Fabrication and characterisation of sandwich composites of glass fiber skin and polyurethane foamreinforced coconut coir fiber core

Kajian ini tertumpu kepada fabrikasi dan perincian ke atas komposit sandwic berpermukaan komposit gentian kaca dan berteras busa poliuretana yang diperkuat gentian sabut kelapa. Objektif utama kajian ini adalah mengkaji sifat – sifat fizikal dan mekanikal komposit sandwic dan menjelaskan kesan penggunaan gentian sabut kelapa keatas busa poliuretana dan panel komposit sandwic. Panel komposit sandwic terdiri dari dua bahagian, iaitu permukaan komposit gentian kaca yang dihasilkan melalui proses pengacuanan tekanan dan teras busa poliuretana yang dihasilkan melalui kaedah pengacuanan berputar. Kedua – dua bahagian ini disatukan menggunakan perekat epoksi pada tekanan 100 KPa. Gentian sabut kelapa digunakan untuk memperkuat busa poliuretana yang akan digunakan sebagai teras komposit sandwich. Peratusan berat gentian sabut kelapa yang digunakan adalah daripada 5%berat sehingga 20 %berat. Dari kajian yang dijalankan, didapati bahawa penggunaan gentian sabut kelapa telah meningkatkan prestasi sifat teras poliuretana dan komposit sandwic. Sifat – sifat fizikal dan mekanikal teras busa poliuretana dan komposit sandwic mencapai peningkatan optimum pada 5 %berat gentian sabut kelapa. Walaubagaimanapun sumbangan gentian sabut kelapa terhadap peningkatan prestasi hanya terhad pada 5 %berat kerana prestasi sifat mekanikal bahan menurun apabila melepasi komposisi ini. Ketumpatan komposit sandwic menurun sebanyak 32.41% pada komposisi 5 %berat gentian sabut kelapa yang mana mempunyai ketumpatan yang rendah dan menyumbang kepada penghasilan panel bahan yang ringan. Daya maksimum, tegasan ricih, dan modulus bagi komposit sandwic menunjukkan peningkatan masing – masing sebanyak 12.69%, 29.46% dan 12.97% pada peratusan gentian sabut kelapa 5 %berat. Ini menunjukkan bahawa sifat – sifat komposit sandwic dapat dipertingkatkan dengan peranan penguat didalam busa poliuretana yang menahan tegasan ricih secara melintang

Rigid Polyurethane Foam Reinforced Coconut Coir Fiber Properties

This research work studied the properties of composite foam panels. Coconut coir fibers were used as reinforcement in polyurethane (PU) foam in order to increase the properties of foam. This composite foam panels were fabricated by using polyurethane molded method. The polyurethane foam panels reinforced from 5 to 20wt% coconut coir were produced to investigate the physical and mechanical test via density test and three point bending test respectively. It was found that the density test results show the composite foam panel density decreases as fiber content increased. The composite foam panels with 15 wt% coconut coir fibers offered less density with average value of 76.78 kg/m3. Result from mechanical test shows that the flexural properties were increased at 5wt % of coconut coir fiber with average value of maximum force and shear stress at 88N and 60 KPa.  It was revealed that the coconut coir fibers at 5wt% significantly increased the physical and mechanical properties of composites foam panel

Fabrication, characterisation and properties of polysiloxane rice husk silica composites

The polysiloxane silica composites were fabricated and characterised as to elucidate the feasibility of casting (CA) and compression (CO) method. Besides, the contribution of rice husk silica (RHA SiO2) and crystalline silica (CS) in enhancing the composites properties were also investigated. Moreover, fabricated composites were applied in hand grinder as a vibration damper and the performance had been analysed. The important issues covered in this study were the contribution of RHA SiO2 instead of using CS as a filler and the investigation of most ideal parameter in improving thermal, physical, mechanical and vibration properties of composites. The polysiloxane composites were analysed and compared with various parameters i.e; composition of fillers (2wt% to 12wt%) and curing temperatures (room temperature (RT), 65 and 100˚C). Addition of 10wt% RHA SiO2 had found to contribute better performance compared to CS addition, accredited to RHA SiO2 density and surface morphology. As for the fabrication effects, CO method was found to offer composites with better tensile and vibration properties. However, as for the thermal behavior, CA method yielded composites with better thermal stability due to better filler distribution on surface of the composites. On the other hand, the increment of curing temperature does not show significant effect in improving thermal properties as the thermal stability were decreased due to interferences of curing network stability. However, the polysiloxane composites cured at 65˚C and 100˚C were found to offer better tensile and vibration properties. Throughout the observations, the maximum perfomance of thermal, tensile and vibration behavior for polysiloxane composites were achieved by addition of 10wt% RHA SiO2, fabricated using CO method and cured at 100˚C

The Influence of Electrophoretic Deposition (EPD) Parameters on SS430 Spinel Coated Characteristic

The interconnect that is applied with protective coating which is (MnCO)3O4 spinel coated stainless steel is crucial to enhance solid oxide fuel cell (SOFC) performance. In this research, commercial manganese cobalt (MnCO)3O4 is used by electrophoretic deposition (EPD) method as a protective layer on ferritic stainless steel. Elemental energy dispersive X-ray spectroscopy (EDS) was examined for the spinel coated interconnect (MnCO)3O4. Scanning Electron Microscope (SEM) examines the surface morphology and coating thickness. The EPD (MnCO)3O4 spinel coated interconnect is carried out with 30V to 50V with duration of coating from 20s in an aqueous suspension. The best covering parameter can be determined by observing the deposition morphology and density of the EPD at 40V and 45V for 20s. This article examines the impact of voltage deposition. The objectives of these study is to obtain the best parameter for the interconnect coating while experimenting with the voltage. 78.8μm with even and thick surface coating is the maximum deposition thickness achieved. Voltage deposition can therefore be concluded to affect the efficiency of the electrical conductivity of steel

Fabrication of high-quality electrode films for solid oxide fuel cell by screen printing: A review on important processing parameters

Summary Solid oxide fuel cell (SOFC) is known as the most efficient fuel cell, with an efficiency of 60% in converting fuel to electricity and up to 80% in fuel to energy conversion (including heat). A SOFC consists of three primary components, namely, anode, electrolyte and cathode. Given the demand for reducing the operating temperature below 800 C, not only thin electrolytes have become a necessity for their ability to reduce ohmic losses but also high-quality porous electrode (anode and cathode) films for their ability to accelerate electrochemical reactions with fuels. In this context, screen printing is known for its capability to form high-quality porous electrode films in a cost-effective manner. In addition, screen printing offers fabrication-related parameters that can be easily manipulated to produce different film qualities depending on the requirements which have been explored in various applications. However, screen printing is only utilised in SOFC application as a fabrication tool to produce electrode films, neglecting the effects of its fabrication-related parameters on electrode performance, as indicated by the limited number of related works. Despite limited resources, this study aims to review the fabrication-related parameters in producing SOFC electrodes through screen printing and their effects on electrochemical performance. The parameters at different stages (ie, prior, during and post printing), including ink formation, printing numbers and sintering, are extensively reviewed. To the best of our knowledge, this study is not only the first review that discusses the effects of screen-printing fabrication-related parameters on electrode potentials but also offers suggestions on future directions regarding these parameters towards the improvement of SOFC performance. Novelty Statement Among all thin-film fabrication methods, screen printing is known for its capability to form homogenous-porous SOFC electrode films; however, the processing parameters of screen printing at three primary stages (prior, during, and postprinting) are rarely explored. As such, the current paper highlights important parameters in screen printing, such as ink rheology, printing number, and sintering, to contribute to the understanding of the influence of these parameters on SOFC electrode film quality and their effects on electrochemical performance

Study of material characterization of samarium doped ceria-rice husk ash silica (SDC-RHASiO2)

Additional of metal oxide such as copper oxide, lithium oxide and iron oxide into ceria-based electrolyte had been commercialized to improve the performance of the ceria based material in microstructure modification. In this study, the effect of samarium doped ceria with the addition of rice husk ash silica on its characterization is described. Samarium doped ceria (SDC) with addition of 1.0 wt.% of rice husk ash silica (RHASiO2) was prepared by ball milling method. The SDC-RHASiO2 composite pellets were produced by uniaxial press and were sintered at 700°C. Material characterizations of SDC-RHASiO2 sample were identifying by X-ray diffraction (XRD) for crystalline structures, porosity test and scanning electron microscope (SEM) for surface morphology and microstructures. Based on XRD result obtained, it has been found that the result for SDC-RHASiO2 powder only showed the face-centered cubic lattice structure of (Sm.20Ce.80O1.90) without additional impurity phases. SEM micrographs indicated that the porosity percentage decreases when the RHASiO2 was added into SDC. This mixed material is believed could improve the structure as well as the performance of undoped SD

Effect of silica (SiO2) filler on thermal stability of polysiloxane composites

Thermal stability of composites are influenced by the types and properties of filler used. In this study Silica (SiO2) namely CS was used to improve the thermal stability of Polysiloxane (PoS) panel. The PoS/CS composites were fabricated by mixing PoS and CS with filler loading of 2wt% to 12 wt%. PoS/CS composites are then cast using close mold technique and cured at room temperature (RT), 65˚C and 100˚C. The CS were characterized for X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), and Fourier Transform Infrared (FTIR) technique. The thermal stability of PoS/CS composites were identified via Thermal Gravimetric Analysis (TGA). It was found that, CS improved the thermal stability of PoS by increased decomposition temperature and decreased relative mass loss percentage. CS as a filler, replaced and reduced the hydroxyl group in the composites panel to significantly improved the thermal stability. Hence, the good thermal stability of CS also helps to improve PoS composites thermal properties. The interference of hydroxyl crosslink during curing was also found to affect the thermal stability. Thus, the high temperature curing (65˚C and 100˚C) were indeed unstable due to disruption of cross link process and thus affect the filler dispersion and cause aggregations. PoS/CS/RT composites were found to show the stable and linear profile of thermal stability compare to PoS/CS/65˚C and PoS/CS/100 ˚C. Thus the thermal stability of polysiloxane had improved by using CS as a filler and cured at RT

The effect of pre-processing techniques and optimal parameters on BPNN for data classification

The architecture of artificial neural network (ANN) laid the foundation as a powerful technique in handling problems such as pattern recognition and data analysis. It’s data-driven, self-adaptive, and non-linear capabilities channel it for use in processing at high speed and ability to learn the solution to a problem from a set of examples. It has been adequately applied in areas such as medical, financial, economy, and engineering. Neural network training has been a dynamic area of research, with the Multi-Layer Perceptron (MLP) trained with back propagation (BP) mostly worked on by various researchers. However, this algorithm is prone to have difficulties such as local minimum which are caused by neuron saturation in the hidden layer. Most existing approaches modify the learning model in order to add a random factor to the model which can help to overcome the tendency to sink into local minima. However, the random perturbations of the search direction and various kinds of stochastic adjustment to the current set of weights are not effective in enabling a network to escape from local minimum within a reasonable number of iterations. In this research, a performance analysis based on different activation functions; gradient descent and gradient descent with momentum, for training the BP algorithm with pre-processing techniques was executed. The Min-Max, Z-Score, and Decimal Scaling Normalization pre-processing techniques were analyzed. Results generated from the simulations reveal that the pre-processing techniques greatly increased the ANN convergence with Z-Score producing the best performance on all datasets by reaching up to 97.99%, 95.41% and 96.36% accuracy

The Physical Characterisation of Coating via Electrophoretic Deposition (EPD) with Voltage and Duration Variables for Solid Oxide Fuel Cell Application - A Review

This review covers the basics of electrophoretic deposition techniques and its effect on the physical characterisation for solid oxide fuel cell application. On top of that, the characterisation of coating often affected by the variation of voltage. The higher the voltage, the more deposition weight obtained. The duration of deposition also crucial as it can influence the thickness of the coating layer.  The thickness and morphology of the coating layer were determined by using scanning electron microscopy (SEM). For its weight deposited, there were several techniques has been applied

Characteristics of BSCF–SDCC–Ag composite cathode powder for low-temperature solid oxide fuel cell

A fuel cell is a type of clean energy that may be utilised in various applications across numerous sectors. Solid oxide fuel cell (SOFC) has attracted considerable interest as a fuel cell type due to its excellent efficiency and durability. However, SOFC may encounter specific challenges because of its operating temperature, which is generally high. This circumstance might negatively affect the overall system performance. New materials that can work with SOFCs in the lowtemperature range (LT-SOFC) must be introduced to overcome the challenges. The milled barium strontium cobalt ferrite– samarium-doped ceria carbonate (BSCF-SDCC) composite cathode was introduced as a potential candidate for LT-SOFC material. Argentum (Ag) was added to the BSCF–SDCC composite cathode to act as a catalyst material for efficient performance. The characterisation of a BSCF–SDCC–Ag composite cathode was investigated under two properties, namely, chemical and physical. The X-ray diffraction results for phase identification showed that Ag addition exhibited compatibility with BSCF–SDCC composite cathode with no occurrence of impurities. The morphology and element observation showed that the composite cathode powder was well mixed, and all significant elements were uniformly and homogeneously distributed. The average percentage of porosity value was also obtained in the acceptable range (20%– 40%). Specifically, it ranged from 21.12% to 22.50%. Therefore, the findings of this study prove that the addition of Ag can improve the performance of the BSCF–SDCC composite cathode, which is in line with the function of Ag as a catalyst materia