Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia

This project intends to design and develop an extruder that can recycle the 3D printing wastes into a functional filament. The study aims to form the recycled filaments by using the product wastes from Acrylonitrile butadiene styrene (ABS) and Polylactic acid (PLA) types. Concept generation using a morphological chart and weighted matrix decision are utilised to build a 3D printer filament extruder. The process parameters for the extrusion process are determined using the Taguchi method to get the finest output of the recycled filament. The recycled filament is then used to fabricate the specimen with an open-source 3D printer. The relationship between the extrusion temperature and the filament thickness has been studied where the thickness is decreased as the temperature increased. The extruded from the recycled filament showed a low percentage of error in terms of filament’s thickness when compared with the thickness from commercial filament which is 1.75 mm. The observation and evaluation are done by comparing the output of filament and specimen between the recycled and virgin material. The result also shows some well-printed specimens printed with the recycled filaments that qualified in thickness when compared with virgin materials.

Using Topology Optimization (TO), this study analyses an existing Alcoa bearing bracket typically used on aircraft control surfaces, by redesigning the bracket to reduce weight while staying within the same target design envelope and meeting technical criteria. The methodology started with pre-analysis and topology optimization, where 15-5PH Steel, Ti6Al4V ELI-0406, and Ti-6Al-2Sn-4Zr-6Mo were compared, and one material was selected for the design process based on physical properties then TO process was performed to obtain a design with excellent strength to weight ratio, von Mises stress, displacement, mass, and factor of safety. Then build orientation optimization in Fusion 360 was conducted to obtain the minimum amount of support structure during AM. An Artificial Neural Network tool (ANN) was implemented to make the required geometric compensations on the bracket to control deformation arising due to the AM heating process. Then a conformity check was conducted to validate and to show the improvements achieved on the bracket after the ANN tool was implemented. Then the methodology finalizes with 3D printing of the bracket just to visualize the outcome of the TO process since the study’s focus was entirely on computer simulations and not experiments. The results selected a 40% volume retention using Ti-6Al-2Sn-4Zr-6Mo, also selected Rank 1 build orientation, and the ANN achieved 59.75% and 61.784% reduction in conformity error for Cartesian and Layered tetrahedral mesh respectively. Therefore, TO and AM have the potential to revolutionize industries, similarly, ANN proved to supplement the existing deformation prediction models.

In this study, 3D printed open-cell foam were produced and reconstructed from open-cell metal foam structure using a tomography scanning method and two different additive manufacturing technologies. The materials used in the 3D printing were nylon powder and plastic acid. The porous morphology and surface finish of the 3D printed foams were investigated using a microscope. The results showed that the surface finish and structure strength depend on the printing process, used material and foam size. This study found that laser-sintering technology would have smoother pores with lesser residue than stereolithographic. However, the ligaments of the small-size 3D printed foam were fragile and could be easily broken.

Additive manufacturing is a cost-effective and widely used process that is currently being researched by numerous researchers to maximize its potential for producing better products, particularly in the manufacturing sector. Nowadays, many types of waste such as plastic waste that is derived from petroleum-based polymer such as PET become threat to the environment due to their non degradable property. Thus, to overcome this concern recycling of waste material is one of the promising solutions. Recycled Polyethylene Terephthalate (rPET) as matrix are combine with sugar palm fiber (SPF) to develop 3D printing filament material. Currently, SPF is not being used to its full potential, particularly in additive manufacturing. SPF's appealing qualities, such as high durability and ease of processing, would be extremely advantageous in the field of additive manufacturing. Thorough understanding of SPF qualities and behaviour is required in order to fully employ SPF in the development of 3D printing filament. SPF works as a reinforcing agent, which is a crucial feature in improving the composites that are being developed in combination with the rPET. This natural fibre and recycled polymer matrix are expected to improve the thermostability, lightweight, strength, and transparency of the filament material while also contributing to waste reduction in the environment.

Laser Powder Bed Fusion (LPBF) uses rapid melting and solidification of Ti6Al4V powder layers to additively build the desired products. This has resulted in a steep temperature gradient and significant residual stress, which intensify the formation of porosity and flaws that deteriorate the mechanical performance. To overcome such issues, heat treatments such as hot isostatic pressing (HIP) are widely utilized. Although the use of HIP for LBPF parts is well applied, the significance of HIP in improving the components performance is under reported. Therefore, the purpose of this paper is to review the effect of HIP in improving the porosity and mechanical properties of LPBF-Ti6Al4V parts. HIP is found to be particularly effective in sealing pores and densifying Ti6Al4V components up to 99.6% which aids in resolving porosity concerns in LPBF products. This work suggests future research on the effects of HIP heating parameters on the mechanical and microstructure properties of LPBF-TI6Al4V components.

This study reports on the microstructure of SLM Ti6Al4V material after undergoing heat-treatment procedure as outlined by the SLM machine manufacturer. The heat-treatment follows a non-familiar route of single heating then associates with gradual cooling in steps, done in a fully controlled argon gas atmospheric environment. Comparison was done with microstructures obtained from previous studies using the well-known double heating and quenching treatment in producing a balance lamellar phase structure. Result of other’s hot isostatic pressing was also referred. It is shown that the obtained microstructure in this study is sufficiently having the balance lamellar phase, and comparable to that of expensive and sophisticated hot isostatic pressing’s result. This indicates that the SLM technology is at its mature level where the technology provider is preparing the process with a procedure that is reasonable to be applied, without the necessity to use the high-tech scientific procedure as being done for certain condition.

One of the major issues for additive manufacturing technologies is dimensional accuracy. The selective laser sintering (SLS) is a 3D printing technology that is able to produce infinite types of precise 3D printed objects. This aim of the research is to determine the effects of different compositions of virgin, reheated, and recycled polyamide-12 (PA-12) materials on dimension accuracy. The samples were additively manufactured using a SLS Farsoon 402P machine with a 70-W laser beam. Next, a calibrated machine block was used to measure and analyze the samples’ dimension accuracy in the X and Y axes using a ZEISS CONTURA G2 machine. Results showed that the recycled PA-12 material produced high accuracy with a mean value of 0.09% error in the X direction and 0.170% error in the Y direction.

In the new era of industrial revolution of 4.0, additive manufacturing (AM) technique gains attention from academia, researchers and industries. Fabrication of Polylactic Acid (PLA) honeycomb core using 3D printing technique was employed in this study via fused deposition modelling (FDM). Two types of sandwich composites were fabricated between carbon fibre face sheet with printed PLA core (C/PLA) and Nomex honeycomb core (C/NMX) via hand lay-up and vacuum bagging processes. Compression tests were conducted in the flatwise and edgewise directions according to the ASTM C365 and ASTM C364, respectively. It was found that the C/PLA exhibited higher on the compression stresses both in the flatwise and edgewise directions as compared to C/NMX. Tested sample of C/PLA displayed the flatwise and edgewise compression stresses of 25.7 and 125.0 MPa, while the tested sample of C/NMX exhibited the value of 7.9 and 12.6 MPa, respectively. In terms of compression strain, it was observed that C/PLA exhibited 31.5% higher than C/NMX in the flatwise direction.

Wire and arc additive manufacturing (WAAM) is one of the most suitable additive manufacturing (AM) technologies for producing large volume metallic components. However, one of the challenges for the WAAM process is poor part accuracy, which is emphasized by the bead geometry. In addition, deposition process parameters are the controlling factor for bead geometry. Aluminum Alloy ER5183 is chosen as a material due to its being lightweight and widely used in engineering structures for the transport sector. Therefore, the objective of this study is to investigate the effect of WAAM parameters on the bead width and height of three layers ER5183 deposits. WAAM process was conducted with a gas tungsten arc welding (GTAW) system. The deposition parameters were arc current (120–180 A), travel speed (25–30 cm/m), and wire feed rate (50–100 cm/m). Results show that welding current was the main controlling factor of the bead width and height. The high arc current (180 A) increases bead width, and the low arc current (120 A) increases the bead height. A set of optimization parameters for the bead width and height was then proposed.

Processing parameters and their energy density influence the performance of 3D parts manufactured by selective laser melting (SLM). Such performance covers the physical and mechanical properties such as surface roughness and microhardness. However, due to building direction, some 3D parts may have different surfaces or skins depending on their geometries. Although the processing parameters may have the dominant factor that influences the overall performance of a 3D part, each surface may have its own properties. It would be a practical approach to investigate the performance at different surfaces of a 3D part. In this work, the properties of surface roughness and microhardness at different skins of a Ti6Al4V cubic sample were investigated at various energy densities. Such sample was printed by different sets of parameters based on the Taguchi (L9) method at a building direction of 30°. Based on such direction, a cubic sample has several skins such as up-skin, core-skin and down-skin. Surface roughness and microhardness tests were conducted on such skins. It was found that the surface roughness (Ra) is in range of 10–20 µm for all samples. For microhardness, the obtained range was 350 HV–480 HV. It can be concluded that the suitable range of energy density to obtain smoother Ra and higher microhardness is 60–90 J/mm3, which does not differ much from the default setting of Ti6Al4V in SLM (69.44 J/mm3).

The part produced by the fused filament fabrication 3D printer in terms of tensile strength and surface roughness depends mainly on the printing parameters and the environmental printing conditions. In this paper, nitrogen gas had been allowed to flow inside the 3D printer chamber to exclude oxygen in the printing environment. Tensile and surface roughness tests were performed on samples of three different layer thicknesses (0.1 mm, 0.2 mm, and 0.3 mm) of ABS in FFF. The scanning electron microscope observed a strong bonding of microstructure for 0% oxygen, compared to 10% and 20%. A significant increase in tensile strength and surface roughness was found, possibly partially due to the prevention of oxidation processes. Reduced polymer surface degradation at relatively high printing temperatures demonstrates these effects. Printing in 3D under exclusion oxygen can be generated reasonably quickly by filling the printing chamber with nitrogen in potential applications to manufacturing FFF-printed parts with improved mechanical properties.

The focus of this research is to produce and design a lightweight brake caliper that would be produced using additive manufacturing. The use of additive manufacturing in producing brake calipers are not yet common. To design a lightweight brake caliper, lattice structures are integrated in the parts of the brake caliper models. Body Centered Cubic with z-strut and Face Centered Cubic with z-strut as they are both the most used strut-based lattice structures in the industries. Strut-based lattice structure does also possess the characteristics of higher yield strength and provides lower mass. The lattice structures were divided into 5 different solid fractions 10%, 15%, 20%, 25% and 30% with 11 sample models of the brake caliper including the solid-state model designed. Structural and thermal stress simulation were conducted, and the results data were analyzed and compared to choose the optimum model at the end of the research. Lattice structure Face Centered Cubic with z-strut with 25% of solid fraction has been chosen to be the optimum model after comparing the result data and fulfills all the requirements. In conclusion, the brake caliper’s mass decreased by 30% from 7.17 kg to 4.78 kg. In conclusion, the technology of integrating lattice structure inside a solid model for weight reduction in the field of additive manufacturing is the future for the automotive industry.

Agriculture waste were produced for more than 1 million tons annually in our country. The disposal of the waste by open burning tend to bring environmental pollution such as air pollution. Thus it is essential to identify an alternative usage of the agriculture waste. Agricultural waste can be considered as good source of silica and have potential for the large scale production and acid leaching is one of the proper route to extract silica. In this project, sugarcane bagasse which is one of the agriculture waste is use to extract silica via acid leaching method. The purpose of this research is to study the effect of the leaching parameters such as leaching time and acid concentration on the extraction of the silica. Hydrochloric acid (HCL) with concentration of 1.0M and 2.0M were used as extraction solvent of silica from sugarcane bagasse. Leaching time was varied at 30 min, 60 min and 90 min. Various samples were prepared and characterized using Scanning Electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersed x-ray (EDX) analysis. Based on the result of the analysis, it was proven that sugarcane bagasse can be considered as one of the alternative source in producing silica. The result indicates that the percentage of silica was increased from 57.10% to 99.0% when the leaching time increased from 30 to 90 min. Result of XRD analysis indicates that the extracted silica has an amorphous phase structure whilst the peak angle and intensity of the highest silica’s percentage were recorded at Bragg angle of 21.54° and intensity of 188.33 cps respectively.

This study aims to determine the effect of heating temperature on the hardness, compressive strength, and biodegradation rate of magnesium/Hydroxyapatite (HA)/Shellac. This research used Magnesium/HA/Shellac material which was mixed using a magnetic stirrer for 15 min. Materials mixed with a ratio of Magnesium/HA/shellac was 70/30 (% wt). The material was then compacted with a pressure of 20 bar for 15 min and then sintered at a temperature variation of 100, 150, 200, and 250 ℃. The testing phase for Magnesium/HA/Shellac includes hardness test, compressive strength test, degradation rate test and SEM-EDS observation. In the hardness test, the highest hardness was obtained at a temperature variation of 250 ℃ (62.44 HVN). The highest compressive strength was obtained at a temperature of 250 ℃ (47,06 MPa). Composites of Magnesium/HA/Shellac specimens with temperature variation of 250 ℃ had the lowest biodegradation rate of 0.57 cm/year. Observation of Scanning Electron Microscopy (SEM) show different crack sizes at each temperature variation. This biocomposite has the potential to be developed as a bone screw material.

Sudden changes in working temperature or thermal shock, such as quenching treatment, are very likely to be experienced by thermosetting epoxy resins when applied during their service life, which can degrade their performance. This article reports the change in tensile strength of thermoset epoxies subjected to quenching treatment. The material used is DGEBA resin which is cured with cycloaliphatic hardener with a ratio of resin and hardener of 2:1. The quenching treatment was carried out at the target temperature of 75 ℃, 100 ℃, 125 ℃, and 150 ℃ and the cooling medium of pure water at ambient temperature. The tensile test was performed on the specimens referring to the ASTM D638-14 standard. The result reveals that the tensile strength of epoxy resin has decreased significantly at the quenching temperature of 75 ℃, 100 ℃, and 125 ℃. The quenching target temperature of 150 ℃ produces tensile and elongation strengths commensurate with the properties of epoxy resins without quenching.

Water scarcity is a major issue in some part of the world today. In some countries, seawater desalination through membrane distillation (MD) technology has been used to overcome the issue. However, there are two major issues impeding the efficiency of MD process, namely vapour flux declination and membrane wetting. Recently, electrospun fibres have been proposed as an alternative approach in developing new membrane modules for MD process. In this regard, polyacrylonitrile (PAN) in the form of electrospun fibres is a popular choice due to its relative superiority characteristics such as hydrophobic surface, nanoscale fibre diameter, low thermal conductivity, and possessed strong mechanical strength. However, it is dependent on the fabrication technique, which has a significant impact on the characteristics of the final products. Electrospinning is the most efficient technique in the production of polymeric electrospun fibres using electric charges. Although electrospinning can often be seen as a straightforward process, it consists of several complex processing parameters that need to be optimised in order to get high-quality fibre membranes. In this review, a brief overview is presented on the electrospinning of PAN electrospun fibres, as well as the range of optimum processing parameters. This review also focuses on the characteristics of PAN electrospun fibres and recent fabrication methods in developing high-performance membrane modules.

This study is to determine the properties and characterization of carbon that produce from material after it undergoes heat treatment in inert condition. In this study the raw material used were waste oil palm trunk from palm oil plantation. Besides that, parameter such as different temperature and different heating rate ware also compared. The sample were heat treated at different temperature which is 500 ℃, 800 ℃ and 1000 ℃ and at different heating rate which is 5 ℃/min, 10 ℃/min and 20 ℃/min for 2-h soaking time. Raw OPT morphology shows smooth surface compared to morphology of heat-treated sample. The holes and swollen surface shows the development of porosity in the heat-treated oil palm trunk while FTIR spectrum showed by raw OPT, spectra of palm trunk that’s heat treated at 500 ℃ and 800 ℃ illustrate less absorption peak. This trend provides the evidence supporting that high temperature will produce better graphite carbon. It has the potential to reduce waste and improve environment quality.

This paper presents the effect of the dimple size and dimple density on the wear properties of mild steel AISI 1060 surface under constant loading. The dimple surface texture is produced using a ball-end-nose milling tool on a cross-sectioned surface of 32.5 mm cylindrical sample with a CNC milling method. The samples acted as the pin for pin-on-disk apparatus with constant loading setup. The dimples size is between 1 mm to 4 mm. The wear size on samples are analyzed using 3D laser confocal microscopy image analysis technique. The result shows that the highest wear rate occurred at the samples with the smallest dimple diameter of 1 mm, while no significant of wear observed on samples with the largest dimple size of 4 mm. It is expected that dimple size has a significant effect onto the contact between pin and surface, as the effect of friction reduced with the reduction of contact size.

The aim of this study is to investigate the characteristics of thermoplastic cassava starch (TPCS) composites containing sugarcane bagasse fiber (SBF) in the range of 0% until 30%. TPCS was modified by incorporating the sugarcane bagasse fiber integrated with glycerol and beeswax. The mixture is mixed using a high-speed dry mixer at 1200 rpm for 2 min then undergoes hot compression molding to form a sample of the new material. The composites were characterized for their moisture content, water absorption, and thickness swelling. In terms of water transport, the water absorption of the TPCS/BW-Sugarcane bagasse fiber composites were clearly reduced by the addition of sugarcane fiber. Meanwhile, the dimensional stability of the composites for the thickness swelling, 30% fiber content swelling the most. Overall, incorporating the sugarcane bagasse fiber into the thermoplastic cassava starch has improved the functional properties of this green material.

Magnetorheological elastomers (MRE) as intelligent materials are quite popularly used, both for indoor and outdoor applications that are often exposed to rain or sunlight depending on weather changes. In this case, the use of MRE material in outdoor use with exposure to freshwater and seawater needs further analysis. The analysis can then be used to evaluate the performance of the MRE. MRE specimens were molded in an isotropic state with vacuum treatment. Furthermore, the immersion treatment of the specimens was carried out for 6 weeks. In the 6-week immersion test, all specimens of material dissolution were dissolved, which was proven by a decrease in the percentage of absorption. The largest dissolution occurred in the 0%wt CIP heavy fraction specimen with seawater immersion treatment. In the hardness test of Durometer Shore A, both specimens of 0%wt CIP heavy fraction showed an increase in hardness, while in 70%wt CIP heavy fraction specimens, the opposite occurred. The greatest decrease occurred in specimens treated with freshwater immersion. The decrease in hardness can affect the stiffness of the material, resulting in a decrease in the damping function. The FTIR test showed that there were new peaks found in seawater immersion specimens.

The Resin Transfer Molding (RTM) process is one of the fundamental fabrication methods in composite material fields in aerospace and non-aerospace industries. It is a designation for a technology where, in general, a fiber preform is placed in a closed mold leaving a gap to allow the resin to be injected and impregnate the fibers. While, traditionally in aerospace manufacturing, autoclave which is known as an expensive process is utilized in the curing process of the parts. Thus, out-of-autoclave (OOA) manufacturing techniques is seeking to replace the autoclaving with a new process without compromising the quality parts. In this study, a newly developed RTM machine that has temperature and pressure controllers is used to produce hinge aircraft parts as a trial. This RTM machine has successfully injected a good quality of hinge part with a weight reduction of about 50% compares to the commercial. In conclusion, the RTM process has strong possibilities to develop and design for aircraft manufacturing parts to meet the future demand of less expensive aircraft part manufacturing.

Recently, porous nickel titanium (NiTi) made from nickel (Ni) and titanium hydride (TiH2) has been used for biomedical implants such as staples due to its pseudo-elastic and shape memory behaviour. Many methods are available to produce porous NiTi such as casting, metal injection moulding process, and additive manufacturing process. The metal injection moulding is one of the famous methods in producing porous NiTi. To obtain a good flowability during the injection process, it is important to find the ideal powder loading before conducting the injection moulding process. In this paper, the critical powder volume percentage (CPVP) and mixing process were discussed to determine the optimum powder loading for the feedstock before conducting the metal injection moulding process. From the calculation, the critical powder loadings for 50.0 at% Ni and 50.4 at% Ni were 69.6% and 71.4%, respectively. The ideal powder loading should be 2% to 5% from the critical powder loading. Therefore, the ideal powder loadings for 50.0 at% Ni was 65.5 and 67.5% vol%, while the ideal powder loadings for 50.4 at% Ni was 67.5 and 69.5 vol%.

The Alumina zirconia composite was proposed in biomedical application to overcome the low temperature degradation and poor toughness experience by zirconia and Alumina, respectively. The main issue in developing zirconia-Alumina composite is the homogeneous of the microstructure in the powder mixing. In these studies, Alumina zirconia composite will be prepared by using colloidal method with different vol% of zirconia contain ranging from 5% to 20%. The specimen was tested for its hardness and fracture toughness. Hardness tested by using micro indentation method and fracture toughness by measuring the dimension of the radial crack on the sample induced by Vickers. The specimen with 10% zirconia content yielded the maximum fracture threshold value of 5.0 MPa. m1/2.

Zirconia (ZrO2) powder from 1 weight percentage (wt%) to 5 wt% in comparison of wt% of Hydroxyapatite (HA) was added to form HA-ZrO2 composites to produce HA-ZrO2 composites that will exhibit desirable mechanical properties which can be useful in biomedical applications. Simple wet precipitation method was employed to produce HA and ZrO2. Low wt% ZrO2 of 1, 2, 3 and 5 wt% were used to prepare the composites which were pressureless sintered at 750 °C, 1050 °C and 1250 °C respectively for 2 h. Volume Fraction Porosity (VFP) was investigated and mechanical properties of Young’s modulus and microhardness were used for evaluation. It was found that composite that consist of 1 wt% ZrO2 sintered at 1250 °C showed the highest Young’s modulus and microhardness as both corresponds to the lowest VFP. The Young’s modulus and microhardness of this composite were found to be 100 GPa and 2.78 GPa respectively. This can be advantage in the field of orthopaedics in which implant materials have to withstand high stress.

The goal of this research was to fabricate an alumina-based cutting tool by powder metallurgy process. The process began with the compacting of spray dried alumina powders by using hydraulic hand press and Cold Isostatic Press in the form of round inserts. The alumina compacts were sintered at elevated temperature to form hard solidified structures. Machining trials were held with turning AISI 1045 cutting speeds between 200 m/min to 350 m/min with constant 0.15 mm/rev and 0.5 mm depth of cut. The results show that wear performance, the compacted alumina can machine AISI 1045 with a maximum tool life of 52 s at a cutting speed of 250 m/min. Because of the single particle packing without toughening, the sintered cutting tool exhibited brittle characteristics.

In this study, samples of Zirconia Toughened Alumina (ZTA) Composite with Y-TZP content between 0 to 20 vol% and 0.6 vol% copper oxide (CuO) were prepared and sintered via various sintering profiles of Two-Stage Sintering. The microstructural and mechanical properties such as bulk density, Vickers hardness, Young’s modulus and fracture toughness of these samples were determined to investigate the efficacy of the sintering profiles employed. Based on the data obtained, ZTA containing 10 vol% Y-TZP content and 0.6 vol% CuO with a heating rate of 10 ℃/min, T1 1450 ℃, T2 1350 ℃ and holding time of 6 h were found to be the optimum sintering profile. The sample’s grain size were reduced by >10% and mechanical properties were able to meet international standards such as ISO 6474 as the sample achieved full densification (>99%. T.D.), Vickers hardness, Young’s modulus and fracture toughness of 18.5 GPa, 409 GPa and 8.1 MPam1/2, respectively. This research could lead to development of ZTA composites with enhanced mechanical properties.

This study is to find the multi-response optimization of machining by finite element analysis simulation software using the grey relational analysis approach. The parameters selected are cutting speed, feed rate, and depth of cut towards the responses that are velocity, displacement, and temperature. Stainless steel was selected as workpiece and carbide material as cutting tool. L4 orthogonal array was implemented as an experimental design. In pre-processing the experimental result was normalized followed by determination optimization parameters from the highest value. It is found that optimum parameters for all responses are 150 m/min of the cutting speed at level 1, 0.5 mm of the depth of cut at level 1, and 0.3 mm/rev of the feed rate at level 1. Analysis result shows that the cutting speed is the significant factor that affects all responses followed by feed rate and depth of cut.

Natural fibres are derived from plants and animals, and they are the most efficient replacement for synthetic fibre. However, these fibres differ widely in physicochemical characteristics, hollow of lumen, uniformity, and degree of crystallinity, resulting in inconsistent mechanical property values. In this study, the tensile properties of a single Napier fibre were investigated according to ASTMD 3822-07. The test was performed using universal testing machines at a crosshead displacement rate of 1 mm/min. It revealed that the average tensile strength and modulus of a single Napier fibre were 23.47 MPa and 0.18 GPa, respectively. The Weibull modulus was determined to be 1.4261 with a Weibull parameter estimation error of 48%.

Persistent organic contaminants having two or more fused aromatic rings are called polycyclic aromatic hydrocarbons (PAHs). PAHs were produced from incomplete combustion of organic substances and cooking food at temperatures above 200 ℃. Despite the numerous studies that have highlighted the rising health danger caused by PAHs, research on activated carbon (AC) adsorption for PAH elimination has been limited. This review aims to discuss the best-recommended AC adsorption to remove PAHs. A selected number of the most prevalent AC adsorption with the highest removal efficiency of PAHs were reviewed. Summarily, this review concluded that the best method goes to AC adsorption using wheat straw pyrolyzed with limiting oxygen conditions at 800 ℃ for 6 h with 2 g/L dosages. The process yields 652 m2/g BET surface area and 0.634 m3/g total pore volume which has successfully removed 98.6% fluoranthene. It is interesting to note that the excellent removal efficiency is also due to the interaction mechanism between AC and PAHs that is hydrogen bonding, π – π interaction and van der Waals attraction.

Considerable interest in the natural fibre thermoplastic composite has been catalyst by their outstanding properties and as well as to reduce the environmental issue. Rubberwood polymer composite has been regarded as an excellent alternative for timber-based products. Rubberwood fibre is hydrophilic thus susceptible to moisture during application. Thus, this study aims to evaluate the effect of water immersion on the tensile properties of the rubberwood reinforced recycled polypropylene composite. The composite has good initial strength and modulus of 26.33 MPa and 1.69 GPa respectively. After 30 days of water immersion, the tensile strength and modulus of the composite decreased with moisture uptake, where their tensile strength and modulus significantly reduced to 12.19 MPa and 0.74 GPa respectively indicated the deleterious effect of the moisture onto their structural integrity. In contrast, their strain is increase after the water ageing process.

Polylactic Acid (PLA) are being utilized in various applications such as food packaging, biomaterial healthcare applications and 3D printing filament. Despite of all excellent properties of PLA, it has drawbacks which are low toughness, low in tensile elongation and high brittleness and low thermal characteristics. Hence, the aim of this paper is to review the effect of the addition bio-based plasticizer towards thermal properties of PLA. Many studies have been reported by researchers in producing a bio-based plasticizer originated from vegetable oils to replace the petroleum-based plasticizers which is harmful towards human and ecosystems. Four types of bio-based plasticizer were presented such as Epoxidized Karanja Oil (EKO), Epoxidized Rubber Seed Oil (EeRSO), Epoxidized Palm Oil (EPO) and a mixture of Epoxidized Palm Oil and Soybean Oil (EPSO). Blending ratio of bio-based plasticizer and PLA has affected the thermal properties which are glass transition temperature ( $$T_{g}$$ T g ), crystallization temperature ( $$T_{cc}$$ T cc ) and melting temperature ( $$T_{m}$$ T m ) are carried out. The findings from this review study shows that the highest reduction of $$T_{g}, T_{cc},$$ T g , T cc , and $$T_{m}$$ T m are at 10.13% for EKO, 12.2% for EPSO and 1.88% for EPSO. These results contribute significant improvement in flexibility and durability of PLA by mixing with bio-based plasticizer.

The influence of sintering temperature on properties of green glass ceramic composite (GCC) on various filler loadings was investigated. Experiment was conducted by using Design of Experiments (DOE) software. DOE applied was full factorial design which two factors and four levels. GCC was prepared using soda lime silicate glass (SLSG), spent bleach earth (SBE) and eggshell (ES). The results showed by increasing the sintering temperature, properties of the GCC will be improved. Sintering temperature was divided into 750, 800, 850, and, 900 ℃ at 2 ℃/min with holding time 1 h. The GCC was formed using hydraulic dry pressing for eggshell at 0, 5, 10 and, 15 wt. % as filler loading. This study is focused on physical properties of the sintered green GCC according to ASTM C373. At highest sintering temperature 900 ℃, apparent porosity was reduced from 17.95% to 12.97% and water absorption was reduced from 17.43% to 12.39%. The findings concluded that the suitable sintering temperature can be controlled for alternative materials for structural applications.

Unique combination of extraordinary properties has made graphene and its derivatives as a promising filler for composite materials in a wide range of applications. However, due to its weak dispersibility and agglomeration, the design of homogeneous graphene composite is very challenging as it may influence the final properties of the composite materials. One of the most crucial preliminary steps in the fabrication of graphene composite is the preparation of a stable and well-dispersed graphene dispersion. Many studies reported the usage of surfactant or dispersing agents which are mostly highly toxic and non-biodegradable. The current study discussed the dispersion of graphene oxide (GO) in distilled and deionized water at various dispersion times. The main aim was to investigate the effect of dispersion medium and sonication time on GO dispersibility. In this work, the GO nanoplatelets were sonicated using ultrasonic bath for a duration from one (1) to four (4) hours in distilled and deionized water. Observations immediately after sonication and after 24-h were recorded respectively. Results show that the GO dispersions in deionized water was comparably more dispersed than GO in distilled water. In addition, the observation after 24 h also shows long-term stability of all GO in deionized water. The darker color of dispersion for GO in deionized water as compared to GO in distilled water indicates lesser agglomeration and more dispersibility of the nanoplatelets. The outcome of this work contributed to the facile and environmentally friendly method of the GO dispersion and worthy to be used for the preparation of homogeneous graphene composite specifically for graphene composite coating using electrodeposition method.

Pineapple leaf (PALF) and kenaf fibre has wide potential to be used as a reinforcement material in polymer composites for different applications. Hybrid composites of natural fibre is one of the favorable method in order to improves the mechanical properties of the composites. This research investigates the mechanical and morphological properties of PLAF/kenaf fibre reinforced vinyl ester hybrid composites. The fibre was treated with alkalization and samples were prepared using hand lay-up method. Tensile and flexural test were conducted to determine mechanical properties of the hybrid composite. From the obtained results, treated fibre successfully enhanced the mechanical properties of vinyl ester hybrid composite. The morphological examination of neat polymer, treated and untreated fibre composite-reinforced vinyl esters were carried out to anlyse the morphological properties. Treated fibre composites showed less fibre pull-out compared to untreated fibre composite. The observation indicates the improvement of interfacial bonding between fibre and polymer which improved the tensile and flexural properties of the composites. Combination of PALF and kenaf fibre gives outstanding properties to mechanical properties of the composites.

The existed moveable fence barrier at toll highway exit Ayer Keroh, Melaka, Malaysia is a ground reinforced cable wire barrier, which is used to mitigate the vehicle impact at the highway area from any errant vehicles. There are few liabilities with the existed design of the barrier that needs to be improved. The analysis included for the barrier inspection were structural analysis, impact force analysis and wind force analysis. The load given considered the vehicle’s weight and speed. The Finite Element Analysis, FEA was applied for this analysis. The design lies under the limit value of 10 kN impact load. Under this condition, the predicted total deformation, equivalent stress and the factor of safety were predicted at 5.176 × 10−4 m, 3.241 × 107 Pa and 2.6933. The small value of deformation was due to the material that absorb the vehicle’s impact and also the small ductility of steel. The factor of safety bigger than 2 also showed the acceptance of the fence design strength for the intended load.

Landing gear mechanism trainer is an important and useful equipment for aircraft module training. It is essential for trainees to comprehend the theory as well as practical training related to maintenance of the landing gear system. The device can also be used in the lecture or during ground school course training. In this work, the design of low-cost aircraft landing gear system for training purpose is proposed. Market feasibility study is first conducted, and the design parameters of the proposed hydraulic landing gear trainer system is based on the survey results. The landing gear system is equipped with retractable main and nose landing gear. By using engineering methods such as House of Quality (HoQ), and Morphological Method, three conceptual designs of hydraulic landing gear trainer system were proposed. The final design was selected by using the engineering approach which is Weighted Decision Matrix (WDM). The engineering drawing of the final design was made using CATIA software. Finite Element Analysis (FEA) was performed focusing on the landing gear structure and the main body frame. The results show that the proposed design is able to meet the minimum structure required with factor of safety 1.5.

Five product criteria are being considered in this paper for the natural fiber composites selection for the drone frame structures. The weightage criteria were calculated by using the analytic hierarchy process (AHP) method. The highest weightage of the criteria is the performance with the value of 0.337 followed by environmental 0.311, cost 0.193, weight 0.086, and size 0.073. Then, by using the same method by considering the most important criteria which is the performance, three natural fiber composite filaments were chosen where poly-lactic acid (PLA) reinforced with 6.3% Jute (PLA/Jute), polypropylene (PP) reinforced with 30% Harakeke (PP/Harakeke), and PP reinforced with 30% Hemp (PP/Hemp) were compared. The highest-ranking for the natural fiber composites filament is PLA/Jute with the value of 0.417 for the tensile strength and 0.478 for the modulus followed by PP/Harakeke and PP/Hemp. Finally, the best natural fiber composite filament for the drone structures is PLA/Jute with the value of 0.449 compared to the other two filaments. This research shows that AHP can assist engineers and researchers in deciding the best natural fiber composite filaments with the structured and well-defined goal.

Surface quality of machined surface such as the surface roughness play important role in determining the final part of the products. Thus, selection of the cutting parameters and cutting tool geometry during machining are crucial to determine progression of the tool wear as well as the surface quality of the machined surface. The objective of this paper is to optimize the cutting-edge radius (CER) of the cutting tools and the width of cut during machining of DAC 55 steel. In this study, side milling of DAC 55 steel was carried out with a constant cutting speed of 2800 RPM and feed rate of 350 mm/min. Width of cut of 0.1, 0.6 and 1.2 mm and CER of 10, 20 and 30 µm were implemented to observe the effect of both parameters on surface roughness and tool wear. The influence of cutting parameters combination were evaluated using Full factorial method. From the results, it was observed that the width of cut is the most significant effect on improving the surface roughness quality compared with CER. It was found that by implementing 30 µm CER and 0.1 width of cut resulting in optimum quality of surface finish. For the cutting tool wear, it found that the cutting tool edge radius 30 µm and width of cut 0.1 mm experienced less wear when they reached the 4400 mm of distance travelled.

This study was performed at the local company where the use of fiber laser is applied in cutting sheet metal. The company faces a problem to identify the optimum laser parameters for cutting varies thickness of sheet metal. This study aims to evaluate the best combination of parameters for producing quality machining result by using statistical method via JMP software. Laser power and cutting speed were found the most influence parameters in the formation of burrs. Thus, the best combination between these parameters should be considered.

Stirling engine as the prime mover is again the focus of development because it has many advantages, including being able to operate with various types of heat sources. Because of these advantages, it can be used for applications in micro-scale combined heat and power systems (mCHP) for household applications. The heat source for the Stirling engine is obtained from the combustion of LPG gas. This study aims to analyze the performance of the 2nd generation Stirling engine with an ideal cycle thermodynamic analysis approach. This research uses a gamma-type Stirling engine with air as the working fluid and the preload pressure of the working gas is the atmospheric pressure. This engine has a maximum volume of 0.000201 m3. The results showed that the average thermal efficiency was 24.6%. The average engine speed and power produced are 415 rpm and 37.9 W. The average maximum pressure produced during the testing process is 2.446 bar.

This paper presents a study on the characteristics of indoor solar simulator which include the spectral match and spatial non-uniformity assessment. A halogen based solar simulator from Universiti Teknikal Malaysia Melaka (UTeM) had been setup at one of its laboratories named as Applied Solar Energy Laboratory (ASEL). Like other solar simulator, several tests need to be done towards this ASEL’s solar simulator to ensure its compliance to the standard set for solar simulator. The performance of the solar simulator was evaluated based on International Standard of IEC 60904-9, which involve the spectral match, spatial non-uniformity and temporal instability of the irradiance. The objective of this research was set to identify the characteristics of spectral match and spatial non-uniformity. The results show that ASEL’s solar simulator managed to produce spectral match value of 0.40 and 1.46 at a wavelength range of 400–500 nm and 500–600 nm respectively. Meanwhile, through the mapping method, it reveals that this solar simulator able to produce a good percentage of spatial non-uniformity which is up to 8.42% across the tested area of 104 cm × 80 cm.

FDM filament is mainly made of polymers, specifically PP, ABS, and PLA. Humans leave many 3D printed objects utilising FDM filament despite their good state. So recycling FDM filament, especially polypropylene waste, helps reduce landfill dumping. Using the CES-Edupack Software, this study will show a simple approach for material selection and life cycle analysis of recycling polypropylene with wood dust as reinforcement. This method assesses a product’s environmental impact throughout its life cycle, from raw material extraction through final disposal. The project collects data on energy use, carbon dioxide emissions, toxicity, recycling, and sustainability. As a result, suggesting recycling polypropylene with bio-composite as reinforced materials allowed a user to form conclusions regarding a sustainable recycling method for plastic waste and it may become an alternative strategy for managing plastic waste.

Due to the challenges of the IR 4.0 era and the Covid-19 pandemic at the same time, this paper provides a brief review of the published studies predominantly on biodiesel storage tank materials and followed by the Internet of Things (IoT) system as an alternative monitoring method in biodiesel industries. The suitability of storage material for a longer storage duration due to lower oil demands amidst this pandemic becomes a major concern. In this paper, two important parameters: kinematic viscosity and flashpoint in consideration of storage tank materials relating to surrounding conditions and biofuel blends were discussed. It was found that the degradation of fuel in plastic and glass storage tanks is significant for outdoor storage. Over time, the kinematic viscosity of biodiesel shows an increasing trend meanwhile the flashpoint is in decreasing trend or almost constant. However, these physical properties show very limited changes when stored at an ambient temperature. On another note, IoT systems to date are mostly used to detect fuel theft, fuel consumption, fuel impurities, and fuel tank level but are yet to be used to observe the fuel quality under a longer storage period, more than 6 months. IoT solution with suitable embedded sensors has potential to become the advance solution for remote biodiesel quality monitoring, reducing the need for manpower and interaction. This review paper provides necessary information for further investigations on biodiesel stability, storage material, and monitoring advancement systems.

Energy sources from oil and gas will eventually run out and run out, so it is necessary to look for other energy sources. The purpose of this research is to obtain a source of energy obtained from solar heat which is trapped in a prototype device. The method used is to use a Peltier device that functions as a tool to convert solar heat into electrical energy. The result of this research is a prototype that is connected in series to generate electricity.

A car spoiler can alter the aerodynamic forces acting on the car while driving. The benefits of it include manipulating the drag force and lift force. The fuel consumption can decrease and the car becomes more stable after attaching the spoiler. Here, a spoiler that could actively assume three configurations was studied. This could be an automatic spoiler that can morph into three shapes based on situations such as to decrease the fuel consumption for economic driving and to increase car stability while cornering or in high-performance handling of the car. The basic shapes of the spoiler were drawn using the SolidWorks package. The spoiler comprises of a 290 mm main plane and a 120 mm flap. The target design has no gap between main plane and the trailing-edge flap. Next, the spoiler design from SolidWorks is imported to ANSYS Fluent package, where simulations and analysis on the spoiler were executed to get the coefficients of drag and lift. In the end, the simulation shows that the active spoiler without the gap can achieve higher down force when fully deployed at 40° and it shows, at least, a slightly higher drag force as well.

The solar-assisted heat pump system consists of an evacuated tube solar collector, compressor, dual condensers, fan coil, expansion valve, and evaporator. Two basic functions of the heat pump are to heat the dryer and dehumidify the air as well as recirculate it and the solar drying assisted by the heat pump will achieve high efficiencies. The effectiveness of the heat pump is denoted through its COP, described as the ratio of whole heat delivered by using the heat pump to the quantity of electrical energy needed in order to run the heat pump. With the addition of the dual condensers, the temperature of the dryer was 60 ℃ with a relative humidity of 70% and the COP of the system was 5.546 under the Malaysia climate conditions.

Alcohol is a renewable energy source that may be used to power an internal combustion engine and generate electricity via a generator set. As a result, the goal of this research is to investigate at the performance of small-scale generator sets powered by alcohol. The fuel utilized was an alcohol combination of 86.52% methanol and 9.97% ethanol. The test findings revealed that the higher the engine rotation, the greater the engine power. The resultant power rose from 733 W to 2000 W, or by 2.7 times, when the motor rotated at 2100–2800 rpm. Specific fuel consumption drops dramatically and hits a minimum at around 2800 rpm.

Hydroponics is a recent method of agricultural production in which plants are grown in a soilless media. Various issues have been widely discussed in the hydroponic system, one of which is the hydroponic system’s power supply. Typically, it is powered by conventional electrical energy and should be operated at all times. The objective of this project is to integrate a sustainable energy source into a small-scale hydroponic system and also evaluate the return on investment (ROI) from the installation of the Off-Grid Photovoltaic (OGPV) system. This system is comprised of a 25 W photovoltaic panel and 9 Ah batteries to provide energy storage for the DC water pump and monitoring system, which utilize around 53.64 Wh/day. The investment into the OGPV system can achieve the return in 2 years and 9 months via utility bill cost reduction.

This article describes the performance evaluation of an electronic wedge brake (EWB) in a vehicle braking system. Simulation and experimental research were utilized as assessment methodologies. The vehicle braking system was simulated utilizing a verified quarter vehicle traction model with a validated EWB model as the brake actuator. To investigate the efficacy of the EWB, a dynamic test, meaning sudden braking at constant speeds of 40 and 60 km/h, was employed, and the results of simulation and experiment were compared and evaluated. Several aspects of the vehicle’s performance are examined, including its vehicle speed, wheel speed, longitudinal slide, and stopping distance. The study’s findings indicate that the proposed EWB braking system may provide excellent performance and be recommended for usage in actual automobile brake systems.

The industrial revolution IR4.0 era have driven many states of the art technologies to be introduced especially in the automotive industry. The rapid development of automotive industries in Europe have created wide industry gap between European Union (EU) and developing countries such as in South-East Asia (SEA). Indulging this situation, FH Joanneum, Austria together with European partners from FH Aachen, Germany and Politecnico Di Torino, Italy is taking initiative to close the gap utilizing the Erasmus+ United grant from EU. A consortium was founded to engage with automotive technology transfer using the European framework to Malaysian, Indonesian and Thailand Higher Education Institutions (HEI) as well as automotive industries. This could be achieved by establishing Engineering Knowledge Transfer Unit (EKTU) in respective SEA institutions guided by the industry partners in their respective countries. This EKTU could offer updated, innovative, and high-quality training courses to increase graduate’s employability in higher education institutions and strengthen relations between HEI and the wider economic and social environment by addressing University-industry cooperation which is the regional priority for Asia. It is expected that, the Capacity Building Initiative would improve the quality of higher education and enhancing its relevance for the labor market and society in the SEA partners. The outcome of this project would greatly benefit the partners in strong and complementary partnership targeting the automotive industry and enhanced larger scale international cooperation between the European and SEA partners. It would also prepare the SEA HEI in sustainable partnership with Automotive industry in the region as a mean of income generation in the future.

Savonius turbine is a type of drag turbine which has a simple construction design and good starting torque. However, this turbine still has low efficiency. This research was conducted to determine the effect of adding end-length of blades on the performance of the Savonius water turbine. The research uses the vertical fall fluid method with 3 discharge conditions at each addition of a deflector variation that is used to direct the focus of the fluid flow, so as to increase the torque working moment. Savonius water turbine performance is analyzed through Power Output. There are 4 variations of the Savonius turbine which were tested experimentally, namely the ratio value of l and r = 0; 0.2; 0.3; and 0.4. The maximum electric power is achieved with a variation of l/r 0.2 at a 20° deflector with a value of 11.51 W on water discharge of 1621.62 lpm.

The flow of rivers and lakes that flow throughout the year has the potential for developing water energy in the world. Dams to make heads are needed as a hydroelectric power plant that can cause environmental and ecological changes, disrupt river flow and even local population migration. The application of microhydro power plants is one of the efforts to overcome this problem. Gravitational Water Vortex Turbine (GWVT) is a relatively new technology in the field of microhydro power generation and is still in the process of being developed to obtain maximum turbine power values. The blade shape research has been carried out using the experimental method in this study. The research was conducted using a water tunnel with a cone type basin to create a water vortex with three variations of water discharge. Design and testing of prototype L-type runners with variations of three blade angles; 75°, 90°, 105°, the inclination of the blade to the vertical axis of 60°, and the number of blades 5 have been completed in this study. The results showed that the L runner with an blade arc angle of 90° produced the highest turbine power followed by a blade angle of 75° and 105°.

Indonesia is a tropical country that has high rainfall. The potential of water is used to drive the Savonius water turbine in high-rise buildings with low head. Turbine can rotate at low fluid flow velocity but still low efficiency. This study aims to determine the effect of the number of blades on the output power produced by using a deflector. Experimental research using 20° and 30° deflectors with variations in the number of blades 5, 7, 9, 11. To determine the performance of the turbine analyzed using data Power Output, Coefficient Of Power and Tip Speed Ratio. The 20° deflector produces the best performance on a 7 blades turbine at discharge of 27.03 L/s with an electrical power of 13.29 W, while the Coefficient of Power is 0.079 with a TSR value of 0.694 at a discharge of 9.29 L/s. The 30° deflector produces the best performance on a 7 blades turbine at discharge of 21.66 L/s with an electric power of 10.55 W, while the Coefficient of Power is 0.087 with a TSR value of 1,600 at a discharge of 7.67 L/s. The 7 blades turbine produce the best performance in both variations deflector 20° and 30°.

Bubble column reactors (BCR) are multiphase reactors used in the production of biodiesel. A bubble column reactor can withstand a higher temperature and provide higher efficiency in the process. During the transesterification process in the bubble column reactor, the bubble will be produced and will affect the bubble column reactor performance in biodiesel production. This study aimed to determine the effects of various reaction temperature and inlet velocity in a bubble column reactor on the sizes of the bubble for the transesterification reaction in the production of biodiesel. Different design of perforated plate is also used to find the effects of bubble size. The temperature used are 523 K, 543 K and 563 K and the inlet velocity are 2 m/s, 4 m/s and 6 m/s, respectively. Design and simulation of BCR were performed using SOLIDWORK 2018 ANSYS Fluent. The results obtained show that a drastic changing of gas holdup was found for design A at 563 K and 6 m/s inlet velocity. On the other hand, high circulation pattern occurred on the inlet, outlet, holes of perforated plate, and wall of reactor.

Having well-defined control strategies for fuel cells, that can efficiently detect errors and take corrective action is critically important for safety in all applications, and especially so in aviation. The algorithms not only ensure operator safety by monitoring the fuel cell and connected components, but also contribute to extending the health of the fuel cell, its durability and safe operation over its lifetime. While sensors are used to provide peripheral data surrounding the fuel cell, the internal states of the fuel cell cannot be directly measured. To overcome this restriction, Kalman Filter has been implemented as an internal state observer. Other safety conditions are evaluated using real-time data from every connected sensor and corrective actions automatically take place to ensure safety. The algorithms discussed in this paper have been validated thorough Model-in-the-Loop (MiL) tests as well as practical validation at a dedicated test bench.

Synovial fluid (SF) represents a clear and sticky fluid, which could be released by the synovial membrane and acts as a lubricant for joints and tendons. The purpose of this study was to analyze the hydrodynamic pressure of this lubricant in the artificial hip joint during bowing, in that the Moslem acts prayer positions. Computational Fluid Dynamics (CFD) coupled with Fluid-Structure Interaction (FSI) methods-based simulation was employed in the study for examining the lubrication fluid performance. In this case, the SF fluid was modeled as non-Newtonian fluids, whereas Newtonian fluids are modeled as water. The non-Newtonian fluid model was used as cross modeling. The material from the acetabular cup, outer liner, femoral head, and stem is Stainless Steel. While the inner liner is Polyethylene. Lubrication occurs in the elastohydrodynamic regime. The result is the hydrodynamic pressure in non-Newtonian fluids (SF) is higher than in Newtonian fluids significantly.

Muscular strain and fatigue are always associated with prolonged standing and causing an increased risk of musculoskeletal disorders among surgeons. Lack of ergonomic awareness and aging in the population also further increases the risk of musculoskeletal disorders. This paper analysed the design of a walkable chair that straps to surgeons’ lower extremities to support their weight while performing surgical operations in a half-sitting posture through finite element analysis. Nonlinear static analysis is carried out to analyse the design by using Solidworks. Design optimisation is also implemented to ensure the walkable chair is functional under a desired applied load. In this analysis, the 6061-T6 aluminium alloy was selected as the main material due to its high strength-to-weight ratio and excellent corrosion resistance. The result showed 61.54 MPa of maximum von Mises stress located at the joint support component after the walkable chair is subjected to 50 kg of applied load per extremity. While other components bear lesser von Mises stress compared to joint support. Based on the result, a 4.47 value factor of safety is calculated, and this indicated the structural design can sustain four times the maximum von Mises stress without fail.

This study discusses the Eddy Current Brake (ECB) system with the application of electromagnets. Half-circle slots will be applied on the surface of the ECB conductor to further investigate its effect on the resulting torque value. This study uses the Finite Element Method (FEM) in the simulation process of the ECB system with variations in the depth of the half circle slots of 0.5, 0.6, 0.7, 0.8, and 0.9 mm. The results of the study showed that the highest braking torque value was 15.139 Nm produced by slot depth variations of 0.7 mm at a rotary speed of 450 rpm and the smallest torque was 8.557 Nm, produced by a variation of 0.5 mm in slot depth at 150 rpm. The results also indicate that there is an effect of the depth of the half circle slot on the braking torque value produced by the ECB system, although it is not significant.

Brake is a vital component of a vehicle, particularly for motor vehicles. One of the braking used the principle of Eddy Current Brake (ECB) by utilizing electromagnetic. ECB is a braking technology without direct contact by utilizing eddy currents. ECB performance can be influenced by several factors, one of them is the surface shape of the disc conductor. Using finite element simulation, this research examines the impact of increasing the number of slot half-circles on the performance of the ECB with the number of slot changes. Variations number of slots that used are 6, 8, 10, and 12 slots. The result of this study obtained the best braking torque value in the variation with the number of 10 slots at a rotational speed of 450 rpm with a 15,930 Nm torque value. The addition slots of the number of half-circle types have a less significant effect on the torque from the simulation.

Eddy Current Brake (ECB) is an innovation in the braking system by utilizing the eddy current generated by induction when the rotor rotates due to the magnetic field generated by the stator. The development of the ECB braking system is needed to provide a better design overview from existing research. This study discusses the effect resulting from the use of half circle type slots on the surface of the disc conductor on the braking torque generated in light vehicles. This research uses Finite Element Method (FEM) in the ECB modeling process. The variations used are the width of the half circle type slots of 2, 3, 4, 5, 6, 8 and 10 mm. The results obtained from this study are the greatest braking torque value occurs in the 5 mm slot width in each rotational speed variation. The results of the study show that there is an effect of changing the width of the half circle type slot on the braking torque produced by the ECB braking system but the resulting value is not significant.

By utilizing additional smart dampening devices, semi-active vibration control is considered a powerful way of lowering the dynamic reactions of structures. The task is carried out by making diagrams in Simulink and the Matlab program. This is used to determine the natural frequency of a building and the vibration response that occurs in the building. In addition, the shape mode of a building model that will be tested with the application of damping devices can also be known. In this paper, simulation by Simulink will be elaborate to observe the effect of damping and stiffness constants on the vibration properties of a seismic building to evaluate shape mode and vibration response of structure model. The building simulation is a model of a four-story building. The response from the fourth floor achieved the highest peak displacement at 3.7 cm and reached stability with the longest time of 550 ms.

This study aimed to analyze the effect of inlet temperature and airflow direction variation of a spray dryer on the product’s water content and minimum droplet temperature using the means of computational fluid dynamics (CFD). The airflow direction types were mixed and co-current. The k-ω SST and standard k-ε models were used to simulate the flow, and the Eulerian-Lagrangian approach was used to predict the motion of particles. The simulation results showed that water content decreased as temperature increased for both airflow directions and vice versa for the minimum droplet temperature. A mixed flow spray dryer produced the lowest water content (0%) product with droplets diameter of 10 µm and 30 µm and an inlet temperature of 180 ℃. The lowest minimum droplet temperature (32.73 ℃) occurred in the mixed flow spray dryer with an inlet temperature of 100 ℃.

Stretchable conductive ink has been widely investigated to be used in the fabrication of stretchable electrical devices. Experimentation methods to test the mechanical and electrical behaviors of the stretchable conductive ink composite are widely applied, however, not much of computational method has been used to further validate the results. In this paper, finite element analysis method has been employed to investigate the relationship between the stress distribution of the stretchable conductive ink with the highest strain obtained. This research validates the past experimentation works of different patterns of stretchable conductive ink for its stretchability and electrical performance. The average stress distribution of the stretchable conductive ink played a significant role in the determination of its electrical performance, rather than the localization of high Von Mises stress (VMS) at certain locations within the stretchable conductive ink pattern. The lower average stress distribution contributed to a better stretchability which is indicated by a higher strain rate prior to electrical conductivity.

During the years 2011–2012, WHO recorded that the mortality of senior citizens caused by bone fractures globally reached 5.6 million, which lowers the quality of life. Bone grafting is a known method that is used for solving bone defects, but it is costly. Furthermore, the disease transmission and the immune response increase the significant danger to the elderly's health. One of the renowned tissue engineering products is the bone scaffold. Hydroxyapatite (HAp) with the molecular formula Ca10(PO4)6(OH)2 is frequently used for this application. It has properties similar to bone tissue in humans, however the mechanical stiffness and strength are too high. To modify mechanical properties, biomaterials Hydroxyapatite should lower its stiffness to match the mechanical strength of the surrounding bone to prevent stress shielding and it should support bone tissue regeneration. Pore distribution and size in hydroxyapatite coincide with the function of the porous scaffold. The effects of porous media with variations in model of dense (HAp), centralized porosity, and homogeneous porosity were studied using simulation. In response to compressive stress (MPa) and displacement (mm) of the femur bone, the percentages of porosity in each porous model were 30%, 40%, 50%, 60%, 70%, 80%, and 90%, and pore size was 300 m. The model that results is close to and suitable for the application as a bone implant is the homogeneous porosity bone scaffold model with variations of pore size of 300 µm and percentage of 90% porosity. The compressive stress value and displacement value of the model are, respectively, 32.163 MPa and 0.000831mm.

Indonesia is one of the largest exporting countries for palm oil production globally. In 2018, the country had a plantation area of 14.3 Million Ha, with palm Oil Production (Crude Palm Oil) of 40.5 million tons. It generates large amounts of waste as Palm Oil Mill Effluent (POME), empty fluid bunch (EFB), fiber, and shells. POME has an organic content and contains carbohydrates, lipids, and proteins. Generally, the POME by-products from palm oil mills in North Sumatra Province are processed using an Anaerobic treatment before release to the environment. This method still disposes of pond waste. It produces CH4 and bad smells into the environment. This research uses Aspen plus software to simulate POME becoming bioethanol renewable energy and reduce environmental pollution caused by POME. Bioethanol production is processed biologically by fermentation. Based on the analysis of simulation, 10 L tons/day POME can produce main products 0.187 L Ton/day bioethanol with the content of up to 41.95% C2H5OH, 9.29% H2O, and 48.76% CO2, and by-products 9.823 L Ton/day with the content 99.7% H2O.

The natural frequency of a structure can be highly affected by the condition of damage presented in the structure. This study aims to diversify the past studies by conducting a theoretical analysis of a thin plate with three parallel horizontal cracks. First, Kirchoff's classical plate theory was used to obtain the governing equation of a thin plate. Next, Galerkin's method was employed on the governing equation and Berger formulation for transverse deflection. The governing equation was then finalized for the CCSS boundary condition to obtain the fundamental natural frequency. Results from the comparison show that a good agreement can be obtained with a maximum percentage error of 0.60%. Later, the fundamental natural frequency for a single crack at upper, middle and lower and all three cracks was computed. A decreasing trend can be observed with the lowest natural frequency exhibited when all three cracks are presented due to stiffness loss. This study supplements the existing theoretical analysis on a thin plate for three parallel horizontal cracks.

Salt film formation is an occurrence that happens during pit growth. A new perspective on pitting corrosion has been proposed which involves salt film formation as a consequence to pitting corrosion, rather than a requirement for stable pit growth. This paper presents a two-dimensional axial symmetry corrosion model representing a microscale pit in steel. The corrosion activities are studied using a commercial finite element program, COMSOL Multiphysics 5.6. The mass transport is considered and solved using Nernst-Planck resolutions. The model allows the prediction of pit propagation after the initiation state by applying thermodynamics formulas based on Pourbaix diagram of iron and is able to incorporate the salt film formation on the metal surface and produce polarization curve as in published literature. The results show that the salt film forms on the metal surface is in agreement to a newly proposed model, which stated that salt film is as a consequent formation to stable pit growth.

The objective of this work is to explore numerically the effect of the winglet on the aerodynamics performance of the aircraft wing NACA 4415. Three-dimensional governing equation on the wing have been developed. The turbulence was modeled using standard k-epsilon model. The numerical method was carried out using commercial CFD code. The flow fields were plotted and drag and lift coefficients were calculated. The results show that the fluid flow over the wing with winglet was more streamline in comparison with original wing. This makes the drag coefficient is lower, but the lift coefficient is higher. Thus, the performance of the wing with winglet is better.

The main goal of this research is to evaluate the surface roughness level on the performance of journal bearing using the computational fluid dynamics (CFD) method. Aiming to further enhance the acoustic and tribological lubrication performance, a novel heterogeneous rough/smooth pattern is introduced. The results reveal that increasing the roughness level can improve the load support and reduce the bearing noise. However, an undesirable scenario is observed, namely increased friction force of the heterogeneous rough/smooth bearing.

This study aims to analyze the effect of both a single rectangular and a semicircular shape to determine the distribution of pressures on the slider bearings. The results show the rectangular pocket with no slip conditions, the general pressure distribution on the inlet side, the pressure decreases when it enters the pocket. There is no effect of pressure in applying the slip boundary in rectangular pocket. The effect of giving a slip boundary makes a pressure drop of about 6%. The highest pressure increases in the highest Reynolds number, and vice versa. The rectangular pocket is more advantageous than the semicircular shape on the bearing surface.

The aim of this research work is to analyze the Surface Integrity (SI) of Custom-465 hardened steel over end milling process. End milling process with high cutting speeds becomes an economical practice for manufacturing the parts with high quality and accuracy. High speed end milling is now used for machining of hardened steels for making aerospace and automotive components at higher production rate. The effect of operating parameters such as Cutting Speed (CS), Feed (F) and Depth of Cut (DoC) on SI is more important to control the quality of work piece. In this paper the SI studies includes the measurement of surface roughness (Ra), cutting forces and deformation measurement using coordinate measuring machines was discussed. Then the results were made based on the observations and the surface integrities are studied. From the final results it was found that, the percentage of feed contributes more on Material Removal Rate (MRR) with 61.73% and also the MRR increased with enriched feed.

Bio-based oil has been developed as a replacement for conventional lubricants derived from mineral-based and synthetic-based oils, which are harmful to individuals and the environment. The purpose of this study was to develop a nanofluid metalworking fluid using modified jatropha oil (MJO) and 0.025 wt.% of activated carbon (AC) as a nanoparticle. Throughout the turning operation, the tool life of the nanofluid was compared to synthetic ester (SE). As a result, MJO + 0.025wt.% AC has better tribological qualities and has a longer tool life (7000 mm cutting length at 49 min machining time) and suited as environmentally benign metalworking fluid.

Palm ester is a sustainable bio-lubricant derived from plant-based resources. The utilization as base oil for grease formulation is attractive. In this work, the palm bio-grease was formulated with different proportion with calcium complex thickener ranges from 15–19 wt%. The consistency and frictional behaviour were assessed through NLGI grade and wear preventive tests respectively. Results obtained shows the comparable friction behaviour of the palm bio-grease with 19 wt% composition of thickener with commercial grease, indicated the good potential of the formulated palm bio-grease.

Wire strand is a simple machine to use, though it can be complex to analyse. Due to wire strand complex spatial structure, which is constructed from several multi-level components, the experimental setup for stress analysis can be complicated and costly. This paper aimed to determine tensile stress of core wire and helical wire from a prestressed 1 + 6 wire strand subjected to tensile load using ANSYS Finite Element Analysis (FEA). Tensile loads were applied on both core wire and helical wire; bonded contact was considered between core wire and helical wire while contacts between helical wires were not considered. Results indicate that core wire has more significant tensile stress values than the helical wire due to it being subjected to purely tensile load unlike the helical wire. Data trend also conforms to Costello’s model and previously published experimental data. This shows the reliability of FEA as a tool to analyse complex wire strand construction.

In this study, the abrasive effect of glass powder on the thermal properties of the friction material is investigated. The thermal behaviour of the brake block composite was studied to obtain an optimal composition by adding glass powder fractions with a volume of 2%, 4% and 6% as an abrasive. Thermal properties of composite brake blocks, including decomposition rate, glass transition and heat capacity, were evaluated using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The test is carried out in an atmospheric environment according to actual braking conditions. The results showed that the addition of 2% and 4% glass powder abrasives increased the decomposition temperature of the composite specimen. Meanwhile, the addition of glass powder up to 6% showed the decomposition's highest weight loss. The addition of glass powder to the composite brake block increased the average glass transition temperature (ΔTg) and average heat capacity (ΔCp). The highest mean glass transition temperature and heat capacity were found in composites with 6% glass powder.

Diesel injection nozzles are precisely machined in the order of micrometre to produce a fine fuel spray that is crucial for the engine’s combustion and emission efficiency. The injector’s spray quality is dependent on the generation of deposits. This paper studies the deposition in a single-cylinder 4-stroke diesel engine nozzle hole when using higher blended biodiesel blends. Using B10 and B30 palm biodiesel blends in two separate engine runs, two sets of injectors are collected. The injectors are cross-sectioned to reveal the nozzle hole of the injectors. Scanning electron microscope (SEM) analysis of the injector hole surface is presented. The analysis revealed that less deposit formation had been observed for B30 injection nozzles. From this observation, the injectors expected spray performance using a higher percentage of biodiesel blend may be predicted.

The physical properties of the fibre surface have a significant impact on the adhesion and frictional behaviour between fibres at the nano and micro-scale especially in composite materials. This paper focuses on determining the surface energy of an aramid fibre utilising the contact angle measurements with a series of test liquids. Twaron® aramid fibres, both treated and untreated are tested in three different liquids. The results show that treating the surface of the fibre increased the surface energy by approximately 36.7%. It was also discovered that the surface energy of the Twaron® aramid fibre is mostly of polar character, exhibiting a hydrophilic behaviour.

The uncertainty analysis for experimental investigation of bi-directional flow conditions of thermoacoustics is presented. The experimental rig used for loudspeaker as a flow inducer to provide acoustical flow across tube banks that is placed inside a standing wave resonator. The measured velocity and temperature changes within the vicinity of the tube banks are presented along with the uncertainty values. The standard deviation for velocity and temperature data shows that data varies with maximum deviation of 0.14 m/s and 5.78 °C, respectively. The results show that a good repeatability was obtained during the experiments which indicates that a reliable thermal-fluid measurement of bi-directional flow condition was achieved.

This study presents a heat transfer analysis for the oscillatory flow of thermoacoustics. Experimental works and numerical simulation using the Computational Fluid Dynamics (CFD) method were done, and the heat transfer values were calculated and discussed. Results showed that a slight modification in the heat transfer calculation leads to a better representative of heat transfer for oscillatory flow. The results indicate that the direct use of heat transfer correlation that was meant for steady one-directional flow on the calculation of heat transfer for oscillatory flow may not be sufficient in providing the actual insight into the thermal performance in the oscillatory flow model.

Thermoacoustics offer alternative green options for technologies related to cooling and energy generation. This study presents the standing wave models of thermoacoustic refrigerating system with different used of materials for the structure known as stack. The DeltaEC results showed a temperature drop predicted of 264.14 K can be achieved by considering a non-metal material for stack that is placed inside a standing wave thermoacoustic cooler model with resonance frequency of 123 Hz.

Dielectric Barrier Discharge (DBD) plasma actuator has become the well-known tools in the aerodynamics flow control applications. DBD plasma actuator have no moving parts as it only involves in ionization of flow stream, fast reaction, flexible and amazingly low in mass making it good alternative to hydraulic based control system. In this study, numerical simulations of airflow on vehicle spoiler with plasma actuator were performed. The results in terms of aerodynamic performance such as coefficient of drag (CD) and lift coefficient (CL) are presented in this paper. The vehicle spoiler is designed based on NACA 4418 airfoil while the DBD plasma is modeled as the source term in ANSYS-Fluent software. The results suggest that, by having plasma actuator on the top part of the spoiler, there is approximately 3.4% decrease in the value coefficient of drag. As such, DBD plasma actuator can be considered as the flow controller that can be installed in automotive spoiler for better performance.

Plasma can be generated by corona discharge, diaelectric barrier discharge (DBD), arc discharge and microwave power. Microwave plasma has been shown to be utilized to produce hydrogen under atmospheric pressure. Meanwhile, Dielectric Barrier Discharge (DBD) plasma actuator has become the well-known tools in the aerodynamics flow control applications. In this research, two types of plasma were generated by using two different methods. The types of plasma generated are microwave and DBD plasma. The temperature distribution on the plasma surface was measured using infra-red thermal camera. The results suggest that surface temperature of microwave plasma is higher than DBD plasma.

Food drying has been one of the oldest methods for preserving food. The method utilizes the sun as a way of drying any ingredients needed. Over the years, developments have been made to improve drying time to which the invention for an electric powered dehydrator. However, using the simplest method of solar drying is much preferable in countries where consuming electric is costly. Two types of mobile solar dehydrator are presented in this paper, with one used the circular profiled polycarbonate sheet, and the other angular profiled polycarbonate sheet. Experiments were conducted on both dehydrators to seek its preliminary performances. The presented mobile solar dehydrator can also contain heat up to a temperature of 53.5 ℃, given a sunny day weather. Based on the data obtained, the weather plays a huge role on the drying efficiency of the dehydrator. All in all, mobile solar dehydrators do provide a promising alternative to the normal open solar drying method.

In this research, cerium oxide will be used as a fuel additive as it plays a major role in increasing biodiesel performance and improve the properties of the algae-biodiesel blends upon reducing the nitrogen emission and improving the engine performance characteristics. The main phases involved in this research are the extraction of algae oil, blending process of algae biodiesel with cerium oxide and data collection of dynamic viscosity with calorific value. The data collected were used as inputs to Design Expert (DOE) software for identifying the best formula to be blended in terms of dynamic viscosity and calorific value properties. The results obtained from the analysis shows that the final optimum blend obtained by the software showed that the viscosity obtained through this research was significant and the calorific value was conformed to the biodiesel standard. Thus, it proves that cerium oxide as fuel additive assists in improving fuel characteristics in algae biodiesel.

The combustion characteristics of fuel spray can be examined at a basic level by fuel droplet study. Evaporation processes of a fuel droplet involves few combustion phases mainly transient heating phase, steady boiling phase and transient fuel vapour accumulation effect. The combustion phase duration is found to be consistent for a particular type of fuel with fuel vapour accumulation has the shortest duration followed by transient droplet heating and steady boiling phase. With precise quantitative measurement method conducted in the present work, high measurement repeatability is assured thus enabling the determination of droplet combustion stability categorization with clear definition through the duration of combustion phases.

Spray drying is ideal for quickly drying food goods. This research aims to evaluate the influence of incoming airflow direction on the residence duration of particle with varying droplet sizes. The computational fluid dynamics method uses the k-ω SST and the standard k-ε model for flow simulation and particle prediction. The simulation results show that the residence time of the mixed flow is longer than the co-current flow for droplet 50 mm < and faster for droplet > 50 mm. Furthermore, the residence time of the particle changes with increasing droplet diameter; in mixed flow spray dryers, residence time tends to decrease; otherwise, it will increase in the co-current flow model.

The paper reports the prediction of oscillatory flow conditions inside a standing wave thermoacoustic resonator by using the Design Environment for Low-amplitude Thermoacoustic Engines (DeltaEC) software. A 6.6 m long resonator is designed with an oscillating frequency of 14.2 Hz. A design of fourteen blocks is tested and velocity changes across the rig are reported. Flow is varied with drive ratios starting from 0.65% to 3%. The results confirmed that the design follows the standing wave criteria as predicted by the theory. Due to simplification utilized by DeltaEC, it is found that the software is unable to provide detail information of temperature change across all parts inside the resonator. Different method will be needed to confirm the temperature variations within the system, but in general DeltaEC does provide sufficient information for designing purpose of the thermoacoustic system.

High accuracy and dynamic range have been some of the most prominent challenges when it comes to non-equilibrium turbulence measurements. LDA is one of the most preferred measurements techniques in these challenging turbulent flow measurements for its unique favorable properties in various experimental investigations. The current commercial hardware-driven LDA systems however suffer from practical limitations in accurately representing long and short residence times. A novel software-driven LDA, has therefore been developed to enhance the measurement quality and the dynamic range. A round turbulent jet has been used as the test bed that is similar to the one used for previous measurements with a typical commercial LDA. Both data are diagnosed for dynamic range in residence times and compared to each other. Much longer residence times is captured at the lowest (near zero) velocities by the novel LDA compared to that of the commercial one, which maximum value is abruptly limited at the outermost off-axis positions (52 mm).

Adhesively bonded connections are now commonly employed in products that may be subjected to a variety of environmental conditions. Temperature fluctuations are an element that may inflict damage on adhesive joints and lead to interconnection failure. The objective of this work is to investigate the effect of temperature on the joints bonded with electrically conductive adhesive. Adhesive joints were exposed to high and low temperatures at 85 °C and 6 °C respectively for 10, 30, and 50 h. The shear strength of the joints, which were represented by single lap joints was obtained from tensile tests. The effect of temperature was also observed on the fracture surfaces of the adhesive joints measured by a 3D profilometer. Results indicated that exposure to high temperatures increased the performance of adhesive joints significantly. The strength of adhesive joints increased as the hours of exposure to high temperatures increased. It can be concluded that at low temperature, the surface of the electrically conductive adhesive becomes more ductile due to the number and frequency of lower peak, while at high temperature, the surface of electrically conductive adhesive becomes more brittle due to the number and frequency of the higher peak.