been studied in the past two decades. Technologies including encapsulated rejuvenator and induction heating have been proposed, demonstrated in the laboratory, and gradually evaluated in field application. This paper looks into the synergy effect of the above two technologies, where induction heating serves as the asphalt damage repair mechanism, requiring just 2 min heating time and encapsulated rejuvenator will replenish (rejuvenate) aged asphalt binder and reinstate bitumen’s healing ability. Moreover, the increased temperature from induction heating could in turn accelerate the diffusion process of rejuvenator into aged …


Solar Powered Parking Lot Lights, Jordyn Taylor Jan 2020

Solar Powered Parking Lot Lights, Jordyn Taylor

Sustainability Conference

Solar energy is a renewable resource growing exponentially around the country over the past few decades. Solar energy works through the use of photo-voltaic cells, which work to convert energy from sunlight into electricity. This is done within solar panels, which are then connected to batteries for energy storage to use as needed. As production has increased over past decades, the cost for solar panel hardware and installment has thus fallen to meet consumer need. While most common implementations include solar panels attached to one’s home or solar panel ‘fields’ for charging entire towns, there has been a steady rise …


Residential Thermal Storage And Cooling, Joao Marcelo Rocha Belmonte, Jacob Anderson, Andrew Clarke, Daphne Forester, Bianca Hardtke, Josh Hartman, Marc D. Compere Jan 2020

Residential Thermal Storage And Cooling, Joao Marcelo Rocha Belmonte, Jacob Anderson, Andrew Clarke, Daphne Forester, Bianca Hardtke, Josh Hartman, Marc D. Compere

Sustainability Conference

No abstract provided.


Comparision Of Fillet-Welded Base Plate Fatigue Design For Highway Support Structures With Laboratory Research Tests, William Shea Jan 2020

Comparision Of Fillet-Welded Base Plate Fatigue Design For Highway Support Structures With Laboratory Research Tests, William Shea

Williams Honors College, Honors Research Projects

There are many types of vertical structures along highways that serve unique purposes. These structures include traffic signs for directing, warning, or regulating traffic, luminaires for distributing and directing light, traffic signals supporting equipment such as traffic lights, and combination structures including any combination of the aforementioned structures. Highway support structures are typically fabricated from steel or aluminum and are designed to the guidelines and specifications of the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals. The structures are connected to a foundation by anchor bolts through a welded base plate. Often a cause …


The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1 Dec 2019

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …


Static Analysis Of Circular Plates Under Mechanical Loads, Harpreet Lalia Dec 2019

Static Analysis Of Circular Plates Under Mechanical Loads, Harpreet Lalia

Publications and Research

In this research statics analysis of circular plates is performed using SolidWorks.

Circular plates with different material properties, thickness to radius ratios, and boundary conditions under mechanical loads are modeled and analyzed in SolidWorks.

The results are obtained for deflections of circular plates under uniform and point loads.

A three-dimensional (3D) model of circular plates is first created in SolidWorks. Then the material properties, mechanical loads and boundary conditions are defined for the plate.

It is found deflection of plates is depended on magnitude of mechanical loads, geometrical parameters, boundary conditions and material properties. Responses of SolidWorks for deflections of …


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 …


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 …


Multiscale Modeling Of Fracture In Quasi-Brittle Materials Using Bifurcation Analysis And Element Elimination Method, Keyvan Zare Rami Dec 2019

Multiscale Modeling Of Fracture In Quasi-Brittle Materials Using Bifurcation Analysis And Element Elimination Method, Keyvan Zare Rami

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Analyzing the fracture of heterogeneous materials is a complex problem, due to the fact that the mechanical behavior of a heterogeneous material is strongly dependent on a variety of factors, such as its microstructure, the properties of each constituent, and interactions between them. Therefore, these factors must be effectively taken into account for accurate analysis, for which the multiscale method has been widely used. In this scheme, the computational homogenization method is used to obtain the effective macroscopic properties of a heterogeneous material based on the response of a Representative Volume Element (RVE). The growth of damage in an RVE …


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), …